diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/alpha/rt_sigaction.S')
| -rw-r--r-- | sysdeps/unix/sysv/linux/alpha/rt_sigaction.S | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/alpha/rt_sigaction.S b/sysdeps/unix/sysv/linux/alpha/rt_sigaction.S new file mode 100644 index 0000000000..2cde160ec3 --- /dev/null +++ b/sysdeps/unix/sysv/linux/alpha/rt_sigaction.S @@ -0,0 +1,120 @@ +/* Copyright (C) 1998-2014 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, see + <http://www.gnu.org/licenses/>. */ + +#include <sysdep.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 + +ENTRY(__syscall_rt_sigaction) + cfi_startproc + ldgp gp,0(pv) +#ifdef PROF + .set noat + lda AT, _mcount + jsr AT, (AT), _mcount + .set at +#endif + .prologue 1 + + beq a1, 0f + ldl t0, 8(a1) # sa_flags + + ldah a4, __syscall_sigreturn(gp) !gprelhigh + ldah t1, __syscall_rt_sigreturn(gp) !gprelhigh + lda a4, __syscall_sigreturn(a4) !gprellow + lda t1, __syscall_rt_sigreturn(t1) !gprellow + and t0, 0x40, t0 # SA_SIGINFO + cmovne t0, t1, a4 + +0: ldi v0, __NR_rt_sigaction + callsys + bne a3, SYSCALL_ERROR_LABEL + ret + cfi_endproc +PSEUDO_END(__syscall_rt_sigaction) + +/* To enable unwinding through the signal frame without special hackery + elsewhere, describe the entire struct sigcontext with unwind info. + + In order to minimize the size of the encoding, we set the CFA to the + end of the sigcontext, which makes all of the registers have small + negative offsets from that. */ + + .macro SIGCONTEXT_REGS_I base, from=0 + cfi_offset (\from, \base + (4 + \from) * 8) + .if 30-\from + SIGCONTEXT_REGS_I \base, "(\from+1)" + .endif + .endm + + .macro SIGCONTEXT_REGS_F base, from=32 + cfi_offset (\from, \base + (4 + 1 + \from) * 8) + .if 62-\from + SIGCONTEXT_REGS_F \base, "(\from+1)" + .endif + .endm + + .macro SIGCONTEXT_REGS base + SIGCONTEXT_REGS_I \base + SIGCONTEXT_REGS_F \base + cfi_offset (63, \base + (4 + 32 + 1 + 32) * 8) + cfi_offset (64, \base + 2 * 8) + .endm + + cfi_startproc + cfi_return_column (64) + .cfi_signal_frame + SIGCONTEXT_REGS -648 + cfi_def_cfa_offset (648) + + /* While this frame is marked as a signal frame, that only applies + to how this return address is handled for the outer frame. + The return address that arrived here, from the inner frame, is + not marked as a signal frame and so the unwinder still tries to + subtract 1 to examine the presumed call insn. Thus we must + extend the unwind info to a nop before the start. */ + nop + .align 4 + +__syscall_sigreturn: + mov sp, a0 + ldi v0, __NR_sigreturn + callsys + .size __syscall_sigreturn, .-__syscall_sigreturn + .type __syscall_sigreturn, @function + + /* See above wrt including the nop. */ + cfi_def_cfa_offset (176 + 648) + nop + .align 4 + +__syscall_rt_sigreturn: + mov sp,a0 + ldi v0,__NR_rt_sigreturn + callsys + .size __syscall_rt_sigreturn, .-__syscall_rt_sigreturn + .type __syscall_rt_sigreturn, @function + + cfi_endproc |