| /* Copyright (C) 1999-2018 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> |
| |
| /* If no SA_RESTORER function was specified by the application we use |
| one of these. This avoids the need for the kernel to synthesise a return |
| instruction on the stack, which would involve expensive cache flushes. |
| |
| Nowadays (2.6 series, and somewhat earlier) the kernel uses a high page |
| for signal trampolines, so the cache flushes are not an issue. But since |
| we do not have a vDSO, continue to use these so that we can provide |
| unwind information. |
| |
| Start the unwind tables at least one instruction before the signal |
| trampoline, because the unwinder will assume we are returning after |
| a call site. */ |
| |
| /* Used in ENTRY. */ |
| #undef cfi_startproc |
| #define cfi_startproc \ |
| .cfi_startproc simple; \ |
| .cfi_signal_frame |
| |
| /* The CFA is not computed / used correctly here; this is neither trivial to |
| do, nor is it needed. */ |
| #define CFI \ |
| cfi_def_cfa (sp, 0); \ |
| cfi_offset (r0, OFFSET + 0 * 4); \ |
| cfi_offset (r1, OFFSET + 1 * 4); \ |
| cfi_offset (r2, OFFSET + 2 * 4); \ |
| cfi_offset (r3, OFFSET + 3 * 4); \ |
| cfi_offset (r4, OFFSET + 4 * 4); \ |
| cfi_offset (r5, OFFSET + 5 * 4); \ |
| cfi_offset (r6, OFFSET + 6 * 4); \ |
| cfi_offset (r7, OFFSET + 7 * 4); \ |
| cfi_offset (r8, OFFSET + 8 * 4); \ |
| cfi_offset (r9, OFFSET + 9 * 4); \ |
| cfi_offset (r10, OFFSET + 10 * 4); \ |
| cfi_offset (r11, OFFSET + 11 * 4); \ |
| cfi_offset (r12, OFFSET + 12 * 4); \ |
| cfi_offset (r13, OFFSET + 13 * 4); \ |
| cfi_offset (r14, OFFSET + 14 * 4); \ |
| cfi_offset (r15, OFFSET + 15 * 4) |
| |
| #define OFFSET 32 |
| .fnstart |
| .save {r0-r15} |
| .pad #OFFSET |
| nop |
| ENTRY(__default_sa_restorer) |
| CFI |
| mov r7, $SYS_ify(sigreturn) |
| swi 0x0 |
| .fnend |
| END(__default_sa_restorer) |
| #undef OFFSET |
| |
| #define OFFSET 160 |
| .fnstart |
| .save {r0-r15} |
| .pad #OFFSET |
| nop |
| ENTRY(__default_rt_sa_restorer) |
| CFI |
| mov r7, $SYS_ify(rt_sigreturn) |
| swi 0x0 |
| .fnend |
| END(__default_rt_sa_restorer) |
| #undef OFFSET |