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- /* Linuxthreads - a simple clone()-based implementation of Posix */
- /* threads for Linux. */
- /* Copyright (C) 1996 Xavier Leroy (Xavier.Leroy@inria.fr) */
- /* */
- /* This program is free software; you can redistribute it and/or */
- /* modify it under the terms of the GNU Library General Public License */
- /* as published by the Free Software Foundation; either version 2 */
- /* of the License, or (at your option) any later version. */
- /* */
- /* This program 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 Library General Public License for more details. */
- /* Handling of signals */
- #include <errno.h>
- #include <signal.h>
- #include <stdio.h>
- #include <sys/syscall.h>
- #include "pthread.h"
- #include "internals.h"
- #include "spinlock.h"
- #include <bits/sigcontextinfo.h>
- int pthread_sigmask(int how, const sigset_t * newmask, sigset_t * oldmask)
- {
- sigset_t mask;
- if (newmask != NULL) {
- mask = *newmask;
- /* Don't allow __pthread_sig_restart to be unmasked.
- Don't allow __pthread_sig_cancel to be masked. */
- switch(how) {
- case SIG_SETMASK:
- sigaddset(&mask, __pthread_sig_restart);
- sigdelset(&mask, __pthread_sig_cancel);
- if (__pthread_sig_debug > 0)
- sigdelset(&mask, __pthread_sig_debug);
- break;
- case SIG_BLOCK:
- sigdelset(&mask, __pthread_sig_cancel);
- if (__pthread_sig_debug > 0)
- sigdelset(&mask, __pthread_sig_debug);
- break;
- case SIG_UNBLOCK:
- sigdelset(&mask, __pthread_sig_restart);
- break;
- }
- newmask = &mask;
- }
- if (sigprocmask(how, newmask, oldmask) == -1)
- return errno;
- else
- return 0;
- }
- int pthread_kill(pthread_t thread, int signo)
- {
- pthread_handle handle = thread_handle(thread);
- int pid;
- __pthread_lock(&handle->h_lock, NULL);
- if (invalid_handle(handle, thread)) {
- __pthread_unlock(&handle->h_lock);
- return ESRCH;
- }
- pid = handle->h_descr->p_pid;
- __pthread_unlock(&handle->h_lock);
- if (kill(pid, signo) == -1)
- return errno;
- else
- return 0;
- }
- /* User-provided signal handlers */
- typedef void (*arch_sighandler_t) __PMT ((int, SIGCONTEXT));
- static union
- {
- arch_sighandler_t old;
- void (*rt) (int, struct siginfo *, struct ucontext *);
- } sighandler[NSIG];
- /* The wrapper around user-provided signal handlers */
- static void pthread_sighandler(int signo, SIGCONTEXT ctx)
- {
- pthread_descr self = thread_self();
- char * in_sighandler;
- /* If we're in a sigwait operation, just record the signal received
- and return without calling the user's handler */
- if (THREAD_GETMEM(self, p_sigwaiting)) {
- THREAD_SETMEM(self, p_sigwaiting, 0);
- THREAD_SETMEM(self, p_signal, signo);
- return;
- }
- /* Record that we're in a signal handler and call the user's
- handler function */
- in_sighandler = THREAD_GETMEM(self, p_in_sighandler);
- if (in_sighandler == NULL)
- THREAD_SETMEM(self, p_in_sighandler, CURRENT_STACK_FRAME);
- sighandler[signo].old(signo, SIGCONTEXT_EXTRA_ARGS ctx);
- if (in_sighandler == NULL)
- THREAD_SETMEM(self, p_in_sighandler, NULL);
- }
- /* The same, this time for real-time signals. */
- static void pthread_sighandler_rt(int signo, struct siginfo *si,
- struct ucontext *uc)
- {
- pthread_descr self = thread_self();
- char * in_sighandler;
- /* If we're in a sigwait operation, just record the signal received
- and return without calling the user's handler */
- if (THREAD_GETMEM(self, p_sigwaiting)) {
- THREAD_SETMEM(self, p_sigwaiting, 0);
- THREAD_SETMEM(self, p_signal, signo);
- return;
- }
- /* Record that we're in a signal handler and call the user's
- handler function */
- in_sighandler = THREAD_GETMEM(self, p_in_sighandler);
- if (in_sighandler == NULL)
- THREAD_SETMEM(self, p_in_sighandler, CURRENT_STACK_FRAME);
- sighandler[signo].rt(signo, si, uc);
- if (in_sighandler == NULL)
- THREAD_SETMEM(self, p_in_sighandler, NULL);
- }
- /* The wrapper around sigaction. Install our own signal handler
- around the signal. */
- libpthread_hidden_proto(sigaction)
- int sigaction(int sig, const struct sigaction * act,
- struct sigaction * oact)
- {
- struct sigaction newact;
- struct sigaction *newactp;
- #ifdef DEBUG_PT
- printf(__FUNCTION__": pthreads wrapper!\n");
- #endif
- if (sig == __pthread_sig_restart ||
- sig == __pthread_sig_cancel ||
- (sig == __pthread_sig_debug && __pthread_sig_debug > 0))
- return EINVAL;
- if (act)
- {
- newact = *act;
- if (act->sa_handler != SIG_IGN && act->sa_handler != SIG_DFL
- && sig > 0 && sig < NSIG)
- {
- if (act->sa_flags & SA_SIGINFO)
- newact.sa_handler = (__sighandler_t) pthread_sighandler_rt;
- else
- newact.sa_handler = (__sighandler_t) pthread_sighandler;
- }
- newactp = &newact;
- }
- else
- newactp = NULL;
- if (__libc_sigaction(sig, newactp, oact) == -1)
- return -1;
- #ifdef DEBUG_PT
- printf(__FUNCTION__": sighandler installed, sigaction successful\n");
- #endif
- if (sig > 0 && sig < NSIG)
- {
- if (oact != NULL)
- oact->sa_handler = (__sighandler_t) sighandler[sig].old;
- if (act)
- /* For the assignment is does not matter whether it's a normal
- or real-time signal. */
- sighandler[sig].old = (arch_sighandler_t) act->sa_handler;
- }
- return 0;
- }
- libpthread_hidden_def(sigaction)
- /* A signal handler that does nothing */
- static void pthread_null_sighandler(int sig attribute_unused) { }
- /* sigwait -- synchronously wait for a signal */
- int sigwait(const sigset_t * set, int * sig)
- {
- volatile pthread_descr self = thread_self();
- sigset_t mask;
- int s;
- sigjmp_buf jmpbuf;
- struct sigaction sa;
- /* Get ready to block all signals except those in set
- and the cancellation signal.
- Also check that handlers are installed on all signals in set,
- and if not, install our dummy handler. This is conformant to
- POSIX: "The effect of sigwait() on the signal actions for the
- signals in set is unspecified." */
- __sigfillset(&mask);
- sigdelset(&mask, __pthread_sig_cancel);
- for (s = 1; s <= NSIG; s++) {
- if (sigismember(set, s) &&
- s != __pthread_sig_restart &&
- s != __pthread_sig_cancel &&
- s != __pthread_sig_debug) {
- sigdelset(&mask, s);
- if (sighandler[s].old == NULL ||
- sighandler[s].old == (arch_sighandler_t) SIG_DFL ||
- sighandler[s].old == (arch_sighandler_t) SIG_IGN) {
- memset(&sa, 0, sizeof(sa));
- sa.sa_handler = pthread_null_sighandler;
- sigaction(s, &sa, NULL);
- }
- }
- }
- /* Test for cancellation */
- if (sigsetjmp(jmpbuf, 1) == 0) {
- THREAD_SETMEM(self, p_cancel_jmp, &jmpbuf);
- if (! (THREAD_GETMEM(self, p_canceled)
- && THREAD_GETMEM(self, p_cancelstate) == PTHREAD_CANCEL_ENABLE)) {
- /* Reset the signal count */
- THREAD_SETMEM(self, p_signal, 0);
- /* Say we're in sigwait */
- THREAD_SETMEM(self, p_sigwaiting, 1);
- /* Unblock the signals and wait for them */
- sigsuspend(&mask);
- }
- }
- THREAD_SETMEM(self, p_cancel_jmp, NULL);
- /* The signals are now reblocked. Check for cancellation */
- pthread_testcancel();
- /* We should have self->p_signal != 0 and equal to the signal received */
- *sig = THREAD_GETMEM(self, p_signal);
- return 0;
- }
- /* Redefine raise() to send signal to calling thread only,
- as per POSIX 1003.1c */
- libpthread_hidden_proto(raise)
- int raise (int sig) {
- int ret;
- pid_t tid;
- tid = INLINE_SYSCALL(gettid, 0);
- ret = INLINE_SYSCALL(tkill, 2, tid, sig);
- return ret;
- }
- libpthread_hidden_def(raise)
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