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| author | James Morse <james.morse@arm.com> | 2016-04-28 16:18:52 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-04-28 19:34:04 -0700 |
| commit | bdab42dfc974d15303afbf259f340f374a453974 (patch) | |
| tree | 92cfc8967934a0ff318d176351599a20bcb1004f /kernel/kcov.c | |
| parent | fd901c95388b3bd5a6f749ed1d677a672b992298 (diff) | |
| download | lwn-bdab42dfc974d15303afbf259f340f374a453974.tar.gz lwn-bdab42dfc974d15303afbf259f340f374a453974.zip | |
kcov: don't trace the code coverage code
Kcov causes the compiler to add a call to __sanitizer_cov_trace_pc() in
every basic block. Ftrace patches in a call to _mcount() to each
function it has annotated.
Letting these mechanisms annotate each other is a bad thing. Break the
loop by adding 'notrace' to __sanitizer_cov_trace_pc() so that ftrace
won't try to patch this code.
This patch lets arm64 with KCOV and STACK_TRACER boot.
Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/kcov.c')
| -rw-r--r-- | kernel/kcov.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/kcov.c b/kernel/kcov.c index 3efbee0834a8..78bed7125515 100644 --- a/kernel/kcov.c +++ b/kernel/kcov.c @@ -43,7 +43,7 @@ struct kcov { * Entry point from instrumented code. * This is called once per basic-block/edge. */ -void __sanitizer_cov_trace_pc(void) +void notrace __sanitizer_cov_trace_pc(void) { struct task_struct *t; enum kcov_mode mode; |