diff options
Diffstat (limited to 'sysdeps/mach/hurd/i386/____longjmp_chk.S')
| -rw-r--r-- | sysdeps/mach/hurd/i386/____longjmp_chk.S | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/sysdeps/mach/hurd/i386/____longjmp_chk.S b/sysdeps/mach/hurd/i386/____longjmp_chk.S new file mode 100644 index 0000000000..f499fbd1e7 --- /dev/null +++ b/sysdeps/mach/hurd/i386/____longjmp_chk.S @@ -0,0 +1,107 @@ +/* Copyright (C) 2001-2012 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) + PTR_DEMANGLE (%edx) + PTR_DEMANGLE (%edi) + + 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) |