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| author |   Jesse Brandeburg <jesse.brandeburg@intel.com> | 2020-06-04 16:50:27 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-04 19:06:25 -0700 |
| commit | c348c16305280fe3e6c1186378f96c8634c149f9 (patch) | |
| tree | aa53fa861170b36756d7d1aa14c1ce4c00089da5 /tools/testing/selftests/lib | |
| parent | lib/flex_proportions.c: cleanup __fprop_inc_percpu_max (diff) | |
| download | wireguard-linux-c348c16305280fe3e6c1186378f96c8634c149f9.tar.xz wireguard-linux-c348c16305280fe3e6c1186378f96c8634c149f9.zip | |
lib: make a test module with set/clear bit
Test some bit clears/sets to make sure assembly doesn't change, and that
the set_bit and clear_bit functions work and don't cause sparse warnings.
Instruct Kbuild to build this file with extra warning level -Wextra, to
catch new issues, and also doesn't hurt to build with C=1.
This was used to test changes to arch/x86/include/asm/bitops.h.
In particular, sparse (C=1) was very concerned when the last bit before a
natural boundary, like 7, or 31, was being tested, as this causes sign
extension (0xffffff7f) for instance when clearing bit 7.
Recommended usage:
make defconfig
scripts/config -m CONFIG_TEST_BITOPS
make modules_prepare
make C=1 W=1 lib/test_bitops.ko
objdump -S -d lib/test_bitops.ko
insmod lib/test_bitops.ko
rmmod lib/test_bitops.ko
<check dmesg>, there should be no compiler/sparse warnings and no
error messages in log.
Link: http://lkml.kernel.org/r/20200310221747.2848474-2-jesse.brandeburg@intel.com
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
CcL Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'tools/testing/selftests/lib')
| -rw-r--r-- | tools/testing/selftests/lib/config | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/tools/testing/selftests/lib/config b/tools/testing/selftests/lib/config index 14a77ea4a8da..b80ee3f6e265 100644 --- a/tools/testing/selftests/lib/config +++ b/tools/testing/selftests/lib/config @@ -2,3 +2,4 @@ CONFIG_TEST_PRINTF=m CONFIG_TEST_BITMAP=m CONFIG_PRIME_NUMBERS=m CONFIG_TEST_STRSCPY=m +CONFIG_TEST_BITOPS=m |