diff options
Diffstat (limited to 'libc/sysdeps/linux/x86_64/sigaction.c')
| -rw-r--r-- | libc/sysdeps/linux/x86_64/sigaction.c | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/libc/sysdeps/linux/x86_64/sigaction.c b/libc/sysdeps/linux/x86_64/sigaction.c new file mode 100644 index 000000000..217fd2ae1 --- /dev/null +++ b/libc/sysdeps/linux/x86_64/sigaction.c @@ -0,0 +1,135 @@ +/* POSIX.1 `sigaction' call for Linux/x86-64. + Copyright (C) 2001, 2002, 2003 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 <errno.h> +#include <signal.h> +#include <string.h> +#include <sys/syscall.h> +#include <bits/kernel_sigaction.h> + +#define SA_RESTORER 0x04000000 + + +#if defined __NR_rt_sigaction +#warning "Yes there are two warnings here. Don't worry about it." +static void restore_rt (void) asm ("__restore_rt"); +static void restore (void) asm ("__restore"); + +/* 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; +} +#else + +#warning "Yes there is a warning here. Don't worry about it." +static void restore (void) asm ("__restore"); + +/* 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 old_kernel_sigaction kact, koact; + +#ifdef SIGCANCEL + if (sig == SIGCANCEL) { + __set_errno (EINVAL); + return -1; + } +#endif + + if (act) { + kact.k_sa_handler = act->sa_handler; + kact.sa_mask = act->sa_mask.__val[0]; + kact.sa_flags = act->sa_flags | SA_RESTORER; + kact.sa_restorer = &restore; + } + + asm volatile ("syscall\n" + : "=a" (result) + : "0" (__NR_sigaction), "mr" (sig), + "c" (act ? __ptrvalue (&kact) : 0), + "d" (oact ? __ptrvalue (&koact) : 0)); + + if (result < 0) { + __set_errno(-result); + return -1; + } + + if (oact) { + oact->sa_handler = koact.k_sa_handler; + oact->sa_mask.__val[0] = koact.sa_mask; + oact->sa_flags = koact.sa_flags; + oact->sa_restorer = koact.sa_restorer; + } + return result; +} +#endif + +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 \ + ( \ + ".text\n" \ + ".align 16\n" \ + "__" #name ":\n" \ + " movq $" #syscall ", %rax\n" \ + " syscall\n" \ + ); +#ifdef __NR_rt_sigaction +/* The return code for realtime-signals. */ +RESTORE (restore_rt, __NR_rt_sigreturn) +#endif +#ifdef __NR_sigreturn +RESTORE (restore, __NR_sigreturn) +#endif |