146 lines
3.8 KiB
C
146 lines
3.8 KiB
C
/* POSIX.1 `sigaction' call for Linux/i386.
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Copyright (C) 1991, 1995, 1996, 1997 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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/* 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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extern int __syscall_rt_sigaction (int, const struct sigaction *,
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struct sigaction *, size_t);
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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_have_rt_sigs = -1;
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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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__sigaction (int sig, const struct sigaction *act, struct sigaction *oact)
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{
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struct old_kernel_sigaction k_newact, k_oldact;
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int result;
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/* First try the RT signals. */
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if (__libc_have_rt_sigs)
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{
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struct sigaction nact, *nactp;
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if (act)
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{
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nact.sa_handler = act->sa_handler;
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memcpy (&nact.sa_mask, &act->sa_mask, sizeof (sigset_t));
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nact.sa_flags = act->sa_flags;
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nact.sa_restorer = ((act->sa_flags & SA_NOMASK)
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? &&restore_nomask : &&restore);
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nactp = &nact;
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}
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else
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nactp = NULL;
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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 = __syscall_rt_sigaction (sig, nactp, oact, _NSIG / 8);
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if (result >= 0 || errno != ENOSYS)
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return result;
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__libc_have_rt_sigs = 0;
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}
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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;
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k_newact.sa_restorer = ((act->sa_flags & SA_NOMASK)
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? &&restore_nomask : &&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 ? &k_newact : 0), "d" (oact ? &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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restore:
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asm (
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#ifdef PIC
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" pushl %%ebx\n"
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" call 0f\n"
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"0: popl %%ebx\n"
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" addl $_GLOBAL_OFFSET_TABLE_+[.-0b], %%ebx\n"
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" addl $8, %%esp\n"
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" call __sigsetmask@PLT\n"
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" addl $8, %%esp\n"
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" popl %%ebx\n"
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#else
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" addl $4, %%esp\n"
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" call __sigsetmask\n"
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" addl $4, %%esp\n"
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#endif
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" popl %%eax\n"
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" popl %%ecx\n"
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" popl %%edx\n"
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" popf\n"
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" ret"
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: : );
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restore_nomask:
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asm (" addl $4, %%esp\n"
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" popl %%eax\n"
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" popl %%ecx\n"
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" popl %%edx\n"
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" popf\n"
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" ret"
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: : );
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/* NOTREACHED */
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return -1;
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}
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weak_alias (__sigaction, sigaction)
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