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| author | Marco Elver <elver@google.com> | 2020-02-21 23:02:09 +0100 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2020-03-25 09:55:59 -0700 |
| commit | 48b1fc190a180d971fb69217c88c7247f4f2ca19 (patch) | |
| tree | 6b3408d62d095a068afc089cfbfd3f98d73cfaa5 /lib | |
| parent | f5d2313bd3c540be405c4977a63840cd6d0167b5 (diff) | |
| download | linux-48b1fc190a180d971fb69217c88c7247f4f2ca19.tar.gz linux-48b1fc190a180d971fb69217c88c7247f4f2ca19.tar.bz2 linux-48b1fc190a180d971fb69217c88c7247f4f2ca19.zip | |
kcsan: Add option to allow watcher interruptions
Add option to allow interrupts while a watchpoint is set up. This can be
enabled either via CONFIG_KCSAN_INTERRUPT_WATCHER or via the boot
parameter 'kcsan.interrupt_watcher=1'.
Note that, currently not all safe per-CPU access primitives and patterns
are accounted for, which could result in false positives. For example,
asm-generic/percpu.h uses plain operations, which by default are
instrumented. On interrupts and subsequent accesses to the same
variable, KCSAN would currently report a data race with this option.
Therefore, this option should currently remain disabled by default, but
may be enabled for specific test scenarios.
To avoid new warnings, changes all uses of smp_processor_id() to use the
raw version (as already done in kcsan_found_watchpoint()). The exact SMP
processor id is for informational purposes in the report, and
correctness is not affected.
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Kconfig.kcsan | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/lib/Kconfig.kcsan b/lib/Kconfig.kcsan index f0b791143c6a..081ed2e1bf7b 100644 --- a/lib/Kconfig.kcsan +++ b/lib/Kconfig.kcsan @@ -88,6 +88,17 @@ 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 |