diff options
authorArjan van de Ven <arjan@infradead.org>2008-01-30 13:32:50 +0100
committerIngo Molnar <mingo@elte.hu>2008-01-30 13:32:50 +0100
commit79b4cc5ee7a8086ac2c9c0afa52e6d687ce1ffef (patch)
parent3a6a62f96f168d192fb0cc9c0b5ee2584740b32d (diff)
debug: move WARN_ON() out of line
A quick grep shows that there are currently 1145 instances of WARN_ON in the kernel. Currently, WARN_ON is pretty much entirely inlined, which makes it hard to enhance it without growing the size of the kernel (and getting Andrew unhappy). This patch build on top of Olof's patch that introduces __WARN, and places the slowpath out of line. It also uses Ingo's suggestion to not use __FUNCTION__ but to use kallsyms to do the lookup; this saves a ton of extra space since gcc doesn't need to store the function string twice now: 3936367 833603 624736 5394706 525112 vmlinux.before 3917508 833603 624736 5375847 520767 vmlinux-slowpath 15Kb savings... Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> CC: Andrew Morton <akpm@linux-foundation.org> CC: Olof Johansson <olof@lixom.net> Acked-by: Matt Meckall <mpm@selenic.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2 files changed, 20 insertions, 5 deletions
diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h
index 1a0e1a7684b..2632328d864 100644
--- a/include/asm-generic/bug.h
+++ b/include/asm-generic/bug.h
@@ -32,11 +32,11 @@ struct bug_entry {
#ifndef __WARN
-#define __WARN() do { \
- printk("WARNING: at %s:%d %s()\n", __FILE__, \
- __LINE__, __FUNCTION__); \
- dump_stack(); \
-} while (0)
+#ifndef __ASSEMBLY__
+extern void warn_on_slowpath(const char *file, const int line);
+#define __WARN() warn_on_slowpath(__FILE__, __LINE__)
#ifndef WARN_ON
diff --git a/kernel/panic.c b/kernel/panic.c
index da4d6bac270..0ebea438278 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -20,6 +20,7 @@
#include <linux/kexec.h>
#include <linux/debug_locks.h>
#include <linux/random.h>
+#include <linux/kallsyms.h>
int panic_on_oops;
int tainted;
@@ -292,6 +293,20 @@ void oops_exit(void)
(unsigned long long)oops_id);
+void warn_on_slowpath(const char *file, int line)
+ char function[KSYM_SYMBOL_LEN];
+ unsigned long caller = (unsigned long) __builtin_return_address(0);
+ sprint_symbol(function, caller);
+ printk(KERN_WARNING "WARNING: at %s:%d %s()\n", file,
+ line, function);
+ dump_stack();
* Called when gcc's -fstack-protector feature is used, and