1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
|
From e747d0456adc080a1d31fb653bda9dc491795c80 Mon Sep 17 00:00:00 2001
From: Jan Stancek <jstancek@redhat.com>
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/<pid>/task/<tid> disappears.
Signed-off-by: Jan Stancek <jstancek@redhat.com>
Reviewed-by: Li Wang <liwang@redhat.com>
Acked-by: Sumit Garg <sumit.garg@linaro.org>
Upstream-Status: Backport
[https://github.com/linux-test-project/ltp/commit/e747d0456adc080a1d31fb653bda9dc491795c80]
Signed-off-by: He Zhe <zhe.he@windriver.com>
---
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 <pthread.h>
#include <pwd.h>
+#include <stdio.h>
#include <sys/types.h>
#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
|
