* [PATCH] nptl: Do not set signal mask on second setjmp return [BZ #28607]
@ 2021-11-18 20:03 Florian Weimer via Libc-alpha
2021-11-22 19:24 ` Adhemerval Zanella via Libc-alpha
0 siblings, 1 reply; 2+ messages in thread
From: Florian Weimer via Libc-alpha @ 2021-11-18 20:03 UTC (permalink / raw)
To: libc-alpha; +Cc: Gibeom Gwon
__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.
Tested on i686-linux-gnu and x86_64-linux-gnu.
---
nptl/pthread_create.c | 4 +--
sysdeps/pthread/Makefile | 1 +
sysdeps/pthread/tst-pthread-exit-signal.c | 45 +++++++++++++++++++++++++++++++
3 files changed, 48 insertions(+), 2 deletions(-)
diff --git a/nptl/pthread_create.c b/nptl/pthread_create.c
index d6ea43a754..bad9eeb52f 100644
--- a/nptl/pthread_create.c
+++ b/nptl/pthread_create.c
@@ -406,8 +406,6 @@ 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);
@@ -417,6 +415,8 @@ 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 df8943f486..c657101696 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 0000000000..b4526fe663
--- /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>
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] nptl: Do not set signal mask on second setjmp return [BZ #28607]
2021-11-18 20:03 [PATCH] nptl: Do not set signal mask on second setjmp return [BZ #28607] Florian Weimer via Libc-alpha
@ 2021-11-22 19:24 ` Adhemerval Zanella via Libc-alpha
0 siblings, 0 replies; 2+ messages in thread
From: Adhemerval Zanella via Libc-alpha @ 2021-11-22 19:24 UTC (permalink / raw)
To: Florian Weimer, libc-alpha; +Cc: Gibeom Gwon
On 18/11/2021 17:03, Florian Weimer via Libc-alpha wrote:
> __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.
>
> Tested on i686-linux-gnu and x86_64-linux-gnu.,
LGTM, thanks.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
>
> ---
> nptl/pthread_create.c | 4 +--
> sysdeps/pthread/Makefile | 1 +
> sysdeps/pthread/tst-pthread-exit-signal.c | 45 +++++++++++++++++++++++++++++++
> 3 files changed, 48 insertions(+), 2 deletions(-)
>
> diff --git a/nptl/pthread_create.c b/nptl/pthread_create.c
> index d6ea43a754..bad9eeb52f 100644
> --- a/nptl/pthread_create.c
> +++ b/nptl/pthread_create.c
> @@ -406,8 +406,6 @@ 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);
> @@ -417,6 +415,8 @@ 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. */
Ok.
> diff --git a/sysdeps/pthread/Makefile b/sysdeps/pthread/Makefile
> index df8943f486..c657101696 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 \
Ok.
> diff --git a/sysdeps/pthread/tst-pthread-exit-signal.c b/sysdeps/pthread/tst-pthread-exit-signal.c
> new file mode 100644
> index 0000000000..b4526fe663
> --- /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>
>
Ok.
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2021-11-22 19:24 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-11-18 20:03 [PATCH] nptl: Do not set signal mask on second setjmp return [BZ #28607] Florian Weimer via Libc-alpha
2021-11-22 19:24 ` Adhemerval Zanella via Libc-alpha
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).