sysdeps/i386/__longjmp.S

   1 /* longjmp for i386.
   2    Copyright (C) 1995-2015 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <sysdep.h>
  20 #include <jmpbuf-offsets.h>
  21 #include <asm-syntax.h>
  22 #include <stap-probe.h>
  23
  24         .text
  25 ENTRY (__longjmp)
  26 #ifdef PTR_DEMANGLE
  27         movl 4(%esp), %eax      /* User's jmp_buf in %eax.  */
  28
  29         /* Save the return address now.  */
  30         movl (JB_PC*4)(%eax), %edx
  31         /* Get the stack pointer.  */
  32         movl (JB_SP*4)(%eax), %ecx
  33         PTR_DEMANGLE (%edx)
  34         PTR_DEMANGLE (%ecx)
  35         LIBC_PROBE (longjmp, 3, 4@%eax, -4@8(%esp), 4@%edx)
  36         cfi_def_cfa(%eax, 0)
  37         cfi_register(%eip, %edx)
  38         cfi_register(%esp, %ecx)
  39         cfi_offset(%ebx, JB_BX*4)
  40         cfi_offset(%esi, JB_SI*4)
  41         cfi_offset(%edi, JB_DI*4)
  42         cfi_offset(%ebp, JB_BP*4)
  43         /* Restore registers.  */
  44         movl (JB_BX*4)(%eax), %ebx
  45         movl (JB_SI*4)(%eax), %esi
  46         movl (JB_DI*4)(%eax), %edi
  47         movl (JB_BP*4)(%eax), %ebp
  48         cfi_restore(%ebx)
  49         cfi_restore(%esi)
  50         cfi_restore(%edi)
  51         cfi_restore(%ebp)
  52
  53         LIBC_PROBE (longjmp_target, 3, 4@%eax, -4@8(%esp), 4@%edx)
  54         movl 8(%esp), %eax      /* Second argument is return value.  */
  55         movl %ecx, %esp
  56 #else
  57         movl 4(%esp), %ecx      /* User's jmp_buf in %ecx.  */
  58         movl 8(%esp), %eax      /* Second argument is return value.  */
  59         /* Save the return address now.  */
  60         movl (JB_PC*4)(%ecx), %edx
  61         LIBC_PROBE (longjmp, 3, 4@%ecx, -4@%eax, 4@%edx)
  62         /* Restore registers.  */
  63         movl (JB_BX*4)(%ecx), %ebx
  64         movl (JB_SI*4)(%ecx), %esi
  65         movl (JB_DI*4)(%ecx), %edi
  66         movl (JB_BP*4)(%ecx), %ebp
  67         movl (JB_SP*4)(%ecx), %esp
  68         LIBC_PROBE (longjmp_target, 3, 4@%ecx, -4@%ecx, 4@%edx)
  69 #endif
  70         /* Jump to saved PC.  */
  71         jmp *%edx
  72 END (__longjmp)