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
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
|
// SPDX-License-Identifier: GPL-2.0
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/sched/task_stack.h>
#include <linux/perf_event.h>
#include <linux/bug.h>
#include <linux/stddef.h>
#include <asm/perf_regs.h>
#include <asm/ptrace.h>
#ifdef CONFIG_X86_32
#define PERF_REG_X86_MAX PERF_REG_X86_32_MAX
#else
#define PERF_REG_X86_MAX PERF_REG_X86_64_MAX
#endif
#define PT_REGS_OFFSET(id, r) [id] = offsetof(struct pt_regs, r)
static unsigned int pt_regs_offset[PERF_REG_X86_MAX] = {
PT_REGS_OFFSET(PERF_REG_X86_AX, ax),
PT_REGS_OFFSET(PERF_REG_X86_BX, bx),
PT_REGS_OFFSET(PERF_REG_X86_CX, cx),
PT_REGS_OFFSET(PERF_REG_X86_DX, dx),
PT_REGS_OFFSET(PERF_REG_X86_SI, si),
PT_REGS_OFFSET(PERF_REG_X86_DI, di),
PT_REGS_OFFSET(PERF_REG_X86_BP, bp),
PT_REGS_OFFSET(PERF_REG_X86_SP, sp),
PT_REGS_OFFSET(PERF_REG_X86_IP, ip),
PT_REGS_OFFSET(PERF_REG_X86_FLAGS, flags),
PT_REGS_OFFSET(PERF_REG_X86_CS, cs),
PT_REGS_OFFSET(PERF_REG_X86_SS, ss),
#ifdef CONFIG_X86_32
PT_REGS_OFFSET(PERF_REG_X86_DS, ds),
PT_REGS_OFFSET(PERF_REG_X86_ES, es),
PT_REGS_OFFSET(PERF_REG_X86_FS, fs),
PT_REGS_OFFSET(PERF_REG_X86_GS, gs),
#else
/*
* The pt_regs struct does not store
* ds, es, fs, gs in 64 bit mode.
*/
(unsigned int) -1,
(unsigned int) -1,
(unsigned int) -1,
(unsigned int) -1,
#endif
#ifdef CONFIG_X86_64
PT_REGS_OFFSET(PERF_REG_X86_R8, r8),
PT_REGS_OFFSET(PERF_REG_X86_R9, r9),
PT_REGS_OFFSET(PERF_REG_X86_R10, r10),
PT_REGS_OFFSET(PERF_REG_X86_R11, r11),
PT_REGS_OFFSET(PERF_REG_X86_R12, r12),
PT_REGS_OFFSET(PERF_REG_X86_R13, r13),
PT_REGS_OFFSET(PERF_REG_X86_R14, r14),
PT_REGS_OFFSET(PERF_REG_X86_R15, r15),
#endif
};
u64 perf_reg_value(struct pt_regs *regs, int idx)
{
if (WARN_ON_ONCE(idx >= ARRAY_SIZE(pt_regs_offset)))
return 0;
return regs_get_register(regs, pt_regs_offset[idx]);
}
#define REG_RESERVED (~((1ULL << PERF_REG_X86_MAX) - 1ULL))
#ifdef CONFIG_X86_32
int perf_reg_validate(u64 mask)
{
if (!mask || mask & REG_RESERVED)
return -EINVAL;
return 0;
}
u64 perf_reg_abi(struct task_struct *task)
{
return PERF_SAMPLE_REGS_ABI_32;
}
void perf_get_regs_user(struct perf_regs *regs_user,
struct pt_regs *regs,
struct pt_regs *regs_user_copy)
{
regs_user->regs = task_pt_regs(current);
regs_user->abi = perf_reg_abi(current);
}
#else /* CONFIG_X86_64 */
#define REG_NOSUPPORT ((1ULL << PERF_REG_X86_DS) | \
(1ULL << PERF_REG_X86_ES) | \
(1ULL << PERF_REG_X86_FS) | \
(1ULL << PERF_REG_X86_GS))
int perf_reg_validate(u64 mask)
{
if (!mask || mask & REG_RESERVED)
return -EINVAL;
if (mask & REG_NOSUPPORT)
return -EINVAL;
return 0;
}
u64 perf_reg_abi(struct task_struct *task)
{
if (test_tsk_thread_flag(task, TIF_IA32))
return PERF_SAMPLE_REGS_ABI_32;
else
return PERF_SAMPLE_REGS_ABI_64;
}
void perf_get_regs_user(struct perf_regs *regs_user,
struct pt_regs *regs,
struct pt_regs *regs_user_copy)
{
struct pt_regs *user_regs = task_pt_regs(current);
/*
* If we're in an NMI that interrupted task_pt_regs setup, then
* we can't sample user regs at all. This check isn't really
* sufficient, though, as we could be in an NMI inside an interrupt
* that happened during task_pt_regs setup.
*/
if (regs->sp > (unsigned long)&user_regs->r11 &&
regs->sp <= (unsigned long)(user_regs + 1)) {
regs_user->abi = PERF_SAMPLE_REGS_ABI_NONE;
regs_user->regs = NULL;
return;
}
/*
* These registers are always saved on 64-bit syscall entry.
* On 32-bit entry points, they are saved too except r8..r11.
*/
regs_user_copy->ip = user_regs->ip;
regs_user_copy->ax = user_regs->ax;
regs_user_copy->cx = user_regs->cx;
regs_user_copy->dx = user_regs->dx;
regs_user_copy->si = user_regs->si;
regs_user_copy->di = user_regs->di;
regs_user_copy->r8 = user_regs->r8;
regs_user_copy->r9 = user_regs->r9;
regs_user_copy->r10 = user_regs->r10;
regs_user_copy->r11 = user_regs->r11;
regs_user_copy->orig_ax = user_regs->orig_ax;
regs_user_copy->flags = user_regs->flags;
regs_user_copy->sp = user_regs->sp;
regs_user_copy->cs = user_regs->cs;
regs_user_copy->ss = user_regs->ss;
/*
* Most system calls don't save these registers, don't report them.
*/
regs_user_copy->bx = -1;
regs_user_copy->bp = -1;
regs_user_copy->r12 = -1;
regs_user_copy->r13 = -1;
regs_user_copy->r14 = -1;
regs_user_copy->r15 = -1;
/*
* For this to be at all useful, we need a reasonable guess for
* the ABI. Be careful: we're in NMI context, and we're
* considering current to be the current task, so we should
* be careful not to look at any other percpu variables that might
* change during context switches.
*/
regs_user->abi = user_64bit_mode(user_regs) ?
PERF_SAMPLE_REGS_ABI_64 : PERF_SAMPLE_REGS_ABI_32;
regs_user->regs = regs_user_copy;
}
#endif /* CONFIG_X86_32 */
|
