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authorIngo Molnar <mingo@elte.hu>2009-07-03 13:06:01 +0200
committerIngo Molnar <mingo@elte.hu>2009-07-03 13:26:45 +0200
commit3217120873598533234b6dedda9c371ce30001d0 (patch)
tree3aed0bb4a98bbe2553d9216fa6c965be86e3d8fb /arch
parent3ac805d2afd3fa4a07cb5bcf352fd7fa83f28935 (diff)
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x86: atomic64: Make atomic_read() type-safe
Linus noticed that atomic64_xchg() uses atomic_read(), which happens to work because atomic_read() is a macro so the .counter value gets u64-read on 32-bit too - but this is really bogus and serious bugs are waiting to happen. Change atomic_read() to be a type-safe inline, and this exposes the atomic64 bogosity as well: arch/x86/lib/atomic64_32.c: In function ‘atomic64_xchg’: arch/x86/lib/atomic64_32.c:39: warning: passing argument 1 of ‘atomic_read’ from incompatible pointer type Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: David Howells <dhowells@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> LKML-Reference: <alpine.LFD.2.01.0907021653030.3210@localhost.localdomain> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/include/asm/atomic_32.h5
1 files changed, 4 insertions, 1 deletions
diff --git a/arch/x86/include/asm/atomic_32.h b/arch/x86/include/asm/atomic_32.h
index 311a43e47c0b..b551bb1ae3cf 100644
--- a/arch/x86/include/asm/atomic_32.h
+++ b/arch/x86/include/asm/atomic_32.h
@@ -19,7 +19,10 @@
*
* Atomically reads the value of @v.
*/
-#define atomic_read(v) ((v)->counter)
+static inline int atomic_read(const atomic_t *v)
+{
+ return v->counter;
+}
/**
* atomic_set - set atomic variable