4 * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
5 * Copyright (C) 2015 Huawei Inc.
8 #include <bpf/libbpf.h>
12 #include "bpf-loader.h"
13 #include "probe-event.h"
14 #include "probe-finder.h" // for MAX_PROBES
15 #include "llvm-utils.h"
17 #define DEFINE_PRINT_FN(name, level) \
18 static int libbpf_##name(const char *fmt, ...) \
23 va_start(args, fmt); \
24 ret = veprintf(level, verbose, pr_fmt(fmt), args);\
29 DEFINE_PRINT_FN(warning
, 0)
30 DEFINE_PRINT_FN(info
, 0)
31 DEFINE_PRINT_FN(debug
, 1)
33 struct bpf_prog_priv
{
34 struct perf_probe_event pev
;
37 struct bpf_object
*bpf__prepare_load(const char *filename
, bool source
)
39 struct bpf_object
*obj
;
40 static bool libbpf_initialized
;
42 if (!libbpf_initialized
) {
43 libbpf_set_print(libbpf_warning
,
46 libbpf_initialized
= true;
54 err
= llvm__compile_bpf(filename
, &obj_buf
, &obj_buf_sz
);
57 obj
= bpf_object__open_buffer(obj_buf
, obj_buf_sz
, filename
);
60 obj
= bpf_object__open(filename
);
63 pr_debug("bpf: failed to load %s\n", filename
);
64 return ERR_PTR(-EINVAL
);
72 struct bpf_object
*obj
, *tmp
;
74 bpf_object__for_each_safe(obj
, tmp
) {
76 bpf_object__close(obj
);
81 bpf_prog_priv__clear(struct bpf_program
*prog __maybe_unused
,
84 struct bpf_prog_priv
*priv
= _priv
;
86 cleanup_perf_probe_events(&priv
->pev
, 1);
91 config_bpf_program(struct bpf_program
*prog
)
93 struct perf_probe_event
*pev
= NULL
;
94 struct bpf_prog_priv
*priv
= NULL
;
95 const char *config_str
;
98 config_str
= bpf_program__title(prog
, false);
100 pr_debug("bpf: unable to get title for program\n");
104 priv
= calloc(sizeof(*priv
), 1);
106 pr_debug("bpf: failed to alloc priv\n");
111 pr_debug("bpf: config program '%s'\n", config_str
);
112 err
= parse_perf_probe_command(config_str
, pev
);
114 pr_debug("bpf: '%s' is not a valid config string\n",
120 if (pev
->group
&& strcmp(pev
->group
, PERF_BPF_PROBE_GROUP
)) {
121 pr_debug("bpf: '%s': group for event is set and not '%s'.\n",
122 config_str
, PERF_BPF_PROBE_GROUP
);
125 } else if (!pev
->group
)
126 pev
->group
= strdup(PERF_BPF_PROBE_GROUP
);
129 pr_debug("bpf: strdup failed\n");
135 pr_debug("bpf: '%s': event name is missing\n",
140 pr_debug("bpf: config '%s' is ok\n", config_str
);
142 err
= bpf_program__set_private(prog
, priv
, bpf_prog_priv__clear
);
144 pr_debug("Failed to set priv for program '%s'\n", config_str
);
152 clear_perf_probe_event(pev
);
157 static int bpf__prepare_probe(void)
160 static bool initialized
= false;
163 * Make err static, so if init failed the first, bpf__prepare_probe()
164 * fails each time without calling init_probe_symbol_maps multiple
171 err
= init_probe_symbol_maps(false);
173 pr_debug("Failed to init_probe_symbol_maps\n");
174 probe_conf
.max_probes
= MAX_PROBES
;
178 int bpf__probe(struct bpf_object
*obj
)
181 struct bpf_program
*prog
;
182 struct bpf_prog_priv
*priv
;
183 struct perf_probe_event
*pev
;
185 err
= bpf__prepare_probe();
187 pr_debug("bpf__prepare_probe failed\n");
191 bpf_object__for_each_program(prog
, obj
) {
192 err
= config_bpf_program(prog
);
196 err
= bpf_program__get_private(prog
, (void **)&priv
);
201 err
= convert_perf_probe_events(pev
, 1);
203 pr_debug("bpf_probe: failed to convert perf probe events");
207 err
= apply_perf_probe_events(pev
, 1);
209 pr_debug("bpf_probe: failed to apply perf probe events");
214 return err
< 0 ? err
: 0;
217 #define EVENTS_WRITE_BUFSIZE 4096
218 int bpf__unprobe(struct bpf_object
*obj
)
221 struct bpf_program
*prog
;
222 struct bpf_prog_priv
*priv
;
224 bpf_object__for_each_program(prog
, obj
) {
227 err
= bpf_program__get_private(prog
, (void **)&priv
);
231 for (i
= 0; i
< priv
->pev
.ntevs
; i
++) {
232 struct probe_trace_event
*tev
= &priv
->pev
.tevs
[i
];
233 char name_buf
[EVENTS_WRITE_BUFSIZE
];
234 struct strfilter
*delfilter
;
236 snprintf(name_buf
, EVENTS_WRITE_BUFSIZE
,
237 "%s:%s", tev
->group
, tev
->event
);
238 name_buf
[EVENTS_WRITE_BUFSIZE
- 1] = '\0';
240 delfilter
= strfilter__new(name_buf
, NULL
);
242 pr_debug("Failed to create filter for unprobing\n");
247 err
= del_perf_probe_events(delfilter
);
248 strfilter__delete(delfilter
);
250 pr_debug("Failed to delete %s\n", name_buf
);
259 int bpf__load(struct bpf_object
*obj
)
263 err
= bpf_object__load(obj
);
265 pr_debug("bpf: load objects failed\n");
271 int bpf__foreach_tev(struct bpf_object
*obj
,
272 bpf_prog_iter_callback_t func
,
275 struct bpf_program
*prog
;
278 bpf_object__for_each_program(prog
, obj
) {
279 struct probe_trace_event
*tev
;
280 struct perf_probe_event
*pev
;
281 struct bpf_prog_priv
*priv
;
284 err
= bpf_program__get_private(prog
,
287 pr_debug("bpf: failed to get private field\n");
292 for (i
= 0; i
< pev
->ntevs
; i
++) {
295 fd
= bpf_program__fd(prog
);
297 pr_debug("bpf: failed to get file descriptor\n");
301 err
= (*func
)(tev
, fd
, arg
);
303 pr_debug("bpf: call back failed, stop iterate\n");
311 #define bpf__strerror_head(err, buf, size) \
312 char sbuf[STRERR_BUFSIZE], *emsg;\
317 emsg = strerror_r(err, sbuf, sizeof(sbuf));\
320 scnprintf(buf, size, "%s", emsg);\
323 #define bpf__strerror_entry(val, fmt...)\
325 scnprintf(buf, size, fmt);\
329 #define bpf__strerror_end(buf, size)\
331 buf[size - 1] = '\0';
333 int bpf__strerror_probe(struct bpf_object
*obj __maybe_unused
,
334 int err
, char *buf
, size_t size
)
336 bpf__strerror_head(err
, buf
, size
);
337 bpf__strerror_entry(EEXIST
, "Probe point exist. Try use 'perf probe -d \"*\"'");
338 bpf__strerror_entry(EPERM
, "You need to be root, and /proc/sys/kernel/kptr_restrict should be 0\n");
339 bpf__strerror_entry(ENOENT
, "You need to check probing points in BPF file\n");
340 bpf__strerror_end(buf
, size
);
344 int bpf__strerror_load(struct bpf_object
*obj __maybe_unused
,
345 int err
, char *buf
, size_t size
)
347 bpf__strerror_head(err
, buf
, size
);
348 bpf__strerror_entry(EINVAL
, "%s: Are you root and runing a CONFIG_BPF_SYSCALL kernel?",
350 bpf__strerror_end(buf
, size
);