Fix WARN_ON() on bitfield ops
Alexey Dobriyan noticed that the new WARN_ON() semantics that were
introduced by commit 684f978347deb42d180373ac4c427f82ef963171 (to also
return the value to be warned on) didn't compile when given a bitfield,
because the typeof doesn't work for bitfields.
So instead of the typeof trick, use an "int" variable together with a
"!!(x)" expression, as suggested by Al Viro.
To make matters more interesting, Paul Mackerras points out that that is
sub-optimal on Power, but the old asm-coded comparison seems to be buggy
anyway on 32-bit Power if the conditional was 64-bit, so I think there
are more problems there.
Regardless, the new WARN_ON() semantics may have been a bad idea. But
this at least avoids the more serious complications.
Cc: Alexey Dobriyan <adobriyan@sw.ru>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h
index 344e309..d56fedb 100644
--- a/include/asm-generic/bug.h
+++ b/include/asm-generic/bug.h
@@ -33,7 +33,7 @@
#ifndef HAVE_ARCH_WARN_ON
#define WARN_ON(condition) ({ \
- typeof(condition) __ret_warn_on = (condition); \
+ int __ret_warn_on = !!(condition); \
if (unlikely(__ret_warn_on)) { \
printk("WARNING: at %s:%d %s()\n", __FILE__, \
__LINE__, __FUNCTION__); \
@@ -54,7 +54,7 @@
#ifndef HAVE_ARCH_WARN_ON
#define WARN_ON(condition) ({ \
- typeof(condition) __ret_warn_on = (condition); \
+ int __ret_warn_on = !!(condition); \
unlikely(__ret_warn_on); \
})
#endif
@@ -62,7 +62,7 @@
#define WARN_ON_ONCE(condition) ({ \
static int __warned; \
- typeof(condition) __ret_warn_once = (condition); \
+ int __ret_warn_once = !!(condition); \
\
if (unlikely(__ret_warn_once)) \
if (WARN_ON(!__warned)) \