diff options
| author | Yury Norov <yury.norov@gmail.com> | 2023-07-17 12:17:03 -0700 |
|---|---|---|
| committer | Yury Norov <yury.norov@gmail.com> | 2023-07-18 13:25:37 -0700 |
| commit | 2356d198d2b4ddec24efea98271cb3be230bc787 (patch) | |
| tree | 9ae1e1509c563f1a024b3e37443d4ecd8aeed940 /lib/test_bitmap.c | |
| parent | dcb60f9c403e03133363563ac8ea5d8bba6c2be1 (diff) | |
lib/bitmap: workaround const_eval test build failure
When building with Clang, and when KASAN and GCOV_PROFILE_ALL are both
enabled, the test fails to build [1]:
>> lib/test_bitmap.c:920:2: error: call to '__compiletime_assert_239' declared with 'error' attribute: BUILD_BUG_ON failed: !__builtin_constant_p(res)
BUILD_BUG_ON(!__builtin_constant_p(res));
^
include/linux/build_bug.h:50:2: note: expanded from macro 'BUILD_BUG_ON'
BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition)
^
include/linux/build_bug.h:39:37: note: expanded from macro 'BUILD_BUG_ON_MSG'
#define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
^
include/linux/compiler_types.h:352:2: note: expanded from macro 'compiletime_assert'
_compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
^
include/linux/compiler_types.h:340:2: note: expanded from macro '_compiletime_assert'
__compiletime_assert(condition, msg, prefix, suffix)
^
include/linux/compiler_types.h:333:4: note: expanded from macro '__compiletime_assert'
prefix ## suffix(); \
^
<scratch space>:185:1: note: expanded from here
__compiletime_assert_239
Originally it was attributed to s390, which now looks seemingly wrong. The
issue is not related to bitmap code itself, but it breaks build for a given
configuration.
Disabling the const_eval test under that config may potentially hide other
bugs. Instead, workaround it by disabling GCOV for the test_bitmap unless
the compiler will get fixed.
[1] https://github.com/ClangBuiltLinux/linux/issues/1874
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202307171254.yFcH97ej-lkp@intel.com/
Fixes: dc34d5036692 ("lib: test_bitmap: add compile-time optimization/evaluations assertions")
Co-developed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Diffstat (limited to 'lib/test_bitmap.c')
| -rw-r--r-- | lib/test_bitmap.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/lib/test_bitmap.c b/lib/test_bitmap.c index 187f5b2db4cf..f2ea9f30c7c5 100644 --- a/lib/test_bitmap.c +++ b/lib/test_bitmap.c @@ -1161,6 +1161,10 @@ static void __init test_bitmap_print_buf(void) } } +/* + * FIXME: Clang breaks compile-time evaluations when KASAN and GCOV are enabled. + * To workaround it, GCOV is force-disabled in Makefile for this configuration. + */ static void __init test_bitmap_const_eval(void) { DECLARE_BITMAP(bitmap, BITS_PER_LONG); @@ -1186,11 +1190,7 @@ static void __init test_bitmap_const_eval(void) * the compiler is fixed. */ bitmap_clear(bitmap, 0, BITS_PER_LONG); -#if defined(__s390__) && defined(__clang__) - if (!const_test_bit(7, bitmap)) -#else if (!test_bit(7, bitmap)) -#endif bitmap_set(bitmap, 5, 2); /* Equals to `unsigned long bitopvar = BIT(20)` */ |