x86, atomic: atomic64_read() take a const pointer

atomic64_read() doesn't actually write anything (as far as the C environment is concerned... the CPU does actually write but that's an implementation quirk), so it should take a const pointer. This does NOT mean that it is safe to use atomic64_read() on an object in readonly storage (it will trap!) Reported-by: Andrew Morton <[email protected]> Signed-off-by: H. Peter Anvin <[email protected]> Link: http://lkml.kernel.org/r/[email protected]
vieko · Jan 10, 2012 · 8030c36 · 8030c36
1 parent da517a0
commit 8030c36
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/arch/x86/include/asm/atomic64_32.h b/arch/x86/include/asm/atomic64_32.h
@@ -82,7 +82,7 @@ static inline void atomic64_set(atomic64_t *v, long long i)
  *
  * Atomically reads the value of @v and returns it.
  */
-static inline long long atomic64_read(atomic64_t *v)
+static inline long long atomic64_read(const atomic64_t *v)
 {
 	long long r;
 	asm volatile(ATOMIC64_ALTERNATIVE(read)