diff options
Diffstat (limited to 'libc/sysdeps/linux/alpha/rt_sigaction.S')
| -rw-r--r-- | libc/sysdeps/linux/alpha/rt_sigaction.S | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/libc/sysdeps/linux/alpha/rt_sigaction.S b/libc/sysdeps/linux/alpha/rt_sigaction.S new file mode 100644 index 000000000..98d80c9d8 --- /dev/null +++ b/libc/sysdeps/linux/alpha/rt_sigaction.S @@ -0,0 +1,82 @@ +/* Copyright (C) 1998, 2003, 2004 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Richard Henderson <rth@cygnus.com>, 1998 + + 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 <features.h> +#include <sys/syscall.h> +#include <asm/regdef.h> +#include <asm/pal.h> + +/* On Alpha we desparately want to avoid having to issue an imb. Ordinarily + the kernel would have to issue one after setting up the signal return + stack, but the Linux rt_sigaction syscall is prepared to accept a pointer + to the sigreturn syscall, instead of inlining it on the stack. + + This just about halves signal delivery time. */ + + .text + +.globl __syscall_rt_sigaction +.align 4 +.ent __syscall_rt_sigaction, 0 +__syscall_rt_sigaction: + .frame sp,0,ra,0 + ldgp gp,0(pv) + .prologue 1 + + beq a1, 0f + ldl t0, 8(a1) # sa_flags + + /* The unwinder will subtract one from the return address when + attempting to find the call instruction that led us here. + Since we didn't get here via a normal call, if we do nothing + we would pick up the wrong symbol and the wrong FDE. Account + for this by adding a nop to the start of the function and + then skipping it here by adding 4. */ + ldah a4, __syscall_sigreturn+4(gp) !gprelhigh + ldah t1, __syscall_rt_sigreturn+4(gp) !gprelhigh + lda a4, __syscall_sigreturn+4(a4) !gprellow + lda t1, __syscall_rt_sigreturn+4(t1) !gprellow + and t0, 0x40, t0 # SA_SIGINFO + cmovne t0, t1, a4 + +0: ldi v0, __NR_rt_sigaction + callsys + bne a3, $error + ret + +$error: + jmp zero,__syscall_error + +.end __syscall_rt_sigaction + +__syscall_sigreturn: + nop + mov sp, a0 + ldi v0, __NR_sigreturn + callsys + .size __syscall_sigreturn, .-__syscall_sigreturn + .type __syscall_sigreturn, @function + +__syscall_rt_sigreturn: + nop + mov sp,a0 + ldi v0,__NR_rt_sigreturn + callsys + .size __syscall_rt_sigreturn, .-__syscall_rt_sigreturn + .type __syscall_rt_sigreturn, @function |