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authorLinus Torvalds2022-01-11 09:51:26 -0800
committerLinus Torvalds2022-01-11 09:51:26 -0800
commit1be5bdf8cd5a194d981e65687367b0828c839c37 (patch)
treed6560826c211fd7a4ddcc1d45040dab123271df8 /lib/Kconfig.kcsan
parent1c824bf768d69fce36de748c60c7197a2b838944 (diff)
parentb473a3891c46393e9c4ccb4e3197d7fb259c7100 (diff)
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/Kconfig.kcsan')
-rw-r--r--lib/Kconfig.kcsan20
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