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ab18b1e1a3
* sysdeps/unix/sysv/linux/i386/sigaction.c: Make alias weak since it's overridden by libpthreads. * sysdeps/unix/sysv/linux/sigaction.c: Likewise. * sysdeps/unix/sysv/linux/arm/sigaction.c: Likewise. * sysdeps/unix/sysv/linux/ia64/sigaction.c: Likewise. * sysdeps/unix/sysv/linux/sparc/sparc32/sigaction.c: Likewise. * sysdeps/unix/sysv/linux/sparc/sparc64/sigaction.c: Likewise.
190 lines
5.3 KiB
C
190 lines
5.3 KiB
C
/* POSIX.1 `sigaction' call for Linux/i386.
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Copyright (C) 1991, 95, 96, 97, 98, 99, 2000 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Library General Public License as
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published by the Free Software Foundation; either version 2 of the
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License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with the GNU C Library; see the file COPYING.LIB. If not,
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write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#include <sysdep.h>
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#include <errno.h>
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#include <stddef.h>
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#include <signal.h>
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#include <string.h>
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#include <sysdep.h>
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#include <sys/syscall.h>
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#include <kernel-features.h>
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/* The difference here is that the sigaction structure used in the
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kernel is not the same as we use in the libc. Therefore we must
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translate it here. */
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#include <kernel_sigaction.h>
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/* We do not globally define the SA_RESTORER flag so do it here. */
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#define SA_RESTORER 0x04000000
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extern int __syscall_rt_sigaction (int, const struct kernel_sigaction *__unbounded,
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struct kernel_sigaction *__unbounded, size_t);
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#if __ASSUME_REALTIME_SIGNALS == 0
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/* The variable is shared between all wrappers around signal handling
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functions which have RT equivalents. */
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int __libc_missing_rt_sigs;
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#endif
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#ifdef __NR_rt_sigaction
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static void restore_rt (void) asm ("__restore_rt");
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#endif
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static void restore (void) asm ("__restore");
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/* If ACT is not NULL, change the action for SIG to *ACT.
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If OACT is not NULL, put the old action for SIG in *OACT. */
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int
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__libc_sigaction (int sig, const struct sigaction *act, struct sigaction *oact)
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{
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#if __ASSUME_REALTIME_SIGNALS == 0
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struct old_kernel_sigaction k_newact, k_oldact;
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#endif
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int result;
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#ifdef __NR_rt_sigaction
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/* First try the RT signals. */
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# if __ASSUME_REALTIME_SIGNALS == 0
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if (!__libc_missing_rt_sigs)
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# endif
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{
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struct kernel_sigaction kact, koact;
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# if __ASSUME_REALTIME_SIGNALS == 0
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int saved_errno = errno;
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# endif
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if (act)
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{
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kact.k_sa_handler = act->sa_handler;
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memcpy (&kact.sa_mask, &act->sa_mask, sizeof (sigset_t));
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kact.sa_flags = act->sa_flags | SA_RESTORER;
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kact.sa_restorer = ((act->sa_flags & SA_SIGINFO)
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? &restore_rt : &restore);
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}
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/* XXX The size argument hopefully will have to be changed to the
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real size of the user-level sigset_t. */
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result = INLINE_SYSCALL (rt_sigaction, 4,
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sig, act ? __ptrvalue (&kact) : NULL,
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oact ? __ptrvalue (&koact) : NULL, _NSIG / 8);
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# if __ASSUME_REALTIME_SIGNALS == 0
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if (result >= 0 || errno != ENOSYS)
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# endif
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{
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if (oact && result >= 0)
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{
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oact->sa_handler = koact.k_sa_handler;
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memcpy (&oact->sa_mask, &koact.sa_mask, sizeof (sigset_t));
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oact->sa_flags = koact.sa_flags;
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oact->sa_restorer = koact.sa_restorer;
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}
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return result;
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}
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# if __ASSUME_REALTIME_SIGNALS == 0
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__set_errno (saved_errno);
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__libc_missing_rt_sigs = 1;
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# endif
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}
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#endif
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#if __ASSUME_REALTIME_SIGNALS == 0
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if (act)
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{
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k_newact.k_sa_handler = act->sa_handler;
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k_newact.sa_mask = act->sa_mask.__val[0];
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k_newact.sa_flags = act->sa_flags | SA_RESTORER;
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k_newact.sa_restorer = &restore;
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}
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asm volatile ("pushl %%ebx\n"
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"movl %2, %%ebx\n"
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"int $0x80\n"
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"popl %%ebx"
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: "=a" (result)
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: "0" (SYS_ify (sigaction)), "r" (sig),
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"c" (act ? __ptrvalue (&k_newact) : 0),
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"d" (oact ? __ptrvalue (&k_oldact) : 0));
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if (result < 0)
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{
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__set_errno (-result);
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return -1;
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}
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if (oact)
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{
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oact->sa_handler = k_oldact.k_sa_handler;
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oact->sa_mask.__val[0] = k_oldact.sa_mask;
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oact->sa_flags = k_oldact.sa_flags;
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oact->sa_restorer = k_oldact.sa_restorer;
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}
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return 0;
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#endif
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}
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weak_alias (__libc_sigaction, __sigaction)
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weak_alias (__libc_sigaction, sigaction)
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/* NOTE: Please think twice before making any changes to the bits of
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code below. GDB needs some intimate knowledge about it to
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recognize them as signal trampolines, and make backtraces through
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signal handlers work right. Important are both the names
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(__restore and __restore_rt) and the exact instruction sequence.
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If you ever feel the need to make any changes, please notify the
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appropriate GDB maintainer. */
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#define RESTORE(name, syscall) RESTORE2 (name, syscall)
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#define RESTORE2(name, syscall) \
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asm \
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( \
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".align 16\n" \
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"__" #name ":\n" \
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" movl $" #syscall ", %eax\n" \
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" int $0x80" \
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);
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#ifdef __NR_rt_sigaction
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/* The return code for realtime-signals. */
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RESTORE (restore_rt, __NR_rt_sigreturn)
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#endif
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/* For the boring old signals. */
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# undef RESTORE2
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# define RESTORE2(name, syscall) \
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asm \
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( \
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".align 8\n" \
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"__" #name ":\n" \
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" popl %eax\n" \
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" movl $" #syscall ", %eax\n" \
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" int $0x80" \
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);
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RESTORE (restore, __NR_sigreturn)
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