Messages in this thread | | | From | Christian Borntraeger <> | Subject | [PATCH/RFC 0/2] followup change for READ_ONCE/WRITE_ONCE | Date | Wed, 25 Mar 2015 14:15:34 +0100 |
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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
In addition this also causes a compiler error on s390 allyesconfig with GCOV enabled. (fixed in patch 1).
Christian Borntraeger (2): s390/ebdic: disable gcov on ebcdic.o compiler.h: Fix word size check for READ/WRITE_ONCE
arch/s390/kernel/Makefile | 4 ++++ include/linux/compiler.h | 5 +---- 2 files changed, 5 insertions(+), 4 deletions(-)
-- 2.1.4
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