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-rw-r--r--libc/sysdeps/linux/x86_64/sigaction.c135
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
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index 000000000..217fd2ae1
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+++ b/libc/sysdeps/linux/x86_64/sigaction.c
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+/* 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