Add a SIGTRAP stress test that exercises repeatedly enabling/disabling an event while it concurrently keeps firing.

Link: https://lore.kernel.org/all/Y0E3uG7jOywn7vy3@elver.google.com/ Signed-off-by: Marco Elver elver@google.com --- .../selftests/perf_events/sigtrap_threads.c | 35 +++++++++++++++++-- 1 file changed, 32 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/perf_events/sigtrap_threads.c b/tools/testing/selftests/perf_events/sigtrap_threads.c index 6d849dc2bee0..d1d8483ac628 100644 --- a/tools/testing/selftests/perf_events/sigtrap_threads.c +++ b/tools/testing/selftests/perf_events/sigtrap_threads.c @@ -62,6 +62,8 @@ static struct perf_event_attr make_event_attr(bool enabled, volatile void *addr, .remove_on_exec = 1, /* Required by sigtrap. */ .sigtrap = 1, /* Request synchronous SIGTRAP on event. */ .sig_data = TEST_SIG_DATA(addr, id), + .exclude_kernel = 1, /* To allow */ + .exclude_hv = 1, /* running as !root */ }; return attr; } @@ -93,9 +95,13 @@ static void *test_thread(void *arg)

__atomic_fetch_add(&ctx.tids_want_signal, tid, __ATOMIC_RELAXED); iter = ctx.iterate_on; /* read */ - for (i = 0; i < iter - 1; i++) { - __atomic_fetch_add(&ctx.tids_want_signal, tid, __ATOMIC_RELAXED); - ctx.iterate_on = iter; /* idempotent write */ + if (iter >= 0) { + for (i = 0; i < iter - 1; i++) { + __atomic_fetch_add(&ctx.tids_want_signal, tid, __ATOMIC_RELAXED); + ctx.iterate_on = iter; /* idempotent write */ + } + } else { + while (ctx.iterate_on); }

return NULL; @@ -208,4 +214,27 @@ TEST_F(sigtrap_threads, signal_stress) EXPECT_EQ(ctx.first_siginfo.si_perf_data, TEST_SIG_DATA(&ctx.iterate_on, 0)); }

+TEST_F(sigtrap_threads, signal_stress_with_disable) +{ + const int target_count = NUM_THREADS * 3000; + int i; + + ctx.iterate_on = -1; + + EXPECT_EQ(ioctl(self->fd, PERF_EVENT_IOC_ENABLE, 0), 0); + pthread_barrier_wait(&self->barrier); + while (__atomic_load_n(&ctx.signal_count, __ATOMIC_RELAXED) < target_count) { + EXPECT_EQ(ioctl(self->fd, PERF_EVENT_IOC_DISABLE, 0), 0); + EXPECT_EQ(ioctl(self->fd, PERF_EVENT_IOC_ENABLE, 0), 0); + } + ctx.iterate_on = 0; + for (i = 0; i < NUM_THREADS; i++) + ASSERT_EQ(pthread_join(self->threads[i], NULL), 0); + EXPECT_EQ(ioctl(self->fd, PERF_EVENT_IOC_DISABLE, 0), 0); + + EXPECT_EQ(ctx.first_siginfo.si_addr, &ctx.iterate_on); + EXPECT_EQ(ctx.first_siginfo.si_perf_type, PERF_TYPE_BREAKPOINT); + EXPECT_EQ(ctx.first_siginfo.si_perf_data, TEST_SIG_DATA(&ctx.iterate_on, 0)); +} + TEST_HARNESS_MAIN