sysdeps/x86_64/__longjmp.S

   1 /* Copyright (C) 2001-2014 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #include <sysdep.h>
  19 #include <jmpbuf-offsets.h>
  20 #include <asm-syntax.h>
  21 #include <stap-probe.h>
  22
  23 /* Jump to the position specified by ENV, causing the
  24    setjmp call there to return VAL, or 1 if VAL is 0.
  25    void __longjmp (__jmp_buf env, int val).  */
  26         .text
  27 ENTRY(__longjmp)
  28         /* Restore registers.  */
  29         mov (JB_RSP*8)(%rdi),%R8_LP
  30         mov (JB_RBP*8)(%rdi),%R9_LP
  31         mov (JB_PC*8)(%rdi),%RDX_LP
  32 #ifdef PTR_DEMANGLE
  33         PTR_DEMANGLE (%R8_LP)
  34         PTR_DEMANGLE (%R9_LP)
  35         PTR_DEMANGLE (%RDX_LP)
  36 # ifdef __ILP32__
  37         /* We ignored the high bits of the %rbp value because only the low
  38            bits are mangled.  But we cannot presume that %rbp is being used
  39            as a pointer and truncate it, so recover the high bits.  */
  40         movl (JB_RBP*8 + 4)(%rdi), %eax
  41         shlq $32, %rax
  42         orq %rax, %r9
  43 # endif
  44 #endif
  45         LIBC_PROBE (longjmp, 3, LP_SIZE@%RDI_LP, -4@%esi, LP_SIZE@%RDX_LP)
  46         /* We add unwind information for the target here.  */
  47         cfi_def_cfa(%rdi, 0)
  48         cfi_register(%rsp,%r8)
  49         cfi_register(%rbp,%r9)
  50         cfi_register(%rip,%rdx)
  51         cfi_offset(%rbx,JB_RBX*8)
  52         cfi_offset(%r12,JB_R12*8)
  53         cfi_offset(%r13,JB_R13*8)
  54         cfi_offset(%r14,JB_R14*8)
  55         cfi_offset(%r15,JB_R15*8)
  56         movq (JB_RBX*8)(%rdi),%rbx
  57         movq (JB_R12*8)(%rdi),%r12
  58         movq (JB_R13*8)(%rdi),%r13
  59         movq (JB_R14*8)(%rdi),%r14
  60         movq (JB_R15*8)(%rdi),%r15
  61         /* Set return value for setjmp.  */
  62         mov %esi, %eax
  63         mov %R8_LP,%RSP_LP
  64         movq %r9,%rbp
  65         LIBC_PROBE (longjmp_target, 3,
  66                     LP_SIZE@%RDI_LP, -4@%eax, LP_SIZE@%RDX_LP)
  67         jmpq *%rdx
  68 END (__longjmp)