diff options
| author | Marco Elver <elver@google.com> | 2020-03-31 21:32:33 +0200 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2020-04-13 17:18:15 -0700 |
| commit | d071e91361bbfef524ae8abf7e560fb294d0ad64 (patch) | |
| tree | b49bfa0fec727aeb9f787950bd8bb69e2458e854 /include/linux/compiler.h | |
| parent | 01b4ff58f72dbee926077d9afa0650f6e685e866 (diff) | |
kcsan: Change data_race() to no longer require marking racing accesses
Thus far, accesses marked with data_race() would still require the
racing access to be marked in some way (be it with READ_ONCE(),
WRITE_ONCE(), or data_race() itself), as otherwise KCSAN would still
report a data race. This requirement, however, seems to be unintuitive,
and some valid use-cases demand *not* marking other accesses, as it
might hide more serious bugs (e.g. diagnostic reads).
Therefore, this commit changes data_race() to no longer require marking
racing accesses (although it's still recommended if possible).
The alternative would have been introducing another variant of
data_race(), however, since usage of data_race() already needs to be
carefully reasoned about, distinguishing between these cases likely adds
more complexity in the wrong place.
Link: https://lkml.kernel.org/r/20200331131002.GA30975@willie-the-truck
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: Qian Cai <cai@lca.pw>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'include/linux/compiler.h')
| -rw-r--r-- | include/linux/compiler.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/include/linux/compiler.h b/include/linux/compiler.h index f504edebd5d7..1729bd17e9b7 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -326,9 +326,9 @@ unsigned long read_word_at_a_time(const void *addr) #define data_race(expr) \ ({ \ typeof(({ expr; })) __val; \ - kcsan_nestable_atomic_begin(); \ + kcsan_disable_current(); \ __val = ({ expr; }); \ - kcsan_nestable_atomic_end(); \ + kcsan_enable_current(); \ __val; \ }) #else |