Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) # SPDX-License-Identifier: GPL-2.0-only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3) config HAVE_ARCH_KCSAN
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4) 	bool
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6) config HAVE_KCSAN_COMPILER
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7) 	def_bool (CC_IS_CLANG && $(cc-option,-fsanitize=thread -mllvm -tsan-distinguish-volatile=1)) || \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8) 		 (CC_IS_GCC && $(cc-option,-fsanitize=thread --param tsan-distinguish-volatile=1))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9) 	help
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10) 	  For the list of compilers that support KCSAN, please see
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) 	  <file:Documentation/dev-tools/kcsan.rst>.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) config KCSAN_KCOV_BROKEN
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) 	def_bool KCOV && CC_HAS_SANCOV_TRACE_PC
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) 	depends on CC_IS_CLANG
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) 	depends on !$(cc-option,-Werror=unused-command-line-argument -fsanitize=thread -fsanitize-coverage=trace-pc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) 	help
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) 	  Some versions of clang support either KCSAN and KCOV but not the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) 	  combination of the two.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) 	  See https://bugs.llvm.org/show_bug.cgi?id=45831 for the status
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) 	  in newer releases.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) menuconfig KCSAN
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) 	bool "KCSAN: dynamic data race detector"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) 	depends on HAVE_ARCH_KCSAN && HAVE_KCSAN_COMPILER
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) 	depends on DEBUG_KERNEL && !KASAN
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) 	depends on !KCSAN_KCOV_BROKEN
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) 	select STACKTRACE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) 	help
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) 	  The Kernel Concurrency Sanitizer (KCSAN) is a dynamic
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) 	  data-race detector that relies on compile-time instrumentation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) 	  KCSAN uses a watchpoint-based sampling approach to detect races.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) 	  While KCSAN's primary purpose is to detect data races, it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) 	  also provides assertions to check data access constraints.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) 	  These assertions can expose bugs that do not manifest as
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) 	  data races.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) 	  See <file:Documentation/dev-tools/kcsan.rst> for more details.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) if KCSAN
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) # Compiler capabilities that should not fail the test if they are unavailable.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) config CC_HAS_TSAN_COMPOUND_READ_BEFORE_WRITE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) 	def_bool (CC_IS_CLANG && $(cc-option,-fsanitize=thread -mllvm -tsan-compound-read-before-write=1)) || \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) 		 (CC_IS_GCC && $(cc-option,-fsanitize=thread --param tsan-compound-read-before-write=1))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) config KCSAN_VERBOSE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) 	bool "Show verbose reports with more information about system state"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) 	depends on PROVE_LOCKING
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) 	help
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) 	  If enabled, reports show more information about the system state that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 	  may help better analyze and debug races. This includes held locks and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 	  IRQ trace events.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) 	  While this option should generally be benign, we call into more
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 	  external functions on report generation; if a race report is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) 	  generated from any one of them, system stability may suffer due to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) 	  deadlocks or recursion.  If in doubt, say N.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) config KCSAN_DEBUG
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) 	bool "Debugging of KCSAN internals"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) config KCSAN_SELFTEST
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) 	bool "Perform short selftests on boot"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) 	default y
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 	help
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 	  Run KCSAN selftests on boot. On test failure, causes the kernel to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) 	  panic. Recommended to be enabled, ensuring critical functionality
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) 	  works as intended.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) config KCSAN_TEST
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 	tristate "KCSAN test for integrated runtime behaviour"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 	depends on TRACEPOINTS && KUNIT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 	select TORTURE_TEST
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 	help
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 	  KCSAN test focusing on behaviour of the integrated runtime. Tests
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 	  various race scenarios, and verifies the reports generated to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 	  console. Makes use of KUnit for test organization, and the Torture
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 	  framework for test thread control.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 	  Each test case may run at least up to KCSAN_REPORT_ONCE_IN_MS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 	  milliseconds. Test run duration may be optimized by building the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 	  kernel and KCSAN test with KCSAN_REPORT_ONCE_IN_MS set to a lower
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 	  than default value.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 	  Say Y here if you want the test to be built into the kernel and run
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 	  during boot; say M if you want the test to build as a module; say N
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 	  if you are unsure.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) config KCSAN_EARLY_ENABLE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 	bool "Early enable during boot"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 	default y
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 	help
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 	  If KCSAN should be enabled globally as soon as possible. KCSAN can
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 	  later be enabled/disabled via debugfs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) config KCSAN_NUM_WATCHPOINTS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 	int "Number of available watchpoints"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 	default 64
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 	help
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 	  Total number of available watchpoints. An address range maps into a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 	  specific watchpoint slot as specified in kernel/kcsan/encoding.h.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 	  Although larger number of watchpoints may not be usable due to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 	  limited number of CPUs, a larger value helps to improve performance
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 	  due to reducing cache-line contention. The chosen default is a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 	  conservative value; we should almost never observe "no_capacity"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 	  events (see /sys/kernel/debug/kcsan).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) config KCSAN_UDELAY_TASK
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 	int "Delay in microseconds (for tasks)"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 	default 80
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 	help
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 	  For tasks, the microsecond delay after setting up a watchpoint.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) config KCSAN_UDELAY_INTERRUPT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 	int "Delay in microseconds (for interrupts)"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) 	default 20
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) 	help
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) 	  For interrupts, the microsecond delay after setting up a watchpoint.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) 	  Interrupts have tighter latency requirements, and their delay should
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 	  be lower than for tasks.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) config KCSAN_DELAY_RANDOMIZE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 	bool "Randomize above delays"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 	default y
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) 	help
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 	  If delays should be randomized, where the maximum is KCSAN_UDELAY_*.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) 	  If false, the chosen delays are always the KCSAN_UDELAY_* values
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 	  as defined above.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) config KCSAN_SKIP_WATCH
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 	int "Skip instructions before setting up watchpoint"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 	default 4000
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 	help
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 	  The number of per-CPU memory operations to skip, before another
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 	  watchpoint is set up, i.e. one in KCSAN_WATCH_SKIP per-CPU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 	  memory operations are used to set up a watchpoint. A smaller value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 	  results in more aggressive race detection, whereas a larger value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 	  improves system performance at the cost of missing some races.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) config KCSAN_SKIP_WATCH_RANDOMIZE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 	bool "Randomize watchpoint instruction skip count"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) 	default y
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 	help
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 	  If instruction skip count should be randomized, where the maximum is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 	  KCSAN_WATCH_SKIP. If false, the chosen value is always
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 	  KCSAN_WATCH_SKIP.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) config KCSAN_INTERRUPT_WATCHER
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 	bool "Interruptible watchers"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) 	help
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 	  If enabled, a task that set up a watchpoint may be interrupted while
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) 	  delayed. This option will allow KCSAN to detect races between
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 	  interrupted tasks and other threads of execution on the same CPU.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 	  Currently disabled by default, because not all safe per-CPU access
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 	  primitives and patterns may be accounted for, and therefore could
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 	  result in false positives.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) config KCSAN_REPORT_ONCE_IN_MS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 	int "Duration in milliseconds, in which any given race is only reported once"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 	default 3000
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 	help
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 	  Any given race is only reported once in the defined time window.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 	  Different races may still generate reports within a duration that is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 	  smaller than the duration defined here. This allows rate limiting
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 	  reporting to avoid flooding the console with reports.  Setting this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 	  to 0 disables rate limiting.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) # The main purpose of the below options is to control reported data races (e.g.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) # in fuzzer configs), and are not expected to be switched frequently by other
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) # users. We could turn some of them into boot parameters, but given they should
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) # not be switched normally, let's keep them here to simplify configuration.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) #
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) # The defaults below are chosen to be very conservative, and may miss certain
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) # bugs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) config KCSAN_REPORT_RACE_UNKNOWN_ORIGIN
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) 	bool "Report races of unknown origin"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 	default y
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 	help
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 	  If KCSAN should report races where only one access is known, and the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 	  conflicting access is of unknown origin. This type of race is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 	  reported if it was only possible to infer a race due to a data value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 	  change while an access is being delayed on a watchpoint.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) config KCSAN_REPORT_VALUE_CHANGE_ONLY
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 	bool "Only report races where watcher observed a data value change"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 	default y
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 	help
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 	  If enabled and a conflicting write is observed via a watchpoint, but
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 	  the data value of the memory location was observed to remain
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 	  unchanged, do not report the data race.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) config KCSAN_ASSUME_PLAIN_WRITES_ATOMIC
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) 	bool "Assume that plain aligned writes up to word size are atomic"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) 	default y
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) 	help
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) 	  Assume that plain aligned writes up to word size are atomic by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) 	  default, and also not subject to other unsafe compiler optimizations
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) 	  resulting in data races. This will cause KCSAN to not report data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 	  races due to conflicts where the only plain accesses are aligned
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) 	  writes up to word size: conflicts between marked reads and plain
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) 	  aligned writes up to word size will not be reported as data races;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) 	  notice that data races between two conflicting plain aligned writes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) 	  will also not be reported.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) config KCSAN_IGNORE_ATOMICS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) 	bool "Do not instrument marked atomic accesses"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) 	help
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) 	  Never instrument marked atomic accesses. This option can be used for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) 	  additional filtering. Conflicting marked atomic reads and plain
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) 	  writes will never be reported as a data race, however, will cause
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) 	  plain reads and marked writes to result in "unknown origin" reports.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) 	  If combined with CONFIG_KCSAN_REPORT_RACE_UNKNOWN_ORIGIN=n, data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) 	  races where at least one access is marked atomic will never be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) 	  reported.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) 	  Similar to KCSAN_ASSUME_PLAIN_WRITES_ATOMIC, but including unaligned
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) 	  accesses, conflicting marked atomic reads and plain writes will not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) 	  be reported as data races; however, unlike that option, data races
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) 	  due to two conflicting plain writes will be reported (aligned and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) 	  unaligned, if CONFIG_KCSAN_ASSUME_PLAIN_WRITES_ATOMIC=n).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) endif # KCSAN