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authorMarco Elver <elver@google.com>2020-02-04 18:21:11 +0100
committerIngo Molnar <mingo@kernel.org>2020-03-21 09:42:21 +0100
commita249a73231e2e30944b948c5351025e5ff65f6d1 (patch)
tree20da47907328cf687c874c123661cec4147a2a00 /lib
parentkcsan: Add option to assume plain aligned writes up to word size are atomic (diff)
downloadlinux-a249a73231e2e30944b948c5351025e5ff65f6d1.tar.xz
linux-a249a73231e2e30944b948c5351025e5ff65f6d1.zip
kcsan: Clarify Kconfig option KCSAN_IGNORE_ATOMICS
Clarify difference between options KCSAN_IGNORE_ATOMICS and KCSAN_ASSUME_PLAIN_WRITES_ATOMIC in help text. Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'lib')
-rw-r--r--lib/Kconfig.kcsan16
1 files changed, 13 insertions, 3 deletions
diff --git a/lib/Kconfig.kcsan b/lib/Kconfig.kcsan
index 66126853dab0..020ac63e4361 100644
--- a/lib/Kconfig.kcsan
+++ b/lib/Kconfig.kcsan
@@ -132,8 +132,18 @@ config KCSAN_ASSUME_PLAIN_WRITES_ATOMIC
config KCSAN_IGNORE_ATOMICS
bool "Do not instrument marked atomic accesses"
help
- If enabled, never instruments marked atomic accesses. This results in
- not reporting data races where one access is atomic and the other is
- a plain access.
+ Never instrument marked atomic accesses. This option can be used for
+ additional filtering. Conflicting marked atomic reads and plain
+ writes will never be reported as a data race, however, will cause
+ plain reads and marked writes to result in "unknown origin" reports.
+ If combined with CONFIG_KCSAN_REPORT_RACE_UNKNOWN_ORIGIN=n, data
+ races where at least one access is marked atomic will never be
+ reported.
+
+ Similar to KCSAN_ASSUME_PLAIN_WRITES_ATOMIC, but including unaligned
+ accesses, conflicting marked atomic reads and plain writes will not
+ be reported as data races; however, unlike that option, data races
+ due to two conflicting plain writes will be reported (aligned and
+ unaligned, if CONFIG_KCSAN_ASSUME_PLAIN_WRITES_ATOMIC=n).
endif # KCSAN