| 1 | /* Copyright (C) 2001-2022 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 <sysdep.h> |
|---|
| 19 | #include <jmpbuf-offsets.h> |
|---|
| 20 | #include <tcb-offsets.h> |
|---|
| 21 | #include <asm-syntax.h> |
|---|
| 22 | |
|---|
| 23 | #include <signal-defines.h> |
|---|
| 24 | /* #include <signal.h> */ |
|---|
| 25 | #define SS_ONSTACK 1 |
|---|
| 26 | |
|---|
| 27 | .text |
|---|
| 28 | ENTRY (__longjmp) |
|---|
| 29 | movl 4(%esp), %eax /* User's jmp_buf in %eax. */ |
|---|
| 30 | |
|---|
| 31 | /* Save the return address now. */ |
|---|
| 32 | movl (JB_PC*4)(%eax), %edx |
|---|
| 33 | /* Get the stack pointer. */ |
|---|
| 34 | movl (JB_SP*4)(%eax), %ecx |
|---|
| 35 | cfi_undefined(%ecx) |
|---|
| 36 | #ifdef PTR_DEMANGLE |
|---|
| 37 | PTR_DEMANGLE (%edx) |
|---|
| 38 | PTR_DEMANGLE (%ecx) |
|---|
| 39 | #endif |
|---|
| 40 | |
|---|
| 41 | movw %ds, %si |
|---|
| 42 | movw %gs, %di |
|---|
| 43 | cmpw %si, %di |
|---|
| 44 | jz .Lok /* TLS not initialized yet */ |
|---|
| 45 | |
|---|
| 46 | movl %gs:SIGSTATE_OFFSET, %edi |
|---|
| 47 | testl %edi, %edi |
|---|
| 48 | jz .Lok /* sigstate not initialized yet */ |
|---|
| 49 | |
|---|
| 50 | testl $SS_ONSTACK, (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_FLAGS__OFFSET)(%edi) |
|---|
| 51 | jz .Lok |
|---|
| 52 | |
|---|
| 53 | /* We were on the alternate stack. */ |
|---|
| 54 | |
|---|
| 55 | cmpl (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_SP__OFFSET)(%edi), %ecx |
|---|
| 56 | jb .Loks /* We jump below the alternate stack, switch. */ |
|---|
| 57 | |
|---|
| 58 | movl (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_SP__OFFSET)(%edi), %ebx |
|---|
| 59 | addl (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_SIZE__OFFSET)(%edi), %ebx |
|---|
| 60 | cmpl %ebx, %ecx |
|---|
| 61 | jb .Lok /* We jump inside the alternate stack, do not switch. */ |
|---|
| 62 | |
|---|
| 63 | /* We jump above the alternate stack, switch. */ |
|---|
| 64 | |
|---|
| 65 | .Loks: /* We jump out of the alternate stack, clear SS_ONSTACK flag. */ |
|---|
| 66 | andl $~(SS_ONSTACK), (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_FLAGS__OFFSET)(%edi) |
|---|
| 67 | |
|---|
| 68 | .Lok: /* We add unwind information for the target here. */ |
|---|
| 69 | cfi_def_cfa(%eax, 0) |
|---|
| 70 | cfi_register(%eip, %edx) |
|---|
| 71 | cfi_register(%esp, %ecx) |
|---|
| 72 | cfi_offset(%ebx, JB_BX*4) |
|---|
| 73 | cfi_offset(%esi, JB_SI*4) |
|---|
| 74 | cfi_offset(%edi, JB_DI*4) |
|---|
| 75 | cfi_offset(%ebp, JB_BP*4) |
|---|
| 76 | /* Restore registers. */ |
|---|
| 77 | movl (JB_BX*4)(%eax), %ebx |
|---|
| 78 | movl (JB_SI*4)(%eax), %esi |
|---|
| 79 | movl (JB_DI*4)(%eax), %edi |
|---|
| 80 | movl (JB_BP*4)(%eax), %ebp |
|---|
| 81 | cfi_restore(%ebx) |
|---|
| 82 | cfi_restore(%esi) |
|---|
| 83 | cfi_restore(%edi) |
|---|
| 84 | cfi_restore(%ebp) |
|---|
| 85 | |
|---|
| 86 | movl 8(%esp), %eax /* Second argument is return value. */ |
|---|
| 87 | movl %ecx, %esp |
|---|
| 88 | |
|---|
| 89 | /* Jump to saved PC. */ |
|---|
| 90 | jmp *%edx |
|---|
| 91 | END (__longjmp) |
|---|
| 92 | |
|---|
