blob: ba414c338b0b5bf250faafe427e94130ddae1b95 (
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
|
/* Dynamic loading of the libgcc unwinder. MIPS customization.
Copyright (C) 2020-2024 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/>. */
#ifndef _ARCH_UNWIND_LINK_H
#define _ARCH_UNWIND_LINK_H
#include <stdint.h>
#include <sys/syscall.h>
#define UNWIND_LINK_GETIP 1
#define UNWIND_LINK_FRAME_STATE_FOR 1
#define UNWIND_LINK_FRAME_ADJUSTMENT 1
#define UNWIND_LINK_EXTRA_FIELDS
#define UNWIND_LINK_EXTRA_INIT
/* MIPS fallback code handle a frame where its FDE can not be obtained
(for instance a signal frame) by reading the kernel allocated signal frame
and adding '2' to the value of 'sc_pc' [1]. The added value is used to
recognize an end of an EH region on mips16 [2].
The idea here is to adjust the obtained signal frame ADDR value and remove
the libgcc added value by checking if the previous frame is a signal frame
one.
[1] libgcc/config/mips/linux-unwind.h from gcc code.
[2] gcc/config/mips/mips.h from gcc code. */
static inline void *
unwind_arch_adjustment (void *prev, void *addr)
{
uint32_t *pc = (uint32_t *) prev;
if (pc == NULL)
return addr;
/* For MIPS16 or microMIPS frame libgcc makes no adjustment. */
if ((uintptr_t) pc & 0x3)
return addr;
/* The vDSO contains either
24021061 li v0, 0x1061 (rt_sigreturn)
0000000c syscall
or
24021017 li v0, 0x1017 (sigreturn)
0000000c syscall */
if (pc[1] != 0x0000000c)
return addr;
#if _MIPS_SIM == _ABIO32
if (pc[0] == (0x24020000 | __NR_sigreturn))
return (void *) ((uintptr_t) addr - 2);
#endif
if (pc[0] == (0x24020000 | __NR_rt_sigreturn))
return (void *) ((uintptr_t) addr - 2);
return addr;
}
#endif /* _ARCH_UNWIND_LINK_H */
|
