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109 lines
3.6 KiB
C
109 lines
3.6 KiB
C
/* POSIX.1 `sigaction' call for Linux/x86-64.
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Copyright (C) 2001, 2002, 2003 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 Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the 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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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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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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/* Using the hidden attribute here does not change the code but it
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helps to avoid warnings. */
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#if defined HAVE_HIDDEN && defined HAVE_VISIBILITY_ATTRIBUTE \
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&& !defined HAVE_BROKEN_VISIBILITY_ATTRIBUTE
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extern void restore_rt (void) asm ("__restore_rt") attribute_hidden;
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#else
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static void restore_rt (void) asm ("__restore_rt");
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#endif
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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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int result;
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struct kernel_sigaction kact, koact;
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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 = &restore_rt;
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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 (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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libc_hidden_def (__libc_sigaction)
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#ifndef LIBC_SIGACTION
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weak_alias (__libc_sigaction, __sigaction)
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libc_hidden_weak (__sigaction)
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weak_alias (__libc_sigaction, sigaction)
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#endif
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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_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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CFI_STARTPROC "\n" \
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"__" #name ":\n" \
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" movq $" #syscall ", %rax\n" \
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" syscall\n" \
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CFI_ENDPROC "\n" \
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);
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/* The return code for realtime-signals. */
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RESTORE (restore_rt, __NR_rt_sigreturn)
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