cosmopolitan/libc/calls/sigenter.S

49 lines
2.5 KiB
ArmAsm

/*-*- mode:unix-assembly; indent-tabs-mode:t; tab-width:8; coding:utf-8 -*-│
vi: set et ft=asm ts=8 tw=8 fenc=utf-8 :vi
Copyright 2020 Justine Alexandra Roberts Tunney
Permission to use, copy, modify, and/or distribute this software for
any purpose with or without fee is hereby granted, provided that the
above copyright notice and this permission notice appear in all copies.
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
PERFORMANCE OF THIS SOFTWARE.
*/
#include "libc/calls/internal.h"
#include "libc/macros.h"
.source __FILE__
/ System Five signal handler.
/
/ This is needed because (1) a signal is allowed to trigger at
/ just about any time, and leaf functions (e.g. memcpy) aren't
/ required to leave Cosmopolitan's image base register alone.
/
/ @param %edi is the signal number
/ @param %rsi will be passed for sigactions
/ @param %rdx will be passed for sigactions
/ @return true if handler was invoked
__sigenter:
push %rbp
mov %rsp,%rbp
.profilable
and $NSIG-1,%edi
mov g_sighandrvas(,%rdi,4),%eax
cmp $kSigactionMinRva,%eax
jl 2f
lea _base(%rax),%eax
call *%rax
mov $1,%eax
1: leave
ret
2: xor %eax,%eax
jmp 1b
.endfn __sigenter,globl,hidden