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
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
|
/* SPDX-License-Identifier: GPL-2.0 */
#include <stdlib.h>
#include <bpf/bpf.h>
#include <linux/err.h>
#include <internal/xyarray.h>
#include "util/debug.h"
#include "util/evsel.h"
#include "util/bpf-filter.h"
#include <util/bpf-filter-flex.h>
#include <util/bpf-filter-bison.h>
#include "bpf_skel/sample-filter.h"
#include "bpf_skel/sample_filter.skel.h"
#define FD(e, x, y) (*(int *)xyarray__entry(e->core.fd, x, y))
#define __PERF_SAMPLE_TYPE(st, opt) { st, #st, opt }
#define PERF_SAMPLE_TYPE(_st, opt) __PERF_SAMPLE_TYPE(PERF_SAMPLE_##_st, opt)
static const struct perf_sample_info {
u64 type;
const char *name;
const char *option;
} sample_table[] = {
/* default sample flags */
PERF_SAMPLE_TYPE(IP, NULL),
PERF_SAMPLE_TYPE(TID, NULL),
PERF_SAMPLE_TYPE(PERIOD, NULL),
/* flags mostly set by default, but still have options */
PERF_SAMPLE_TYPE(ID, "--sample-identifier"),
PERF_SAMPLE_TYPE(CPU, "--sample-cpu"),
PERF_SAMPLE_TYPE(TIME, "-T"),
/* optional sample flags */
PERF_SAMPLE_TYPE(ADDR, "-d"),
PERF_SAMPLE_TYPE(DATA_SRC, "-d"),
PERF_SAMPLE_TYPE(PHYS_ADDR, "--phys-data"),
PERF_SAMPLE_TYPE(WEIGHT, "-W"),
PERF_SAMPLE_TYPE(WEIGHT_STRUCT, "-W"),
PERF_SAMPLE_TYPE(TRANSACTION, "--transaction"),
PERF_SAMPLE_TYPE(CODE_PAGE_SIZE, "--code-page-size"),
PERF_SAMPLE_TYPE(DATA_PAGE_SIZE, "--data-page-size"),
};
static const struct perf_sample_info *get_sample_info(u64 flags)
{
size_t i;
for (i = 0; i < ARRAY_SIZE(sample_table); i++) {
if (sample_table[i].type == flags)
return &sample_table[i];
}
return NULL;
}
static int check_sample_flags(struct evsel *evsel, struct perf_bpf_filter_expr *expr)
{
const struct perf_sample_info *info;
if (evsel->core.attr.sample_type & expr->sample_flags)
return 0;
if (expr->op == PBF_OP_GROUP_BEGIN) {
struct perf_bpf_filter_expr *group;
list_for_each_entry(group, &expr->groups, list) {
if (check_sample_flags(evsel, group) < 0)
return -1;
}
return 0;
}
info = get_sample_info(expr->sample_flags);
if (info == NULL) {
pr_err("Error: %s event does not have sample flags %lx\n",
evsel__name(evsel), expr->sample_flags);
return -1;
}
pr_err("Error: %s event does not have %s\n", evsel__name(evsel), info->name);
if (info->option)
pr_err(" Hint: please add %s option to perf record\n", info->option);
return -1;
}
int perf_bpf_filter__prepare(struct evsel *evsel)
{
int i, x, y, fd;
struct sample_filter_bpf *skel;
struct bpf_program *prog;
struct bpf_link *link;
struct perf_bpf_filter_expr *expr;
skel = sample_filter_bpf__open_and_load();
if (!skel) {
pr_err("Failed to load perf sample-filter BPF skeleton\n");
return -1;
}
i = 0;
fd = bpf_map__fd(skel->maps.filters);
list_for_each_entry(expr, &evsel->bpf_filters, list) {
struct perf_bpf_filter_entry entry = {
.op = expr->op,
.part = expr->part,
.flags = expr->sample_flags,
.value = expr->val,
};
if (check_sample_flags(evsel, expr) < 0)
return -1;
bpf_map_update_elem(fd, &i, &entry, BPF_ANY);
i++;
if (expr->op == PBF_OP_GROUP_BEGIN) {
struct perf_bpf_filter_expr *group;
list_for_each_entry(group, &expr->groups, list) {
struct perf_bpf_filter_entry group_entry = {
.op = group->op,
.part = group->part,
.flags = group->sample_flags,
.value = group->val,
};
bpf_map_update_elem(fd, &i, &group_entry, BPF_ANY);
i++;
}
memset(&entry, 0, sizeof(entry));
entry.op = PBF_OP_GROUP_END;
bpf_map_update_elem(fd, &i, &entry, BPF_ANY);
i++;
}
}
if (i > MAX_FILTERS) {
pr_err("Too many filters: %d (max = %d)\n", i, MAX_FILTERS);
return -1;
}
prog = skel->progs.perf_sample_filter;
for (x = 0; x < xyarray__max_x(evsel->core.fd); x++) {
for (y = 0; y < xyarray__max_y(evsel->core.fd); y++) {
link = bpf_program__attach_perf_event(prog, FD(evsel, x, y));
if (IS_ERR(link)) {
pr_err("Failed to attach perf sample-filter program\n");
return PTR_ERR(link);
}
}
}
evsel->bpf_skel = skel;
return 0;
}
int perf_bpf_filter__destroy(struct evsel *evsel)
{
struct perf_bpf_filter_expr *expr, *tmp;
list_for_each_entry_safe(expr, tmp, &evsel->bpf_filters, list) {
list_del(&expr->list);
free(expr);
}
sample_filter_bpf__destroy(evsel->bpf_skel);
return 0;
}
u64 perf_bpf_filter__lost_count(struct evsel *evsel)
{
struct sample_filter_bpf *skel = evsel->bpf_skel;
return skel ? skel->bss->dropped : 0;
}
struct perf_bpf_filter_expr *perf_bpf_filter_expr__new(unsigned long sample_flags, int part,
enum perf_bpf_filter_op op,
unsigned long val)
{
struct perf_bpf_filter_expr *expr;
expr = malloc(sizeof(*expr));
if (expr != NULL) {
expr->sample_flags = sample_flags;
expr->part = part;
expr->op = op;
expr->val = val;
INIT_LIST_HEAD(&expr->groups);
}
return expr;
}
int perf_bpf_filter__parse(struct list_head *expr_head, const char *str)
{
YY_BUFFER_STATE buffer;
int ret;
buffer = perf_bpf_filter__scan_string(str);
ret = perf_bpf_filter_parse(expr_head);
perf_bpf_filter__flush_buffer(buffer);
perf_bpf_filter__delete_buffer(buffer);
perf_bpf_filter_lex_destroy();
return ret;
}
|
