From e747d0456adc080a1d31fb653bda9dc491795c80 Mon Sep 17 00:00:00 2001 From: Jan Stancek Date: Sun, 16 Jun 2019 11:14:16 +0200 Subject: [PATCH] syscalls/tgkill03: wait for defunct tid to get detached Case where defunct tid is used has been observed to sporadically fail: tgkill03.c:96: FAIL: Defunct tid should have failed with ESRCH: SUCCESS glibc __pthread_timedjoin_ex() waits for CLONE_CHILD_CLEARTID to clear tid, and then resumes. Kernel clears it (glibc pd->tid) at: do_exit exit_mm mm_release put_user(0, tsk->clear_child_tid); but kernel tid is still valid, presumably until: release_task __exit_signal __unhash_process detach_pid To avoid race wait until /proc//task/ disappears. Signed-off-by: Jan Stancek Reviewed-by: Li Wang Acked-by: Sumit Garg Upstream-Status: Backport [https://github.com/linux-test-project/ltp/commit/e747d0456adc080a1d31fb653bda9dc491795c80] Signed-off-by: He Zhe --- testcases/kernel/syscalls/tgkill/tgkill03.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/testcases/kernel/syscalls/tgkill/tgkill03.c b/testcases/kernel/syscalls/tgkill/tgkill03.c index f5bbdc5..593a217 100644 --- a/testcases/kernel/syscalls/tgkill/tgkill03.c +++ b/testcases/kernel/syscalls/tgkill/tgkill03.c @@ -7,6 +7,7 @@ #include #include +#include #include #include "tst_safe_pthread.h" @@ -42,6 +43,7 @@ static void setup(void) { sigset_t sigusr1; pthread_t defunct_thread; + char defunct_tid_path[PATH_MAX]; sigemptyset(&sigusr1); sigaddset(&sigusr1, SIGUSR1); @@ -55,8 +57,9 @@ static void setup(void) TST_CHECKPOINT_WAIT(0); SAFE_PTHREAD_CREATE(&defunct_thread, NULL, defunct_thread_func, NULL); - SAFE_PTHREAD_JOIN(defunct_thread, NULL); + sprintf(defunct_tid_path, "/proc/%d/task/%d", getpid(), defunct_tid); + TST_RETRY_FN_EXP_BACKOFF(access(defunct_tid_path, R_OK), -1, 15); } static void cleanup(void) @@ -108,4 +111,5 @@ static struct tst_test test = { .setup = setup, .cleanup = cleanup, .test = run, + .timeout = 20, }; -- 2.7.4