panic: Allow warnings to set different taint flags

WARN() is used in some places to report firmware or hardware bugs that are then worked-around. These bugs do not affect the stability of the kernel and should not set the flag for TAINT_WARN. To allow for this, add WARN_TAINT() and WARN_TAINT_ONCE() macros that take a taint number as argument. Architectures that implement warnings using trap instructions instead of calls to warn_slowpath_*() now implement __WARN_TAINT(taint) instead of __WARN(). Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Acked-by: Helge Deller <deller@gmx.de> Tested-by: Paul Mundt <lethal@linux-sh.org> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

panic: Allow warnings to set different taint flags
WARN() is used in some places to report firmware or hardware bugs that are then worked-around. These bugs do not affect the stability of the kernel and should not set the flag for TAINT_WARN. To allow for this, add WARN_TAINT() and WARN_TAINT_ONCE() macros that take a taint number as argument. Architectures that implement warnings using trap instructions instead of calls to warn_slowpath_*() now implement __WARN_TAINT(taint) instead of __WARN(). Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Acked-by: Helge Deller <deller@gmx.de> Tested-by: Paul Mundt <lethal@linux-sh.org> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Ben Hutchings · David Woodhouse
1 parent 8954da1f82
Showing 8 changed files with 67 additions and 20 deletions Side-by-side Diff
Documentation/oops-tracing.txt
arch/parisc/include/asm/bug.h
arch/powerpc/include/asm/bug.h
arch/s390/include/asm/bug.h
arch/sh/include/asm/bug.h
include/asm-generic/bug.h
kernel/panic.c
lib/bug.c
@@ -256,6 +256,7 @@
   9: 'A' if the ACPI table has been overridden.
  
  10: 'W' if a warning has previously been issued by the kernel.
+     (Though some warnings may set more specific taint flags.)
  
  11: 'C' if a staging driver has been loaded.
  
@@ -44,7 +44,7 @@
 #endif
  
 #ifdef CONFIG_DEBUG_BUGVERBOSE
-#define __WARN()							\
+#define __WARN_TAINT(taint)						\
 	do {								\
 		asm volatile("\n"					\
 			     "1:\t" PARISC_BUG_BREAK_ASM "\n"		\
  
@@ -54,11 +54,11 @@
 			     "\t.org 2b+%c3\n"				\
 			     "\t.popsection"				\
 			     : : "i" (__FILE__), "i" (__LINE__),	\
-			     "i" (BUGFLAG_WARNING),			\
+			     "i" (BUGFLAG_TAINT(taint)), 		\
 			     "i" (sizeof(struct bug_entry)) );		\
 	} while(0)
 #else
-#define __WARN()							\
+#define __WARN_TAINT(taint)						\
 	do {								\
 		asm volatile("\n"					\
 			     "1:\t" PARISC_BUG_BREAK_ASM "\n"		\
@@ -67,7 +67,7 @@
 			     "\t.short %c0\n"				\
 			     "\t.org 2b+%c1\n"				\
 			     "\t.popsection"				\
-			     : : "i" (BUGFLAG_WARNING),			\
+			     : : "i" (BUGFLAG_TAINT(taint)),		\
 			     "i" (sizeof(struct bug_entry)) );		\
 	} while(0)
 #endif
@@ -85,12 +85,12 @@
 	}							\
 } while (0)
  
-#define __WARN() do {						\
+#define __WARN_TAINT(taint) do {				\
 	__asm__ __volatile__(					\
 		"1:	twi 31,0,0\n"				\
 		_EMIT_BUG_ENTRY					\
 		: : "i" (__FILE__), "i" (__LINE__),		\
-		  "i" (BUGFLAG_WARNING),			\
+		  "i" (BUGFLAG_TAINT(taint)),			\
 		  "i" (sizeof(struct bug_entry)));		\
 } while (0)
  
@@ -104,7 +104,7 @@
 		"1:	"PPC_TLNEI"	%4,0\n"			\
 		_EMIT_BUG_ENTRY					\
 		: : "i" (__FILE__), "i" (__LINE__),		\
-		  "i" (BUGFLAG_WARNING),			\
+		  "i" (BUGFLAG_TAINT(TAINT_WARN)),		\
 		  "i" (sizeof(struct bug_entry)),		\
 		  "r" (__ret_warn_on));				\
 	}							\
@@ -46,18 +46,18 @@
 	unreachable();					\
 } while (0)
  
-#define __WARN() do {					\
-	__EMIT_BUG(BUGFLAG_WARNING);			\
+#define __WARN_TAINT(taint) do {			\
+	__EMIT_BUG(BUGFLAG_TAINT(taint));		\
 } while (0)
  
 #define WARN_ON(x) ({					\
 	int __ret_warn_on = !!(x);			\
 	if (__builtin_constant_p(__ret_warn_on)) {	\
 		if (__ret_warn_on)			\
-			__EMIT_BUG(BUGFLAG_WARNING);	\
+			__WARN();			\
 	} else {					\
 		if (unlikely(__ret_warn_on))		\
-			__EMIT_BUG(BUGFLAG_WARNING);	\
+			__WARN();			\
 	}						\
 	unlikely(__ret_warn_on);			\
 })
@@ -48,7 +48,7 @@
 		   "i" (sizeof(struct bug_entry)));	\
 } while (0)
  
-#define __WARN()					\
+#define __WARN_TAINT(taint)				\
 do {							\
 	__asm__ __volatile__ (				\
 		"1:\t.short %O0\n"			\
@@ -57,7 +57,7 @@
 		 : "n" (TRAPA_BUG_OPCODE),		\
 		   "i" (__FILE__),			\
 		   "i" (__LINE__),			\
-		   "i" (BUGFLAG_WARNING),		\
+		   "i" (BUGFLAG_TAINT(taint)),		\
 		   "i" (sizeof(struct bug_entry)));	\
 } while (0)
  
@@ -25,7 +25,10 @@
 };
 #endif		/* __ASSEMBLY__ */
  
-#define BUGFLAG_WARNING	(1<<0)
+#define BUGFLAG_WARNING		(1 << 0)
+#define BUGFLAG_TAINT(taint)	(BUGFLAG_WARNING | ((taint) << 8))
+#define BUG_GET_TAINT(bug)	((bug)->flags >> 8)
+
 #endif	/* CONFIG_GENERIC_BUG */
  
 /*
  
  
  
  
@@ -56,17 +59,25 @@
  * appear at runtime.  Use the versions with printk format strings
  * to provide better diagnostics.
  */
-#ifndef __WARN
+#ifndef __WARN_TAINT
 #ifndef __ASSEMBLY__
 extern void warn_slowpath_fmt(const char *file, const int line,
 		const char *fmt, ...) __attribute__((format(printf, 3, 4)));
+extern void warn_slowpath_fmt_taint(const char *file, const int line,
+				    unsigned taint, const char *fmt, ...)
+	__attribute__((format(printf, 4, 5)));
 extern void warn_slowpath_null(const char *file, const int line);
 #define WANT_WARN_ON_SLOWPATH
 #endif
 #define __WARN()		warn_slowpath_null(__FILE__, __LINE__)
 #define __WARN_printf(arg...)	warn_slowpath_fmt(__FILE__, __LINE__, arg)
+#define __WARN_printf_taint(taint, arg...)				\
+	warn_slowpath_fmt_taint(__FILE__, __LINE__, taint, arg)
 #else
+#define __WARN()		__WARN_TAINT(TAINT_WARN)
 #define __WARN_printf(arg...)	do { printk(arg); __WARN(); } while (0)
+#define __WARN_printf_taint(taint, arg...)				\
+	do { printk(arg); __WARN_TAINT(taint); } while (0)
 #endif
  
 #ifndef WARN_ON
@@ -87,6 +98,13 @@
 })
 #endif
  
+#define WARN_TAINT(condition, taint, format...) ({			\
+	int __ret_warn_on = !!(condition);				\
+	if (unlikely(__ret_warn_on))					\
+		__WARN_printf_taint(taint, format);			\
+	unlikely(__ret_warn_on);					\
+})
+
 #else /* !CONFIG_BUG */
 #ifndef HAVE_ARCH_BUG
 #define BUG() do {} while(0)
@@ -110,6 +128,8 @@
 })
 #endif
  
+#define WARN_TAINT(condition, taint, format...) WARN_ON(condition)
+
 #endif
  
 #define WARN_ON_ONCE(condition)	({				\
@@ -128,6 +148,16 @@
 								\
 	if (unlikely(__ret_warn_once))				\
 		if (WARN(!__warned, format)) 			\
+			__warned = true;			\
+	unlikely(__ret_warn_once);				\
+})
+
+#define WARN_TAINT_ONCE(condition, taint, format...)	({	\
+	static bool __warned;					\
+	int __ret_warn_once = !!(condition);			\
+								\
+	if (unlikely(__ret_warn_once))				\
+		if (WARN_TAINT(!__warned, taint, format))	\
 			__warned = true;			\
 	unlikely(__ret_warn_once);				\
 })
@@ -365,7 +365,8 @@
 	va_list args;
 };
  
-static void warn_slowpath_common(const char *file, int line, void *caller, struct slowpath_args *args)
+static void warn_slowpath_common(const char *file, int line, void *caller,
+				 unsigned taint, struct slowpath_args *args)
 {
 	const char *board;
  
@@ -381,7 +382,7 @@
 	print_modules();
 	dump_stack();
 	print_oops_end_marker();
-	add_taint(TAINT_WARN);
+	add_taint(taint);
 }
  
 void warn_slowpath_fmt(const char *file, int line, const char *fmt, ...)
  
  
@@ -390,14 +391,29 @@
  
 	args.fmt = fmt;
 	va_start(args.args, fmt);
-	warn_slowpath_common(file, line, __builtin_return_address(0), &args);
+	warn_slowpath_common(file, line, __builtin_return_address(0),
+			     TAINT_WARN, &args);
 	va_end(args.args);
 }
 EXPORT_SYMBOL(warn_slowpath_fmt);
  
+void warn_slowpath_fmt_taint(const char *file, int line,
+			     unsigned taint, const char *fmt, ...)
+{
+	struct slowpath_args args;
+
+	args.fmt = fmt;
+	va_start(args.args, fmt);
+	warn_slowpath_common(file, line, __builtin_return_address(0),
+			     taint, &args);
+	va_end(args.args);
+}
+EXPORT_SYMBOL(warn_slowpath_fmt_taint);
+
 void warn_slowpath_null(const char *file, int line)
 {
-	warn_slowpath_common(file, line, __builtin_return_address(0), NULL);
+	warn_slowpath_common(file, line, __builtin_return_address(0),
+			     TAINT_WARN, NULL);
 }
 EXPORT_SYMBOL(warn_slowpath_null);
 #endif
@@ -165,7 +165,7 @@
 			       (void *)bugaddr);
  
 		show_regs(regs);
-		add_taint(TAINT_WARN);
+		add_taint(BUG_GET_TAINT(bug));
 		return BUG_TRAP_TYPE_WARN;
 	}
...	...	@@ -256,6 +256,7 @@
256	256	9: 'A' if the ACPI table has been overridden.
257	257
258	258	10: 'W' if a warning has previously been issued by the kernel.
	259	+ (Though some warnings may set more specific taint flags.)
259	260
260	261	11: 'C' if a staging driver has been loaded.
261	262
...	...	@@ -44,7 +44,7 @@
44	44	#endif
45	45
46	46	#ifdef CONFIG_DEBUG_BUGVERBOSE
47		-#define __WARN() \
	47	+#define __WARN_TAINT(taint) \
48	48	do { \
49	49	asm volatile("\n" \
50	50	"1:\t" PARISC_BUG_BREAK_ASM "\n" \
51	51
...	...	@@ -54,11 +54,11 @@
54	54	"\t.org 2b+%c3\n" \
55	55	"\t.popsection" \
56	56	: : "i" (__FILE__), "i" (__LINE__), \
57		- "i" (BUGFLAG_WARNING), \
	57	+ "i" (BUGFLAG_TAINT(taint)), \
58	58	"i" (sizeof(struct bug_entry)) ); \
59	59	} while(0)
60	60	#else
61		-#define __WARN() \
	61	+#define __WARN_TAINT(taint) \
62	62	do { \
63	63	asm volatile("\n" \
64	64	"1:\t" PARISC_BUG_BREAK_ASM "\n" \
...	...	@@ -67,7 +67,7 @@
67	67	"\t.short %c0\n" \
68	68	"\t.org 2b+%c1\n" \
69	69	"\t.popsection" \
70		- : : "i" (BUGFLAG_WARNING), \
	70	+ : : "i" (BUGFLAG_TAINT(taint)), \
71	71	"i" (sizeof(struct bug_entry)) ); \
72	72	} while(0)
73	73	#endif
...	...	@@ -85,12 +85,12 @@
85	85	} \
86	86	} while (0)
87	87
88		-#define __WARN() do { \
	88	+#define __WARN_TAINT(taint) do { \
89	89	__asm__ __volatile__( \
90	90	"1: twi 31,0,0\n" \
91	91	_EMIT_BUG_ENTRY \
92	92	: : "i" (__FILE__), "i" (__LINE__), \
93		- "i" (BUGFLAG_WARNING), \
	93	+ "i" (BUGFLAG_TAINT(taint)), \
94	94	"i" (sizeof(struct bug_entry))); \
95	95	} while (0)
96	96
...	...	@@ -104,7 +104,7 @@
104	104	"1: "PPC_TLNEI" %4,0\n" \
105	105	_EMIT_BUG_ENTRY \
106	106	: : "i" (__FILE__), "i" (__LINE__), \
107		- "i" (BUGFLAG_WARNING), \
	107	+ "i" (BUGFLAG_TAINT(TAINT_WARN)), \
108	108	"i" (sizeof(struct bug_entry)), \
109	109	"r" (__ret_warn_on)); \
110	110	} \
...	...	@@ -46,18 +46,18 @@
46	46	unreachable(); \
47	47	} while (0)
48	48
49		-#define __WARN() do { \
50		- __EMIT_BUG(BUGFLAG_WARNING); \
	49	+#define __WARN_TAINT(taint) do { \
	50	+ __EMIT_BUG(BUGFLAG_TAINT(taint)); \
51	51	} while (0)
52	52
53	53	#define WARN_ON(x) ({ \
54	54	int __ret_warn_on = !!(x); \
55	55	if (__builtin_constant_p(__ret_warn_on)) { \
56	56	if (__ret_warn_on) \
57		- __EMIT_BUG(BUGFLAG_WARNING); \
	57	+ __WARN(); \
58	58	} else { \
59	59	if (unlikely(__ret_warn_on)) \
60		- __EMIT_BUG(BUGFLAG_WARNING); \
	60	+ __WARN(); \
61	61	} \
62	62	unlikely(__ret_warn_on); \
63	63	})
...	...	@@ -48,7 +48,7 @@
48	48	"i" (sizeof(struct bug_entry))); \
49	49	} while (0)
50	50
51		-#define __WARN() \
	51	+#define __WARN_TAINT(taint) \
52	52	do { \
53	53	__asm__ __volatile__ ( \
54	54	"1:\t.short %O0\n" \
...	...	@@ -57,7 +57,7 @@
57	57	: "n" (TRAPA_BUG_OPCODE), \
58	58	"i" (__FILE__), \
59	59	"i" (__LINE__), \
60		- "i" (BUGFLAG_WARNING), \
	60	+ "i" (BUGFLAG_TAINT(taint)), \
61	61	"i" (sizeof(struct bug_entry))); \
62	62	} while (0)
63	63
...	...	@@ -25,7 +25,10 @@
25	25	};
26	26	#endif /* __ASSEMBLY__ */
27	27
28		-#define BUGFLAG_WARNING (1<<0)
	28	+#define BUGFLAG_WARNING (1 << 0)
	29	+#define BUGFLAG_TAINT(taint) (BUGFLAG_WARNING \| ((taint) << 8))
	30	+#define BUG_GET_TAINT(bug) ((bug)->flags >> 8)
	31	+
29	32	#endif /* CONFIG_GENERIC_BUG */
30	33
31	34	/*
32	35
33	36
34	37
35	38
...	...	@@ -56,17 +59,25 @@
56	59	* appear at runtime. Use the versions with printk format strings
57	60	* to provide better diagnostics.
58	61	*/
59		-#ifndef __WARN
	62	+#ifndef __WARN_TAINT
60	63	#ifndef __ASSEMBLY__
61	64	extern void warn_slowpath_fmt(const char *file, const int line,
62	65	const char *fmt, ...) __attribute__((format(printf, 3, 4)));
	66	+extern void warn_slowpath_fmt_taint(const char *file, const int line,
	67	+ unsigned taint, const char *fmt, ...)
	68	+ __attribute__((format(printf, 4, 5)));
63	69	extern void warn_slowpath_null(const char *file, const int line);
64	70	#define WANT_WARN_ON_SLOWPATH
65	71	#endif
66	72	#define __WARN() warn_slowpath_null(__FILE__, __LINE__)
67	73	#define __WARN_printf(arg...) warn_slowpath_fmt(__FILE__, __LINE__, arg)
	74	+#define __WARN_printf_taint(taint, arg...) \
	75	+ warn_slowpath_fmt_taint(__FILE__, __LINE__, taint, arg)
68	76	#else
	77	+#define __WARN() __WARN_TAINT(TAINT_WARN)
69	78	#define __WARN_printf(arg...) do { printk(arg); __WARN(); } while (0)
	79	+#define __WARN_printf_taint(taint, arg...) \
	80	+ do { printk(arg); __WARN_TAINT(taint); } while (0)
70	81	#endif
71	82
72	83	#ifndef WARN_ON
...	...	@@ -87,6 +98,13 @@
87	98	})
88	99	#endif
89	100
	101	+#define WARN_TAINT(condition, taint, format...) ({ \
	102	+ int __ret_warn_on = !!(condition); \
	103	+ if (unlikely(__ret_warn_on)) \
	104	+ __WARN_printf_taint(taint, format); \
	105	+ unlikely(__ret_warn_on); \
	106	+})
	107	+
90	108	#else /* !CONFIG_BUG */
91	109	#ifndef HAVE_ARCH_BUG
92	110	#define BUG() do {} while(0)
...	...	@@ -110,6 +128,8 @@
110	128	})
111	129	#endif
112	130
	131	+#define WARN_TAINT(condition, taint, format...) WARN_ON(condition)
	132	+
113	133	#endif
114	134
115	135	#define WARN_ON_ONCE(condition) ({ \
...	...	@@ -128,6 +148,16 @@
128	148	\
129	149	if (unlikely(__ret_warn_once)) \
130	150	if (WARN(!__warned, format)) \
	151	+ __warned = true; \
	152	+ unlikely(__ret_warn_once); \
	153	+})
	154	+
	155	+#define WARN_TAINT_ONCE(condition, taint, format...) ({ \
	156	+ static bool __warned; \
	157	+ int __ret_warn_once = !!(condition); \
	158	+ \
	159	+ if (unlikely(__ret_warn_once)) \
	160	+ if (WARN_TAINT(!__warned, taint, format)) \
131	161	__warned = true; \
132	162	unlikely(__ret_warn_once); \
133	163	})
...	...	@@ -365,7 +365,8 @@
365	365	va_list args;
366	366	};
367	367
368		-static void warn_slowpath_common(const char file, int line, void caller, struct slowpath_args *args)
	368	+static void warn_slowpath_common(const char file, int line, void caller,
	369	+ unsigned taint, struct slowpath_args *args)
369	370	{
370	371	const char *board;
371	372
...	...	@@ -381,7 +382,7 @@
381	382	print_modules();
382	383	dump_stack();
383	384	print_oops_end_marker();
384		- add_taint(TAINT_WARN);
	385	+ add_taint(taint);
385	386	}
386	387
387	388	void warn_slowpath_fmt(const char file, int line, const char fmt, ...)
388	389
389	390
...	...	@@ -390,14 +391,29 @@
390	391
391	392	args.fmt = fmt;
392	393	va_start(args.args, fmt);
393		- warn_slowpath_common(file, line, __builtin_return_address(0), &args);
	394	+ warn_slowpath_common(file, line, __builtin_return_address(0),
	395	+ TAINT_WARN, &args);
394	396	va_end(args.args);
395	397	}
396	398	EXPORT_SYMBOL(warn_slowpath_fmt);
397	399
	400	+void warn_slowpath_fmt_taint(const char *file, int line,
	401	+ unsigned taint, const char *fmt, ...)
	402	+{
	403	+ struct slowpath_args args;
	404	+
	405	+ args.fmt = fmt;
	406	+ va_start(args.args, fmt);
	407	+ warn_slowpath_common(file, line, __builtin_return_address(0),
	408	+ taint, &args);
	409	+ va_end(args.args);
	410	+}
	411	+EXPORT_SYMBOL(warn_slowpath_fmt_taint);
	412	+
398	413	void warn_slowpath_null(const char *file, int line)
399	414	{
400		- warn_slowpath_common(file, line, __builtin_return_address(0), NULL);
	415	+ warn_slowpath_common(file, line, __builtin_return_address(0),
	416	+ TAINT_WARN, NULL);
401	417	}
402	418	EXPORT_SYMBOL(warn_slowpath_null);
403	419	#endif
...	...	@@ -165,7 +165,7 @@
165	165	(void *)bugaddr);
166	166
167	167	show_regs(regs);
168		- add_taint(TAINT_WARN);
	168	+ add_taint(BUG_GET_TAINT(bug));
169	169	return BUG_TRAP_TYPE_WARN;
170	170	}
171	171