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Fix caller information for warn_slowpath_null

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Ian Campbell noticed that since "Eliminate thousands of warnings with
gcc 3.2 build" (commit 57adc4d2db) all
WARN_ON()'s currently appear to come from warn_slowpath_null(), eg:

  WARNING: at kernel/softirq.c:143 warn_slowpath_null+0x1c/0x20()

because now that warn_slowpath_null() is in the call path, the
__builtin_return_address(0) returns that, rather than the place that
caused the warning.

Fix this by splitting up the warn_slowpath_null/fmt cases differently,
using a common helper function, and getting the return address in the
right place.  This also happens to avoid the unnecessary stack usage for
the non-stdargs case, and just generally cleans things up.

Make the function name printout use %pS while at it.

Cc: 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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Linus Torvalds 2009-05-16 13:41:28 -07:00
parent b41a080fa9
commit 0f6f49a8cd
1 changed files with 20 additions and 15 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

35
kernel/panic.c
View file

@ -340,39 +340,44 @@ void oops_exit(void)
}
#ifdef WANT_WARN_ON_SLOWPATH
void warn_slowpath_fmt(const char *file, int line, const char *fmt, ...)
{
struct slowpath_args {
const char *fmt;
va_list args;
char function[KSYM_SYMBOL_LEN];
unsigned long caller = (unsigned long)__builtin_return_address(0);
};
static void warn_slowpath_common(const char *file, int line, void *caller, struct slowpath_args *args)
{
const char *board;
sprint_symbol(function, caller);
printk(KERN_WARNING "------------[ cut here ]------------\n");
printk(KERN_WARNING "WARNING: at %s:%d %s()\n", file,
line, function);
printk(KERN_WARNING "WARNING: at %s:%d %pS()\n", file, line, caller);
board = dmi_get_system_info(DMI_PRODUCT_NAME);
if (board)
printk(KERN_WARNING "Hardware name: %s\n", board);
if (*fmt) {
va_start(args, fmt);
vprintk(fmt, args);
va_end(args);
}
if (args)
vprintk(args->fmt, args->args);
print_modules();
dump_stack();
print_oops_end_marker();
add_taint(TAINT_WARN);
}
void warn_slowpath_fmt(const char *file, int line, const char *fmt, ...)
{
struct slowpath_args args;
args.fmt = fmt;
va_start(args.args, fmt);
warn_slowpath_common(file, line, __builtin_return_address(0), &args);
va_end(args.args);
}
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_common(file, line, __builtin_return_address(0), NULL);
}
EXPORT_SYMBOL(warn_slowpath_null);
#endif