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
|
/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* Code to prepare detour buffer for optprobes in Kernel.
*
* Copyright 2017, Anju T, IBM Corp.
*/
#include <asm/ppc_asm.h>
#include <asm/ptrace.h>
#include <asm/asm-offsets.h>
#define OPT_SLOT_SIZE 65536
.balign 4
/*
* Reserve an area to allocate slots for detour buffer.
* This is part of .text section (rather than vmalloc area)
* as this needs to be within 32MB of the probed address.
*/
.global optinsn_slot
optinsn_slot:
.space OPT_SLOT_SIZE
/*
* Optprobe template:
* This template gets copied into one of the slots in optinsn_slot
* and gets fixed up with real optprobe structures et al.
*/
.global optprobe_template_entry
optprobe_template_entry:
/* Create an in-memory pt_regs */
stdu r1,-INT_FRAME_SIZE(r1)
SAVE_GPR(0,r1)
/* Save the previous SP into stack */
addi r0,r1,INT_FRAME_SIZE
std r0,GPR1(r1)
SAVE_10GPRS(2,r1)
SAVE_10GPRS(12,r1)
SAVE_10GPRS(22,r1)
/* Save SPRS */
mfmsr r5
std r5,_MSR(r1)
li r5,0x700
std r5,_TRAP(r1)
li r5,0
std r5,ORIG_GPR3(r1)
std r5,RESULT(r1)
mfctr r5
std r5,_CTR(r1)
mflr r5
std r5,_LINK(r1)
mfspr r5,SPRN_XER
std r5,_XER(r1)
mfcr r5
std r5,_CCR(r1)
lbz r5,PACAIRQSOFTMASK(r13)
std r5,SOFTE(r1)
/*
* We may get here from a module, so load the kernel TOC in r2.
* The original TOC gets restored when pt_regs is restored
* further below.
*/
ld r2,PACATOC(r13)
.global optprobe_template_op_address
optprobe_template_op_address:
/*
* Parameters to optimized_callback():
* 1. optimized_kprobe structure in r3
*/
nop
nop
nop
nop
nop
/* 2. pt_regs pointer in r4 */
addi r4,r1,STACK_FRAME_OVERHEAD
.global optprobe_template_call_handler
optprobe_template_call_handler:
/* Branch to optimized_callback() */
nop
/*
* Parameters for instruction emulation:
* 1. Pass SP in register r3.
*/
addi r3,r1,STACK_FRAME_OVERHEAD
.global optprobe_template_insn
optprobe_template_insn:
/* 2, Pass instruction to be emulated in r4 */
nop
nop
nop
nop
nop
.global optprobe_template_call_emulate
optprobe_template_call_emulate:
/* Branch to emulate_step() */
nop
/*
* All done.
* Now, restore the registers...
*/
ld r5,_MSR(r1)
mtmsr r5
ld r5,_CTR(r1)
mtctr r5
ld r5,_LINK(r1)
mtlr r5
ld r5,_XER(r1)
mtxer r5
ld r5,_CCR(r1)
mtcr r5
REST_GPR(0,r1)
REST_10GPRS(2,r1)
REST_10GPRS(12,r1)
REST_10GPRS(22,r1)
/* Restore the previous SP */
addi r1,r1,INT_FRAME_SIZE
.global optprobe_template_ret
optprobe_template_ret:
/* ... and jump back from trampoline */
nop
.global optprobe_template_end
optprobe_template_end:
|
