From: Nathan Chancellor natechancellor@gmail.com
[ Upstream commit b5bb425871186303e6936fa2581521bdd1964a58 ]
Clang warns that if the default case is taken, ret will be uninitialized.
./arch/arm64/include/asm/percpu.h:196:2: warning: variable 'ret' is used uninitialized whenever switch default is taken [-Wsometimes-uninitialized] default: ^~~~~~~ ./arch/arm64/include/asm/percpu.h:200:9: note: uninitialized use occurs here return ret; ^~~ ./arch/arm64/include/asm/percpu.h:157:19: note: initialize the variable 'ret' to silence this warning unsigned long ret, loop; ^ = 0
This warning appears several times while building the erofs filesystem. While it's not strictly wrong, the BUILD_BUG will prevent this from becoming a true problem. Initialize ret to 0 in the default case right before the BUILD_BUG to silence all of these warnings.
Reported-by: Prasad Sodagudi psodagud@codeaurora.org Signed-off-by: Nathan Chancellor natechancellor@gmail.com Reviewed-by: Nick Desaulniers ndesaulniers@google.com Signed-off-by: Dennis Zhou dennis@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- arch/arm64/include/asm/percpu.h | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/arch/arm64/include/asm/percpu.h b/arch/arm64/include/asm/percpu.h index 43393208229e..d79eaa816f29 100644 --- a/arch/arm64/include/asm/percpu.h +++ b/arch/arm64/include/asm/percpu.h @@ -93,6 +93,7 @@ static inline unsigned long __percpu_##op(void *ptr, \ : [val] "Ir" (val)); \ break; \ default: \ + ret = 0; \ BUILD_BUG(); \ } \ \ @@ -122,6 +123,7 @@ static inline unsigned long __percpu_read(void *ptr, int size) ret = READ_ONCE(*(u64 *)ptr); break; default: + ret = 0; BUILD_BUG(); }
@@ -191,6 +193,7 @@ static inline unsigned long __percpu_xchg(void *ptr, unsigned long val, : [val] "r" (val)); break; default: + ret = 0; BUILD_BUG(); }