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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2021-09-02 13:00:15 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-09-02 13:00:15 -0700 |
| commit | aa829778b16f15266fefe2640f04931b16ce39c0 (patch) | |
| tree | eb2bc83c849f0461ffd09d4cd5e79036ff469551 /Documentation | |
| parent | aef4892a63c248c31718d23941536b86829a49f0 (diff) | |
| parent | 4812c9111220b0af00f7a436cc02ffaed289962c (diff) | |
Merge tag 'locking-debug-2021-09-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull memory model updates from Ingo Molnar:
"LKMM updates:
- Update documentation and code example
KCSAN updates:
- Introduce CONFIG_KCSAN_STRICT (which RCU uses)
- Optimize use of get_ctx() by kcsan_found_watchpoint()
- Rework atomic.h into permissive.h
- Add the ability to ignore writes that change only one bit of a
given data-racy variable.
- Improve comments"
* tag 'locking-debug-2021-09-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
tools/memory-model: Document data_race(READ_ONCE())
tools/memory-model: Heuristics using data_race() must handle all values
tools/memory-model: Add example for heuristic lockless reads
tools/memory-model: Make read_foo_diagnostic() more clearly diagnostic
kcsan: Make strict mode imply interruptible watchers
kcsan: permissive: Ignore data-racy 1-bit value changes
kcsan: Print if strict or non-strict during init
kcsan: Rework atomic.h into permissive.h
kcsan: Reduce get_ctx() uses in kcsan_found_watchpoint()
kcsan: Introduce CONFIG_KCSAN_STRICT
kcsan: Remove CONFIG_KCSAN_DEBUG
kcsan: Improve some Kconfig comments
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/dev-tools/kcsan.rst | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/Documentation/dev-tools/kcsan.rst b/Documentation/dev-tools/kcsan.rst index 6a600cf8430b..7db43c7c09b8 100644 --- a/Documentation/dev-tools/kcsan.rst +++ b/Documentation/dev-tools/kcsan.rst @@ -127,6 +127,18 @@ Kconfig options: causes KCSAN to not report data races due to conflicts where the only plain accesses are aligned writes up to word size. +* ``CONFIG_KCSAN_PERMISSIVE``: Enable additional permissive rules to ignore + certain classes of common data races. Unlike the above, the rules are more + complex involving value-change patterns, access type, and address. This + option depends on ``CONFIG_KCSAN_REPORT_VALUE_CHANGE_ONLY=y``. For details + please see the ``kernel/kcsan/permissive.h``. Testers and maintainers that + only focus on reports from specific subsystems and not the whole kernel are + recommended to disable this option. + +To use the strictest possible rules, select ``CONFIG_KCSAN_STRICT=y``, which +configures KCSAN to follow the Linux-kernel memory consistency model (LKMM) as +closely as possible. + DebugFS interface ~~~~~~~~~~~~~~~~~ |