diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Kconfig.kcsan | 42 |
1 files changed, 30 insertions, 12 deletions
diff --git a/lib/Kconfig.kcsan b/lib/Kconfig.kcsan index 0440f373248e..e0a93ffdef30 100644 --- a/lib/Kconfig.kcsan +++ b/lib/Kconfig.kcsan @@ -40,10 +40,14 @@ menuconfig KCSAN if KCSAN -# Compiler capabilities that should not fail the test if they are unavailable. config CC_HAS_TSAN_COMPOUND_READ_BEFORE_WRITE def_bool (CC_IS_CLANG && $(cc-option,-fsanitize=thread -mllvm -tsan-compound-read-before-write=1)) || \ (CC_IS_GCC && $(cc-option,-fsanitize=thread --param tsan-compound-read-before-write=1)) + help + The compiler instruments plain compound read-write operations + differently (++, --, +=, -=, |=, &=, etc.), which allows KCSAN to + distinguish them from other plain accesses. This is currently + supported by Clang 12 or later. config KCSAN_VERBOSE bool "Show verbose reports with more information about system state" @@ -58,9 +62,6 @@ config KCSAN_VERBOSE generated from any one of them, system stability may suffer due to deadlocks or recursion. If in doubt, say N. -config KCSAN_DEBUG - bool "Debugging of KCSAN internals" - config KCSAN_SELFTEST bool "Perform short selftests on boot" default y @@ -149,7 +150,8 @@ config KCSAN_SKIP_WATCH_RANDOMIZE KCSAN_WATCH_SKIP. config KCSAN_INTERRUPT_WATCHER - bool "Interruptible watchers" + bool "Interruptible watchers" if !KCSAN_STRICT + default KCSAN_STRICT help If enabled, a task that set up a watchpoint may be interrupted while delayed. This option will allow KCSAN to detect races between @@ -169,13 +171,9 @@ config KCSAN_REPORT_ONCE_IN_MS reporting to avoid flooding the console with reports. Setting this to 0 disables rate limiting. -# The main purpose of the below options is to control reported data races (e.g. -# in fuzzer configs), and are not expected to be switched frequently by other -# users. We could turn some of them into boot parameters, but given they should -# not be switched normally, let's keep them here to simplify configuration. -# -# The defaults below are chosen to be very conservative, and may miss certain -# bugs. +# The main purpose of the below options is to control reported data races, and +# are not expected to be switched frequently by non-testers or at runtime. +# The defaults are chosen to be conservative, and can miss certain bugs. config KCSAN_REPORT_RACE_UNKNOWN_ORIGIN bool "Report races of unknown origin" @@ -186,9 +184,17 @@ config KCSAN_REPORT_RACE_UNKNOWN_ORIGIN reported if it was only possible to infer a race due to a data value change while an access is being delayed on a watchpoint. +config KCSAN_STRICT + bool "Strict data-race checking" + help + KCSAN will report data races with the strictest possible rules, which + closely aligns with the rules defined by the Linux-kernel memory + consistency model (LKMM). + config KCSAN_REPORT_VALUE_CHANGE_ONLY bool "Only report races where watcher observed a data value change" default y + depends on !KCSAN_STRICT help If enabled and a conflicting write is observed via a watchpoint, but the data value of the memory location was observed to remain @@ -197,6 +203,7 @@ config KCSAN_REPORT_VALUE_CHANGE_ONLY config KCSAN_ASSUME_PLAIN_WRITES_ATOMIC bool "Assume that plain aligned writes up to word size are atomic" default y + depends on !KCSAN_STRICT help Assume that plain aligned writes up to word size are atomic by default, and also not subject to other unsafe compiler optimizations @@ -209,6 +216,7 @@ config KCSAN_ASSUME_PLAIN_WRITES_ATOMIC config KCSAN_IGNORE_ATOMICS bool "Do not instrument marked atomic accesses" + depends on !KCSAN_STRICT help Never instrument marked atomic accesses. This option can be used for additional filtering. Conflicting marked atomic reads and plain @@ -224,4 +232,14 @@ config KCSAN_IGNORE_ATOMICS due to two conflicting plain writes will be reported (aligned and unaligned, if CONFIG_KCSAN_ASSUME_PLAIN_WRITES_ATOMIC=n). +config KCSAN_PERMISSIVE + bool "Enable all additional permissive rules" + depends on KCSAN_REPORT_VALUE_CHANGE_ONLY + help + Enable additional permissive rules to ignore certain classes of data + races (also see kernel/kcsan/permissive.h). None of the permissive + rules imply that such data races are generally safe, but can be used + to further reduce reported data races due to data-racy patterns + common across the kernel. + endif # KCSAN |