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| author | Christian Brauner <brauner@kernel.org> | 2026-06-04 11:25:14 +0300 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2026-06-04 11:25:14 +0300 |
| commit | b466bfe0ec0ff80994b0fa3ffe7bc36f0ce6be4b (patch) | |
| tree | 1e65bf935c10395b928dfccc132c604f5413ee91 /tools | |
| parent | 70a03a385de2b8f0fa54dbc70bdc3ed176853d1c (diff) | |
| parent | 0c4aefe3c2d0f272a2ad73699a12d4446ffdbe7b (diff) | |
| download | linux-b466bfe0ec0ff80994b0fa3ffe7bc36f0ce6be4b.tar.xz | |
Merge patch series "eventpoll: Fix epoll_wait() report false negative"
Nam Cao <namcao@linutronix.de> says:
While staring at epoll, I noticed ep_events_available() looks wrong. I
wrote a small program to confirm, and yes it is definitely wrong.
This series adds a reproducer to kselftest, and fix the bug.
* patches from https://patch.msgid.link/cover.1780422137.git.namcao@linutronix.de:
eventpoll: Fix epoll_wait() report false negative
selftests/eventpoll: Add test for multiple waiters
Link: https://patch.msgid.link/cover.1780422137.git.namcao@linutronix.de
Signed-off-by: Christian Brauner <brauner@kernel.org>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/testing/selftests/filesystems/epoll/epoll_wakeup_test.c | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/tools/testing/selftests/filesystems/epoll/epoll_wakeup_test.c b/tools/testing/selftests/filesystems/epoll/epoll_wakeup_test.c index 8bc57a2ef966..f6f1a7ff01b0 100644 --- a/tools/testing/selftests/filesystems/epoll/epoll_wakeup_test.c +++ b/tools/testing/selftests/filesystems/epoll/epoll_wakeup_test.c @@ -3493,4 +3493,49 @@ TEST(epoll64) close(ctx.sfd[1]); } +static void *epoll65_wait(void *ctx_) +{ + struct epoll_mtcontext *ctx = ctx_; + struct epoll_event event; + + for (int i = 0; i < 100000; ++i) { + if (!epoll_wait(ctx->efd[0], &event, 1, 0)) + return (void *)ENODATA; + } + + return (void *)0; +} + +TEST(epoll65) +{ + struct epoll_mtcontext ctx; + struct epoll_event event; + int64_t dummy_data = 99; + pthread_t threads[64]; + uintptr_t ret; + int i, err; + + ctx.efd[0] = epoll_create(1); + ASSERT_GE(ctx.efd[0], 0); + ctx.efd[1] = eventfd(0, 0); + ASSERT_GE(ctx.efd[1], 0); + + event.events = EPOLLIN; + err = epoll_ctl(ctx.efd[0], EPOLL_CTL_ADD, ctx.efd[1], &event); + ASSERT_EQ(err, 0); + + write(ctx.efd[1], &dummy_data, sizeof(dummy_data)); + + for (i = 0; i < ARRAY_SIZE(threads); ++i) + ASSERT_EQ(pthread_create(&threads[i], NULL, epoll65_wait, &ctx), 0); + + for (i = 0; i < ARRAY_SIZE(threads); ++i) { + ASSERT_EQ(pthread_join(threads[i], (void **)&ret), 0); + ASSERT_EQ(ret, 0); + } + + close(ctx.efd[0]); + close(ctx.efd[1]); +} + TEST_HARNESS_MAIN |