1/* Copyright (C) 1997-2022 Free Software Foundation, Inc. 2 3 This file is part of the GNU C Library. 4 5 The GNU C Library is free software; you can redistribute it and/or 6 modify it under the terms of the GNU Lesser General Public License as 7 published by the Free Software Foundation; either version 2.1 of the 8 License, or (at your option) any later version. 9 10 The GNU C Library is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 Lesser General Public License for more details. 14 15 You should have received a copy of the GNU Lesser General Public 16 License along with the GNU C Library. If not, see 17 <https://www.gnu.org/licenses/>. */ 18 19#include <sysdep.h> 20#include <jmpbuf-offsets.h> 21#include <stap-probe.h> 22 23/* __longjmp(jmpbuf, val) */ 24 25ENTRY (__longjmp) 26 cfi_def_cfa(x0, 0) 27 cfi_offset(x19, JB_X19<<3) 28 cfi_offset(x20, JB_X20<<3) 29 cfi_offset(x21, JB_X21<<3) 30 cfi_offset(x22, JB_X22<<3) 31 cfi_offset(x23, JB_X23<<3) 32 cfi_offset(x24, JB_X24<<3) 33 cfi_offset(x25, JB_X25<<3) 34 cfi_offset(x26, JB_X26<<3) 35 cfi_offset(x27, JB_X27<<3) 36 cfi_offset(x28, JB_X28<<3) 37 cfi_offset(x29, JB_X29<<3) 38 cfi_offset(x30, JB_LR<<3) 39 40 cfi_offset( d8, JB_D8<<3) 41 cfi_offset( d9, JB_D9<<3) 42 cfi_offset(d10, JB_D10<<3) 43 cfi_offset(d11, JB_D11<<3) 44 cfi_offset(d12, JB_D12<<3) 45 cfi_offset(d13, JB_D13<<3) 46 cfi_offset(d14, JB_D14<<3) 47 cfi_offset(d15, JB_D15<<3) 48 49 PTR_ARG (0) 50 51 ldp x19, x20, [x0, #JB_X19<<3] 52 ldp x21, x22, [x0, #JB_X21<<3] 53 ldp x23, x24, [x0, #JB_X23<<3] 54 ldp x25, x26, [x0, #JB_X25<<3] 55 ldp x27, x28, [x0, #JB_X27<<3] 56#ifdef PTR_DEMANGLE 57 ldp x29, x4, [x0, #JB_X29<<3] 58 PTR_DEMANGLE (30, 4, 3, 2) 59#else 60 ldp x29, x30, [x0, #JB_X29<<3] 61#endif 62 /* longjmp probe takes 3 arguments, address of jump buffer as 63 first argument (8@x0), return value as second argument (-4@x1), 64 and target address (8@x30), respectively. */ 65 LIBC_PROBE (longjmp, 3, 8@x0, -4@x1, 8@x30) 66 ldp d8, d9, [x0, #JB_D8<<3] 67 ldp d10, d11, [x0, #JB_D10<<3] 68 ldp d12, d13, [x0, #JB_D12<<3] 69 ldp d14, d15, [x0, #JB_D14<<3] 70 71 /* Originally this was implemented with a series of 72 .cfi_restore() directives. 73 74 The theory was that cfi_restore should revert to previous 75 frame value is the same as the current value. In practice 76 this doesn't work, even after cfi_restore() gdb continues 77 to try to recover a previous frame value offset from x0, 78 which gets stuffed after a few more instructions. The 79 cfi_same_value() mechanism appears to work fine. */ 80 81 cfi_same_value(x19) 82 cfi_same_value(x20) 83 cfi_same_value(x21) 84 cfi_same_value(x22) 85 cfi_same_value(x23) 86 cfi_same_value(x24) 87 cfi_same_value(x25) 88 cfi_same_value(x26) 89 cfi_same_value(x27) 90 cfi_same_value(x28) 91 cfi_same_value(x29) 92 cfi_same_value(x30) 93 cfi_same_value(d8) 94 cfi_same_value(d9) 95 cfi_same_value(d10) 96 cfi_same_value(d11) 97 cfi_same_value(d12) 98 cfi_same_value(d13) 99 cfi_same_value(d14) 100 cfi_same_value(d15) 101#ifdef PTR_DEMANGLE 102 ldr x4, [x0, #JB_SP<<3] 103 PTR_DEMANGLE (5, 4, 3, 2) 104#else 105 ldr x5, [x0, #JB_SP<<3] 106#endif 107 mov sp, x5 108 109 /* longjmp_target probe takes 3 arguments, address of jump buffer 110 as first argument (8@x0), return value as second argument (-4@x1), 111 and target address (8@x30), respectively. */ 112 LIBC_PROBE (longjmp_target, 3, 8@x0, -4@x1, 8@x30) 113 cmp x1, #0 114 mov x0, #1 115 csel x0, x1, x0, ne 116 /* Use br instead of ret because ret is guaranteed to mispredict */ 117 br x30 118END (__longjmp) 119