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
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
|
From bfe68fe3c475fe34bed4e017d6e63196c305c934 Mon Sep 17 00:00:00 2001
From: Florian Weimer <fweimer@redhat.com>
Date: Wed, 24 Nov 2021 08:59:54 +0100
Subject: [PATCH] nptl: Do not set signal mask on second setjmp return [BZ
#28607]
__libc_signal_restore_set was in the wrong place: It also ran
when setjmp returned the second time (after pthread_exit or
pthread_cancel). This is observable with blocked pending
signals during thread exit.
Fixes commit b3cae39dcbfa2432b3f3aa28854d8ac57f0de1b8
("nptl: Start new threads with all signals blocked [BZ #25098]").
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
(cherry picked from commit e186fc5a31e46f2cbf5ea1a75223b4412907f3d8)
---
nptl/pthread_create.c | 4 +--
sysdeps/pthread/Makefile | 1 +
sysdeps/pthread/tst-pthread-exit-signal.c | 45 +++++++++++++++++++++++++++++++
3 files changed, 48 insertions(+), 2 deletions(-)
create mode 100644 sysdeps/pthread/tst-pthread-exit-signal.c
diff --git a/nptl/pthread_create.c b/nptl/pthread_create.c
index bc213f0..3db0c9f 100644
--- a/nptl/pthread_create.c
+++ b/nptl/pthread_create.c
@@ -407,8 +407,6 @@ start_thread (void *arg)
unwind_buf.priv.data.prev = NULL;
unwind_buf.priv.data.cleanup = NULL;
- __libc_signal_restore_set (&pd->sigmask);
-
/* Allow setxid from now onwards. */
if (__glibc_unlikely (atomic_exchange_acq (&pd->setxid_futex, 0) == -2))
futex_wake (&pd->setxid_futex, 1, FUTEX_PRIVATE);
@@ -418,6 +416,8 @@ start_thread (void *arg)
/* Store the new cleanup handler info. */
THREAD_SETMEM (pd, cleanup_jmp_buf, &unwind_buf);
+ __libc_signal_restore_set (&pd->sigmask);
+
LIBC_PROBE (pthread_start, 3, (pthread_t) pd, pd->start_routine, pd->arg);
/* Run the code the user provided. */
diff --git a/sysdeps/pthread/Makefile b/sysdeps/pthread/Makefile
index df8943f..c657101 100644
--- a/sysdeps/pthread/Makefile
+++ b/sysdeps/pthread/Makefile
@@ -118,6 +118,7 @@ tests += tst-cnd-basic tst-mtx-trylock tst-cnd-broadcast \
tst-unload \
tst-unwind-thread \
tst-pt-vfork1 tst-pt-vfork2 tst-vfork1x tst-vfork2x \
+ tst-pthread-exit-signal \
tst-pthread-setuid-loop \
tst-pthread_cancel-exited \
tst-pthread_cancel-select-loop \
diff --git a/sysdeps/pthread/tst-pthread-exit-signal.c b/sysdeps/pthread/tst-pthread-exit-signal.c
new file mode 100644
index 0000000..b4526fe
--- /dev/null
+++ b/sysdeps/pthread/tst-pthread-exit-signal.c
@@ -0,0 +1,45 @@
+/* Test that pending signals are not delivered on thread exit (bug 28607).
+ Copyright (C) 2021 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+/* Due to bug 28607, pthread_kill (or pthread_cancel) restored the
+ signal mask during during thread exit, triggering the delivery of a
+ blocked pending signal (SIGUSR1 in this test). */
+
+#include <support/xthread.h>
+#include <support/xsignal.h>
+
+static void *
+threadfunc (void *closure)
+{
+ sigset_t sigmask;
+ sigfillset (&sigmask);
+ xpthread_sigmask (SIG_SETMASK, &sigmask, NULL);
+ xpthread_kill (pthread_self (), SIGUSR1);
+ pthread_exit (NULL);
+ return NULL;
+}
+
+static int
+do_test (void)
+{
+ pthread_t thr = xpthread_create (NULL, threadfunc, NULL);
+ xpthread_join (thr);
+ return 0;
+}
+
+#include <support/test-driver.c>
--
1.8.3.1
|
