diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/x86_64/sigaction.c')
| -rw-r--r-- | sysdeps/unix/sysv/linux/x86_64/sigaction.c | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/x86_64/sigaction.c b/sysdeps/unix/sysv/linux/x86_64/sigaction.c new file mode 100644 index 0000000000..5aa8b9f43b --- /dev/null +++ b/sysdeps/unix/sysv/linux/x86_64/sigaction.c @@ -0,0 +1,99 @@ +/* POSIX.1 `sigaction' call for Linux/x86-64. + Copyright (C) 2001 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + 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, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <sysdep.h> +#include <errno.h> +#include <stddef.h> +#include <signal.h> +#include <string.h> + +#include <sysdep.h> +#include <sys/syscall.h> + +#include <kernel-features.h> + +/* The difference here is that the sigaction structure used in the + kernel is not the same as we use in the libc. Therefore we must + translate it here. */ +#include <kernel_sigaction.h> + +/* We do not globally define the SA_RESTORER flag so do it here. */ +#define SA_RESTORER 0x04000000 + +extern int __syscall_rt_sigaction (int, const struct kernel_sigaction *__unbounded, + struct kernel_sigaction *__unbounded, size_t); + +static void restore_rt (void) asm ("__restore_rt"); + + +/* If ACT is not NULL, change the action for SIG to *ACT. + If OACT is not NULL, put the old action for SIG in *OACT. */ +int +__libc_sigaction (int sig, const struct sigaction *act, struct sigaction *oact) +{ + int result; + struct kernel_sigaction kact, koact; + + if (act) + { + kact.k_sa_handler = act->sa_handler; + memcpy (&kact.sa_mask, &act->sa_mask, sizeof (sigset_t)); + kact.sa_flags = act->sa_flags | SA_RESTORER; + + kact.sa_restorer = &restore_rt; + } + + /* XXX The size argument hopefully will have to be changed to the + real size of the user-level sigset_t. */ + result = INLINE_SYSCALL (rt_sigaction, 4, + sig, act ? __ptrvalue (&kact) : NULL, + oact ? __ptrvalue (&koact) : NULL, _NSIG / 8); + if (oact && result >= 0) + { + oact->sa_handler = koact.k_sa_handler; + memcpy (&oact->sa_mask, &koact.sa_mask, sizeof (sigset_t)); + oact->sa_flags = koact.sa_flags; + oact->sa_restorer = koact.sa_restorer; + } + return result; +} + +weak_alias (__libc_sigaction, __sigaction) +weak_alias (__libc_sigaction, sigaction) + +/* NOTE: Please think twice before making any changes to the bits of + code below. GDB needs some intimate knowledge about it to + recognize them as signal trampolines, and make backtraces through + signal handlers work right. Important are both the names + (__restore_rt) and the exact instruction sequence. + If you ever feel the need to make any changes, please notify the + appropriate GDB maintainer. */ + +#define RESTORE(name, syscall) RESTORE2 (name, syscall) +#define RESTORE2(name, syscall) \ +asm \ + ( \ + ".align 16\n" \ + "__" #name ":\n" \ + " movq $" #syscall ", %rax\n" \ + " syscall\n" \ + ); + +/* The return code for realtime-signals. */ +RESTORE (restore_rt, __NR_rt_sigreturn) |