Merge branch 'kcsan-for-tip' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into locking/kcsan

Pull KCSAN updates from Paul McKenney.

1 files changed, 32 insertions, 7 deletions

diff --git a/lib/Kconfig.kcsan b/lib/Kconfig.kcsan
index f0b791143c6a..689b6b81f272 100644
--- a/lib/Kconfig.kcsan
+++ b/lib/Kconfig.kcsan
@@ -4,22 +4,36 @@ config HAVE_ARCH_KCSAN
 	bool
 
 menuconfig KCSAN
-	bool "KCSAN: dynamic race detector"
+	bool "KCSAN: dynamic data race detector"
 	depends on HAVE_ARCH_KCSAN && DEBUG_KERNEL && !KASAN
 	select STACKTRACE
 	help
-	  The Kernel Concurrency Sanitizer (KCSAN) is a dynamic race detector,
-	  which relies on compile-time instrumentation, and uses a
-	  watchpoint-based sampling approach to detect races.
+	  The Kernel Concurrency Sanitizer (KCSAN) is a dynamic
+	  data-race detector that relies on compile-time instrumentation.
+	  KCSAN uses a watchpoint-based sampling approach to detect races.
 
-	  KCSAN's primary purpose is to detect data races. KCSAN can also be
-	  used to check properties, with the help of provided assertions, of
-	  concurrent code where bugs do not manifest as data races.
+	  While KCSAN's primary purpose is to detect data races, it
+	  also provides assertions to check data access constraints.
+	  These assertions can expose bugs that do not manifest as
+	  data races.
 
 	  See <file:Documentation/dev-tools/kcsan.rst> for more details.
 
 if KCSAN
 
+config KCSAN_VERBOSE
+	bool "Show verbose reports with more information about system state"
+	depends on PROVE_LOCKING
+	help
+	  If enabled, reports show more information about the system state that
+	  may help better analyze and debug races. This includes held locks and
+	  IRQ trace events.
+
+	  While this option should generally be benign, we call into more
+	  external functions on report generation; if a race report is
+	  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"
 
@@ -88,6 +102,17 @@ config KCSAN_SKIP_WATCH_RANDOMIZE
 	  KCSAN_WATCH_SKIP. If false, the chosen value is always
 	  KCSAN_WATCH_SKIP.
 
+config KCSAN_INTERRUPT_WATCHER
+	bool "Interruptible watchers"
+	help
+	  If enabled, a task that set up a watchpoint may be interrupted while
+	  delayed. This option will allow KCSAN to detect races between
+	  interrupted tasks and other threads of execution on the same CPU.
+
+	  Currently disabled by default, because not all safe per-CPU access
+	  primitives and patterns may be accounted for, and therefore could
+	  result in false positives.
+
 config KCSAN_REPORT_ONCE_IN_MS
 	int "Duration in milliseconds, in which any given race is only reported once"
 	default 3000