about summary refs log tree commit diff
path: root/sysdeps/aarch64/__longjmp.S
blob: 7b6add751e6bd96bd08599d0ab3f65ffe572a768 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
/* Copyright (C) 1997-2024 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
   <https://www.gnu.org/licenses/>.  */

#include <sysdep.h>
#include <pointer_guard.h>
#include <jmpbuf-offsets.h>
#include <stap-probe.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)

	PTR_ARG (0)

#if IS_IN(libc)
	/* Disable ZA state of SME in libc.a and libc.so, but not in ld.so.  */
# if HAVE_AARCH64_PAC_RET
	PACIASP
	cfi_window_save
# endif
	stp	x29, x30, [sp, -16]!
	cfi_adjust_cfa_offset (16)
	cfi_rel_offset (x29, 0)
	cfi_rel_offset (x30, 8)
	mov	x29, sp
	bl	__libc_arm_za_disable
	ldp	x29, x30, [sp], 16
	cfi_adjust_cfa_offset (-16)
	cfi_restore (x29)
	cfi_restore (x30)
# if HAVE_AARCH64_PAC_RET
	AUTIASP
	cfi_window_save
# endif
#endif

	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]
#ifdef PTR_DEMANGLE
	ldp	x29,  x4, [x0, #JB_X29<<3]
	PTR_DEMANGLE (30, 4, 3, 2)
#else
	ldp	x29, x30, [x0, #JB_X29<<3]
#endif
	/* 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)
#ifdef PTR_DEMANGLE
	ldr	x4, [x0, #JB_SP<<3]
	PTR_DEMANGLE (5, 4, 3, 2)
#else
	ldr	x5, [x0, #JB_SP<<3]
#endif
	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)