Commit | Line | Data |
---|---|---|
bcea3f96 | 1 | // SPDX-License-Identifier: GPL-2.0 |
413d37d1 | 2 | /* |
77b44d1b | 3 | * Kprobes-based tracing events |
413d37d1 MH |
4 | * |
5 | * Created by Masami Hiramatsu <mhiramat@redhat.com> | |
6 | * | |
413d37d1 | 7 | */ |
72576341 | 8 | #define pr_fmt(fmt) "trace_kprobe: " fmt |
413d37d1 | 9 | |
aef2feda | 10 | #include <linux/bpf-cgroup.h> |
17911ff3 | 11 | #include <linux/security.h> |
413d37d1 MH |
12 | #include <linux/module.h> |
13 | #include <linux/uaccess.h> | |
b2d09103 | 14 | #include <linux/rculist.h> |
540adea3 | 15 | #include <linux/error-injection.h> |
413d37d1 | 16 | |
970988e1 MH |
17 | #include <asm/setup.h> /* for COMMAND_LINE_SIZE */ |
18 | ||
6212dd29 | 19 | #include "trace_dynevent.h" |
d899926f | 20 | #include "trace_kprobe_selftest.h" |
8ab83f56 | 21 | #include "trace_probe.h" |
53305928 | 22 | #include "trace_probe_tmpl.h" |
f1d3cbfa | 23 | #include "trace_probe_kernel.h" |
1ff511e3 | 24 | |
8ab83f56 | 25 | #define KPROBE_EVENT_SYSTEM "kprobes" |
696ced4f | 26 | #define KRETPROBE_MAXACTIVE_MAX 4096 |
970988e1 MH |
27 | |
28 | /* Kprobe early definition from command line */ | |
29 | static char kprobe_boot_events_buf[COMMAND_LINE_SIZE] __initdata; | |
30 | ||
31 | static int __init set_kprobe_boot_events(char *str) | |
32 | { | |
c7dce4c5 | 33 | strscpy(kprobe_boot_events_buf, str, COMMAND_LINE_SIZE); |
60efe21e MH |
34 | disable_tracing_selftest("running kprobe events"); |
35 | ||
1d02b444 | 36 | return 1; |
970988e1 MH |
37 | } |
38 | __setup("kprobe_event=", set_kprobe_boot_events); | |
e09c8614 | 39 | |
d262271d | 40 | static int trace_kprobe_create(const char *raw_command); |
6212dd29 MH |
41 | static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev); |
42 | static int trace_kprobe_release(struct dyn_event *ev); | |
43 | static bool trace_kprobe_is_busy(struct dyn_event *ev); | |
44 | static bool trace_kprobe_match(const char *system, const char *event, | |
30199137 | 45 | int argc, const char **argv, struct dyn_event *ev); |
6212dd29 MH |
46 | |
47 | static struct dyn_event_operations trace_kprobe_ops = { | |
48 | .create = trace_kprobe_create, | |
49 | .show = trace_kprobe_show, | |
50 | .is_busy = trace_kprobe_is_busy, | |
51 | .free = trace_kprobe_release, | |
52 | .match = trace_kprobe_match, | |
53 | }; | |
54 | ||
cede666e | 55 | /* |
77b44d1b | 56 | * Kprobe event core functions |
413d37d1 | 57 | */ |
c31ffb3f | 58 | struct trace_kprobe { |
6212dd29 | 59 | struct dyn_event devent; |
4a846b44 | 60 | struct kretprobe rp; /* Use rp.kp for kprobe use */ |
a7636d9e | 61 | unsigned long __percpu *nhit; |
413d37d1 | 62 | const char *symbol; /* symbol name */ |
c31ffb3f | 63 | struct trace_probe tp; |
413d37d1 MH |
64 | }; |
65 | ||
6212dd29 MH |
66 | static bool is_trace_kprobe(struct dyn_event *ev) |
67 | { | |
68 | return ev->ops == &trace_kprobe_ops; | |
69 | } | |
70 | ||
71 | static struct trace_kprobe *to_trace_kprobe(struct dyn_event *ev) | |
72 | { | |
73 | return container_of(ev, struct trace_kprobe, devent); | |
74 | } | |
75 | ||
76 | /** | |
77 | * for_each_trace_kprobe - iterate over the trace_kprobe list | |
78 | * @pos: the struct trace_kprobe * for each entry | |
79 | * @dpos: the struct dyn_event * to use as a loop cursor | |
80 | */ | |
81 | #define for_each_trace_kprobe(pos, dpos) \ | |
82 | for_each_dyn_event(dpos) \ | |
83 | if (is_trace_kprobe(dpos) && (pos = to_trace_kprobe(dpos))) | |
84 | ||
3da0f180 | 85 | static nokprobe_inline bool trace_kprobe_is_return(struct trace_kprobe *tk) |
413d37d1 | 86 | { |
c31ffb3f | 87 | return tk->rp.handler != NULL; |
413d37d1 MH |
88 | } |
89 | ||
3da0f180 | 90 | static nokprobe_inline const char *trace_kprobe_symbol(struct trace_kprobe *tk) |
413d37d1 | 91 | { |
c31ffb3f | 92 | return tk->symbol ? tk->symbol : "unknown"; |
413d37d1 MH |
93 | } |
94 | ||
3da0f180 | 95 | static nokprobe_inline unsigned long trace_kprobe_offset(struct trace_kprobe *tk) |
61424318 | 96 | { |
c31ffb3f | 97 | return tk->rp.kp.offset; |
61424318 MH |
98 | } |
99 | ||
3da0f180 | 100 | static nokprobe_inline bool trace_kprobe_has_gone(struct trace_kprobe *tk) |
61424318 | 101 | { |
29e8077a | 102 | return kprobe_gone(&tk->rp.kp); |
61424318 MH |
103 | } |
104 | ||
3da0f180 | 105 | static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk, |
c31ffb3f | 106 | struct module *mod) |
61424318 | 107 | { |
f3d36426 | 108 | int len = strlen(module_name(mod)); |
c31ffb3f | 109 | const char *name = trace_kprobe_symbol(tk); |
f3d36426 JS |
110 | |
111 | return strncmp(module_name(mod), name, len) == 0 && name[len] == ':'; | |
61424318 MH |
112 | } |
113 | ||
59158ec4 | 114 | static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk) |
61424318 | 115 | { |
59158ec4 MH |
116 | char *p; |
117 | bool ret; | |
118 | ||
119 | if (!tk->symbol) | |
120 | return false; | |
121 | p = strchr(tk->symbol, ':'); | |
122 | if (!p) | |
123 | return true; | |
124 | *p = '\0'; | |
a0060505 | 125 | rcu_read_lock_sched(); |
59158ec4 | 126 | ret = !!find_module(tk->symbol); |
a0060505 | 127 | rcu_read_unlock_sched(); |
59158ec4 MH |
128 | *p = ':'; |
129 | ||
130 | return ret; | |
61424318 MH |
131 | } |
132 | ||
6212dd29 MH |
133 | static bool trace_kprobe_is_busy(struct dyn_event *ev) |
134 | { | |
135 | struct trace_kprobe *tk = to_trace_kprobe(ev); | |
136 | ||
137 | return trace_probe_is_enabled(&tk->tp); | |
138 | } | |
139 | ||
eb5bf813 MH |
140 | static bool trace_kprobe_match_command_head(struct trace_kprobe *tk, |
141 | int argc, const char **argv) | |
142 | { | |
143 | char buf[MAX_ARGSTR_LEN + 1]; | |
144 | ||
145 | if (!argc) | |
146 | return true; | |
147 | ||
148 | if (!tk->symbol) | |
149 | snprintf(buf, sizeof(buf), "0x%p", tk->rp.kp.addr); | |
150 | else if (tk->rp.kp.offset) | |
151 | snprintf(buf, sizeof(buf), "%s+%u", | |
152 | trace_kprobe_symbol(tk), tk->rp.kp.offset); | |
153 | else | |
154 | snprintf(buf, sizeof(buf), "%s", trace_kprobe_symbol(tk)); | |
155 | if (strcmp(buf, argv[0])) | |
156 | return false; | |
157 | argc--; argv++; | |
158 | ||
159 | return trace_probe_match_command_args(&tk->tp, argc, argv); | |
160 | } | |
161 | ||
6212dd29 | 162 | static bool trace_kprobe_match(const char *system, const char *event, |
30199137 | 163 | int argc, const char **argv, struct dyn_event *ev) |
6212dd29 MH |
164 | { |
165 | struct trace_kprobe *tk = to_trace_kprobe(ev); | |
166 | ||
95c104c3 LY |
167 | return (event[0] == '\0' || |
168 | strcmp(trace_probe_name(&tk->tp), event) == 0) && | |
eb5bf813 MH |
169 | (!system || strcmp(trace_probe_group_name(&tk->tp), system) == 0) && |
170 | trace_kprobe_match_command_head(tk, argc, argv); | |
6212dd29 MH |
171 | } |
172 | ||
f18f97ac MN |
173 | static nokprobe_inline unsigned long trace_kprobe_nhit(struct trace_kprobe *tk) |
174 | { | |
175 | unsigned long nhit = 0; | |
176 | int cpu; | |
177 | ||
178 | for_each_possible_cpu(cpu) | |
179 | nhit += *per_cpu_ptr(tk->nhit, cpu); | |
180 | ||
181 | return nhit; | |
182 | } | |
183 | ||
715fa2fd MH |
184 | static nokprobe_inline bool trace_kprobe_is_registered(struct trace_kprobe *tk) |
185 | { | |
186 | return !(list_empty(&tk->rp.kp.list) && | |
187 | hlist_unhashed(&tk->rp.kp.hlist)); | |
188 | } | |
189 | ||
6bc6c77c | 190 | /* Return 0 if it fails to find the symbol address */ |
45408c4f MH |
191 | static nokprobe_inline |
192 | unsigned long trace_kprobe_address(struct trace_kprobe *tk) | |
193 | { | |
194 | unsigned long addr; | |
195 | ||
196 | if (tk->symbol) { | |
197 | addr = (unsigned long) | |
198 | kallsyms_lookup_name(trace_kprobe_symbol(tk)); | |
6bc6c77c MH |
199 | if (addr) |
200 | addr += tk->rp.kp.offset; | |
45408c4f MH |
201 | } else { |
202 | addr = (unsigned long)tk->rp.kp.addr; | |
203 | } | |
204 | return addr; | |
205 | } | |
206 | ||
60d53e2c MH |
207 | static nokprobe_inline struct trace_kprobe * |
208 | trace_kprobe_primary_from_call(struct trace_event_call *call) | |
209 | { | |
210 | struct trace_probe *tp; | |
211 | ||
212 | tp = trace_probe_primary_from_call(call); | |
213 | if (WARN_ON_ONCE(!tp)) | |
214 | return NULL; | |
215 | ||
216 | return container_of(tp, struct trace_kprobe, tp); | |
217 | } | |
218 | ||
b4da3340 | 219 | bool trace_kprobe_on_func_entry(struct trace_event_call *call) |
9802d865 | 220 | { |
60d53e2c | 221 | struct trace_kprobe *tk = trace_kprobe_primary_from_call(call); |
b4da3340 | 222 | |
97c753e6 | 223 | return tk ? (kprobe_on_func_entry(tk->rp.kp.addr, |
b4da3340 | 224 | tk->rp.kp.addr ? NULL : tk->rp.kp.symbol_name, |
97c753e6 | 225 | tk->rp.kp.addr ? 0 : tk->rp.kp.offset) == 0) : false; |
9802d865 JB |
226 | } |
227 | ||
b4da3340 | 228 | bool trace_kprobe_error_injectable(struct trace_event_call *call) |
9802d865 | 229 | { |
60d53e2c | 230 | struct trace_kprobe *tk = trace_kprobe_primary_from_call(call); |
9802d865 | 231 | |
60d53e2c MH |
232 | return tk ? within_error_injection_list(trace_kprobe_address(tk)) : |
233 | false; | |
9802d865 JB |
234 | } |
235 | ||
c31ffb3f NK |
236 | static int register_kprobe_event(struct trace_kprobe *tk); |
237 | static int unregister_kprobe_event(struct trace_kprobe *tk); | |
413d37d1 | 238 | |
50d78056 MH |
239 | static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs); |
240 | static int kretprobe_dispatcher(struct kretprobe_instance *ri, | |
241 | struct pt_regs *regs); | |
242 | ||
455b2899 MH |
243 | static void free_trace_kprobe(struct trace_kprobe *tk) |
244 | { | |
245 | if (tk) { | |
246 | trace_probe_cleanup(&tk->tp); | |
247 | kfree(tk->symbol); | |
248 | free_percpu(tk->nhit); | |
249 | kfree(tk); | |
250 | } | |
251 | } | |
252 | ||
4a846b44 MH |
253 | /* |
254 | * Allocate new trace_probe and initialize it (including kprobes). | |
255 | */ | |
c31ffb3f | 256 | static struct trace_kprobe *alloc_trace_kprobe(const char *group, |
f52487e9 | 257 | const char *event, |
4a846b44 MH |
258 | void *addr, |
259 | const char *symbol, | |
260 | unsigned long offs, | |
696ced4f | 261 | int maxactive, |
3a6b7666 | 262 | int nargs, bool is_return) |
413d37d1 | 263 | { |
c31ffb3f | 264 | struct trace_kprobe *tk; |
6f3cf440 | 265 | int ret = -ENOMEM; |
413d37d1 | 266 | |
845cbf3e | 267 | tk = kzalloc(struct_size(tk, tp.args, nargs), GFP_KERNEL); |
c31ffb3f | 268 | if (!tk) |
6f3cf440 | 269 | return ERR_PTR(ret); |
413d37d1 | 270 | |
a7636d9e MKL |
271 | tk->nhit = alloc_percpu(unsigned long); |
272 | if (!tk->nhit) | |
273 | goto error; | |
274 | ||
413d37d1 | 275 | if (symbol) { |
c31ffb3f NK |
276 | tk->symbol = kstrdup(symbol, GFP_KERNEL); |
277 | if (!tk->symbol) | |
413d37d1 | 278 | goto error; |
c31ffb3f NK |
279 | tk->rp.kp.symbol_name = tk->symbol; |
280 | tk->rp.kp.offset = offs; | |
4a846b44 | 281 | } else |
c31ffb3f | 282 | tk->rp.kp.addr = addr; |
4a846b44 MH |
283 | |
284 | if (is_return) | |
c31ffb3f | 285 | tk->rp.handler = kretprobe_dispatcher; |
4a846b44 | 286 | else |
c31ffb3f | 287 | tk->rp.kp.pre_handler = kprobe_dispatcher; |
4a846b44 | 288 | |
696ced4f | 289 | tk->rp.maxactive = maxactive; |
715fa2fd MH |
290 | INIT_HLIST_NODE(&tk->rp.kp.hlist); |
291 | INIT_LIST_HEAD(&tk->rp.kp.list); | |
696ced4f | 292 | |
b61387cb | 293 | ret = trace_probe_init(&tk->tp, event, group, false); |
455b2899 | 294 | if (ret < 0) |
f52487e9 MH |
295 | goto error; |
296 | ||
6212dd29 | 297 | dyn_event_init(&tk->devent, &trace_kprobe_ops); |
c31ffb3f | 298 | return tk; |
413d37d1 | 299 | error: |
455b2899 | 300 | free_trace_kprobe(tk); |
6f3cf440 | 301 | return ERR_PTR(ret); |
413d37d1 MH |
302 | } |
303 | ||
c31ffb3f NK |
304 | static struct trace_kprobe *find_trace_kprobe(const char *event, |
305 | const char *group) | |
413d37d1 | 306 | { |
6212dd29 | 307 | struct dyn_event *pos; |
c31ffb3f | 308 | struct trace_kprobe *tk; |
413d37d1 | 309 | |
6212dd29 | 310 | for_each_trace_kprobe(tk, pos) |
b55ce203 MH |
311 | if (strcmp(trace_probe_name(&tk->tp), event) == 0 && |
312 | strcmp(trace_probe_group_name(&tk->tp), group) == 0) | |
c31ffb3f | 313 | return tk; |
413d37d1 MH |
314 | return NULL; |
315 | } | |
316 | ||
87107a25 SRV |
317 | static inline int __enable_trace_kprobe(struct trace_kprobe *tk) |
318 | { | |
319 | int ret = 0; | |
320 | ||
715fa2fd | 321 | if (trace_kprobe_is_registered(tk) && !trace_kprobe_has_gone(tk)) { |
87107a25 SRV |
322 | if (trace_kprobe_is_return(tk)) |
323 | ret = enable_kretprobe(&tk->rp); | |
324 | else | |
325 | ret = enable_kprobe(&tk->rp.kp); | |
326 | } | |
327 | ||
328 | return ret; | |
329 | } | |
330 | ||
60d53e2c MH |
331 | static void __disable_trace_kprobe(struct trace_probe *tp) |
332 | { | |
60d53e2c MH |
333 | struct trace_kprobe *tk; |
334 | ||
e161c6bf | 335 | list_for_each_entry(tk, trace_probe_probe_list(tp), tp.list) { |
60d53e2c MH |
336 | if (!trace_kprobe_is_registered(tk)) |
337 | continue; | |
338 | if (trace_kprobe_is_return(tk)) | |
339 | disable_kretprobe(&tk->rp); | |
340 | else | |
341 | disable_kprobe(&tk->rp.kp); | |
342 | } | |
343 | } | |
344 | ||
41a7dd42 MH |
345 | /* |
346 | * Enable trace_probe | |
347 | * if the file is NULL, enable "perf" handler, or enable "trace" handler. | |
348 | */ | |
60d53e2c MH |
349 | static int enable_trace_kprobe(struct trace_event_call *call, |
350 | struct trace_event_file *file) | |
1538f888 | 351 | { |
e161c6bf | 352 | struct trace_probe *tp; |
60d53e2c MH |
353 | struct trace_kprobe *tk; |
354 | bool enabled; | |
1538f888 MH |
355 | int ret = 0; |
356 | ||
60d53e2c MH |
357 | tp = trace_probe_primary_from_call(call); |
358 | if (WARN_ON_ONCE(!tp)) | |
359 | return -ENODEV; | |
360 | enabled = trace_probe_is_enabled(tp); | |
361 | ||
362 | /* This also changes "enabled" state */ | |
41a7dd42 | 363 | if (file) { |
60d53e2c | 364 | ret = trace_probe_add_file(tp, file); |
b5f935ee MH |
365 | if (ret) |
366 | return ret; | |
367 | } else | |
60d53e2c | 368 | trace_probe_set_flag(tp, TP_FLAG_PROFILE); |
41a7dd42 | 369 | |
b5f935ee MH |
370 | if (enabled) |
371 | return 0; | |
87107a25 | 372 | |
e161c6bf | 373 | list_for_each_entry(tk, trace_probe_probe_list(tp), tp.list) { |
60d53e2c MH |
374 | if (trace_kprobe_has_gone(tk)) |
375 | continue; | |
376 | ret = __enable_trace_kprobe(tk); | |
44d00dc7 | 377 | if (ret) |
60d53e2c | 378 | break; |
60d53e2c MH |
379 | enabled = true; |
380 | } | |
381 | ||
44d00dc7 MH |
382 | if (ret) { |
383 | /* Failed to enable one of them. Roll back all */ | |
384 | if (enabled) | |
385 | __disable_trace_kprobe(tp); | |
b5f935ee | 386 | if (file) |
60d53e2c | 387 | trace_probe_remove_file(tp, file); |
b5f935ee | 388 | else |
60d53e2c | 389 | trace_probe_clear_flag(tp, TP_FLAG_PROFILE); |
57ea2a34 | 390 | } |
b5f935ee | 391 | |
1538f888 MH |
392 | return ret; |
393 | } | |
394 | ||
41a7dd42 MH |
395 | /* |
396 | * Disable trace_probe | |
397 | * if the file is NULL, disable "perf" handler, or disable "trace" handler. | |
398 | */ | |
60d53e2c MH |
399 | static int disable_trace_kprobe(struct trace_event_call *call, |
400 | struct trace_event_file *file) | |
1538f888 | 401 | { |
60d53e2c MH |
402 | struct trace_probe *tp; |
403 | ||
404 | tp = trace_probe_primary_from_call(call); | |
405 | if (WARN_ON_ONCE(!tp)) | |
406 | return -ENODEV; | |
41a7dd42 | 407 | |
41a7dd42 | 408 | if (file) { |
b5f935ee MH |
409 | if (!trace_probe_get_file_link(tp, file)) |
410 | return -ENOENT; | |
411 | if (!trace_probe_has_single_file(tp)) | |
b04d52e3 | 412 | goto out; |
747774d6 | 413 | trace_probe_clear_flag(tp, TP_FLAG_TRACE); |
41a7dd42 | 414 | } else |
747774d6 | 415 | trace_probe_clear_flag(tp, TP_FLAG_PROFILE); |
41a7dd42 | 416 | |
60d53e2c MH |
417 | if (!trace_probe_is_enabled(tp)) |
418 | __disable_trace_kprobe(tp); | |
e12f03d7 | 419 | |
3fe3d619 | 420 | out: |
b5f935ee | 421 | if (file) |
a232e270 | 422 | /* |
b5f935ee MH |
423 | * Synchronization is done in below function. For perf event, |
424 | * file == NULL and perf_trace_event_unreg() calls | |
425 | * tracepoint_synchronize_unregister() to ensure synchronize | |
426 | * event. We don't need to care about it. | |
a232e270 | 427 | */ |
b5f935ee | 428 | trace_probe_remove_file(tp, file); |
a232e270 | 429 | |
60d53e2c | 430 | return 0; |
1538f888 MH |
431 | } |
432 | ||
7bb83f6f | 433 | #if defined(CONFIG_DYNAMIC_FTRACE) && \ |
45408c4f | 434 | !defined(CONFIG_KPROBE_EVENTS_ON_NOTRACE) |
c7411a1a | 435 | static bool __within_notrace_func(unsigned long addr) |
45408c4f | 436 | { |
c7411a1a | 437 | unsigned long offset, size; |
45408c4f | 438 | |
6bc6c77c MH |
439 | if (!addr || !kallsyms_lookup_size_offset(addr, &size, &offset)) |
440 | return false; | |
45408c4f | 441 | |
9161a864 MH |
442 | /* Get the entry address of the target function */ |
443 | addr -= offset; | |
444 | ||
445 | /* | |
446 | * Since ftrace_location_range() does inclusive range check, we need | |
447 | * to subtract 1 byte from the end address. | |
448 | */ | |
449 | return !ftrace_location_range(addr, addr + size - 1); | |
45408c4f | 450 | } |
c7411a1a MH |
451 | |
452 | static bool within_notrace_func(struct trace_kprobe *tk) | |
453 | { | |
dcbd21c9 | 454 | unsigned long addr = trace_kprobe_address(tk); |
c7411a1a MH |
455 | char symname[KSYM_NAME_LEN], *p; |
456 | ||
457 | if (!__within_notrace_func(addr)) | |
458 | return false; | |
459 | ||
460 | /* Check if the address is on a suffixed-symbol */ | |
461 | if (!lookup_symbol_name(addr, symname)) { | |
462 | p = strchr(symname, '.'); | |
463 | if (!p) | |
464 | return true; | |
465 | *p = '\0'; | |
466 | addr = (unsigned long)kprobe_lookup_name(symname, 0); | |
467 | if (addr) | |
468 | return __within_notrace_func(addr); | |
469 | } | |
470 | ||
471 | return true; | |
472 | } | |
45408c4f MH |
473 | #else |
474 | #define within_notrace_func(tk) (false) | |
475 | #endif | |
476 | ||
61424318 | 477 | /* Internal register function - just handle k*probes and flags */ |
c31ffb3f | 478 | static int __register_trace_kprobe(struct trace_kprobe *tk) |
413d37d1 | 479 | { |
a6682814 | 480 | int i, ret; |
61424318 | 481 | |
a94549dd DH |
482 | ret = security_locked_down(LOCKDOWN_KPROBES); |
483 | if (ret) | |
484 | return ret; | |
485 | ||
715fa2fd | 486 | if (trace_kprobe_is_registered(tk)) |
61424318 MH |
487 | return -EINVAL; |
488 | ||
45408c4f MH |
489 | if (within_notrace_func(tk)) { |
490 | pr_warn("Could not probe notrace function %s\n", | |
491 | trace_kprobe_symbol(tk)); | |
492 | return -EINVAL; | |
493 | } | |
494 | ||
a6682814 MH |
495 | for (i = 0; i < tk->tp.nr_args; i++) { |
496 | ret = traceprobe_update_arg(&tk->tp.args[i]); | |
497 | if (ret) | |
498 | return ret; | |
499 | } | |
500 | ||
61424318 | 501 | /* Set/clear disabled flag according to tp->flag */ |
c31ffb3f NK |
502 | if (trace_probe_is_enabled(&tk->tp)) |
503 | tk->rp.kp.flags &= ~KPROBE_FLAG_DISABLED; | |
61424318 | 504 | else |
c31ffb3f | 505 | tk->rp.kp.flags |= KPROBE_FLAG_DISABLED; |
61424318 | 506 | |
c31ffb3f NK |
507 | if (trace_kprobe_is_return(tk)) |
508 | ret = register_kretprobe(&tk->rp); | |
413d37d1 | 509 | else |
c31ffb3f | 510 | ret = register_kprobe(&tk->rp.kp); |
61424318 | 511 | |
61424318 MH |
512 | return ret; |
513 | } | |
514 | ||
515 | /* Internal unregister function - just handle k*probes and flags */ | |
c31ffb3f | 516 | static void __unregister_trace_kprobe(struct trace_kprobe *tk) |
61424318 | 517 | { |
715fa2fd | 518 | if (trace_kprobe_is_registered(tk)) { |
c31ffb3f NK |
519 | if (trace_kprobe_is_return(tk)) |
520 | unregister_kretprobe(&tk->rp); | |
61424318 | 521 | else |
c31ffb3f | 522 | unregister_kprobe(&tk->rp.kp); |
715fa2fd MH |
523 | /* Cleanup kprobe for reuse and mark it unregistered */ |
524 | INIT_HLIST_NODE(&tk->rp.kp.hlist); | |
525 | INIT_LIST_HEAD(&tk->rp.kp.list); | |
c31ffb3f NK |
526 | if (tk->rp.kp.symbol_name) |
527 | tk->rp.kp.addr = NULL; | |
61424318 MH |
528 | } |
529 | } | |
530 | ||
6212dd29 | 531 | /* Unregister a trace_probe and probe_event */ |
c31ffb3f | 532 | static int unregister_trace_kprobe(struct trace_kprobe *tk) |
61424318 | 533 | { |
ca89bc07 MH |
534 | /* If other probes are on the event, just unregister kprobe */ |
535 | if (trace_probe_has_sibling(&tk->tp)) | |
536 | goto unreg; | |
537 | ||
02ca1521 | 538 | /* Enabled event can not be unregistered */ |
c31ffb3f | 539 | if (trace_probe_is_enabled(&tk->tp)) |
02ca1521 MH |
540 | return -EBUSY; |
541 | ||
1d18538e SRV |
542 | /* If there's a reference to the dynamic event */ |
543 | if (trace_event_dyn_busy(trace_probe_event_call(&tk->tp))) | |
544 | return -EBUSY; | |
545 | ||
40c32592 | 546 | /* Will fail if probe is being used by ftrace or perf */ |
c31ffb3f | 547 | if (unregister_kprobe_event(tk)) |
40c32592 SRRH |
548 | return -EBUSY; |
549 | ||
ca89bc07 | 550 | unreg: |
c31ffb3f | 551 | __unregister_trace_kprobe(tk); |
6212dd29 | 552 | dyn_event_remove(&tk->devent); |
ca89bc07 | 553 | trace_probe_unlink(&tk->tp); |
02ca1521 MH |
554 | |
555 | return 0; | |
413d37d1 MH |
556 | } |
557 | ||
fe60b0ce MH |
558 | static bool trace_kprobe_has_same_kprobe(struct trace_kprobe *orig, |
559 | struct trace_kprobe *comp) | |
560 | { | |
561 | struct trace_probe_event *tpe = orig->tp.event; | |
fe60b0ce MH |
562 | int i; |
563 | ||
e161c6bf | 564 | list_for_each_entry(orig, &tpe->probes, tp.list) { |
fe60b0ce MH |
565 | if (strcmp(trace_kprobe_symbol(orig), |
566 | trace_kprobe_symbol(comp)) || | |
567 | trace_kprobe_offset(orig) != trace_kprobe_offset(comp)) | |
568 | continue; | |
569 | ||
570 | /* | |
571 | * trace_probe_compare_arg_type() ensured that nr_args and | |
572 | * each argument name and type are same. Let's compare comm. | |
573 | */ | |
574 | for (i = 0; i < orig->tp.nr_args; i++) { | |
575 | if (strcmp(orig->tp.args[i].comm, | |
576 | comp->tp.args[i].comm)) | |
f8d7ab2b | 577 | break; |
fe60b0ce MH |
578 | } |
579 | ||
f8d7ab2b SD |
580 | if (i == orig->tp.nr_args) |
581 | return true; | |
fe60b0ce MH |
582 | } |
583 | ||
584 | return false; | |
585 | } | |
586 | ||
ca89bc07 MH |
587 | static int append_trace_kprobe(struct trace_kprobe *tk, struct trace_kprobe *to) |
588 | { | |
589 | int ret; | |
590 | ||
fe60b0ce MH |
591 | ret = trace_probe_compare_arg_type(&tk->tp, &to->tp); |
592 | if (ret) { | |
593 | /* Note that argument starts index = 2 */ | |
594 | trace_probe_log_set_index(ret + 1); | |
595 | trace_probe_log_err(0, DIFF_ARG_TYPE); | |
596 | return -EEXIST; | |
597 | } | |
598 | if (trace_kprobe_has_same_kprobe(to, tk)) { | |
599 | trace_probe_log_set_index(0); | |
600 | trace_probe_log_err(0, SAME_PROBE); | |
601 | return -EEXIST; | |
602 | } | |
603 | ||
ca89bc07 MH |
604 | /* Append to existing event */ |
605 | ret = trace_probe_append(&tk->tp, &to->tp); | |
606 | if (ret) | |
607 | return ret; | |
608 | ||
609 | /* Register k*probe */ | |
610 | ret = __register_trace_kprobe(tk); | |
611 | if (ret == -ENOENT && !trace_kprobe_module_exist(tk)) { | |
612 | pr_warn("This probe might be able to register after target module is loaded. Continue.\n"); | |
613 | ret = 0; | |
614 | } | |
615 | ||
616 | if (ret) | |
617 | trace_probe_unlink(&tk->tp); | |
618 | else | |
8b0e6c74 | 619 | dyn_event_add(&tk->devent, trace_probe_event_call(&tk->tp)); |
ca89bc07 MH |
620 | |
621 | return ret; | |
622 | } | |
623 | ||
413d37d1 | 624 | /* Register a trace_probe and probe_event */ |
c31ffb3f | 625 | static int register_trace_kprobe(struct trace_kprobe *tk) |
413d37d1 | 626 | { |
c31ffb3f | 627 | struct trace_kprobe *old_tk; |
413d37d1 MH |
628 | int ret; |
629 | ||
6212dd29 | 630 | mutex_lock(&event_mutex); |
413d37d1 | 631 | |
b55ce203 MH |
632 | old_tk = find_trace_kprobe(trace_probe_name(&tk->tp), |
633 | trace_probe_group_name(&tk->tp)); | |
c31ffb3f | 634 | if (old_tk) { |
ca89bc07 MH |
635 | if (trace_kprobe_is_return(tk) != trace_kprobe_is_return(old_tk)) { |
636 | trace_probe_log_set_index(0); | |
637 | trace_probe_log_err(0, DIFF_PROBE_TYPE); | |
638 | ret = -EEXIST; | |
639 | } else { | |
fe60b0ce | 640 | ret = append_trace_kprobe(tk, old_tk); |
ca89bc07 MH |
641 | } |
642 | goto end; | |
2d5e067e | 643 | } |
61424318 MH |
644 | |
645 | /* Register new event */ | |
c31ffb3f | 646 | ret = register_kprobe_event(tk); |
2d5e067e | 647 | if (ret) { |
8e242060 MH |
648 | if (ret == -EEXIST) { |
649 | trace_probe_log_set_index(0); | |
650 | trace_probe_log_err(0, EVENT_EXIST); | |
651 | } else | |
652 | pr_warn("Failed to register probe event(%d)\n", ret); | |
2d5e067e MH |
653 | goto end; |
654 | } | |
655 | ||
61424318 | 656 | /* Register k*probe */ |
c31ffb3f | 657 | ret = __register_trace_kprobe(tk); |
59158ec4 MH |
658 | if (ret == -ENOENT && !trace_kprobe_module_exist(tk)) { |
659 | pr_warn("This probe might be able to register after target module is loaded. Continue.\n"); | |
660 | ret = 0; | |
661 | } | |
662 | ||
61424318 | 663 | if (ret < 0) |
c31ffb3f | 664 | unregister_kprobe_event(tk); |
61424318 | 665 | else |
8b0e6c74 | 666 | dyn_event_add(&tk->devent, trace_probe_event_call(&tk->tp)); |
61424318 | 667 | |
413d37d1 | 668 | end: |
6212dd29 | 669 | mutex_unlock(&event_mutex); |
413d37d1 MH |
670 | return ret; |
671 | } | |
672 | ||
61424318 | 673 | /* Module notifier call back, checking event on the module */ |
c31ffb3f | 674 | static int trace_kprobe_module_callback(struct notifier_block *nb, |
61424318 MH |
675 | unsigned long val, void *data) |
676 | { | |
677 | struct module *mod = data; | |
6212dd29 | 678 | struct dyn_event *pos; |
c31ffb3f | 679 | struct trace_kprobe *tk; |
61424318 MH |
680 | int ret; |
681 | ||
682 | if (val != MODULE_STATE_COMING) | |
683 | return NOTIFY_DONE; | |
684 | ||
685 | /* Update probes on coming module */ | |
6212dd29 MH |
686 | mutex_lock(&event_mutex); |
687 | for_each_trace_kprobe(tk, pos) { | |
c31ffb3f | 688 | if (trace_kprobe_within_module(tk, mod)) { |
02ca1521 | 689 | /* Don't need to check busy - this should have gone. */ |
c31ffb3f NK |
690 | __unregister_trace_kprobe(tk); |
691 | ret = __register_trace_kprobe(tk); | |
61424318 | 692 | if (ret) |
a395d6a7 | 693 | pr_warn("Failed to re-register probe %s on %s: %d\n", |
b55ce203 | 694 | trace_probe_name(&tk->tp), |
f3d36426 | 695 | module_name(mod), ret); |
61424318 MH |
696 | } |
697 | } | |
6212dd29 | 698 | mutex_unlock(&event_mutex); |
61424318 MH |
699 | |
700 | return NOTIFY_DONE; | |
701 | } | |
702 | ||
c31ffb3f NK |
703 | static struct notifier_block trace_kprobe_module_nb = { |
704 | .notifier_call = trace_kprobe_module_callback, | |
61424318 MH |
705 | .priority = 1 /* Invoked after kprobe module callback */ |
706 | }; | |
707 | ||
b022f0c7 FL |
708 | static int count_symbols(void *data, unsigned long unused) |
709 | { | |
710 | unsigned int *count = data; | |
711 | ||
712 | (*count)++; | |
713 | ||
714 | return 0; | |
715 | } | |
716 | ||
926fe783 AN |
717 | struct sym_count_ctx { |
718 | unsigned int count; | |
719 | const char *name; | |
720 | }; | |
721 | ||
722 | static int count_mod_symbols(void *data, const char *name, unsigned long unused) | |
723 | { | |
724 | struct sym_count_ctx *ctx = data; | |
725 | ||
726 | if (strcmp(name, ctx->name) == 0) | |
727 | ctx->count++; | |
728 | ||
729 | return 0; | |
730 | } | |
731 | ||
b022f0c7 FL |
732 | static unsigned int number_of_same_symbols(char *func_name) |
733 | { | |
926fe783 AN |
734 | struct sym_count_ctx ctx = { .count = 0, .name = func_name }; |
735 | ||
736 | kallsyms_on_each_match_symbol(count_symbols, func_name, &ctx.count); | |
b022f0c7 | 737 | |
926fe783 | 738 | module_kallsyms_on_each_symbol(NULL, count_mod_symbols, &ctx); |
b022f0c7 | 739 | |
926fe783 | 740 | return ctx.count; |
b022f0c7 FL |
741 | } |
742 | ||
d262271d | 743 | static int __trace_kprobe_create(int argc, const char *argv[]) |
413d37d1 MH |
744 | { |
745 | /* | |
746 | * Argument syntax: | |
696ced4f | 747 | * - Add kprobe: |
95c104c3 | 748 | * p[:[GRP/][EVENT]] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS] |
696ced4f | 749 | * - Add kretprobe: |
95c104c3 | 750 | * r[MAXACTIVE][:[GRP/][EVENT]] [MOD:]KSYM[+0] [FETCHARGS] |
4725cd89 | 751 | * Or |
95c104c3 | 752 | * p[:[GRP/][EVENT]] [MOD:]KSYM[+0]%return [FETCHARGS] |
4725cd89 | 753 | * |
413d37d1 | 754 | * Fetch args: |
2e06ff63 MH |
755 | * $retval : fetch return value |
756 | * $stack : fetch stack address | |
757 | * $stackN : fetch Nth of stack (N:0-) | |
35abb67d | 758 | * $comm : fetch current task comm |
413d37d1 MH |
759 | * @ADDR : fetch memory at ADDR (ADDR should be in kernel) |
760 | * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol) | |
761 | * %REG : fetch register REG | |
93ccae7a | 762 | * Dereferencing memory fetch: |
413d37d1 | 763 | * +|-offs(ARG) : fetch memory at ARG +|- offs address. |
eca0d916 MH |
764 | * Alias name of args: |
765 | * NAME=FETCHARG : set NAME as alias of FETCHARG. | |
93ccae7a MH |
766 | * Type of args: |
767 | * FETCHARG:TYPE : use TYPE instead of unsigned long. | |
413d37d1 | 768 | */ |
ab105a4f | 769 | struct trace_kprobe *tk = NULL; |
18b1e870 | 770 | int i, len, new_argc = 0, ret = 0; |
6212dd29 MH |
771 | bool is_return = false; |
772 | char *symbol = NULL, *tmp = NULL; | |
18b1e870 | 773 | const char **new_argv = NULL; |
6212dd29 | 774 | const char *event = NULL, *group = KPROBE_EVENT_SYSTEM; |
007517a0 | 775 | enum probe_print_type ptype; |
696ced4f | 776 | int maxactive = 0; |
c5d343b6 | 777 | long offset = 0; |
413d37d1 | 778 | void *addr = NULL; |
4a846b44 | 779 | char buf[MAX_EVENT_NAME_LEN]; |
95c104c3 | 780 | char gbuf[MAX_EVENT_NAME_LEN]; |
18b1e870 | 781 | char abuf[MAX_BTF_ARGS_LEN]; |
b576e097 | 782 | struct traceprobe_parse_context ctx = { .flags = TPARG_FL_KERNEL }; |
413d37d1 | 783 | |
8b05a3a7 AR |
784 | switch (argv[0][0]) { |
785 | case 'r': | |
3a6b7666 | 786 | is_return = true; |
8b05a3a7 AR |
787 | break; |
788 | case 'p': | |
789 | break; | |
790 | default: | |
791 | return -ECANCELED; | |
792 | } | |
793 | if (argc < 2) | |
6212dd29 | 794 | return -ECANCELED; |
413d37d1 | 795 | |
ab105a4f MH |
796 | trace_probe_log_init("trace_kprobe", argc, argv); |
797 | ||
696ced4f | 798 | event = strchr(&argv[0][1], ':'); |
6212dd29 | 799 | if (event) |
696ced4f | 800 | event++; |
6212dd29 | 801 | |
287c038c MH |
802 | if (isdigit(argv[0][1])) { |
803 | if (!is_return) { | |
334e5519 | 804 | trace_probe_log_err(1, BAD_MAXACT_TYPE); |
ab105a4f | 805 | goto parse_error; |
287c038c | 806 | } |
6212dd29 MH |
807 | if (event) |
808 | len = event - &argv[0][1] - 1; | |
809 | else | |
810 | len = strlen(&argv[0][1]); | |
ab105a4f MH |
811 | if (len > MAX_EVENT_NAME_LEN - 1) { |
812 | trace_probe_log_err(1, BAD_MAXACT); | |
813 | goto parse_error; | |
814 | } | |
6212dd29 MH |
815 | memcpy(buf, &argv[0][1], len); |
816 | buf[len] = '\0'; | |
817 | ret = kstrtouint(buf, 0, &maxactive); | |
287c038c | 818 | if (ret || !maxactive) { |
ab105a4f MH |
819 | trace_probe_log_err(1, BAD_MAXACT); |
820 | goto parse_error; | |
696ced4f AC |
821 | } |
822 | /* kretprobes instances are iterated over via a list. The | |
823 | * maximum should stay reasonable. | |
824 | */ | |
825 | if (maxactive > KRETPROBE_MAXACTIVE_MAX) { | |
ab105a4f MH |
826 | trace_probe_log_err(1, MAXACT_TOO_BIG); |
827 | goto parse_error; | |
696ced4f AC |
828 | } |
829 | } | |
830 | ||
9e52b325 SD |
831 | /* try to parse an address. if that fails, try to read the |
832 | * input as a symbol. */ | |
833 | if (kstrtoul(argv[1], 0, (unsigned long *)&addr)) { | |
ab105a4f | 834 | trace_probe_log_set_index(1); |
6212dd29 | 835 | /* Check whether uprobe event specified */ |
ab105a4f MH |
836 | if (strchr(argv[1], '/') && strchr(argv[1], ':')) { |
837 | ret = -ECANCELED; | |
838 | goto error; | |
839 | } | |
413d37d1 | 840 | /* a symbol specified */ |
6212dd29 MH |
841 | symbol = kstrdup(argv[1], GFP_KERNEL); |
842 | if (!symbol) | |
843 | return -ENOMEM; | |
4725cd89 MH |
844 | |
845 | tmp = strchr(symbol, '%'); | |
846 | if (tmp) { | |
847 | if (!strcmp(tmp, "%return")) { | |
848 | *tmp = '\0'; | |
849 | is_return = true; | |
850 | } else { | |
851 | trace_probe_log_err(tmp - symbol, BAD_ADDR_SUFFIX); | |
852 | goto parse_error; | |
853 | } | |
854 | } | |
855 | ||
413d37d1 | 856 | /* TODO: support .init module functions */ |
8ab83f56 | 857 | ret = traceprobe_split_symbol_offset(symbol, &offset); |
c5d343b6 | 858 | if (ret || offset < 0 || offset > UINT_MAX) { |
ab105a4f MH |
859 | trace_probe_log_err(0, BAD_PROBE_ADDR); |
860 | goto parse_error; | |
e63cc239 | 861 | } |
4725cd89 | 862 | if (is_return) |
b576e097 | 863 | ctx.flags |= TPARG_FL_RETURN; |
97c753e6 | 864 | ret = kprobe_on_func_entry(NULL, symbol, offset); |
30460c21 | 865 | if (ret == 0 && !is_return) |
b576e097 | 866 | ctx.flags |= TPARG_FL_FENTRY; |
97c753e6 MH |
867 | /* Defer the ENOENT case until register kprobe */ |
868 | if (ret == -EINVAL && is_return) { | |
ab105a4f MH |
869 | trace_probe_log_err(0, BAD_RETPROBE); |
870 | goto parse_error; | |
e63cc239 | 871 | } |
413d37d1 MH |
872 | } |
873 | ||
b022f0c7 FL |
874 | if (symbol && !strchr(symbol, ':')) { |
875 | unsigned int count; | |
876 | ||
877 | count = number_of_same_symbols(symbol); | |
878 | if (count > 1) { | |
879 | /* | |
880 | * Users should use ADDR to remove the ambiguity of | |
881 | * using KSYM only. | |
882 | */ | |
883 | trace_probe_log_err(0, NON_UNIQ_SYMBOL); | |
884 | ret = -EADDRNOTAVAIL; | |
885 | ||
886 | goto error; | |
887 | } else if (count == 0) { | |
888 | /* | |
889 | * We can return ENOENT earlier than when register the | |
890 | * kprobe. | |
891 | */ | |
892 | trace_probe_log_err(0, BAD_PROBE_ADDR); | |
893 | ret = -ENOENT; | |
894 | ||
895 | goto error; | |
896 | } | |
897 | } | |
898 | ||
ab105a4f | 899 | trace_probe_log_set_index(0); |
6212dd29 | 900 | if (event) { |
95c104c3 | 901 | ret = traceprobe_parse_event_name(&event, &group, gbuf, |
ab105a4f | 902 | event - argv[0]); |
6212dd29 | 903 | if (ret) |
ab105a4f | 904 | goto parse_error; |
95c104c3 LY |
905 | } |
906 | ||
907 | if (!event) { | |
4263565d | 908 | /* Make a new event name */ |
4263565d | 909 | if (symbol) |
6f3cf440 | 910 | snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld", |
4263565d MH |
911 | is_return ? 'r' : 'p', symbol, offset); |
912 | else | |
6f3cf440 | 913 | snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p", |
4263565d | 914 | is_return ? 'r' : 'p', addr); |
fca18a47 | 915 | sanitize_event_name(buf); |
4a846b44 MH |
916 | event = buf; |
917 | } | |
6212dd29 | 918 | |
18b1e870 MHG |
919 | argc -= 2; argv += 2; |
920 | ctx.funcname = symbol; | |
921 | new_argv = traceprobe_expand_meta_args(argc, argv, &new_argc, | |
922 | abuf, MAX_BTF_ARGS_LEN, &ctx); | |
923 | if (IS_ERR(new_argv)) { | |
924 | ret = PTR_ERR(new_argv); | |
925 | new_argv = NULL; | |
926 | goto out; | |
927 | } | |
928 | if (new_argv) { | |
929 | argc = new_argc; | |
930 | argv = new_argv; | |
931 | } | |
932 | ||
6212dd29 | 933 | /* setup a probe */ |
696ced4f | 934 | tk = alloc_trace_kprobe(group, event, addr, symbol, offset, maxactive, |
18b1e870 | 935 | argc, is_return); |
c31ffb3f | 936 | if (IS_ERR(tk)) { |
6212dd29 | 937 | ret = PTR_ERR(tk); |
ab105a4f | 938 | /* This must return -ENOMEM, else there is a bug */ |
a039480e | 939 | WARN_ON_ONCE(ret != -ENOMEM); |
ab105a4f | 940 | goto out; /* We know tk is not allocated */ |
e63cc239 | 941 | } |
413d37d1 | 942 | |
413d37d1 | 943 | /* parse arguments */ |
a82378d8 | 944 | for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { |
ab105a4f | 945 | trace_probe_log_set_index(i + 2); |
b576e097 | 946 | ctx.offset = 0; |
1b8b0cd7 | 947 | ret = traceprobe_parse_probe_arg(&tk->tp, i, argv[i], &ctx); |
d00bbea9 | 948 | if (ret) |
ab105a4f | 949 | goto error; /* This can be -ENOMEM */ |
413d37d1 | 950 | } |
413d37d1 | 951 | |
007517a0 SRV |
952 | ptype = is_return ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL; |
953 | ret = traceprobe_set_print_fmt(&tk->tp, ptype); | |
f730e0f2 MH |
954 | if (ret < 0) |
955 | goto error; | |
956 | ||
c31ffb3f | 957 | ret = register_trace_kprobe(tk); |
ab105a4f MH |
958 | if (ret) { |
959 | trace_probe_log_set_index(1); | |
960 | if (ret == -EILSEQ) | |
961 | trace_probe_log_err(0, BAD_INSN_BNDRY); | |
962 | else if (ret == -ENOENT) | |
963 | trace_probe_log_err(0, BAD_PROBE_ADDR); | |
ca89bc07 | 964 | else if (ret != -ENOMEM && ret != -EEXIST) |
ab105a4f | 965 | trace_probe_log_err(0, FAIL_REG_PROBE); |
413d37d1 | 966 | goto error; |
ab105a4f MH |
967 | } |
968 | ||
6212dd29 | 969 | out: |
b1d1e904 | 970 | traceprobe_finish_parse(&ctx); |
ab105a4f | 971 | trace_probe_log_clear(); |
18b1e870 | 972 | kfree(new_argv); |
6212dd29 MH |
973 | kfree(symbol); |
974 | return ret; | |
413d37d1 | 975 | |
ab105a4f MH |
976 | parse_error: |
977 | ret = -EINVAL; | |
413d37d1 | 978 | error: |
c31ffb3f | 979 | free_trace_kprobe(tk); |
6212dd29 | 980 | goto out; |
413d37d1 MH |
981 | } |
982 | ||
d262271d MH |
983 | static int trace_kprobe_create(const char *raw_command) |
984 | { | |
985 | return trace_probe_create(raw_command, __trace_kprobe_create); | |
986 | } | |
987 | ||
988 | static int create_or_delete_trace_kprobe(const char *raw_command) | |
413d37d1 | 989 | { |
6212dd29 | 990 | int ret; |
02ca1521 | 991 | |
d262271d MH |
992 | if (raw_command[0] == '-') |
993 | return dyn_event_release(raw_command, &trace_kprobe_ops); | |
413d37d1 | 994 | |
d262271d | 995 | ret = trace_kprobe_create(raw_command); |
6212dd29 | 996 | return ret == -ECANCELED ? -EINVAL : ret; |
413d37d1 MH |
997 | } |
998 | ||
29a15481 | 999 | static int trace_kprobe_run_command(struct dynevent_cmd *cmd) |
2a588dd1 | 1000 | { |
d262271d | 1001 | return create_or_delete_trace_kprobe(cmd->seq.buffer); |
2a588dd1 TZ |
1002 | } |
1003 | ||
1004 | /** | |
1005 | * kprobe_event_cmd_init - Initialize a kprobe event command object | |
1006 | * @cmd: A pointer to the dynevent_cmd struct representing the new event | |
1007 | * @buf: A pointer to the buffer used to build the command | |
1008 | * @maxlen: The length of the buffer passed in @buf | |
1009 | * | |
1010 | * Initialize a synthetic event command object. Use this before | |
1011 | * calling any of the other kprobe_event functions. | |
1012 | */ | |
1013 | void kprobe_event_cmd_init(struct dynevent_cmd *cmd, char *buf, int maxlen) | |
1014 | { | |
1015 | dynevent_cmd_init(cmd, buf, maxlen, DYNEVENT_TYPE_KPROBE, | |
29a15481 | 1016 | trace_kprobe_run_command); |
2a588dd1 TZ |
1017 | } |
1018 | EXPORT_SYMBOL_GPL(kprobe_event_cmd_init); | |
1019 | ||
1020 | /** | |
1021 | * __kprobe_event_gen_cmd_start - Generate a kprobe event command from arg list | |
1022 | * @cmd: A pointer to the dynevent_cmd struct representing the new event | |
f032c53b | 1023 | * @kretprobe: Is this a return probe? |
2a588dd1 TZ |
1024 | * @name: The name of the kprobe event |
1025 | * @loc: The location of the kprobe event | |
e0f83183 | 1026 | * @...: Variable number of arg (pairs), one pair for each field |
2a588dd1 TZ |
1027 | * |
1028 | * NOTE: Users normally won't want to call this function directly, but | |
1029 | * rather use the kprobe_event_gen_cmd_start() wrapper, which automatically | |
1030 | * adds a NULL to the end of the arg list. If this function is used | |
1031 | * directly, make sure the last arg in the variable arg list is NULL. | |
1032 | * | |
1033 | * Generate a kprobe event command to be executed by | |
1034 | * kprobe_event_gen_cmd_end(). This function can be used to generate the | |
1035 | * complete command or only the first part of it; in the latter case, | |
1036 | * kprobe_event_add_fields() can be used to add more fields following this. | |
1037 | * | |
5b4dcd2d MH |
1038 | * Unlikely the synth_event_gen_cmd_start(), @loc must be specified. This |
1039 | * returns -EINVAL if @loc == NULL. | |
1040 | * | |
2a588dd1 TZ |
1041 | * Return: 0 if successful, error otherwise. |
1042 | */ | |
1043 | int __kprobe_event_gen_cmd_start(struct dynevent_cmd *cmd, bool kretprobe, | |
1044 | const char *name, const char *loc, ...) | |
1045 | { | |
1046 | char buf[MAX_EVENT_NAME_LEN]; | |
1047 | struct dynevent_arg arg; | |
1048 | va_list args; | |
1049 | int ret; | |
1050 | ||
1051 | if (cmd->type != DYNEVENT_TYPE_KPROBE) | |
1052 | return -EINVAL; | |
1053 | ||
5b4dcd2d MH |
1054 | if (!loc) |
1055 | return -EINVAL; | |
1056 | ||
2a588dd1 TZ |
1057 | if (kretprobe) |
1058 | snprintf(buf, MAX_EVENT_NAME_LEN, "r:kprobes/%s", name); | |
1059 | else | |
1060 | snprintf(buf, MAX_EVENT_NAME_LEN, "p:kprobes/%s", name); | |
1061 | ||
1062 | ret = dynevent_str_add(cmd, buf); | |
1063 | if (ret) | |
1064 | return ret; | |
1065 | ||
74403b6c | 1066 | dynevent_arg_init(&arg, 0); |
2a588dd1 | 1067 | arg.str = loc; |
74403b6c | 1068 | ret = dynevent_arg_add(cmd, &arg, NULL); |
2a588dd1 TZ |
1069 | if (ret) |
1070 | return ret; | |
1071 | ||
1072 | va_start(args, loc); | |
1073 | for (;;) { | |
1074 | const char *field; | |
1075 | ||
1076 | field = va_arg(args, const char *); | |
1077 | if (!field) | |
1078 | break; | |
1079 | ||
1080 | if (++cmd->n_fields > MAX_TRACE_ARGS) { | |
1081 | ret = -EINVAL; | |
1082 | break; | |
1083 | } | |
1084 | ||
1085 | arg.str = field; | |
74403b6c | 1086 | ret = dynevent_arg_add(cmd, &arg, NULL); |
2a588dd1 TZ |
1087 | if (ret) |
1088 | break; | |
1089 | } | |
1090 | va_end(args); | |
1091 | ||
1092 | return ret; | |
1093 | } | |
1094 | EXPORT_SYMBOL_GPL(__kprobe_event_gen_cmd_start); | |
1095 | ||
1096 | /** | |
1097 | * __kprobe_event_add_fields - Add probe fields to a kprobe command from arg list | |
1098 | * @cmd: A pointer to the dynevent_cmd struct representing the new event | |
e0f83183 | 1099 | * @...: Variable number of arg (pairs), one pair for each field |
2a588dd1 TZ |
1100 | * |
1101 | * NOTE: Users normally won't want to call this function directly, but | |
1102 | * rather use the kprobe_event_add_fields() wrapper, which | |
1103 | * automatically adds a NULL to the end of the arg list. If this | |
1104 | * function is used directly, make sure the last arg in the variable | |
1105 | * arg list is NULL. | |
1106 | * | |
1107 | * Add probe fields to an existing kprobe command using a variable | |
1108 | * list of args. Fields are added in the same order they're listed. | |
1109 | * | |
1110 | * Return: 0 if successful, error otherwise. | |
1111 | */ | |
1112 | int __kprobe_event_add_fields(struct dynevent_cmd *cmd, ...) | |
1113 | { | |
1114 | struct dynevent_arg arg; | |
1115 | va_list args; | |
10f129cb | 1116 | int ret = 0; |
2a588dd1 TZ |
1117 | |
1118 | if (cmd->type != DYNEVENT_TYPE_KPROBE) | |
1119 | return -EINVAL; | |
1120 | ||
74403b6c | 1121 | dynevent_arg_init(&arg, 0); |
2a588dd1 TZ |
1122 | |
1123 | va_start(args, cmd); | |
1124 | for (;;) { | |
1125 | const char *field; | |
1126 | ||
1127 | field = va_arg(args, const char *); | |
1128 | if (!field) | |
1129 | break; | |
1130 | ||
1131 | if (++cmd->n_fields > MAX_TRACE_ARGS) { | |
1132 | ret = -EINVAL; | |
1133 | break; | |
1134 | } | |
1135 | ||
1136 | arg.str = field; | |
74403b6c | 1137 | ret = dynevent_arg_add(cmd, &arg, NULL); |
2a588dd1 TZ |
1138 | if (ret) |
1139 | break; | |
1140 | } | |
1141 | va_end(args); | |
1142 | ||
1143 | return ret; | |
1144 | } | |
1145 | EXPORT_SYMBOL_GPL(__kprobe_event_add_fields); | |
1146 | ||
1147 | /** | |
1148 | * kprobe_event_delete - Delete a kprobe event | |
1149 | * @name: The name of the kprobe event to delete | |
1150 | * | |
1151 | * Delete a kprobe event with the give @name from kernel code rather | |
1152 | * than directly from the command line. | |
1153 | * | |
1154 | * Return: 0 if successful, error otherwise. | |
1155 | */ | |
1156 | int kprobe_event_delete(const char *name) | |
1157 | { | |
1158 | char buf[MAX_EVENT_NAME_LEN]; | |
1159 | ||
1160 | snprintf(buf, MAX_EVENT_NAME_LEN, "-:%s", name); | |
1161 | ||
d262271d | 1162 | return create_or_delete_trace_kprobe(buf); |
2a588dd1 TZ |
1163 | } |
1164 | EXPORT_SYMBOL_GPL(kprobe_event_delete); | |
1165 | ||
6212dd29 | 1166 | static int trace_kprobe_release(struct dyn_event *ev) |
413d37d1 | 1167 | { |
6212dd29 MH |
1168 | struct trace_kprobe *tk = to_trace_kprobe(ev); |
1169 | int ret = unregister_trace_kprobe(tk); | |
413d37d1 | 1170 | |
6212dd29 MH |
1171 | if (!ret) |
1172 | free_trace_kprobe(tk); | |
1173 | return ret; | |
413d37d1 MH |
1174 | } |
1175 | ||
6212dd29 | 1176 | static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev) |
413d37d1 | 1177 | { |
6212dd29 | 1178 | struct trace_kprobe *tk = to_trace_kprobe(ev); |
93ccae7a | 1179 | int i; |
413d37d1 | 1180 | |
fa6f0cc7 | 1181 | seq_putc(m, trace_kprobe_is_return(tk) ? 'r' : 'p'); |
6a13a0d7 MH |
1182 | if (trace_kprobe_is_return(tk) && tk->rp.maxactive) |
1183 | seq_printf(m, "%d", tk->rp.maxactive); | |
b55ce203 MH |
1184 | seq_printf(m, ":%s/%s", trace_probe_group_name(&tk->tp), |
1185 | trace_probe_name(&tk->tp)); | |
413d37d1 | 1186 | |
c31ffb3f NK |
1187 | if (!tk->symbol) |
1188 | seq_printf(m, " 0x%p", tk->rp.kp.addr); | |
1189 | else if (tk->rp.kp.offset) | |
1190 | seq_printf(m, " %s+%u", trace_kprobe_symbol(tk), | |
1191 | tk->rp.kp.offset); | |
413d37d1 | 1192 | else |
c31ffb3f | 1193 | seq_printf(m, " %s", trace_kprobe_symbol(tk)); |
413d37d1 | 1194 | |
c31ffb3f NK |
1195 | for (i = 0; i < tk->tp.nr_args; i++) |
1196 | seq_printf(m, " %s=%s", tk->tp.args[i].name, tk->tp.args[i].comm); | |
fa6f0cc7 | 1197 | seq_putc(m, '\n'); |
93ccae7a | 1198 | |
413d37d1 MH |
1199 | return 0; |
1200 | } | |
1201 | ||
6212dd29 MH |
1202 | static int probes_seq_show(struct seq_file *m, void *v) |
1203 | { | |
1204 | struct dyn_event *ev = v; | |
1205 | ||
1206 | if (!is_trace_kprobe(ev)) | |
1207 | return 0; | |
1208 | ||
1209 | return trace_kprobe_show(m, ev); | |
1210 | } | |
1211 | ||
413d37d1 | 1212 | static const struct seq_operations probes_seq_op = { |
6212dd29 MH |
1213 | .start = dyn_event_seq_start, |
1214 | .next = dyn_event_seq_next, | |
1215 | .stop = dyn_event_seq_stop, | |
413d37d1 MH |
1216 | .show = probes_seq_show |
1217 | }; | |
1218 | ||
1219 | static int probes_open(struct inode *inode, struct file *file) | |
1220 | { | |
02ca1521 MH |
1221 | int ret; |
1222 | ||
17911ff3 SRV |
1223 | ret = security_locked_down(LOCKDOWN_TRACEFS); |
1224 | if (ret) | |
1225 | return ret; | |
1226 | ||
02ca1521 | 1227 | if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { |
6212dd29 | 1228 | ret = dyn_events_release_all(&trace_kprobe_ops); |
02ca1521 MH |
1229 | if (ret < 0) |
1230 | return ret; | |
1231 | } | |
413d37d1 MH |
1232 | |
1233 | return seq_open(file, &probes_seq_op); | |
1234 | } | |
1235 | ||
413d37d1 MH |
1236 | static ssize_t probes_write(struct file *file, const char __user *buffer, |
1237 | size_t count, loff_t *ppos) | |
1238 | { | |
7e465baa | 1239 | return trace_parse_run_command(file, buffer, count, ppos, |
6212dd29 | 1240 | create_or_delete_trace_kprobe); |
413d37d1 MH |
1241 | } |
1242 | ||
1243 | static const struct file_operations kprobe_events_ops = { | |
1244 | .owner = THIS_MODULE, | |
1245 | .open = probes_open, | |
1246 | .read = seq_read, | |
1247 | .llseek = seq_lseek, | |
1248 | .release = seq_release, | |
1249 | .write = probes_write, | |
1250 | }; | |
1251 | ||
3acf8ace JO |
1252 | static unsigned long trace_kprobe_missed(struct trace_kprobe *tk) |
1253 | { | |
1254 | return trace_kprobe_is_return(tk) ? | |
1255 | tk->rp.kp.nmissed + tk->rp.nmissed : tk->rp.kp.nmissed; | |
1256 | } | |
1257 | ||
cd7e7bd5 MH |
1258 | /* Probes profiling interfaces */ |
1259 | static int probes_profile_seq_show(struct seq_file *m, void *v) | |
1260 | { | |
6212dd29 MH |
1261 | struct dyn_event *ev = v; |
1262 | struct trace_kprobe *tk; | |
dfea08a2 | 1263 | unsigned long nmissed; |
cd7e7bd5 | 1264 | |
6212dd29 MH |
1265 | if (!is_trace_kprobe(ev)) |
1266 | return 0; | |
cd7e7bd5 | 1267 | |
6212dd29 | 1268 | tk = to_trace_kprobe(ev); |
3acf8ace | 1269 | nmissed = trace_kprobe_missed(tk); |
de7b2973 | 1270 | seq_printf(m, " %-44s %15lu %15lu\n", |
b55ce203 | 1271 | trace_probe_name(&tk->tp), |
f18f97ac | 1272 | trace_kprobe_nhit(tk), |
dfea08a2 | 1273 | nmissed); |
cd7e7bd5 MH |
1274 | |
1275 | return 0; | |
1276 | } | |
1277 | ||
1278 | static const struct seq_operations profile_seq_op = { | |
6212dd29 MH |
1279 | .start = dyn_event_seq_start, |
1280 | .next = dyn_event_seq_next, | |
1281 | .stop = dyn_event_seq_stop, | |
cd7e7bd5 MH |
1282 | .show = probes_profile_seq_show |
1283 | }; | |
1284 | ||
1285 | static int profile_open(struct inode *inode, struct file *file) | |
1286 | { | |
17911ff3 SRV |
1287 | int ret; |
1288 | ||
1289 | ret = security_locked_down(LOCKDOWN_TRACEFS); | |
1290 | if (ret) | |
1291 | return ret; | |
1292 | ||
cd7e7bd5 MH |
1293 | return seq_open(file, &profile_seq_op); |
1294 | } | |
1295 | ||
1296 | static const struct file_operations kprobe_profile_ops = { | |
1297 | .owner = THIS_MODULE, | |
1298 | .open = profile_open, | |
1299 | .read = seq_read, | |
1300 | .llseek = seq_lseek, | |
1301 | .release = seq_release, | |
1302 | }; | |
1303 | ||
53305928 MH |
1304 | /* Note that we don't verify it, since the code does not come from user space */ |
1305 | static int | |
8565a45d | 1306 | process_fetch_insn(struct fetch_insn *code, void *rec, void *dest, |
9178412d | 1307 | void *base) |
53305928 | 1308 | { |
8565a45d | 1309 | struct pt_regs *regs = rec; |
53305928 | 1310 | unsigned long val; |
bd78acc8 | 1311 | int ret; |
53305928 | 1312 | |
a6682814 | 1313 | retry: |
53305928 MH |
1314 | /* 1st stage: get value from context */ |
1315 | switch (code->op) { | |
1316 | case FETCH_OP_REG: | |
1317 | val = regs_get_register(regs, code->param); | |
1318 | break; | |
1319 | case FETCH_OP_STACK: | |
1320 | val = regs_get_kernel_stack_nth(regs, code->param); | |
1321 | break; | |
1322 | case FETCH_OP_STACKP: | |
1323 | val = kernel_stack_pointer(regs); | |
1324 | break; | |
1325 | case FETCH_OP_RETVAL: | |
1326 | val = regs_return_value(regs); | |
1327 | break; | |
a1303af5 MH |
1328 | #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API |
1329 | case FETCH_OP_ARG: | |
1330 | val = regs_get_kernel_argument(regs, code->param); | |
1331 | break; | |
1332 | #endif | |
a6682814 MH |
1333 | case FETCH_NOP_SYMBOL: /* Ignore a place holder */ |
1334 | code++; | |
1335 | goto retry; | |
53305928 | 1336 | default: |
bd78acc8 SC |
1337 | ret = process_common_fetch_insn(code, &val); |
1338 | if (ret < 0) | |
1339 | return ret; | |
53305928 MH |
1340 | } |
1341 | code++; | |
1342 | ||
9b960a38 | 1343 | return process_fetch_insn_bottom(code, val, dest, base); |
53305928 MH |
1344 | } |
1345 | NOKPROBE_SYMBOL(process_fetch_insn) | |
1346 | ||
413d37d1 | 1347 | /* Kprobe handler */ |
3da0f180 | 1348 | static nokprobe_inline void |
c31ffb3f | 1349 | __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs, |
7f1d2f82 | 1350 | struct trace_event_file *trace_file) |
413d37d1 | 1351 | { |
93ccae7a | 1352 | struct kprobe_trace_entry_head *entry; |
e3dc9f89 | 1353 | struct trace_event_call *call = trace_probe_event_call(&tk->tp); |
8cfcf155 MH |
1354 | struct trace_event_buffer fbuffer; |
1355 | int dsize; | |
413d37d1 | 1356 | |
7f1d2f82 | 1357 | WARN_ON(call != trace_file->event_call); |
41a7dd42 | 1358 | |
09a5059a | 1359 | if (trace_trigger_soft_disabled(trace_file)) |
13a1e4ae | 1360 | return; |
b8820084 | 1361 | |
c31ffb3f | 1362 | dsize = __get_data_size(&tk->tp, regs); |
413d37d1 | 1363 | |
5e6cd84e SRV |
1364 | entry = trace_event_buffer_reserve(&fbuffer, trace_file, |
1365 | sizeof(*entry) + tk->tp.size + dsize); | |
1366 | if (!entry) | |
1e12a4a7 | 1367 | return; |
413d37d1 | 1368 | |
8cfcf155 | 1369 | fbuffer.regs = regs; |
c31ffb3f | 1370 | entry->ip = (unsigned long)tk->rp.kp.addr; |
9178412d | 1371 | store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize); |
413d37d1 | 1372 | |
8cfcf155 | 1373 | trace_event_buffer_commit(&fbuffer); |
413d37d1 MH |
1374 | } |
1375 | ||
3da0f180 | 1376 | static void |
c31ffb3f | 1377 | kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs) |
41a7dd42 | 1378 | { |
b04d52e3 | 1379 | struct event_file_link *link; |
41a7dd42 | 1380 | |
b5f935ee | 1381 | trace_probe_for_each_link_rcu(link, &tk->tp) |
c31ffb3f | 1382 | __kprobe_trace_func(tk, regs, link->file); |
41a7dd42 | 1383 | } |
3da0f180 | 1384 | NOKPROBE_SYMBOL(kprobe_trace_func); |
41a7dd42 | 1385 | |
413d37d1 | 1386 | /* Kretprobe handler */ |
3da0f180 | 1387 | static nokprobe_inline void |
c31ffb3f | 1388 | __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, |
41a7dd42 | 1389 | struct pt_regs *regs, |
7f1d2f82 | 1390 | struct trace_event_file *trace_file) |
413d37d1 | 1391 | { |
93ccae7a | 1392 | struct kretprobe_trace_entry_head *entry; |
8cfcf155 | 1393 | struct trace_event_buffer fbuffer; |
e3dc9f89 | 1394 | struct trace_event_call *call = trace_probe_event_call(&tk->tp); |
8cfcf155 | 1395 | int dsize; |
413d37d1 | 1396 | |
7f1d2f82 | 1397 | WARN_ON(call != trace_file->event_call); |
41a7dd42 | 1398 | |
09a5059a | 1399 | if (trace_trigger_soft_disabled(trace_file)) |
13a1e4ae | 1400 | return; |
b8820084 | 1401 | |
c31ffb3f | 1402 | dsize = __get_data_size(&tk->tp, regs); |
5e6cd84e SRV |
1403 | |
1404 | entry = trace_event_buffer_reserve(&fbuffer, trace_file, | |
1405 | sizeof(*entry) + tk->tp.size + dsize); | |
1406 | if (!entry) | |
1e12a4a7 | 1407 | return; |
413d37d1 | 1408 | |
8cfcf155 | 1409 | fbuffer.regs = regs; |
c31ffb3f | 1410 | entry->func = (unsigned long)tk->rp.kp.addr; |
73f9b911 | 1411 | entry->ret_ip = get_kretprobe_retaddr(ri); |
9178412d | 1412 | store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize); |
413d37d1 | 1413 | |
8cfcf155 | 1414 | trace_event_buffer_commit(&fbuffer); |
413d37d1 MH |
1415 | } |
1416 | ||
3da0f180 | 1417 | static void |
c31ffb3f | 1418 | kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, |
41a7dd42 MH |
1419 | struct pt_regs *regs) |
1420 | { | |
b04d52e3 | 1421 | struct event_file_link *link; |
41a7dd42 | 1422 | |
b5f935ee | 1423 | trace_probe_for_each_link_rcu(link, &tk->tp) |
c31ffb3f | 1424 | __kretprobe_trace_func(tk, ri, regs, link->file); |
41a7dd42 | 1425 | } |
3da0f180 | 1426 | NOKPROBE_SYMBOL(kretprobe_trace_func); |
41a7dd42 | 1427 | |
413d37d1 | 1428 | /* Event entry printers */ |
b62fdd97 | 1429 | static enum print_line_t |
a9a57763 SR |
1430 | print_kprobe_event(struct trace_iterator *iter, int flags, |
1431 | struct trace_event *event) | |
413d37d1 | 1432 | { |
93ccae7a | 1433 | struct kprobe_trace_entry_head *field; |
413d37d1 | 1434 | struct trace_seq *s = &iter->seq; |
eca0d916 | 1435 | struct trace_probe *tp; |
413d37d1 | 1436 | |
93ccae7a | 1437 | field = (struct kprobe_trace_entry_head *)iter->ent; |
60d53e2c MH |
1438 | tp = trace_probe_primary_from_call( |
1439 | container_of(event, struct trace_event_call, event)); | |
1440 | if (WARN_ON_ONCE(!tp)) | |
1441 | goto out; | |
413d37d1 | 1442 | |
b55ce203 | 1443 | trace_seq_printf(s, "%s: (", trace_probe_name(tp)); |
6e9f23d1 | 1444 | |
413d37d1 | 1445 | if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET)) |
85224da0 | 1446 | goto out; |
413d37d1 | 1447 | |
85224da0 | 1448 | trace_seq_putc(s, ')'); |
413d37d1 | 1449 | |
196b6389 | 1450 | if (trace_probe_print_args(s, tp->args, tp->nr_args, |
56de7630 MH |
1451 | (u8 *)&field[1], field) < 0) |
1452 | goto out; | |
413d37d1 | 1453 | |
85224da0 SRRH |
1454 | trace_seq_putc(s, '\n'); |
1455 | out: | |
1456 | return trace_handle_return(s); | |
413d37d1 MH |
1457 | } |
1458 | ||
b62fdd97 | 1459 | static enum print_line_t |
a9a57763 SR |
1460 | print_kretprobe_event(struct trace_iterator *iter, int flags, |
1461 | struct trace_event *event) | |
413d37d1 | 1462 | { |
93ccae7a | 1463 | struct kretprobe_trace_entry_head *field; |
413d37d1 | 1464 | struct trace_seq *s = &iter->seq; |
eca0d916 | 1465 | struct trace_probe *tp; |
413d37d1 | 1466 | |
93ccae7a | 1467 | field = (struct kretprobe_trace_entry_head *)iter->ent; |
60d53e2c MH |
1468 | tp = trace_probe_primary_from_call( |
1469 | container_of(event, struct trace_event_call, event)); | |
1470 | if (WARN_ON_ONCE(!tp)) | |
1471 | goto out; | |
413d37d1 | 1472 | |
b55ce203 | 1473 | trace_seq_printf(s, "%s: (", trace_probe_name(tp)); |
6e9f23d1 | 1474 | |
413d37d1 | 1475 | if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET)) |
85224da0 | 1476 | goto out; |
413d37d1 | 1477 | |
85224da0 | 1478 | trace_seq_puts(s, " <- "); |
413d37d1 MH |
1479 | |
1480 | if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET)) | |
85224da0 | 1481 | goto out; |
413d37d1 | 1482 | |
85224da0 | 1483 | trace_seq_putc(s, ')'); |
413d37d1 | 1484 | |
196b6389 | 1485 | if (trace_probe_print_args(s, tp->args, tp->nr_args, |
56de7630 MH |
1486 | (u8 *)&field[1], field) < 0) |
1487 | goto out; | |
413d37d1 | 1488 | |
85224da0 | 1489 | trace_seq_putc(s, '\n'); |
413d37d1 | 1490 | |
85224da0 SRRH |
1491 | out: |
1492 | return trace_handle_return(s); | |
413d37d1 MH |
1493 | } |
1494 | ||
413d37d1 | 1495 | |
2425bcb9 | 1496 | static int kprobe_event_define_fields(struct trace_event_call *event_call) |
413d37d1 | 1497 | { |
eeb07b06 | 1498 | int ret; |
93ccae7a | 1499 | struct kprobe_trace_entry_head field; |
60d53e2c MH |
1500 | struct trace_probe *tp; |
1501 | ||
1502 | tp = trace_probe_primary_from_call(event_call); | |
1503 | if (WARN_ON_ONCE(!tp)) | |
1504 | return -ENOENT; | |
413d37d1 | 1505 | |
a703d946 | 1506 | DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0); |
c31ffb3f | 1507 | |
60d53e2c | 1508 | return traceprobe_define_arg_fields(event_call, sizeof(field), tp); |
413d37d1 MH |
1509 | } |
1510 | ||
2425bcb9 | 1511 | static int kretprobe_event_define_fields(struct trace_event_call *event_call) |
413d37d1 | 1512 | { |
eeb07b06 | 1513 | int ret; |
93ccae7a | 1514 | struct kretprobe_trace_entry_head field; |
60d53e2c MH |
1515 | struct trace_probe *tp; |
1516 | ||
1517 | tp = trace_probe_primary_from_call(event_call); | |
1518 | if (WARN_ON_ONCE(!tp)) | |
1519 | return -ENOENT; | |
413d37d1 | 1520 | |
a703d946 MH |
1521 | DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0); |
1522 | DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0); | |
c31ffb3f | 1523 | |
60d53e2c | 1524 | return traceprobe_define_arg_fields(event_call, sizeof(field), tp); |
413d37d1 MH |
1525 | } |
1526 | ||
07b139c8 | 1527 | #ifdef CONFIG_PERF_EVENTS |
e08d1c65 MH |
1528 | |
1529 | /* Kprobe profile handler */ | |
9802d865 | 1530 | static int |
c31ffb3f | 1531 | kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs) |
e08d1c65 | 1532 | { |
e3dc9f89 | 1533 | struct trace_event_call *call = trace_probe_event_call(&tk->tp); |
93ccae7a | 1534 | struct kprobe_trace_entry_head *entry; |
1c024eca | 1535 | struct hlist_head *head; |
e09c8614 | 1536 | int size, __size, dsize; |
4ed7c92d | 1537 | int rctx; |
e08d1c65 | 1538 | |
9802d865 | 1539 | if (bpf_prog_array_valid(call)) { |
66665ad2 | 1540 | unsigned long orig_ip = instruction_pointer(regs); |
9802d865 JB |
1541 | int ret; |
1542 | ||
1543 | ret = trace_call_bpf(call, regs); | |
1544 | ||
1545 | /* | |
1546 | * We need to check and see if we modified the pc of the | |
cce188bd MH |
1547 | * pt_regs, and if so return 1 so that we don't do the |
1548 | * single stepping. | |
9802d865 | 1549 | */ |
cce188bd | 1550 | if (orig_ip != instruction_pointer(regs)) |
9802d865 | 1551 | return 1; |
9802d865 JB |
1552 | if (!ret) |
1553 | return 0; | |
1554 | } | |
2541517c | 1555 | |
288e984e ON |
1556 | head = this_cpu_ptr(call->perf_events); |
1557 | if (hlist_empty(head)) | |
9802d865 | 1558 | return 0; |
288e984e | 1559 | |
c31ffb3f NK |
1560 | dsize = __get_data_size(&tk->tp, regs); |
1561 | __size = sizeof(*entry) + tk->tp.size + dsize; | |
74ebb63e MH |
1562 | size = ALIGN(__size + sizeof(u32), sizeof(u64)); |
1563 | size -= sizeof(u32); | |
ce71b9df | 1564 | |
1e1dcd93 | 1565 | entry = perf_trace_buf_alloc(size, NULL, &rctx); |
430ad5a6 | 1566 | if (!entry) |
9802d865 | 1567 | return 0; |
a1a138d0 | 1568 | |
c31ffb3f | 1569 | entry->ip = (unsigned long)tk->rp.kp.addr; |
e09c8614 | 1570 | memset(&entry[1], 0, dsize); |
9178412d | 1571 | store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize); |
1e1dcd93 | 1572 | perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, |
8fd0fbbe | 1573 | head, NULL); |
9802d865 | 1574 | return 0; |
e08d1c65 | 1575 | } |
3da0f180 | 1576 | NOKPROBE_SYMBOL(kprobe_perf_func); |
e08d1c65 MH |
1577 | |
1578 | /* Kretprobe profile handler */ | |
3da0f180 | 1579 | static void |
c31ffb3f | 1580 | kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, |
2b106aab | 1581 | struct pt_regs *regs) |
e08d1c65 | 1582 | { |
e3dc9f89 | 1583 | struct trace_event_call *call = trace_probe_event_call(&tk->tp); |
93ccae7a | 1584 | struct kretprobe_trace_entry_head *entry; |
1c024eca | 1585 | struct hlist_head *head; |
e09c8614 | 1586 | int size, __size, dsize; |
4ed7c92d | 1587 | int rctx; |
e08d1c65 | 1588 | |
e87c6bc3 | 1589 | if (bpf_prog_array_valid(call) && !trace_call_bpf(call, regs)) |
2541517c AS |
1590 | return; |
1591 | ||
288e984e ON |
1592 | head = this_cpu_ptr(call->perf_events); |
1593 | if (hlist_empty(head)) | |
1594 | return; | |
1595 | ||
c31ffb3f NK |
1596 | dsize = __get_data_size(&tk->tp, regs); |
1597 | __size = sizeof(*entry) + tk->tp.size + dsize; | |
74ebb63e MH |
1598 | size = ALIGN(__size + sizeof(u32), sizeof(u64)); |
1599 | size -= sizeof(u32); | |
444a2a3b | 1600 | |
1e1dcd93 | 1601 | entry = perf_trace_buf_alloc(size, NULL, &rctx); |
430ad5a6 | 1602 | if (!entry) |
1e12a4a7 | 1603 | return; |
e08d1c65 | 1604 | |
c31ffb3f | 1605 | entry->func = (unsigned long)tk->rp.kp.addr; |
73f9b911 | 1606 | entry->ret_ip = get_kretprobe_retaddr(ri); |
9178412d | 1607 | store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize); |
1e1dcd93 | 1608 | perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, |
8fd0fbbe | 1609 | head, NULL); |
e08d1c65 | 1610 | } |
3da0f180 | 1611 | NOKPROBE_SYMBOL(kretprobe_perf_func); |
41bdc4b4 YS |
1612 | |
1613 | int bpf_get_kprobe_info(const struct perf_event *event, u32 *fd_type, | |
1614 | const char **symbol, u64 *probe_offset, | |
3acf8ace JO |
1615 | u64 *probe_addr, unsigned long *missed, |
1616 | bool perf_type_tracepoint) | |
41bdc4b4 YS |
1617 | { |
1618 | const char *pevent = trace_event_name(event->tp_event); | |
1619 | const char *group = event->tp_event->class->system; | |
1620 | struct trace_kprobe *tk; | |
1621 | ||
1622 | if (perf_type_tracepoint) | |
1623 | tk = find_trace_kprobe(pevent, group); | |
1624 | else | |
22d5bd68 | 1625 | tk = trace_kprobe_primary_from_call(event->tp_event); |
41bdc4b4 YS |
1626 | if (!tk) |
1627 | return -EINVAL; | |
1628 | ||
1629 | *fd_type = trace_kprobe_is_return(tk) ? BPF_FD_TYPE_KRETPROBE | |
1630 | : BPF_FD_TYPE_KPROBE; | |
cd3910d0 YS |
1631 | *probe_offset = tk->rp.kp.offset; |
1632 | *probe_addr = kallsyms_show_value(current_cred()) ? | |
1633 | (unsigned long)tk->rp.kp.addr : 0; | |
1634 | *symbol = tk->symbol; | |
3acf8ace JO |
1635 | if (missed) |
1636 | *missed = trace_kprobe_missed(tk); | |
41bdc4b4 YS |
1637 | return 0; |
1638 | } | |
07b139c8 | 1639 | #endif /* CONFIG_PERF_EVENTS */ |
50d78056 | 1640 | |
3fe3d619 ON |
1641 | /* |
1642 | * called by perf_trace_init() or __ftrace_set_clr_event() under event_mutex. | |
1643 | * | |
1644 | * kprobe_trace_self_tests_init() does enable_trace_probe/disable_trace_probe | |
1645 | * lockless, but we can't race with this __init function. | |
1646 | */ | |
2425bcb9 | 1647 | static int kprobe_register(struct trace_event_call *event, |
fbc1963d | 1648 | enum trace_reg type, void *data) |
2239291a | 1649 | { |
7f1d2f82 | 1650 | struct trace_event_file *file = data; |
1538f888 | 1651 | |
2239291a SR |
1652 | switch (type) { |
1653 | case TRACE_REG_REGISTER: | |
60d53e2c | 1654 | return enable_trace_kprobe(event, file); |
2239291a | 1655 | case TRACE_REG_UNREGISTER: |
60d53e2c | 1656 | return disable_trace_kprobe(event, file); |
2239291a SR |
1657 | |
1658 | #ifdef CONFIG_PERF_EVENTS | |
1659 | case TRACE_REG_PERF_REGISTER: | |
60d53e2c | 1660 | return enable_trace_kprobe(event, NULL); |
2239291a | 1661 | case TRACE_REG_PERF_UNREGISTER: |
60d53e2c | 1662 | return disable_trace_kprobe(event, NULL); |
ceec0b6f JO |
1663 | case TRACE_REG_PERF_OPEN: |
1664 | case TRACE_REG_PERF_CLOSE: | |
489c75c3 JO |
1665 | case TRACE_REG_PERF_ADD: |
1666 | case TRACE_REG_PERF_DEL: | |
ceec0b6f | 1667 | return 0; |
2239291a SR |
1668 | #endif |
1669 | } | |
1670 | return 0; | |
1671 | } | |
50d78056 | 1672 | |
3da0f180 | 1673 | static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs) |
50d78056 | 1674 | { |
c31ffb3f | 1675 | struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp); |
9802d865 | 1676 | int ret = 0; |
e08d1c65 | 1677 | |
a7636d9e | 1678 | raw_cpu_inc(*tk->nhit); |
48182bd2 | 1679 | |
747774d6 | 1680 | if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE)) |
c31ffb3f | 1681 | kprobe_trace_func(tk, regs); |
07b139c8 | 1682 | #ifdef CONFIG_PERF_EVENTS |
747774d6 | 1683 | if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE)) |
9802d865 | 1684 | ret = kprobe_perf_func(tk, regs); |
07b139c8 | 1685 | #endif |
9802d865 | 1686 | return ret; |
50d78056 | 1687 | } |
3da0f180 | 1688 | NOKPROBE_SYMBOL(kprobe_dispatcher); |
50d78056 | 1689 | |
3da0f180 MH |
1690 | static int |
1691 | kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs) | |
50d78056 | 1692 | { |
d741bf41 | 1693 | struct kretprobe *rp = get_kretprobe(ri); |
cc72b720 MHG |
1694 | struct trace_kprobe *tk; |
1695 | ||
1696 | /* | |
1697 | * There is a small chance that get_kretprobe(ri) returns NULL when | |
1698 | * the kretprobe is unregister on another CPU between kretprobe's | |
1699 | * trampoline_handler and this function. | |
1700 | */ | |
1701 | if (unlikely(!rp)) | |
1702 | return 0; | |
50d78056 | 1703 | |
cc72b720 | 1704 | tk = container_of(rp, struct trace_kprobe, rp); |
a7636d9e | 1705 | raw_cpu_inc(*tk->nhit); |
48182bd2 | 1706 | |
747774d6 | 1707 | if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE)) |
c31ffb3f | 1708 | kretprobe_trace_func(tk, ri, regs); |
07b139c8 | 1709 | #ifdef CONFIG_PERF_EVENTS |
747774d6 | 1710 | if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE)) |
c31ffb3f | 1711 | kretprobe_perf_func(tk, ri, regs); |
07b139c8 | 1712 | #endif |
f2cc020d | 1713 | return 0; /* We don't tweak kernel, so just return 0 */ |
50d78056 | 1714 | } |
3da0f180 | 1715 | NOKPROBE_SYMBOL(kretprobe_dispatcher); |
e08d1c65 | 1716 | |
a9a57763 SR |
1717 | static struct trace_event_functions kretprobe_funcs = { |
1718 | .trace = print_kretprobe_event | |
1719 | }; | |
1720 | ||
1721 | static struct trace_event_functions kprobe_funcs = { | |
1722 | .trace = print_kprobe_event | |
1723 | }; | |
1724 | ||
04ae87a5 PZ |
1725 | static struct trace_event_fields kretprobe_fields_array[] = { |
1726 | { .type = TRACE_FUNCTION_TYPE, | |
1727 | .define_fields = kretprobe_event_define_fields }, | |
1728 | {} | |
1729 | }; | |
1730 | ||
1731 | static struct trace_event_fields kprobe_fields_array[] = { | |
1732 | { .type = TRACE_FUNCTION_TYPE, | |
1733 | .define_fields = kprobe_event_define_fields }, | |
1734 | {} | |
1735 | }; | |
1736 | ||
e3dc9f89 | 1737 | static inline void init_trace_event_call(struct trace_kprobe *tk) |
413d37d1 | 1738 | { |
e3dc9f89 MH |
1739 | struct trace_event_call *call = trace_probe_event_call(&tk->tp); |
1740 | ||
c31ffb3f | 1741 | if (trace_kprobe_is_return(tk)) { |
80decc70 | 1742 | call->event.funcs = &kretprobe_funcs; |
04ae87a5 | 1743 | call->class->fields_array = kretprobe_fields_array; |
413d37d1 | 1744 | } else { |
80decc70 | 1745 | call->event.funcs = &kprobe_funcs; |
04ae87a5 | 1746 | call->class->fields_array = kprobe_fields_array; |
413d37d1 | 1747 | } |
e12f03d7 SL |
1748 | |
1749 | call->flags = TRACE_EVENT_FL_KPROBE; | |
1750 | call->class->reg = kprobe_register; | |
e12f03d7 SL |
1751 | } |
1752 | ||
1753 | static int register_kprobe_event(struct trace_kprobe *tk) | |
1754 | { | |
e3dc9f89 | 1755 | init_trace_event_call(tk); |
f730e0f2 | 1756 | |
46e5376d | 1757 | return trace_probe_register_event_call(&tk->tp); |
413d37d1 MH |
1758 | } |
1759 | ||
c31ffb3f | 1760 | static int unregister_kprobe_event(struct trace_kprobe *tk) |
413d37d1 | 1761 | { |
46e5376d | 1762 | return trace_probe_unregister_event_call(&tk->tp); |
413d37d1 MH |
1763 | } |
1764 | ||
e12f03d7 | 1765 | #ifdef CONFIG_PERF_EVENTS |
b022f0c7 | 1766 | |
e12f03d7 SL |
1767 | /* create a trace_kprobe, but don't add it to global lists */ |
1768 | struct trace_event_call * | |
1769 | create_local_trace_kprobe(char *func, void *addr, unsigned long offs, | |
1770 | bool is_return) | |
1771 | { | |
007517a0 | 1772 | enum probe_print_type ptype; |
e12f03d7 SL |
1773 | struct trace_kprobe *tk; |
1774 | int ret; | |
1775 | char *event; | |
1776 | ||
b022f0c7 FL |
1777 | if (func) { |
1778 | unsigned int count; | |
1779 | ||
1780 | count = number_of_same_symbols(func); | |
1781 | if (count > 1) | |
1782 | /* | |
1783 | * Users should use addr to remove the ambiguity of | |
1784 | * using func only. | |
1785 | */ | |
1786 | return ERR_PTR(-EADDRNOTAVAIL); | |
1787 | else if (count == 0) | |
1788 | /* | |
1789 | * We can return ENOENT earlier than when register the | |
1790 | * kprobe. | |
1791 | */ | |
1792 | return ERR_PTR(-ENOENT); | |
1793 | } | |
1794 | ||
e12f03d7 | 1795 | /* |
6212dd29 | 1796 | * local trace_kprobes are not added to dyn_event, so they are never |
e12f03d7 SL |
1797 | * searched in find_trace_kprobe(). Therefore, there is no concern of |
1798 | * duplicated name here. | |
1799 | */ | |
1800 | event = func ? func : "DUMMY_EVENT"; | |
1801 | ||
1802 | tk = alloc_trace_kprobe(KPROBE_EVENT_SYSTEM, event, (void *)addr, func, | |
1803 | offs, 0 /* maxactive */, 0 /* nargs */, | |
1804 | is_return); | |
1805 | ||
1806 | if (IS_ERR(tk)) { | |
1807 | pr_info("Failed to allocate trace_probe.(%d)\n", | |
1808 | (int)PTR_ERR(tk)); | |
1809 | return ERR_CAST(tk); | |
1810 | } | |
1811 | ||
e3dc9f89 | 1812 | init_trace_event_call(tk); |
e12f03d7 | 1813 | |
007517a0 SRV |
1814 | ptype = trace_kprobe_is_return(tk) ? |
1815 | PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL; | |
1816 | if (traceprobe_set_print_fmt(&tk->tp, ptype) < 0) { | |
e12f03d7 SL |
1817 | ret = -ENOMEM; |
1818 | goto error; | |
1819 | } | |
1820 | ||
1821 | ret = __register_trace_kprobe(tk); | |
f730e0f2 | 1822 | if (ret < 0) |
e12f03d7 SL |
1823 | goto error; |
1824 | ||
e3dc9f89 | 1825 | return trace_probe_event_call(&tk->tp); |
e12f03d7 SL |
1826 | error: |
1827 | free_trace_kprobe(tk); | |
1828 | return ERR_PTR(ret); | |
1829 | } | |
1830 | ||
1831 | void destroy_local_trace_kprobe(struct trace_event_call *event_call) | |
1832 | { | |
1833 | struct trace_kprobe *tk; | |
1834 | ||
60d53e2c MH |
1835 | tk = trace_kprobe_primary_from_call(event_call); |
1836 | if (unlikely(!tk)) | |
1837 | return; | |
e12f03d7 SL |
1838 | |
1839 | if (trace_probe_is_enabled(&tk->tp)) { | |
1840 | WARN_ON(1); | |
1841 | return; | |
1842 | } | |
1843 | ||
1844 | __unregister_trace_kprobe(tk); | |
0fc8c358 | 1845 | |
e12f03d7 SL |
1846 | free_trace_kprobe(tk); |
1847 | } | |
1848 | #endif /* CONFIG_PERF_EVENTS */ | |
1849 | ||
970988e1 MH |
1850 | static __init void enable_boot_kprobe_events(void) |
1851 | { | |
1852 | struct trace_array *tr = top_trace_array(); | |
1853 | struct trace_event_file *file; | |
1854 | struct trace_kprobe *tk; | |
1855 | struct dyn_event *pos; | |
1856 | ||
1857 | mutex_lock(&event_mutex); | |
1858 | for_each_trace_kprobe(tk, pos) { | |
1859 | list_for_each_entry(file, &tr->events, list) | |
e3dc9f89 | 1860 | if (file->event_call == trace_probe_event_call(&tk->tp)) |
970988e1 MH |
1861 | trace_event_enable_disable(file, 1, 0); |
1862 | } | |
1863 | mutex_unlock(&event_mutex); | |
1864 | } | |
1865 | ||
1866 | static __init void setup_boot_kprobe_events(void) | |
1867 | { | |
1868 | char *p, *cmd = kprobe_boot_events_buf; | |
1869 | int ret; | |
1870 | ||
1871 | strreplace(kprobe_boot_events_buf, ',', ' '); | |
1872 | ||
1873 | while (cmd && *cmd != '\0') { | |
1874 | p = strchr(cmd, ';'); | |
1875 | if (p) | |
1876 | *p++ = '\0'; | |
1877 | ||
d262271d | 1878 | ret = create_or_delete_trace_kprobe(cmd); |
970988e1 MH |
1879 | if (ret) |
1880 | pr_warn("Failed to add event(%d): %s\n", ret, cmd); | |
1881 | ||
1882 | cmd = p; | |
1883 | } | |
1884 | ||
1885 | enable_boot_kprobe_events(); | |
1886 | } | |
1887 | ||
d8d4c6d0 | 1888 | /* |
ba0fbfbb MH |
1889 | * Register dynevent at core_initcall. This allows kernel to setup kprobe |
1890 | * events in postcore_initcall without tracefs. | |
d8d4c6d0 MH |
1891 | */ |
1892 | static __init int init_kprobe_trace_early(void) | |
413d37d1 | 1893 | { |
6212dd29 MH |
1894 | int ret; |
1895 | ||
1896 | ret = dyn_event_register(&trace_kprobe_ops); | |
1897 | if (ret) | |
1898 | return ret; | |
413d37d1 | 1899 | |
c31ffb3f | 1900 | if (register_module_notifier(&trace_kprobe_module_nb)) |
61424318 MH |
1901 | return -EINVAL; |
1902 | ||
d8d4c6d0 MH |
1903 | return 0; |
1904 | } | |
ba0fbfbb | 1905 | core_initcall(init_kprobe_trace_early); |
d8d4c6d0 MH |
1906 | |
1907 | /* Make a tracefs interface for controlling probe points */ | |
1908 | static __init int init_kprobe_trace(void) | |
1909 | { | |
22c36b18 | 1910 | int ret; |
d8d4c6d0 | 1911 | |
22c36b18 WY |
1912 | ret = tracing_init_dentry(); |
1913 | if (ret) | |
413d37d1 MH |
1914 | return 0; |
1915 | ||
cd7e7bd5 | 1916 | /* Event list interface */ |
e4931b82 YW |
1917 | trace_create_file("kprobe_events", TRACE_MODE_WRITE, |
1918 | NULL, NULL, &kprobe_events_ops); | |
cd7e7bd5 MH |
1919 | |
1920 | /* Profile interface */ | |
e4931b82 YW |
1921 | trace_create_file("kprobe_profile", TRACE_MODE_READ, |
1922 | NULL, NULL, &kprobe_profile_ops); | |
970988e1 MH |
1923 | |
1924 | setup_boot_kprobe_events(); | |
1925 | ||
413d37d1 MH |
1926 | return 0; |
1927 | } | |
1928 | fs_initcall(init_kprobe_trace); | |
1929 | ||
1930 | ||
1931 | #ifdef CONFIG_FTRACE_STARTUP_TEST | |
26a346f2 | 1932 | static __init struct trace_event_file * |
c31ffb3f | 1933 | find_trace_probe_file(struct trace_kprobe *tk, struct trace_array *tr) |
41a7dd42 | 1934 | { |
7f1d2f82 | 1935 | struct trace_event_file *file; |
41a7dd42 MH |
1936 | |
1937 | list_for_each_entry(file, &tr->events, list) | |
e3dc9f89 | 1938 | if (file->event_call == trace_probe_event_call(&tk->tp)) |
41a7dd42 MH |
1939 | return file; |
1940 | ||
1941 | return NULL; | |
1942 | } | |
1943 | ||
3fe3d619 | 1944 | /* |
c31ffb3f | 1945 | * Nobody but us can call enable_trace_kprobe/disable_trace_kprobe at this |
3fe3d619 ON |
1946 | * stage, we can do this lockless. |
1947 | */ | |
413d37d1 MH |
1948 | static __init int kprobe_trace_self_tests_init(void) |
1949 | { | |
231e36f4 | 1950 | int ret, warn = 0; |
413d37d1 | 1951 | int (*target)(int, int, int, int, int, int); |
c31ffb3f | 1952 | struct trace_kprobe *tk; |
7f1d2f82 | 1953 | struct trace_event_file *file; |
413d37d1 | 1954 | |
748ec3a2 YY |
1955 | if (tracing_is_disabled()) |
1956 | return -ENODEV; | |
1957 | ||
60efe21e | 1958 | if (tracing_selftest_disabled) |
b6399cc7 | 1959 | return 0; |
b6399cc7 | 1960 | |
413d37d1 MH |
1961 | target = kprobe_trace_selftest_target; |
1962 | ||
1963 | pr_info("Testing kprobe tracing: "); | |
1964 | ||
d262271d | 1965 | ret = create_or_delete_trace_kprobe("p:testprobe kprobe_trace_selftest_target $stack $stack0 +0($stack)"); |
231e36f4 | 1966 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1967 | pr_warn("error on probing function entry.\n"); |
231e36f4 MH |
1968 | warn++; |
1969 | } else { | |
1970 | /* Enable trace point */ | |
c31ffb3f NK |
1971 | tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM); |
1972 | if (WARN_ON_ONCE(tk == NULL)) { | |
41a7dd42 | 1973 | pr_warn("error on getting new probe.\n"); |
231e36f4 | 1974 | warn++; |
41a7dd42 | 1975 | } else { |
c31ffb3f | 1976 | file = find_trace_probe_file(tk, top_trace_array()); |
41a7dd42 MH |
1977 | if (WARN_ON_ONCE(file == NULL)) { |
1978 | pr_warn("error on getting probe file.\n"); | |
1979 | warn++; | |
1980 | } else | |
60d53e2c MH |
1981 | enable_trace_kprobe( |
1982 | trace_probe_event_call(&tk->tp), file); | |
41a7dd42 | 1983 | } |
231e36f4 | 1984 | } |
413d37d1 | 1985 | |
d262271d | 1986 | ret = create_or_delete_trace_kprobe("r:testprobe2 kprobe_trace_selftest_target $retval"); |
231e36f4 | 1987 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1988 | pr_warn("error on probing function return.\n"); |
231e36f4 MH |
1989 | warn++; |
1990 | } else { | |
1991 | /* Enable trace point */ | |
c31ffb3f NK |
1992 | tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM); |
1993 | if (WARN_ON_ONCE(tk == NULL)) { | |
41a7dd42 | 1994 | pr_warn("error on getting 2nd new probe.\n"); |
231e36f4 | 1995 | warn++; |
41a7dd42 | 1996 | } else { |
c31ffb3f | 1997 | file = find_trace_probe_file(tk, top_trace_array()); |
41a7dd42 MH |
1998 | if (WARN_ON_ONCE(file == NULL)) { |
1999 | pr_warn("error on getting probe file.\n"); | |
2000 | warn++; | |
2001 | } else | |
60d53e2c MH |
2002 | enable_trace_kprobe( |
2003 | trace_probe_event_call(&tk->tp), file); | |
41a7dd42 | 2004 | } |
231e36f4 MH |
2005 | } |
2006 | ||
2007 | if (warn) | |
2008 | goto end; | |
413d37d1 MH |
2009 | |
2010 | ret = target(1, 2, 3, 4, 5, 6); | |
2011 | ||
d4d7ccc8 MN |
2012 | /* |
2013 | * Not expecting an error here, the check is only to prevent the | |
2014 | * optimizer from removing the call to target() as otherwise there | |
2015 | * are no side-effects and the call is never performed. | |
2016 | */ | |
2017 | if (ret != 21) | |
2018 | warn++; | |
2019 | ||
02ca1521 | 2020 | /* Disable trace points before removing it */ |
c31ffb3f NK |
2021 | tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM); |
2022 | if (WARN_ON_ONCE(tk == NULL)) { | |
41a7dd42 | 2023 | pr_warn("error on getting test probe.\n"); |
02ca1521 | 2024 | warn++; |
41a7dd42 | 2025 | } else { |
d4d7ccc8 MN |
2026 | if (trace_kprobe_nhit(tk) != 1) { |
2027 | pr_warn("incorrect number of testprobe hits\n"); | |
2028 | warn++; | |
2029 | } | |
2030 | ||
c31ffb3f | 2031 | file = find_trace_probe_file(tk, top_trace_array()); |
41a7dd42 MH |
2032 | if (WARN_ON_ONCE(file == NULL)) { |
2033 | pr_warn("error on getting probe file.\n"); | |
2034 | warn++; | |
2035 | } else | |
60d53e2c MH |
2036 | disable_trace_kprobe( |
2037 | trace_probe_event_call(&tk->tp), file); | |
41a7dd42 | 2038 | } |
02ca1521 | 2039 | |
c31ffb3f NK |
2040 | tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM); |
2041 | if (WARN_ON_ONCE(tk == NULL)) { | |
41a7dd42 | 2042 | pr_warn("error on getting 2nd test probe.\n"); |
02ca1521 | 2043 | warn++; |
41a7dd42 | 2044 | } else { |
d4d7ccc8 MN |
2045 | if (trace_kprobe_nhit(tk) != 1) { |
2046 | pr_warn("incorrect number of testprobe2 hits\n"); | |
2047 | warn++; | |
2048 | } | |
2049 | ||
c31ffb3f | 2050 | file = find_trace_probe_file(tk, top_trace_array()); |
41a7dd42 MH |
2051 | if (WARN_ON_ONCE(file == NULL)) { |
2052 | pr_warn("error on getting probe file.\n"); | |
2053 | warn++; | |
2054 | } else | |
60d53e2c MH |
2055 | disable_trace_kprobe( |
2056 | trace_probe_event_call(&tk->tp), file); | |
41a7dd42 | 2057 | } |
02ca1521 | 2058 | |
d262271d | 2059 | ret = create_or_delete_trace_kprobe("-:testprobe"); |
231e36f4 | 2060 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 2061 | pr_warn("error on deleting a probe.\n"); |
231e36f4 MH |
2062 | warn++; |
2063 | } | |
2064 | ||
d262271d | 2065 | ret = create_or_delete_trace_kprobe("-:testprobe2"); |
231e36f4 | 2066 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 2067 | pr_warn("error on deleting a probe.\n"); |
231e36f4 MH |
2068 | warn++; |
2069 | } | |
413d37d1 | 2070 | |
231e36f4 | 2071 | end: |
6212dd29 MH |
2072 | ret = dyn_events_release_all(&trace_kprobe_ops); |
2073 | if (WARN_ON_ONCE(ret)) { | |
2074 | pr_warn("error on cleaning up probes.\n"); | |
2075 | warn++; | |
2076 | } | |
30e7d894 TG |
2077 | /* |
2078 | * Wait for the optimizer work to finish. Otherwise it might fiddle | |
2079 | * with probes in already freed __init text. | |
2080 | */ | |
2081 | wait_for_kprobe_optimizer(); | |
231e36f4 MH |
2082 | if (warn) |
2083 | pr_cont("NG: Some tests are failed. Please check them.\n"); | |
2084 | else | |
2085 | pr_cont("OK\n"); | |
413d37d1 MH |
2086 | return 0; |
2087 | } | |
2088 | ||
2089 | late_initcall(kprobe_trace_self_tests_init); | |
2090 | ||
2091 | #endif |