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 MH |
9 | |
10 | #include <linux/module.h> | |
11 | #include <linux/uaccess.h> | |
b2d09103 | 12 | #include <linux/rculist.h> |
540adea3 | 13 | #include <linux/error-injection.h> |
413d37d1 | 14 | |
970988e1 MH |
15 | #include <asm/setup.h> /* for COMMAND_LINE_SIZE */ |
16 | ||
6212dd29 | 17 | #include "trace_dynevent.h" |
d899926f | 18 | #include "trace_kprobe_selftest.h" |
8ab83f56 | 19 | #include "trace_probe.h" |
53305928 | 20 | #include "trace_probe_tmpl.h" |
1ff511e3 | 21 | |
8ab83f56 | 22 | #define KPROBE_EVENT_SYSTEM "kprobes" |
696ced4f | 23 | #define KRETPROBE_MAXACTIVE_MAX 4096 |
970988e1 MH |
24 | #define MAX_KPROBE_CMDLINE_SIZE 1024 |
25 | ||
26 | /* Kprobe early definition from command line */ | |
27 | static char kprobe_boot_events_buf[COMMAND_LINE_SIZE] __initdata; | |
b6399cc7 | 28 | static bool kprobe_boot_events_enabled __initdata; |
970988e1 MH |
29 | |
30 | static int __init set_kprobe_boot_events(char *str) | |
31 | { | |
32 | strlcpy(kprobe_boot_events_buf, str, COMMAND_LINE_SIZE); | |
33 | return 0; | |
34 | } | |
35 | __setup("kprobe_event=", set_kprobe_boot_events); | |
e09c8614 | 36 | |
6212dd29 MH |
37 | static int trace_kprobe_create(int argc, const char **argv); |
38 | static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev); | |
39 | static int trace_kprobe_release(struct dyn_event *ev); | |
40 | static bool trace_kprobe_is_busy(struct dyn_event *ev); | |
41 | static bool trace_kprobe_match(const char *system, const char *event, | |
30199137 | 42 | int argc, const char **argv, struct dyn_event *ev); |
6212dd29 MH |
43 | |
44 | static struct dyn_event_operations trace_kprobe_ops = { | |
45 | .create = trace_kprobe_create, | |
46 | .show = trace_kprobe_show, | |
47 | .is_busy = trace_kprobe_is_busy, | |
48 | .free = trace_kprobe_release, | |
49 | .match = trace_kprobe_match, | |
50 | }; | |
51 | ||
cede666e | 52 | /* |
77b44d1b | 53 | * Kprobe event core functions |
413d37d1 | 54 | */ |
c31ffb3f | 55 | struct trace_kprobe { |
6212dd29 | 56 | struct dyn_event devent; |
4a846b44 | 57 | struct kretprobe rp; /* Use rp.kp for kprobe use */ |
a7636d9e | 58 | unsigned long __percpu *nhit; |
413d37d1 | 59 | const char *symbol; /* symbol name */ |
c31ffb3f | 60 | struct trace_probe tp; |
413d37d1 MH |
61 | }; |
62 | ||
6212dd29 MH |
63 | static bool is_trace_kprobe(struct dyn_event *ev) |
64 | { | |
65 | return ev->ops == &trace_kprobe_ops; | |
66 | } | |
67 | ||
68 | static struct trace_kprobe *to_trace_kprobe(struct dyn_event *ev) | |
69 | { | |
70 | return container_of(ev, struct trace_kprobe, devent); | |
71 | } | |
72 | ||
73 | /** | |
74 | * for_each_trace_kprobe - iterate over the trace_kprobe list | |
75 | * @pos: the struct trace_kprobe * for each entry | |
76 | * @dpos: the struct dyn_event * to use as a loop cursor | |
77 | */ | |
78 | #define for_each_trace_kprobe(pos, dpos) \ | |
79 | for_each_dyn_event(dpos) \ | |
80 | if (is_trace_kprobe(dpos) && (pos = to_trace_kprobe(dpos))) | |
81 | ||
c31ffb3f NK |
82 | #define SIZEOF_TRACE_KPROBE(n) \ |
83 | (offsetof(struct trace_kprobe, tp.args) + \ | |
eca0d916 | 84 | (sizeof(struct probe_arg) * (n))) |
a82378d8 | 85 | |
3da0f180 | 86 | static nokprobe_inline bool trace_kprobe_is_return(struct trace_kprobe *tk) |
413d37d1 | 87 | { |
c31ffb3f | 88 | return tk->rp.handler != NULL; |
413d37d1 MH |
89 | } |
90 | ||
3da0f180 | 91 | static nokprobe_inline const char *trace_kprobe_symbol(struct trace_kprobe *tk) |
413d37d1 | 92 | { |
c31ffb3f | 93 | return tk->symbol ? tk->symbol : "unknown"; |
413d37d1 MH |
94 | } |
95 | ||
3da0f180 | 96 | static nokprobe_inline unsigned long trace_kprobe_offset(struct trace_kprobe *tk) |
61424318 | 97 | { |
c31ffb3f | 98 | return tk->rp.kp.offset; |
61424318 MH |
99 | } |
100 | ||
3da0f180 | 101 | static nokprobe_inline bool trace_kprobe_has_gone(struct trace_kprobe *tk) |
61424318 | 102 | { |
c31ffb3f | 103 | return !!(kprobe_gone(&tk->rp.kp)); |
61424318 MH |
104 | } |
105 | ||
3da0f180 | 106 | static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk, |
c31ffb3f | 107 | struct module *mod) |
61424318 MH |
108 | { |
109 | int len = strlen(mod->name); | |
c31ffb3f | 110 | const char *name = trace_kprobe_symbol(tk); |
61424318 MH |
111 | return strncmp(mod->name, name, len) == 0 && name[len] == ':'; |
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'; | |
125 | mutex_lock(&module_mutex); | |
126 | ret = !!find_module(tk->symbol); | |
127 | mutex_unlock(&module_mutex); | |
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 | ||
140 | static bool trace_kprobe_match(const char *system, const char *event, | |
30199137 | 141 | int argc, const char **argv, struct dyn_event *ev) |
6212dd29 MH |
142 | { |
143 | struct trace_kprobe *tk = to_trace_kprobe(ev); | |
144 | ||
b55ce203 MH |
145 | return strcmp(trace_probe_name(&tk->tp), event) == 0 && |
146 | (!system || strcmp(trace_probe_group_name(&tk->tp), system) == 0); | |
6212dd29 MH |
147 | } |
148 | ||
f18f97ac MN |
149 | static nokprobe_inline unsigned long trace_kprobe_nhit(struct trace_kprobe *tk) |
150 | { | |
151 | unsigned long nhit = 0; | |
152 | int cpu; | |
153 | ||
154 | for_each_possible_cpu(cpu) | |
155 | nhit += *per_cpu_ptr(tk->nhit, cpu); | |
156 | ||
157 | return nhit; | |
158 | } | |
159 | ||
715fa2fd MH |
160 | static nokprobe_inline bool trace_kprobe_is_registered(struct trace_kprobe *tk) |
161 | { | |
162 | return !(list_empty(&tk->rp.kp.list) && | |
163 | hlist_unhashed(&tk->rp.kp.hlist)); | |
164 | } | |
165 | ||
6bc6c77c | 166 | /* Return 0 if it fails to find the symbol address */ |
45408c4f MH |
167 | static nokprobe_inline |
168 | unsigned long trace_kprobe_address(struct trace_kprobe *tk) | |
169 | { | |
170 | unsigned long addr; | |
171 | ||
172 | if (tk->symbol) { | |
173 | addr = (unsigned long) | |
174 | kallsyms_lookup_name(trace_kprobe_symbol(tk)); | |
6bc6c77c MH |
175 | if (addr) |
176 | addr += tk->rp.kp.offset; | |
45408c4f MH |
177 | } else { |
178 | addr = (unsigned long)tk->rp.kp.addr; | |
179 | } | |
180 | return addr; | |
181 | } | |
182 | ||
60d53e2c MH |
183 | static nokprobe_inline struct trace_kprobe * |
184 | trace_kprobe_primary_from_call(struct trace_event_call *call) | |
185 | { | |
186 | struct trace_probe *tp; | |
187 | ||
188 | tp = trace_probe_primary_from_call(call); | |
189 | if (WARN_ON_ONCE(!tp)) | |
190 | return NULL; | |
191 | ||
192 | return container_of(tp, struct trace_kprobe, tp); | |
193 | } | |
194 | ||
b4da3340 | 195 | bool trace_kprobe_on_func_entry(struct trace_event_call *call) |
9802d865 | 196 | { |
60d53e2c | 197 | struct trace_kprobe *tk = trace_kprobe_primary_from_call(call); |
b4da3340 | 198 | |
60d53e2c | 199 | return tk ? kprobe_on_func_entry(tk->rp.kp.addr, |
b4da3340 | 200 | tk->rp.kp.addr ? NULL : tk->rp.kp.symbol_name, |
60d53e2c | 201 | tk->rp.kp.addr ? 0 : tk->rp.kp.offset) : false; |
9802d865 JB |
202 | } |
203 | ||
b4da3340 | 204 | bool trace_kprobe_error_injectable(struct trace_event_call *call) |
9802d865 | 205 | { |
60d53e2c | 206 | struct trace_kprobe *tk = trace_kprobe_primary_from_call(call); |
9802d865 | 207 | |
60d53e2c MH |
208 | return tk ? within_error_injection_list(trace_kprobe_address(tk)) : |
209 | false; | |
9802d865 JB |
210 | } |
211 | ||
c31ffb3f NK |
212 | static int register_kprobe_event(struct trace_kprobe *tk); |
213 | static int unregister_kprobe_event(struct trace_kprobe *tk); | |
413d37d1 | 214 | |
50d78056 MH |
215 | static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs); |
216 | static int kretprobe_dispatcher(struct kretprobe_instance *ri, | |
217 | struct pt_regs *regs); | |
218 | ||
455b2899 MH |
219 | static void free_trace_kprobe(struct trace_kprobe *tk) |
220 | { | |
221 | if (tk) { | |
222 | trace_probe_cleanup(&tk->tp); | |
223 | kfree(tk->symbol); | |
224 | free_percpu(tk->nhit); | |
225 | kfree(tk); | |
226 | } | |
227 | } | |
228 | ||
4a846b44 MH |
229 | /* |
230 | * Allocate new trace_probe and initialize it (including kprobes). | |
231 | */ | |
c31ffb3f | 232 | static struct trace_kprobe *alloc_trace_kprobe(const char *group, |
f52487e9 | 233 | const char *event, |
4a846b44 MH |
234 | void *addr, |
235 | const char *symbol, | |
236 | unsigned long offs, | |
696ced4f | 237 | int maxactive, |
3a6b7666 | 238 | int nargs, bool is_return) |
413d37d1 | 239 | { |
c31ffb3f | 240 | struct trace_kprobe *tk; |
6f3cf440 | 241 | int ret = -ENOMEM; |
413d37d1 | 242 | |
c31ffb3f NK |
243 | tk = kzalloc(SIZEOF_TRACE_KPROBE(nargs), GFP_KERNEL); |
244 | if (!tk) | |
6f3cf440 | 245 | return ERR_PTR(ret); |
413d37d1 | 246 | |
a7636d9e MKL |
247 | tk->nhit = alloc_percpu(unsigned long); |
248 | if (!tk->nhit) | |
249 | goto error; | |
250 | ||
413d37d1 | 251 | if (symbol) { |
c31ffb3f NK |
252 | tk->symbol = kstrdup(symbol, GFP_KERNEL); |
253 | if (!tk->symbol) | |
413d37d1 | 254 | goto error; |
c31ffb3f NK |
255 | tk->rp.kp.symbol_name = tk->symbol; |
256 | tk->rp.kp.offset = offs; | |
4a846b44 | 257 | } else |
c31ffb3f | 258 | tk->rp.kp.addr = addr; |
4a846b44 MH |
259 | |
260 | if (is_return) | |
c31ffb3f | 261 | tk->rp.handler = kretprobe_dispatcher; |
4a846b44 | 262 | else |
c31ffb3f | 263 | tk->rp.kp.pre_handler = kprobe_dispatcher; |
4a846b44 | 264 | |
696ced4f | 265 | tk->rp.maxactive = maxactive; |
715fa2fd MH |
266 | INIT_HLIST_NODE(&tk->rp.kp.hlist); |
267 | INIT_LIST_HEAD(&tk->rp.kp.list); | |
696ced4f | 268 | |
455b2899 MH |
269 | ret = trace_probe_init(&tk->tp, event, group); |
270 | if (ret < 0) | |
f52487e9 MH |
271 | goto error; |
272 | ||
6212dd29 | 273 | dyn_event_init(&tk->devent, &trace_kprobe_ops); |
c31ffb3f | 274 | return tk; |
413d37d1 | 275 | error: |
455b2899 | 276 | free_trace_kprobe(tk); |
6f3cf440 | 277 | return ERR_PTR(ret); |
413d37d1 MH |
278 | } |
279 | ||
c31ffb3f NK |
280 | static struct trace_kprobe *find_trace_kprobe(const char *event, |
281 | const char *group) | |
413d37d1 | 282 | { |
6212dd29 | 283 | struct dyn_event *pos; |
c31ffb3f | 284 | struct trace_kprobe *tk; |
413d37d1 | 285 | |
6212dd29 | 286 | for_each_trace_kprobe(tk, pos) |
b55ce203 MH |
287 | if (strcmp(trace_probe_name(&tk->tp), event) == 0 && |
288 | strcmp(trace_probe_group_name(&tk->tp), group) == 0) | |
c31ffb3f | 289 | return tk; |
413d37d1 MH |
290 | return NULL; |
291 | } | |
292 | ||
87107a25 SRV |
293 | static inline int __enable_trace_kprobe(struct trace_kprobe *tk) |
294 | { | |
295 | int ret = 0; | |
296 | ||
715fa2fd | 297 | if (trace_kprobe_is_registered(tk) && !trace_kprobe_has_gone(tk)) { |
87107a25 SRV |
298 | if (trace_kprobe_is_return(tk)) |
299 | ret = enable_kretprobe(&tk->rp); | |
300 | else | |
301 | ret = enable_kprobe(&tk->rp.kp); | |
302 | } | |
303 | ||
304 | return ret; | |
305 | } | |
306 | ||
60d53e2c MH |
307 | static void __disable_trace_kprobe(struct trace_probe *tp) |
308 | { | |
309 | struct trace_probe *pos; | |
310 | struct trace_kprobe *tk; | |
311 | ||
312 | list_for_each_entry(pos, trace_probe_probe_list(tp), list) { | |
313 | tk = container_of(pos, struct trace_kprobe, tp); | |
314 | if (!trace_kprobe_is_registered(tk)) | |
315 | continue; | |
316 | if (trace_kprobe_is_return(tk)) | |
317 | disable_kretprobe(&tk->rp); | |
318 | else | |
319 | disable_kprobe(&tk->rp.kp); | |
320 | } | |
321 | } | |
322 | ||
41a7dd42 MH |
323 | /* |
324 | * Enable trace_probe | |
325 | * if the file is NULL, enable "perf" handler, or enable "trace" handler. | |
326 | */ | |
60d53e2c MH |
327 | static int enable_trace_kprobe(struct trace_event_call *call, |
328 | struct trace_event_file *file) | |
1538f888 | 329 | { |
60d53e2c MH |
330 | struct trace_probe *pos, *tp; |
331 | struct trace_kprobe *tk; | |
332 | bool enabled; | |
1538f888 MH |
333 | int ret = 0; |
334 | ||
60d53e2c MH |
335 | tp = trace_probe_primary_from_call(call); |
336 | if (WARN_ON_ONCE(!tp)) | |
337 | return -ENODEV; | |
338 | enabled = trace_probe_is_enabled(tp); | |
339 | ||
340 | /* This also changes "enabled" state */ | |
41a7dd42 | 341 | if (file) { |
60d53e2c | 342 | ret = trace_probe_add_file(tp, file); |
b5f935ee MH |
343 | if (ret) |
344 | return ret; | |
345 | } else | |
60d53e2c | 346 | trace_probe_set_flag(tp, TP_FLAG_PROFILE); |
41a7dd42 | 347 | |
b5f935ee MH |
348 | if (enabled) |
349 | return 0; | |
87107a25 | 350 | |
60d53e2c MH |
351 | enabled = false; |
352 | list_for_each_entry(pos, trace_probe_probe_list(tp), list) { | |
353 | tk = container_of(pos, struct trace_kprobe, tp); | |
354 | if (trace_kprobe_has_gone(tk)) | |
355 | continue; | |
356 | ret = __enable_trace_kprobe(tk); | |
357 | if (ret) { | |
358 | if (enabled) { | |
359 | __disable_trace_kprobe(tp); | |
360 | enabled = false; | |
361 | } | |
362 | break; | |
363 | } | |
364 | enabled = true; | |
365 | } | |
366 | ||
367 | if (!enabled) { | |
368 | /* No probe is enabled. Roll back */ | |
b5f935ee | 369 | if (file) |
60d53e2c | 370 | trace_probe_remove_file(tp, file); |
b5f935ee | 371 | else |
60d53e2c MH |
372 | trace_probe_clear_flag(tp, TP_FLAG_PROFILE); |
373 | if (!ret) | |
374 | /* Since all probes are gone, this is not available */ | |
375 | ret = -EADDRNOTAVAIL; | |
57ea2a34 | 376 | } |
b5f935ee | 377 | |
1538f888 MH |
378 | return ret; |
379 | } | |
380 | ||
41a7dd42 MH |
381 | /* |
382 | * Disable trace_probe | |
383 | * if the file is NULL, disable "perf" handler, or disable "trace" handler. | |
384 | */ | |
60d53e2c MH |
385 | static int disable_trace_kprobe(struct trace_event_call *call, |
386 | struct trace_event_file *file) | |
1538f888 | 387 | { |
60d53e2c MH |
388 | struct trace_probe *tp; |
389 | ||
390 | tp = trace_probe_primary_from_call(call); | |
391 | if (WARN_ON_ONCE(!tp)) | |
392 | return -ENODEV; | |
41a7dd42 | 393 | |
41a7dd42 | 394 | if (file) { |
b5f935ee MH |
395 | if (!trace_probe_get_file_link(tp, file)) |
396 | return -ENOENT; | |
397 | if (!trace_probe_has_single_file(tp)) | |
b04d52e3 | 398 | goto out; |
747774d6 | 399 | trace_probe_clear_flag(tp, TP_FLAG_TRACE); |
41a7dd42 | 400 | } else |
747774d6 | 401 | trace_probe_clear_flag(tp, TP_FLAG_PROFILE); |
41a7dd42 | 402 | |
60d53e2c MH |
403 | if (!trace_probe_is_enabled(tp)) |
404 | __disable_trace_kprobe(tp); | |
e12f03d7 | 405 | |
3fe3d619 | 406 | out: |
b5f935ee | 407 | if (file) |
a232e270 | 408 | /* |
b5f935ee MH |
409 | * Synchronization is done in below function. For perf event, |
410 | * file == NULL and perf_trace_event_unreg() calls | |
411 | * tracepoint_synchronize_unregister() to ensure synchronize | |
412 | * event. We don't need to care about it. | |
a232e270 | 413 | */ |
b5f935ee | 414 | trace_probe_remove_file(tp, file); |
a232e270 | 415 | |
60d53e2c | 416 | return 0; |
1538f888 MH |
417 | } |
418 | ||
45408c4f MH |
419 | #if defined(CONFIG_KPROBES_ON_FTRACE) && \ |
420 | !defined(CONFIG_KPROBE_EVENTS_ON_NOTRACE) | |
421 | static bool within_notrace_func(struct trace_kprobe *tk) | |
422 | { | |
423 | unsigned long offset, size, addr; | |
424 | ||
425 | addr = trace_kprobe_address(tk); | |
6bc6c77c MH |
426 | if (!addr || !kallsyms_lookup_size_offset(addr, &size, &offset)) |
427 | return false; | |
45408c4f | 428 | |
9161a864 MH |
429 | /* Get the entry address of the target function */ |
430 | addr -= offset; | |
431 | ||
432 | /* | |
433 | * Since ftrace_location_range() does inclusive range check, we need | |
434 | * to subtract 1 byte from the end address. | |
435 | */ | |
436 | return !ftrace_location_range(addr, addr + size - 1); | |
45408c4f MH |
437 | } |
438 | #else | |
439 | #define within_notrace_func(tk) (false) | |
440 | #endif | |
441 | ||
61424318 | 442 | /* Internal register function - just handle k*probes and flags */ |
c31ffb3f | 443 | static int __register_trace_kprobe(struct trace_kprobe *tk) |
413d37d1 | 444 | { |
a6682814 | 445 | int i, ret; |
61424318 | 446 | |
715fa2fd | 447 | if (trace_kprobe_is_registered(tk)) |
61424318 MH |
448 | return -EINVAL; |
449 | ||
45408c4f MH |
450 | if (within_notrace_func(tk)) { |
451 | pr_warn("Could not probe notrace function %s\n", | |
452 | trace_kprobe_symbol(tk)); | |
453 | return -EINVAL; | |
454 | } | |
455 | ||
a6682814 MH |
456 | for (i = 0; i < tk->tp.nr_args; i++) { |
457 | ret = traceprobe_update_arg(&tk->tp.args[i]); | |
458 | if (ret) | |
459 | return ret; | |
460 | } | |
461 | ||
61424318 | 462 | /* Set/clear disabled flag according to tp->flag */ |
c31ffb3f NK |
463 | if (trace_probe_is_enabled(&tk->tp)) |
464 | tk->rp.kp.flags &= ~KPROBE_FLAG_DISABLED; | |
61424318 | 465 | else |
c31ffb3f | 466 | tk->rp.kp.flags |= KPROBE_FLAG_DISABLED; |
61424318 | 467 | |
c31ffb3f NK |
468 | if (trace_kprobe_is_return(tk)) |
469 | ret = register_kretprobe(&tk->rp); | |
413d37d1 | 470 | else |
c31ffb3f | 471 | ret = register_kprobe(&tk->rp.kp); |
61424318 | 472 | |
61424318 MH |
473 | return ret; |
474 | } | |
475 | ||
476 | /* Internal unregister function - just handle k*probes and flags */ | |
c31ffb3f | 477 | static void __unregister_trace_kprobe(struct trace_kprobe *tk) |
61424318 | 478 | { |
715fa2fd | 479 | if (trace_kprobe_is_registered(tk)) { |
c31ffb3f NK |
480 | if (trace_kprobe_is_return(tk)) |
481 | unregister_kretprobe(&tk->rp); | |
61424318 | 482 | else |
c31ffb3f | 483 | unregister_kprobe(&tk->rp.kp); |
715fa2fd MH |
484 | /* Cleanup kprobe for reuse and mark it unregistered */ |
485 | INIT_HLIST_NODE(&tk->rp.kp.hlist); | |
486 | INIT_LIST_HEAD(&tk->rp.kp.list); | |
c31ffb3f NK |
487 | if (tk->rp.kp.symbol_name) |
488 | tk->rp.kp.addr = NULL; | |
61424318 MH |
489 | } |
490 | } | |
491 | ||
6212dd29 | 492 | /* Unregister a trace_probe and probe_event */ |
c31ffb3f | 493 | static int unregister_trace_kprobe(struct trace_kprobe *tk) |
61424318 | 494 | { |
ca89bc07 MH |
495 | /* If other probes are on the event, just unregister kprobe */ |
496 | if (trace_probe_has_sibling(&tk->tp)) | |
497 | goto unreg; | |
498 | ||
02ca1521 | 499 | /* Enabled event can not be unregistered */ |
c31ffb3f | 500 | if (trace_probe_is_enabled(&tk->tp)) |
02ca1521 MH |
501 | return -EBUSY; |
502 | ||
40c32592 | 503 | /* Will fail if probe is being used by ftrace or perf */ |
c31ffb3f | 504 | if (unregister_kprobe_event(tk)) |
40c32592 SRRH |
505 | return -EBUSY; |
506 | ||
ca89bc07 | 507 | unreg: |
c31ffb3f | 508 | __unregister_trace_kprobe(tk); |
6212dd29 | 509 | dyn_event_remove(&tk->devent); |
ca89bc07 | 510 | trace_probe_unlink(&tk->tp); |
02ca1521 MH |
511 | |
512 | return 0; | |
413d37d1 MH |
513 | } |
514 | ||
ca89bc07 MH |
515 | static int append_trace_kprobe(struct trace_kprobe *tk, struct trace_kprobe *to) |
516 | { | |
517 | int ret; | |
518 | ||
519 | /* Append to existing event */ | |
520 | ret = trace_probe_append(&tk->tp, &to->tp); | |
521 | if (ret) | |
522 | return ret; | |
523 | ||
524 | /* Register k*probe */ | |
525 | ret = __register_trace_kprobe(tk); | |
526 | if (ret == -ENOENT && !trace_kprobe_module_exist(tk)) { | |
527 | pr_warn("This probe might be able to register after target module is loaded. Continue.\n"); | |
528 | ret = 0; | |
529 | } | |
530 | ||
531 | if (ret) | |
532 | trace_probe_unlink(&tk->tp); | |
533 | else | |
534 | dyn_event_add(&tk->devent); | |
535 | ||
536 | return ret; | |
537 | } | |
538 | ||
413d37d1 | 539 | /* Register a trace_probe and probe_event */ |
c31ffb3f | 540 | static int register_trace_kprobe(struct trace_kprobe *tk) |
413d37d1 | 541 | { |
c31ffb3f | 542 | struct trace_kprobe *old_tk; |
413d37d1 MH |
543 | int ret; |
544 | ||
6212dd29 | 545 | mutex_lock(&event_mutex); |
413d37d1 | 546 | |
b55ce203 MH |
547 | old_tk = find_trace_kprobe(trace_probe_name(&tk->tp), |
548 | trace_probe_group_name(&tk->tp)); | |
c31ffb3f | 549 | if (old_tk) { |
ca89bc07 MH |
550 | if (trace_kprobe_is_return(tk) != trace_kprobe_is_return(old_tk)) { |
551 | trace_probe_log_set_index(0); | |
552 | trace_probe_log_err(0, DIFF_PROBE_TYPE); | |
553 | ret = -EEXIST; | |
554 | } else { | |
555 | ret = trace_probe_compare_arg_type(&tk->tp, &old_tk->tp); | |
556 | if (ret) { | |
557 | /* Note that argument starts index = 2 */ | |
558 | trace_probe_log_set_index(ret + 1); | |
559 | trace_probe_log_err(0, DIFF_ARG_TYPE); | |
560 | ret = -EEXIST; | |
561 | } else | |
562 | ret = append_trace_kprobe(tk, old_tk); | |
563 | } | |
564 | goto end; | |
2d5e067e | 565 | } |
61424318 MH |
566 | |
567 | /* Register new event */ | |
c31ffb3f | 568 | ret = register_kprobe_event(tk); |
2d5e067e | 569 | if (ret) { |
a395d6a7 | 570 | pr_warn("Failed to register probe event(%d)\n", ret); |
2d5e067e MH |
571 | goto end; |
572 | } | |
573 | ||
61424318 | 574 | /* Register k*probe */ |
c31ffb3f | 575 | ret = __register_trace_kprobe(tk); |
59158ec4 MH |
576 | if (ret == -ENOENT && !trace_kprobe_module_exist(tk)) { |
577 | pr_warn("This probe might be able to register after target module is loaded. Continue.\n"); | |
578 | ret = 0; | |
579 | } | |
580 | ||
61424318 | 581 | if (ret < 0) |
c31ffb3f | 582 | unregister_kprobe_event(tk); |
61424318 | 583 | else |
6212dd29 | 584 | dyn_event_add(&tk->devent); |
61424318 | 585 | |
413d37d1 | 586 | end: |
6212dd29 | 587 | mutex_unlock(&event_mutex); |
413d37d1 MH |
588 | return ret; |
589 | } | |
590 | ||
61424318 | 591 | /* Module notifier call back, checking event on the module */ |
c31ffb3f | 592 | static int trace_kprobe_module_callback(struct notifier_block *nb, |
61424318 MH |
593 | unsigned long val, void *data) |
594 | { | |
595 | struct module *mod = data; | |
6212dd29 | 596 | struct dyn_event *pos; |
c31ffb3f | 597 | struct trace_kprobe *tk; |
61424318 MH |
598 | int ret; |
599 | ||
600 | if (val != MODULE_STATE_COMING) | |
601 | return NOTIFY_DONE; | |
602 | ||
603 | /* Update probes on coming module */ | |
6212dd29 MH |
604 | mutex_lock(&event_mutex); |
605 | for_each_trace_kprobe(tk, pos) { | |
c31ffb3f | 606 | if (trace_kprobe_within_module(tk, mod)) { |
02ca1521 | 607 | /* Don't need to check busy - this should have gone. */ |
c31ffb3f NK |
608 | __unregister_trace_kprobe(tk); |
609 | ret = __register_trace_kprobe(tk); | |
61424318 | 610 | if (ret) |
a395d6a7 | 611 | pr_warn("Failed to re-register probe %s on %s: %d\n", |
b55ce203 | 612 | trace_probe_name(&tk->tp), |
a395d6a7 | 613 | mod->name, ret); |
61424318 MH |
614 | } |
615 | } | |
6212dd29 | 616 | mutex_unlock(&event_mutex); |
61424318 MH |
617 | |
618 | return NOTIFY_DONE; | |
619 | } | |
620 | ||
c31ffb3f NK |
621 | static struct notifier_block trace_kprobe_module_nb = { |
622 | .notifier_call = trace_kprobe_module_callback, | |
61424318 MH |
623 | .priority = 1 /* Invoked after kprobe module callback */ |
624 | }; | |
625 | ||
fca18a47 NR |
626 | /* Convert certain expected symbols into '_' when generating event names */ |
627 | static inline void sanitize_event_name(char *name) | |
628 | { | |
629 | while (*name++ != '\0') | |
630 | if (*name == ':' || *name == '.') | |
631 | *name = '_'; | |
632 | } | |
633 | ||
6212dd29 | 634 | static int trace_kprobe_create(int argc, const char *argv[]) |
413d37d1 MH |
635 | { |
636 | /* | |
637 | * Argument syntax: | |
696ced4f AC |
638 | * - Add kprobe: |
639 | * p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS] | |
640 | * - Add kretprobe: | |
641 | * r[MAXACTIVE][:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS] | |
413d37d1 | 642 | * Fetch args: |
2e06ff63 MH |
643 | * $retval : fetch return value |
644 | * $stack : fetch stack address | |
645 | * $stackN : fetch Nth of stack (N:0-) | |
35abb67d | 646 | * $comm : fetch current task comm |
413d37d1 MH |
647 | * @ADDR : fetch memory at ADDR (ADDR should be in kernel) |
648 | * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol) | |
649 | * %REG : fetch register REG | |
93ccae7a | 650 | * Dereferencing memory fetch: |
413d37d1 | 651 | * +|-offs(ARG) : fetch memory at ARG +|- offs address. |
eca0d916 MH |
652 | * Alias name of args: |
653 | * NAME=FETCHARG : set NAME as alias of FETCHARG. | |
93ccae7a MH |
654 | * Type of args: |
655 | * FETCHARG:TYPE : use TYPE instead of unsigned long. | |
413d37d1 | 656 | */ |
ab105a4f | 657 | struct trace_kprobe *tk = NULL; |
6212dd29 MH |
658 | int i, len, ret = 0; |
659 | bool is_return = false; | |
660 | char *symbol = NULL, *tmp = NULL; | |
661 | const char *event = NULL, *group = KPROBE_EVENT_SYSTEM; | |
696ced4f | 662 | int maxactive = 0; |
c5d343b6 | 663 | long offset = 0; |
413d37d1 | 664 | void *addr = NULL; |
4a846b44 | 665 | char buf[MAX_EVENT_NAME_LEN]; |
a1303af5 | 666 | unsigned int flags = TPARG_FL_KERNEL; |
413d37d1 | 667 | |
8b05a3a7 AR |
668 | switch (argv[0][0]) { |
669 | case 'r': | |
3a6b7666 | 670 | is_return = true; |
a1303af5 | 671 | flags |= TPARG_FL_RETURN; |
8b05a3a7 AR |
672 | break; |
673 | case 'p': | |
674 | break; | |
675 | default: | |
676 | return -ECANCELED; | |
677 | } | |
678 | if (argc < 2) | |
6212dd29 | 679 | return -ECANCELED; |
413d37d1 | 680 | |
ab105a4f MH |
681 | trace_probe_log_init("trace_kprobe", argc, argv); |
682 | ||
696ced4f | 683 | event = strchr(&argv[0][1], ':'); |
6212dd29 | 684 | if (event) |
696ced4f | 685 | event++; |
6212dd29 | 686 | |
287c038c MH |
687 | if (isdigit(argv[0][1])) { |
688 | if (!is_return) { | |
ab105a4f MH |
689 | trace_probe_log_err(1, MAXACT_NO_KPROBE); |
690 | goto parse_error; | |
287c038c | 691 | } |
6212dd29 MH |
692 | if (event) |
693 | len = event - &argv[0][1] - 1; | |
694 | else | |
695 | len = strlen(&argv[0][1]); | |
ab105a4f MH |
696 | if (len > MAX_EVENT_NAME_LEN - 1) { |
697 | trace_probe_log_err(1, BAD_MAXACT); | |
698 | goto parse_error; | |
699 | } | |
6212dd29 MH |
700 | memcpy(buf, &argv[0][1], len); |
701 | buf[len] = '\0'; | |
702 | ret = kstrtouint(buf, 0, &maxactive); | |
287c038c | 703 | if (ret || !maxactive) { |
ab105a4f MH |
704 | trace_probe_log_err(1, BAD_MAXACT); |
705 | goto parse_error; | |
696ced4f AC |
706 | } |
707 | /* kretprobes instances are iterated over via a list. The | |
708 | * maximum should stay reasonable. | |
709 | */ | |
710 | if (maxactive > KRETPROBE_MAXACTIVE_MAX) { | |
ab105a4f MH |
711 | trace_probe_log_err(1, MAXACT_TOO_BIG); |
712 | goto parse_error; | |
696ced4f AC |
713 | } |
714 | } | |
715 | ||
9e52b325 SD |
716 | /* try to parse an address. if that fails, try to read the |
717 | * input as a symbol. */ | |
718 | if (kstrtoul(argv[1], 0, (unsigned long *)&addr)) { | |
ab105a4f | 719 | trace_probe_log_set_index(1); |
6212dd29 | 720 | /* Check whether uprobe event specified */ |
ab105a4f MH |
721 | if (strchr(argv[1], '/') && strchr(argv[1], ':')) { |
722 | ret = -ECANCELED; | |
723 | goto error; | |
724 | } | |
413d37d1 | 725 | /* a symbol specified */ |
6212dd29 MH |
726 | symbol = kstrdup(argv[1], GFP_KERNEL); |
727 | if (!symbol) | |
728 | return -ENOMEM; | |
413d37d1 | 729 | /* TODO: support .init module functions */ |
8ab83f56 | 730 | ret = traceprobe_split_symbol_offset(symbol, &offset); |
c5d343b6 | 731 | if (ret || offset < 0 || offset > UINT_MAX) { |
ab105a4f MH |
732 | trace_probe_log_err(0, BAD_PROBE_ADDR); |
733 | goto parse_error; | |
e63cc239 | 734 | } |
a1303af5 MH |
735 | if (kprobe_on_func_entry(NULL, symbol, offset)) |
736 | flags |= TPARG_FL_FENTRY; | |
737 | if (offset && is_return && !(flags & TPARG_FL_FENTRY)) { | |
ab105a4f MH |
738 | trace_probe_log_err(0, BAD_RETPROBE); |
739 | goto parse_error; | |
e63cc239 | 740 | } |
413d37d1 MH |
741 | } |
742 | ||
ab105a4f | 743 | trace_probe_log_set_index(0); |
6212dd29 | 744 | if (event) { |
ab105a4f MH |
745 | ret = traceprobe_parse_event_name(&event, &group, buf, |
746 | event - argv[0]); | |
6212dd29 | 747 | if (ret) |
ab105a4f | 748 | goto parse_error; |
6212dd29 | 749 | } else { |
4263565d | 750 | /* Make a new event name */ |
4263565d | 751 | if (symbol) |
6f3cf440 | 752 | snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld", |
4263565d MH |
753 | is_return ? 'r' : 'p', symbol, offset); |
754 | else | |
6f3cf440 | 755 | snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p", |
4263565d | 756 | is_return ? 'r' : 'p', addr); |
fca18a47 | 757 | sanitize_event_name(buf); |
4a846b44 MH |
758 | event = buf; |
759 | } | |
6212dd29 MH |
760 | |
761 | /* setup a probe */ | |
696ced4f | 762 | tk = alloc_trace_kprobe(group, event, addr, symbol, offset, maxactive, |
ab105a4f | 763 | argc - 2, is_return); |
c31ffb3f | 764 | if (IS_ERR(tk)) { |
6212dd29 | 765 | ret = PTR_ERR(tk); |
ab105a4f | 766 | /* This must return -ENOMEM, else there is a bug */ |
a039480e | 767 | WARN_ON_ONCE(ret != -ENOMEM); |
ab105a4f | 768 | goto out; /* We know tk is not allocated */ |
e63cc239 | 769 | } |
ab105a4f | 770 | argc -= 2; argv += 2; |
413d37d1 | 771 | |
413d37d1 | 772 | /* parse arguments */ |
a82378d8 | 773 | for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { |
6212dd29 MH |
774 | tmp = kstrdup(argv[i], GFP_KERNEL); |
775 | if (!tmp) { | |
ba8665d7 | 776 | ret = -ENOMEM; |
413d37d1 MH |
777 | goto error; |
778 | } | |
da34634f | 779 | |
ab105a4f | 780 | trace_probe_log_set_index(i + 2); |
6212dd29 MH |
781 | ret = traceprobe_parse_probe_arg(&tk->tp, i, tmp, flags); |
782 | kfree(tmp); | |
d00bbea9 | 783 | if (ret) |
ab105a4f | 784 | goto error; /* This can be -ENOMEM */ |
413d37d1 | 785 | } |
413d37d1 | 786 | |
f730e0f2 MH |
787 | ret = traceprobe_set_print_fmt(&tk->tp, is_return); |
788 | if (ret < 0) | |
789 | goto error; | |
790 | ||
c31ffb3f | 791 | ret = register_trace_kprobe(tk); |
ab105a4f MH |
792 | if (ret) { |
793 | trace_probe_log_set_index(1); | |
794 | if (ret == -EILSEQ) | |
795 | trace_probe_log_err(0, BAD_INSN_BNDRY); | |
796 | else if (ret == -ENOENT) | |
797 | trace_probe_log_err(0, BAD_PROBE_ADDR); | |
ca89bc07 | 798 | else if (ret != -ENOMEM && ret != -EEXIST) |
ab105a4f | 799 | trace_probe_log_err(0, FAIL_REG_PROBE); |
413d37d1 | 800 | goto error; |
ab105a4f MH |
801 | } |
802 | ||
6212dd29 | 803 | out: |
ab105a4f | 804 | trace_probe_log_clear(); |
6212dd29 MH |
805 | kfree(symbol); |
806 | return ret; | |
413d37d1 | 807 | |
ab105a4f MH |
808 | parse_error: |
809 | ret = -EINVAL; | |
413d37d1 | 810 | error: |
c31ffb3f | 811 | free_trace_kprobe(tk); |
6212dd29 | 812 | goto out; |
413d37d1 MH |
813 | } |
814 | ||
6212dd29 | 815 | static int create_or_delete_trace_kprobe(int argc, char **argv) |
413d37d1 | 816 | { |
6212dd29 | 817 | int ret; |
02ca1521 | 818 | |
6212dd29 MH |
819 | if (argv[0][0] == '-') |
820 | return dyn_event_release(argc, argv, &trace_kprobe_ops); | |
413d37d1 | 821 | |
6212dd29 MH |
822 | ret = trace_kprobe_create(argc, (const char **)argv); |
823 | return ret == -ECANCELED ? -EINVAL : ret; | |
413d37d1 MH |
824 | } |
825 | ||
6212dd29 | 826 | static int trace_kprobe_release(struct dyn_event *ev) |
413d37d1 | 827 | { |
6212dd29 MH |
828 | struct trace_kprobe *tk = to_trace_kprobe(ev); |
829 | int ret = unregister_trace_kprobe(tk); | |
413d37d1 | 830 | |
6212dd29 MH |
831 | if (!ret) |
832 | free_trace_kprobe(tk); | |
833 | return ret; | |
413d37d1 MH |
834 | } |
835 | ||
6212dd29 | 836 | static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev) |
413d37d1 | 837 | { |
6212dd29 | 838 | struct trace_kprobe *tk = to_trace_kprobe(ev); |
93ccae7a | 839 | int i; |
413d37d1 | 840 | |
fa6f0cc7 | 841 | seq_putc(m, trace_kprobe_is_return(tk) ? 'r' : 'p'); |
b55ce203 MH |
842 | seq_printf(m, ":%s/%s", trace_probe_group_name(&tk->tp), |
843 | trace_probe_name(&tk->tp)); | |
413d37d1 | 844 | |
c31ffb3f NK |
845 | if (!tk->symbol) |
846 | seq_printf(m, " 0x%p", tk->rp.kp.addr); | |
847 | else if (tk->rp.kp.offset) | |
848 | seq_printf(m, " %s+%u", trace_kprobe_symbol(tk), | |
849 | tk->rp.kp.offset); | |
413d37d1 | 850 | else |
c31ffb3f | 851 | seq_printf(m, " %s", trace_kprobe_symbol(tk)); |
413d37d1 | 852 | |
c31ffb3f NK |
853 | for (i = 0; i < tk->tp.nr_args; i++) |
854 | seq_printf(m, " %s=%s", tk->tp.args[i].name, tk->tp.args[i].comm); | |
fa6f0cc7 | 855 | seq_putc(m, '\n'); |
93ccae7a | 856 | |
413d37d1 MH |
857 | return 0; |
858 | } | |
859 | ||
6212dd29 MH |
860 | static int probes_seq_show(struct seq_file *m, void *v) |
861 | { | |
862 | struct dyn_event *ev = v; | |
863 | ||
864 | if (!is_trace_kprobe(ev)) | |
865 | return 0; | |
866 | ||
867 | return trace_kprobe_show(m, ev); | |
868 | } | |
869 | ||
413d37d1 | 870 | static const struct seq_operations probes_seq_op = { |
6212dd29 MH |
871 | .start = dyn_event_seq_start, |
872 | .next = dyn_event_seq_next, | |
873 | .stop = dyn_event_seq_stop, | |
413d37d1 MH |
874 | .show = probes_seq_show |
875 | }; | |
876 | ||
877 | static int probes_open(struct inode *inode, struct file *file) | |
878 | { | |
02ca1521 MH |
879 | int ret; |
880 | ||
881 | if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { | |
6212dd29 | 882 | ret = dyn_events_release_all(&trace_kprobe_ops); |
02ca1521 MH |
883 | if (ret < 0) |
884 | return ret; | |
885 | } | |
413d37d1 MH |
886 | |
887 | return seq_open(file, &probes_seq_op); | |
888 | } | |
889 | ||
413d37d1 MH |
890 | static ssize_t probes_write(struct file *file, const char __user *buffer, |
891 | size_t count, loff_t *ppos) | |
892 | { | |
7e465baa | 893 | return trace_parse_run_command(file, buffer, count, ppos, |
6212dd29 | 894 | create_or_delete_trace_kprobe); |
413d37d1 MH |
895 | } |
896 | ||
897 | static const struct file_operations kprobe_events_ops = { | |
898 | .owner = THIS_MODULE, | |
899 | .open = probes_open, | |
900 | .read = seq_read, | |
901 | .llseek = seq_lseek, | |
902 | .release = seq_release, | |
903 | .write = probes_write, | |
904 | }; | |
905 | ||
cd7e7bd5 MH |
906 | /* Probes profiling interfaces */ |
907 | static int probes_profile_seq_show(struct seq_file *m, void *v) | |
908 | { | |
6212dd29 MH |
909 | struct dyn_event *ev = v; |
910 | struct trace_kprobe *tk; | |
cd7e7bd5 | 911 | |
6212dd29 MH |
912 | if (!is_trace_kprobe(ev)) |
913 | return 0; | |
cd7e7bd5 | 914 | |
6212dd29 | 915 | tk = to_trace_kprobe(ev); |
de7b2973 | 916 | seq_printf(m, " %-44s %15lu %15lu\n", |
b55ce203 | 917 | trace_probe_name(&tk->tp), |
f18f97ac | 918 | trace_kprobe_nhit(tk), |
c31ffb3f | 919 | tk->rp.kp.nmissed); |
cd7e7bd5 MH |
920 | |
921 | return 0; | |
922 | } | |
923 | ||
924 | static const struct seq_operations profile_seq_op = { | |
6212dd29 MH |
925 | .start = dyn_event_seq_start, |
926 | .next = dyn_event_seq_next, | |
927 | .stop = dyn_event_seq_stop, | |
cd7e7bd5 MH |
928 | .show = probes_profile_seq_show |
929 | }; | |
930 | ||
931 | static int profile_open(struct inode *inode, struct file *file) | |
932 | { | |
933 | return seq_open(file, &profile_seq_op); | |
934 | } | |
935 | ||
936 | static const struct file_operations kprobe_profile_ops = { | |
937 | .owner = THIS_MODULE, | |
938 | .open = profile_open, | |
939 | .read = seq_read, | |
940 | .llseek = seq_lseek, | |
941 | .release = seq_release, | |
942 | }; | |
943 | ||
53305928 MH |
944 | /* Kprobe specific fetch functions */ |
945 | ||
946 | /* Return the length of string -- including null terminal byte */ | |
9178412d MH |
947 | static nokprobe_inline int |
948 | fetch_store_strlen(unsigned long addr) | |
53305928 | 949 | { |
53305928 MH |
950 | int ret, len = 0; |
951 | u8 c; | |
952 | ||
53305928 | 953 | do { |
49ef5f45 | 954 | ret = probe_kernel_read(&c, (u8 *)addr + len, 1); |
53305928 MH |
955 | len++; |
956 | } while (c && ret == 0 && len < MAX_STRING_SIZE); | |
957 | ||
9178412d | 958 | return (ret < 0) ? ret : len; |
53305928 MH |
959 | } |
960 | ||
88903c46 MH |
961 | /* Return the length of string -- including null terminal byte */ |
962 | static nokprobe_inline int | |
963 | fetch_store_strlen_user(unsigned long addr) | |
964 | { | |
965 | const void __user *uaddr = (__force const void __user *)addr; | |
966 | ||
967 | return strnlen_unsafe_user(uaddr, MAX_STRING_SIZE); | |
968 | } | |
969 | ||
53305928 MH |
970 | /* |
971 | * Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max | |
972 | * length and relative data location. | |
973 | */ | |
9178412d MH |
974 | static nokprobe_inline int |
975 | fetch_store_string(unsigned long addr, void *dest, void *base) | |
53305928 | 976 | { |
9178412d | 977 | int maxlen = get_loc_len(*(u32 *)dest); |
88903c46 | 978 | void *__dest; |
53305928 MH |
979 | long ret; |
980 | ||
9178412d MH |
981 | if (unlikely(!maxlen)) |
982 | return -ENOMEM; | |
88903c46 MH |
983 | |
984 | __dest = get_loc_data(dest, base); | |
985 | ||
53305928 MH |
986 | /* |
987 | * Try to get string again, since the string can be changed while | |
988 | * probing. | |
989 | */ | |
88903c46 MH |
990 | ret = strncpy_from_unsafe(__dest, (void *)addr, maxlen); |
991 | if (ret >= 0) | |
992 | *(u32 *)dest = make_data_loc(ret, __dest - base); | |
993 | ||
994 | return ret; | |
995 | } | |
53305928 | 996 | |
88903c46 MH |
997 | /* |
998 | * Fetch a null-terminated string from user. Caller MUST set *(u32 *)buf | |
999 | * with max length and relative data location. | |
1000 | */ | |
1001 | static nokprobe_inline int | |
1002 | fetch_store_string_user(unsigned long addr, void *dest, void *base) | |
1003 | { | |
1004 | const void __user *uaddr = (__force const void __user *)addr; | |
1005 | int maxlen = get_loc_len(*(u32 *)dest); | |
1006 | void *__dest; | |
1007 | long ret; | |
1008 | ||
1009 | if (unlikely(!maxlen)) | |
1010 | return -ENOMEM; | |
1011 | ||
1012 | __dest = get_loc_data(dest, base); | |
1013 | ||
1014 | ret = strncpy_from_unsafe_user(__dest, uaddr, maxlen); | |
9178412d | 1015 | if (ret >= 0) |
88903c46 MH |
1016 | *(u32 *)dest = make_data_loc(ret, __dest - base); |
1017 | ||
9178412d | 1018 | return ret; |
53305928 MH |
1019 | } |
1020 | ||
9b960a38 MH |
1021 | static nokprobe_inline int |
1022 | probe_mem_read(void *dest, void *src, size_t size) | |
1023 | { | |
1024 | return probe_kernel_read(dest, src, size); | |
1025 | } | |
1026 | ||
e65f7ae7 MH |
1027 | static nokprobe_inline int |
1028 | probe_mem_read_user(void *dest, void *src, size_t size) | |
1029 | { | |
539b75b2 MH |
1030 | const void __user *uaddr = (__force const void __user *)src; |
1031 | ||
1032 | return probe_user_read(dest, uaddr, size); | |
e65f7ae7 MH |
1033 | } |
1034 | ||
53305928 MH |
1035 | /* Note that we don't verify it, since the code does not come from user space */ |
1036 | static int | |
1037 | process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest, | |
9178412d | 1038 | void *base) |
53305928 MH |
1039 | { |
1040 | unsigned long val; | |
53305928 | 1041 | |
a6682814 | 1042 | retry: |
53305928 MH |
1043 | /* 1st stage: get value from context */ |
1044 | switch (code->op) { | |
1045 | case FETCH_OP_REG: | |
1046 | val = regs_get_register(regs, code->param); | |
1047 | break; | |
1048 | case FETCH_OP_STACK: | |
1049 | val = regs_get_kernel_stack_nth(regs, code->param); | |
1050 | break; | |
1051 | case FETCH_OP_STACKP: | |
1052 | val = kernel_stack_pointer(regs); | |
1053 | break; | |
1054 | case FETCH_OP_RETVAL: | |
1055 | val = regs_return_value(regs); | |
1056 | break; | |
1057 | case FETCH_OP_IMM: | |
1058 | val = code->immediate; | |
1059 | break; | |
1060 | case FETCH_OP_COMM: | |
1061 | val = (unsigned long)current->comm; | |
1062 | break; | |
a1303af5 MH |
1063 | #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API |
1064 | case FETCH_OP_ARG: | |
1065 | val = regs_get_kernel_argument(regs, code->param); | |
1066 | break; | |
1067 | #endif | |
a6682814 MH |
1068 | case FETCH_NOP_SYMBOL: /* Ignore a place holder */ |
1069 | code++; | |
1070 | goto retry; | |
53305928 MH |
1071 | default: |
1072 | return -EILSEQ; | |
1073 | } | |
1074 | code++; | |
1075 | ||
9b960a38 | 1076 | return process_fetch_insn_bottom(code, val, dest, base); |
53305928 MH |
1077 | } |
1078 | NOKPROBE_SYMBOL(process_fetch_insn) | |
1079 | ||
413d37d1 | 1080 | /* Kprobe handler */ |
3da0f180 | 1081 | static nokprobe_inline void |
c31ffb3f | 1082 | __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs, |
7f1d2f82 | 1083 | struct trace_event_file *trace_file) |
413d37d1 | 1084 | { |
93ccae7a | 1085 | struct kprobe_trace_entry_head *entry; |
413d37d1 | 1086 | struct ring_buffer_event *event; |
8f8ffe24 | 1087 | struct ring_buffer *buffer; |
e09c8614 | 1088 | int size, dsize, pc; |
413d37d1 | 1089 | unsigned long irq_flags; |
e3dc9f89 | 1090 | struct trace_event_call *call = trace_probe_event_call(&tk->tp); |
413d37d1 | 1091 | |
7f1d2f82 | 1092 | WARN_ON(call != trace_file->event_call); |
41a7dd42 | 1093 | |
09a5059a | 1094 | if (trace_trigger_soft_disabled(trace_file)) |
13a1e4ae | 1095 | return; |
b8820084 | 1096 | |
413d37d1 MH |
1097 | local_save_flags(irq_flags); |
1098 | pc = preempt_count(); | |
1099 | ||
c31ffb3f NK |
1100 | dsize = __get_data_size(&tk->tp, regs); |
1101 | size = sizeof(*entry) + tk->tp.size + dsize; | |
413d37d1 | 1102 | |
7f1d2f82 | 1103 | event = trace_event_buffer_lock_reserve(&buffer, trace_file, |
41a7dd42 MH |
1104 | call->event.type, |
1105 | size, irq_flags, pc); | |
413d37d1 | 1106 | if (!event) |
1e12a4a7 | 1107 | return; |
413d37d1 MH |
1108 | |
1109 | entry = ring_buffer_event_data(event); | |
c31ffb3f | 1110 | entry->ip = (unsigned long)tk->rp.kp.addr; |
9178412d | 1111 | store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize); |
413d37d1 | 1112 | |
7f1d2f82 | 1113 | event_trigger_unlock_commit_regs(trace_file, buffer, event, |
13a1e4ae | 1114 | entry, irq_flags, pc, regs); |
413d37d1 MH |
1115 | } |
1116 | ||
3da0f180 | 1117 | static void |
c31ffb3f | 1118 | kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs) |
41a7dd42 | 1119 | { |
b04d52e3 | 1120 | struct event_file_link *link; |
41a7dd42 | 1121 | |
b5f935ee | 1122 | trace_probe_for_each_link_rcu(link, &tk->tp) |
c31ffb3f | 1123 | __kprobe_trace_func(tk, regs, link->file); |
41a7dd42 | 1124 | } |
3da0f180 | 1125 | NOKPROBE_SYMBOL(kprobe_trace_func); |
41a7dd42 | 1126 | |
413d37d1 | 1127 | /* Kretprobe handler */ |
3da0f180 | 1128 | static nokprobe_inline void |
c31ffb3f | 1129 | __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, |
41a7dd42 | 1130 | struct pt_regs *regs, |
7f1d2f82 | 1131 | struct trace_event_file *trace_file) |
413d37d1 | 1132 | { |
93ccae7a | 1133 | struct kretprobe_trace_entry_head *entry; |
413d37d1 | 1134 | struct ring_buffer_event *event; |
8f8ffe24 | 1135 | struct ring_buffer *buffer; |
e09c8614 | 1136 | int size, pc, dsize; |
413d37d1 | 1137 | unsigned long irq_flags; |
e3dc9f89 | 1138 | struct trace_event_call *call = trace_probe_event_call(&tk->tp); |
413d37d1 | 1139 | |
7f1d2f82 | 1140 | WARN_ON(call != trace_file->event_call); |
41a7dd42 | 1141 | |
09a5059a | 1142 | if (trace_trigger_soft_disabled(trace_file)) |
13a1e4ae | 1143 | return; |
b8820084 | 1144 | |
413d37d1 MH |
1145 | local_save_flags(irq_flags); |
1146 | pc = preempt_count(); | |
1147 | ||
c31ffb3f NK |
1148 | dsize = __get_data_size(&tk->tp, regs); |
1149 | size = sizeof(*entry) + tk->tp.size + dsize; | |
413d37d1 | 1150 | |
7f1d2f82 | 1151 | event = trace_event_buffer_lock_reserve(&buffer, trace_file, |
41a7dd42 MH |
1152 | call->event.type, |
1153 | size, irq_flags, pc); | |
413d37d1 | 1154 | if (!event) |
1e12a4a7 | 1155 | return; |
413d37d1 MH |
1156 | |
1157 | entry = ring_buffer_event_data(event); | |
c31ffb3f | 1158 | entry->func = (unsigned long)tk->rp.kp.addr; |
413d37d1 | 1159 | entry->ret_ip = (unsigned long)ri->ret_addr; |
9178412d | 1160 | store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize); |
413d37d1 | 1161 | |
7f1d2f82 | 1162 | event_trigger_unlock_commit_regs(trace_file, buffer, event, |
13a1e4ae | 1163 | entry, irq_flags, pc, regs); |
413d37d1 MH |
1164 | } |
1165 | ||
3da0f180 | 1166 | static void |
c31ffb3f | 1167 | kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, |
41a7dd42 MH |
1168 | struct pt_regs *regs) |
1169 | { | |
b04d52e3 | 1170 | struct event_file_link *link; |
41a7dd42 | 1171 | |
b5f935ee | 1172 | trace_probe_for_each_link_rcu(link, &tk->tp) |
c31ffb3f | 1173 | __kretprobe_trace_func(tk, ri, regs, link->file); |
41a7dd42 | 1174 | } |
3da0f180 | 1175 | NOKPROBE_SYMBOL(kretprobe_trace_func); |
41a7dd42 | 1176 | |
413d37d1 | 1177 | /* Event entry printers */ |
b62fdd97 | 1178 | static enum print_line_t |
a9a57763 SR |
1179 | print_kprobe_event(struct trace_iterator *iter, int flags, |
1180 | struct trace_event *event) | |
413d37d1 | 1181 | { |
93ccae7a | 1182 | struct kprobe_trace_entry_head *field; |
413d37d1 | 1183 | struct trace_seq *s = &iter->seq; |
eca0d916 | 1184 | struct trace_probe *tp; |
413d37d1 | 1185 | |
93ccae7a | 1186 | field = (struct kprobe_trace_entry_head *)iter->ent; |
60d53e2c MH |
1187 | tp = trace_probe_primary_from_call( |
1188 | container_of(event, struct trace_event_call, event)); | |
1189 | if (WARN_ON_ONCE(!tp)) | |
1190 | goto out; | |
413d37d1 | 1191 | |
b55ce203 | 1192 | trace_seq_printf(s, "%s: (", trace_probe_name(tp)); |
6e9f23d1 | 1193 | |
413d37d1 | 1194 | if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET)) |
85224da0 | 1195 | goto out; |
413d37d1 | 1196 | |
85224da0 | 1197 | trace_seq_putc(s, ')'); |
413d37d1 | 1198 | |
56de7630 MH |
1199 | if (print_probe_args(s, tp->args, tp->nr_args, |
1200 | (u8 *)&field[1], field) < 0) | |
1201 | goto out; | |
413d37d1 | 1202 | |
85224da0 SRRH |
1203 | trace_seq_putc(s, '\n'); |
1204 | out: | |
1205 | return trace_handle_return(s); | |
413d37d1 MH |
1206 | } |
1207 | ||
b62fdd97 | 1208 | static enum print_line_t |
a9a57763 SR |
1209 | print_kretprobe_event(struct trace_iterator *iter, int flags, |
1210 | struct trace_event *event) | |
413d37d1 | 1211 | { |
93ccae7a | 1212 | struct kretprobe_trace_entry_head *field; |
413d37d1 | 1213 | struct trace_seq *s = &iter->seq; |
eca0d916 | 1214 | struct trace_probe *tp; |
413d37d1 | 1215 | |
93ccae7a | 1216 | field = (struct kretprobe_trace_entry_head *)iter->ent; |
60d53e2c MH |
1217 | tp = trace_probe_primary_from_call( |
1218 | container_of(event, struct trace_event_call, event)); | |
1219 | if (WARN_ON_ONCE(!tp)) | |
1220 | goto out; | |
413d37d1 | 1221 | |
b55ce203 | 1222 | trace_seq_printf(s, "%s: (", trace_probe_name(tp)); |
6e9f23d1 | 1223 | |
413d37d1 | 1224 | if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET)) |
85224da0 | 1225 | goto out; |
413d37d1 | 1226 | |
85224da0 | 1227 | trace_seq_puts(s, " <- "); |
413d37d1 MH |
1228 | |
1229 | if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET)) | |
85224da0 | 1230 | goto out; |
413d37d1 | 1231 | |
85224da0 | 1232 | trace_seq_putc(s, ')'); |
413d37d1 | 1233 | |
56de7630 MH |
1234 | if (print_probe_args(s, tp->args, tp->nr_args, |
1235 | (u8 *)&field[1], field) < 0) | |
1236 | goto out; | |
413d37d1 | 1237 | |
85224da0 | 1238 | trace_seq_putc(s, '\n'); |
413d37d1 | 1239 | |
85224da0 SRRH |
1240 | out: |
1241 | return trace_handle_return(s); | |
413d37d1 MH |
1242 | } |
1243 | ||
413d37d1 | 1244 | |
2425bcb9 | 1245 | static int kprobe_event_define_fields(struct trace_event_call *event_call) |
413d37d1 | 1246 | { |
eeb07b06 | 1247 | int ret; |
93ccae7a | 1248 | struct kprobe_trace_entry_head field; |
60d53e2c MH |
1249 | struct trace_probe *tp; |
1250 | ||
1251 | tp = trace_probe_primary_from_call(event_call); | |
1252 | if (WARN_ON_ONCE(!tp)) | |
1253 | return -ENOENT; | |
413d37d1 | 1254 | |
a703d946 | 1255 | DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0); |
c31ffb3f | 1256 | |
60d53e2c | 1257 | return traceprobe_define_arg_fields(event_call, sizeof(field), tp); |
413d37d1 MH |
1258 | } |
1259 | ||
2425bcb9 | 1260 | static int kretprobe_event_define_fields(struct trace_event_call *event_call) |
413d37d1 | 1261 | { |
eeb07b06 | 1262 | int ret; |
93ccae7a | 1263 | struct kretprobe_trace_entry_head field; |
60d53e2c MH |
1264 | struct trace_probe *tp; |
1265 | ||
1266 | tp = trace_probe_primary_from_call(event_call); | |
1267 | if (WARN_ON_ONCE(!tp)) | |
1268 | return -ENOENT; | |
413d37d1 | 1269 | |
a703d946 MH |
1270 | DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0); |
1271 | DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0); | |
c31ffb3f | 1272 | |
60d53e2c | 1273 | return traceprobe_define_arg_fields(event_call, sizeof(field), tp); |
413d37d1 MH |
1274 | } |
1275 | ||
07b139c8 | 1276 | #ifdef CONFIG_PERF_EVENTS |
e08d1c65 MH |
1277 | |
1278 | /* Kprobe profile handler */ | |
9802d865 | 1279 | static int |
c31ffb3f | 1280 | kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs) |
e08d1c65 | 1281 | { |
e3dc9f89 | 1282 | struct trace_event_call *call = trace_probe_event_call(&tk->tp); |
93ccae7a | 1283 | struct kprobe_trace_entry_head *entry; |
1c024eca | 1284 | struct hlist_head *head; |
e09c8614 | 1285 | int size, __size, dsize; |
4ed7c92d | 1286 | int rctx; |
e08d1c65 | 1287 | |
9802d865 | 1288 | if (bpf_prog_array_valid(call)) { |
66665ad2 | 1289 | unsigned long orig_ip = instruction_pointer(regs); |
9802d865 JB |
1290 | int ret; |
1291 | ||
1292 | ret = trace_call_bpf(call, regs); | |
1293 | ||
1294 | /* | |
1295 | * We need to check and see if we modified the pc of the | |
cce188bd MH |
1296 | * pt_regs, and if so return 1 so that we don't do the |
1297 | * single stepping. | |
9802d865 | 1298 | */ |
cce188bd | 1299 | if (orig_ip != instruction_pointer(regs)) |
9802d865 | 1300 | return 1; |
9802d865 JB |
1301 | if (!ret) |
1302 | return 0; | |
1303 | } | |
2541517c | 1304 | |
288e984e ON |
1305 | head = this_cpu_ptr(call->perf_events); |
1306 | if (hlist_empty(head)) | |
9802d865 | 1307 | return 0; |
288e984e | 1308 | |
c31ffb3f NK |
1309 | dsize = __get_data_size(&tk->tp, regs); |
1310 | __size = sizeof(*entry) + tk->tp.size + dsize; | |
74ebb63e MH |
1311 | size = ALIGN(__size + sizeof(u32), sizeof(u64)); |
1312 | size -= sizeof(u32); | |
ce71b9df | 1313 | |
1e1dcd93 | 1314 | entry = perf_trace_buf_alloc(size, NULL, &rctx); |
430ad5a6 | 1315 | if (!entry) |
9802d865 | 1316 | return 0; |
a1a138d0 | 1317 | |
c31ffb3f | 1318 | entry->ip = (unsigned long)tk->rp.kp.addr; |
e09c8614 | 1319 | memset(&entry[1], 0, dsize); |
9178412d | 1320 | store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize); |
1e1dcd93 | 1321 | perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, |
8fd0fbbe | 1322 | head, NULL); |
9802d865 | 1323 | return 0; |
e08d1c65 | 1324 | } |
3da0f180 | 1325 | NOKPROBE_SYMBOL(kprobe_perf_func); |
e08d1c65 MH |
1326 | |
1327 | /* Kretprobe profile handler */ | |
3da0f180 | 1328 | static void |
c31ffb3f | 1329 | kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, |
2b106aab | 1330 | struct pt_regs *regs) |
e08d1c65 | 1331 | { |
e3dc9f89 | 1332 | struct trace_event_call *call = trace_probe_event_call(&tk->tp); |
93ccae7a | 1333 | struct kretprobe_trace_entry_head *entry; |
1c024eca | 1334 | struct hlist_head *head; |
e09c8614 | 1335 | int size, __size, dsize; |
4ed7c92d | 1336 | int rctx; |
e08d1c65 | 1337 | |
e87c6bc3 | 1338 | if (bpf_prog_array_valid(call) && !trace_call_bpf(call, regs)) |
2541517c AS |
1339 | return; |
1340 | ||
288e984e ON |
1341 | head = this_cpu_ptr(call->perf_events); |
1342 | if (hlist_empty(head)) | |
1343 | return; | |
1344 | ||
c31ffb3f NK |
1345 | dsize = __get_data_size(&tk->tp, regs); |
1346 | __size = sizeof(*entry) + tk->tp.size + dsize; | |
74ebb63e MH |
1347 | size = ALIGN(__size + sizeof(u32), sizeof(u64)); |
1348 | size -= sizeof(u32); | |
444a2a3b | 1349 | |
1e1dcd93 | 1350 | entry = perf_trace_buf_alloc(size, NULL, &rctx); |
430ad5a6 | 1351 | if (!entry) |
1e12a4a7 | 1352 | return; |
e08d1c65 | 1353 | |
c31ffb3f | 1354 | entry->func = (unsigned long)tk->rp.kp.addr; |
a1a138d0 | 1355 | entry->ret_ip = (unsigned long)ri->ret_addr; |
9178412d | 1356 | store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize); |
1e1dcd93 | 1357 | perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, |
8fd0fbbe | 1358 | head, NULL); |
e08d1c65 | 1359 | } |
3da0f180 | 1360 | NOKPROBE_SYMBOL(kretprobe_perf_func); |
41bdc4b4 YS |
1361 | |
1362 | int bpf_get_kprobe_info(const struct perf_event *event, u32 *fd_type, | |
1363 | const char **symbol, u64 *probe_offset, | |
1364 | u64 *probe_addr, bool perf_type_tracepoint) | |
1365 | { | |
1366 | const char *pevent = trace_event_name(event->tp_event); | |
1367 | const char *group = event->tp_event->class->system; | |
1368 | struct trace_kprobe *tk; | |
1369 | ||
1370 | if (perf_type_tracepoint) | |
1371 | tk = find_trace_kprobe(pevent, group); | |
1372 | else | |
1373 | tk = event->tp_event->data; | |
1374 | if (!tk) | |
1375 | return -EINVAL; | |
1376 | ||
1377 | *fd_type = trace_kprobe_is_return(tk) ? BPF_FD_TYPE_KRETPROBE | |
1378 | : BPF_FD_TYPE_KPROBE; | |
1379 | if (tk->symbol) { | |
1380 | *symbol = tk->symbol; | |
1381 | *probe_offset = tk->rp.kp.offset; | |
1382 | *probe_addr = 0; | |
1383 | } else { | |
1384 | *symbol = NULL; | |
1385 | *probe_offset = 0; | |
1386 | *probe_addr = (unsigned long)tk->rp.kp.addr; | |
1387 | } | |
1388 | return 0; | |
1389 | } | |
07b139c8 | 1390 | #endif /* CONFIG_PERF_EVENTS */ |
50d78056 | 1391 | |
3fe3d619 ON |
1392 | /* |
1393 | * called by perf_trace_init() or __ftrace_set_clr_event() under event_mutex. | |
1394 | * | |
1395 | * kprobe_trace_self_tests_init() does enable_trace_probe/disable_trace_probe | |
1396 | * lockless, but we can't race with this __init function. | |
1397 | */ | |
2425bcb9 | 1398 | static int kprobe_register(struct trace_event_call *event, |
fbc1963d | 1399 | enum trace_reg type, void *data) |
2239291a | 1400 | { |
7f1d2f82 | 1401 | struct trace_event_file *file = data; |
1538f888 | 1402 | |
2239291a SR |
1403 | switch (type) { |
1404 | case TRACE_REG_REGISTER: | |
60d53e2c | 1405 | return enable_trace_kprobe(event, file); |
2239291a | 1406 | case TRACE_REG_UNREGISTER: |
60d53e2c | 1407 | return disable_trace_kprobe(event, file); |
2239291a SR |
1408 | |
1409 | #ifdef CONFIG_PERF_EVENTS | |
1410 | case TRACE_REG_PERF_REGISTER: | |
60d53e2c | 1411 | return enable_trace_kprobe(event, NULL); |
2239291a | 1412 | case TRACE_REG_PERF_UNREGISTER: |
60d53e2c | 1413 | return disable_trace_kprobe(event, NULL); |
ceec0b6f JO |
1414 | case TRACE_REG_PERF_OPEN: |
1415 | case TRACE_REG_PERF_CLOSE: | |
489c75c3 JO |
1416 | case TRACE_REG_PERF_ADD: |
1417 | case TRACE_REG_PERF_DEL: | |
ceec0b6f | 1418 | return 0; |
2239291a SR |
1419 | #endif |
1420 | } | |
1421 | return 0; | |
1422 | } | |
50d78056 | 1423 | |
3da0f180 | 1424 | static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs) |
50d78056 | 1425 | { |
c31ffb3f | 1426 | struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp); |
9802d865 | 1427 | int ret = 0; |
e08d1c65 | 1428 | |
a7636d9e | 1429 | raw_cpu_inc(*tk->nhit); |
48182bd2 | 1430 | |
747774d6 | 1431 | if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE)) |
c31ffb3f | 1432 | kprobe_trace_func(tk, regs); |
07b139c8 | 1433 | #ifdef CONFIG_PERF_EVENTS |
747774d6 | 1434 | if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE)) |
9802d865 | 1435 | ret = kprobe_perf_func(tk, regs); |
07b139c8 | 1436 | #endif |
9802d865 | 1437 | return ret; |
50d78056 | 1438 | } |
3da0f180 | 1439 | NOKPROBE_SYMBOL(kprobe_dispatcher); |
50d78056 | 1440 | |
3da0f180 MH |
1441 | static int |
1442 | kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs) | |
50d78056 | 1443 | { |
c31ffb3f | 1444 | struct trace_kprobe *tk = container_of(ri->rp, struct trace_kprobe, rp); |
50d78056 | 1445 | |
a7636d9e | 1446 | raw_cpu_inc(*tk->nhit); |
48182bd2 | 1447 | |
747774d6 | 1448 | if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE)) |
c31ffb3f | 1449 | kretprobe_trace_func(tk, ri, regs); |
07b139c8 | 1450 | #ifdef CONFIG_PERF_EVENTS |
747774d6 | 1451 | if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE)) |
c31ffb3f | 1452 | kretprobe_perf_func(tk, ri, regs); |
07b139c8 | 1453 | #endif |
50d78056 MH |
1454 | return 0; /* We don't tweek kernel, so just return 0 */ |
1455 | } | |
3da0f180 | 1456 | NOKPROBE_SYMBOL(kretprobe_dispatcher); |
e08d1c65 | 1457 | |
a9a57763 SR |
1458 | static struct trace_event_functions kretprobe_funcs = { |
1459 | .trace = print_kretprobe_event | |
1460 | }; | |
1461 | ||
1462 | static struct trace_event_functions kprobe_funcs = { | |
1463 | .trace = print_kprobe_event | |
1464 | }; | |
1465 | ||
e3dc9f89 | 1466 | static inline void init_trace_event_call(struct trace_kprobe *tk) |
413d37d1 | 1467 | { |
e3dc9f89 MH |
1468 | struct trace_event_call *call = trace_probe_event_call(&tk->tp); |
1469 | ||
c31ffb3f | 1470 | if (trace_kprobe_is_return(tk)) { |
80decc70 | 1471 | call->event.funcs = &kretprobe_funcs; |
2e33af02 | 1472 | call->class->define_fields = kretprobe_event_define_fields; |
413d37d1 | 1473 | } else { |
80decc70 | 1474 | call->event.funcs = &kprobe_funcs; |
2e33af02 | 1475 | call->class->define_fields = kprobe_event_define_fields; |
413d37d1 | 1476 | } |
e12f03d7 SL |
1477 | |
1478 | call->flags = TRACE_EVENT_FL_KPROBE; | |
1479 | call->class->reg = kprobe_register; | |
e12f03d7 SL |
1480 | } |
1481 | ||
1482 | static int register_kprobe_event(struct trace_kprobe *tk) | |
1483 | { | |
e3dc9f89 | 1484 | init_trace_event_call(tk); |
f730e0f2 | 1485 | |
46e5376d | 1486 | return trace_probe_register_event_call(&tk->tp); |
413d37d1 MH |
1487 | } |
1488 | ||
c31ffb3f | 1489 | static int unregister_kprobe_event(struct trace_kprobe *tk) |
413d37d1 | 1490 | { |
46e5376d | 1491 | return trace_probe_unregister_event_call(&tk->tp); |
413d37d1 MH |
1492 | } |
1493 | ||
e12f03d7 SL |
1494 | #ifdef CONFIG_PERF_EVENTS |
1495 | /* create a trace_kprobe, but don't add it to global lists */ | |
1496 | struct trace_event_call * | |
1497 | create_local_trace_kprobe(char *func, void *addr, unsigned long offs, | |
1498 | bool is_return) | |
1499 | { | |
1500 | struct trace_kprobe *tk; | |
1501 | int ret; | |
1502 | char *event; | |
1503 | ||
1504 | /* | |
6212dd29 | 1505 | * local trace_kprobes are not added to dyn_event, so they are never |
e12f03d7 SL |
1506 | * searched in find_trace_kprobe(). Therefore, there is no concern of |
1507 | * duplicated name here. | |
1508 | */ | |
1509 | event = func ? func : "DUMMY_EVENT"; | |
1510 | ||
1511 | tk = alloc_trace_kprobe(KPROBE_EVENT_SYSTEM, event, (void *)addr, func, | |
1512 | offs, 0 /* maxactive */, 0 /* nargs */, | |
1513 | is_return); | |
1514 | ||
1515 | if (IS_ERR(tk)) { | |
1516 | pr_info("Failed to allocate trace_probe.(%d)\n", | |
1517 | (int)PTR_ERR(tk)); | |
1518 | return ERR_CAST(tk); | |
1519 | } | |
1520 | ||
e3dc9f89 | 1521 | init_trace_event_call(tk); |
e12f03d7 | 1522 | |
0a46c854 | 1523 | if (traceprobe_set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) { |
e12f03d7 SL |
1524 | ret = -ENOMEM; |
1525 | goto error; | |
1526 | } | |
1527 | ||
1528 | ret = __register_trace_kprobe(tk); | |
f730e0f2 | 1529 | if (ret < 0) |
e12f03d7 SL |
1530 | goto error; |
1531 | ||
e3dc9f89 | 1532 | return trace_probe_event_call(&tk->tp); |
e12f03d7 SL |
1533 | error: |
1534 | free_trace_kprobe(tk); | |
1535 | return ERR_PTR(ret); | |
1536 | } | |
1537 | ||
1538 | void destroy_local_trace_kprobe(struct trace_event_call *event_call) | |
1539 | { | |
1540 | struct trace_kprobe *tk; | |
1541 | ||
60d53e2c MH |
1542 | tk = trace_kprobe_primary_from_call(event_call); |
1543 | if (unlikely(!tk)) | |
1544 | return; | |
e12f03d7 SL |
1545 | |
1546 | if (trace_probe_is_enabled(&tk->tp)) { | |
1547 | WARN_ON(1); | |
1548 | return; | |
1549 | } | |
1550 | ||
1551 | __unregister_trace_kprobe(tk); | |
0fc8c358 | 1552 | |
e12f03d7 SL |
1553 | free_trace_kprobe(tk); |
1554 | } | |
1555 | #endif /* CONFIG_PERF_EVENTS */ | |
1556 | ||
970988e1 MH |
1557 | static __init void enable_boot_kprobe_events(void) |
1558 | { | |
1559 | struct trace_array *tr = top_trace_array(); | |
1560 | struct trace_event_file *file; | |
1561 | struct trace_kprobe *tk; | |
1562 | struct dyn_event *pos; | |
1563 | ||
1564 | mutex_lock(&event_mutex); | |
1565 | for_each_trace_kprobe(tk, pos) { | |
1566 | list_for_each_entry(file, &tr->events, list) | |
e3dc9f89 | 1567 | if (file->event_call == trace_probe_event_call(&tk->tp)) |
970988e1 MH |
1568 | trace_event_enable_disable(file, 1, 0); |
1569 | } | |
1570 | mutex_unlock(&event_mutex); | |
1571 | } | |
1572 | ||
1573 | static __init void setup_boot_kprobe_events(void) | |
1574 | { | |
1575 | char *p, *cmd = kprobe_boot_events_buf; | |
1576 | int ret; | |
1577 | ||
1578 | strreplace(kprobe_boot_events_buf, ',', ' '); | |
1579 | ||
1580 | while (cmd && *cmd != '\0') { | |
1581 | p = strchr(cmd, ';'); | |
1582 | if (p) | |
1583 | *p++ = '\0'; | |
1584 | ||
1585 | ret = trace_run_command(cmd, create_or_delete_trace_kprobe); | |
1586 | if (ret) | |
1587 | pr_warn("Failed to add event(%d): %s\n", ret, cmd); | |
b6399cc7 SRV |
1588 | else |
1589 | kprobe_boot_events_enabled = true; | |
970988e1 MH |
1590 | |
1591 | cmd = p; | |
1592 | } | |
1593 | ||
1594 | enable_boot_kprobe_events(); | |
1595 | } | |
1596 | ||
8434dc93 | 1597 | /* Make a tracefs interface for controlling probe points */ |
413d37d1 MH |
1598 | static __init int init_kprobe_trace(void) |
1599 | { | |
1600 | struct dentry *d_tracer; | |
1601 | struct dentry *entry; | |
6212dd29 MH |
1602 | int ret; |
1603 | ||
1604 | ret = dyn_event_register(&trace_kprobe_ops); | |
1605 | if (ret) | |
1606 | return ret; | |
413d37d1 | 1607 | |
c31ffb3f | 1608 | if (register_module_notifier(&trace_kprobe_module_nb)) |
61424318 MH |
1609 | return -EINVAL; |
1610 | ||
413d37d1 | 1611 | d_tracer = tracing_init_dentry(); |
14a5ae40 | 1612 | if (IS_ERR(d_tracer)) |
413d37d1 MH |
1613 | return 0; |
1614 | ||
8434dc93 | 1615 | entry = tracefs_create_file("kprobe_events", 0644, d_tracer, |
413d37d1 MH |
1616 | NULL, &kprobe_events_ops); |
1617 | ||
cd7e7bd5 | 1618 | /* Event list interface */ |
413d37d1 | 1619 | if (!entry) |
a395d6a7 | 1620 | pr_warn("Could not create tracefs 'kprobe_events' entry\n"); |
cd7e7bd5 MH |
1621 | |
1622 | /* Profile interface */ | |
8434dc93 | 1623 | entry = tracefs_create_file("kprobe_profile", 0444, d_tracer, |
cd7e7bd5 MH |
1624 | NULL, &kprobe_profile_ops); |
1625 | ||
1626 | if (!entry) | |
a395d6a7 | 1627 | pr_warn("Could not create tracefs 'kprobe_profile' entry\n"); |
970988e1 MH |
1628 | |
1629 | setup_boot_kprobe_events(); | |
1630 | ||
413d37d1 MH |
1631 | return 0; |
1632 | } | |
1633 | fs_initcall(init_kprobe_trace); | |
1634 | ||
1635 | ||
1636 | #ifdef CONFIG_FTRACE_STARTUP_TEST | |
26a346f2 | 1637 | static __init struct trace_event_file * |
c31ffb3f | 1638 | find_trace_probe_file(struct trace_kprobe *tk, struct trace_array *tr) |
41a7dd42 | 1639 | { |
7f1d2f82 | 1640 | struct trace_event_file *file; |
41a7dd42 MH |
1641 | |
1642 | list_for_each_entry(file, &tr->events, list) | |
e3dc9f89 | 1643 | if (file->event_call == trace_probe_event_call(&tk->tp)) |
41a7dd42 MH |
1644 | return file; |
1645 | ||
1646 | return NULL; | |
1647 | } | |
1648 | ||
3fe3d619 | 1649 | /* |
c31ffb3f | 1650 | * Nobody but us can call enable_trace_kprobe/disable_trace_kprobe at this |
3fe3d619 ON |
1651 | * stage, we can do this lockless. |
1652 | */ | |
413d37d1 MH |
1653 | static __init int kprobe_trace_self_tests_init(void) |
1654 | { | |
231e36f4 | 1655 | int ret, warn = 0; |
413d37d1 | 1656 | int (*target)(int, int, int, int, int, int); |
c31ffb3f | 1657 | struct trace_kprobe *tk; |
7f1d2f82 | 1658 | struct trace_event_file *file; |
413d37d1 | 1659 | |
748ec3a2 YY |
1660 | if (tracing_is_disabled()) |
1661 | return -ENODEV; | |
1662 | ||
b6399cc7 SRV |
1663 | if (kprobe_boot_events_enabled) { |
1664 | pr_info("Skipping kprobe tests due to kprobe_event on cmdline\n"); | |
1665 | return 0; | |
1666 | } | |
1667 | ||
413d37d1 MH |
1668 | target = kprobe_trace_selftest_target; |
1669 | ||
1670 | pr_info("Testing kprobe tracing: "); | |
1671 | ||
6212dd29 MH |
1672 | ret = trace_run_command("p:testprobe kprobe_trace_selftest_target $stack $stack0 +0($stack)", |
1673 | create_or_delete_trace_kprobe); | |
231e36f4 | 1674 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1675 | pr_warn("error on probing function entry.\n"); |
231e36f4 MH |
1676 | warn++; |
1677 | } else { | |
1678 | /* Enable trace point */ | |
c31ffb3f NK |
1679 | tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM); |
1680 | if (WARN_ON_ONCE(tk == NULL)) { | |
41a7dd42 | 1681 | pr_warn("error on getting new probe.\n"); |
231e36f4 | 1682 | warn++; |
41a7dd42 | 1683 | } else { |
c31ffb3f | 1684 | file = find_trace_probe_file(tk, top_trace_array()); |
41a7dd42 MH |
1685 | if (WARN_ON_ONCE(file == NULL)) { |
1686 | pr_warn("error on getting probe file.\n"); | |
1687 | warn++; | |
1688 | } else | |
60d53e2c MH |
1689 | enable_trace_kprobe( |
1690 | trace_probe_event_call(&tk->tp), file); | |
41a7dd42 | 1691 | } |
231e36f4 | 1692 | } |
413d37d1 | 1693 | |
6212dd29 MH |
1694 | ret = trace_run_command("r:testprobe2 kprobe_trace_selftest_target $retval", |
1695 | create_or_delete_trace_kprobe); | |
231e36f4 | 1696 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1697 | pr_warn("error on probing function return.\n"); |
231e36f4 MH |
1698 | warn++; |
1699 | } else { | |
1700 | /* Enable trace point */ | |
c31ffb3f NK |
1701 | tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM); |
1702 | if (WARN_ON_ONCE(tk == NULL)) { | |
41a7dd42 | 1703 | pr_warn("error on getting 2nd new probe.\n"); |
231e36f4 | 1704 | warn++; |
41a7dd42 | 1705 | } else { |
c31ffb3f | 1706 | file = find_trace_probe_file(tk, top_trace_array()); |
41a7dd42 MH |
1707 | if (WARN_ON_ONCE(file == NULL)) { |
1708 | pr_warn("error on getting probe file.\n"); | |
1709 | warn++; | |
1710 | } else | |
60d53e2c MH |
1711 | enable_trace_kprobe( |
1712 | trace_probe_event_call(&tk->tp), file); | |
41a7dd42 | 1713 | } |
231e36f4 MH |
1714 | } |
1715 | ||
1716 | if (warn) | |
1717 | goto end; | |
413d37d1 MH |
1718 | |
1719 | ret = target(1, 2, 3, 4, 5, 6); | |
1720 | ||
d4d7ccc8 MN |
1721 | /* |
1722 | * Not expecting an error here, the check is only to prevent the | |
1723 | * optimizer from removing the call to target() as otherwise there | |
1724 | * are no side-effects and the call is never performed. | |
1725 | */ | |
1726 | if (ret != 21) | |
1727 | warn++; | |
1728 | ||
02ca1521 | 1729 | /* Disable trace points before removing it */ |
c31ffb3f NK |
1730 | tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM); |
1731 | if (WARN_ON_ONCE(tk == NULL)) { | |
41a7dd42 | 1732 | pr_warn("error on getting test probe.\n"); |
02ca1521 | 1733 | warn++; |
41a7dd42 | 1734 | } else { |
d4d7ccc8 MN |
1735 | if (trace_kprobe_nhit(tk) != 1) { |
1736 | pr_warn("incorrect number of testprobe hits\n"); | |
1737 | warn++; | |
1738 | } | |
1739 | ||
c31ffb3f | 1740 | file = find_trace_probe_file(tk, top_trace_array()); |
41a7dd42 MH |
1741 | if (WARN_ON_ONCE(file == NULL)) { |
1742 | pr_warn("error on getting probe file.\n"); | |
1743 | warn++; | |
1744 | } else | |
60d53e2c MH |
1745 | disable_trace_kprobe( |
1746 | trace_probe_event_call(&tk->tp), file); | |
41a7dd42 | 1747 | } |
02ca1521 | 1748 | |
c31ffb3f NK |
1749 | tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM); |
1750 | if (WARN_ON_ONCE(tk == NULL)) { | |
41a7dd42 | 1751 | pr_warn("error on getting 2nd test probe.\n"); |
02ca1521 | 1752 | warn++; |
41a7dd42 | 1753 | } else { |
d4d7ccc8 MN |
1754 | if (trace_kprobe_nhit(tk) != 1) { |
1755 | pr_warn("incorrect number of testprobe2 hits\n"); | |
1756 | warn++; | |
1757 | } | |
1758 | ||
c31ffb3f | 1759 | file = find_trace_probe_file(tk, top_trace_array()); |
41a7dd42 MH |
1760 | if (WARN_ON_ONCE(file == NULL)) { |
1761 | pr_warn("error on getting probe file.\n"); | |
1762 | warn++; | |
1763 | } else | |
60d53e2c MH |
1764 | disable_trace_kprobe( |
1765 | trace_probe_event_call(&tk->tp), file); | |
41a7dd42 | 1766 | } |
02ca1521 | 1767 | |
6212dd29 | 1768 | ret = trace_run_command("-:testprobe", create_or_delete_trace_kprobe); |
231e36f4 | 1769 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1770 | pr_warn("error on deleting a probe.\n"); |
231e36f4 MH |
1771 | warn++; |
1772 | } | |
1773 | ||
6212dd29 | 1774 | ret = trace_run_command("-:testprobe2", create_or_delete_trace_kprobe); |
231e36f4 | 1775 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1776 | pr_warn("error on deleting a probe.\n"); |
231e36f4 MH |
1777 | warn++; |
1778 | } | |
413d37d1 | 1779 | |
231e36f4 | 1780 | end: |
6212dd29 MH |
1781 | ret = dyn_events_release_all(&trace_kprobe_ops); |
1782 | if (WARN_ON_ONCE(ret)) { | |
1783 | pr_warn("error on cleaning up probes.\n"); | |
1784 | warn++; | |
1785 | } | |
30e7d894 TG |
1786 | /* |
1787 | * Wait for the optimizer work to finish. Otherwise it might fiddle | |
1788 | * with probes in already freed __init text. | |
1789 | */ | |
1790 | wait_for_kprobe_optimizer(); | |
231e36f4 MH |
1791 | if (warn) |
1792 | pr_cont("NG: Some tests are failed. Please check them.\n"); | |
1793 | else | |
1794 | pr_cont("OK\n"); | |
413d37d1 MH |
1795 | return 0; |
1796 | } | |
1797 | ||
1798 | late_initcall(kprobe_trace_self_tests_init); | |
1799 | ||
1800 | #endif |