1/* longjmp for ARM.
2 Copyright (C) 1997-2022 Free Software Foundation, Inc.
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
7 License as published by the Free Software Foundation; either
8 version 2.1 of the 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 <stap-probe.h>
21#include <bits/setjmp.h>
22#include <rtld-global-offsets.h>
23#include <arm-features.h>
24
25/* __longjmp(jmpbuf, val) */
26
27ENTRY (__longjmp)
28 mov ip, r0
29
30#ifdef CHECK_SP
31 ldr r4, [ip] /* jmpbuf's sp */
32 cfi_undefined (r4)
33#ifdef PTR_DEMANGLE
34 PTR_DEMANGLE (r4, r4, a3, a4)
35#endif
36 CHECK_SP (r4)
37#endif
38
39#ifdef PTR_DEMANGLE
40 ldr a4, [ip], #4
41 PTR_DEMANGLE (a4, a4, a3, r4)
42 cfi_undefined (r4)
43 ldr r4, [ip], #4
44 PTR_DEMANGLE2 (r4, r4, a3)
45#else
46 ldr a4, [ip], #4
47 ldr r4, [ip], #4
48 cfi_undefined (r4)
49#endif
50 /* longjmp probe expects longjmp first argument (4@r0), second
51 argument (-4@r1), and target address (4@r4), respectively. */
52 LIBC_PROBE (longjmp, 3, 4@r0, -4@r1, 4@r4)
53 mov sp, a4
54 mov lr, r4
55 ldmia ip!, JMP_BUF_REGLIST
56 cfi_restore (v1)
57 cfi_restore (v2)
58 cfi_restore (v3)
59 cfi_restore (v4)
60 cfi_restore (v5)
61 cfi_restore (v6)
62 cfi_restore (sl)
63 cfi_restore (fp)
64 cfi_restore (sp)
65 cfi_restore (lr)
66
67#if !defined ARM_ASSUME_NO_IWMMXT || defined __SOFTFP__
68# define NEED_HWCAP 1
69#endif
70
71#ifdef NEED_HWCAP
72# if IS_IN (rtld)
73 LDST_PCREL (ldr, a4, a3, \
74 C_SYMBOL_NAME(_rtld_local_ro) \
75 + RTLD_GLOBAL_RO_DL_HWCAP_OFFSET)
76# else
77# ifdef SHARED
78 LDR_GLOBAL (a4, a3, C_SYMBOL_NAME(_rtld_global_ro), \
79 RTLD_GLOBAL_RO_DL_HWCAP_OFFSET)
80# else
81 LDR_GLOBAL (a4, a3, C_SYMBOL_NAME(_dl_hwcap), 0)
82# endif
83# endif
84#endif
85
86#ifdef __SOFTFP__
87 tst a4, #HWCAP_ARM_VFP
88 beq .Lno_vfp
89#endif
90
91 /* Restore the VFP registers. */
92 /* Following instruction is vldmia ip!, {d8-d15}. */
93 ldc p11, cr8, [r12], #64
94.Lno_vfp:
95
96#ifndef ARM_ASSUME_NO_IWMMXT
97 tst a4, #HWCAP_ARM_IWMMXT
98 beq .Lno_iwmmxt
99
100 /* Restore the call-preserved iWMMXt registers. */
101 /* Following instructions are wldrd wr10, [ip], #8 (etc.) */
102 ldcl p1, cr10, [r12], #8
103 ldcl p1, cr11, [r12], #8
104 ldcl p1, cr12, [r12], #8
105 ldcl p1, cr13, [r12], #8
106 ldcl p1, cr14, [r12], #8
107 ldcl p1, cr15, [r12], #8
108.Lno_iwmmxt:
109#endif
110
111 /* longjmp_target probe expects longjmp first argument (4@r0), second
112 argument (-4@r1), and target address (4@r14), respectively. */
113 LIBC_PROBE (longjmp_target, 3, 4@r0, -4@r1, 4@r14)
114
115 movs r0, r1 /* get the return value in place */
116 it eq
117 moveq r0, #1 /* can't let setjmp() return zero! */
118
119 DO_RET(lr)
120
121END (__longjmp)
122

source code of glibc/sysdeps/arm/__longjmp.S