[PATCH v2 2/5] nptl: Add __raise_nocancel
Adhemerval Zanella
adhemerval.zanella@linaro.org
Tue Sep 2 19:26:54 GMT 2025
The function sends a signal to current thread using raw syscalls.
---
include/signal.h | 2 ++
nptl/pthread_kill.c | 21 ++++++----------
signal/Makefile | 2 +-
signal/raise_nostatus.c | 27 +++++++++++++++++++++
sysdeps/posix/raise.c | 2 +-
sysdeps/unix/sysv/linux/raise_nostatus.c | 31 ++++++++++++++++++++++++
6 files changed, 69 insertions(+), 16 deletions(-)
create mode 100644 signal/raise_nostatus.c
create mode 100644 sysdeps/unix/sysv/linux/raise_nostatus.c
diff --git a/include/signal.h b/include/signal.h
index 73f18dddd7..9aa4c0e055 100644
--- a/include/signal.h
+++ b/include/signal.h
@@ -65,6 +65,8 @@ extern int __xpg_sigpause (int sig);
/* Allocate real-time signal with highest/lowest available priority. */
extern int __libc_allocate_rtsig (int __high);
+extern int __raise_nostatus (int signo) attribute_hidden;
+
# if IS_IN (rtld)
extern __typeof (__sigaction) __sigaction attribute_hidden;
extern __typeof (__libc_sigaction) __libc_sigaction attribute_hidden;
diff --git a/nptl/pthread_kill.c b/nptl/pthread_kill.c
index 3938e3f8cd..6529887ff5 100644
--- a/nptl/pthread_kill.c
+++ b/nptl/pthread_kill.c
@@ -29,20 +29,13 @@ __pthread_kill_implementation (pthread_t threadid, int signo, int no_tid)
{
struct pthread *pd = (struct pthread *) threadid;
if (pd == THREAD_SELF)
- {
- /* Use the actual TID from the kernel, so that it refers to the
- current thread even if called after vfork. There is no
- signal blocking in this case, so that the signal is delivered
- immediately, before __pthread_kill_internal returns: a signal
- sent to the thread itself needs to be delivered
- synchronously. (It is unclear if Linux guarantees the
- delivery of all pending signals after unblocking in the code
- below. POSIX only guarantees delivery of a single signal,
- which may not be the right one.) */
- pid_t tid = INTERNAL_SYSCALL_CALL (gettid);
- int ret = INTERNAL_SYSCALL_CALL (tgkill, __getpid (), tid, signo);
- return INTERNAL_SYSCALL_ERROR_P (ret) ? INTERNAL_SYSCALL_ERRNO (ret) : 0;
- }
+ /* There is no signal blocking in this case, so that the signal is
+ delivered immediately, before __pthread_kill_internal returns: a signal
+ sent to the thread itself needs to be delivered synchronously. (It is
+ unclear if Linux guarantees the delivery of all pending signals after
+ unblocking in the code below. POSIX only guarantees delivery of a
+ single signal, which may not be the right one.) */
+ return __raise_nostatus (signo);
/* Block all signals, as required by pd->exit_lock. */
internal_sigset_t old_mask;
diff --git a/signal/Makefile b/signal/Makefile
index 8c7961c5f0..468a8b93f0 100644
--- a/signal/Makefile
+++ b/signal/Makefile
@@ -34,7 +34,7 @@ headers := signal.h sys/signal.h \
bits/types/__sigval_t.h bits/signal_ext.h \
bits/sigstksz.h
-routines := signal raise killpg \
+routines := signal raise raise_nostatus killpg \
sigaction libc_sigaction sigprocmask kill \
sigpending sigsuspend sigwait \
sigblock sigsetmask sigpause sigvec \
diff --git a/signal/raise_nostatus.c b/signal/raise_nostatus.c
new file mode 100644
index 0000000000..ed572ddee2
--- /dev/null
+++ b/signal/raise_nostatus.c
@@ -0,0 +1,27 @@
+/* Internal function to send a signal to itself. Generic version.
+ Copyright (C) 2025 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/>. */
+
+#include <sysdep.h>
+#include <pthread.h>
+#include <unistd.h>
+
+int
+__raise_nostatus (int signo)
+{
+ return __kill (__getpid (), signo);
+}
diff --git a/sysdeps/posix/raise.c b/sysdeps/posix/raise.c
index da3f11ccf2..3c5f032c5c 100644
--- a/sysdeps/posix/raise.c
+++ b/sysdeps/posix/raise.c
@@ -23,7 +23,7 @@
int
raise (int sig)
{
- int ret = __pthread_kill (__pthread_self (), sig);
+ int ret = __raise_nostatus (sig);
if (ret != 0)
{
__set_errno (ret);
diff --git a/sysdeps/unix/sysv/linux/raise_nostatus.c b/sysdeps/unix/sysv/linux/raise_nostatus.c
new file mode 100644
index 0000000000..6f9ebc1ac9
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/raise_nostatus.c
@@ -0,0 +1,31 @@
+/* Internal function to send a signal to itself. Linux version.
+ Copyright (C) 2025 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/>. */
+
+#include <sysdep.h>
+#include <pthread.h>
+#include <unistd.h>
+
+int
+__raise_nostatus (int signo)
+{
+ /* Use direct syscall to avoid external symbols. */
+ pid_t tid = INTERNAL_SYSCALL_CALL (gettid);
+ pid_t pid = INTERNAL_SYSCALL_CALL (getpid);
+ int ret = INTERNAL_SYSCALL_CALL (tgkill, pid, tid, signo);
+ return INTERNAL_SYSCALL_ERROR_P (ret) ? INTERNAL_SYSCALL_ERRNO (ret) : 0;
+}
--
2.43.0
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