module: refactor load_module part 5

1) Extract out the relocation loop into apply_relocations 2) Extract license and version checks into check_module_license_and_versions 3) Extract icache flushing into flush_module_icache 4) Move __obsparm warning into find_module_sections 5) Move license setting into check_modinfo. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

module: refactor load_module part 5
1) Extract out the relocation loop into apply_relocations 2) Extract license and version checks into check_module_license_and_versions 3) Extract icache flushing into flush_module_icache 4) Move __obsparm warning into find_module_sections 5) Move license setting into check_modinfo. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Rusty Russell
1 parent 9f85a4bbb1
Showing 1 changed file with 106 additions and 76 deletions Side-by-side Diff
kernel/module.c
@@ -1698,6 +1698,39 @@
 	return ret;
 }
  
+static int apply_relocations(struct module *mod,
+			     Elf_Ehdr *hdr,
+			     Elf_Shdr *sechdrs,
+			     unsigned int symindex,
+			     unsigned int strindex)
+{
+	unsigned int i;
+	int err = 0;
+
+	/* Now do relocations. */
+	for (i = 1; i < hdr->e_shnum; i++) {
+		const char *strtab = (char *)sechdrs[strindex].sh_addr;
+		unsigned int info = sechdrs[i].sh_info;
+
+		/* Not a valid relocation section? */
+		if (info >= hdr->e_shnum)
+			continue;
+
+		/* Don't bother with non-allocated sections */
+		if (!(sechdrs[info].sh_flags & SHF_ALLOC))
+			continue;
+
+		if (sechdrs[i].sh_type == SHT_REL)
+			err = apply_relocate(sechdrs, strtab, symindex, i, mod);
+		else if (sechdrs[i].sh_type == SHT_RELA)
+			err = apply_relocate_add(sechdrs, strtab, symindex, i,
+						 mod);
+		if (err < 0)
+			break;
+	}
+	return err;
+}
+
 /* Additional bytes needed by arch in front of individual sections */
 unsigned int __weak arch_mod_section_prepend(struct module *mod,
 					     unsigned int section)
@@ -2179,6 +2212,10 @@
 		       " the quality is unknown, you have been warned.\n",
 		       mod->name);
 	}
+
+	/* Set up license info based on the info section */
+	set_license(mod, get_modinfo(sechdrs, infoindex, "license"));
+
 	return 0;
 }
  
@@ -2245,6 +2282,10 @@
 					     sizeof(*mod->ftrace_callsites),
 					     &mod->num_ftrace_callsites);
 #endif
+
+	if (section_addr(hdr, sechdrs, secstrings, "__obsparm"))
+		printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
+		       mod->name);
 }
  
 static struct module *move_module(struct module *mod,
@@ -2311,6 +2352,60 @@
 	return mod;
 }
  
+static int check_module_license_and_versions(struct module *mod,
+					     Elf_Shdr *sechdrs)
+{
+	/*
+	 * ndiswrapper is under GPL by itself, but loads proprietary modules.
+	 * Don't use add_taint_module(), as it would prevent ndiswrapper from
+	 * using GPL-only symbols it needs.
+	 */
+	if (strcmp(mod->name, "ndiswrapper") == 0)
+		add_taint(TAINT_PROPRIETARY_MODULE);
+
+	/* driverloader was caught wrongly pretending to be under GPL */
+	if (strcmp(mod->name, "driverloader") == 0)
+		add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
+
+#ifdef CONFIG_MODVERSIONS
+	if ((mod->num_syms && !mod->crcs)
+	    || (mod->num_gpl_syms && !mod->gpl_crcs)
+	    || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
+#ifdef CONFIG_UNUSED_SYMBOLS
+	    || (mod->num_unused_syms && !mod->unused_crcs)
+	    || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
+#endif
+		) {
+		return try_to_force_load(mod,
+					 "no versions for exported symbols");
+	}
+#endif
+	return 0;
+}
+
+static void flush_module_icache(const struct module *mod)
+{
+	mm_segment_t old_fs;
+
+	/* flush the icache in correct context */
+	old_fs = get_fs();
+	set_fs(KERNEL_DS);
+
+	/*
+	 * Flush the instruction cache, since we've played with text.
+	 * Do it before processing of module parameters, so the module
+	 * can provide parameter accessor functions of its own.
+	 */
+	if (mod->module_init)
+		flush_icache_range((unsigned long)mod->module_init,
+				   (unsigned long)mod->module_init
+				   + mod->init_size);
+	flush_icache_range((unsigned long)mod->module_core,
+			   (unsigned long)mod->module_core + mod->core_size);
+
+	set_fs(old_fs);
+}
+
 /* Allocate and load the module: note that size of section 0 is always
    zero, and we rely on this for optional sections. */
 static noinline struct module *load_module(void __user *umod,
@@ -2331,8 +2426,6 @@
 	struct _ddebug *debug = NULL;
 	unsigned int num_debug = 0;
  
-	mm_segment_t old_fs;
-
 	DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n",
 	       umod, len, uargs);
  
  
  
@@ -2453,21 +2546,14 @@
 	if (err)
 		goto free_init;
  
-	/* Set up license info based on the info section */
-	set_license(mod, get_modinfo(sechdrs, infoindex, "license"));
+	/* Now we've got everything in the final locations, we can
+	 * find optional sections. */
+	find_module_sections(mod, hdr, sechdrs, secstrings);
  
-	/*
-	 * ndiswrapper is under GPL by itself, but loads proprietary modules.
-	 * Don't use add_taint_module(), as it would prevent ndiswrapper from
-	 * using GPL-only symbols it needs.
-	 */
-	if (strcmp(mod->name, "ndiswrapper") == 0)
-		add_taint(TAINT_PROPRIETARY_MODULE);
+	err = check_module_license_and_versions(mod, sechdrs);
+	if (err)
+		goto free_unload;
  
-	/* driverloader was caught wrongly pretending to be under GPL */
-	if (strcmp(mod->name, "driverloader") == 0)
-		add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
-
 	/* Set up MODINFO_ATTR fields */
 	setup_modinfo(mod, sechdrs, infoindex);
  
  
@@ -2477,48 +2563,10 @@
 	if (err < 0)
 		goto cleanup;
  
-	/* Now we've got everything in the final locations, we can
-	 * find optional sections. */
-	find_module_sections(mod, hdr, sechdrs, secstrings);
+	err = apply_relocations(mod, hdr, sechdrs, symindex, strindex);
+	if (err < 0)
+		goto cleanup;
  
-#ifdef CONFIG_MODVERSIONS
-	if ((mod->num_syms && !mod->crcs)
-	    || (mod->num_gpl_syms && !mod->gpl_crcs)
-	    || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
-#ifdef CONFIG_UNUSED_SYMBOLS
-	    || (mod->num_unused_syms && !mod->unused_crcs)
-	    || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
-#endif
-		) {
-		err = try_to_force_load(mod,
-					"no versions for exported symbols");
-		if (err)
-			goto cleanup;
-	}
-#endif
-
-	/* Now do relocations. */
-	for (i = 1; i < hdr->e_shnum; i++) {
-		const char *strtab = (char *)sechdrs[strindex].sh_addr;
-		unsigned int info = sechdrs[i].sh_info;
-
-		/* Not a valid relocation section? */
-		if (info >= hdr->e_shnum)
-			continue;
-
-		/* Don't bother with non-allocated sections */
-		if (!(sechdrs[info].sh_flags & SHF_ALLOC))
-			continue;
-
-		if (sechdrs[i].sh_type == SHT_REL)
-			err = apply_relocate(sechdrs, strtab, symindex, i,mod);
-		else if (sechdrs[i].sh_type == SHT_RELA)
-			err = apply_relocate_add(sechdrs, strtab, symindex, i,
-						 mod);
-		if (err < 0)
-			goto cleanup;
-	}
-
   	/* Set up and sort exception table */
 	mod->extable = section_objs(hdr, sechdrs, secstrings, "__ex_table",
 				    sizeof(*mod->extable), &mod->num_exentries);
  
  
@@ -2541,28 +2589,9 @@
 	if (err < 0)
 		goto cleanup;
  
-	/* flush the icache in correct context */
-	old_fs = get_fs();
-	set_fs(KERNEL_DS);
+	flush_module_icache(mod);
  
-	/*
-	 * Flush the instruction cache, since we've played with text.
-	 * Do it before processing of module parameters, so the module
-	 * can provide parameter accessor functions of its own.
-	 */
-	if (mod->module_init)
-		flush_icache_range((unsigned long)mod->module_init,
-				   (unsigned long)mod->module_init
-				   + mod->init_size);
-	flush_icache_range((unsigned long)mod->module_core,
-			   (unsigned long)mod->module_core + mod->core_size);
-
-	set_fs(old_fs);
-
 	mod->args = args;
-	if (section_addr(hdr, sechdrs, secstrings, "__obsparm"))
-		printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
-		       mod->name);
  
 	/* Now sew it into the lists so we can get lockdep and oops
 	 * info during argument parsing.  Noone should access us, since
@@ -2619,6 +2648,7 @@
 	module_arch_cleanup(mod);
  cleanup:
 	free_modinfo(mod);
+ free_unload:
 	module_unload_free(mod);
  free_init:
 	module_free(mod, mod->module_init);
...	...	@@ -1698,6 +1698,39 @@
1698	1698	return ret;
1699	1699	}
1700	1700
	1701	+static int apply_relocations(struct module *mod,
	1702	+ Elf_Ehdr *hdr,
	1703	+ Elf_Shdr *sechdrs,
	1704	+ unsigned int symindex,
	1705	+ unsigned int strindex)
	1706	+{
	1707	+ unsigned int i;
	1708	+ int err = 0;
	1709	+
	1710	+ /* Now do relocations. */
	1711	+ for (i = 1; i < hdr->e_shnum; i++) {
	1712	+ const char strtab = (char )sechdrs[strindex].sh_addr;
	1713	+ unsigned int info = sechdrs[i].sh_info;
	1714	+
	1715	+ /* Not a valid relocation section? */
	1716	+ if (info >= hdr->e_shnum)
	1717	+ continue;
	1718	+
	1719	+ /* Don't bother with non-allocated sections */
	1720	+ if (!(sechdrs[info].sh_flags & SHF_ALLOC))
	1721	+ continue;
	1722	+
	1723	+ if (sechdrs[i].sh_type == SHT_REL)
	1724	+ err = apply_relocate(sechdrs, strtab, symindex, i, mod);
	1725	+ else if (sechdrs[i].sh_type == SHT_RELA)
	1726	+ err = apply_relocate_add(sechdrs, strtab, symindex, i,
	1727	+ mod);
	1728	+ if (err < 0)
	1729	+ break;
	1730	+ }
	1731	+ return err;
	1732	+}
	1733	+
1701	1734	/* Additional bytes needed by arch in front of individual sections */
1702	1735	unsigned int __weak arch_mod_section_prepend(struct module *mod,
1703	1736	unsigned int section)
...	...	@@ -2179,6 +2212,10 @@
2179	2212	" the quality is unknown, you have been warned.\n",
2180	2213	mod->name);
2181	2214	}
	2215	+
	2216	+ /* Set up license info based on the info section */
	2217	+ set_license(mod, get_modinfo(sechdrs, infoindex, "license"));
	2218	+
2182	2219	return 0;
2183	2220	}
2184	2221
...	...	@@ -2245,6 +2282,10 @@
2245	2282	sizeof(*mod->ftrace_callsites),
2246	2283	&mod->num_ftrace_callsites);
2247	2284	#endif
	2285	+
	2286	+ if (section_addr(hdr, sechdrs, secstrings, "__obsparm"))
	2287	+ printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
	2288	+ mod->name);
2248	2289	}
2249	2290
2250	2291	static struct module move_module(struct module mod,
...	...	@@ -2311,6 +2352,60 @@
2311	2352	return mod;
2312	2353	}
2313	2354
	2355	+static int check_module_license_and_versions(struct module *mod,
	2356	+ Elf_Shdr *sechdrs)
	2357	+{
	2358	+ /*
	2359	+ * ndiswrapper is under GPL by itself, but loads proprietary modules.
	2360	+ * Don't use add_taint_module(), as it would prevent ndiswrapper from
	2361	+ * using GPL-only symbols it needs.
	2362	+ */
	2363	+ if (strcmp(mod->name, "ndiswrapper") == 0)
	2364	+ add_taint(TAINT_PROPRIETARY_MODULE);
	2365	+
	2366	+ /* driverloader was caught wrongly pretending to be under GPL */
	2367	+ if (strcmp(mod->name, "driverloader") == 0)
	2368	+ add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
	2369	+
	2370	+#ifdef CONFIG_MODVERSIONS
	2371	+ if ((mod->num_syms && !mod->crcs)
	2372	+ \|\| (mod->num_gpl_syms && !mod->gpl_crcs)
	2373	+ \|\| (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
	2374	+#ifdef CONFIG_UNUSED_SYMBOLS
	2375	+ \|\| (mod->num_unused_syms && !mod->unused_crcs)
	2376	+ \|\| (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
	2377	+#endif
	2378	+ ) {
	2379	+ return try_to_force_load(mod,
	2380	+ "no versions for exported symbols");
	2381	+ }
	2382	+#endif
	2383	+ return 0;
	2384	+}
	2385	+
	2386	+static void flush_module_icache(const struct module *mod)
	2387	+{
	2388	+ mm_segment_t old_fs;
	2389	+
	2390	+ /* flush the icache in correct context */
	2391	+ old_fs = get_fs();
	2392	+ set_fs(KERNEL_DS);
	2393	+
	2394	+ /*
	2395	+ * Flush the instruction cache, since we've played with text.
	2396	+ * Do it before processing of module parameters, so the module
	2397	+ * can provide parameter accessor functions of its own.
	2398	+ */
	2399	+ if (mod->module_init)
	2400	+ flush_icache_range((unsigned long)mod->module_init,
	2401	+ (unsigned long)mod->module_init
	2402	+ + mod->init_size);
	2403	+ flush_icache_range((unsigned long)mod->module_core,
	2404	+ (unsigned long)mod->module_core + mod->core_size);
	2405	+
	2406	+ set_fs(old_fs);
	2407	+}
	2408	+
2314	2409	/* Allocate and load the module: note that size of section 0 is always
2315	2410	zero, and we rely on this for optional sections. */
2316	2411	static noinline struct module load_module(void __user umod,
...	...	@@ -2331,8 +2426,6 @@
2331	2426	struct _ddebug *debug = NULL;
2332	2427	unsigned int num_debug = 0;
2333	2428
2334		- mm_segment_t old_fs;
2335		-
2336	2429	DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n",
2337	2430	umod, len, uargs);
2338	2431
2339	2432
2340	2433
...	...	@@ -2453,21 +2546,14 @@
2453	2546	if (err)
2454	2547	goto free_init;
2455	2548
2456		- /* Set up license info based on the info section */
2457		- set_license(mod, get_modinfo(sechdrs, infoindex, "license"));
	2549	+ /* Now we've got everything in the final locations, we can
	2550	+ * find optional sections. */
	2551	+ find_module_sections(mod, hdr, sechdrs, secstrings);
2458	2552
2459		- /*
2460		- * ndiswrapper is under GPL by itself, but loads proprietary modules.
2461		- * Don't use add_taint_module(), as it would prevent ndiswrapper from
2462		- * using GPL-only symbols it needs.
2463		- */
2464		- if (strcmp(mod->name, "ndiswrapper") == 0)
2465		- add_taint(TAINT_PROPRIETARY_MODULE);
	2553	+ err = check_module_license_and_versions(mod, sechdrs);
	2554	+ if (err)
	2555	+ goto free_unload;
2466	2556
2467		- /* driverloader was caught wrongly pretending to be under GPL */
2468		- if (strcmp(mod->name, "driverloader") == 0)
2469		- add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
2470		-
2471	2557	/* Set up MODINFO_ATTR fields */
2472	2558	setup_modinfo(mod, sechdrs, infoindex);
2473	2559
2474	2560
...	...	@@ -2477,48 +2563,10 @@
2477	2563	if (err < 0)
2478	2564	goto cleanup;
2479	2565
2480		- /* Now we've got everything in the final locations, we can
2481		- * find optional sections. */
2482		- find_module_sections(mod, hdr, sechdrs, secstrings);
	2566	+ err = apply_relocations(mod, hdr, sechdrs, symindex, strindex);
	2567	+ if (err < 0)
	2568	+ goto cleanup;
2483	2569
2484		-#ifdef CONFIG_MODVERSIONS
2485		- if ((mod->num_syms && !mod->crcs)
2486		- \|\| (mod->num_gpl_syms && !mod->gpl_crcs)
2487		- \|\| (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
2488		-#ifdef CONFIG_UNUSED_SYMBOLS
2489		- \|\| (mod->num_unused_syms && !mod->unused_crcs)
2490		- \|\| (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
2491		-#endif
2492		- ) {
2493		- err = try_to_force_load(mod,
2494		- "no versions for exported symbols");
2495		- if (err)
2496		- goto cleanup;
2497		- }
2498		-#endif
2499		-
2500		- /* Now do relocations. */
2501		- for (i = 1; i < hdr->e_shnum; i++) {
2502		- const char strtab = (char )sechdrs[strindex].sh_addr;
2503		- unsigned int info = sechdrs[i].sh_info;
2504		-
2505		- /* Not a valid relocation section? */
2506		- if (info >= hdr->e_shnum)
2507		- continue;
2508		-
2509		- /* Don't bother with non-allocated sections */
2510		- if (!(sechdrs[info].sh_flags & SHF_ALLOC))
2511		- continue;
2512		-
2513		- if (sechdrs[i].sh_type == SHT_REL)
2514		- err = apply_relocate(sechdrs, strtab, symindex, i,mod);
2515		- else if (sechdrs[i].sh_type == SHT_RELA)
2516		- err = apply_relocate_add(sechdrs, strtab, symindex, i,
2517		- mod);
2518		- if (err < 0)
2519		- goto cleanup;
2520		- }
2521		-
2522	2570	/* Set up and sort exception table */
2523	2571	mod->extable = section_objs(hdr, sechdrs, secstrings, "__ex_table",
2524	2572	sizeof(*mod->extable), &mod->num_exentries);
2525	2573
2526	2574
...	...	@@ -2541,28 +2589,9 @@
2541	2589	if (err < 0)
2542	2590	goto cleanup;
2543	2591
2544		- /* flush the icache in correct context */
2545		- old_fs = get_fs();
2546		- set_fs(KERNEL_DS);
	2592	+ flush_module_icache(mod);
2547	2593
2548		- /*
2549		- * Flush the instruction cache, since we've played with text.
2550		- * Do it before processing of module parameters, so the module
2551		- * can provide parameter accessor functions of its own.
2552		- */
2553		- if (mod->module_init)
2554		- flush_icache_range((unsigned long)mod->module_init,
2555		- (unsigned long)mod->module_init
2556		- + mod->init_size);
2557		- flush_icache_range((unsigned long)mod->module_core,
2558		- (unsigned long)mod->module_core + mod->core_size);
2559		-
2560		- set_fs(old_fs);
2561		-
2562	2594	mod->args = args;
2563		- if (section_addr(hdr, sechdrs, secstrings, "__obsparm"))
2564		- printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
2565		- mod->name);
2566	2595
2567	2596	/* Now sew it into the lists so we can get lockdep and oops
2568	2597	* info during argument parsing. Noone should access us, since
...	...	@@ -2619,6 +2648,7 @@
2619	2648	module_arch_cleanup(mod);
2620	2649	cleanup:
2621	2650	free_modinfo(mod);
	2651	+ free_unload:
2622	2652	module_unload_free(mod);
2623	2653	free_init:
2624	2654	module_free(mod, mod->module_init);