locking/atomic: Correct (cmp)xchg() instrumentation

All xchg() and cmpxchg() ops are atomic RMWs, but currently we
instrument these with instrument_atomic_write() rather than
instrument_atomic_read_write(), missing the read aspect.

Similarly, all try_cmpxchg() ops are non-atomic RMWs on *oldp, but we
instrument these accesses with instrument_atomic_write() rather than
instrument_read_write(), missing the read aspect and erroneously marking
these as atomic.

Fix the instrumentation for both points.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20230413160644.490976-1-mark.rutland@arm.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Mark Rutland
2023-04-13 17:06:44 +01:00
committed by Ingo Molnar
parent 5cd4c26841
commit ec570320b0
2 changed files with 41 additions and 41 deletions

View File

@@ -104,8 +104,8 @@ cat <<EOF
EOF
[ -n "$kcsan_barrier" ] && printf "\t${kcsan_barrier}; \\\\\n"
cat <<EOF
instrument_atomic_write(__ai_ptr, ${mult}sizeof(*__ai_ptr)); \\
instrument_atomic_write(__ai_oldp, ${mult}sizeof(*__ai_oldp)); \\
instrument_atomic_read_write(__ai_ptr, ${mult}sizeof(*__ai_ptr)); \\
instrument_read_write(__ai_oldp, ${mult}sizeof(*__ai_oldp)); \\
arch_${xchg}${order}(__ai_ptr, __ai_oldp, __VA_ARGS__); \\
})
EOF
@@ -119,7 +119,7 @@ cat <<EOF
EOF
[ -n "$kcsan_barrier" ] && printf "\t${kcsan_barrier}; \\\\\n"
cat <<EOF
instrument_atomic_write(__ai_ptr, ${mult}sizeof(*__ai_ptr)); \\
instrument_atomic_read_write(__ai_ptr, ${mult}sizeof(*__ai_ptr)); \\
arch_${xchg}${order}(__ai_ptr, __VA_ARGS__); \\
})
EOF