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
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
|
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* linux/arch/unicore32/lib/backtrace.S
*
* Code specific to PKUnity SoC and UniCore ISA
*
* Copyright (C) 2001-2010 GUAN Xue-tao
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
.text
@ fp is 0 or stack frame
#define frame v4
#define sv_fp v5
#define sv_pc v6
#define offset v8
ENTRY(__backtrace)
mov r0, fp
ENTRY(c_backtrace)
#if !defined(CONFIG_FRAME_POINTER) || !defined(CONFIG_PRINTK)
mov pc, lr
ENDPROC(__backtrace)
ENDPROC(c_backtrace)
#else
stm.w (v4 - v8, lr), [sp-] @ Save an extra register
@ so we have a location...
mov.a frame, r0 @ if frame pointer is zero
beq no_frame @ we have no stack frames
1: stm.w (pc), [sp-] @ calculate offset of PC stored
ldw.w r0, [sp]+, #4 @ by stmfd for this CPU
adr r1, 1b
sub offset, r0, r1
/*
* Stack frame layout:
* optionally saved caller registers (r4 - r10)
* saved fp
* saved sp
* saved lr
* frame => saved pc
* optionally saved arguments (r0 - r3)
* saved sp => <next word>
*
* Functions start with the following code sequence:
* mov ip, sp
* stm.w (r0 - r3), [sp-] (optional)
* corrected pc => stm.w sp, (..., fp, ip, lr, pc)
*/
for_each_frame:
1001: ldw sv_pc, [frame+], #0 @ get saved pc
1002: ldw sv_fp, [frame+], #-12 @ get saved fp
sub sv_pc, sv_pc, offset @ Correct PC for prefetching
1003: ldw r2, [sv_pc+], #-4 @ if stmfd sp, {args} exists,
ldw r3, .Ldsi+4 @ adjust saved 'pc' back one
cxor.a r3, r2 >> #14 @ instruction
beq 201f
sub r0, sv_pc, #4 @ allow for mov
b 202f
201:
sub r0, sv_pc, #8 @ allow for mov + stmia
202:
ldw r1, [frame+], #-4 @ get saved lr
mov r2, frame
b.l dump_backtrace_entry
ldw r1, [sv_pc+], #-4 @ if stmfd sp, {args} exists,
ldw r3, .Ldsi+4
cxor.a r3, r1 >> #14
bne 1004f
ldw r0, [frame+], #-8 @ get sp
sub r0, r0, #4 @ point at the last arg
b.l .Ldumpstm @ dump saved registers
1004: ldw r1, [sv_pc+], #0 @ if stmfd {, fp, ip, lr, pc}
ldw r3, .Ldsi @ instruction exists,
cxor.a r3, r1 >> #14
bne 201f
sub r0, frame, #16
b.l .Ldumpstm @ dump saved registers
201:
cxor.a sv_fp, #0 @ zero saved fp means
beq no_frame @ no further frames
csub.a sv_fp, frame @ next frame must be
mov frame, sv_fp @ above the current frame
bua for_each_frame
1006: adr r0, .Lbad
mov r1, frame
b.l printk
no_frame: ldm.w (v4 - v8, pc), [sp]+
ENDPROC(__backtrace)
ENDPROC(c_backtrace)
.pushsection __ex_table,"a"
.align 3
.long 1001b, 1006b
.long 1002b, 1006b
.long 1003b, 1006b
.long 1004b, 1006b
.popsection
#define instr v4
#define reg v5
#define stack v6
.Ldumpstm: stm.w (instr, reg, stack, v7, lr), [sp-]
mov stack, r0
mov instr, r1
mov reg, #14
mov v7, #0
1: mov r3, #1
csub.a reg, #8
bne 201f
sub reg, reg, #3
201:
cand.a instr, r3 << reg
beq 2f
add v7, v7, #1
cxor.a v7, #6
cmoveq v7, #1
cmoveq r1, #'\n'
cmovne r1, #' '
ldw.w r3, [stack]+, #-4
mov r2, reg
csub.a r2, #8
bsl 201f
sub r2, r2, #3
201:
cand.a instr, #0x40 @ if H is 1, high 16 regs
beq 201f
add r2, r2, #0x10 @ so r2 need add 16
201:
adr r0, .Lfp
b.l printk
2: sub.a reg, reg, #1
bns 1b
cxor.a v7, #0
beq 201f
adr r0, .Lcr
b.l printk
201: ldm.w (instr, reg, stack, v7, pc), [sp]+
.Lfp: .asciz "%cr%d:%08x"
.Lcr: .asciz "\n"
.Lbad: .asciz "Backtrace aborted due to bad frame pointer <%p>\n"
.align
.Ldsi: .word 0x92eec000 >> 14 @ stm.w sp, (... fp, ip, lr, pc)
.word 0x92e10000 >> 14 @ stm.w sp, ()
#endif
|
