From b2be05273a1744d175bf4b67f6665637bb9ac7a8 Mon Sep 17 00:00:00 2001 From: Ben Hutchings Date: Sat, 3 Apr 2010 19:34:56 +0100 Subject: [PATCH] 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 Acked-by: Helge Deller Tested-by: Paul Mundt Signed-off-by: David Woodhouse --- Documentation/oops-tracing.txt | 1 + arch/parisc/include/asm/bug.h | 8 ++++---- arch/powerpc/include/asm/bug.h | 6 +++--- arch/s390/include/asm/bug.h | 8 ++++---- arch/sh/include/asm/bug.h | 4 ++-- include/asm-generic/bug.h | 34 ++++++++++++++++++++++++++++++++-- kernel/panic.c | 24 ++++++++++++++++++++---- lib/bug.c | 2 +- 8 files changed, 67 insertions(+), 20 deletions(-) diff --git a/Documentation/oops-tracing.txt b/Documentation/oops-tracing.txt index c10c022b911c..069fab3ea4d6 100644 --- a/Documentation/oops-tracing.txt +++ b/Documentation/oops-tracing.txt @@ -256,6 +256,7 @@ characters, each representing a particular tainted value. 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. diff --git a/arch/parisc/include/asm/bug.h b/arch/parisc/include/asm/bug.h index 75e46c557a16..72cfdb0cfdd1 100644 --- a/arch/parisc/include/asm/bug.h +++ b/arch/parisc/include/asm/bug.h @@ -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 diff --git a/arch/powerpc/include/asm/bug.h b/arch/powerpc/include/asm/bug.h index 2c15212e1700..065c590c991d 100644 --- a/arch/powerpc/include/asm/bug.h +++ b/arch/powerpc/include/asm/bug.h @@ -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)); \ } \ diff --git a/arch/s390/include/asm/bug.h b/arch/s390/include/asm/bug.h index 9beeb9db9b23..bf90d1fd97a5 100644 --- a/arch/s390/include/asm/bug.h +++ b/arch/s390/include/asm/bug.h @@ -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); \ }) diff --git a/arch/sh/include/asm/bug.h b/arch/sh/include/asm/bug.h index d02c01b3e6b9..6323f864d111 100644 --- a/arch/sh/include/asm/bug.h +++ b/arch/sh/include/asm/bug.h @@ -48,7 +48,7 @@ do { \ "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 @@ do { \ : "n" (TRAPA_BUG_OPCODE), \ "i" (__FILE__), \ "i" (__LINE__), \ - "i" (BUGFLAG_WARNING), \ + "i" (BUGFLAG_TAINT(taint)), \ "i" (sizeof(struct bug_entry))); \ } while (0) diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h index 18c435d7c082..c2c9ba032d46 100644 --- a/include/asm-generic/bug.h +++ b/include/asm-generic/bug.h @@ -25,7 +25,10 @@ struct bug_entry { }; #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 @@ struct bug_entry { * 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 @@ extern void warn_slowpath_null(const char *file, const int line); }) #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 @@ extern void warn_slowpath_null(const char *file, const int line); }) #endif +#define WARN_TAINT(condition, taint, format...) WARN_ON(condition) + #endif #define WARN_ON_ONCE(condition) ({ \ @@ -132,6 +152,16 @@ extern void warn_slowpath_null(const char *file, const int line); 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); \ +}) + #define WARN_ON_RATELIMIT(condition, state) \ WARN_ON((condition) && __ratelimit(state)) diff --git a/kernel/panic.c b/kernel/panic.c index 13d966b4c14a..8b821bce66e6 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -365,7 +365,8 @@ struct slowpath_args { 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 @@ static void warn_slowpath_common(const char *file, int line, void *caller, struc 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 @@ void warn_slowpath_fmt(const char *file, int line, const char *fmt, ...) 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 diff --git a/lib/bug.c b/lib/bug.c index 300e41afbf97..f13daf435211 100644 --- a/lib/bug.c +++ b/lib/bug.c @@ -165,7 +165,7 @@ enum bug_trap_type report_bug(unsigned long bugaddr, struct pt_regs *regs) (void *)bugaddr); show_regs(regs); - add_taint(TAINT_WARN); + add_taint(BUG_GET_TAINT(bug)); return BUG_TRAP_TYPE_WARN; }