diff options
Diffstat (limited to 'libc/sysdeps/linux/aarch64/__longjmp.S')
| -rw-r--r-- | libc/sysdeps/linux/aarch64/__longjmp.S | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/libc/sysdeps/linux/aarch64/__longjmp.S b/libc/sysdeps/linux/aarch64/__longjmp.S new file mode 100644 index 000000000..e4d11b165 --- /dev/null +++ b/libc/sysdeps/linux/aarch64/__longjmp.S @@ -0,0 +1,107 @@ +/* Copyright (C) 1997-2016 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> + +/* __longjmp(jmpbuf, val) */ + +ENTRY (__longjmp) + cfi_def_cfa(x0, 0) + cfi_offset(x19, JB_X19<<3) + cfi_offset(x20, JB_X20<<3) + cfi_offset(x21, JB_X21<<3) + cfi_offset(x22, JB_X22<<3) + cfi_offset(x23, JB_X23<<3) + cfi_offset(x24, JB_X24<<3) + cfi_offset(x25, JB_X25<<3) + cfi_offset(x26, JB_X26<<3) + cfi_offset(x27, JB_X27<<3) + cfi_offset(x28, JB_X28<<3) + cfi_offset(x29, JB_X29<<3) + cfi_offset(x30, JB_LR<<3) + + cfi_offset( d8, JB_D8<<3) + cfi_offset( d9, JB_D9<<3) + cfi_offset(d10, JB_D10<<3) + cfi_offset(d11, JB_D11<<3) + cfi_offset(d12, JB_D12<<3) + cfi_offset(d13, JB_D13<<3) + cfi_offset(d14, JB_D14<<3) + cfi_offset(d15, JB_D15<<3) + + ldp x19, x20, [x0, #JB_X19<<3] + ldp x21, x22, [x0, #JB_X21<<3] + ldp x23, x24, [x0, #JB_X23<<3] + ldp x25, x26, [x0, #JB_X25<<3] + ldp x27, x28, [x0, #JB_X27<<3] + ldp x29, x30, [x0, #JB_X29<<3] + + /* longjmp probe takes 3 arguments, address of jump buffer as + first argument (8@x0), return value as second argument (-4@x1), + and target address (8@x30), respectively. */ + //LIBC_PROBE (longjmp, 3, 8@x0, -4@x1, 8@x30) + ldp d8, d9, [x0, #JB_D8<<3] + ldp d10, d11, [x0, #JB_D10<<3] + ldp d12, d13, [x0, #JB_D12<<3] + ldp d14, d15, [x0, #JB_D14<<3] + + /* Originally this was implemented with a series of + .cfi_restore() directives. + + The theory was that cfi_restore should revert to previous + frame value is the same as the current value. In practice + this doesn't work, even after cfi_restore() gdb continues + to try to recover a previous frame value offset from x0, + which gets stuffed after a few more instructions. The + cfi_same_value() mechanism appears to work fine. */ + + cfi_same_value(x19) + cfi_same_value(x20) + cfi_same_value(x21) + cfi_same_value(x22) + cfi_same_value(x23) + cfi_same_value(x24) + cfi_same_value(x25) + cfi_same_value(x26) + cfi_same_value(x27) + cfi_same_value(x28) + cfi_same_value(x29) + cfi_same_value(x30) + cfi_same_value(d8) + cfi_same_value(d9) + cfi_same_value(d10) + cfi_same_value(d11) + cfi_same_value(d12) + cfi_same_value(d13) + cfi_same_value(d14) + cfi_same_value(d15) + ldr x5, [x0, #JB_SP<<3] + mov sp, x5 + + /* longjmp_target probe takes 3 arguments, address of jump buffer + as first argument (8@x0), return value as second argument (-4@x1), + and target address (8@x30), respectively. */ + //LIBC_PROBE (longjmp_target, 3, 8@x0, -4@x1, 8@x30) + cmp x1, #0 + mov x0, #1 + csel x0, x1, x0, ne + /* Use br instead of ret because ret is guaranteed to mispredict */ + br x30 +END (__longjmp) +libc_hidden_def(__longjmp) |