Messages in this thread Patch in this message | | | From | Ian Campbell <> | Subject | [PATCH] Fix print out of function which called WARN_ON() | Date | Fri, 15 May 2009 17:17:16 +0100 |
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All WARN_ON()'s currently appear to come from warn_slowpath_null e.g.: WARNING: at kernel/softirq.c:143 warn_slowpath_null+0x1c/0x20()
This is because since:
commit 57adc4d2dbf968fdbe516359688094eef4d46581 Author: Andi Kleen <andi@firstfloor.org> Date: Wed May 6 16:02:53 2009 -0700
Eliminate thousands of warnings with gcc 3.2 build
the caller of warn_slowpath_fmt really is warn_flowpath_null not the interesting caller next up the chain. Since __builtin_return_address(X) for X > 0 is not reliable, pass the real caller as an argument to warn_slowpath_fmt.
[If there was a __builtin_this_address() I would use that for the WARN() case for consistency, I don't know of such a thing though]
Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Hugh Dickins <hugh@veritas.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> --- include/asm-generic/bug.h | 5 +++-- kernel/panic.c | 11 ++++++++--- 2 files changed, 11 insertions(+), 5 deletions(-)
diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h index 4f4f6e9..39d8dbd 100644 --- a/include/asm-generic/bug.h +++ b/include/asm-generic/bug.h @@ -59,12 +59,13 @@ struct bug_entry { #ifndef __WARN #ifndef __ASSEMBLY__ extern void warn_slowpath_fmt(const char *file, const int line, - const char *fmt, ...) __attribute__((format(printf, 3, 4))); + unsigned long caller, + 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(arg...) warn_slowpath_fmt(__FILE__, __LINE__, 0UL, arg) #else #define __WARN_printf(arg...) do { printk(arg); __WARN(); } while (0) #endif diff --git a/kernel/panic.c b/kernel/panic.c index 874ecf1..4e1d746 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -340,13 +340,16 @@ void oops_exit(void) } #ifdef WANT_WARN_ON_SLOWPATH -void warn_slowpath_fmt(const char *file, int line, const char *fmt, ...) +void warn_slowpath_fmt(const char *file, int line, unsigned long caller, + const char *fmt, ...) { va_list args; char function[KSYM_SYMBOL_LEN]; - unsigned long caller = (unsigned long)__builtin_return_address(0); const char *board; + if (!caller) + caller = (unsigned long)__builtin_return_address(0); + sprint_symbol(function, caller); printk(KERN_WARNING "------------[ cut here ]------------\n"); @@ -372,7 +375,9 @@ EXPORT_SYMBOL(warn_slowpath_fmt); void warn_slowpath_null(const char *file, int line) { static const char *empty = ""; - warn_slowpath_fmt(file, line, empty); + warn_slowpath_fmt(file, line, + (unsigned long)__builtin_return_address(0), + empty); } EXPORT_SYMBOL(warn_slowpath_null); #endif -- 1.5.6.5
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