sysdeps/unix/sysv/linux/x86_64/____longjmp_chk.S

   1 /* Copyright (C) 2001-2024 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    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <sigaltstack-offsets.h>
  19
  20         .section .rodata.str1.1,"aMS",@progbits,1
  21         .type   longjmp_msg,@object
  22 longjmp_msg:
  23         .string "longjmp causes uninitialized stack frame"
  24         .size   longjmp_msg, .-longjmp_msg
  25
  26 #ifdef PIC
  27 # define LOAD_MSG       lea     longjmp_msg(%rip), %RDI_LP
  28 #else
  29 # define LOAD_MSG       mov     $longjmp_msg, %RDI_LP
  30 #endif
  31
  32 #define CHECK_INVALID_LONGJMP \
  33         cmp     %R8_LP, %RSP_LP;                                        \
  34         jbe     .Lok;                                                   \
  35         /* Save function parameters.  */                                \
  36         movq    %rdi, %r10;                                             \
  37         cfi_register (%rdi, %r10);                                      \
  38         movl    %esi, %ebx;                                             \
  39         cfi_register (%rsi, %rbx);                                      \
  40         xorl    %edi, %edi;                                             \
  41         lea     -sizeSS(%rsp), %RSI_LP;                                 \
  42         movl    $__NR_sigaltstack, %eax;                                \
  43         syscall;                                                        \
  44         /* Without working sigaltstack we cannot perform the test.  */  \
  45         testl   %eax, %eax;                                             \
  46         jne     .Lok2;                                                  \
  47         testl   $1, (-sizeSS + oSS_FLAGS)(%rsp);                        \
  48         jz      .Lfail;                                                 \
  49         mov     (-sizeSS + oSS_SP)(%rsp), %RAX_LP;                      \
  50         add     (-sizeSS + oSS_SIZE)(%rsp), %RAX_LP;                    \
  51         sub     %R8_LP, %RAX_LP;                                        \
  52         cmp     (-sizeSS + oSS_SIZE)(%rsp), %RAX_LP;                    \
  53         jae     .Lok2;                                                  \
  54 .Lfail:                                                                 \
  55         sub     $8, %RSP_LP;                                            \
  56         cfi_remember_state;                                             \
  57         cfi_def_cfa_offset(16);                                         \
  58         LOAD_MSG;                                                       \
  59         call    HIDDEN_JUMPTARGET(__fortify_fail);                      \
  60         cfi_restore_state;                                              \
  61         .p2align 3, 5;                                                          \
  62 .Lok2:                                                                  \
  63         movq    %r10, %rdi;                                             \
  64         cfi_restore (%rdi);                                             \
  65         movl    %ebx, %esi;                                             \
  66         cfi_restore (%rsi);                                             \
  67 .Lok:
  68
  69 #define __longjmp ____longjmp_chk
  70 #include <__longjmp.S>