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);