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authorJesse Brandeburg <jesse.brandeburg@intel.com>2020-06-05 02:50:27 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2020-06-05 05:06:25 +0300
commitc348c16305280fe3e6c1186378f96c8634c149f9 (patch)
treeaa53fa861170b36756d7d1aa14c1ce4c00089da5 /lib/Kconfig.debug
parent63d7f8167fe65891617d5eca6314eca46029955c (diff)
downloadlinux-c348c16305280fe3e6c1186378f96c8634c149f9.tar.xz
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 'lib/Kconfig.debug')
-rw-r--r--lib/Kconfig.debug13
1 files changed, 13 insertions, 0 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 30302c9b0f83..b9a450b1fbf7 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -2022,6 +2022,19 @@ config TEST_LKM
If unsure, say N.
+config TEST_BITOPS
+ tristate "Test module for compilation of clear_bit/set_bit operations"
+ depends on m
+ help
+ This builds the "test_bitops" module that is much like the
+ TEST_LKM module except that it does a basic exercise of the
+ clear_bit and set_bit macros to make sure there are no compiler
+ warnings from C=1 sparse checker or -Wextra compilations. It has
+ no dependencies and doesn't run or load unless explicitly requested
+ by name. for example: modprobe test_bitops.
+
+ If unsure, say N.
+
config TEST_VMALLOC
tristate "Test module for stress/performance analysis of vmalloc allocator"
default n