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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2022-01-11 20:51:26 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-01-11 20:51:26 +0300 |
| commit | 1be5bdf8cd5a194d981e65687367b0828c839c37 (patch) | |
| tree | d6560826c211fd7a4ddcc1d45040dab123271df8 /lib | |
| parent | 1c824bf768d69fce36de748c60c7197a2b838944 (diff) | |
| parent | b473a3891c46393e9c4ccb4e3197d7fb259c7100 (diff) | |
| download | linux-1be5bdf8cd5a194d981e65687367b0828c839c37.tar.xz | |
Merge tag 'kcsan.2022.01.09a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu
Pull KCSAN updates from Paul McKenney:
"This provides KCSAN fixes and also the ability to take memory barriers
into account for weakly-ordered systems. This last can increase the
probability of detecting certain types of data races"
* tag 'kcsan.2022.01.09a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (29 commits)
kcsan: Only test clear_bit_unlock_is_negative_byte if arch defines it
kcsan: Avoid nested contexts reading inconsistent reorder_access
kcsan: Turn barrier instrumentation into macros
kcsan: Make barrier tests compatible with lockdep
kcsan: Support WEAK_MEMORY with Clang where no objtool support exists
compiler_attributes.h: Add __disable_sanitizer_instrumentation
objtool, kcsan: Remove memory barrier instrumentation from noinstr
objtool, kcsan: Add memory barrier instrumentation to whitelist
sched, kcsan: Enable memory barrier instrumentation
mm, kcsan: Enable barrier instrumentation
x86/qspinlock, kcsan: Instrument barrier of pv_queued_spin_unlock()
x86/barriers, kcsan: Use generic instrumentation for non-smp barriers
asm-generic/bitops, kcsan: Add instrumentation for barriers
locking/atomics, kcsan: Add instrumentation for barriers
locking/barriers, kcsan: Support generic instrumentation
locking/barriers, kcsan: Add instrumentation for barriers
kcsan: selftest: Add test case to check memory barrier instrumentation
kcsan: Ignore GCC 11+ warnings about TSan runtime support
kcsan: test: Add test cases for memory barrier instrumentation
kcsan: test: Match reordered or normal accesses
...
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Kconfig.kcsan | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/lib/Kconfig.kcsan b/lib/Kconfig.kcsan index e0a93ffdef30..63b70b8c5551 100644 --- a/lib/Kconfig.kcsan +++ b/lib/Kconfig.kcsan @@ -191,6 +191,26 @@ config KCSAN_STRICT closely aligns with the rules defined by the Linux-kernel memory consistency model (LKMM). +config KCSAN_WEAK_MEMORY + bool "Enable weak memory modeling to detect missing memory barriers" + default y + depends on KCSAN_STRICT + # We can either let objtool nop __tsan_func_{entry,exit}() and builtin + # atomics instrumentation in .noinstr.text, or use a compiler that can + # implement __no_kcsan to really remove all instrumentation. + depends on STACK_VALIDATION || CC_IS_GCC || CLANG_VERSION >= 140000 + help + Enable support for modeling a subset of weak memory, which allows + detecting a subset of data races due to missing memory barriers. + + Depends on KCSAN_STRICT, because the options strenghtening certain + plain accesses by default (depending on !KCSAN_STRICT) reduce the + ability to detect any data races invoving reordered accesses, in + particular reordered writes. + + Weak memory modeling relies on additional instrumentation and may + affect performance. + config KCSAN_REPORT_VALUE_CHANGE_ONLY bool "Only report races where watcher observed a data value change" default y |