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/* Copyright (C) 2001-2015 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, see
<http://www.gnu.org/licenses/>. */
#include <sysdep.h>
#include <jmpbuf-offsets.h>
#include <asm-syntax.h>
#include <signal-defines.h>
/* #include <signal.h> */
#define SS_ONSTACK 1
.section .rodata.str1.1,"aMS",@progbits,1
.type longjmp_msg,@object
longjmp_msg:
.string "longjmp causes uninitialized stack frame"
.size longjmp_msg, .-longjmp_msg
#ifdef PIC
# define CALL_FAIL movl %ebx, %ecx; /* TODO: what's this mov good for? */ \
cfi_register(%ebx,%ecx); \
LOAD_PIC_REG (bx); \
leal longjmp_msg@GOTOFF(%ebx), %eax; \
call HIDDEN_JUMPTARGET(__fortify_fail)
#else
# define CALL_FAIL movl $longjmp_msg, %eax; \
call HIDDEN_JUMPTARGET(__fortify_fail)
#endif
.text
ENTRY (____longjmp_chk)
movl 4(%esp), %ecx /* User's jmp_buf in %ecx. */
/* Save the return address now. */
movl (JB_PC*4)(%ecx), %edx
/* Get the stack pointer. */
movl (JB_SP*4)(%ecx), %edi
cfi_undefined(%edi)
#ifdef PTR_DEMANGLE
PTR_DEMANGLE (%edx)
PTR_DEMANGLE (%edi)
#endif
cmpl %edi, %esp
/* Jumping to a higher-address frame is always allowed. */
jbe .Lok
/* Passing here, we're either about to do something invalid, or we're
executing on an alternative signal stack. */
/* TODO: need locking? */
/* struct hurd_sigstate * _hurd_self_sigstate (void) */
call _hurd_self_sigstate
/* TODO: %eax and %eax->sigaltstack are always valid? */
testl $SS_ONSTACK, (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_FLAGS__OFFSET)(%eax)
/* Fail if SS_ONSTACK is not set. */
jz .Lfail
movl (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_SP__OFFSET)(%eax), %ebx
addl (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_SIZE__OFFSET)(%eax), %ebx
subl %edi, %ebx
cmpl (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_SIZE__OFFSET)(%eax), %ebx
/* TODO: comment this calculation. */
jae .Lok
.Lfail: CALL_FAIL
.Lok: /* We add unwind information for the target here. */
cfi_def_cfa(%ecx, 0)
cfi_register(%eip, %edx)
cfi_register(%esp, %edi)
cfi_offset(%ebx, JB_BX*4)
cfi_offset(%esi, JB_SI*4)
cfi_offset(%edi, JB_DI*4)
cfi_offset(%ebp, JB_BP*4)
movl 8(%esp), %eax /* Second argument is return value. */
movl %edi, %esp
/* Restore registers. */
movl (JB_BX*4)(%ecx), %ebx
movl (JB_SI*4)(%ecx), %esi
movl (JB_DI*4)(%ecx), %edi
movl (JB_BP*4)(%ecx), %ebp
cfi_restore(%ebx)
cfi_restore(%esi)
cfi_restore(%edi)
cfi_restore(%ebp)
/* Jump to saved PC. */
jmp *%edx
END (____longjmp_chk)
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