Messages in this thread Patch in this message | | | From | Christian Borntraeger <> | Subject | [PATCH 2/2] compiler.h: Fix word size check for READ/WRITE_ONCE | Date | Wed, 25 Mar 2015 14:15:36 +0100 |
| |
Turns out that my last rework for the word size check broke it:
I originally had the size > wordsize check in __read_once_size/ /__write_once_size as empty extern function in a newly created file lib/access.c and marked it with a __compiletime_warning.
Unfortunately this broke arm rpcdefconfig due to this line CFLAGS_font.o := -Dstatic= in arch/arm/boot/compressed/Makefile. This define made it impossible for the compiler to get rid of the unused __write_once_size and __read_once_size and the linker complained about the missing data_access_exceeds_word_size as the compressed boot thing did not include lib/access.o.
So I wanted to be clever and changed data_access_exceeds_word_size to a static inline function. Turns out that this actually disabled the compiletime warning.
Next try, have it as a weak function. This actually does enable the warning. It will create an empty data_access_exceeds_word_size function in each object file, though and it will trigger a warning for arm rpcdefconfig: CC arch/arm/boot/compressed/font.o include/linux/compiler.h: In function '__write_once_size': include/linux/compiler.h:231: warning: call to 'data_access_exceeds_word_size' declared with attribute warning: data access exceeds word size and won't be atomic include/linux/compiler.h: In function '__read_once_size': include/linux/compiler.h:214: warning: call to 'data_access_exceeds_word_size' declared with attribute warning: data access exceeds word size and won't be atomic
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> --- include/linux/compiler.h | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/include/linux/compiler.h b/include/linux/compiler.h index 1b45e4a..37943c4 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -192,13 +192,10 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect); #include <uapi/linux/types.h> -static __always_inline void data_access_exceeds_word_size(void) #ifdef __compiletime_warning __compiletime_warning("data access exceeds word size and won't be atomic") #endif -; - -static __always_inline void data_access_exceeds_word_size(void) +__weak notrace void data_access_exceeds_word_size(void) { } -- 2.1.4
| |