Eric Lee / smarc-fsl-linux-kernel

trace.c 153 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 2526 2527 2528 2529 2530 2531 2532 2533 2534 2535 2536 2537 2538 2539 2540 2541 2542 2543 2544 2545 2546 2547 2548 2549 2550 2551 2552 2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563 2564 2565 2566 2567 2568 2569 2570 2571 2572 2573 2574 2575 2576 2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587 2588 2589 2590 2591 2592 2593 2594 2595 2596 2597 2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608 2609 2610 2611 2612 2613 2614 2615 2616 2617 2618 2619 2620 2621 2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632 2633 2634 2635 2636 2637 2638 2639 2640 2641 2642 2643 2644 2645 2646 2647 2648 2649 2650 2651 2652 2653 2654 2655 2656 2657 2658 2659 2660 2661 2662 2663 2664 2665 2666 2667 2668 2669 2670 2671 2672 2673 2674 2675 2676 2677 2678 2679 2680 2681 2682 2683 2684 2685 2686 2687 2688 2689 2690 2691 2692 2693 2694 2695 2696 2697 2698 2699 2700 2701 2702 2703 2704 2705 2706 2707 2708 2709 2710 2711 2712 2713 2714 2715 2716 2717 2718 2719 2720 2721 2722 2723 2724 2725 2726 2727 2728 2729 2730 2731 2732 2733 2734 2735 2736 2737 2738 2739 2740 2741 2742 2743 2744 2745 2746 2747 2748 2749 2750 2751 2752 2753 2754 2755 2756 2757 2758 2759 2760 2761 2762 2763 2764 2765 2766 2767 2768 2769 2770 2771 2772 2773 2774 2775 2776 2777 2778 2779 2780 2781 2782 2783 2784 2785 2786 2787 2788 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798 2799 2800 2801 2802 2803 2804 2805 2806 2807 2808 2809 2810 2811 2812 2813 2814 2815 2816 2817 2818 2819 2820 2821 2822 2823 2824 2825 2826 2827 2828 2829 2830 2831 2832 2833 2834 2835 2836 2837 2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 2848 2849 2850 2851 2852 2853 2854 2855 2856 2857 2858 2859 2860 2861 2862 2863 2864 2865 2866 2867 2868 2869 2870 2871 2872 2873 2874 2875 2876 2877 2878 2879 2880 2881 2882 2883 2884 2885 2886 2887 2888 2889 2890 2891 2892 2893 2894 2895 2896 2897 2898 2899 2900 2901 2902 2903 2904 2905 2906 2907 2908 2909 2910 2911 2912 2913 2914 2915 2916 2917 2918 2919 2920 2921 2922 2923 2924 2925 2926 2927 2928 2929 2930 2931 2932 2933 2934 2935 2936 2937 2938 2939 2940 2941 2942 2943 2944 2945 2946 2947 2948 2949 2950 2951 2952 2953 2954 2955 2956 2957 2958 2959 2960 2961 2962 2963 2964 2965 2966 2967 2968 2969 2970 2971 2972 2973 2974 2975 2976 2977 2978 2979 2980 2981 2982 2983 2984 2985 2986 2987 2988 2989 2990 2991 2992 2993 2994 2995 2996 2997 2998 2999 3000 3001 3002 3003 3004 3005 3006 3007 3008 3009 3010 3011 3012 3013 3014 3015 3016 3017 3018 3019 3020 3021 3022 3023 3024 3025 3026 3027 3028 3029 3030 3031 3032 3033 3034 3035 3036 3037 3038 3039 3040 3041 3042 3043 3044 3045 3046 3047 3048 3049 3050 3051 3052 3053 3054 3055 3056 3057 3058 3059 3060 3061 3062 3063 3064 3065 3066 3067 3068 3069 3070 3071 3072 3073 3074 3075 3076 3077 3078 3079 3080 3081 3082 3083 3084 3085 3086 3087 3088 3089 3090 3091 3092 3093 3094 3095 3096 3097 3098 3099 3100 3101 3102 3103 3104 3105 3106 3107 3108 3109 3110 3111 3112 3113 3114 3115 3116 3117 3118 3119 3120 3121 3122 3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 3133 3134 3135 3136 3137 3138 3139 3140 3141 3142 3143 3144 3145 3146 3147 3148 3149 3150 3151 3152 3153 3154 3155 3156 3157 3158 3159 3160 3161 3162 3163 3164 3165 3166 3167 3168 3169 3170 3171 3172 3173 3174 3175 3176 3177 3178 3179 3180 3181 3182 3183 3184 3185 3186 3187 3188 3189 3190 3191 3192 3193 3194 3195 3196 3197 3198 3199 3200 3201 3202 3203 3204 3205 3206 3207 3208 3209 3210 3211 3212 3213 3214 3215 3216 3217 3218 3219 3220 3221 3222 3223 3224 3225 3226 3227 3228 3229 3230 3231 3232 3233 3234 3235 3236 3237 3238 3239 3240 3241 3242 3243 3244 3245 3246 3247 3248 3249 3250 3251 3252 3253 3254 3255 3256 3257 3258 3259 3260 3261 3262 3263 3264 3265 3266 3267 3268 3269 3270 3271 3272 3273 3274 3275 3276 3277 3278 3279 3280 3281 3282 3283 3284 3285 3286 3287 3288 3289 3290 3291 3292 3293 3294 3295 3296 3297 3298 3299 3300 3301 3302 3303 3304 3305 3306 3307 3308 3309 3310 3311 3312 3313 3314 3315 3316 3317 3318 3319 3320 3321 3322 3323 3324 3325 3326 3327 3328 3329 3330 3331 3332 3333 3334 3335 3336 3337 3338 3339 3340 3341 3342 3343 3344 3345 3346 3347 3348 3349 3350 3351 3352 3353 3354 3355 3356 3357 3358 3359 3360 3361 3362 3363 3364 3365 3366 3367 3368 3369 3370 3371 3372 3373 3374 3375 3376 3377 3378 3379 3380 3381 3382 3383 3384 3385 3386 3387 3388 3389 3390 3391 3392 3393 3394 3395 3396 3397 3398 3399 3400 3401 3402 3403 3404 3405 3406 3407 3408 3409 3410 3411 3412 3413 3414 3415 3416 3417 3418 3419 3420 3421 3422 3423 3424 3425 3426 3427 3428 3429 3430 3431 3432 3433 3434 3435 3436 3437 3438 3439 3440 3441 3442 3443 3444 3445 3446 3447 3448 3449 3450 3451 3452 3453 3454 3455 3456 3457 3458 3459 3460 3461 3462 3463 3464 3465 3466 3467 3468 3469 3470 3471 3472 3473 3474 3475 3476 3477 3478 3479 3480 3481 3482 3483 3484 3485 3486 3487 3488 3489 3490 3491 3492 3493 3494 3495 3496 3497 3498 3499 3500 3501 3502 3503 3504 3505 3506 3507 3508 3509 3510 3511 3512 3513 3514 3515 3516 3517 3518 3519 3520 3521 3522 3523 3524 3525 3526 3527 3528 3529 3530 3531 3532 3533 3534 3535 3536 3537 3538 3539 3540 3541 3542 3543 3544 3545 3546 3547 3548 3549 3550 3551 3552 3553 3554 3555 3556 3557 3558 3559 3560 3561 3562 3563 3564 3565 3566 3567 3568 3569 3570 3571 3572 3573 3574 3575 3576 3577 3578 3579 3580 3581 3582 3583 3584 3585 3586 3587 3588 3589 3590 3591 3592 3593 3594 3595 3596 3597 3598 3599 3600 3601 3602 3603 3604 3605 3606 3607 3608 3609 3610 3611 3612 3613 3614 3615 3616 3617 3618 3619 3620 3621 3622 3623 3624 3625 3626 3627 3628 3629 3630 3631 3632 3633 3634 3635 3636 3637 3638 3639 3640 3641 3642 3643 3644 3645 3646 3647 3648 3649 3650 3651 3652 3653 3654 3655 3656 3657 3658 3659 3660 3661 3662 3663 3664 3665 3666 3667 3668 3669 3670 3671 3672 3673 3674 3675 3676 3677 3678 3679 3680 3681 3682 3683 3684 3685 3686 3687 3688 3689 3690 3691 3692 3693 3694 3695 3696 3697 3698 3699 3700 3701 3702 3703 3704 3705 3706 3707 3708 3709 3710 3711 3712 3713 3714 3715 3716 3717 3718 3719 3720 3721 3722 3723 3724 3725 3726 3727 3728 3729 3730 3731 3732 3733 3734 3735 3736 3737 3738 3739 3740 3741 3742 3743 3744 3745 3746 3747 3748 3749 3750 3751 3752 3753 3754 3755 3756 3757 3758 3759 3760 3761 3762 3763 3764 3765 3766 3767 3768 3769 3770 3771 3772 3773 3774 3775 3776 3777 3778 3779 3780 3781 3782 3783 3784 3785 3786 3787 3788 3789 3790 3791 3792 3793 3794 3795 3796 3797 3798 3799 3800 3801 3802 3803 3804 3805 3806 3807 3808 3809 3810 3811 3812 3813 3814 3815 3816 3817 3818 3819 3820 3821 3822 3823 3824 3825 3826 3827 3828 3829 3830 3831 3832 3833 3834 3835 3836 3837 3838 3839 3840 3841 3842 3843 3844 3845 3846 3847 3848 3849 3850 3851 3852 3853 3854 3855 3856 3857 3858 3859 3860 3861 3862 3863 3864 3865 3866 3867 3868 3869 3870 3871 3872 3873 3874 3875 3876 3877 3878 3879 3880 3881 3882 3883 3884 3885 3886 3887 3888 3889 3890 3891 3892 3893 3894 3895 3896 3897 3898 3899 3900 3901 3902 3903 3904 3905 3906 3907 3908 3909 3910 3911 3912 3913 3914 3915 3916 3917 3918 3919 3920 3921 3922 3923 3924 3925 3926 3927 3928 3929 3930 3931 3932 3933 3934 3935 3936 3937 3938 3939 3940 3941 3942 3943 3944 3945 3946 3947 3948 3949 3950 3951 3952 3953 3954 3955 3956 3957 3958 3959 3960 3961 3962 3963 3964 3965 3966 3967 3968 3969 3970 3971 3972 3973 3974 3975 3976 3977 3978 3979 3980 3981 3982 3983 3984 3985 3986 3987 3988 3989 3990 3991 3992 3993 3994 3995 3996 3997 3998 3999 4000 4001 4002 4003 4004 4005 4006 4007 4008 4009 4010 4011 4012 4013 4014 4015 4016 4017 4018 4019 4020 4021 4022 4023 4024 4025 4026 4027 4028 4029 4030 4031 4032 4033 4034 4035 4036 4037 4038 4039 4040 4041 4042 4043 4044 4045 4046 4047 4048 4049 4050 4051 4052 4053 4054 4055 4056 4057 4058 4059 4060 4061 4062 4063 4064 4065 4066 4067 4068 4069 4070 4071 4072 4073 4074 4075 4076 4077 4078 4079 4080 4081 4082 4083 4084 4085 4086 4087 4088 4089 4090 4091 4092 4093 4094 4095 4096 4097 4098 4099 4100 4101 4102 4103 4104 4105 4106 4107 4108 4109 4110 4111 4112 4113 4114 4115 4116 4117 4118 4119 4120 4121 4122 4123 4124 4125 4126 4127 4128 4129 4130 4131 4132 4133 4134 4135 4136 4137 4138 4139 4140 4141 4142 4143 4144 4145 4146 4147 4148 4149 4150 4151 4152 4153 4154 4155 4156 4157 4158 4159 4160 4161 4162 4163 4164 4165 4166 4167 4168 4169 4170 4171 4172 4173 4174 4175 4176 4177 4178 4179 4180 4181 4182 4183 4184 4185 4186 4187 4188 4189 4190 4191 4192 4193 4194 4195 4196 4197 4198 4199 4200 4201 4202 4203 4204 4205 4206 4207 4208 4209 4210 4211 4212 4213 4214 4215 4216 4217 4218 4219 4220 4221 4222 4223 4224 4225 4226 4227 4228 4229 4230 4231 4232 4233 4234 4235 4236 4237 4238 4239 4240 4241 4242 4243 4244 4245 4246 4247 4248 4249 4250 4251 4252 4253 4254 4255 4256 4257 4258 4259 4260 4261 4262 4263 4264 4265 4266 4267 4268 4269 4270 4271 4272 4273 4274 4275 4276 4277 4278 4279 4280 4281 4282 4283 4284 4285 4286 4287 4288 4289 4290 4291 4292 4293 4294 4295 4296 4297 4298 4299 4300 4301 4302 4303 4304 4305 4306 4307 4308 4309 4310 4311 4312 4313 4314 4315 4316 4317 4318 4319 4320 4321 4322 4323 4324 4325 4326 4327 4328 4329 4330 4331 4332 4333 4334 4335 4336 4337 4338 4339 4340 4341 4342 4343 4344 4345 4346 4347 4348 4349 4350 4351 4352 4353 4354 4355 4356 4357 4358 4359 4360 4361 4362 4363 4364 4365 4366 4367 4368 4369 4370 4371 4372 4373 4374 4375 4376 4377 4378 4379 4380 4381 4382 4383 4384 4385 4386 4387 4388 4389 4390 4391 4392 4393 4394 4395 4396 4397 4398 4399 4400 4401 4402 4403 4404 4405 4406 4407 4408 4409 4410 4411 4412 4413 4414 4415 4416 4417 4418 4419 4420 4421 4422 4423 4424 4425 4426 4427 4428 4429 4430 4431 4432 4433 4434 4435 4436 4437 4438 4439 4440 4441 4442 4443 4444 4445 4446 4447 4448 4449 4450 4451 4452 4453 4454 4455 4456 4457 4458 4459 4460 4461 4462 4463 4464 4465 4466 4467 4468 4469 4470 4471 4472 4473 4474 4475 4476 4477 4478 4479 4480 4481 4482 4483 4484 4485 4486 4487 4488 4489 4490 4491 4492 4493 4494 4495 4496 4497 4498 4499 4500 4501 4502 4503 4504 4505 4506 4507 4508 4509 4510 4511 4512 4513 4514 4515 4516 4517 4518 4519 4520 4521 4522 4523 4524 4525 4526 4527 4528 4529 4530 4531 4532 4533 4534 4535 4536 4537 4538 4539 4540 4541 4542 4543 4544 4545 4546 4547 4548 4549 4550 4551 4552 4553 4554 4555 4556 4557 4558 4559 4560 4561 4562 4563 4564 4565 4566 4567 4568 4569 4570 4571 4572 4573 4574 4575 4576 4577 4578 4579 4580 4581 4582 4583 4584 4585 4586 4587 4588 4589 4590 4591 4592 4593 4594 4595 4596 4597 4598 4599 4600 4601 4602 4603 4604 4605 4606 4607 4608 4609 4610 4611 4612 4613 4614 4615 4616 4617 4618 4619 4620 4621 4622 4623 4624 4625 4626 4627 4628 4629 4630 4631 4632 4633 4634 4635 4636 4637 4638 4639 4640 4641 4642 4643 4644 4645 4646 4647 4648 4649 4650 4651 4652 4653 4654 4655 4656 4657 4658 4659 4660 4661 4662 4663 4664 4665 4666 4667 4668 4669 4670 4671 4672 4673 4674 4675 4676 4677 4678 4679 4680 4681 4682 4683 4684 4685 4686 4687 4688 4689 4690 4691 4692 4693 4694 4695 4696 4697 4698 4699 4700 4701 4702 4703 4704 4705 4706 4707 4708 4709 4710 4711 4712 4713 4714 4715 4716 4717 4718 4719 4720 4721 4722 4723 4724 4725 4726 4727 4728 4729 4730 4731 4732 4733 4734 4735 4736 4737 4738 4739 4740 4741 4742 4743 4744 4745 4746 4747 4748 4749 4750 4751 4752 4753 4754 4755 4756 4757 4758 4759 4760 4761 4762 4763 4764 4765 4766 4767 4768 4769 4770 4771 4772 4773 4774 4775 4776 4777 4778 4779 4780 4781 4782 4783 4784 4785 4786 4787 4788 4789 4790 4791 4792 4793 4794 4795 4796 4797 4798 4799 4800 4801 4802 4803 4804 4805 4806 4807 4808 4809 4810 4811 4812 4813 4814 4815 4816 4817 4818 4819 4820 4821 4822 4823 4824 4825 4826 4827 4828 4829 4830 4831 4832 4833 4834 4835 4836 4837 4838 4839 4840 4841 4842 4843 4844 4845 4846 4847 4848 4849 4850 4851 4852 4853 4854 4855 4856 4857 4858 4859 4860 4861 4862 4863 4864 4865 4866 4867 4868 4869 4870 4871 4872 4873 4874 4875 4876 4877 4878 4879 4880 4881 4882 4883 4884 4885 4886 4887 4888 4889 4890 4891 4892 4893 4894 4895 4896 4897 4898 4899 4900 4901 4902 4903 4904 4905 4906 4907 4908 4909 4910 4911 4912 4913 4914 4915 4916 4917 4918 4919 4920 4921 4922 4923 4924 4925 4926 4927 4928 4929 4930 4931 4932 4933 4934 4935 4936 4937 4938 4939 4940 4941 4942 4943 4944 4945 4946 4947 4948 4949 4950 4951 4952 4953 4954 4955 4956 4957 4958 4959 4960 4961 4962 4963 4964 4965 4966 4967 4968 4969 4970 4971 4972 4973 4974 4975 4976 4977 4978 4979 4980 4981 4982 4983 4984 4985 4986 4987 4988 4989 4990 4991 4992 4993 4994 4995 4996 4997 4998 4999 5000 5001 5002 5003 5004 5005 5006 5007 5008 5009 5010 5011 5012 5013 5014 5015 5016 5017 5018 5019 5020 5021 5022 5023 5024 5025 5026 5027 5028 5029 5030 5031 5032 5033 5034 5035 5036 5037 5038 5039 5040 5041 5042 5043 5044 5045 5046 5047 5048 5049 5050 5051 5052 5053 5054 5055 5056 5057 5058 5059 5060 5061 5062 5063 5064 5065 5066 5067 5068 5069 5070 5071 5072 5073 5074 5075 5076 5077 5078 5079 5080 5081 5082 5083 5084 5085 5086 5087 5088 5089 5090 5091 5092 5093 5094 5095 5096 5097 5098 5099 5100 5101 5102 5103 5104 5105 5106 5107 5108 5109 5110 5111 5112 5113 5114 5115 5116 5117 5118 5119 5120 5121 5122 5123 5124 5125 5126 5127 5128 5129 5130 5131 5132 5133 5134 5135 5136 5137 5138 5139 5140 5141 5142 5143 5144 5145 5146 5147 5148 5149 5150 5151 5152 5153 5154 5155 5156 5157 5158 5159 5160 5161 5162 5163 5164 5165 5166 5167 5168 5169 5170 5171 5172 5173 5174 5175 5176 5177 5178 5179 5180 5181 5182 5183 5184 5185 5186 5187 5188 5189 5190 5191 5192 5193 5194 5195 5196 5197 5198 5199 5200 5201 5202 5203 5204 5205 5206 5207 5208 5209 5210 5211 5212 5213 5214 5215 5216 5217 5218 5219 5220 5221 5222 5223 5224 5225 5226 5227 5228 5229 5230 5231 5232 5233 5234 5235 5236 5237 5238 5239 5240 5241 5242 5243 5244 5245 5246 5247 5248 5249 5250 5251 5252 5253 5254 5255 5256 5257 5258 5259 5260 5261 5262 5263 5264 5265 5266 5267 5268 5269 5270 5271 5272 5273 5274 5275 5276 5277 5278 5279 5280 5281 5282 5283 5284 5285 5286 5287 5288 5289 5290 5291 5292 5293 5294 5295 5296 5297 5298 5299 5300 5301 5302 5303 5304 5305 5306 5307 5308 5309 5310 5311 5312 5313 5314 5315 5316 5317 5318 5319 5320 5321 5322 5323 5324 5325 5326 5327 5328 5329 5330 5331 5332 5333 5334 5335 5336 5337 5338 5339 5340 5341 5342 5343 5344 5345 5346 5347 5348 5349 5350 5351 5352 5353 5354 5355 5356 5357 5358 5359 5360 5361 5362 5363 5364 5365 5366 5367 5368 5369 5370 5371 5372 5373 5374 5375 5376 5377 5378 5379 5380 5381 5382 5383 5384 5385 5386 5387 5388 5389 5390 5391 5392 5393 5394 5395 5396 5397 5398 5399 5400 5401 5402 5403 5404 5405 5406 5407 5408 5409 5410 5411 5412 5413 5414 5415 5416 5417 5418 5419 5420 5421 5422 5423 5424 5425 5426 5427 5428 5429 5430 5431 5432 5433 5434 5435 5436 5437 5438 5439 5440 5441 5442 5443 5444 5445 5446 5447 5448 5449 5450 5451 5452 5453 5454 5455 5456 5457 5458 5459 5460 5461 5462 5463 5464 5465 5466 5467 5468 5469 5470 5471 5472 5473 5474 5475 5476 5477 5478 5479 5480 5481 5482 5483 5484 5485 5486 5487 5488 5489 5490 5491 5492 5493 5494 5495 5496 5497 5498 5499 5500 5501 5502 5503 5504 5505 5506 5507 5508 5509 5510 5511 5512 5513 5514 5515 5516 5517 5518 5519 5520 5521 5522 5523 5524 5525 5526 5527 5528 5529 5530 5531 5532 5533 5534 5535 5536 5537 5538 5539 5540 5541 5542 5543 5544 5545 5546 5547 5548 5549 5550 5551 5552 5553 5554 5555 5556 5557 5558 5559 5560 5561 5562 5563 5564 5565 5566 5567 5568 5569 5570 5571 5572 5573 5574 5575 5576 5577 5578 5579 5580 5581 5582 5583 5584 5585 5586 5587 5588 5589 5590 5591 5592 5593 5594 5595 5596 5597 5598 5599 5600 5601 5602 5603 5604 5605 5606 5607 5608 5609 5610 5611 5612 5613 5614 5615 5616 5617 5618 5619 5620 5621 5622 5623 5624 5625 5626 5627 5628 5629 5630 5631 5632 5633 5634 5635 5636 5637 5638 5639 5640 5641 5642 5643 5644 5645 5646 5647 5648 5649 5650 5651 5652 5653 5654 5655 5656 5657 5658 5659 5660 5661 5662 5663 5664 5665 5666 5667 5668 5669 5670 5671 5672 5673 5674 5675 5676 5677 5678 5679 5680 5681 5682 5683 5684 5685 5686 5687 5688 5689 5690 5691 5692 5693 5694 5695 5696 5697 5698 5699 5700 5701 5702 5703 5704 5705 5706 5707 5708 5709 5710 5711 5712 5713 5714 5715 5716 5717 5718 5719 5720 5721 5722 5723 5724 5725 5726 5727 5728 5729 5730 5731 5732 5733 5734 5735 5736 5737 5738 5739 5740 5741 5742 5743 5744 5745 5746 5747 5748 5749 5750 5751 5752 5753 5754 5755 5756 5757 5758 5759 5760 5761 5762 5763 5764 5765 5766 5767 5768 5769 5770 5771 5772 5773 5774 5775 5776 5777 5778 5779 5780 5781 5782 5783 5784 5785 5786 5787 5788 5789 5790 5791 5792 5793 5794 5795 5796 5797 5798 5799 5800 5801 5802 5803 5804 5805 5806 5807 5808 5809 5810 5811 5812 5813 5814 5815 5816 5817 5818 5819 5820 5821 5822 5823 5824 5825 5826 5827 5828 5829 5830 5831 5832 5833 5834 5835 5836 5837 5838 5839 5840 5841 5842 5843 5844 5845 5846 5847 5848 5849 5850 5851 5852 5853 5854 5855 5856 5857 5858 5859 5860 5861 5862 5863 5864 5865 5866 5867 5868 5869 5870 5871 5872 5873 5874 5875 5876 5877 5878 5879 5880 5881 5882 5883 5884 5885 5886 5887 5888 5889 5890 5891 5892 5893 5894 5895 5896 5897 5898 5899 5900 5901 5902 5903 5904 5905 5906 5907 5908 5909 5910 5911 5912 5913 5914 5915 5916 5917 5918 5919 5920 5921 5922 5923 5924 5925 5926 5927 5928 5929 5930 5931 5932 5933 5934 5935 5936 5937 5938 5939 5940 5941 5942 5943 5944 5945 5946 5947 5948 5949 5950 5951 5952 5953 5954 5955 5956 5957 5958 5959 5960 5961 5962 5963 5964 5965 5966 5967 5968 5969 5970 5971 5972 5973 5974 5975 5976 5977 5978 5979 5980 5981 5982 5983 5984 5985 5986 5987 5988 5989 5990 5991 5992 5993 5994 5995 5996 5997 5998 5999 6000 6001 6002 6003 6004 6005 6006 6007 6008 6009 6010 6011 6012 6013 6014 6015 6016 6017 6018 6019 6020 6021 6022 6023 6024 6025 6026 6027 6028 6029 6030 6031 6032 6033 6034 6035 6036 6037 6038 6039 6040 6041 6042 6043 6044 6045 6046 6047 6048 6049 6050 6051 6052 6053 6054 6055 6056 6057 6058 6059 6060 6061 6062 6063 6064 6065 6066 6067 6068 6069 6070 6071 6072 6073 6074 6075 6076 6077 6078 6079 6080 6081 6082 6083 6084 6085 6086 6087 6088 6089 6090 6091 6092 6093 6094 6095 6096 6097 6098 6099 6100 6101 6102 6103 6104 6105 6106 6107 6108 6109 6110 6111 6112 6113 6114 6115 6116 6117 6118 6119 6120 6121 6122 6123 6124 6125 6126 6127 6128 6129 6130 6131 6132 6133 6134 6135 6136 6137 6138 6139 6140 6141 6142 6143 6144 6145 6146 6147 6148 6149 6150 6151 6152 6153 6154 6155 6156 6157 6158 6159 6160 6161 6162 6163 6164 6165 6166 6167 6168 6169 6170 6171 6172 6173 6174 6175 6176 6177 6178 6179 6180 6181 6182 6183 6184 6185 6186 6187 6188 6189 6190 6191 6192 6193 6194 6195 6196 6197 6198 6199 6200 6201 6202 6203 6204 6205 6206 6207 6208 6209 6210 6211 6212 6213 6214 6215 6216 6217 6218 6219 6220 6221 6222 6223 6224 6225 6226 6227 6228 6229 6230 6231 6232 6233 6234 6235 6236 6237 6238 6239 6240 6241 6242 6243 6244 6245 6246 6247 6248 6249 6250 6251 6252 6253 6254 6255 6256 6257 6258 6259 6260 6261 6262 6263 6264 6265 6266 6267 6268 6269 6270 6271 6272 6273 6274 6275 6276 6277 6278 6279 6280 6281 6282 6283 6284 6285 6286 6287 6288 6289 6290 6291 6292 6293 6294 6295 6296 6297 6298 6299 6300 6301 6302 6303 6304 6305 6306 6307 6308 6309 6310 6311 6312 6313 6314 6315 6316 6317 6318 6319 6320 6321 6322 6323 6324 6325 6326 6327 6328 6329 6330 6331 6332 6333 6334 6335 6336 6337 6338 6339 6340 6341 6342 6343 6344 6345 6346 6347 6348 6349 6350 6351 6352 6353 6354 6355 6356 6357 6358 6359 6360 6361 6362 6363 6364 6365 6366 6367 6368 6369 6370 6371 6372 6373 6374 6375 6376 6377 6378 6379 6380 6381 6382 6383 6384 6385 6386 6387 6388 6389 6390 6391 6392 6393 6394 6395 6396 6397 6398 6399 6400 6401 6402 6403 6404 6405 6406 6407 6408 6409 6410 6411 6412 6413 6414 6415 6416 6417 6418 6419 6420 6421 6422 6423 6424 6425 6426 6427 6428 6429 6430 6431 6432 6433 6434 6435 6436 6437 6438 6439 6440 6441 6442 6443 6444 6445 6446 6447 6448 6449 6450 6451 6452 6453 6454 6455 6456 6457 6458 6459 6460 6461 6462 6463 6464 6465 6466 6467 6468 6469 6470 6471 6472 6473 6474 6475 6476 6477 6478 6479 6480 6481 6482 6483 6484 6485 
/*
 * ring buffer based function tracer
 *
 * Copyright (C) 2007-2012 Steven Rostedt <srostedt@redhat.com>
 * Copyright (C) 2008 Ingo Molnar <mingo@redhat.com>
 *
 * Originally taken from the RT patch by:
 *    Arnaldo Carvalho de Melo <acme@redhat.com>
 *
 * Based on code from the latency_tracer, that is:
 *  Copyright (C) 2004-2006 Ingo Molnar
 *  Copyright (C) 2004 Nadia Yvette Chambers
 */
#include <linux/ring_buffer.h>
#include <generated/utsrelease.h>
#include <linux/stacktrace.h>
#include <linux/writeback.h>
#include <linux/kallsyms.h>
#include <linux/seq_file.h>
#include <linux/notifier.h>
#include <linux/irqflags.h>
#include <linux/debugfs.h>
#include <linux/pagemap.h>
#include <linux/hardirq.h>
#include <linux/linkage.h>
#include <linux/uaccess.h>
#include <linux/kprobes.h>
#include <linux/ftrace.h>
#include <linux/module.h>
#include <linux/percpu.h>
#include <linux/splice.h>
#include <linux/kdebug.h>
#include <linux/string.h>
#include <linux/rwsem.h>
#include <linux/slab.h>
#include <linux/ctype.h>
#include <linux/init.h>
#include <linux/poll.h>
#include <linux/nmi.h>
#include <linux/fs.h>
#include <linux/sched/rt.h>

#include "trace.h"
#include "trace_output.h"

/*
 * On boot up, the ring buffer is set to the minimum size, so that
 * we do not waste memory on systems that are not using tracing.
 */
bool ring_buffer_expanded;

/*
 * We need to change this state when a selftest is running.
 * A selftest will lurk into the ring-buffer to count the
 * entries inserted during the selftest although some concurrent
 * insertions into the ring-buffer such as trace_printk could occurred
 * at the same time, giving false positive or negative results.
 */
static bool __read_mostly tracing_selftest_running;

/*
 * If a tracer is running, we do not want to run SELFTEST.
 */
bool __read_mostly tracing_selftest_disabled;

/* For tracers that don't implement custom flags */
static struct tracer_opt dummy_tracer_opt[] = {
	{ }
};

static struct tracer_flags dummy_tracer_flags = {
	.val = 0,
	.opts = dummy_tracer_opt
};

static int dummy_set_flag(u32 old_flags, u32 bit, int set)
{
	return 0;
}

/*
 * To prevent the comm cache from being overwritten when no
 * tracing is active, only save the comm when a trace event
 * occurred.
 */
static DEFINE_PER_CPU(bool, trace_cmdline_save);

/*
 * Kill all tracing for good (never come back).
 * It is initialized to 1 but will turn to zero if the initialization
 * of the tracer is successful. But that is the only place that sets
 * this back to zero.
 */
static int tracing_disabled = 1;

DEFINE_PER_CPU(int, ftrace_cpu_disabled);

cpumask_var_t __read_mostly	tracing_buffer_mask;

/*
 * ftrace_dump_on_oops - variable to dump ftrace buffer on oops
 *
 * If there is an oops (or kernel panic) and the ftrace_dump_on_oops
 * is set, then ftrace_dump is called. This will output the contents
 * of the ftrace buffers to the console.  This is very useful for
 * capturing traces that lead to crashes and outputing it to a
 * serial console.
 *
 * It is default off, but you can enable it with either specifying
 * "ftrace_dump_on_oops" in the kernel command line, or setting
 * /proc/sys/kernel/ftrace_dump_on_oops
 * Set 1 if you want to dump buffers of all CPUs
 * Set 2 if you want to dump the buffer of the CPU that triggered oops
 */

enum ftrace_dump_mode ftrace_dump_on_oops;

static int tracing_set_tracer(const char *buf);

#define MAX_TRACER_SIZE		100
static char bootup_tracer_buf[MAX_TRACER_SIZE] __initdata;
static char *default_bootup_tracer;

static bool allocate_snapshot;

static int __init set_cmdline_ftrace(char *str)
{
	strlcpy(bootup_tracer_buf, str, MAX_TRACER_SIZE);
	default_bootup_tracer = bootup_tracer_buf;
	/* We are using ftrace early, expand it */
	ring_buffer_expanded = true;
	return 1;
}
__setup("ftrace=", set_cmdline_ftrace);

static int __init set_ftrace_dump_on_oops(char *str)
{
	if (*str++ != '=' || !*str) {
		ftrace_dump_on_oops = DUMP_ALL;
		return 1;
	}

	if (!strcmp("orig_cpu", str)) {
		ftrace_dump_on_oops = DUMP_ORIG;
                return 1;
        }

        return 0;
}
__setup("ftrace_dump_on_oops", set_ftrace_dump_on_oops);

static int __init boot_alloc_snapshot(char *str)
{
	allocate_snapshot = true;
	/* We also need the main ring buffer expanded */
	ring_buffer_expanded = true;
	return 1;
}
__setup("alloc_snapshot", boot_alloc_snapshot);


static char trace_boot_options_buf[MAX_TRACER_SIZE] __initdata;
static char *trace_boot_options __initdata;

static int __init set_trace_boot_options(char *str)
{
	strlcpy(trace_boot_options_buf, str, MAX_TRACER_SIZE);
	trace_boot_options = trace_boot_options_buf;
	return 0;
}
__setup("trace_options=", set_trace_boot_options);

unsigned long long ns2usecs(cycle_t nsec)
{
	nsec += 500;
	do_div(nsec, 1000);
	return nsec;
}

/*
 * The global_trace is the descriptor that holds the tracing
 * buffers for the live tracing. For each CPU, it contains
 * a link list of pages that will store trace entries. The
 * page descriptor of the pages in the memory is used to hold
 * the link list by linking the lru item in the page descriptor
 * to each of the pages in the buffer per CPU.
 *
 * For each active CPU there is a data field that holds the
 * pages for the buffer for that CPU. Each CPU has the same number
 * of pages allocated for its buffer.
 */
static struct trace_array	global_trace;

LIST_HEAD(ftrace_trace_arrays);

int trace_array_get(struct trace_array *this_tr)
{
	struct trace_array *tr;
	int ret = -ENODEV;

	mutex_lock(&trace_types_lock);
	list_for_each_entry(tr, &ftrace_trace_arrays, list) {
		if (tr == this_tr) {
			tr->ref++;
			ret = 0;
			break;
		}
	}
	mutex_unlock(&trace_types_lock);

	return ret;
}

static void __trace_array_put(struct trace_array *this_tr)
{
	WARN_ON(!this_tr->ref);
	this_tr->ref--;
}

void trace_array_put(struct trace_array *this_tr)
{
	mutex_lock(&trace_types_lock);
	__trace_array_put(this_tr);
	mutex_unlock(&trace_types_lock);
}

int filter_current_check_discard(struct ring_buffer *buffer,
				 struct ftrace_event_call *call, void *rec,
				 struct ring_buffer_event *event)
{
	return filter_check_discard(call, rec, buffer, event);
}
EXPORT_SYMBOL_GPL(filter_current_check_discard);

cycle_t buffer_ftrace_now(struct trace_buffer *buf, int cpu)
{
	u64 ts;

	/* Early boot up does not have a buffer yet */
	if (!buf->buffer)
		return trace_clock_local();

	ts = ring_buffer_time_stamp(buf->buffer, cpu);
	ring_buffer_normalize_time_stamp(buf->buffer, cpu, &ts);

	return ts;
}

cycle_t ftrace_now(int cpu)
{
	return buffer_ftrace_now(&global_trace.trace_buffer, cpu);
}

/**
 * tracing_is_enabled - Show if global_trace has been disabled
 *
 * Shows if the global trace has been enabled or not. It uses the
 * mirror flag "buffer_disabled" to be used in fast paths such as for
 * the irqsoff tracer. But it may be inaccurate due to races. If you
 * need to know the accurate state, use tracing_is_on() which is a little
 * slower, but accurate.
 */
int tracing_is_enabled(void)
{
	/*
	 * For quick access (irqsoff uses this in fast path), just
	 * return the mirror variable of the state of the ring buffer.
	 * It's a little racy, but we don't really care.
	 */
	smp_rmb();
	return !global_trace.buffer_disabled;
}

/*
 * trace_buf_size is the size in bytes that is allocated
 * for a buffer. Note, the number of bytes is always rounded
 * to page size.
 *
 * This number is purposely set to a low number of 16384.
 * If the dump on oops happens, it will be much appreciated
 * to not have to wait for all that output. Anyway this can be
 * boot time and run time configurable.
 */
#define TRACE_BUF_SIZE_DEFAULT	1441792UL /* 16384 * 88 (sizeof(entry)) */

static unsigned long		trace_buf_size = TRACE_BUF_SIZE_DEFAULT;

/* trace_types holds a link list of available tracers. */
static struct tracer		*trace_types __read_mostly;

/*
 * trace_types_lock is used to protect the trace_types list.
 */
DEFINE_MUTEX(trace_types_lock);

/*
 * serialize the access of the ring buffer
 *
 * ring buffer serializes readers, but it is low level protection.
 * The validity of the events (which returns by ring_buffer_peek() ..etc)
 * are not protected by ring buffer.
 *
 * The content of events may become garbage if we allow other process consumes
 * these events concurrently:
 *   A) the page of the consumed events may become a normal page
 *      (not reader page) in ring buffer, and this page will be rewrited
 *      by events producer.
 *   B) The page of the consumed events may become a page for splice_read,
 *      and this page will be returned to system.
 *
 * These primitives allow multi process access to different cpu ring buffer
 * concurrently.
 *
 * These primitives don't distinguish read-only and read-consume access.
 * Multi read-only access are also serialized.
 */

#ifdef CONFIG_SMP
static DECLARE_RWSEM(all_cpu_access_lock);
static DEFINE_PER_CPU(struct mutex, cpu_access_lock);

static inline void trace_access_lock(int cpu)
{
	if (cpu == RING_BUFFER_ALL_CPUS) {
		/* gain it for accessing the whole ring buffer. */
		down_write(&all_cpu_access_lock);
	} else {
		/* gain it for accessing a cpu ring buffer. */

		/* Firstly block other trace_access_lock(RING_BUFFER_ALL_CPUS). */
		down_read(&all_cpu_access_lock);

		/* Secondly block other access to this @cpu ring buffer. */
		mutex_lock(&per_cpu(cpu_access_lock, cpu));
	}
}

static inline void trace_access_unlock(int cpu)
{
	if (cpu == RING_BUFFER_ALL_CPUS) {
		up_write(&all_cpu_access_lock);
	} else {
		mutex_unlock(&per_cpu(cpu_access_lock, cpu));
		up_read(&all_cpu_access_lock);
	}
}

static inline void trace_access_lock_init(void)
{
	int cpu;

	for_each_possible_cpu(cpu)
		mutex_init(&per_cpu(cpu_access_lock, cpu));
}

#else

static DEFINE_MUTEX(access_lock);

static inline void trace_access_lock(int cpu)
{
	(void)cpu;
	mutex_lock(&access_lock);
}

static inline void trace_access_unlock(int cpu)
{
	(void)cpu;
	mutex_unlock(&access_lock);
}

static inline void trace_access_lock_init(void)
{
}

#endif

/* trace_flags holds trace_options default values */
unsigned long trace_flags = TRACE_ITER_PRINT_PARENT | TRACE_ITER_PRINTK |
	TRACE_ITER_ANNOTATE | TRACE_ITER_CONTEXT_INFO | TRACE_ITER_SLEEP_TIME |
	TRACE_ITER_GRAPH_TIME | TRACE_ITER_RECORD_CMD | TRACE_ITER_OVERWRITE |
	TRACE_ITER_IRQ_INFO | TRACE_ITER_MARKERS | TRACE_ITER_FUNCTION;

void tracer_tracing_on(struct trace_array *tr)
{
	if (tr->trace_buffer.buffer)
		ring_buffer_record_on(tr->trace_buffer.buffer);
	/*
	 * This flag is looked at when buffers haven't been allocated
	 * yet, or by some tracers (like irqsoff), that just want to
	 * know if the ring buffer has been disabled, but it can handle
	 * races of where it gets disabled but we still do a record.
	 * As the check is in the fast path of the tracers, it is more
	 * important to be fast than accurate.
	 */
	tr->buffer_disabled = 0;
	/* Make the flag seen by readers */
	smp_wmb();
}

/**
 * tracing_on - enable tracing buffers
 *
 * This function enables tracing buffers that may have been
 * disabled with tracing_off.
 */
void tracing_on(void)
{
	tracer_tracing_on(&global_trace);
}
EXPORT_SYMBOL_GPL(tracing_on);

/**
 * __trace_puts - write a constant string into the trace buffer.
 * @ip:	   The address of the caller
 * @str:   The constant string to write
 * @size:  The size of the string.
 */
int __trace_puts(unsigned long ip, const char *str, int size)
{
	struct ring_buffer_event *event;
	struct ring_buffer *buffer;
	struct print_entry *entry;
	unsigned long irq_flags;
	int alloc;

	alloc = sizeof(*entry) + size + 2; /* possible \n added */

	local_save_flags(irq_flags);
	buffer = global_trace.trace_buffer.buffer;
	event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, alloc, 
					  irq_flags, preempt_count());
	if (!event)
		return 0;

	entry = ring_buffer_event_data(event);
	entry->ip = ip;

	memcpy(&entry->buf, str, size);

	/* Add a newline if necessary */
	if (entry->buf[size - 1] != '\n') {
		entry->buf[size] = '\n';
		entry->buf[size + 1] = '\0';
	} else
		entry->buf[size] = '\0';

	__buffer_unlock_commit(buffer, event);

	return size;
}
EXPORT_SYMBOL_GPL(__trace_puts);

/**
 * __trace_bputs - write the pointer to a constant string into trace buffer
 * @ip:	   The address of the caller
 * @str:   The constant string to write to the buffer to
 */
int __trace_bputs(unsigned long ip, const char *str)
{
	struct ring_buffer_event *event;
	struct ring_buffer *buffer;
	struct bputs_entry *entry;
	unsigned long irq_flags;
	int size = sizeof(struct bputs_entry);

	local_save_flags(irq_flags);
	buffer = global_trace.trace_buffer.buffer;
	event = trace_buffer_lock_reserve(buffer, TRACE_BPUTS, size,
					  irq_flags, preempt_count());
	if (!event)
		return 0;

	entry = ring_buffer_event_data(event);
	entry->ip			= ip;
	entry->str			= str;

	__buffer_unlock_commit(buffer, event);

	return 1;
}
EXPORT_SYMBOL_GPL(__trace_bputs);

#ifdef CONFIG_TRACER_SNAPSHOT
/**
 * trace_snapshot - take a snapshot of the current buffer.
 *
 * This causes a swap between the snapshot buffer and the current live
 * tracing buffer. You can use this to take snapshots of the live
 * trace when some condition is triggered, but continue to trace.
 *
 * Note, make sure to allocate the snapshot with either
 * a tracing_snapshot_alloc(), or by doing it manually
 * with: echo 1 > /sys/kernel/debug/tracing/snapshot
 *
 * If the snapshot buffer is not allocated, it will stop tracing.
 * Basically making a permanent snapshot.
 */
void tracing_snapshot(void)
{
	struct trace_array *tr = &global_trace;
	struct tracer *tracer = tr->current_trace;
	unsigned long flags;

	if (in_nmi()) {
		internal_trace_puts("*** SNAPSHOT CALLED FROM NMI CONTEXT ***\n");
		internal_trace_puts("*** snapshot is being ignored        ***\n");
		return;
	}

	if (!tr->allocated_snapshot) {
		internal_trace_puts("*** SNAPSHOT NOT ALLOCATED ***\n");
		internal_trace_puts("*** stopping trace here!   ***\n");
		tracing_off();
		return;
	}

	/* Note, snapshot can not be used when the tracer uses it */
	if (tracer->use_max_tr) {
		internal_trace_puts("*** LATENCY TRACER ACTIVE ***\n");
		internal_trace_puts("*** Can not use snapshot (sorry) ***\n");
		return;
	}

	local_irq_save(flags);
	update_max_tr(tr, current, smp_processor_id());
	local_irq_restore(flags);
}
EXPORT_SYMBOL_GPL(tracing_snapshot);

static int resize_buffer_duplicate_size(struct trace_buffer *trace_buf,
					struct trace_buffer *size_buf, int cpu_id);
static void set_buffer_entries(struct trace_buffer *buf, unsigned long val);

static int alloc_snapshot(struct trace_array *tr)
{
	int ret;

	if (!tr->allocated_snapshot) {

		/* allocate spare buffer */
		ret = resize_buffer_duplicate_size(&tr->max_buffer,
				   &tr->trace_buffer, RING_BUFFER_ALL_CPUS);
		if (ret < 0)
			return ret;

		tr->allocated_snapshot = true;
	}

	return 0;
}

void free_snapshot(struct trace_array *tr)
{
	/*
	 * We don't free the ring buffer. instead, resize it because
	 * The max_tr ring buffer has some state (e.g. ring->clock) and
	 * we want preserve it.
	 */
	ring_buffer_resize(tr->max_buffer.buffer, 1, RING_BUFFER_ALL_CPUS);
	set_buffer_entries(&tr->max_buffer, 1);
	tracing_reset_online_cpus(&tr->max_buffer);
	tr->allocated_snapshot = false;
}

/**
 * trace_snapshot_alloc - allocate and take a snapshot of the current buffer.
 *
 * This is similar to trace_snapshot(), but it will allocate the
 * snapshot buffer if it isn't already allocated. Use this only
 * where it is safe to sleep, as the allocation may sleep.
 *
 * This causes a swap between the snapshot buffer and the current live
 * tracing buffer. You can use this to take snapshots of the live
 * trace when some condition is triggered, but continue to trace.
 */
void tracing_snapshot_alloc(void)
{
	struct trace_array *tr = &global_trace;
	int ret;

	ret = alloc_snapshot(tr);
	if (WARN_ON(ret < 0))
		return;

	tracing_snapshot();
}
EXPORT_SYMBOL_GPL(tracing_snapshot_alloc);
#else
void tracing_snapshot(void)
{
	WARN_ONCE(1, "Snapshot feature not enabled, but internal snapshot used");
}
EXPORT_SYMBOL_GPL(tracing_snapshot);
void tracing_snapshot_alloc(void)
{
	/* Give warning */
	tracing_snapshot();
}
EXPORT_SYMBOL_GPL(tracing_snapshot_alloc);
#endif /* CONFIG_TRACER_SNAPSHOT */

void tracer_tracing_off(struct trace_array *tr)
{
	if (tr->trace_buffer.buffer)
		ring_buffer_record_off(tr->trace_buffer.buffer);
	/*
	 * This flag is looked at when buffers haven't been allocated
	 * yet, or by some tracers (like irqsoff), that just want to
	 * know if the ring buffer has been disabled, but it can handle
	 * races of where it gets disabled but we still do a record.
	 * As the check is in the fast path of the tracers, it is more
	 * important to be fast than accurate.
	 */
	tr->buffer_disabled = 1;
	/* Make the flag seen by readers */
	smp_wmb();
}

/**
 * tracing_off - turn off tracing buffers
 *
 * This function stops the tracing buffers from recording data.
 * It does not disable any overhead the tracers themselves may
 * be causing. This function simply causes all recording to
 * the ring buffers to fail.
 */
void tracing_off(void)
{
	tracer_tracing_off(&global_trace);
}
EXPORT_SYMBOL_GPL(tracing_off);

/**
 * tracer_tracing_is_on - show real state of ring buffer enabled
 * @tr : the trace array to know if ring buffer is enabled
 *
 * Shows real state of the ring buffer if it is enabled or not.
 */
int tracer_tracing_is_on(struct trace_array *tr)
{
	if (tr->trace_buffer.buffer)
		return ring_buffer_record_is_on(tr->trace_buffer.buffer);
	return !tr->buffer_disabled;
}

/**
 * tracing_is_on - show state of ring buffers enabled
 */
int tracing_is_on(void)
{
	return tracer_tracing_is_on(&global_trace);
}
EXPORT_SYMBOL_GPL(tracing_is_on);

static int __init set_buf_size(char *str)
{
	unsigned long buf_size;

	if (!str)
		return 0;
	buf_size = memparse(str, &str);
	/* nr_entries can not be zero */
	if (buf_size == 0)
		return 0;
	trace_buf_size = buf_size;
	return 1;
}
__setup("trace_buf_size=", set_buf_size);

static int __init set_tracing_thresh(char *str)
{
	unsigned long threshold;
	int ret;

	if (!str)
		return 0;
	ret = kstrtoul(str, 0, &threshold);
	if (ret < 0)
		return 0;
	tracing_thresh = threshold * 1000;
	return 1;
}
__setup("tracing_thresh=", set_tracing_thresh);

unsigned long nsecs_to_usecs(unsigned long nsecs)
{
	return nsecs / 1000;
}

/* These must match the bit postions in trace_iterator_flags */
static const char *trace_options[] = {
	"print-parent",
	"sym-offset",
	"sym-addr",
	"verbose",
	"raw",
	"hex",
	"bin",
	"block",
	"stacktrace",
	"trace_printk",
	"ftrace_preempt",
	"branch",
	"annotate",
	"userstacktrace",
	"sym-userobj",
	"printk-msg-only",
	"context-info",
	"latency-format",
	"sleep-time",
	"graph-time",
	"record-cmd",
	"overwrite",
	"disable_on_free",
	"irq-info",
	"markers",
	"function-trace",
	NULL
};

static struct {
	u64 (*func)(void);
	const char *name;
	int in_ns;		/* is this clock in nanoseconds? */
} trace_clocks[] = {
	{ trace_clock_local,	"local",	1 },
	{ trace_clock_global,	"global",	1 },
	{ trace_clock_counter,	"counter",	0 },
	{ trace_clock_jiffies,	"uptime",	1 },
	{ trace_clock,		"perf",		1 },
	ARCH_TRACE_CLOCKS
};

/*
 * trace_parser_get_init - gets the buffer for trace parser
 */
int trace_parser_get_init(struct trace_parser *parser, int size)
{
	memset(parser, 0, sizeof(*parser));

	parser->buffer = kmalloc(size, GFP_KERNEL);
	if (!parser->buffer)
		return 1;

	parser->size = size;
	return 0;
}

/*
 * trace_parser_put - frees the buffer for trace parser
 */
void trace_parser_put(struct trace_parser *parser)
{
	kfree(parser->buffer);
}

/*
 * trace_get_user - reads the user input string separated by  space
 * (matched by isspace(ch))
 *
 * For each string found the 'struct trace_parser' is updated,
 * and the function returns.
 *
 * Returns number of bytes read.
 *
 * See kernel/trace/trace.h for 'struct trace_parser' details.
 */
int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
	size_t cnt, loff_t *ppos)
{
	char ch;
	size_t read = 0;
	ssize_t ret;

	if (!*ppos)
		trace_parser_clear(parser);

	ret = get_user(ch, ubuf++);
	if (ret)
		goto out;

	read++;
	cnt--;

	/*
	 * The parser is not finished with the last write,
	 * continue reading the user input without skipping spaces.
	 */
	if (!parser->cont) {
		/* skip white space */
		while (cnt && isspace(ch)) {
			ret = get_user(ch, ubuf++);
			if (ret)
				goto out;
			read++;
			cnt--;
		}

		/* only spaces were written */
		if (isspace(ch)) {
			*ppos += read;
			ret = read;
			goto out;
		}

		parser->idx = 0;
	}

	/* read the non-space input */
	while (cnt && !isspace(ch)) {
		if (parser->idx < parser->size - 1)
			parser->buffer[parser->idx++] = ch;
		else {
			ret = -EINVAL;
			goto out;
		}
		ret = get_user(ch, ubuf++);
		if (ret)
			goto out;
		read++;
		cnt--;
	}

	/* We either got finished input or we have to wait for another call. */
	if (isspace(ch)) {
		parser->buffer[parser->idx] = 0;
		parser->cont = false;
	} else {
		parser->cont = true;
		parser->buffer[parser->idx++] = ch;
	}

	*ppos += read;
	ret = read;

out:
	return ret;
}

ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf, size_t cnt)
{
	int len;
	int ret;

	if (!cnt)
		return 0;

	if (s->len <= s->readpos)
		return -EBUSY;

	len = s->len - s->readpos;
	if (cnt > len)
		cnt = len;
	ret = copy_to_user(ubuf, s->buffer + s->readpos, cnt);
	if (ret == cnt)
		return -EFAULT;

	cnt -= ret;

	s->readpos += cnt;
	return cnt;
}

static ssize_t trace_seq_to_buffer(struct trace_seq *s, void *buf, size_t cnt)
{
	int len;

	if (s->len <= s->readpos)
		return -EBUSY;

	len = s->len - s->readpos;
	if (cnt > len)
		cnt = len;
	memcpy(buf, s->buffer + s->readpos, cnt);

	s->readpos += cnt;
	return cnt;
}

/*
 * ftrace_max_lock is used to protect the swapping of buffers
 * when taking a max snapshot. The buffers themselves are
 * protected by per_cpu spinlocks. But the action of the swap
 * needs its own lock.
 *
 * This is defined as a arch_spinlock_t in order to help
 * with performance when lockdep debugging is enabled.
 *
 * It is also used in other places outside the update_max_tr
 * so it needs to be defined outside of the
 * CONFIG_TRACER_MAX_TRACE.
 */
static arch_spinlock_t ftrace_max_lock =
	(arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;

unsigned long __read_mostly	tracing_thresh;

#ifdef CONFIG_TRACER_MAX_TRACE
unsigned long __read_mostly	tracing_max_latency;

/*
 * Copy the new maximum trace into the separate maximum-trace
 * structure. (this way the maximum trace is permanently saved,
 * for later retrieval via /sys/kernel/debug/tracing/latency_trace)
 */
static void
__update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
{
	struct trace_buffer *trace_buf = &tr->trace_buffer;
	struct trace_buffer *max_buf = &tr->max_buffer;
	struct trace_array_cpu *data = per_cpu_ptr(trace_buf->data, cpu);
	struct trace_array_cpu *max_data = per_cpu_ptr(max_buf->data, cpu);

	max_buf->cpu = cpu;
	max_buf->time_start = data->preempt_timestamp;

	max_data->saved_latency = tracing_max_latency;
	max_data->critical_start = data->critical_start;
	max_data->critical_end = data->critical_end;

	memcpy(max_data->comm, tsk->comm, TASK_COMM_LEN);
	max_data->pid = tsk->pid;
	/*
	 * If tsk == current, then use current_uid(), as that does not use
	 * RCU. The irq tracer can be called out of RCU scope.
	 */
	if (tsk == current)
		max_data->uid = current_uid();
	else
		max_data->uid = task_uid(tsk);

	max_data->nice = tsk->static_prio - 20 - MAX_RT_PRIO;
	max_data->policy = tsk->policy;
	max_data->rt_priority = tsk->rt_priority;

	/* record this tasks comm */
	tracing_record_cmdline(tsk);
}

/**
 * update_max_tr - snapshot all trace buffers from global_trace to max_tr
 * @tr: tracer
 * @tsk: the task with the latency
 * @cpu: The cpu that initiated the trace.
 *
 * Flip the buffers between the @tr and the max_tr and record information
 * about which task was the cause of this latency.
 */
void
update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
{
	struct ring_buffer *buf;

	if (tr->stop_count)
		return;

	WARN_ON_ONCE(!irqs_disabled());

	if (!tr->allocated_snapshot) {
		/* Only the nop tracer should hit this when disabling */
		WARN_ON_ONCE(tr->current_trace != &nop_trace);
		return;
	}

	arch_spin_lock(&ftrace_max_lock);

	buf = tr->trace_buffer.buffer;
	tr->trace_buffer.buffer = tr->max_buffer.buffer;
	tr->max_buffer.buffer = buf;

	__update_max_tr(tr, tsk, cpu);
	arch_spin_unlock(&ftrace_max_lock);
}

/**
 * update_max_tr_single - only copy one trace over, and reset the rest
 * @tr - tracer
 * @tsk - task with the latency
 * @cpu - the cpu of the buffer to copy.
 *
 * Flip the trace of a single CPU buffer between the @tr and the max_tr.
 */
void
update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu)
{
	int ret;

	if (tr->stop_count)
		return;

	WARN_ON_ONCE(!irqs_disabled());
	if (!tr->allocated_snapshot) {
		/* Only the nop tracer should hit this when disabling */
		WARN_ON_ONCE(tr->current_trace != &nop_trace);
		return;
	}

	arch_spin_lock(&ftrace_max_lock);

	ret = ring_buffer_swap_cpu(tr->max_buffer.buffer, tr->trace_buffer.buffer, cpu);

	if (ret == -EBUSY) {
		/*
		 * We failed to swap the buffer due to a commit taking
		 * place on this CPU. We fail to record, but we reset
		 * the max trace buffer (no one writes directly to it)
		 * and flag that it failed.
		 */
		trace_array_printk_buf(tr->max_buffer.buffer, _THIS_IP_,
			"Failed to swap buffers due to commit in progress\n");
	}

	WARN_ON_ONCE(ret && ret != -EAGAIN && ret != -EBUSY);

	__update_max_tr(tr, tsk, cpu);
	arch_spin_unlock(&ftrace_max_lock);
}
#endif /* CONFIG_TRACER_MAX_TRACE */

static void default_wait_pipe(struct trace_iterator *iter)
{
	/* Iterators are static, they should be filled or empty */
	if (trace_buffer_iter(iter, iter->cpu_file))
		return;

	ring_buffer_wait(iter->trace_buffer->buffer, iter->cpu_file);
}

#ifdef CONFIG_FTRACE_STARTUP_TEST
static int run_tracer_selftest(struct tracer *type)
{
	struct trace_array *tr = &global_trace;
	struct tracer *saved_tracer = tr->current_trace;
	int ret;

	if (!type->selftest || tracing_selftest_disabled)
		return 0;

	/*
	 * Run a selftest on this tracer.
	 * Here we reset the trace buffer, and set the current
	 * tracer to be this tracer. The tracer can then run some
	 * internal tracing to verify that everything is in order.
	 * If we fail, we do not register this tracer.
	 */
	tracing_reset_online_cpus(&tr->trace_buffer);

	tr->current_trace = type;

#ifdef CONFIG_TRACER_MAX_TRACE
	if (type->use_max_tr) {
		/* If we expanded the buffers, make sure the max is expanded too */
		if (ring_buffer_expanded)
			ring_buffer_resize(tr->max_buffer.buffer, trace_buf_size,
					   RING_BUFFER_ALL_CPUS);
		tr->allocated_snapshot = true;
	}
#endif

	/* the test is responsible for initializing and enabling */
	pr_info("Testing tracer %s: ", type->name);
	ret = type->selftest(type, tr);
	/* the test is responsible for resetting too */
	tr->current_trace = saved_tracer;
	if (ret) {
		printk(KERN_CONT "FAILED!\n");
		/* Add the warning after printing 'FAILED' */
		WARN_ON(1);
		return -1;
	}
	/* Only reset on passing, to avoid touching corrupted buffers */
	tracing_reset_online_cpus(&tr->trace_buffer);

#ifdef CONFIG_TRACER_MAX_TRACE
	if (type->use_max_tr) {
		tr->allocated_snapshot = false;

		/* Shrink the max buffer again */
		if (ring_buffer_expanded)
			ring_buffer_resize(tr->max_buffer.buffer, 1,
					   RING_BUFFER_ALL_CPUS);
	}
#endif

	printk(KERN_CONT "PASSED\n");
	return 0;
}
#else
static inline int run_tracer_selftest(struct tracer *type)
{
	return 0;
}
#endif /* CONFIG_FTRACE_STARTUP_TEST */

/**
 * register_tracer - register a tracer with the ftrace system.
 * @type - the plugin for the tracer
 *
 * Register a new plugin tracer.
 */
int register_tracer(struct tracer *type)
{
	struct tracer *t;
	int ret = 0;

	if (!type->name) {
		pr_info("Tracer must have a name\n");
		return -1;
	}

	if (strlen(type->name) >= MAX_TRACER_SIZE) {
		pr_info("Tracer has a name longer than %d\n", MAX_TRACER_SIZE);
		return -1;
	}

	mutex_lock(&trace_types_lock);

	tracing_selftest_running = true;

	for (t = trace_types; t; t = t->next) {
		if (strcmp(type->name, t->name) == 0) {
			/* already found */
			pr_info("Tracer %s already registered\n",
				type->name);
			ret = -1;
			goto out;
		}
	}

	if (!type->set_flag)
		type->set_flag = &dummy_set_flag;
	if (!type->flags)
		type->flags = &dummy_tracer_flags;
	else
		if (!type->flags->opts)
			type->flags->opts = dummy_tracer_opt;
	if (!type->wait_pipe)
		type->wait_pipe = default_wait_pipe;

	ret = run_tracer_selftest(type);
	if (ret < 0)
		goto out;

	type->next = trace_types;
	trace_types = type;

 out:
	tracing_selftest_running = false;
	mutex_unlock(&trace_types_lock);

	if (ret || !default_bootup_tracer)
		goto out_unlock;

	if (strncmp(default_bootup_tracer, type->name, MAX_TRACER_SIZE))
		goto out_unlock;

	printk(KERN_INFO "Starting tracer '%s'\n", type->name);
	/* Do we want this tracer to start on bootup? */
	tracing_set_tracer(type->name);
	default_bootup_tracer = NULL;
	/* disable other selftests, since this will break it. */
	tracing_selftest_disabled = true;
#ifdef CONFIG_FTRACE_STARTUP_TEST
	printk(KERN_INFO "Disabling FTRACE selftests due to running tracer '%s'\n",
	       type->name);
#endif

 out_unlock:
	return ret;
}

void tracing_reset(struct trace_buffer *buf, int cpu)
{
	struct ring_buffer *buffer = buf->buffer;

	if (!buffer)
		return;

	ring_buffer_record_disable(buffer);

	/* Make sure all commits have finished */
	synchronize_sched();
	ring_buffer_reset_cpu(buffer, cpu);

	ring_buffer_record_enable(buffer);
}

void tracing_reset_online_cpus(struct trace_buffer *buf)
{
	struct ring_buffer *buffer = buf->buffer;
	int cpu;

	if (!buffer)
		return;

	ring_buffer_record_disable(buffer);

	/* Make sure all commits have finished */
	synchronize_sched();

	buf->time_start = buffer_ftrace_now(buf, buf->cpu);

	for_each_online_cpu(cpu)
		ring_buffer_reset_cpu(buffer, cpu);

	ring_buffer_record_enable(buffer);
}

/* Must have trace_types_lock held */
void tracing_reset_all_online_cpus(void)
{
	struct trace_array *tr;

	list_for_each_entry(tr, &ftrace_trace_arrays, list) {
		tracing_reset_online_cpus(&tr->trace_buffer);
#ifdef CONFIG_TRACER_MAX_TRACE
		tracing_reset_online_cpus(&tr->max_buffer);
#endif
	}
}

#define SAVED_CMDLINES 128
#define NO_CMDLINE_MAP UINT_MAX
static unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1];
static unsigned map_cmdline_to_pid[SAVED_CMDLINES];
static char saved_cmdlines[SAVED_CMDLINES][TASK_COMM_LEN];
static int cmdline_idx;
static arch_spinlock_t trace_cmdline_lock = __ARCH_SPIN_LOCK_UNLOCKED;

/* temporary disable recording */
static atomic_t trace_record_cmdline_disabled __read_mostly;

static void trace_init_cmdlines(void)
{
	memset(&map_pid_to_cmdline, NO_CMDLINE_MAP, sizeof(map_pid_to_cmdline));
	memset(&map_cmdline_to_pid, NO_CMDLINE_MAP, sizeof(map_cmdline_to_pid));
	cmdline_idx = 0;
}

int is_tracing_stopped(void)
{
	return global_trace.stop_count;
}

/**
 * ftrace_off_permanent - disable all ftrace code permanently
 *
 * This should only be called when a serious anomally has
 * been detected.  This will turn off the function tracing,
 * ring buffers, and other tracing utilites. It takes no
 * locks and can be called from any context.
 */
void ftrace_off_permanent(void)
{
	tracing_disabled = 1;
	ftrace_stop();
	tracing_off_permanent();
}

/**
 * tracing_start - quick start of the tracer
 *
 * If tracing is enabled but was stopped by tracing_stop,
 * this will start the tracer back up.
 */
void tracing_start(void)
{
	struct ring_buffer *buffer;
	unsigned long flags;

	if (tracing_disabled)
		return;

	raw_spin_lock_irqsave(&global_trace.start_lock, flags);
	if (--global_trace.stop_count) {
		if (global_trace.stop_count < 0) {
			/* Someone screwed up their debugging */
			WARN_ON_ONCE(1);
			global_trace.stop_count = 0;
		}
		goto out;
	}

	/* Prevent the buffers from switching */
	arch_spin_lock(&ftrace_max_lock);

	buffer = global_trace.trace_buffer.buffer;
	if (buffer)
		ring_buffer_record_enable(buffer);

#ifdef CONFIG_TRACER_MAX_TRACE
	buffer = global_trace.max_buffer.buffer;
	if (buffer)
		ring_buffer_record_enable(buffer);
#endif

	arch_spin_unlock(&ftrace_max_lock);

	ftrace_start();
 out:
	raw_spin_unlock_irqrestore(&global_trace.start_lock, flags);
}

static void tracing_start_tr(struct trace_array *tr)
{
	struct ring_buffer *buffer;
	unsigned long flags;

	if (tracing_disabled)
		return;

	/* If global, we need to also start the max tracer */
	if (tr->flags & TRACE_ARRAY_FL_GLOBAL)
		return tracing_start();

	raw_spin_lock_irqsave(&tr->start_lock, flags);

	if (--tr->stop_count) {
		if (tr->stop_count < 0) {
			/* Someone screwed up their debugging */
			WARN_ON_ONCE(1);
			tr->stop_count = 0;
		}
		goto out;
	}

	buffer = tr->trace_buffer.buffer;
	if (buffer)
		ring_buffer_record_enable(buffer);

 out:
	raw_spin_unlock_irqrestore(&tr->start_lock, flags);
}

/**
 * tracing_stop - quick stop of the tracer
 *
 * Light weight way to stop tracing. Use in conjunction with
 * tracing_start.
 */
void tracing_stop(void)
{
	struct ring_buffer *buffer;
	unsigned long flags;

	ftrace_stop();
	raw_spin_lock_irqsave(&global_trace.start_lock, flags);
	if (global_trace.stop_count++)
		goto out;

	/* Prevent the buffers from switching */
	arch_spin_lock(&ftrace_max_lock);

	buffer = global_trace.trace_buffer.buffer;
	if (buffer)
		ring_buffer_record_disable(buffer);

#ifdef CONFIG_TRACER_MAX_TRACE
	buffer = global_trace.max_buffer.buffer;
	if (buffer)
		ring_buffer_record_disable(buffer);
#endif

	arch_spin_unlock(&ftrace_max_lock);

 out:
	raw_spin_unlock_irqrestore(&global_trace.start_lock, flags);
}

static void tracing_stop_tr(struct trace_array *tr)
{
	struct ring_buffer *buffer;
	unsigned long flags;

	/* If global, we need to also stop the max tracer */
	if (tr->flags & TRACE_ARRAY_FL_GLOBAL)
		return tracing_stop();

	raw_spin_lock_irqsave(&tr->start_lock, flags);
	if (tr->stop_count++)
		goto out;

	buffer = tr->trace_buffer.buffer;
	if (buffer)
		ring_buffer_record_disable(buffer);

 out:
	raw_spin_unlock_irqrestore(&tr->start_lock, flags);
}

void trace_stop_cmdline_recording(void);

static void trace_save_cmdline(struct task_struct *tsk)
{
	unsigned pid, idx;

	if (!tsk->pid || unlikely(tsk->pid > PID_MAX_DEFAULT))
		return;

	/*
	 * It's not the end of the world if we don't get
	 * the lock, but we also don't want to spin
	 * nor do we want to disable interrupts,
	 * so if we miss here, then better luck next time.
	 */
	if (!arch_spin_trylock(&trace_cmdline_lock))
		return;

	idx = map_pid_to_cmdline[tsk->pid];
	if (idx == NO_CMDLINE_MAP) {
		idx = (cmdline_idx + 1) % SAVED_CMDLINES;

		/*
		 * Check whether the cmdline buffer at idx has a pid
		 * mapped. We are going to overwrite that entry so we
		 * need to clear the map_pid_to_cmdline. Otherwise we
		 * would read the new comm for the old pid.
		 */
		pid = map_cmdline_to_pid[idx];
		if (pid != NO_CMDLINE_MAP)
			map_pid_to_cmdline[pid] = NO_CMDLINE_MAP;

		map_cmdline_to_pid[idx] = tsk->pid;
		map_pid_to_cmdline[tsk->pid] = idx;

		cmdline_idx = idx;
	}

	memcpy(&saved_cmdlines[idx], tsk->comm, TASK_COMM_LEN);

	arch_spin_unlock(&trace_cmdline_lock);
}

void trace_find_cmdline(int pid, char comm[])
{
	unsigned map;

	if (!pid) {
		strcpy(comm, "<idle>");
		return;
	}

	if (WARN_ON_ONCE(pid < 0)) {
		strcpy(comm, "<XXX>");
		return;
	}

	if (pid > PID_MAX_DEFAULT) {
		strcpy(comm, "<...>");
		return;
	}

	preempt_disable();
	arch_spin_lock(&trace_cmdline_lock);
	map = map_pid_to_cmdline[pid];
	if (map != NO_CMDLINE_MAP)
		strcpy(comm, saved_cmdlines[map]);
	else
		strcpy(comm, "<...>");

	arch_spin_unlock(&trace_cmdline_lock);
	preempt_enable();
}

void tracing_record_cmdline(struct task_struct *tsk)
{
	if (atomic_read(&trace_record_cmdline_disabled) || !tracing_is_on())
		return;

	if (!__this_cpu_read(trace_cmdline_save))
		return;

	__this_cpu_write(trace_cmdline_save, false);

	trace_save_cmdline(tsk);
}

void
tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags,
			     int pc)
{
	struct task_struct *tsk = current;

	entry->preempt_count		= pc & 0xff;
	entry->pid			= (tsk) ? tsk->pid : 0;
	entry->flags =
#ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT
		(irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) |
#else
		TRACE_FLAG_IRQS_NOSUPPORT |
#endif
		((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) |
		((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) |
		(need_resched() ? TRACE_FLAG_NEED_RESCHED : 0);
}
EXPORT_SYMBOL_GPL(tracing_generic_entry_update);

struct ring_buffer_event *
trace_buffer_lock_reserve(struct ring_buffer *buffer,
			  int type,
			  unsigned long len,
			  unsigned long flags, int pc)
{
	struct ring_buffer_event *event;

	event = ring_buffer_lock_reserve(buffer, len);
	if (event != NULL) {
		struct trace_entry *ent = ring_buffer_event_data(event);

		tracing_generic_entry_update(ent, flags, pc);
		ent->type = type;
	}

	return event;
}

void
__buffer_unlock_commit(struct ring_buffer *buffer, struct ring_buffer_event *event)
{
	__this_cpu_write(trace_cmdline_save, true);
	ring_buffer_unlock_commit(buffer, event);
}

static inline void
__trace_buffer_unlock_commit(struct ring_buffer *buffer,
			     struct ring_buffer_event *event,
			     unsigned long flags, int pc)
{
	__buffer_unlock_commit(buffer, event);

	ftrace_trace_stack(buffer, flags, 6, pc);
	ftrace_trace_userstack(buffer, flags, pc);
}

void trace_buffer_unlock_commit(struct ring_buffer *buffer,
				struct ring_buffer_event *event,
				unsigned long flags, int pc)
{
	__trace_buffer_unlock_commit(buffer, event, flags, pc);
}
EXPORT_SYMBOL_GPL(trace_buffer_unlock_commit);

struct ring_buffer_event *
trace_event_buffer_lock_reserve(struct ring_buffer **current_rb,
			  struct ftrace_event_file *ftrace_file,
			  int type, unsigned long len,
			  unsigned long flags, int pc)
{
	*current_rb = ftrace_file->tr->trace_buffer.buffer;
	return trace_buffer_lock_reserve(*current_rb,
					 type, len, flags, pc);
}
EXPORT_SYMBOL_GPL(trace_event_buffer_lock_reserve);

struct ring_buffer_event *
trace_current_buffer_lock_reserve(struct ring_buffer **current_rb,
				  int type, unsigned long len,
				  unsigned long flags, int pc)
{
	*current_rb = global_trace.trace_buffer.buffer;
	return trace_buffer_lock_reserve(*current_rb,
					 type, len, flags, pc);
}
EXPORT_SYMBOL_GPL(trace_current_buffer_lock_reserve);

void trace_current_buffer_unlock_commit(struct ring_buffer *buffer,
					struct ring_buffer_event *event,
					unsigned long flags, int pc)
{
	__trace_buffer_unlock_commit(buffer, event, flags, pc);
}
EXPORT_SYMBOL_GPL(trace_current_buffer_unlock_commit);

void trace_buffer_unlock_commit_regs(struct ring_buffer *buffer,
				     struct ring_buffer_event *event,
				     unsigned long flags, int pc,
				     struct pt_regs *regs)
{
	__buffer_unlock_commit(buffer, event);

	ftrace_trace_stack_regs(buffer, flags, 0, pc, regs);
	ftrace_trace_userstack(buffer, flags, pc);
}
EXPORT_SYMBOL_GPL(trace_buffer_unlock_commit_regs);

void trace_current_buffer_discard_commit(struct ring_buffer *buffer,
					 struct ring_buffer_event *event)
{
	ring_buffer_discard_commit(buffer, event);
}
EXPORT_SYMBOL_GPL(trace_current_buffer_discard_commit);

void
trace_function(struct trace_array *tr,
	       unsigned long ip, unsigned long parent_ip, unsigned long flags,
	       int pc)
{
	struct ftrace_event_call *call = &event_function;
	struct ring_buffer *buffer = tr->trace_buffer.buffer;
	struct ring_buffer_event *event;
	struct ftrace_entry *entry;

	/* If we are reading the ring buffer, don't trace */
	if (unlikely(__this_cpu_read(ftrace_cpu_disabled)))
		return;

	event = trace_buffer_lock_reserve(buffer, TRACE_FN, sizeof(*entry),
					  flags, pc);
	if (!event)
		return;
	entry	= ring_buffer_event_data(event);
	entry->ip			= ip;
	entry->parent_ip		= parent_ip;

	if (!filter_check_discard(call, entry, buffer, event))
		__buffer_unlock_commit(buffer, event);
}

void
ftrace(struct trace_array *tr, struct trace_array_cpu *data,
       unsigned long ip, unsigned long parent_ip, unsigned long flags,
       int pc)
{
	if (likely(!atomic_read(&data->disabled)))
		trace_function(tr, ip, parent_ip, flags, pc);
}

#ifdef CONFIG_STACKTRACE

#define FTRACE_STACK_MAX_ENTRIES (PAGE_SIZE / sizeof(unsigned long))
struct ftrace_stack {
	unsigned long		calls[FTRACE_STACK_MAX_ENTRIES];
};

static DEFINE_PER_CPU(struct ftrace_stack, ftrace_stack);
static DEFINE_PER_CPU(int, ftrace_stack_reserve);

static void __ftrace_trace_stack(struct ring_buffer *buffer,
				 unsigned long flags,
				 int skip, int pc, struct pt_regs *regs)
{
	struct ftrace_event_call *call = &event_kernel_stack;
	struct ring_buffer_event *event;
	struct stack_entry *entry;
	struct stack_trace trace;
	int use_stack;
	int size = FTRACE_STACK_ENTRIES;

	trace.nr_entries	= 0;
	trace.skip		= skip;

	/*
	 * Since events can happen in NMIs there's no safe way to
	 * use the per cpu ftrace_stacks. We reserve it and if an interrupt
	 * or NMI comes in, it will just have to use the default
	 * FTRACE_STACK_SIZE.
	 */
	preempt_disable_notrace();

	use_stack = __this_cpu_inc_return(ftrace_stack_reserve);
	/*
	 * We don't need any atomic variables, just a barrier.
	 * If an interrupt comes in, we don't care, because it would
	 * have exited and put the counter back to what we want.
	 * We just need a barrier to keep gcc from moving things
	 * around.
	 */
	barrier();
	if (use_stack == 1) {
		trace.entries		= &__get_cpu_var(ftrace_stack).calls[0];
		trace.max_entries	= FTRACE_STACK_MAX_ENTRIES;

		if (regs)
			save_stack_trace_regs(regs, &trace);
		else
			save_stack_trace(&trace);

		if (trace.nr_entries > size)
			size = trace.nr_entries;
	} else
		/* From now on, use_stack is a boolean */
		use_stack = 0;

	size *= sizeof(unsigned long);

	event = trace_buffer_lock_reserve(buffer, TRACE_STACK,
					  sizeof(*entry) + size, flags, pc);
	if (!event)
		goto out;
	entry = ring_buffer_event_data(event);

	memset(&entry->caller, 0, size);

	if (use_stack)
		memcpy(&entry->caller, trace.entries,
		       trace.nr_entries * sizeof(unsigned long));
	else {
		trace.max_entries	= FTRACE_STACK_ENTRIES;
		trace.entries		= entry->caller;
		if (regs)
			save_stack_trace_regs(regs, &trace);
		else
			save_stack_trace(&trace);
	}

	entry->size = trace.nr_entries;

	if (!filter_check_discard(call, entry, buffer, event))
		__buffer_unlock_commit(buffer, event);

 out:
	/* Again, don't let gcc optimize things here */
	barrier();
	__this_cpu_dec(ftrace_stack_reserve);
	preempt_enable_notrace();

}

void ftrace_trace_stack_regs(struct ring_buffer *buffer, unsigned long flags,
			     int skip, int pc, struct pt_regs *regs)
{
	if (!(trace_flags & TRACE_ITER_STACKTRACE))
		return;

	__ftrace_trace_stack(buffer, flags, skip, pc, regs);
}

void ftrace_trace_stack(struct ring_buffer *buffer, unsigned long flags,
			int skip, int pc)
{
	if (!(trace_flags & TRACE_ITER_STACKTRACE))
		return;

	__ftrace_trace_stack(buffer, flags, skip, pc, NULL);
}

void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
		   int pc)
{
	__ftrace_trace_stack(tr->trace_buffer.buffer, flags, skip, pc, NULL);
}

/**
 * trace_dump_stack - record a stack back trace in the trace buffer
 * @skip: Number of functions to skip (helper handlers)
 */
void trace_dump_stack(int skip)
{
	unsigned long flags;

	if (tracing_disabled || tracing_selftest_running)
		return;

	local_save_flags(flags);

	/*
	 * Skip 3 more, seems to get us at the caller of
	 * this function.
	 */
	skip += 3;
	__ftrace_trace_stack(global_trace.trace_buffer.buffer,
			     flags, skip, preempt_count(), NULL);
}

static DEFINE_PER_CPU(int, user_stack_count);

void
ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc)
{
	struct ftrace_event_call *call = &event_user_stack;
	struct ring_buffer_event *event;
	struct userstack_entry *entry;
	struct stack_trace trace;

	if (!(trace_flags & TRACE_ITER_USERSTACKTRACE))
		return;

	/*
	 * NMIs can not handle page faults, even with fix ups.
	 * The save user stack can (and often does) fault.
	 */
	if (unlikely(in_nmi()))
		return;

	/*
	 * prevent recursion, since the user stack tracing may
	 * trigger other kernel events.
	 */
	preempt_disable();
	if (__this_cpu_read(user_stack_count))
		goto out;

	__this_cpu_inc(user_stack_count);

	event = trace_buffer_lock_reserve(buffer, TRACE_USER_STACK,
					  sizeof(*entry), flags, pc);
	if (!event)
		goto out_drop_count;
	entry	= ring_buffer_event_data(event);

	entry->tgid		= current->tgid;
	memset(&entry->caller, 0, sizeof(entry->caller));

	trace.nr_entries	= 0;
	trace.max_entries	= FTRACE_STACK_ENTRIES;
	trace.skip		= 0;
	trace.entries		= entry->caller;

	save_stack_trace_user(&trace);
	if (!filter_check_discard(call, entry, buffer, event))
		__buffer_unlock_commit(buffer, event);

 out_drop_count:
	__this_cpu_dec(user_stack_count);
 out:
	preempt_enable();
}

#ifdef UNUSED
static void __trace_userstack(struct trace_array *tr, unsigned long flags)
{
	ftrace_trace_userstack(tr, flags, preempt_count());
}
#endif /* UNUSED */

#endif /* CONFIG_STACKTRACE */

/* created for use with alloc_percpu */
struct trace_buffer_struct {
	char buffer[TRACE_BUF_SIZE];
};

static struct trace_buffer_struct *trace_percpu_buffer;
static struct trace_buffer_struct *trace_percpu_sirq_buffer;
static struct trace_buffer_struct *trace_percpu_irq_buffer;
static struct trace_buffer_struct *trace_percpu_nmi_buffer;

/*
 * The buffer used is dependent on the context. There is a per cpu
 * buffer for normal context, softirq contex, hard irq context and
 * for NMI context. Thise allows for lockless recording.
 *
 * Note, if the buffers failed to be allocated, then this returns NULL
 */
static char *get_trace_buf(void)
{
	struct trace_buffer_struct *percpu_buffer;

	/*
	 * If we have allocated per cpu buffers, then we do not
	 * need to do any locking.
	 */
	if (in_nmi())
		percpu_buffer = trace_percpu_nmi_buffer;
	else if (in_irq())
		percpu_buffer = trace_percpu_irq_buffer;
	else if (in_softirq())
		percpu_buffer = trace_percpu_sirq_buffer;
	else
		percpu_buffer = trace_percpu_buffer;

	if (!percpu_buffer)
		return NULL;

	return this_cpu_ptr(&percpu_buffer->buffer[0]);
}

static int alloc_percpu_trace_buffer(void)
{
	struct trace_buffer_struct *buffers;
	struct trace_buffer_struct *sirq_buffers;
	struct trace_buffer_struct *irq_buffers;
	struct trace_buffer_struct *nmi_buffers;

	buffers = alloc_percpu(struct trace_buffer_struct);
	if (!buffers)
		goto err_warn;

	sirq_buffers = alloc_percpu(struct trace_buffer_struct);
	if (!sirq_buffers)
		goto err_sirq;

	irq_buffers = alloc_percpu(struct trace_buffer_struct);
	if (!irq_buffers)
		goto err_irq;

	nmi_buffers = alloc_percpu(struct trace_buffer_struct);
	if (!nmi_buffers)
		goto err_nmi;

	trace_percpu_buffer = buffers;
	trace_percpu_sirq_buffer = sirq_buffers;
	trace_percpu_irq_buffer = irq_buffers;
	trace_percpu_nmi_buffer = nmi_buffers;

	return 0;

 err_nmi:
	free_percpu(irq_buffers);
 err_irq:
	free_percpu(sirq_buffers);
 err_sirq:
	free_percpu(buffers);
 err_warn:
	WARN(1, "Could not allocate percpu trace_printk buffer");
	return -ENOMEM;
}

static int buffers_allocated;

void trace_printk_init_buffers(void)
{
	if (buffers_allocated)
		return;

	if (alloc_percpu_trace_buffer())
		return;

	pr_info("ftrace: Allocated trace_printk buffers\n");

	/* Expand the buffers to set size */
	tracing_update_buffers();

	buffers_allocated = 1;

	/*
	 * trace_printk_init_buffers() can be called by modules.
	 * If that happens, then we need to start cmdline recording
	 * directly here. If the global_trace.buffer is already
	 * allocated here, then this was called by module code.
	 */
	if (global_trace.trace_buffer.buffer)
		tracing_start_cmdline_record();
}

void trace_printk_start_comm(void)
{
	/* Start tracing comms if trace printk is set */
	if (!buffers_allocated)
		return;
	tracing_start_cmdline_record();
}

static void trace_printk_start_stop_comm(int enabled)
{
	if (!buffers_allocated)
		return;

	if (enabled)
		tracing_start_cmdline_record();
	else
		tracing_stop_cmdline_record();
}

/**
 * trace_vbprintk - write binary msg to tracing buffer
 *
 */
int trace_vbprintk(unsigned long ip, const char *fmt, va_list args)
{
	struct ftrace_event_call *call = &event_bprint;
	struct ring_buffer_event *event;
	struct ring_buffer *buffer;
	struct trace_array *tr = &global_trace;
	struct bprint_entry *entry;
	unsigned long flags;
	char *tbuffer;
	int len = 0, size, pc;

	if (unlikely(tracing_selftest_running || tracing_disabled))
		return 0;

	/* Don't pollute graph traces with trace_vprintk internals */
	pause_graph_tracing();

	pc = preempt_count();
	preempt_disable_notrace();

	tbuffer = get_trace_buf();
	if (!tbuffer) {
		len = 0;
		goto out;
	}

	len = vbin_printf((u32 *)tbuffer, TRACE_BUF_SIZE/sizeof(int), fmt, args);

	if (len > TRACE_BUF_SIZE/sizeof(int) || len < 0)
		goto out;

	local_save_flags(flags);
	size = sizeof(*entry) + sizeof(u32) * len;
	buffer = tr->trace_buffer.buffer;
	event = trace_buffer_lock_reserve(buffer, TRACE_BPRINT, size,
					  flags, pc);
	if (!event)
		goto out;
	entry = ring_buffer_event_data(event);
	entry->ip			= ip;
	entry->fmt			= fmt;

	memcpy(entry->buf, tbuffer, sizeof(u32) * len);
	if (!filter_check_discard(call, entry, buffer, event)) {
		__buffer_unlock_commit(buffer, event);
		ftrace_trace_stack(buffer, flags, 6, pc);
	}

out:
	preempt_enable_notrace();
	unpause_graph_tracing();

	return len;
}
EXPORT_SYMBOL_GPL(trace_vbprintk);

static int
__trace_array_vprintk(struct ring_buffer *buffer,
		      unsigned long ip, const char *fmt, va_list args)
{
	struct ftrace_event_call *call = &event_print;
	struct ring_buffer_event *event;
	int len = 0, size, pc;
	struct print_entry *entry;
	unsigned long flags;
	char *tbuffer;

	if (tracing_disabled || tracing_selftest_running)
		return 0;

	/* Don't pollute graph traces with trace_vprintk internals */
	pause_graph_tracing();

	pc = preempt_count();
	preempt_disable_notrace();


	tbuffer = get_trace_buf();
	if (!tbuffer) {
		len = 0;
		goto out;
	}

	len = vsnprintf(tbuffer, TRACE_BUF_SIZE, fmt, args);
	if (len > TRACE_BUF_SIZE)
		goto out;

	local_save_flags(flags);
	size = sizeof(*entry) + len + 1;
	event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, size,
					  flags, pc);
	if (!event)
		goto out;
	entry = ring_buffer_event_data(event);
	entry->ip = ip;

	memcpy(&entry->buf, tbuffer, len);
	entry->buf[len] = '\0';
	if (!filter_check_discard(call, entry, buffer, event)) {
		__buffer_unlock_commit(buffer, event);
		ftrace_trace_stack(buffer, flags, 6, pc);
	}
 out:
	preempt_enable_notrace();
	unpause_graph_tracing();

	return len;
}

int trace_array_vprintk(struct trace_array *tr,
			unsigned long ip, const char *fmt, va_list args)
{
	return __trace_array_vprintk(tr->trace_buffer.buffer, ip, fmt, args);
}

int trace_array_printk(struct trace_array *tr,
		       unsigned long ip, const char *fmt, ...)
{
	int ret;
	va_list ap;

	if (!(trace_flags & TRACE_ITER_PRINTK))
		return 0;

	va_start(ap, fmt);
	ret = trace_array_vprintk(tr, ip, fmt, ap);
	va_end(ap);
	return ret;
}

int trace_array_printk_buf(struct ring_buffer *buffer,
			   unsigned long ip, const char *fmt, ...)
{
	int ret;
	va_list ap;

	if (!(trace_flags & TRACE_ITER_PRINTK))
		return 0;

	va_start(ap, fmt);
	ret = __trace_array_vprintk(buffer, ip, fmt, ap);
	va_end(ap);
	return ret;
}

int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
{
	return trace_array_vprintk(&global_trace, ip, fmt, args);
}
EXPORT_SYMBOL_GPL(trace_vprintk);

static void trace_iterator_increment(struct trace_iterator *iter)
{
	struct ring_buffer_iter *buf_iter = trace_buffer_iter(iter, iter->cpu);

	iter->idx++;
	if (buf_iter)
		ring_buffer_read(buf_iter, NULL);
}

static struct trace_entry *
peek_next_entry(struct trace_iterator *iter, int cpu, u64 *ts,
		unsigned long *lost_events)
{
	struct ring_buffer_event *event;
	struct ring_buffer_iter *buf_iter = trace_buffer_iter(iter, cpu);

	if (buf_iter)
		event = ring_buffer_iter_peek(buf_iter, ts);
	else
		event = ring_buffer_peek(iter->trace_buffer->buffer, cpu, ts,
					 lost_events);

	if (event) {
		iter->ent_size = ring_buffer_event_length(event);
		return ring_buffer_event_data(event);
	}
	iter->ent_size = 0;
	return NULL;
}

static struct trace_entry *
__find_next_entry(struct trace_iterator *iter, int *ent_cpu,
		  unsigned long *missing_events, u64 *ent_ts)
{
	struct ring_buffer *buffer = iter->trace_buffer->buffer;
	struct trace_entry *ent, *next = NULL;
	unsigned long lost_events = 0, next_lost = 0;
	int cpu_file = iter->cpu_file;
	u64 next_ts = 0, ts;
	int next_cpu = -1;
	int next_size = 0;
	int cpu;

	/*
	 * If we are in a per_cpu trace file, don't bother by iterating over
	 * all cpu and peek directly.
	 */
	if (cpu_file > RING_BUFFER_ALL_CPUS) {
		if (ring_buffer_empty_cpu(buffer, cpu_file))
			return NULL;
		ent = peek_next_entry(iter, cpu_file, ent_ts, missing_events);
		if (ent_cpu)
			*ent_cpu = cpu_file;

		return ent;
	}

	for_each_tracing_cpu(cpu) {

		if (ring_buffer_empty_cpu(buffer, cpu))
			continue;

		ent = peek_next_entry(iter, cpu, &ts, &lost_events);

		/*
		 * Pick the entry with the smallest timestamp:
		 */
		if (ent && (!next || ts < next_ts)) {
			next = ent;
			next_cpu = cpu;
			next_ts = ts;
			next_lost = lost_events;
			next_size = iter->ent_size;
		}
	}

	iter->ent_size = next_size;

	if (ent_cpu)
		*ent_cpu = next_cpu;

	if (ent_ts)
		*ent_ts = next_ts;

	if (missing_events)
		*missing_events = next_lost;

	return next;
}

/* Find the next real entry, without updating the iterator itself */
struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
					  int *ent_cpu, u64 *ent_ts)
{
	return __find_next_entry(iter, ent_cpu, NULL, ent_ts);
}

/* Find the next real entry, and increment the iterator to the next entry */
void *trace_find_next_entry_inc(struct trace_iterator *iter)
{
	iter->ent = __find_next_entry(iter, &iter->cpu,
				      &iter->lost_events, &iter->ts);

	if (iter->ent)
		trace_iterator_increment(iter);

	return iter->ent ? iter : NULL;
}

static void trace_consume(struct trace_iterator *iter)
{
	ring_buffer_consume(iter->trace_buffer->buffer, iter->cpu, &iter->ts,
			    &iter->lost_events);
}

static void *s_next(struct seq_file *m, void *v, loff_t *pos)
{
	struct trace_iterator *iter = m->private;
	int i = (int)*pos;
	void *ent;

	WARN_ON_ONCE(iter->leftover);

	(*pos)++;

	/* can't go backwards */
	if (iter->idx > i)
		return NULL;

	if (iter->idx < 0)
		ent = trace_find_next_entry_inc(iter);
	else
		ent = iter;

	while (ent && iter->idx < i)
		ent = trace_find_next_entry_inc(iter);

	iter->pos = *pos;

	return ent;
}

void tracing_iter_reset(struct trace_iterator *iter, int cpu)
{
	struct ring_buffer_event *event;
	struct ring_buffer_iter *buf_iter;
	unsigned long entries = 0;
	u64 ts;

	per_cpu_ptr(iter->trace_buffer->data, cpu)->skipped_entries = 0;

	buf_iter = trace_buffer_iter(iter, cpu);
	if (!buf_iter)
		return;

	ring_buffer_iter_reset(buf_iter);

	/*
	 * We could have the case with the max latency tracers
	 * that a reset never took place on a cpu. This is evident
	 * by the timestamp being before the start of the buffer.
	 */
	while ((event = ring_buffer_iter_peek(buf_iter, &ts))) {
		if (ts >= iter->trace_buffer->time_start)
			break;
		entries++;
		ring_buffer_read(buf_iter, NULL);
	}

	per_cpu_ptr(iter->trace_buffer->data, cpu)->skipped_entries = entries;
}

/*
 * The current tracer is copied to avoid a global locking
 * all around.
 */
static void *s_start(struct seq_file *m, loff_t *pos)
{
	struct trace_iterator *iter = m->private;
	struct trace_array *tr = iter->tr;
	int cpu_file = iter->cpu_file;
	void *p = NULL;
	loff_t l = 0;
	int cpu;

	/*
	 * copy the tracer to avoid using a global lock all around.
	 * iter->trace is a copy of current_trace, the pointer to the
	 * name may be used instead of a strcmp(), as iter->trace->name
	 * will point to the same string as current_trace->name.
	 */
	mutex_lock(&trace_types_lock);
	if (unlikely(tr->current_trace && iter->trace->name != tr->current_trace->name))
		*iter->trace = *tr->current_trace;
	mutex_unlock(&trace_types_lock);

#ifdef CONFIG_TRACER_MAX_TRACE
	if (iter->snapshot && iter->trace->use_max_tr)
		return ERR_PTR(-EBUSY);
#endif

	if (!iter->snapshot)
		atomic_inc(&trace_record_cmdline_disabled);

	if (*pos != iter->pos) {
		iter->ent = NULL;
		iter->cpu = 0;
		iter->idx = -1;

		if (cpu_file == RING_BUFFER_ALL_CPUS) {
			for_each_tracing_cpu(cpu)
				tracing_iter_reset(iter, cpu);
		} else
			tracing_iter_reset(iter, cpu_file);

		iter->leftover = 0;
		for (p = iter; p && l < *pos; p = s_next(m, p, &l))
			;

	} else {
		/*
		 * If we overflowed the seq_file before, then we want
		 * to just reuse the trace_seq buffer again.
		 */
		if (iter->leftover)
			p = iter;
		else {
			l = *pos - 1;
			p = s_next(m, p, &l);
		}
	}

	trace_event_read_lock();
	trace_access_lock(cpu_file);
	return p;
}

static void s_stop(struct seq_file *m, void *p)
{
	struct trace_iterator *iter = m->private;

#ifdef CONFIG_TRACER_MAX_TRACE
	if (iter->snapshot && iter->trace->use_max_tr)
		return;
#endif

	if (!iter->snapshot)
		atomic_dec(&trace_record_cmdline_disabled);

	trace_access_unlock(iter->cpu_file);
	trace_event_read_unlock();
}

static void
get_total_entries(struct trace_buffer *buf,
		  unsigned long *total, unsigned long *entries)
{
	unsigned long count;
	int cpu;

	*total = 0;
	*entries = 0;

	for_each_tracing_cpu(cpu) {
		count = ring_buffer_entries_cpu(buf->buffer, cpu);
		/*
		 * If this buffer has skipped entries, then we hold all
		 * entries for the trace and we need to ignore the
		 * ones before the time stamp.
		 */
		if (per_cpu_ptr(buf->data, cpu)->skipped_entries) {
			count -= per_cpu_ptr(buf->data, cpu)->skipped_entries;
			/* total is the same as the entries */
			*total += count;
		} else
			*total += count +
				ring_buffer_overrun_cpu(buf->buffer, cpu);
		*entries += count;
	}
}

static void print_lat_help_header(struct seq_file *m)
{
	seq_puts(m, "#                  _------=> CPU#            \n");
	seq_puts(m, "#                 / _-----=> irqs-off        \n");
	seq_puts(m, "#                | / _----=> need-resched    \n");
	seq_puts(m, "#                || / _---=> hardirq/softirq \n");
	seq_puts(m, "#                ||| / _--=> preempt-depth   \n");
	seq_puts(m, "#                |||| /     delay             \n");
	seq_puts(m, "#  cmd     pid   ||||| time  |   caller      \n");
	seq_puts(m, "#     \\   /      |||||  \\    |   /           \n");
}

static void print_event_info(struct trace_buffer *buf, struct seq_file *m)
{
	unsigned long total;
	unsigned long entries;

	get_total_entries(buf, &total, &entries);
	seq_printf(m, "# entries-in-buffer/entries-written: %lu/%lu   #P:%d\n",
		   entries, total, num_online_cpus());
	seq_puts(m, "#\n");
}

static void print_func_help_header(struct trace_buffer *buf, struct seq_file *m)
{
	print_event_info(buf, m);
	seq_puts(m, "#           TASK-PID   CPU#      TIMESTAMP  FUNCTION\n");
	seq_puts(m, "#              | |       |          |         |\n");
}

static void print_func_help_header_irq(struct trace_buffer *buf, struct seq_file *m)
{
	print_event_info(buf, m);
	seq_puts(m, "#                              _-----=> irqs-off\n");
	seq_puts(m, "#                             / _----=> need-resched\n");
	seq_puts(m, "#                            | / _---=> hardirq/softirq\n");
	seq_puts(m, "#                            || / _--=> preempt-depth\n");
	seq_puts(m, "#                            ||| /     delay\n");
	seq_puts(m, "#           TASK-PID   CPU#  ||||    TIMESTAMP  FUNCTION\n");
	seq_puts(m, "#              | |       |   ||||       |         |\n");
}

void
print_trace_header(struct seq_file *m, struct trace_iterator *iter)
{
	unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
	struct trace_buffer *buf = iter->trace_buffer;
	struct trace_array_cpu *data = per_cpu_ptr(buf->data, buf->cpu);
	struct tracer *type = iter->trace;
	unsigned long entries;
	unsigned long total;
	const char *name = "preemption";

	name = type->name;

	get_total_entries(buf, &total, &entries);

	seq_printf(m, "# %s latency trace v1.1.5 on %s\n",
		   name, UTS_RELEASE);
	seq_puts(m, "# -----------------------------------"
		 "---------------------------------\n");
	seq_printf(m, "# latency: %lu us, #%lu/%lu, CPU#%d |"
		   " (M:%s VP:%d, KP:%d, SP:%d HP:%d",
		   nsecs_to_usecs(data->saved_latency),
		   entries,
		   total,
		   buf->cpu,
#if defined(CONFIG_PREEMPT_NONE)
		   "server",
#elif defined(CONFIG_PREEMPT_VOLUNTARY)
		   "desktop",
#elif defined(CONFIG_PREEMPT)
		   "preempt",
#else
		   "unknown",
#endif
		   /* These are reserved for later use */
		   0, 0, 0, 0);
#ifdef CONFIG_SMP
	seq_printf(m, " #P:%d)\n", num_online_cpus());
#else
	seq_puts(m, ")\n");
#endif
	seq_puts(m, "#    -----------------\n");
	seq_printf(m, "#    | task: %.16s-%d "
		   "(uid:%d nice:%ld policy:%ld rt_prio:%ld)\n",
		   data->comm, data->pid,
		   from_kuid_munged(seq_user_ns(m), data->uid), data->nice,
		   data->policy, data->rt_priority);
	seq_puts(m, "#    -----------------\n");

	if (data->critical_start) {
		seq_puts(m, "#  => started at: ");
		seq_print_ip_sym(&iter->seq, data->critical_start, sym_flags);
		trace_print_seq(m, &iter->seq);
		seq_puts(m, "\n#  => ended at:   ");
		seq_print_ip_sym(&iter->seq, data->critical_end, sym_flags);
		trace_print_seq(m, &iter->seq);
		seq_puts(m, "\n#\n");
	}

	seq_puts(m, "#\n");
}

static void test_cpu_buff_start(struct trace_iterator *iter)
{
	struct trace_seq *s = &iter->seq;

	if (!(trace_flags & TRACE_ITER_ANNOTATE))
		return;

	if (!(iter->iter_flags & TRACE_FILE_ANNOTATE))
		return;

	if (cpumask_test_cpu(iter->cpu, iter->started))
		return;

	if (per_cpu_ptr(iter->trace_buffer->data, iter->cpu)->skipped_entries)
		return;

	cpumask_set_cpu(iter->cpu, iter->started);

	/* Don't print started cpu buffer for the first entry of the trace */
	if (iter->idx > 1)
		trace_seq_printf(s, "##### CPU %u buffer started ####\n",
				iter->cpu);
}

static enum print_line_t print_trace_fmt(struct trace_iterator *iter)
{
	struct trace_seq *s = &iter->seq;
	unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
	struct trace_entry *entry;
	struct trace_event *event;

	entry = iter->ent;

	test_cpu_buff_start(iter);

	event = ftrace_find_event(entry->type);

	if (trace_flags & TRACE_ITER_CONTEXT_INFO) {
		if (iter->iter_flags & TRACE_FILE_LAT_FMT) {
			if (!trace_print_lat_context(iter))
				goto partial;
		} else {
			if (!trace_print_context(iter))
				goto partial;
		}
	}

	if (event)
		return event->funcs->trace(iter, sym_flags, event);

	if (!trace_seq_printf(s, "Unknown type %d\n", entry->type))
		goto partial;

	return TRACE_TYPE_HANDLED;
partial:
	return TRACE_TYPE_PARTIAL_LINE;
}

static enum print_line_t print_raw_fmt(struct trace_iterator *iter)
{
	struct trace_seq *s = &iter->seq;
	struct trace_entry *entry;
	struct trace_event *event;

	entry = iter->ent;

	if (trace_flags & TRACE_ITER_CONTEXT_INFO) {
		if (!trace_seq_printf(s, "%d %d %llu ",
				      entry->pid, iter->cpu, iter->ts))
			goto partial;
	}

	event = ftrace_find_event(entry->type);
	if (event)
		return event->funcs->raw(iter, 0, event);

	if (!trace_seq_printf(s, "%d ?\n", entry->type))
		goto partial;

	return TRACE_TYPE_HANDLED;
partial:
	return TRACE_TYPE_PARTIAL_LINE;
}

static enum print_line_t print_hex_fmt(struct trace_iterator *iter)
{
	struct trace_seq *s = &iter->seq;
	unsigned char newline = '\n';
	struct trace_entry *entry;
	struct trace_event *event;

	entry = iter->ent;

	if (trace_flags & TRACE_ITER_CONTEXT_INFO) {
		SEQ_PUT_HEX_FIELD_RET(s, entry->pid);
		SEQ_PUT_HEX_FIELD_RET(s, iter->cpu);
		SEQ_PUT_HEX_FIELD_RET(s, iter->ts);
	}

	event = ftrace_find_event(entry->type);
	if (event) {
		enum print_line_t ret = event->funcs->hex(iter, 0, event);
		if (ret != TRACE_TYPE_HANDLED)
			return ret;
	}

	SEQ_PUT_FIELD_RET(s, newline);

	return TRACE_TYPE_HANDLED;
}

static enum print_line_t print_bin_fmt(struct trace_iterator *iter)
{
	struct trace_seq *s = &iter->seq;
	struct trace_entry *entry;
	struct trace_event *event;

	entry = iter->ent;

	if (trace_flags & TRACE_ITER_CONTEXT_INFO) {
		SEQ_PUT_FIELD_RET(s, entry->pid);
		SEQ_PUT_FIELD_RET(s, iter->cpu);
		SEQ_PUT_FIELD_RET(s, iter->ts);
	}

	event = ftrace_find_event(entry->type);
	return event ? event->funcs->binary(iter, 0, event) :
		TRACE_TYPE_HANDLED;
}

int trace_empty(struct trace_iterator *iter)
{
	struct ring_buffer_iter *buf_iter;
	int cpu;

	/* If we are looking at one CPU buffer, only check that one */
	if (iter->cpu_file != RING_BUFFER_ALL_CPUS) {
		cpu = iter->cpu_file;
		buf_iter = trace_buffer_iter(iter, cpu);
		if (buf_iter) {
			if (!ring_buffer_iter_empty(buf_iter))
				return 0;
		} else {
			if (!ring_buffer_empty_cpu(iter->trace_buffer->buffer, cpu))
				return 0;
		}
		return 1;
	}

	for_each_tracing_cpu(cpu) {
		buf_iter = trace_buffer_iter(iter, cpu);
		if (buf_iter) {
			if (!ring_buffer_iter_empty(buf_iter))
				return 0;
		} else {
			if (!ring_buffer_empty_cpu(iter->trace_buffer->buffer, cpu))
				return 0;
		}
	}

	return 1;
}

/*  Called with trace_event_read_lock() held. */
enum print_line_t print_trace_line(struct trace_iterator *iter)
{
	enum print_line_t ret;

	if (iter->lost_events &&
	    !trace_seq_printf(&iter->seq, "CPU:%d [LOST %lu EVENTS]\n",
				 iter->cpu, iter->lost_events))
		return TRACE_TYPE_PARTIAL_LINE;

	if (iter->trace && iter->trace->print_line) {
		ret = iter->trace->print_line(iter);
		if (ret != TRACE_TYPE_UNHANDLED)
			return ret;
	}

	if (iter->ent->type == TRACE_BPUTS &&
			trace_flags & TRACE_ITER_PRINTK &&
			trace_flags & TRACE_ITER_PRINTK_MSGONLY)
		return trace_print_bputs_msg_only(iter);

	if (iter->ent->type == TRACE_BPRINT &&
			trace_flags & TRACE_ITER_PRINTK &&
			trace_flags & TRACE_ITER_PRINTK_MSGONLY)
		return trace_print_bprintk_msg_only(iter);

	if (iter->ent->type == TRACE_PRINT &&
			trace_flags & TRACE_ITER_PRINTK &&
			trace_flags & TRACE_ITER_PRINTK_MSGONLY)
		return trace_print_printk_msg_only(iter);

	if (trace_flags & TRACE_ITER_BIN)
		return print_bin_fmt(iter);

	if (trace_flags & TRACE_ITER_HEX)
		return print_hex_fmt(iter);

	if (trace_flags & TRACE_ITER_RAW)
		return print_raw_fmt(iter);

	return print_trace_fmt(iter);
}

void trace_latency_header(struct seq_file *m)
{
	struct trace_iterator *iter = m->private;

	/* print nothing if the buffers are empty */
	if (trace_empty(iter))
		return;

	if (iter->iter_flags & TRACE_FILE_LAT_FMT)
		print_trace_header(m, iter);

	if (!(trace_flags & TRACE_ITER_VERBOSE))
		print_lat_help_header(m);
}

void trace_default_header(struct seq_file *m)
{
	struct trace_iterator *iter = m->private;

	if (!(trace_flags & TRACE_ITER_CONTEXT_INFO))
		return;

	if (iter->iter_flags & TRACE_FILE_LAT_FMT) {
		/* print nothing if the buffers are empty */
		if (trace_empty(iter))
			return;
		print_trace_header(m, iter);
		if (!(trace_flags & TRACE_ITER_VERBOSE))
			print_lat_help_header(m);
	} else {
		if (!(trace_flags & TRACE_ITER_VERBOSE)) {
			if (trace_flags & TRACE_ITER_IRQ_INFO)
				print_func_help_header_irq(iter->trace_buffer, m);
			else
				print_func_help_header(iter->trace_buffer, m);
		}
	}
}

static void test_ftrace_alive(struct seq_file *m)
{
	if (!ftrace_is_dead())
		return;
	seq_printf(m, "# WARNING: FUNCTION TRACING IS CORRUPTED\n");
	seq_printf(m, "#          MAY BE MISSING FUNCTION EVENTS\n");
}

#ifdef CONFIG_TRACER_MAX_TRACE
static void show_snapshot_main_help(struct seq_file *m)
{
	seq_printf(m, "# echo 0 > snapshot : Clears and frees snapshot buffer\n");
	seq_printf(m, "# echo 1 > snapshot : Allocates snapshot buffer, if not already allocated.\n");
	seq_printf(m, "#                      Takes a snapshot of the main buffer.\n");
	seq_printf(m, "# echo 2 > snapshot : Clears snapshot buffer (but does not allocate)\n");
	seq_printf(m, "#                      (Doesn't have to be '2' works with any number that\n");
	seq_printf(m, "#                       is not a '0' or '1')\n");
}

static void show_snapshot_percpu_help(struct seq_file *m)
{
	seq_printf(m, "# echo 0 > snapshot : Invalid for per_cpu snapshot file.\n");
#ifdef CONFIG_RING_BUFFER_ALLOW_SWAP
	seq_printf(m, "# echo 1 > snapshot : Allocates snapshot buffer, if not already allocated.\n");
	seq_printf(m, "#                      Takes a snapshot of the main buffer for this cpu.\n");
#else
	seq_printf(m, "# echo 1 > snapshot : Not supported with this kernel.\n");
	seq_printf(m, "#                     Must use main snapshot file to allocate.\n");
#endif
	seq_printf(m, "# echo 2 > snapshot : Clears this cpu's snapshot buffer (but does not allocate)\n");
	seq_printf(m, "#                      (Doesn't have to be '2' works with any number that\n");
	seq_printf(m, "#                       is not a '0' or '1')\n");
}

static void print_snapshot_help(struct seq_file *m, struct trace_iterator *iter)
{
	if (iter->tr->allocated_snapshot)
		seq_printf(m, "#\n# * Snapshot is allocated *\n#\n");
	else
		seq_printf(m, "#\n# * Snapshot is freed *\n#\n");

	seq_printf(m, "# Snapshot commands:\n");
	if (iter->cpu_file == RING_BUFFER_ALL_CPUS)
		show_snapshot_main_help(m);
	else
		show_snapshot_percpu_help(m);
}
#else
/* Should never be called */
static inline void print_snapshot_help(struct seq_file *m, struct trace_iterator *iter) { }
#endif

static int s_show(struct seq_file *m, void *v)
{
	struct trace_iterator *iter = v;
	int ret;

	if (iter->ent == NULL) {
		if (iter->tr) {
			seq_printf(m, "# tracer: %s\n", iter->trace->name);
			seq_puts(m, "#\n");
			test_ftrace_alive(m);
		}
		if (iter->snapshot && trace_empty(iter))
			print_snapshot_help(m, iter);
		else if (iter->trace && iter->trace->print_header)
			iter->trace->print_header(m);
		else
			trace_default_header(m);

	} else if (iter->leftover) {
		/*
		 * If we filled the seq_file buffer earlier, we
		 * want to just show it now.
		 */
		ret = trace_print_seq(m, &iter->seq);

		/* ret should this time be zero, but you never know */
		iter->leftover = ret;

	} else {
		print_trace_line(iter);
		ret = trace_print_seq(m, &iter->seq);
		/*
		 * If we overflow the seq_file buffer, then it will
		 * ask us for this data again at start up.
		 * Use that instead.
		 *  ret is 0 if seq_file write succeeded.
		 *        -1 otherwise.
		 */
		iter->leftover = ret;
	}

	return 0;
}

/*
 * Should be used after trace_array_get(), trace_types_lock
 * ensures that i_cdev was already initialized.
 */
static inline int tracing_get_cpu(struct inode *inode)
{
	if (inode->i_cdev) /* See trace_create_cpu_file() */
		return (long)inode->i_cdev - 1;
	return RING_BUFFER_ALL_CPUS;
}

static const struct seq_operations tracer_seq_ops = {
	.start		= s_start,
	.next		= s_next,
	.stop		= s_stop,
	.show		= s_show,
};

static struct trace_iterator *
__tracing_open(struct inode *inode, struct file *file, bool snapshot)
{
	struct trace_array *tr = inode->i_private;
	struct trace_iterator *iter;
	int cpu;

	if (tracing_disabled)
		return ERR_PTR(-ENODEV);

	iter = __seq_open_private(file, &tracer_seq_ops, sizeof(*iter));
	if (!iter)
		return ERR_PTR(-ENOMEM);

	iter->buffer_iter = kzalloc(sizeof(*iter->buffer_iter) * num_possible_cpus(),
				    GFP_KERNEL);
	if (!iter->buffer_iter)
		goto release;

	/*
	 * We make a copy of the current tracer to avoid concurrent
	 * changes on it while we are reading.
	 */
	mutex_lock(&trace_types_lock);
	iter->trace = kzalloc(sizeof(*iter->trace), GFP_KERNEL);
	if (!iter->trace)
		goto fail;

	*iter->trace = *tr->current_trace;

	if (!zalloc_cpumask_var(&iter->started, GFP_KERNEL))
		goto fail;

	iter->tr = tr;

#ifdef CONFIG_TRACER_MAX_TRACE
	/* Currently only the top directory has a snapshot */
	if (tr->current_trace->print_max || snapshot)
		iter->trace_buffer = &tr->max_buffer;
	else
#endif
		iter->trace_buffer = &tr->trace_buffer;
	iter->snapshot = snapshot;
	iter->pos = -1;
	iter->cpu_file = tracing_get_cpu(inode);
	mutex_init(&iter->mutex);

	/* Notify the tracer early; before we stop tracing. */
	if (iter->trace && iter->trace->open)
		iter->trace->open(iter);

	/* Annotate start of buffers if we had overruns */
	if (ring_buffer_overruns(iter->trace_buffer->buffer))
		iter->iter_flags |= TRACE_FILE_ANNOTATE;

	/* Output in nanoseconds only if we are using a clock in nanoseconds. */
	if (trace_clocks[tr->clock_id].in_ns)
		iter->iter_flags |= TRACE_FILE_TIME_IN_NS;

	/* stop the trace while dumping if we are not opening "snapshot" */
	if (!iter->snapshot)
		tracing_stop_tr(tr);

	if (iter->cpu_file == RING_BUFFER_ALL_CPUS) {
		for_each_tracing_cpu(cpu) {
			iter->buffer_iter[cpu] =
				ring_buffer_read_prepare(iter->trace_buffer->buffer, cpu);
		}
		ring_buffer_read_prepare_sync();
		for_each_tracing_cpu(cpu) {
			ring_buffer_read_start(iter->buffer_iter[cpu]);
			tracing_iter_reset(iter, cpu);
		}
	} else {
		cpu = iter->cpu_file;
		iter->buffer_iter[cpu] =
			ring_buffer_read_prepare(iter->trace_buffer->buffer, cpu);
		ring_buffer_read_prepare_sync();
		ring_buffer_read_start(iter->buffer_iter[cpu]);
		tracing_iter_reset(iter, cpu);
	}

	mutex_unlock(&trace_types_lock);

	return iter;

 fail:
	mutex_unlock(&trace_types_lock);
	kfree(iter->trace);
	kfree(iter->buffer_iter);
release:
	seq_release_private(inode, file);
	return ERR_PTR(-ENOMEM);
}

int tracing_open_generic(struct inode *inode, struct file *filp)
{
	if (tracing_disabled)
		return -ENODEV;

	filp->private_data = inode->i_private;
	return 0;
}

/*
 * Open and update trace_array ref count.
 * Must have the current trace_array passed to it.
 */
int tracing_open_generic_tr(struct inode *inode, struct file *filp)
{
	struct trace_array *tr = inode->i_private;

	if (tracing_disabled)
		return -ENODEV;

	if (trace_array_get(tr) < 0)
		return -ENODEV;

	filp->private_data = inode->i_private;

	return 0;
}

static int tracing_release(struct inode *inode, struct file *file)
{
	struct trace_array *tr = inode->i_private;
	struct seq_file *m = file->private_data;
	struct trace_iterator *iter;
	int cpu;

	if (!(file->f_mode & FMODE_READ)) {
		trace_array_put(tr);
		return 0;
	}

	/* Writes do not use seq_file */
	iter = m->private;
	mutex_lock(&trace_types_lock);

	for_each_tracing_cpu(cpu) {
		if (iter->buffer_iter[cpu])
			ring_buffer_read_finish(iter->buffer_iter[cpu]);
	}

	if (iter->trace && iter->trace->close)
		iter->trace->close(iter);

	if (!iter->snapshot)
		/* reenable tracing if it was previously enabled */
		tracing_start_tr(tr);

	__trace_array_put(tr);

	mutex_unlock(&trace_types_lock);

	mutex_destroy(&iter->mutex);
	free_cpumask_var(iter->started);
	kfree(iter->trace);
	kfree(iter->buffer_iter);
	seq_release_private(inode, file);

	return 0;
}

static int tracing_release_generic_tr(struct inode *inode, struct file *file)
{
	struct trace_array *tr = inode->i_private;

	trace_array_put(tr);
	return 0;
}

static int tracing_single_release_tr(struct inode *inode, struct file *file)
{
	struct trace_array *tr = inode->i_private;

	trace_array_put(tr);

	return single_release(inode, file);
}

static int tracing_open(struct inode *inode, struct file *file)
{
	struct trace_array *tr = inode->i_private;
	struct trace_iterator *iter;
	int ret = 0;

	if (trace_array_get(tr) < 0)
		return -ENODEV;

	/* If this file was open for write, then erase contents */
	if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
		int cpu = tracing_get_cpu(inode);

		if (cpu == RING_BUFFER_ALL_CPUS)
			tracing_reset_online_cpus(&tr->trace_buffer);
		else
			tracing_reset(&tr->trace_buffer, cpu);
	}

	if (file->f_mode & FMODE_READ) {
		iter = __tracing_open(inode, file, false);
		if (IS_ERR(iter))
			ret = PTR_ERR(iter);
		else if (trace_flags & TRACE_ITER_LATENCY_FMT)
			iter->iter_flags |= TRACE_FILE_LAT_FMT;
	}

	if (ret < 0)
		trace_array_put(tr);

	return ret;
}

static void *
t_next(struct seq_file *m, void *v, loff_t *pos)
{
	struct tracer *t = v;

	(*pos)++;

	if (t)
		t = t->next;

	return t;
}

static void *t_start(struct seq_file *m, loff_t *pos)
{
	struct tracer *t;
	loff_t l = 0;

	mutex_lock(&trace_types_lock);
	for (t = trace_types; t && l < *pos; t = t_next(m, t, &l))
		;

	return t;
}

static void t_stop(struct seq_file *m, void *p)
{
	mutex_unlock(&trace_types_lock);
}

static int t_show(struct seq_file *m, void *v)
{
	struct tracer *t = v;

	if (!t)
		return 0;

	seq_printf(m, "%s", t->name);
	if (t->next)
		seq_putc(m, ' ');
	else
		seq_putc(m, '\n');

	return 0;
}

static const struct seq_operations show_traces_seq_ops = {
	.start		= t_start,
	.next		= t_next,
	.stop		= t_stop,
	.show		= t_show,
};

static int show_traces_open(struct inode *inode, struct file *file)
{
	if (tracing_disabled)
		return -ENODEV;

	return seq_open(file, &show_traces_seq_ops);
}

static ssize_t
tracing_write_stub(struct file *filp, const char __user *ubuf,
		   size_t count, loff_t *ppos)
{
	return count;
}

static loff_t tracing_seek(struct file *file, loff_t offset, int origin)
{
	if (file->f_mode & FMODE_READ)
		return seq_lseek(file, offset, origin);
	else
		return 0;
}

static const struct file_operations tracing_fops = {
	.open		= tracing_open,
	.read		= seq_read,
	.write		= tracing_write_stub,
	.llseek		= tracing_seek,
	.release	= tracing_release,
};

static const struct file_operations show_traces_fops = {
	.open		= show_traces_open,
	.read		= seq_read,
	.release	= seq_release,
	.llseek		= seq_lseek,
};

/*
 * Only trace on a CPU if the bitmask is set:
 */
static cpumask_var_t tracing_cpumask;

/*
 * The tracer itself will not take this lock, but still we want
 * to provide a consistent cpumask to user-space:
 */
static DEFINE_MUTEX(tracing_cpumask_update_lock);

/*
 * Temporary storage for the character representation of the
 * CPU bitmask (and one more byte for the newline):
 */
static char mask_str[NR_CPUS + 1];

static ssize_t
tracing_cpumask_read(struct file *filp, char __user *ubuf,
		     size_t count, loff_t *ppos)
{
	int len;

	mutex_lock(&tracing_cpumask_update_lock);

	len = cpumask_scnprintf(mask_str, count, tracing_cpumask);
	if (count - len < 2) {
		count = -EINVAL;
		goto out_err;
	}
	len += sprintf(mask_str + len, "\n");
	count = simple_read_from_buffer(ubuf, count, ppos, mask_str, NR_CPUS+1);

out_err:
	mutex_unlock(&tracing_cpumask_update_lock);

	return count;
}

static ssize_t
tracing_cpumask_write(struct file *filp, const char __user *ubuf,
		      size_t count, loff_t *ppos)
{
	struct trace_array *tr = filp->private_data;
	cpumask_var_t tracing_cpumask_new;
	int err, cpu;

	if (!alloc_cpumask_var(&tracing_cpumask_new, GFP_KERNEL))
		return -ENOMEM;

	err = cpumask_parse_user(ubuf, count, tracing_cpumask_new);
	if (err)
		goto err_unlock;

	mutex_lock(&tracing_cpumask_update_lock);

	local_irq_disable();
	arch_spin_lock(&ftrace_max_lock);
	for_each_tracing_cpu(cpu) {
		/*
		 * Increase/decrease the disabled counter if we are
		 * about to flip a bit in the cpumask:
		 */
		if (cpumask_test_cpu(cpu, tracing_cpumask) &&
				!cpumask_test_cpu(cpu, tracing_cpumask_new)) {
			atomic_inc(&per_cpu_ptr(tr->trace_buffer.data, cpu)->disabled);
			ring_buffer_record_disable_cpu(tr->trace_buffer.buffer, cpu);
		}
		if (!cpumask_test_cpu(cpu, tracing_cpumask) &&
				cpumask_test_cpu(cpu, tracing_cpumask_new)) {
			atomic_dec(&per_cpu_ptr(tr->trace_buffer.data, cpu)->disabled);
			ring_buffer_record_enable_cpu(tr->trace_buffer.buffer, cpu);
		}
	}
	arch_spin_unlock(&ftrace_max_lock);
	local_irq_enable();

	cpumask_copy(tracing_cpumask, tracing_cpumask_new);

	mutex_unlock(&tracing_cpumask_update_lock);
	free_cpumask_var(tracing_cpumask_new);

	return count;

err_unlock:
	free_cpumask_var(tracing_cpumask_new);

	return err;
}

static const struct file_operations tracing_cpumask_fops = {
	.open		= tracing_open_generic,
	.read		= tracing_cpumask_read,
	.write		= tracing_cpumask_write,
	.llseek		= generic_file_llseek,
};

static int tracing_trace_options_show(struct seq_file *m, void *v)
{
	struct tracer_opt *trace_opts;
	struct trace_array *tr = m->private;
	u32 tracer_flags;
	int i;

	mutex_lock(&trace_types_lock);
	tracer_flags = tr->current_trace->flags->val;
	trace_opts = tr->current_trace->flags->opts;

	for (i = 0; trace_options[i]; i++) {
		if (trace_flags & (1 << i))
			seq_printf(m, "%s\n", trace_options[i]);
		else
			seq_printf(m, "no%s\n", trace_options[i]);
	}

	for (i = 0; trace_opts[i].name; i++) {
		if (tracer_flags & trace_opts[i].bit)
			seq_printf(m, "%s\n", trace_opts[i].name);
		else
			seq_printf(m, "no%s\n", trace_opts[i].name);
	}
	mutex_unlock(&trace_types_lock);

	return 0;
}

static int __set_tracer_option(struct tracer *trace,
			       struct tracer_flags *tracer_flags,
			       struct tracer_opt *opts, int neg)
{
	int ret;

	ret = trace->set_flag(tracer_flags->val, opts->bit, !neg);
	if (ret)
		return ret;

	if (neg)
		tracer_flags->val &= ~opts->bit;
	else
		tracer_flags->val |= opts->bit;
	return 0;
}

/* Try to assign a tracer specific option */
static int set_tracer_option(struct tracer *trace, char *cmp, int neg)
{
	struct tracer_flags *tracer_flags = trace->flags;
	struct tracer_opt *opts = NULL;
	int i;

	for (i = 0; tracer_flags->opts[i].name; i++) {
		opts = &tracer_flags->opts[i];

		if (strcmp(cmp, opts->name) == 0)
			return __set_tracer_option(trace, trace->flags,
						   opts, neg);
	}

	return -EINVAL;
}

/* Some tracers require overwrite to stay enabled */
int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set)
{
	if (tracer->enabled && (mask & TRACE_ITER_OVERWRITE) && !set)
		return -1;

	return 0;
}

int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled)
{
	/* do nothing if flag is already set */
	if (!!(trace_flags & mask) == !!enabled)
		return 0;

	/* Give the tracer a chance to approve the change */
	if (tr->current_trace->flag_changed)
		if (tr->current_trace->flag_changed(tr->current_trace, mask, !!enabled))
			return -EINVAL;

	if (enabled)
		trace_flags |= mask;
	else
		trace_flags &= ~mask;

	if (mask == TRACE_ITER_RECORD_CMD)
		trace_event_enable_cmd_record(enabled);

	if (mask == TRACE_ITER_OVERWRITE) {
		ring_buffer_change_overwrite(tr->trace_buffer.buffer, enabled);
#ifdef CONFIG_TRACER_MAX_TRACE
		ring_buffer_change_overwrite(tr->max_buffer.buffer, enabled);
#endif
	}

	if (mask == TRACE_ITER_PRINTK)
		trace_printk_start_stop_comm(enabled);

	return 0;
}

static int trace_set_options(struct trace_array *tr, char *option)
{
	char *cmp;
	int neg = 0;
	int ret = -ENODEV;
	int i;

	cmp = strstrip(option);

	if (strncmp(cmp, "no", 2) == 0) {
		neg = 1;
		cmp += 2;
	}

	mutex_lock(&trace_types_lock);

	for (i = 0; trace_options[i]; i++) {
		if (strcmp(cmp, trace_options[i]) == 0) {
			ret = set_tracer_flag(tr, 1 << i, !neg);
			break;
		}
	}

	/* If no option could be set, test the specific tracer options */
	if (!trace_options[i])
		ret = set_tracer_option(tr->current_trace, cmp, neg);

	mutex_unlock(&trace_types_lock);

	return ret;
}

static ssize_t
tracing_trace_options_write(struct file *filp, const char __user *ubuf,
			size_t cnt, loff_t *ppos)
{
	struct seq_file *m = filp->private_data;
	struct trace_array *tr = m->private;
	char buf[64];
	int ret;

	if (cnt >= sizeof(buf))
		return -EINVAL;

	if (copy_from_user(&buf, ubuf, cnt))
		return -EFAULT;

	buf[cnt] = 0;

	ret = trace_set_options(tr, buf);
	if (ret < 0)
		return ret;

	*ppos += cnt;

	return cnt;
}

static int tracing_trace_options_open(struct inode *inode, struct file *file)
{
	struct trace_array *tr = inode->i_private;
	int ret;

	if (tracing_disabled)
		return -ENODEV;

	if (trace_array_get(tr) < 0)
		return -ENODEV;

	ret = single_open(file, tracing_trace_options_show, inode->i_private);
	if (ret < 0)
		trace_array_put(tr);

	return ret;
}

static const struct file_operations tracing_iter_fops = {
	.open		= tracing_trace_options_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= tracing_single_release_tr,
	.write		= tracing_trace_options_write,
};

static const char readme_msg[] =
	"tracing mini-HOWTO:\n\n"
	"# echo 0 > tracing_on : quick way to disable tracing\n"
	"# echo 1 > tracing_on : quick way to re-enable tracing\n\n"
	" Important files:\n"
	"  trace\t\t\t- The static contents of the buffer\n"
	"\t\t\t  To clear the buffer write into this file: echo > trace\n"
	"  trace_pipe\t\t- A consuming read to see the contents of the buffer\n"
	"  current_tracer\t- function and latency tracers\n"
	"  available_tracers\t- list of configured tracers for current_tracer\n"
	"  buffer_size_kb\t- view and modify size of per cpu buffer\n"
	"  buffer_total_size_kb  - view total size of all cpu buffers\n\n"
	"  trace_clock\t\t-change the clock used to order events\n"
	"       local:   Per cpu clock but may not be synced across CPUs\n"
	"      global:   Synced across CPUs but slows tracing down.\n"
	"     counter:   Not a clock, but just an increment\n"
	"      uptime:   Jiffy counter from time of boot\n"
	"        perf:   Same clock that perf events use\n"
#ifdef CONFIG_X86_64
	"     x86-tsc:   TSC cycle counter\n"
#endif
	"\n  trace_marker\t\t- Writes into this file writes into the kernel buffer\n"
	"  tracing_cpumask\t- Limit which CPUs to trace\n"
	"  instances\t\t- Make sub-buffers with: mkdir instances/foo\n"
	"\t\t\t  Remove sub-buffer with rmdir\n"
	"  trace_options\t\t- Set format or modify how tracing happens\n"
	"\t\t\t  Disable an option by adding a suffix 'no' to the option name\n"
#ifdef CONFIG_DYNAMIC_FTRACE
	"\n  available_filter_functions - list of functions that can be filtered on\n"
	"  set_ftrace_filter\t- echo function name in here to only trace these functions\n"
	"            accepts: func_full_name, *func_end, func_begin*, *func_middle*\n"
	"            modules: Can select a group via module\n"
	"             Format: :mod:<module-name>\n"
	"             example: echo :mod:ext3 > set_ftrace_filter\n"
	"            triggers: a command to perform when function is hit\n"
	"              Format: <function>:<trigger>[:count]\n"
	"             trigger: traceon, traceoff\n"
	"                      enable_event:<system>:<event>\n"
	"                      disable_event:<system>:<event>\n"
#ifdef CONFIG_STACKTRACE
	"                      stacktrace\n"
#endif
#ifdef CONFIG_TRACER_SNAPSHOT
	"                      snapshot\n"
#endif
	"             example: echo do_fault:traceoff > set_ftrace_filter\n"
	"                      echo do_trap:traceoff:3 > set_ftrace_filter\n"
	"             The first one will disable tracing every time do_fault is hit\n"
	"             The second will disable tracing at most 3 times when do_trap is hit\n"
	"               The first time do trap is hit and it disables tracing, the counter\n"
	"               will decrement to 2. If tracing is already disabled, the counter\n"
	"               will not decrement. It only decrements when the trigger did work\n"
	"             To remove trigger without count:\n"
	"               echo '!<function>:<trigger> > set_ftrace_filter\n"
	"             To remove trigger with a count:\n"
	"               echo '!<function>:<trigger>:0 > set_ftrace_filter\n"
	"  set_ftrace_notrace\t- echo function name in here to never trace.\n"
	"            accepts: func_full_name, *func_end, func_begin*, *func_middle*\n"
	"            modules: Can select a group via module command :mod:\n"
	"            Does not accept triggers\n"
#endif /* CONFIG_DYNAMIC_FTRACE */
#ifdef CONFIG_FUNCTION_TRACER
	"  set_ftrace_pid\t- Write pid(s) to only function trace those pids (function)\n"
#endif
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
	"  set_graph_function\t- Trace the nested calls of a function (function_graph)\n"
	"  max_graph_depth\t- Trace a limited depth of nested calls (0 is unlimited)\n"
#endif
#ifdef CONFIG_TRACER_SNAPSHOT
	"\n  snapshot\t\t- Like 'trace' but shows the content of the static snapshot buffer\n"
	"\t\t\t  Read the contents for more information\n"
#endif
#ifdef CONFIG_STACKTRACE
	"  stack_trace\t\t- Shows the max stack trace when active\n"
	"  stack_max_size\t- Shows current max stack size that was traced\n"
	"\t\t\t  Write into this file to reset the max size (trigger a new trace)\n"
#ifdef CONFIG_DYNAMIC_FTRACE
	"  stack_trace_filter\t- Like set_ftrace_filter but limits what stack_trace traces\n"
#endif
#endif /* CONFIG_STACKTRACE */
;

static ssize_t
tracing_readme_read(struct file *filp, char __user *ubuf,
		       size_t cnt, loff_t *ppos)
{
	return simple_read_from_buffer(ubuf, cnt, ppos,
					readme_msg, strlen(readme_msg));
}

static const struct file_operations tracing_readme_fops = {
	.open		= tracing_open_generic,
	.read		= tracing_readme_read,
	.llseek		= generic_file_llseek,
};

static ssize_t
tracing_saved_cmdlines_read(struct file *file, char __user *ubuf,
				size_t cnt, loff_t *ppos)
{
	char *buf_comm;
	char *file_buf;
	char *buf;
	int len = 0;
	int pid;
	int i;

	file_buf = kmalloc(SAVED_CMDLINES*(16+TASK_COMM_LEN), GFP_KERNEL);
	if (!file_buf)
		return -ENOMEM;

	buf_comm = kmalloc(TASK_COMM_LEN, GFP_KERNEL);
	if (!buf_comm) {
		kfree(file_buf);
		return -ENOMEM;
	}

	buf = file_buf;

	for (i = 0; i < SAVED_CMDLINES; i++) {
		int r;

		pid = map_cmdline_to_pid[i];
		if (pid == -1 || pid == NO_CMDLINE_MAP)
			continue;

		trace_find_cmdline(pid, buf_comm);
		r = sprintf(buf, "%d %s\n", pid, buf_comm);
		buf += r;
		len += r;
	}

	len = simple_read_from_buffer(ubuf, cnt, ppos,
				      file_buf, len);

	kfree(file_buf);
	kfree(buf_comm);

	return len;
}

static const struct file_operations tracing_saved_cmdlines_fops = {
    .open       = tracing_open_generic,
    .read       = tracing_saved_cmdlines_read,
    .llseek	= generic_file_llseek,
};

static ssize_t
tracing_set_trace_read(struct file *filp, char __user *ubuf,
		       size_t cnt, loff_t *ppos)
{
	struct trace_array *tr = filp->private_data;
	char buf[MAX_TRACER_SIZE+2];
	int r;

	mutex_lock(&trace_types_lock);
	r = sprintf(buf, "%s\n", tr->current_trace->name);
	mutex_unlock(&trace_types_lock);

	return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
}

int tracer_init(struct tracer *t, struct trace_array *tr)
{
	tracing_reset_online_cpus(&tr->trace_buffer);
	return t->init(tr);
}

static void set_buffer_entries(struct trace_buffer *buf, unsigned long val)
{
	int cpu;

	for_each_tracing_cpu(cpu)
		per_cpu_ptr(buf->data, cpu)->entries = val;
}

#ifdef CONFIG_TRACER_MAX_TRACE
/* resize @tr's buffer to the size of @size_tr's entries */
static int resize_buffer_duplicate_size(struct trace_buffer *trace_buf,
					struct trace_buffer *size_buf, int cpu_id)
{
	int cpu, ret = 0;

	if (cpu_id == RING_BUFFER_ALL_CPUS) {
		for_each_tracing_cpu(cpu) {
			ret = ring_buffer_resize(trace_buf->buffer,
				 per_cpu_ptr(size_buf->data, cpu)->entries, cpu);
			if (ret < 0)
				break;
			per_cpu_ptr(trace_buf->data, cpu)->entries =
				per_cpu_ptr(size_buf->data, cpu)->entries;
		}
	} else {
		ret = ring_buffer_resize(trace_buf->buffer,
				 per_cpu_ptr(size_buf->data, cpu_id)->entries, cpu_id);
		if (ret == 0)
			per_cpu_ptr(trace_buf->data, cpu_id)->entries =
				per_cpu_ptr(size_buf->data, cpu_id)->entries;
	}

	return ret;
}
#endif /* CONFIG_TRACER_MAX_TRACE */

static int __tracing_resize_ring_buffer(struct trace_array *tr,
					unsigned long size, int cpu)
{
	int ret;

	/*
	 * If kernel or user changes the size of the ring buffer
	 * we use the size that was given, and we can forget about
	 * expanding it later.
	 */
	ring_buffer_expanded = true;

	/* May be called before buffers are initialized */
	if (!tr->trace_buffer.buffer)
		return 0;

	ret = ring_buffer_resize(tr->trace_buffer.buffer, size, cpu);
	if (ret < 0)
		return ret;

#ifdef CONFIG_TRACER_MAX_TRACE
	if (!(tr->flags & TRACE_ARRAY_FL_GLOBAL) ||
	    !tr->current_trace->use_max_tr)
		goto out;

	ret = ring_buffer_resize(tr->max_buffer.buffer, size, cpu);
	if (ret < 0) {
		int r = resize_buffer_duplicate_size(&tr->trace_buffer,
						     &tr->trace_buffer, cpu);
		if (r < 0) {
			/*
			 * AARGH! We are left with different
			 * size max buffer!!!!
			 * The max buffer is our "snapshot" buffer.
			 * When a tracer needs a snapshot (one of the
			 * latency tracers), it swaps the max buffer
			 * with the saved snap shot. We succeeded to
			 * update the size of the main buffer, but failed to
			 * update the size of the max buffer. But when we tried
			 * to reset the main buffer to the original size, we
			 * failed there too. This is very unlikely to
			 * happen, but if it does, warn and kill all
			 * tracing.
			 */
			WARN_ON(1);
			tracing_disabled = 1;
		}
		return ret;
	}

	if (cpu == RING_BUFFER_ALL_CPUS)
		set_buffer_entries(&tr->max_buffer, size);
	else
		per_cpu_ptr(tr->max_buffer.data, cpu)->entries = size;

 out:
#endif /* CONFIG_TRACER_MAX_TRACE */

	if (cpu == RING_BUFFER_ALL_CPUS)
		set_buffer_entries(&tr->trace_buffer, size);
	else
		per_cpu_ptr(tr->trace_buffer.data, cpu)->entries = size;

	return ret;
}

static ssize_t tracing_resize_ring_buffer(struct trace_array *tr,
					  unsigned long size, int cpu_id)
{
	int ret = size;

	mutex_lock(&trace_types_lock);

	if (cpu_id != RING_BUFFER_ALL_CPUS) {
		/* make sure, this cpu is enabled in the mask */
		if (!cpumask_test_cpu(cpu_id, tracing_buffer_mask)) {
			ret = -EINVAL;
			goto out;
		}
	}

	ret = __tracing_resize_ring_buffer(tr, size, cpu_id);
	if (ret < 0)
		ret = -ENOMEM;

out:
	mutex_unlock(&trace_types_lock);

	return ret;
}


/**
 * tracing_update_buffers - used by tracing facility to expand ring buffers
 *
 * To save on memory when the tracing is never used on a system with it
 * configured in. The ring buffers are set to a minimum size. But once
 * a user starts to use the tracing facility, then they need to grow
 * to their default size.
 *
 * This function is to be called when a tracer is about to be used.
 */
int tracing_update_buffers(void)
{
	int ret = 0;

	mutex_lock(&trace_types_lock);
	if (!ring_buffer_expanded)
		ret = __tracing_resize_ring_buffer(&global_trace, trace_buf_size,
						RING_BUFFER_ALL_CPUS);
	mutex_unlock(&trace_types_lock);

	return ret;
}

struct trace_option_dentry;

static struct trace_option_dentry *
create_trace_option_files(struct trace_array *tr, struct tracer *tracer);

static void
destroy_trace_option_files(struct trace_option_dentry *topts);

static int tracing_set_tracer(const char *buf)
{
	static struct trace_option_dentry *topts;
	struct trace_array *tr = &global_trace;
	struct tracer *t;
#ifdef CONFIG_TRACER_MAX_TRACE
	bool had_max_tr;
#endif
	int ret = 0;

	mutex_lock(&trace_types_lock);

	if (!ring_buffer_expanded) {
		ret = __tracing_resize_ring_buffer(tr, trace_buf_size,
						RING_BUFFER_ALL_CPUS);
		if (ret < 0)
			goto out;
		ret = 0;
	}

	for (t = trace_types; t; t = t->next) {
		if (strcmp(t->name, buf) == 0)
			break;
	}
	if (!t) {
		ret = -EINVAL;
		goto out;
	}
	if (t == tr->current_trace)
		goto out;

	trace_branch_disable();

	tr->current_trace->enabled = false;

	if (tr->current_trace->reset)
		tr->current_trace->reset(tr);

	/* Current trace needs to be nop_trace before synchronize_sched */
	tr->current_trace = &nop_trace;

#ifdef CONFIG_TRACER_MAX_TRACE
	had_max_tr = tr->allocated_snapshot;

	if (had_max_tr && !t->use_max_tr) {
		/*
		 * We need to make sure that the update_max_tr sees that
		 * current_trace changed to nop_trace to keep it from
		 * swapping the buffers after we resize it.
		 * The update_max_tr is called from interrupts disabled
		 * so a synchronized_sched() is sufficient.
		 */
		synchronize_sched();
		free_snapshot(tr);
	}
#endif
	destroy_trace_option_files(topts);

	topts = create_trace_option_files(tr, t);

#ifdef CONFIG_TRACER_MAX_TRACE
	if (t->use_max_tr && !had_max_tr) {
		ret = alloc_snapshot(tr);
		if (ret < 0)
			goto out;
	}
#endif

	if (t->init) {
		ret = tracer_init(t, tr);
		if (ret)
			goto out;
	}

	tr->current_trace = t;
	tr->current_trace->enabled = true;
	trace_branch_enable(tr);
 out:
	mutex_unlock(&trace_types_lock);

	return ret;
}

static ssize_t
tracing_set_trace_write(struct file *filp, const char __user *ubuf,
			size_t cnt, loff_t *ppos)
{
	char buf[MAX_TRACER_SIZE+1];
	int i;
	size_t ret;
	int err;

	ret = cnt;

	if (cnt > MAX_TRACER_SIZE)
		cnt = MAX_TRACER_SIZE;

	if (copy_from_user(&buf, ubuf, cnt))
		return -EFAULT;

	buf[cnt] = 0;

	/* strip ending whitespace. */
	for (i = cnt - 1; i > 0 && isspace(buf[i]); i--)
		buf[i] = 0;

	err = tracing_set_tracer(buf);
	if (err)
		return err;

	*ppos += ret;

	return ret;
}

static ssize_t
tracing_max_lat_read(struct file *filp, char __user *ubuf,
		     size_t cnt, loff_t *ppos)
{
	unsigned long *ptr = filp->private_data;
	char buf[64];
	int r;

	r = snprintf(buf, sizeof(buf), "%ld\n",
		     *ptr == (unsigned long)-1 ? -1 : nsecs_to_usecs(*ptr));
	if (r > sizeof(buf))
		r = sizeof(buf);
	return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
}

static ssize_t
tracing_max_lat_write(struct file *filp, const char __user *ubuf,
		      size_t cnt, loff_t *ppos)
{
	unsigned long *ptr = filp->private_data;
	unsigned long val;
	int ret;

	ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
	if (ret)
		return ret;

	*ptr = val * 1000;

	return cnt;
}

static int tracing_open_pipe(struct inode *inode, struct file *filp)
{
	struct trace_array *tr = inode->i_private;
	struct trace_iterator *iter;
	int ret = 0;

	if (tracing_disabled)
		return -ENODEV;

	if (trace_array_get(tr) < 0)
		return -ENODEV;

	mutex_lock(&trace_types_lock);

	/* create a buffer to store the information to pass to userspace */
	iter = kzalloc(sizeof(*iter), GFP_KERNEL);
	if (!iter) {
		ret = -ENOMEM;
		__trace_array_put(tr);
		goto out;
	}

	/*
	 * We make a copy of the current tracer to avoid concurrent
	 * changes on it while we are reading.
	 */
	iter->trace = kmalloc(sizeof(*iter->trace), GFP_KERNEL);
	if (!iter->trace) {
		ret = -ENOMEM;
		goto fail;
	}
	*iter->trace = *tr->current_trace;

	if (!alloc_cpumask_var(&iter->started, GFP_KERNEL)) {
		ret = -ENOMEM;
		goto fail;
	}

	/* trace pipe does not show start of buffer */
	cpumask_setall(iter->started);

	if (trace_flags & TRACE_ITER_LATENCY_FMT)
		iter->iter_flags |= TRACE_FILE_LAT_FMT;

	/* Output in nanoseconds only if we are using a clock in nanoseconds. */
	if (trace_clocks[tr->clock_id].in_ns)
		iter->iter_flags |= TRACE_FILE_TIME_IN_NS;

	iter->tr = tr;
	iter->trace_buffer = &tr->trace_buffer;
	iter->cpu_file = tracing_get_cpu(inode);
	mutex_init(&iter->mutex);
	filp->private_data = iter;

	if (iter->trace->pipe_open)
		iter->trace->pipe_open(iter);

	nonseekable_open(inode, filp);
out:
	mutex_unlock(&trace_types_lock);
	return ret;

fail:
	kfree(iter->trace);
	kfree(iter);
	__trace_array_put(tr);
	mutex_unlock(&trace_types_lock);
	return ret;
}

static int tracing_release_pipe(struct inode *inode, struct file *file)
{
	struct trace_iterator *iter = file->private_data;
	struct trace_array *tr = inode->i_private;

	mutex_lock(&trace_types_lock);

	if (iter->trace->pipe_close)
		iter->trace->pipe_close(iter);

	mutex_unlock(&trace_types_lock);

	free_cpumask_var(iter->started);
	mutex_destroy(&iter->mutex);
	kfree(iter->trace);
	kfree(iter);

	trace_array_put(tr);

	return 0;
}

static unsigned int
trace_poll(struct trace_iterator *iter, struct file *filp, poll_table *poll_table)
{
	/* Iterators are static, they should be filled or empty */
	if (trace_buffer_iter(iter, iter->cpu_file))
		return POLLIN | POLLRDNORM;

	if (trace_flags & TRACE_ITER_BLOCK)
		/*
		 * Always select as readable when in blocking mode
		 */
		return POLLIN | POLLRDNORM;
	else
		return ring_buffer_poll_wait(iter->trace_buffer->buffer, iter->cpu_file,
					     filp, poll_table);
}

static unsigned int
tracing_poll_pipe(struct file *filp, poll_table *poll_table)
{
	struct trace_iterator *iter = filp->private_data;

	return trace_poll(iter, filp, poll_table);
}

/*
 * This is a make-shift waitqueue.
 * A tracer might use this callback on some rare cases:
 *
 *  1) the current tracer might hold the runqueue lock when it wakes up
 *     a reader, hence a deadlock (sched, function, and function graph tracers)
 *  2) the function tracers, trace all functions, we don't want
 *     the overhead of calling wake_up and friends
 *     (and tracing them too)
 *
 *     Anyway, this is really very primitive wakeup.
 */
void poll_wait_pipe(struct trace_iterator *iter)
{
	set_current_state(TASK_INTERRUPTIBLE);
	/* sleep for 100 msecs, and try again. */
	schedule_timeout(HZ / 10);
}

/* Must be called with trace_types_lock mutex held. */
static int tracing_wait_pipe(struct file *filp)
{
	struct trace_iterator *iter = filp->private_data;

	while (trace_empty(iter)) {

		if ((filp->f_flags & O_NONBLOCK)) {
			return -EAGAIN;
		}

		mutex_unlock(&iter->mutex);

		iter->trace->wait_pipe(iter);

		mutex_lock(&iter->mutex);

		if (signal_pending(current))
			return -EINTR;

		/*
		 * We block until we read something and tracing is disabled.
		 * We still block if tracing is disabled, but we have never
		 * read anything. This allows a user to cat this file, and
		 * then enable tracing. But after we have read something,
		 * we give an EOF when tracing is again disabled.
		 *
		 * iter->pos will be 0 if we haven't read anything.
		 */
		if (!tracing_is_on() && iter->pos)
			break;
	}

	return 1;
}

/*
 * Consumer reader.
 */
static ssize_t
tracing_read_pipe(struct file *filp, char __user *ubuf,
		  size_t cnt, loff_t *ppos)
{
	struct trace_iterator *iter = filp->private_data;
	struct trace_array *tr = iter->tr;
	ssize_t sret;

	/* return any leftover data */
	sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
	if (sret != -EBUSY)
		return sret;

	trace_seq_init(&iter->seq);

	/* copy the tracer to avoid using a global lock all around */
	mutex_lock(&trace_types_lock);
	if (unlikely(iter->trace->name != tr->current_trace->name))
		*iter->trace = *tr->current_trace;
	mutex_unlock(&trace_types_lock);

	/*
	 * Avoid more than one consumer on a single file descriptor
	 * This is just a matter of traces coherency, the ring buffer itself
	 * is protected.
	 */
	mutex_lock(&iter->mutex);
	if (iter->trace->read) {
		sret = iter->trace->read(iter, filp, ubuf, cnt, ppos);
		if (sret)
			goto out;
	}

waitagain:
	sret = tracing_wait_pipe(filp);
	if (sret <= 0)
		goto out;

	/* stop when tracing is finished */
	if (trace_empty(iter)) {
		sret = 0;
		goto out;
	}

	if (cnt >= PAGE_SIZE)
		cnt = PAGE_SIZE - 1;

	/* reset all but tr, trace, and overruns */
	memset(&iter->seq, 0,
	       sizeof(struct trace_iterator) -
	       offsetof(struct trace_iterator, seq));
	cpumask_clear(iter->started);
	iter->pos = -1;

	trace_event_read_lock();
	trace_access_lock(iter->cpu_file);
	while (trace_find_next_entry_inc(iter) != NULL) {
		enum print_line_t ret;
		int len = iter->seq.len;

		ret = print_trace_line(iter);
		if (ret == TRACE_TYPE_PARTIAL_LINE) {
			/* don't print partial lines */
			iter->seq.len = len;
			break;
		}
		if (ret != TRACE_TYPE_NO_CONSUME)
			trace_consume(iter);

		if (iter->seq.len >= cnt)
			break;

		/*
		 * Setting the full flag means we reached the trace_seq buffer
		 * size and we should leave by partial output condition above.
		 * One of the trace_seq_* functions is not used properly.
		 */
		WARN_ONCE(iter->seq.full, "full flag set for trace type %d",
			  iter->ent->type);
	}
	trace_access_unlock(iter->cpu_file);
	trace_event_read_unlock();

	/* Now copy what we have to the user */
	sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
	if (iter->seq.readpos >= iter->seq.len)
		trace_seq_init(&iter->seq);

	/*
	 * If there was nothing to send to user, in spite of consuming trace
	 * entries, go back to wait for more entries.
	 */
	if (sret == -EBUSY)
		goto waitagain;

out:
	mutex_unlock(&iter->mutex);

	return sret;
}

static void tracing_pipe_buf_release(struct pipe_inode_info *pipe,
				     struct pipe_buffer *buf)
{
	__free_page(buf->page);
}

static void tracing_spd_release_pipe(struct splice_pipe_desc *spd,
				     unsigned int idx)
{
	__free_page(spd->pages[idx]);
}

static const struct pipe_buf_operations tracing_pipe_buf_ops = {
	.can_merge		= 0,
	.map			= generic_pipe_buf_map,
	.unmap			= generic_pipe_buf_unmap,
	.confirm		= generic_pipe_buf_confirm,
	.release		= tracing_pipe_buf_release,
	.steal			= generic_pipe_buf_steal,
	.get			= generic_pipe_buf_get,
};

static size_t
tracing_fill_pipe_page(size_t rem, struct trace_iterator *iter)
{
	size_t count;
	int ret;

	/* Seq buffer is page-sized, exactly what we need. */
	for (;;) {
		count = iter->seq.len;
		ret = print_trace_line(iter);
		count = iter->seq.len - count;
		if (rem < count) {
			rem = 0;
			iter->seq.len -= count;
			break;
		}
		if (ret == TRACE_TYPE_PARTIAL_LINE) {
			iter->seq.len -= count;
			break;
		}

		if (ret != TRACE_TYPE_NO_CONSUME)
			trace_consume(iter);
		rem -= count;
		if (!trace_find_next_entry_inc(iter))	{
			rem = 0;
			iter->ent = NULL;
			break;
		}
	}

	return rem;
}

static ssize_t tracing_splice_read_pipe(struct file *filp,
					loff_t *ppos,
					struct pipe_inode_info *pipe,
					size_t len,
					unsigned int flags)
{
	struct page *pages_def[PIPE_DEF_BUFFERS];
	struct partial_page partial_def[PIPE_DEF_BUFFERS];
	struct trace_iterator *iter = filp->private_data;
	struct splice_pipe_desc spd = {
		.pages		= pages_def,
		.partial	= partial_def,
		.nr_pages	= 0, /* This gets updated below. */
		.nr_pages_max	= PIPE_DEF_BUFFERS,
		.flags		= flags,
		.ops		= &tracing_pipe_buf_ops,
		.spd_release	= tracing_spd_release_pipe,
	};
	struct trace_array *tr = iter->tr;
	ssize_t ret;
	size_t rem;
	unsigned int i;

	if (splice_grow_spd(pipe, &spd))
		return -ENOMEM;

	/* copy the tracer to avoid using a global lock all around */
	mutex_lock(&trace_types_lock);
	if (unlikely(iter->trace->name != tr->current_trace->name))
		*iter->trace = *tr->current_trace;
	mutex_unlock(&trace_types_lock);

	mutex_lock(&iter->mutex);

	if (iter->trace->splice_read) {
		ret = iter->trace->splice_read(iter, filp,
					       ppos, pipe, len, flags);
		if (ret)
			goto out_err;
	}

	ret = tracing_wait_pipe(filp);
	if (ret <= 0)
		goto out_err;

	if (!iter->ent && !trace_find_next_entry_inc(iter)) {
		ret = -EFAULT;
		goto out_err;
	}

	trace_event_read_lock();
	trace_access_lock(iter->cpu_file);

	/* Fill as many pages as possible. */
	for (i = 0, rem = len; i < pipe->buffers && rem; i++) {
		spd.pages[i] = alloc_page(GFP_KERNEL);
		if (!spd.pages[i])
			break;

		rem = tracing_fill_pipe_page(rem, iter);

		/* Copy the data into the page, so we can start over. */
		ret = trace_seq_to_buffer(&iter->seq,
					  page_address(spd.pages[i]),
					  iter->seq.len);
		if (ret < 0) {
			__free_page(spd.pages[i]);
			break;
		}
		spd.partial[i].offset = 0;
		spd.partial[i].len = iter->seq.len;

		trace_seq_init(&iter->seq);
	}

	trace_access_unlock(iter->cpu_file);
	trace_event_read_unlock();
	mutex_unlock(&iter->mutex);

	spd.nr_pages = i;

	ret = splice_to_pipe(pipe, &spd);
out:
	splice_shrink_spd(&spd);
	return ret;

out_err:
	mutex_unlock(&iter->mutex);
	goto out;
}

static ssize_t
tracing_entries_read(struct file *filp, char __user *ubuf,
		     size_t cnt, loff_t *ppos)
{
	struct inode *inode = file_inode(filp);
	struct trace_array *tr = inode->i_private;
	int cpu = tracing_get_cpu(inode);
	char buf[64];
	int r = 0;
	ssize_t ret;

	mutex_lock(&trace_types_lock);

	if (cpu == RING_BUFFER_ALL_CPUS) {
		int cpu, buf_size_same;
		unsigned long size;

		size = 0;
		buf_size_same = 1;
		/* check if all cpu sizes are same */
		for_each_tracing_cpu(cpu) {
			/* fill in the size from first enabled cpu */
			if (size == 0)
				size = per_cpu_ptr(tr->trace_buffer.data, cpu)->entries;
			if (size != per_cpu_ptr(tr->trace_buffer.data, cpu)->entries) {
				buf_size_same = 0;
				break;
			}
		}

		if (buf_size_same) {
			if (!ring_buffer_expanded)
				r = sprintf(buf, "%lu (expanded: %lu)\n",
					    size >> 10,
					    trace_buf_size >> 10);
			else
				r = sprintf(buf, "%lu\n", size >> 10);
		} else
			r = sprintf(buf, "X\n");
	} else
		r = sprintf(buf, "%lu\n", per_cpu_ptr(tr->trace_buffer.data, cpu)->entries >> 10);

	mutex_unlock(&trace_types_lock);

	ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
	return ret;
}

static ssize_t
tracing_entries_write(struct file *filp, const char __user *ubuf,
		      size_t cnt, loff_t *ppos)
{
	struct inode *inode = file_inode(filp);
	struct trace_array *tr = inode->i_private;
	unsigned long val;
	int ret;

	ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
	if (ret)
		return ret;

	/* must have at least 1 entry */
	if (!val)
		return -EINVAL;

	/* value is in KB */
	val <<= 10;
	ret = tracing_resize_ring_buffer(tr, val, tracing_get_cpu(inode));
	if (ret < 0)
		return ret;

	*ppos += cnt;

	return cnt;
}

static ssize_t
tracing_total_entries_read(struct file *filp, char __user *ubuf,
				size_t cnt, loff_t *ppos)
{
	struct trace_array *tr = filp->private_data;
	char buf[64];
	int r, cpu;
	unsigned long size = 0, expanded_size = 0;

	mutex_lock(&trace_types_lock);
	for_each_tracing_cpu(cpu) {
		size += per_cpu_ptr(tr->trace_buffer.data, cpu)->entries >> 10;
		if (!ring_buffer_expanded)
			expanded_size += trace_buf_size >> 10;
	}
	if (ring_buffer_expanded)
		r = sprintf(buf, "%lu\n", size);
	else
		r = sprintf(buf, "%lu (expanded: %lu)\n", size, expanded_size);
	mutex_unlock(&trace_types_lock);

	return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
}

static ssize_t
tracing_free_buffer_write(struct file *filp, const char __user *ubuf,
			  size_t cnt, loff_t *ppos)
{
	/*
	 * There is no need to read what the user has written, this function
	 * is just to make sure that there is no error when "echo" is used
	 */

	*ppos += cnt;

	return cnt;
}

static int
tracing_free_buffer_release(struct inode *inode, struct file *filp)
{
	struct trace_array *tr = inode->i_private;

	/* disable tracing ? */
	if (trace_flags & TRACE_ITER_STOP_ON_FREE)
		tracer_tracing_off(tr);
	/* resize the ring buffer to 0 */
	tracing_resize_ring_buffer(tr, 0, RING_BUFFER_ALL_CPUS);

	trace_array_put(tr);

	return 0;
}

static ssize_t
tracing_mark_write(struct file *filp, const char __user *ubuf,
					size_t cnt, loff_t *fpos)
{
	unsigned long addr = (unsigned long)ubuf;
	struct trace_array *tr = filp->private_data;
	struct ring_buffer_event *event;
	struct ring_buffer *buffer;
	struct print_entry *entry;
	unsigned long irq_flags;
	struct page *pages[2];
	void *map_page[2];
	int nr_pages = 1;
	ssize_t written;
	int offset;
	int size;
	int len;
	int ret;
	int i;

	if (tracing_disabled)
		return -EINVAL;

	if (!(trace_flags & TRACE_ITER_MARKERS))
		return -EINVAL;

	if (cnt > TRACE_BUF_SIZE)
		cnt = TRACE_BUF_SIZE;

	/*
	 * Userspace is injecting traces into the kernel trace buffer.
	 * We want to be as non intrusive as possible.
	 * To do so, we do not want to allocate any special buffers
	 * or take any locks, but instead write the userspace data
	 * straight into the ring buffer.
	 *
	 * First we need to pin the userspace buffer into memory,
	 * which, most likely it is, because it just referenced it.
	 * But there's no guarantee that it is. By using get_user_pages_fast()
	 * and kmap_atomic/kunmap_atomic() we can get access to the
	 * pages directly. We then write the data directly into the
	 * ring buffer.
	 */
	BUILD_BUG_ON(TRACE_BUF_SIZE >= PAGE_SIZE);

	/* check if we cross pages */
	if ((addr & PAGE_MASK) != ((addr + cnt) & PAGE_MASK))
		nr_pages = 2;

	offset = addr & (PAGE_SIZE - 1);
	addr &= PAGE_MASK;

	ret = get_user_pages_fast(addr, nr_pages, 0, pages);
	if (ret < nr_pages) {
		while (--ret >= 0)
			put_page(pages[ret]);
		written = -EFAULT;
		goto out;
	}

	for (i = 0; i < nr_pages; i++)
		map_page[i] = kmap_atomic(pages[i]);

	local_save_flags(irq_flags);
	size = sizeof(*entry) + cnt + 2; /* possible \n added */
	buffer = tr->trace_buffer.buffer;
	event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, size,
					  irq_flags, preempt_count());
	if (!event) {
		/* Ring buffer disabled, return as if not open for write */
		written = -EBADF;
		goto out_unlock;
	}

	entry = ring_buffer_event_data(event);
	entry->ip = _THIS_IP_;

	if (nr_pages == 2) {
		len = PAGE_SIZE - offset;
		memcpy(&entry->buf, map_page[0] + offset, len);
		memcpy(&entry->buf[len], map_page[1], cnt - len);
	} else
		memcpy(&entry->buf, map_page[0] + offset, cnt);

	if (entry->buf[cnt - 1] != '\n') {
		entry->buf[cnt] = '\n';
		entry->buf[cnt + 1] = '\0';
	} else
		entry->buf[cnt] = '\0';

	__buffer_unlock_commit(buffer, event);

	written = cnt;

	*fpos += written;

 out_unlock:
	for (i = 0; i < nr_pages; i++){
		kunmap_atomic(map_page[i]);
		put_page(pages[i]);
	}
 out:
	return written;
}

static int tracing_clock_show(struct seq_file *m, void *v)
{
	struct trace_array *tr = m->private;
	int i;

	for (i = 0; i < ARRAY_SIZE(trace_clocks); i++)
		seq_printf(m,
			"%s%s%s%s", i ? " " : "",
			i == tr->clock_id ? "[" : "", trace_clocks[i].name,
			i == tr->clock_id ? "]" : "");
	seq_putc(m, '\n');

	return 0;
}

static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf,
				   size_t cnt, loff_t *fpos)
{
	struct seq_file *m = filp->private_data;
	struct trace_array *tr = m->private;
	char buf[64];
	const char *clockstr;
	int i;

	if (cnt >= sizeof(buf))
		return -EINVAL;

	if (copy_from_user(&buf, ubuf, cnt))
		return -EFAULT;

	buf[cnt] = 0;

	clockstr = strstrip(buf);

	for (i = 0; i < ARRAY_SIZE(trace_clocks); i++) {
		if (strcmp(trace_clocks[i].name, clockstr) == 0)
			break;
	}
	if (i == ARRAY_SIZE(trace_clocks))
		return -EINVAL;

	mutex_lock(&trace_types_lock);

	tr->clock_id = i;

	ring_buffer_set_clock(tr->trace_buffer.buffer, trace_clocks[i].func);

	/*
	 * New clock may not be consistent with the previous clock.
	 * Reset the buffer so that it doesn't have incomparable timestamps.
	 */
	tracing_reset_online_cpus(&tr->trace_buffer);

#ifdef CONFIG_TRACER_MAX_TRACE
	if (tr->flags & TRACE_ARRAY_FL_GLOBAL && tr->max_buffer.buffer)
		ring_buffer_set_clock(tr->max_buffer.buffer, trace_clocks[i].func);
	tracing_reset_online_cpus(&tr->max_buffer);
#endif

	mutex_unlock(&trace_types_lock);

	*fpos += cnt;

	return cnt;
}

static int tracing_clock_open(struct inode *inode, struct file *file)
{
	struct trace_array *tr = inode->i_private;
	int ret;

	if (tracing_disabled)
		return -ENODEV;

	if (trace_array_get(tr))
		return -ENODEV;

	ret = single_open(file, tracing_clock_show, inode->i_private);
	if (ret < 0)
		trace_array_put(tr);

	return ret;
}

struct ftrace_buffer_info {
	struct trace_iterator	iter;
	void			*spare;
	unsigned int		read;
};

#ifdef CONFIG_TRACER_SNAPSHOT
static int tracing_snapshot_open(struct inode *inode, struct file *file)
{
	struct trace_array *tr = inode->i_private;
	struct trace_iterator *iter;
	struct seq_file *m;
	int ret = 0;

	if (trace_array_get(tr) < 0)
		return -ENODEV;

	if (file->f_mode & FMODE_READ) {
		iter = __tracing_open(inode, file, true);
		if (IS_ERR(iter))
			ret = PTR_ERR(iter);
	} else {
		/* Writes still need the seq_file to hold the private data */
		ret = -ENOMEM;
		m = kzalloc(sizeof(*m), GFP_KERNEL);
		if (!m)
			goto out;
		iter = kzalloc(sizeof(*iter), GFP_KERNEL);
		if (!iter) {
			kfree(m);
			goto out;
		}
		ret = 0;

		iter->tr = tr;
		iter->trace_buffer = &tr->max_buffer;
		iter->cpu_file = tracing_get_cpu(inode);
		m->private = iter;
		file->private_data = m;
	}
out:
	if (ret < 0)
		trace_array_put(tr);

	return ret;
}

static ssize_t
tracing_snapshot_write(struct file *filp, const char __user *ubuf, size_t cnt,
		       loff_t *ppos)
{
	struct seq_file *m = filp->private_data;
	struct trace_iterator *iter = m->private;
	struct trace_array *tr = iter->tr;
	unsigned long val;
	int ret;

	ret = tracing_update_buffers();
	if (ret < 0)
		return ret;

	ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
	if (ret)
		return ret;

	mutex_lock(&trace_types_lock);

	if (tr->current_trace->use_max_tr) {
		ret = -EBUSY;
		goto out;
	}

	switch (val) {
	case 0:
		if (iter->cpu_file != RING_BUFFER_ALL_CPUS) {
			ret = -EINVAL;
			break;
		}
		if (tr->allocated_snapshot)
			free_snapshot(tr);
		break;
	case 1:
/* Only allow per-cpu swap if the ring buffer supports it */
#ifndef CONFIG_RING_BUFFER_ALLOW_SWAP
		if (iter->cpu_file != RING_BUFFER_ALL_CPUS) {
			ret = -EINVAL;
			break;
		}
#endif
		if (!tr->allocated_snapshot) {
			ret = alloc_snapshot(tr);
			if (ret < 0)
				break;
		}
		local_irq_disable();
		/* Now, we're going to swap */
		if (iter->cpu_file == RING_BUFFER_ALL_CPUS)
			update_max_tr(tr, current, smp_processor_id());
		else
			update_max_tr_single(tr, current, iter->cpu_file);
		local_irq_enable();
		break;
	default:
		if (tr->allocated_snapshot) {
			if (iter->cpu_file == RING_BUFFER_ALL_CPUS)
				tracing_reset_online_cpus(&tr->max_buffer);
			else
				tracing_reset(&tr->max_buffer, iter->cpu_file);
		}
		break;
	}

	if (ret >= 0) {
		*ppos += cnt;
		ret = cnt;
	}
out:
	mutex_unlock(&trace_types_lock);
	return ret;
}

static int tracing_snapshot_release(struct inode *inode, struct file *file)
{
	struct seq_file *m = file->private_data;
	int ret;

	ret = tracing_release(inode, file);

	if (file->f_mode & FMODE_READ)
		return ret;

	/* If write only, the seq_file is just a stub */
	if (m)
		kfree(m->private);
	kfree(m);

	return 0;
}

static int tracing_buffers_open(struct inode *inode, struct file *filp);
static ssize_t tracing_buffers_read(struct file *filp, char __user *ubuf,
				    size_t count, loff_t *ppos);
static int tracing_buffers_release(struct inode *inode, struct file *file);
static ssize_t tracing_buffers_splice_read(struct file *file, loff_t *ppos,
		   struct pipe_inode_info *pipe, size_t len, unsigned int flags);

static int snapshot_raw_open(struct inode *inode, struct file *filp)
{
	struct ftrace_buffer_info *info;
	int ret;

	ret = tracing_buffers_open(inode, filp);
	if (ret < 0)
		return ret;

	info = filp->private_data;

	if (info->iter.trace->use_max_tr) {
		tracing_buffers_release(inode, filp);
		return -EBUSY;
	}

	info->iter.snapshot = true;
	info->iter.trace_buffer = &info->iter.tr->max_buffer;

	return ret;
}

#endif /* CONFIG_TRACER_SNAPSHOT */


static const struct file_operations tracing_max_lat_fops = {
	.open		= tracing_open_generic,
	.read		= tracing_max_lat_read,
	.write		= tracing_max_lat_write,
	.llseek		= generic_file_llseek,
};

static const struct file_operations set_tracer_fops = {
	.open		= tracing_open_generic,
	.read		= tracing_set_trace_read,
	.write		= tracing_set_trace_write,
	.llseek		= generic_file_llseek,
};

static const struct file_operations tracing_pipe_fops = {
	.open		= tracing_open_pipe,
	.poll		= tracing_poll_pipe,
	.read		= tracing_read_pipe,
	.splice_read	= tracing_splice_read_pipe,
	.release	= tracing_release_pipe,
	.llseek		= no_llseek,
};

static const struct file_operations tracing_entries_fops = {
	.open		= tracing_open_generic_tr,
	.read		= tracing_entries_read,
	.write		= tracing_entries_write,
	.llseek		= generic_file_llseek,
	.release	= tracing_release_generic_tr,
};

static const struct file_operations tracing_total_entries_fops = {
	.open		= tracing_open_generic_tr,
	.read		= tracing_total_entries_read,
	.llseek		= generic_file_llseek,
	.release	= tracing_release_generic_tr,
};

static const struct file_operations tracing_free_buffer_fops = {
	.open		= tracing_open_generic_tr,
	.write		= tracing_free_buffer_write,
	.release	= tracing_free_buffer_release,
};

static const struct file_operations tracing_mark_fops = {
	.open		= tracing_open_generic_tr,
	.write		= tracing_mark_write,
	.llseek		= generic_file_llseek,
	.release	= tracing_release_generic_tr,
};

static const struct file_operations trace_clock_fops = {
	.open		= tracing_clock_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= tracing_single_release_tr,
	.write		= tracing_clock_write,
};

#ifdef CONFIG_TRACER_SNAPSHOT
static const struct file_operations snapshot_fops = {
	.open		= tracing_snapshot_open,
	.read		= seq_read,
	.write		= tracing_snapshot_write,
	.llseek		= tracing_seek,
	.release	= tracing_snapshot_release,
};

static const struct file_operations snapshot_raw_fops = {
	.open		= snapshot_raw_open,
	.read		= tracing_buffers_read,
	.release	= tracing_buffers_release,
	.splice_read	= tracing_buffers_splice_read,
	.llseek		= no_llseek,
};

#endif /* CONFIG_TRACER_SNAPSHOT */

static int tracing_buffers_open(struct inode *inode, struct file *filp)
{
	struct trace_array *tr = inode->i_private;
	struct ftrace_buffer_info *info;
	int ret;

	if (tracing_disabled)
		return -ENODEV;

	if (trace_array_get(tr) < 0)
		return -ENODEV;

	info = kzalloc(sizeof(*info), GFP_KERNEL);
	if (!info) {
		trace_array_put(tr);
		return -ENOMEM;
	}

	mutex_lock(&trace_types_lock);

	info->iter.tr		= tr;
	info->iter.cpu_file	= tracing_get_cpu(inode);
	info->iter.trace	= tr->current_trace;
	info->iter.trace_buffer = &tr->trace_buffer;
	info->spare		= NULL;
	/* Force reading ring buffer for first read */
	info->read		= (unsigned int)-1;

	filp->private_data = info;

	mutex_unlock(&trace_types_lock);

	ret = nonseekable_open(inode, filp);
	if (ret < 0)
		trace_array_put(tr);

	return ret;
}

static unsigned int
tracing_buffers_poll(struct file *filp, poll_table *poll_table)
{
	struct ftrace_buffer_info *info = filp->private_data;
	struct trace_iterator *iter = &info->iter;

	return trace_poll(iter, filp, poll_table);
}

static ssize_t
tracing_buffers_read(struct file *filp, char __user *ubuf,
		     size_t count, loff_t *ppos)
{
	struct ftrace_buffer_info *info = filp->private_data;
	struct trace_iterator *iter = &info->iter;
	ssize_t ret;
	ssize_t size;

	if (!count)
		return 0;

	mutex_lock(&trace_types_lock);

#ifdef CONFIG_TRACER_MAX_TRACE
	if (iter->snapshot && iter->tr->current_trace->use_max_tr) {
		size = -EBUSY;
		goto out_unlock;
	}
#endif

	if (!info->spare)
		info->spare = ring_buffer_alloc_read_page(iter->trace_buffer->buffer,
							  iter->cpu_file);
	size = -ENOMEM;
	if (!info->spare)
		goto out_unlock;

	/* Do we have previous read data to read? */
	if (info->read < PAGE_SIZE)
		goto read;

 again:
	trace_access_lock(iter->cpu_file);
	ret = ring_buffer_read_page(iter->trace_buffer->buffer,
				    &info->spare,
				    count,
				    iter->cpu_file, 0);
	trace_access_unlock(iter->cpu_file);

	if (ret < 0) {
		if (trace_empty(iter)) {
			if ((filp->f_flags & O_NONBLOCK)) {
				size = -EAGAIN;
				goto out_unlock;
			}
			mutex_unlock(&trace_types_lock);
			iter->trace->wait_pipe(iter);
			mutex_lock(&trace_types_lock);
			if (signal_pending(current)) {
				size = -EINTR;
				goto out_unlock;
			}
			goto again;
		}
		size = 0;
		goto out_unlock;
	}

	info->read = 0;
 read:
	size = PAGE_SIZE - info->read;
	if (size > count)
		size = count;

	ret = copy_to_user(ubuf, info->spare + info->read, size);
	if (ret == size) {
		size = -EFAULT;
		goto out_unlock;
	}
	size -= ret;

	*ppos += size;
	info->read += size;

 out_unlock:
	mutex_unlock(&trace_types_lock);

	return size;
}

static int tracing_buffers_release(struct inode *inode, struct file *file)
{
	struct ftrace_buffer_info *info = file->private_data;
	struct trace_iterator *iter = &info->iter;

	mutex_lock(&trace_types_lock);

	__trace_array_put(iter->tr);

	if (info->spare)
		ring_buffer_free_read_page(iter->trace_buffer->buffer, info->spare);
	kfree(info);

	mutex_unlock(&trace_types_lock);

	return 0;
}

struct buffer_ref {
	struct ring_buffer	*buffer;
	void			*page;
	int			ref;
};

static void buffer_pipe_buf_release(struct pipe_inode_info *pipe,
				    struct pipe_buffer *buf)
{
	struct buffer_ref *ref = (struct buffer_ref *)buf->private;

	if (--ref->ref)
		return;

	ring_buffer_free_read_page(ref->buffer, ref->page);
	kfree(ref);
	buf->private = 0;
}

static void buffer_pipe_buf_get(struct pipe_inode_info *pipe,
				struct pipe_buffer *buf)
{
	struct buffer_ref *ref = (struct buffer_ref *)buf->private;

	ref->ref++;
}

/* Pipe buffer operations for a buffer. */
static const struct pipe_buf_operations buffer_pipe_buf_ops = {
	.can_merge		= 0,
	.map			= generic_pipe_buf_map,
	.unmap			= generic_pipe_buf_unmap,
	.confirm		= generic_pipe_buf_confirm,
	.release		= buffer_pipe_buf_release,
	.steal			= generic_pipe_buf_steal,
	.get			= buffer_pipe_buf_get,
};

/*
 * Callback from splice_to_pipe(), if we need to release some pages
 * at the end of the spd in case we error'ed out in filling the pipe.
 */
static void buffer_spd_release(struct splice_pipe_desc *spd, unsigned int i)
{
	struct buffer_ref *ref =
		(struct buffer_ref *)spd->partial[i].private;

	if (--ref->ref)
		return;

	ring_buffer_free_read_page(ref->buffer, ref->page);
	kfree(ref);
	spd->partial[i].private = 0;
}

static ssize_t
tracing_buffers_splice_read(struct file *file, loff_t *ppos,
			    struct pipe_inode_info *pipe, size_t len,
			    unsigned int flags)
{
	struct ftrace_buffer_info *info = file->private_data;
	struct trace_iterator *iter = &info->iter;
	struct partial_page partial_def[PIPE_DEF_BUFFERS];
	struct page *pages_def[PIPE_DEF_BUFFERS];
	struct splice_pipe_desc spd = {
		.pages		= pages_def,
		.partial	= partial_def,
		.nr_pages_max	= PIPE_DEF_BUFFERS,
		.flags		= flags,
		.ops		= &buffer_pipe_buf_ops,
		.spd_release	= buffer_spd_release,
	};
	struct buffer_ref *ref;
	int entries, size, i;
	ssize_t ret;

	mutex_lock(&trace_types_lock);

#ifdef CONFIG_TRACER_MAX_TRACE
	if (iter->snapshot && iter->tr->current_trace->use_max_tr) {
		ret = -EBUSY;
		goto out;
	}
#endif

	if (splice_grow_spd(pipe, &spd)) {
		ret = -ENOMEM;
		goto out;
	}

	if (*ppos & (PAGE_SIZE - 1)) {
		ret = -EINVAL;
		goto out;
	}

	if (len & (PAGE_SIZE - 1)) {
		if (len < PAGE_SIZE) {
			ret = -EINVAL;
			goto out;
		}
		len &= PAGE_MASK;
	}

 again:
	trace_access_lock(iter->cpu_file);
	entries = ring_buffer_entries_cpu(iter->trace_buffer->buffer, iter->cpu_file);

	for (i = 0; i < pipe->buffers && len && entries; i++, len -= PAGE_SIZE) {
		struct page *page;
		int r;

		ref = kzalloc(sizeof(*ref), GFP_KERNEL);
		if (!ref)
			break;

		ref->ref = 1;
		ref->buffer = iter->trace_buffer->buffer;
		ref->page = ring_buffer_alloc_read_page(ref->buffer, iter->cpu_file);
		if (!ref->page) {
			kfree(ref);
			break;
		}

		r = ring_buffer_read_page(ref->buffer, &ref->page,
					  len, iter->cpu_file, 1);
		if (r < 0) {
			ring_buffer_free_read_page(ref->buffer, ref->page);
			kfree(ref);
			break;
		}

		/*
		 * zero out any left over data, this is going to
		 * user land.
		 */
		size = ring_buffer_page_len(ref->page);
		if (size < PAGE_SIZE)
			memset(ref->page + size, 0, PAGE_SIZE - size);

		page = virt_to_page(ref->page);

		spd.pages[i] = page;
		spd.partial[i].len = PAGE_SIZE;
		spd.partial[i].offset = 0;
		spd.partial[i].private = (unsigned long)ref;
		spd.nr_pages++;
		*ppos += PAGE_SIZE;

		entries = ring_buffer_entries_cpu(iter->trace_buffer->buffer, iter->cpu_file);
	}

	trace_access_unlock(iter->cpu_file);
	spd.nr_pages = i;

	/* did we read anything? */
	if (!spd.nr_pages) {
		if ((file->f_flags & O_NONBLOCK) || (flags & SPLICE_F_NONBLOCK)) {
			ret = -EAGAIN;
			goto out;
		}
		mutex_unlock(&trace_types_lock);
		iter->trace->wait_pipe(iter);
		mutex_lock(&trace_types_lock);
		if (signal_pending(current)) {
			ret = -EINTR;
			goto out;
		}
		goto again;
	}

	ret = splice_to_pipe(pipe, &spd);
	splice_shrink_spd(&spd);
out:
	mutex_unlock(&trace_types_lock);

	return ret;
}

static const struct file_operations tracing_buffers_fops = {
	.open		= tracing_buffers_open,
	.read		= tracing_buffers_read,
	.poll		= tracing_buffers_poll,
	.release	= tracing_buffers_release,
	.splice_read	= tracing_buffers_splice_read,
	.llseek		= no_llseek,
};

static ssize_t
tracing_stats_read(struct file *filp, char __user *ubuf,
		   size_t count, loff_t *ppos)
{
	struct inode *inode = file_inode(filp);
	struct trace_array *tr = inode->i_private;
	struct trace_buffer *trace_buf = &tr->trace_buffer;
	int cpu = tracing_get_cpu(inode);
	struct trace_seq *s;
	unsigned long cnt;
	unsigned long long t;
	unsigned long usec_rem;

	s = kmalloc(sizeof(*s), GFP_KERNEL);
	if (!s)
		return -ENOMEM;

	trace_seq_init(s);

	cnt = ring_buffer_entries_cpu(trace_buf->buffer, cpu);
	trace_seq_printf(s, "entries: %ld\n", cnt);

	cnt = ring_buffer_overrun_cpu(trace_buf->buffer, cpu);
	trace_seq_printf(s, "overrun: %ld\n", cnt);

	cnt = ring_buffer_commit_overrun_cpu(trace_buf->buffer, cpu);
	trace_seq_printf(s, "commit overrun: %ld\n", cnt);

	cnt = ring_buffer_bytes_cpu(trace_buf->buffer, cpu);
	trace_seq_printf(s, "bytes: %ld\n", cnt);

	if (trace_clocks[tr->clock_id].in_ns) {
		/* local or global for trace_clock */
		t = ns2usecs(ring_buffer_oldest_event_ts(trace_buf->buffer, cpu));
		usec_rem = do_div(t, USEC_PER_SEC);
		trace_seq_printf(s, "oldest event ts: %5llu.%06lu\n",
								t, usec_rem);

		t = ns2usecs(ring_buffer_time_stamp(trace_buf->buffer, cpu));
		usec_rem = do_div(t, USEC_PER_SEC);
		trace_seq_printf(s, "now ts: %5llu.%06lu\n", t, usec_rem);
	} else {
		/* counter or tsc mode for trace_clock */
		trace_seq_printf(s, "oldest event ts: %llu\n",
				ring_buffer_oldest_event_ts(trace_buf->buffer, cpu));

		trace_seq_printf(s, "now ts: %llu\n",
				ring_buffer_time_stamp(trace_buf->buffer, cpu));
	}

	cnt = ring_buffer_dropped_events_cpu(trace_buf->buffer, cpu);
	trace_seq_printf(s, "dropped events: %ld\n", cnt);

	cnt = ring_buffer_read_events_cpu(trace_buf->buffer, cpu);
	trace_seq_printf(s, "read events: %ld\n", cnt);

	count = simple_read_from_buffer(ubuf, count, ppos, s->buffer, s->len);

	kfree(s);

	return count;
}

static const struct file_operations tracing_stats_fops = {
	.open		= tracing_open_generic_tr,
	.read		= tracing_stats_read,
	.llseek		= generic_file_llseek,
	.release	= tracing_release_generic_tr,
};

#ifdef CONFIG_DYNAMIC_FTRACE

int __weak ftrace_arch_read_dyn_info(char *buf, int size)
{
	return 0;
}

static ssize_t
tracing_read_dyn_info(struct file *filp, char __user *ubuf,
		  size_t cnt, loff_t *ppos)
{
	static char ftrace_dyn_info_buffer[1024];
	static DEFINE_MUTEX(dyn_info_mutex);
	unsigned long *p = filp->private_data;
	char *buf = ftrace_dyn_info_buffer;
	int size = ARRAY_SIZE(ftrace_dyn_info_buffer);
	int r;

	mutex_lock(&dyn_info_mutex);
	r = sprintf(buf, "%ld ", *p);

	r += ftrace_arch_read_dyn_info(buf+r, (size-1)-r);
	buf[r++] = '\n';

	r = simple_read_from_buffer(ubuf, cnt, ppos, buf, r);

	mutex_unlock(&dyn_info_mutex);

	return r;
}

static const struct file_operations tracing_dyn_info_fops = {
	.open		= tracing_open_generic,
	.read		= tracing_read_dyn_info,
	.llseek		= generic_file_llseek,
};
#endif /* CONFIG_DYNAMIC_FTRACE */

#if defined(CONFIG_TRACER_SNAPSHOT) && defined(CONFIG_DYNAMIC_FTRACE)
static void
ftrace_snapshot(unsigned long ip, unsigned long parent_ip, void **data)
{
	tracing_snapshot();
}

static void
ftrace_count_snapshot(unsigned long ip, unsigned long parent_ip, void **data)
{
	unsigned long *count = (long *)data;

	if (!*count)
		return;

	if (*count != -1)
		(*count)--;

	tracing_snapshot();
}

static int
ftrace_snapshot_print(struct seq_file *m, unsigned long ip,
		      struct ftrace_probe_ops *ops, void *data)
{
	long count = (long)data;

	seq_printf(m, "%ps:", (void *)ip);

	seq_printf(m, "snapshot");

	if (count == -1)
		seq_printf(m, ":unlimited\n");
	else
		seq_printf(m, ":count=%ld\n", count);

	return 0;
}

static struct ftrace_probe_ops snapshot_probe_ops = {
	.func			= ftrace_snapshot,
	.print			= ftrace_snapshot_print,
};

static struct ftrace_probe_ops snapshot_count_probe_ops = {
	.func			= ftrace_count_snapshot,
	.print			= ftrace_snapshot_print,
};

static int
ftrace_trace_snapshot_callback(struct ftrace_hash *hash,
			       char *glob, char *cmd, char *param, int enable)
{
	struct ftrace_probe_ops *ops;
	void *count = (void *)-1;
	char *number;
	int ret;

	/* hash funcs only work with set_ftrace_filter */
	if (!enable)
		return -EINVAL;

	ops = param ? &snapshot_count_probe_ops :  &snapshot_probe_ops;

	if (glob[0] == '!') {
		unregister_ftrace_function_probe_func(glob+1, ops);
		return 0;
	}

	if (!param)
		goto out_reg;

	number = strsep(&param, ":");

	if (!strlen(number))
		goto out_reg;

	/*
	 * We use the callback data field (which is a pointer)
	 * as our counter.
	 */
	ret = kstrtoul(number, 0, (unsigned long *)&count);
	if (ret)
		return ret;

 out_reg:
	ret = register_ftrace_function_probe(glob, ops, count);

	if (ret >= 0)
		alloc_snapshot(&global_trace);

	return ret < 0 ? ret : 0;
}

static struct ftrace_func_command ftrace_snapshot_cmd = {
	.name			= "snapshot",
	.func			= ftrace_trace_snapshot_callback,
};

static int register_snapshot_cmd(void)
{
	return register_ftrace_command(&ftrace_snapshot_cmd);
}
#else
static inline int register_snapshot_cmd(void) { return 0; }
#endif /* defined(CONFIG_TRACER_SNAPSHOT) && defined(CONFIG_DYNAMIC_FTRACE) */

struct dentry *tracing_init_dentry_tr(struct trace_array *tr)
{
	if (tr->dir)
		return tr->dir;

	if (!debugfs_initialized())
		return NULL;

	if (tr->flags & TRACE_ARRAY_FL_GLOBAL)
		tr->dir = debugfs_create_dir("tracing", NULL);

	if (!tr->dir)
		pr_warn_once("Could not create debugfs directory 'tracing'\n");

	return tr->dir;
}

struct dentry *tracing_init_dentry(void)
{
	return tracing_init_dentry_tr(&global_trace);
}

static struct dentry *tracing_dentry_percpu(struct trace_array *tr, int cpu)
{
	struct dentry *d_tracer;

	if (tr->percpu_dir)
		return tr->percpu_dir;

	d_tracer = tracing_init_dentry_tr(tr);
	if (!d_tracer)
		return NULL;

	tr->percpu_dir = debugfs_create_dir("per_cpu", d_tracer);

	WARN_ONCE(!tr->percpu_dir,
		  "Could not create debugfs directory 'per_cpu/%d'\n", cpu);

	return tr->percpu_dir;
}

static struct dentry *
trace_create_cpu_file(const char *name, umode_t mode, struct dentry *parent,
		      void *data, long cpu, const struct file_operations *fops)
{
	struct dentry *ret = trace_create_file(name, mode, parent, data, fops);

	if (ret) /* See tracing_get_cpu() */
		ret->d_inode->i_cdev = (void *)(cpu + 1);
	return ret;
}

static void
tracing_init_debugfs_percpu(struct trace_array *tr, long cpu)
{
	struct dentry *d_percpu = tracing_dentry_percpu(tr, cpu);
	struct dentry *d_cpu;
	char cpu_dir[30]; /* 30 characters should be more than enough */

	if (!d_percpu)
		return;

	snprintf(cpu_dir, 30, "cpu%ld", cpu);
	d_cpu = debugfs_create_dir(cpu_dir, d_percpu);
	if (!d_cpu) {
		pr_warning("Could not create debugfs '%s' entry\n", cpu_dir);
		return;
	}

	/* per cpu trace_pipe */
	trace_create_cpu_file("trace_pipe", 0444, d_cpu,
				tr, cpu, &tracing_pipe_fops);

	/* per cpu trace */
	trace_create_cpu_file("trace", 0644, d_cpu,
				tr, cpu, &tracing_fops);

	trace_create_cpu_file("trace_pipe_raw", 0444, d_cpu,
				tr, cpu, &tracing_buffers_fops);

	trace_create_cpu_file("stats", 0444, d_cpu,
				tr, cpu, &tracing_stats_fops);

	trace_create_cpu_file("buffer_size_kb", 0444, d_cpu,
				tr, cpu, &tracing_entries_fops);

#ifdef CONFIG_TRACER_SNAPSHOT
	trace_create_cpu_file("snapshot", 0644, d_cpu,
				tr, cpu, &snapshot_fops);

	trace_create_cpu_file("snapshot_raw", 0444, d_cpu,
				tr, cpu, &snapshot_raw_fops);
#endif
}

#ifdef CONFIG_FTRACE_SELFTEST
/* Let selftest have access to static functions in this file */
#include "trace_selftest.c"
#endif

struct trace_option_dentry {
	struct tracer_opt		*opt;
	struct tracer_flags		*flags;
	struct trace_array		*tr;
	struct dentry			*entry;
};

static ssize_t
trace_options_read(struct file *filp, char __user *ubuf, size_t cnt,
			loff_t *ppos)
{
	struct trace_option_dentry *topt = filp->private_data;
	char *buf;

	if (topt->flags->val & topt->opt->bit)
		buf = "1\n";
	else
		buf = "0\n";

	return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
}

static ssize_t
trace_options_write(struct file *filp, const char __user *ubuf, size_t cnt,
			 loff_t *ppos)
{
	struct trace_option_dentry *topt = filp->private_data;
	unsigned long val;
	int ret;

	ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
	if (ret)
		return ret;

	if (val != 0 && val != 1)
		return -EINVAL;

	if (!!(topt->flags->val & topt->opt->bit) != val) {
		mutex_lock(&trace_types_lock);
		ret = __set_tracer_option(topt->tr->current_trace, topt->flags,
					  topt->opt, !val);
		mutex_unlock(&trace_types_lock);
		if (ret)
			return ret;
	}

	*ppos += cnt;

	return cnt;
}


static const struct file_operations trace_options_fops = {
	.open = tracing_open_generic,
	.read = trace_options_read,
	.write = trace_options_write,
	.llseek	= generic_file_llseek,
};

static ssize_t
trace_options_core_read(struct file *filp, char __user *ubuf, size_t cnt,
			loff_t *ppos)
{
	long index = (long)filp->private_data;
	char *buf;

	if (trace_flags & (1 << index))
		buf = "1\n";
	else
		buf = "0\n";

	return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
}

static ssize_t
trace_options_core_write(struct file *filp, const char __user *ubuf, size_t cnt,
			 loff_t *ppos)
{
	struct trace_array *tr = &global_trace;
	long index = (long)filp->private_data;
	unsigned long val;
	int ret;

	ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
	if (ret)
		return ret;

	if (val != 0 && val != 1)
		return -EINVAL;

	mutex_lock(&trace_types_lock);
	ret = set_tracer_flag(tr, 1 << index, val);
	mutex_unlock(&trace_types_lock);

	if (ret < 0)
		return ret;

	*ppos += cnt;

	return cnt;
}

static const struct file_operations trace_options_core_fops = {
	.open = tracing_open_generic,
	.read = trace_options_core_read,
	.write = trace_options_core_write,
	.llseek = generic_file_llseek,
};

struct dentry *trace_create_file(const char *name,
				 umode_t mode,
				 struct dentry *parent,
				 void *data,
				 const struct file_operations *fops)
{
	struct dentry *ret;

	ret = debugfs_create_file(name, mode, parent, data, fops);
	if (!ret)
		pr_warning("Could not create debugfs '%s' entry\n", name);

	return ret;
}


static struct dentry *trace_options_init_dentry(struct trace_array *tr)
{
	struct dentry *d_tracer;

	if (tr->options)
		return tr->options;

	d_tracer = tracing_init_dentry_tr(tr);
	if (!d_tracer)
		return NULL;

	tr->options = debugfs_create_dir("options", d_tracer);
	if (!tr->options) {
		pr_warning("Could not create debugfs directory 'options'\n");
		return NULL;
	}

	return tr->options;
}

static void
create_trace_option_file(struct trace_array *tr,
			 struct trace_option_dentry *topt,
			 struct tracer_flags *flags,
			 struct tracer_opt *opt)
{
	struct dentry *t_options;

	t_options = trace_options_init_dentry(tr);
	if (!t_options)
		return;

	topt->flags = flags;
	topt->opt = opt;
	topt->tr = tr;

	topt->entry = trace_create_file(opt->name, 0644, t_options, topt,
				    &trace_options_fops);

}

static struct trace_option_dentry *
create_trace_option_files(struct trace_array *tr, struct tracer *tracer)
{
	struct trace_option_dentry *topts;
	struct tracer_flags *flags;
	struct tracer_opt *opts;
	int cnt;

	if (!tracer)
		return NULL;

	flags = tracer->flags;

	if (!flags || !flags->opts)
		return NULL;

	opts = flags->opts;

	for (cnt = 0; opts[cnt].name; cnt++)
		;

	topts = kcalloc(cnt + 1, sizeof(*topts), GFP_KERNEL);
	if (!topts)
		return NULL;

	for (cnt = 0; opts[cnt].name; cnt++)
		create_trace_option_file(tr, &topts[cnt], flags,
					 &opts[cnt]);

	return topts;
}

static void
destroy_trace_option_files(struct trace_option_dentry *topts)
{
	int cnt;

	if (!topts)
		return;

	for (cnt = 0; topts[cnt].opt; cnt++) {
		if (topts[cnt].entry)
			debugfs_remove(topts[cnt].entry);
	}

	kfree(topts);
}

static struct dentry *
create_trace_option_core_file(struct trace_array *tr,
			      const char *option, long index)
{
	struct dentry *t_options;

	t_options = trace_options_init_dentry(tr);
	if (!t_options)
		return NULL;

	return trace_create_file(option, 0644, t_options, (void *)index,
				    &trace_options_core_fops);
}

static __init void create_trace_options_dir(struct trace_array *tr)
{
	struct dentry *t_options;
	int i;

	t_options = trace_options_init_dentry(tr);
	if (!t_options)
		return;

	for (i = 0; trace_options[i]; i++)
		create_trace_option_core_file(tr, trace_options[i], i);
}

static ssize_t
rb_simple_read(struct file *filp, char __user *ubuf,
	       size_t cnt, loff_t *ppos)
{
	struct trace_array *tr = filp->private_data;
	char buf[64];
	int r;

	r = tracer_tracing_is_on(tr);
	r = sprintf(buf, "%d\n", r);

	return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
}

static ssize_t
rb_simple_write(struct file *filp, const char __user *ubuf,
		size_t cnt, loff_t *ppos)
{
	struct trace_array *tr = filp->private_data;
	struct ring_buffer *buffer = tr->trace_buffer.buffer;
	unsigned long val;
	int ret;

	ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
	if (ret)
		return ret;

	if (buffer) {
		mutex_lock(&trace_types_lock);
		if (val) {
			tracer_tracing_on(tr);
			if (tr->current_trace->start)
				tr->current_trace->start(tr);
		} else {
			tracer_tracing_off(tr);
			if (tr->current_trace->stop)
				tr->current_trace->stop(tr);
		}
		mutex_unlock(&trace_types_lock);
	}

	(*ppos)++;

	return cnt;
}

static const struct file_operations rb_simple_fops = {
	.open		= tracing_open_generic_tr,
	.read		= rb_simple_read,
	.write		= rb_simple_write,
	.release	= tracing_release_generic_tr,
	.llseek		= default_llseek,
};

struct dentry *trace_instance_dir;

static void
init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer);

static void init_trace_buffers(struct trace_array *tr, struct trace_buffer *buf)
{
	int cpu;

	for_each_tracing_cpu(cpu) {
		memset(per_cpu_ptr(buf->data, cpu), 0, sizeof(struct trace_array_cpu));
		per_cpu_ptr(buf->data, cpu)->trace_cpu.cpu = cpu;
		per_cpu_ptr(buf->data, cpu)->trace_cpu.tr = tr;
	}
}

static int
allocate_trace_buffer(struct trace_array *tr, struct trace_buffer *buf, int size)
{
	enum ring_buffer_flags rb_flags;

	rb_flags = trace_flags & TRACE_ITER_OVERWRITE ? RB_FL_OVERWRITE : 0;

	buf->buffer = ring_buffer_alloc(size, rb_flags);
	if (!buf->buffer)
		return -ENOMEM;

	buf->data = alloc_percpu(struct trace_array_cpu);
	if (!buf->data) {
		ring_buffer_free(buf->buffer);
		return -ENOMEM;
	}

	init_trace_buffers(tr, buf);

	/* Allocate the first page for all buffers */
	set_buffer_entries(&tr->trace_buffer,
			   ring_buffer_size(tr->trace_buffer.buffer, 0));

	return 0;
}

static int allocate_trace_buffers(struct trace_array *tr, int size)
{
	int ret;

	ret = allocate_trace_buffer(tr, &tr->trace_buffer, size);
	if (ret)
		return ret;

#ifdef CONFIG_TRACER_MAX_TRACE
	ret = allocate_trace_buffer(tr, &tr->max_buffer,
				    allocate_snapshot ? size : 1);
	if (WARN_ON(ret)) {
		ring_buffer_free(tr->trace_buffer.buffer);
		free_percpu(tr->trace_buffer.data);
		return -ENOMEM;
	}
	tr->allocated_snapshot = allocate_snapshot;

	/*
	 * Only the top level trace array gets its snapshot allocated
	 * from the kernel command line.
	 */
	allocate_snapshot = false;
#endif
	return 0;
}

static int new_instance_create(const char *name)
{
	struct trace_array *tr;
	int ret;

	mutex_lock(&trace_types_lock);

	ret = -EEXIST;
	list_for_each_entry(tr, &ftrace_trace_arrays, list) {
		if (tr->name && strcmp(tr->name, name) == 0)
			goto out_unlock;
	}

	ret = -ENOMEM;
	tr = kzalloc(sizeof(*tr), GFP_KERNEL);
	if (!tr)
		goto out_unlock;

	tr->name = kstrdup(name, GFP_KERNEL);
	if (!tr->name)
		goto out_free_tr;

	raw_spin_lock_init(&tr->start_lock);

	tr->current_trace = &nop_trace;

	INIT_LIST_HEAD(&tr->systems);
	INIT_LIST_HEAD(&tr->events);

	if (allocate_trace_buffers(tr, trace_buf_size) < 0)
		goto out_free_tr;

	/* Holder for file callbacks */
	tr->trace_cpu.cpu = RING_BUFFER_ALL_CPUS;
	tr->trace_cpu.tr = tr;

	tr->dir = debugfs_create_dir(name, trace_instance_dir);
	if (!tr->dir)
		goto out_free_tr;

	ret = event_trace_add_tracer(tr->dir, tr);
	if (ret) {
		debugfs_remove_recursive(tr->dir);
		goto out_free_tr;
	}

	init_tracer_debugfs(tr, tr->dir);

	list_add(&tr->list, &ftrace_trace_arrays);

	mutex_unlock(&trace_types_lock);

	return 0;

 out_free_tr:
	if (tr->trace_buffer.buffer)
		ring_buffer_free(tr->trace_buffer.buffer);
	kfree(tr->name);
	kfree(tr);

 out_unlock:
	mutex_unlock(&trace_types_lock);

	return ret;

}

static int instance_delete(const char *name)
{
	struct trace_array *tr;
	int found = 0;
	int ret;

	mutex_lock(&trace_types_lock);

	ret = -ENODEV;
	list_for_each_entry(tr, &ftrace_trace_arrays, list) {
		if (tr->name && strcmp(tr->name, name) == 0) {
			found = 1;
			break;
		}
	}
	if (!found)
		goto out_unlock;

	ret = -EBUSY;
	if (tr->ref)
		goto out_unlock;

	list_del(&tr->list);

	event_trace_del_tracer(tr);
	debugfs_remove_recursive(tr->dir);
	free_percpu(tr->trace_buffer.data);
	ring_buffer_free(tr->trace_buffer.buffer);

	kfree(tr->name);
	kfree(tr);

	ret = 0;

 out_unlock:
	mutex_unlock(&trace_types_lock);

	return ret;
}

static int instance_mkdir (struct inode *inode, struct dentry *dentry, umode_t mode)
{
	struct dentry *parent;
	int ret;

	/* Paranoid: Make sure the parent is the "instances" directory */
	parent = hlist_entry(inode->i_dentry.first, struct dentry, d_alias);
	if (WARN_ON_ONCE(parent != trace_instance_dir))
		return -ENOENT;

	/*
	 * The inode mutex is locked, but debugfs_create_dir() will also
	 * take the mutex. As the instances directory can not be destroyed
	 * or changed in any other way, it is safe to unlock it, and
	 * let the dentry try. If two users try to make the same dir at
	 * the same time, then the new_instance_create() will determine the
	 * winner.
	 */
	mutex_unlock(&inode->i_mutex);

	ret = new_instance_create(dentry->d_iname);

	mutex_lock(&inode->i_mutex);

	return ret;
}

static int instance_rmdir(struct inode *inode, struct dentry *dentry)
{
	struct dentry *parent;
	int ret;

	/* Paranoid: Make sure the parent is the "instances" directory */
	parent = hlist_entry(inode->i_dentry.first, struct dentry, d_alias);
	if (WARN_ON_ONCE(parent != trace_instance_dir))
		return -ENOENT;

	/* The caller did a dget() on dentry */
	mutex_unlock(&dentry->d_inode->i_mutex);

	/*
	 * The inode mutex is locked, but debugfs_create_dir() will also
	 * take the mutex. As the instances directory can not be destroyed
	 * or changed in any other way, it is safe to unlock it, and
	 * let the dentry try. If two users try to make the same dir at
	 * the same time, then the instance_delete() will determine the
	 * winner.
	 */
	mutex_unlock(&inode->i_mutex);

	ret = instance_delete(dentry->d_iname);

	mutex_lock_nested(&inode->i_mutex, I_MUTEX_PARENT);
	mutex_lock(&dentry->d_inode->i_mutex);

	return ret;
}

static const struct inode_operations instance_dir_inode_operations = {
	.lookup		= simple_lookup,
	.mkdir		= instance_mkdir,
	.rmdir		= instance_rmdir,
};

static __init void create_trace_instances(struct dentry *d_tracer)
{
	trace_instance_dir = debugfs_create_dir("instances", d_tracer);
	if (WARN_ON(!trace_instance_dir))
		return;

	/* Hijack the dir inode operations, to allow mkdir */
	trace_instance_dir->d_inode->i_op = &instance_dir_inode_operations;
}

static void
init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer)
{
	int cpu;

	trace_create_file("trace_options", 0644, d_tracer,
			  tr, &tracing_iter_fops);

	trace_create_file("trace", 0644, d_tracer,
			  tr, &tracing_fops);

	trace_create_file("trace_pipe", 0444, d_tracer,
			  tr, &tracing_pipe_fops);

	trace_create_file("buffer_size_kb", 0644, d_tracer,
			  tr, &tracing_entries_fops);

	trace_create_file("buffer_total_size_kb", 0444, d_tracer,
			  tr, &tracing_total_entries_fops);

	trace_create_file("free_buffer", 0644, d_tracer,
			  tr, &tracing_free_buffer_fops);

	trace_create_file("trace_marker", 0220, d_tracer,
			  tr, &tracing_mark_fops);

	trace_create_file("trace_clock", 0644, d_tracer, tr,
			  &trace_clock_fops);

	trace_create_file("tracing_on", 0644, d_tracer,
			  tr, &rb_simple_fops);

#ifdef CONFIG_TRACER_SNAPSHOT
	trace_create_file("snapshot", 0644, d_tracer,
			  tr, &snapshot_fops);
#endif

	for_each_tracing_cpu(cpu)
		tracing_init_debugfs_percpu(tr, cpu);

}

static __init int tracer_init_debugfs(void)
{
	struct dentry *d_tracer;

	trace_access_lock_init();

	d_tracer = tracing_init_dentry();
	if (!d_tracer)
		return 0;

	init_tracer_debugfs(&global_trace, d_tracer);

	trace_create_file("tracing_cpumask", 0644, d_tracer,
			&global_trace, &tracing_cpumask_fops);

	trace_create_file("available_tracers", 0444, d_tracer,
			&global_trace, &show_traces_fops);

	trace_create_file("current_tracer", 0644, d_tracer,
			&global_trace, &set_tracer_fops);

#ifdef CONFIG_TRACER_MAX_TRACE
	trace_create_file("tracing_max_latency", 0644, d_tracer,
			&tracing_max_latency, &tracing_max_lat_fops);
#endif

	trace_create_file("tracing_thresh", 0644, d_tracer,
			&tracing_thresh, &tracing_max_lat_fops);

	trace_create_file("README", 0444, d_tracer,
			NULL, &tracing_readme_fops);

	trace_create_file("saved_cmdlines", 0444, d_tracer,
			NULL, &tracing_saved_cmdlines_fops);

#ifdef CONFIG_DYNAMIC_FTRACE
	trace_create_file("dyn_ftrace_total_info", 0444, d_tracer,
			&ftrace_update_tot_cnt, &tracing_dyn_info_fops);
#endif

	create_trace_instances(d_tracer);

	create_trace_options_dir(&global_trace);

	return 0;
}

static int trace_panic_handler(struct notifier_block *this,
			       unsigned long event, void *unused)
{
	if (ftrace_dump_on_oops)
		ftrace_dump(ftrace_dump_on_oops);
	return NOTIFY_OK;
}

static struct notifier_block trace_panic_notifier = {
	.notifier_call  = trace_panic_handler,
	.next           = NULL,
	.priority       = 150   /* priority: INT_MAX >= x >= 0 */
};

static int trace_die_handler(struct notifier_block *self,
			     unsigned long val,
			     void *data)
{
	switch (val) {
	case DIE_OOPS:
		if (ftrace_dump_on_oops)
			ftrace_dump(ftrace_dump_on_oops);
		break;
	default:
		break;
	}
	return NOTIFY_OK;
}

static struct notifier_block trace_die_notifier = {
	.notifier_call = trace_die_handler,
	.priority = 200
};

/*
 * printk is set to max of 1024, we really don't need it that big.
 * Nothing should be printing 1000 characters anyway.
 */
#define TRACE_MAX_PRINT		1000

/*
 * Define here KERN_TRACE so that we have one place to modify
 * it if we decide to change what log level the ftrace dump
 * should be at.
 */
#define KERN_TRACE		KERN_EMERG

void
trace_printk_seq(struct trace_seq *s)
{
	/* Probably should print a warning here. */
	if (s->len >= TRACE_MAX_PRINT)
		s->len = TRACE_MAX_PRINT;

	/* should be zero ended, but we are paranoid. */
	s->buffer[s->len] = 0;

	printk(KERN_TRACE "%s", s->buffer);

	trace_seq_init(s);
}

void trace_init_global_iter(struct trace_iterator *iter)
{
	iter->tr = &global_trace;
	iter->trace = iter->tr->current_trace;
	iter->cpu_file = RING_BUFFER_ALL_CPUS;
	iter->trace_buffer = &global_trace.trace_buffer;
}

void ftrace_dump(enum ftrace_dump_mode oops_dump_mode)
{
	/* use static because iter can be a bit big for the stack */
	static struct trace_iterator iter;
	static atomic_t dump_running;
	unsigned int old_userobj;
	unsigned long flags;
	int cnt = 0, cpu;

	/* Only allow one dump user at a time. */
	if (atomic_inc_return(&dump_running) != 1) {
		atomic_dec(&dump_running);
		return;
	}

	/*
	 * Always turn off tracing when we dump.
	 * We don't need to show trace output of what happens
	 * between multiple crashes.
	 *
	 * If the user does a sysrq-z, then they can re-enable
	 * tracing with echo 1 > tracing_on.
	 */
	tracing_off();

	local_irq_save(flags);

	/* Simulate the iterator */
	trace_init_global_iter(&iter);

	for_each_tracing_cpu(cpu) {
		atomic_inc(&per_cpu_ptr(iter.tr->trace_buffer.data, cpu)->disabled);
	}

	old_userobj = trace_flags & TRACE_ITER_SYM_USEROBJ;

	/* don't look at user memory in panic mode */
	trace_flags &= ~TRACE_ITER_SYM_USEROBJ;

	switch (oops_dump_mode) {
	case DUMP_ALL:
		iter.cpu_file = RING_BUFFER_ALL_CPUS;
		break;
	case DUMP_ORIG:
		iter.cpu_file = raw_smp_processor_id();
		break;
	case DUMP_NONE:
		goto out_enable;
	default:
		printk(KERN_TRACE "Bad dumping mode, switching to all CPUs dump\n");
		iter.cpu_file = RING_BUFFER_ALL_CPUS;
	}

	printk(KERN_TRACE "Dumping ftrace buffer:\n");

	/* Did function tracer already get disabled? */
	if (ftrace_is_dead()) {
		printk("# WARNING: FUNCTION TRACING IS CORRUPTED\n");
		printk("#          MAY BE MISSING FUNCTION EVENTS\n");
	}

	/*
	 * We need to stop all tracing on all CPUS to read the
	 * the next buffer. This is a bit expensive, but is
	 * not done often. We fill all what we can read,
	 * and then release the locks again.
	 */

	while (!trace_empty(&iter)) {

		if (!cnt)
			printk(KERN_TRACE "---------------------------------\n");

		cnt++;

		/* reset all but tr, trace, and overruns */
		memset(&iter.seq, 0,
		       sizeof(struct trace_iterator) -
		       offsetof(struct trace_iterator, seq));
		iter.iter_flags |= TRACE_FILE_LAT_FMT;
		iter.pos = -1;

		if (trace_find_next_entry_inc(&iter) != NULL) {
			int ret;

			ret = print_trace_line(&iter);
			if (ret != TRACE_TYPE_NO_CONSUME)
				trace_consume(&iter);
		}
		touch_nmi_watchdog();

		trace_printk_seq(&iter.seq);
	}

	if (!cnt)
		printk(KERN_TRACE "   (ftrace buffer empty)\n");
	else
		printk(KERN_TRACE "---------------------------------\n");

 out_enable:
	trace_flags |= old_userobj;

	for_each_tracing_cpu(cpu) {
		atomic_dec(&per_cpu_ptr(iter.trace_buffer->data, cpu)->disabled);
	}
 	atomic_dec(&dump_running);
	local_irq_restore(flags);
}
EXPORT_SYMBOL_GPL(ftrace_dump);

__init static int tracer_alloc_buffers(void)
{
	int ring_buf_size;
	int ret = -ENOMEM;


	if (!alloc_cpumask_var(&tracing_buffer_mask, GFP_KERNEL))
		goto out;

	if (!alloc_cpumask_var(&tracing_cpumask, GFP_KERNEL))
		goto out_free_buffer_mask;

	/* Only allocate trace_printk buffers if a trace_printk exists */
	if (__stop___trace_bprintk_fmt != __start___trace_bprintk_fmt)
		/* Must be called before global_trace.buffer is allocated */
		trace_printk_init_buffers();

	/* To save memory, keep the ring buffer size to its minimum */
	if (ring_buffer_expanded)
		ring_buf_size = trace_buf_size;
	else
		ring_buf_size = 1;

	cpumask_copy(tracing_buffer_mask, cpu_possible_mask);
	cpumask_copy(tracing_cpumask, cpu_all_mask);

	raw_spin_lock_init(&global_trace.start_lock);

	/* TODO: make the number of buffers hot pluggable with CPUS */
	if (allocate_trace_buffers(&global_trace, ring_buf_size) < 0) {
		printk(KERN_ERR "tracer: failed to allocate ring buffer!\n");
		WARN_ON(1);
		goto out_free_cpumask;
	}

	if (global_trace.buffer_disabled)
		tracing_off();

	trace_init_cmdlines();

	/*
	 * register_tracer() might reference current_trace, so it
	 * needs to be set before we register anything. This is
	 * just a bootstrap of current_trace anyway.
	 */
	global_trace.current_trace = &nop_trace;

	register_tracer(&nop_trace);

	/* All seems OK, enable tracing */
	tracing_disabled = 0;

	atomic_notifier_chain_register(&panic_notifier_list,
				       &trace_panic_notifier);

	register_die_notifier(&trace_die_notifier);

	global_trace.flags = TRACE_ARRAY_FL_GLOBAL;

	/* Holder for file callbacks */
	global_trace.trace_cpu.cpu = RING_BUFFER_ALL_CPUS;
	global_trace.trace_cpu.tr = &global_trace;

	INIT_LIST_HEAD(&global_trace.systems);
	INIT_LIST_HEAD(&global_trace.events);
	list_add(&global_trace.list, &ftrace_trace_arrays);

	while (trace_boot_options) {
		char *option;

		option = strsep(&trace_boot_options, ",");
		trace_set_options(&global_trace, option);
	}

	register_snapshot_cmd();

	return 0;

out_free_cpumask:
	free_percpu(global_trace.trace_buffer.data);
#ifdef CONFIG_TRACER_MAX_TRACE
	free_percpu(global_trace.max_buffer.data);
#endif
	free_cpumask_var(tracing_cpumask);
out_free_buffer_mask:
	free_cpumask_var(tracing_buffer_mask);
out:
	return ret;
}

__init static int clear_boot_tracer(void)
{
	/*
	 * The default tracer at boot buffer is an init section.
	 * This function is called in lateinit. If we did not
	 * find the boot tracer, then clear it out, to prevent
	 * later registration from accessing the buffer that is
	 * about to be freed.
	 */
	if (!default_bootup_tracer)
		return 0;

	printk(KERN_INFO "ftrace bootup tracer '%s' not registered.\n",
	       default_bootup_tracer);
	default_bootup_tracer = NULL;

	return 0;
}

early_initcall(tracer_alloc_buffers);
fs_initcall(tracer_init_debugfs);
late_initcall(clear_boot_tracer);