Now that pthread_kill is provided by libc.so it is possible to
implement the generic POSIX implementation as
'pthread_kill(pthread_self(), sig)'.
For Linux implementation, pthread_kill read the targeting TID from
the TCB. For raise, this it not possible because it would make raise
fail when issue after vfork (where creates the resulting process
has a different TID from the parent, but its TCB is not updated as
for pthread_create). To make raise use pthread_kill, it is make
usable from vfork by getting the target thread id through gettid
syscall.
Checked on x86_64-linux-gnu and aarch64-linux-gnu.
---
include/pthread.h | 5 ++++
nptl/pthreadP.h | 4 ++-
nptl/pthread_kill.c | 40 ++++++++++++++++---------
nptl/pthread_self.c | 4 ++-
sysdeps/htl/pthreadP.h | 2 --
sysdeps/posix/raise.c | 11 +++++--
sysdeps/unix/sysv/linux/raise.c | 52 ---------------------------------
7 files changed, 47 insertions(+), 71 deletions(-)
delete mode 100644 sysdeps/unix/sysv/linux/raise.c
@@ -16,4 +16,9 @@ extern int __pthread_barrier_wait (pthread_barrier_t *__barrier)
/* This function is called to initialize the pthread library. */
extern void __pthread_initialize (void) __attribute__ ((weak));
+
+extern int __pthread_kill (pthread_t threadid, int signo);
+
+extern pthread_t __pthread_self (void);
+
#endif
@@ -508,11 +508,13 @@ extern int __pthread_once (pthread_once_t *once_control,
libc_hidden_proto (__pthread_once)
extern int __pthread_atfork (void (*prepare) (void), void (*parent) (void),
void (*child) (void));
-extern pthread_t __pthread_self (void);
+libc_hidden_proto (__pthread_self)
extern int __pthread_equal (pthread_t thread1, pthread_t thread2);
extern int __pthread_detach (pthread_t th);
libc_hidden_proto (__pthread_detach)
extern int __pthread_kill (pthread_t threadid, int signo);
+libc_hidden_proto (__pthread_kill)
+extern int __pthread_cancel (pthread_t th);
extern void __pthread_exit (void *value) __attribute__ ((__noreturn__));
libc_hidden_proto (__pthread_exit)
extern int __pthread_join (pthread_t threadid, void **thread_return);
@@ -28,24 +28,38 @@ __pthread_kill (pthread_t threadid, int signo)
if (__is_internal_signal (signo))
return EINVAL;
- /* Force load of pd->tid into local variable or register. Otherwise
- if a thread exits between ESRCH test and tgkill, we might return
- EINVAL, because pd->tid would be cleared by the kernel. */
+ pid_t tid;
struct pthread *pd = (struct pthread *) threadid;
- pid_t tid = atomic_forced_read (pd->tid);
- if (__glibc_unlikely (tid <= 0))
- /* Not a valid thread handle. */
- return ESRCH;
- /* We have a special syscall to do the work. */
- pid_t pid = __getpid ();
+ if (pd == THREAD_SELF)
+ tid = INLINE_SYSCALL_CALL (gettid);
+ else
+ /* Force load of pd->tid into local variable or register. Otherwise
+ if a thread exits between ESRCH test and tgkill, we might return
+ EINVAL, because pd->tid would be cleared by the kernel. */
+ tid = atomic_forced_read (pd->tid);
- int val = INTERNAL_SYSCALL_CALL (tgkill, pid, tid, signo);
- return (INTERNAL_SYSCALL_ERROR_P (val)
- ? INTERNAL_SYSCALL_ERRNO (val) : 0);
+ int val;
+ if (__glibc_likely (tid > 0))
+ {
+ pid_t pid = __getpid ();
+
+ val = INTERNAL_SYSCALL_CALL (tgkill, pid, tid, signo);
+ val = (INTERNAL_SYSCALL_ERROR_P (val)
+ ? INTERNAL_SYSCALL_ERRNO (val) : 0);
+ }
+ else
+ val = ESRCH;
+
+ return val;
}
+/* Some architectures (for instance arm) might pull raise through libgcc, so
+ avoid the symbol version if it ends up being used on ld.so. */
+#if !IS_IN(rtld)
+libc_hidden_def (__pthread_kill)
versioned_symbol (libc, __pthread_kill, pthread_kill, GLIBC_2_34);
-#if OTHER_SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_34)
+# if OTHER_SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_34)
compat_symbol (libc, __pthread_kill, pthread_kill, GLIBC_2_0);
+# endif
#endif
@@ -20,7 +20,9 @@
#include <tls.h>
pthread_t
-pthread_self (void)
+__pthread_self (void)
{
return (pthread_t) THREAD_SELF;
}
+libc_hidden_def (__pthread_self)
+weak_alias (__pthread_self, pthread_self)
@@ -31,8 +31,6 @@ extern void __pthread_init_static_tls (struct link_map *) attribute_hidden;
/* These represent the interface used by glibc itself. */
-extern pthread_t __pthread_self (void);
-extern int __pthread_kill (pthread_t threadid, int signo);
extern struct __pthread **__pthread_threads;
extern int __pthread_mutex_init (pthread_mutex_t *__mutex, const pthread_mutexattr_t *__attr);
@@ -16,13 +16,20 @@
<https://www.gnu.org/licenses/>. */
#include <signal.h>
-#include <unistd.h>
+#include <errno.h>
+#include <pthread.h>
/* Raise the signal SIG. */
int
raise (int sig)
{
- return __kill (__getpid (), sig);
+ int ret = __pthread_kill (__pthread_self (), sig);
+ if (ret != 0)
+ {
+ __set_errno (ret);
+ ret = -1;
+ }
+ return ret;
}
libc_hidden_def (raise)
weak_alias (raise, gsignal)
deleted file mode 100644
@@ -1,52 +0,0 @@
-/* Copyright (C) 2002-2021 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
- Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
-
- 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 <signal.h>
-#include <sysdep.h>
-#include <errno.h>
-#include <sys/types.h>
-#include <unistd.h>
-#include <internal-signals.h>
-
-int
-raise (int sig)
-{
- /* rt_sigprocmask may fail if:
-
- 1. sigsetsize != sizeof (sigset_t) (EINVAL)
- 2. a failure in copy from/to user space (EFAULT)
- 3. an invalid 'how' operation (EINVAL)
-
- The first case is already handle in glibc syscall call by using the arch
- defined _NSIG. Second case is handled by using a stack allocated mask.
- The last one should be handled by the block/unblock functions. */
-
- sigset_t set;
- __libc_signal_block_app (&set);
-
- pid_t pid = INTERNAL_SYSCALL_CALL (getpid);
- pid_t tid = INTERNAL_SYSCALL_CALL (gettid);
-
- int ret = INLINE_SYSCALL_CALL (tgkill, pid, tid, sig);
-
- __libc_signal_restore_set (&set);
-
- return ret;
-}
-libc_hidden_def (raise)
-weak_alias (raise, gsignal)