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 | |
6212dd29 | 15 | #include "trace_dynevent.h" |
d899926f | 16 | #include "trace_kprobe_selftest.h" |
8ab83f56 | 17 | #include "trace_probe.h" |
53305928 | 18 | #include "trace_probe_tmpl.h" |
1ff511e3 | 19 | |
8ab83f56 | 20 | #define KPROBE_EVENT_SYSTEM "kprobes" |
696ced4f | 21 | #define KRETPROBE_MAXACTIVE_MAX 4096 |
e09c8614 | 22 | |
6212dd29 MH |
23 | static int trace_kprobe_create(int argc, const char **argv); |
24 | static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev); | |
25 | static int trace_kprobe_release(struct dyn_event *ev); | |
26 | static bool trace_kprobe_is_busy(struct dyn_event *ev); | |
27 | static bool trace_kprobe_match(const char *system, const char *event, | |
28 | struct dyn_event *ev); | |
29 | ||
30 | static struct dyn_event_operations trace_kprobe_ops = { | |
31 | .create = trace_kprobe_create, | |
32 | .show = trace_kprobe_show, | |
33 | .is_busy = trace_kprobe_is_busy, | |
34 | .free = trace_kprobe_release, | |
35 | .match = trace_kprobe_match, | |
36 | }; | |
37 | ||
cede666e | 38 | /* |
77b44d1b | 39 | * Kprobe event core functions |
413d37d1 | 40 | */ |
c31ffb3f | 41 | struct trace_kprobe { |
6212dd29 | 42 | struct dyn_event devent; |
4a846b44 | 43 | struct kretprobe rp; /* Use rp.kp for kprobe use */ |
a7636d9e | 44 | unsigned long __percpu *nhit; |
413d37d1 | 45 | const char *symbol; /* symbol name */ |
c31ffb3f | 46 | struct trace_probe tp; |
413d37d1 MH |
47 | }; |
48 | ||
6212dd29 MH |
49 | static bool is_trace_kprobe(struct dyn_event *ev) |
50 | { | |
51 | return ev->ops == &trace_kprobe_ops; | |
52 | } | |
53 | ||
54 | static struct trace_kprobe *to_trace_kprobe(struct dyn_event *ev) | |
55 | { | |
56 | return container_of(ev, struct trace_kprobe, devent); | |
57 | } | |
58 | ||
59 | /** | |
60 | * for_each_trace_kprobe - iterate over the trace_kprobe list | |
61 | * @pos: the struct trace_kprobe * for each entry | |
62 | * @dpos: the struct dyn_event * to use as a loop cursor | |
63 | */ | |
64 | #define for_each_trace_kprobe(pos, dpos) \ | |
65 | for_each_dyn_event(dpos) \ | |
66 | if (is_trace_kprobe(dpos) && (pos = to_trace_kprobe(dpos))) | |
67 | ||
c31ffb3f NK |
68 | #define SIZEOF_TRACE_KPROBE(n) \ |
69 | (offsetof(struct trace_kprobe, tp.args) + \ | |
eca0d916 | 70 | (sizeof(struct probe_arg) * (n))) |
a82378d8 | 71 | |
3da0f180 | 72 | static nokprobe_inline bool trace_kprobe_is_return(struct trace_kprobe *tk) |
413d37d1 | 73 | { |
c31ffb3f | 74 | return tk->rp.handler != NULL; |
413d37d1 MH |
75 | } |
76 | ||
3da0f180 | 77 | static nokprobe_inline const char *trace_kprobe_symbol(struct trace_kprobe *tk) |
413d37d1 | 78 | { |
c31ffb3f | 79 | return tk->symbol ? tk->symbol : "unknown"; |
413d37d1 MH |
80 | } |
81 | ||
3da0f180 | 82 | static nokprobe_inline unsigned long trace_kprobe_offset(struct trace_kprobe *tk) |
61424318 | 83 | { |
c31ffb3f | 84 | return tk->rp.kp.offset; |
61424318 MH |
85 | } |
86 | ||
3da0f180 | 87 | static nokprobe_inline bool trace_kprobe_has_gone(struct trace_kprobe *tk) |
61424318 | 88 | { |
c31ffb3f | 89 | return !!(kprobe_gone(&tk->rp.kp)); |
61424318 MH |
90 | } |
91 | ||
3da0f180 | 92 | static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk, |
c31ffb3f | 93 | struct module *mod) |
61424318 MH |
94 | { |
95 | int len = strlen(mod->name); | |
c31ffb3f | 96 | const char *name = trace_kprobe_symbol(tk); |
61424318 MH |
97 | return strncmp(mod->name, name, len) == 0 && name[len] == ':'; |
98 | } | |
99 | ||
59158ec4 | 100 | static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk) |
61424318 | 101 | { |
59158ec4 MH |
102 | char *p; |
103 | bool ret; | |
104 | ||
105 | if (!tk->symbol) | |
106 | return false; | |
107 | p = strchr(tk->symbol, ':'); | |
108 | if (!p) | |
109 | return true; | |
110 | *p = '\0'; | |
111 | mutex_lock(&module_mutex); | |
112 | ret = !!find_module(tk->symbol); | |
113 | mutex_unlock(&module_mutex); | |
114 | *p = ':'; | |
115 | ||
116 | return ret; | |
61424318 MH |
117 | } |
118 | ||
6212dd29 MH |
119 | static bool trace_kprobe_is_busy(struct dyn_event *ev) |
120 | { | |
121 | struct trace_kprobe *tk = to_trace_kprobe(ev); | |
122 | ||
123 | return trace_probe_is_enabled(&tk->tp); | |
124 | } | |
125 | ||
126 | static bool trace_kprobe_match(const char *system, const char *event, | |
127 | struct dyn_event *ev) | |
128 | { | |
129 | struct trace_kprobe *tk = to_trace_kprobe(ev); | |
130 | ||
131 | return strcmp(trace_event_name(&tk->tp.call), event) == 0 && | |
132 | (!system || strcmp(tk->tp.call.class->system, system) == 0); | |
133 | } | |
134 | ||
f18f97ac MN |
135 | static nokprobe_inline unsigned long trace_kprobe_nhit(struct trace_kprobe *tk) |
136 | { | |
137 | unsigned long nhit = 0; | |
138 | int cpu; | |
139 | ||
140 | for_each_possible_cpu(cpu) | |
141 | nhit += *per_cpu_ptr(tk->nhit, cpu); | |
142 | ||
143 | return nhit; | |
144 | } | |
145 | ||
6bc6c77c | 146 | /* Return 0 if it fails to find the symbol address */ |
45408c4f MH |
147 | static nokprobe_inline |
148 | unsigned long trace_kprobe_address(struct trace_kprobe *tk) | |
149 | { | |
150 | unsigned long addr; | |
151 | ||
152 | if (tk->symbol) { | |
153 | addr = (unsigned long) | |
154 | kallsyms_lookup_name(trace_kprobe_symbol(tk)); | |
6bc6c77c MH |
155 | if (addr) |
156 | addr += tk->rp.kp.offset; | |
45408c4f MH |
157 | } else { |
158 | addr = (unsigned long)tk->rp.kp.addr; | |
159 | } | |
160 | return addr; | |
161 | } | |
162 | ||
b4da3340 | 163 | bool trace_kprobe_on_func_entry(struct trace_event_call *call) |
9802d865 JB |
164 | { |
165 | struct trace_kprobe *tk = (struct trace_kprobe *)call->data; | |
b4da3340 MH |
166 | |
167 | return kprobe_on_func_entry(tk->rp.kp.addr, | |
168 | tk->rp.kp.addr ? NULL : tk->rp.kp.symbol_name, | |
169 | tk->rp.kp.addr ? 0 : tk->rp.kp.offset); | |
9802d865 JB |
170 | } |
171 | ||
b4da3340 | 172 | bool trace_kprobe_error_injectable(struct trace_event_call *call) |
9802d865 JB |
173 | { |
174 | struct trace_kprobe *tk = (struct trace_kprobe *)call->data; | |
9802d865 | 175 | |
45408c4f | 176 | return within_error_injection_list(trace_kprobe_address(tk)); |
9802d865 JB |
177 | } |
178 | ||
c31ffb3f NK |
179 | static int register_kprobe_event(struct trace_kprobe *tk); |
180 | static int unregister_kprobe_event(struct trace_kprobe *tk); | |
413d37d1 | 181 | |
50d78056 MH |
182 | static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs); |
183 | static int kretprobe_dispatcher(struct kretprobe_instance *ri, | |
184 | struct pt_regs *regs); | |
185 | ||
4a846b44 MH |
186 | /* |
187 | * Allocate new trace_probe and initialize it (including kprobes). | |
188 | */ | |
c31ffb3f | 189 | static struct trace_kprobe *alloc_trace_kprobe(const char *group, |
f52487e9 | 190 | const char *event, |
4a846b44 MH |
191 | void *addr, |
192 | const char *symbol, | |
193 | unsigned long offs, | |
696ced4f | 194 | int maxactive, |
3a6b7666 | 195 | int nargs, bool is_return) |
413d37d1 | 196 | { |
c31ffb3f | 197 | struct trace_kprobe *tk; |
6f3cf440 | 198 | int ret = -ENOMEM; |
413d37d1 | 199 | |
c31ffb3f NK |
200 | tk = kzalloc(SIZEOF_TRACE_KPROBE(nargs), GFP_KERNEL); |
201 | if (!tk) | |
6f3cf440 | 202 | return ERR_PTR(ret); |
413d37d1 | 203 | |
a7636d9e MKL |
204 | tk->nhit = alloc_percpu(unsigned long); |
205 | if (!tk->nhit) | |
206 | goto error; | |
207 | ||
413d37d1 | 208 | if (symbol) { |
c31ffb3f NK |
209 | tk->symbol = kstrdup(symbol, GFP_KERNEL); |
210 | if (!tk->symbol) | |
413d37d1 | 211 | goto error; |
c31ffb3f NK |
212 | tk->rp.kp.symbol_name = tk->symbol; |
213 | tk->rp.kp.offset = offs; | |
4a846b44 | 214 | } else |
c31ffb3f | 215 | tk->rp.kp.addr = addr; |
4a846b44 MH |
216 | |
217 | if (is_return) | |
c31ffb3f | 218 | tk->rp.handler = kretprobe_dispatcher; |
4a846b44 | 219 | else |
c31ffb3f | 220 | tk->rp.kp.pre_handler = kprobe_dispatcher; |
4a846b44 | 221 | |
696ced4f AC |
222 | tk->rp.maxactive = maxactive; |
223 | ||
5b7a9622 | 224 | if (!event || !group) { |
6f3cf440 | 225 | ret = -EINVAL; |
4263565d | 226 | goto error; |
6f3cf440 MH |
227 | } |
228 | ||
c31ffb3f NK |
229 | tk->tp.call.class = &tk->tp.class; |
230 | tk->tp.call.name = kstrdup(event, GFP_KERNEL); | |
231 | if (!tk->tp.call.name) | |
4263565d | 232 | goto error; |
413d37d1 | 233 | |
c31ffb3f NK |
234 | tk->tp.class.system = kstrdup(group, GFP_KERNEL); |
235 | if (!tk->tp.class.system) | |
f52487e9 MH |
236 | goto error; |
237 | ||
6212dd29 | 238 | dyn_event_init(&tk->devent, &trace_kprobe_ops); |
c31ffb3f NK |
239 | INIT_LIST_HEAD(&tk->tp.files); |
240 | return tk; | |
413d37d1 | 241 | error: |
c31ffb3f NK |
242 | kfree(tk->tp.call.name); |
243 | kfree(tk->symbol); | |
a7636d9e | 244 | free_percpu(tk->nhit); |
c31ffb3f | 245 | kfree(tk); |
6f3cf440 | 246 | return ERR_PTR(ret); |
413d37d1 MH |
247 | } |
248 | ||
c31ffb3f | 249 | static void free_trace_kprobe(struct trace_kprobe *tk) |
413d37d1 MH |
250 | { |
251 | int i; | |
252 | ||
6212dd29 MH |
253 | if (!tk) |
254 | return; | |
255 | ||
c31ffb3f NK |
256 | for (i = 0; i < tk->tp.nr_args; i++) |
257 | traceprobe_free_probe_arg(&tk->tp.args[i]); | |
413d37d1 | 258 | |
c31ffb3f NK |
259 | kfree(tk->tp.call.class->system); |
260 | kfree(tk->tp.call.name); | |
261 | kfree(tk->symbol); | |
a7636d9e | 262 | free_percpu(tk->nhit); |
c31ffb3f | 263 | kfree(tk); |
413d37d1 MH |
264 | } |
265 | ||
c31ffb3f NK |
266 | static struct trace_kprobe *find_trace_kprobe(const char *event, |
267 | const char *group) | |
413d37d1 | 268 | { |
6212dd29 | 269 | struct dyn_event *pos; |
c31ffb3f | 270 | struct trace_kprobe *tk; |
413d37d1 | 271 | |
6212dd29 | 272 | for_each_trace_kprobe(tk, pos) |
687fcc4a | 273 | if (strcmp(trace_event_name(&tk->tp.call), event) == 0 && |
c31ffb3f NK |
274 | strcmp(tk->tp.call.class->system, group) == 0) |
275 | return tk; | |
413d37d1 MH |
276 | return NULL; |
277 | } | |
278 | ||
87107a25 SRV |
279 | static inline int __enable_trace_kprobe(struct trace_kprobe *tk) |
280 | { | |
281 | int ret = 0; | |
282 | ||
283 | if (trace_probe_is_registered(&tk->tp) && !trace_kprobe_has_gone(tk)) { | |
284 | if (trace_kprobe_is_return(tk)) | |
285 | ret = enable_kretprobe(&tk->rp); | |
286 | else | |
287 | ret = enable_kprobe(&tk->rp.kp); | |
288 | } | |
289 | ||
290 | return ret; | |
291 | } | |
292 | ||
41a7dd42 MH |
293 | /* |
294 | * Enable trace_probe | |
295 | * if the file is NULL, enable "perf" handler, or enable "trace" handler. | |
296 | */ | |
297 | static int | |
7f1d2f82 | 298 | enable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file) |
1538f888 | 299 | { |
87107a25 | 300 | struct event_file_link *link; |
1538f888 MH |
301 | int ret = 0; |
302 | ||
41a7dd42 | 303 | if (file) { |
b04d52e3 ON |
304 | link = kmalloc(sizeof(*link), GFP_KERNEL); |
305 | if (!link) { | |
41a7dd42 | 306 | ret = -ENOMEM; |
3fe3d619 | 307 | goto out; |
41a7dd42 | 308 | } |
41a7dd42 | 309 | |
b04d52e3 | 310 | link->file = file; |
c31ffb3f | 311 | list_add_tail_rcu(&link->list, &tk->tp.files); |
41a7dd42 | 312 | |
c31ffb3f | 313 | tk->tp.flags |= TP_FLAG_TRACE; |
87107a25 SRV |
314 | ret = __enable_trace_kprobe(tk); |
315 | if (ret) { | |
316 | list_del_rcu(&link->list); | |
57ea2a34 AS |
317 | kfree(link); |
318 | tk->tp.flags &= ~TP_FLAG_TRACE; | |
57ea2a34 | 319 | } |
87107a25 SRV |
320 | |
321 | } else { | |
322 | tk->tp.flags |= TP_FLAG_PROFILE; | |
323 | ret = __enable_trace_kprobe(tk); | |
324 | if (ret) | |
325 | tk->tp.flags &= ~TP_FLAG_PROFILE; | |
57ea2a34 | 326 | } |
3fe3d619 | 327 | out: |
1538f888 MH |
328 | return ret; |
329 | } | |
330 | ||
41a7dd42 MH |
331 | /* |
332 | * Disable trace_probe | |
333 | * if the file is NULL, disable "perf" handler, or disable "trace" handler. | |
334 | */ | |
335 | static int | |
7f1d2f82 | 336 | disable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file) |
1538f888 | 337 | { |
a232e270 MH |
338 | struct event_file_link *link = NULL; |
339 | int wait = 0; | |
41a7dd42 MH |
340 | int ret = 0; |
341 | ||
41a7dd42 | 342 | if (file) { |
c31ffb3f | 343 | link = find_event_file_link(&tk->tp, file); |
b04d52e3 | 344 | if (!link) { |
41a7dd42 | 345 | ret = -EINVAL; |
3fe3d619 | 346 | goto out; |
41a7dd42 MH |
347 | } |
348 | ||
b04d52e3 | 349 | list_del_rcu(&link->list); |
a232e270 | 350 | wait = 1; |
c31ffb3f | 351 | if (!list_empty(&tk->tp.files)) |
b04d52e3 | 352 | goto out; |
41a7dd42 | 353 | |
c31ffb3f | 354 | tk->tp.flags &= ~TP_FLAG_TRACE; |
41a7dd42 | 355 | } else |
c31ffb3f | 356 | tk->tp.flags &= ~TP_FLAG_PROFILE; |
41a7dd42 | 357 | |
c31ffb3f NK |
358 | if (!trace_probe_is_enabled(&tk->tp) && trace_probe_is_registered(&tk->tp)) { |
359 | if (trace_kprobe_is_return(tk)) | |
360 | disable_kretprobe(&tk->rp); | |
1538f888 | 361 | else |
c31ffb3f | 362 | disable_kprobe(&tk->rp.kp); |
a232e270 | 363 | wait = 1; |
1538f888 | 364 | } |
e12f03d7 SL |
365 | |
366 | /* | |
367 | * if tk is not added to any list, it must be a local trace_kprobe | |
368 | * created with perf_event_open. We don't need to wait for these | |
369 | * trace_kprobes | |
370 | */ | |
6212dd29 | 371 | if (list_empty(&tk->devent.list)) |
e12f03d7 | 372 | wait = 0; |
3fe3d619 | 373 | out: |
a232e270 MH |
374 | if (wait) { |
375 | /* | |
376 | * Synchronize with kprobe_trace_func/kretprobe_trace_func | |
377 | * to ensure disabled (all running handlers are finished). | |
378 | * This is not only for kfree(), but also the caller, | |
379 | * trace_remove_event_call() supposes it for releasing | |
380 | * event_call related objects, which will be accessed in | |
381 | * the kprobe_trace_func/kretprobe_trace_func. | |
382 | */ | |
74401729 | 383 | synchronize_rcu(); |
a232e270 MH |
384 | kfree(link); /* Ignored if link == NULL */ |
385 | } | |
386 | ||
41a7dd42 | 387 | return ret; |
1538f888 MH |
388 | } |
389 | ||
45408c4f MH |
390 | #if defined(CONFIG_KPROBES_ON_FTRACE) && \ |
391 | !defined(CONFIG_KPROBE_EVENTS_ON_NOTRACE) | |
392 | static bool within_notrace_func(struct trace_kprobe *tk) | |
393 | { | |
394 | unsigned long offset, size, addr; | |
395 | ||
396 | addr = trace_kprobe_address(tk); | |
6bc6c77c MH |
397 | if (!addr || !kallsyms_lookup_size_offset(addr, &size, &offset)) |
398 | return false; | |
45408c4f | 399 | |
9161a864 MH |
400 | /* Get the entry address of the target function */ |
401 | addr -= offset; | |
402 | ||
403 | /* | |
404 | * Since ftrace_location_range() does inclusive range check, we need | |
405 | * to subtract 1 byte from the end address. | |
406 | */ | |
407 | return !ftrace_location_range(addr, addr + size - 1); | |
45408c4f MH |
408 | } |
409 | #else | |
410 | #define within_notrace_func(tk) (false) | |
411 | #endif | |
412 | ||
61424318 | 413 | /* Internal register function - just handle k*probes and flags */ |
c31ffb3f | 414 | static int __register_trace_kprobe(struct trace_kprobe *tk) |
413d37d1 | 415 | { |
a6682814 | 416 | int i, ret; |
61424318 | 417 | |
c31ffb3f | 418 | if (trace_probe_is_registered(&tk->tp)) |
61424318 MH |
419 | return -EINVAL; |
420 | ||
45408c4f MH |
421 | if (within_notrace_func(tk)) { |
422 | pr_warn("Could not probe notrace function %s\n", | |
423 | trace_kprobe_symbol(tk)); | |
424 | return -EINVAL; | |
425 | } | |
426 | ||
a6682814 MH |
427 | for (i = 0; i < tk->tp.nr_args; i++) { |
428 | ret = traceprobe_update_arg(&tk->tp.args[i]); | |
429 | if (ret) | |
430 | return ret; | |
431 | } | |
432 | ||
61424318 | 433 | /* Set/clear disabled flag according to tp->flag */ |
c31ffb3f NK |
434 | if (trace_probe_is_enabled(&tk->tp)) |
435 | tk->rp.kp.flags &= ~KPROBE_FLAG_DISABLED; | |
61424318 | 436 | else |
c31ffb3f | 437 | tk->rp.kp.flags |= KPROBE_FLAG_DISABLED; |
61424318 | 438 | |
c31ffb3f NK |
439 | if (trace_kprobe_is_return(tk)) |
440 | ret = register_kretprobe(&tk->rp); | |
413d37d1 | 441 | else |
c31ffb3f | 442 | ret = register_kprobe(&tk->rp.kp); |
61424318 | 443 | |
ab105a4f | 444 | if (ret == 0) |
c31ffb3f | 445 | tk->tp.flags |= TP_FLAG_REGISTERED; |
61424318 MH |
446 | return ret; |
447 | } | |
448 | ||
449 | /* Internal unregister function - just handle k*probes and flags */ | |
c31ffb3f | 450 | static void __unregister_trace_kprobe(struct trace_kprobe *tk) |
61424318 | 451 | { |
c31ffb3f NK |
452 | if (trace_probe_is_registered(&tk->tp)) { |
453 | if (trace_kprobe_is_return(tk)) | |
454 | unregister_kretprobe(&tk->rp); | |
61424318 | 455 | else |
c31ffb3f NK |
456 | unregister_kprobe(&tk->rp.kp); |
457 | tk->tp.flags &= ~TP_FLAG_REGISTERED; | |
61424318 | 458 | /* Cleanup kprobe for reuse */ |
c31ffb3f NK |
459 | if (tk->rp.kp.symbol_name) |
460 | tk->rp.kp.addr = NULL; | |
61424318 MH |
461 | } |
462 | } | |
463 | ||
6212dd29 | 464 | /* Unregister a trace_probe and probe_event */ |
c31ffb3f | 465 | static int unregister_trace_kprobe(struct trace_kprobe *tk) |
61424318 | 466 | { |
02ca1521 | 467 | /* Enabled event can not be unregistered */ |
c31ffb3f | 468 | if (trace_probe_is_enabled(&tk->tp)) |
02ca1521 MH |
469 | return -EBUSY; |
470 | ||
40c32592 | 471 | /* Will fail if probe is being used by ftrace or perf */ |
c31ffb3f | 472 | if (unregister_kprobe_event(tk)) |
40c32592 SRRH |
473 | return -EBUSY; |
474 | ||
c31ffb3f | 475 | __unregister_trace_kprobe(tk); |
6212dd29 | 476 | dyn_event_remove(&tk->devent); |
02ca1521 MH |
477 | |
478 | return 0; | |
413d37d1 MH |
479 | } |
480 | ||
481 | /* Register a trace_probe and probe_event */ | |
c31ffb3f | 482 | static int register_trace_kprobe(struct trace_kprobe *tk) |
413d37d1 | 483 | { |
c31ffb3f | 484 | struct trace_kprobe *old_tk; |
413d37d1 MH |
485 | int ret; |
486 | ||
6212dd29 | 487 | mutex_lock(&event_mutex); |
413d37d1 | 488 | |
61424318 | 489 | /* Delete old (same name) event if exist */ |
687fcc4a | 490 | old_tk = find_trace_kprobe(trace_event_name(&tk->tp.call), |
de7b2973 | 491 | tk->tp.call.class->system); |
c31ffb3f NK |
492 | if (old_tk) { |
493 | ret = unregister_trace_kprobe(old_tk); | |
02ca1521 MH |
494 | if (ret < 0) |
495 | goto end; | |
c31ffb3f | 496 | free_trace_kprobe(old_tk); |
2d5e067e | 497 | } |
61424318 MH |
498 | |
499 | /* Register new event */ | |
c31ffb3f | 500 | ret = register_kprobe_event(tk); |
2d5e067e | 501 | if (ret) { |
a395d6a7 | 502 | pr_warn("Failed to register probe event(%d)\n", ret); |
2d5e067e MH |
503 | goto end; |
504 | } | |
505 | ||
61424318 | 506 | /* Register k*probe */ |
c31ffb3f | 507 | ret = __register_trace_kprobe(tk); |
59158ec4 MH |
508 | if (ret == -ENOENT && !trace_kprobe_module_exist(tk)) { |
509 | pr_warn("This probe might be able to register after target module is loaded. Continue.\n"); | |
510 | ret = 0; | |
511 | } | |
512 | ||
61424318 | 513 | if (ret < 0) |
c31ffb3f | 514 | unregister_kprobe_event(tk); |
61424318 | 515 | else |
6212dd29 | 516 | dyn_event_add(&tk->devent); |
61424318 | 517 | |
413d37d1 | 518 | end: |
6212dd29 | 519 | mutex_unlock(&event_mutex); |
413d37d1 MH |
520 | return ret; |
521 | } | |
522 | ||
61424318 | 523 | /* Module notifier call back, checking event on the module */ |
c31ffb3f | 524 | static int trace_kprobe_module_callback(struct notifier_block *nb, |
61424318 MH |
525 | unsigned long val, void *data) |
526 | { | |
527 | struct module *mod = data; | |
6212dd29 | 528 | struct dyn_event *pos; |
c31ffb3f | 529 | struct trace_kprobe *tk; |
61424318 MH |
530 | int ret; |
531 | ||
532 | if (val != MODULE_STATE_COMING) | |
533 | return NOTIFY_DONE; | |
534 | ||
535 | /* Update probes on coming module */ | |
6212dd29 MH |
536 | mutex_lock(&event_mutex); |
537 | for_each_trace_kprobe(tk, pos) { | |
c31ffb3f | 538 | if (trace_kprobe_within_module(tk, mod)) { |
02ca1521 | 539 | /* Don't need to check busy - this should have gone. */ |
c31ffb3f NK |
540 | __unregister_trace_kprobe(tk); |
541 | ret = __register_trace_kprobe(tk); | |
61424318 | 542 | if (ret) |
a395d6a7 JP |
543 | pr_warn("Failed to re-register probe %s on %s: %d\n", |
544 | trace_event_name(&tk->tp.call), | |
545 | mod->name, ret); | |
61424318 MH |
546 | } |
547 | } | |
6212dd29 | 548 | mutex_unlock(&event_mutex); |
61424318 MH |
549 | |
550 | return NOTIFY_DONE; | |
551 | } | |
552 | ||
c31ffb3f NK |
553 | static struct notifier_block trace_kprobe_module_nb = { |
554 | .notifier_call = trace_kprobe_module_callback, | |
61424318 MH |
555 | .priority = 1 /* Invoked after kprobe module callback */ |
556 | }; | |
557 | ||
fca18a47 NR |
558 | /* Convert certain expected symbols into '_' when generating event names */ |
559 | static inline void sanitize_event_name(char *name) | |
560 | { | |
561 | while (*name++ != '\0') | |
562 | if (*name == ':' || *name == '.') | |
563 | *name = '_'; | |
564 | } | |
565 | ||
6212dd29 | 566 | static int trace_kprobe_create(int argc, const char *argv[]) |
413d37d1 MH |
567 | { |
568 | /* | |
569 | * Argument syntax: | |
696ced4f AC |
570 | * - Add kprobe: |
571 | * p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS] | |
572 | * - Add kretprobe: | |
573 | * r[MAXACTIVE][:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS] | |
413d37d1 | 574 | * Fetch args: |
2e06ff63 MH |
575 | * $retval : fetch return value |
576 | * $stack : fetch stack address | |
577 | * $stackN : fetch Nth of stack (N:0-) | |
35abb67d | 578 | * $comm : fetch current task comm |
413d37d1 MH |
579 | * @ADDR : fetch memory at ADDR (ADDR should be in kernel) |
580 | * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol) | |
581 | * %REG : fetch register REG | |
93ccae7a | 582 | * Dereferencing memory fetch: |
413d37d1 | 583 | * +|-offs(ARG) : fetch memory at ARG +|- offs address. |
eca0d916 MH |
584 | * Alias name of args: |
585 | * NAME=FETCHARG : set NAME as alias of FETCHARG. | |
93ccae7a MH |
586 | * Type of args: |
587 | * FETCHARG:TYPE : use TYPE instead of unsigned long. | |
413d37d1 | 588 | */ |
ab105a4f | 589 | struct trace_kprobe *tk = NULL; |
6212dd29 MH |
590 | int i, len, ret = 0; |
591 | bool is_return = false; | |
592 | char *symbol = NULL, *tmp = NULL; | |
593 | const char *event = NULL, *group = KPROBE_EVENT_SYSTEM; | |
696ced4f | 594 | int maxactive = 0; |
c5d343b6 | 595 | long offset = 0; |
413d37d1 | 596 | void *addr = NULL; |
4a846b44 | 597 | char buf[MAX_EVENT_NAME_LEN]; |
a1303af5 | 598 | unsigned int flags = TPARG_FL_KERNEL; |
413d37d1 | 599 | |
8b05a3a7 AR |
600 | switch (argv[0][0]) { |
601 | case 'r': | |
3a6b7666 | 602 | is_return = true; |
a1303af5 | 603 | flags |= TPARG_FL_RETURN; |
8b05a3a7 AR |
604 | break; |
605 | case 'p': | |
606 | break; | |
607 | default: | |
608 | return -ECANCELED; | |
609 | } | |
610 | if (argc < 2) | |
6212dd29 | 611 | return -ECANCELED; |
413d37d1 | 612 | |
ab105a4f MH |
613 | trace_probe_log_init("trace_kprobe", argc, argv); |
614 | ||
696ced4f | 615 | event = strchr(&argv[0][1], ':'); |
6212dd29 | 616 | if (event) |
696ced4f | 617 | event++; |
6212dd29 | 618 | |
287c038c MH |
619 | if (isdigit(argv[0][1])) { |
620 | if (!is_return) { | |
ab105a4f MH |
621 | trace_probe_log_err(1, MAXACT_NO_KPROBE); |
622 | goto parse_error; | |
287c038c | 623 | } |
6212dd29 MH |
624 | if (event) |
625 | len = event - &argv[0][1] - 1; | |
626 | else | |
627 | len = strlen(&argv[0][1]); | |
ab105a4f MH |
628 | if (len > MAX_EVENT_NAME_LEN - 1) { |
629 | trace_probe_log_err(1, BAD_MAXACT); | |
630 | goto parse_error; | |
631 | } | |
6212dd29 MH |
632 | memcpy(buf, &argv[0][1], len); |
633 | buf[len] = '\0'; | |
634 | ret = kstrtouint(buf, 0, &maxactive); | |
287c038c | 635 | if (ret || !maxactive) { |
ab105a4f MH |
636 | trace_probe_log_err(1, BAD_MAXACT); |
637 | goto parse_error; | |
696ced4f AC |
638 | } |
639 | /* kretprobes instances are iterated over via a list. The | |
640 | * maximum should stay reasonable. | |
641 | */ | |
642 | if (maxactive > KRETPROBE_MAXACTIVE_MAX) { | |
ab105a4f MH |
643 | trace_probe_log_err(1, MAXACT_TOO_BIG); |
644 | goto parse_error; | |
696ced4f AC |
645 | } |
646 | } | |
647 | ||
9e52b325 SD |
648 | /* try to parse an address. if that fails, try to read the |
649 | * input as a symbol. */ | |
650 | if (kstrtoul(argv[1], 0, (unsigned long *)&addr)) { | |
ab105a4f | 651 | trace_probe_log_set_index(1); |
6212dd29 | 652 | /* Check whether uprobe event specified */ |
ab105a4f MH |
653 | if (strchr(argv[1], '/') && strchr(argv[1], ':')) { |
654 | ret = -ECANCELED; | |
655 | goto error; | |
656 | } | |
413d37d1 | 657 | /* a symbol specified */ |
6212dd29 MH |
658 | symbol = kstrdup(argv[1], GFP_KERNEL); |
659 | if (!symbol) | |
660 | return -ENOMEM; | |
413d37d1 | 661 | /* TODO: support .init module functions */ |
8ab83f56 | 662 | ret = traceprobe_split_symbol_offset(symbol, &offset); |
c5d343b6 | 663 | if (ret || offset < 0 || offset > UINT_MAX) { |
ab105a4f MH |
664 | trace_probe_log_err(0, BAD_PROBE_ADDR); |
665 | goto parse_error; | |
e63cc239 | 666 | } |
a1303af5 MH |
667 | if (kprobe_on_func_entry(NULL, symbol, offset)) |
668 | flags |= TPARG_FL_FENTRY; | |
669 | if (offset && is_return && !(flags & TPARG_FL_FENTRY)) { | |
ab105a4f MH |
670 | trace_probe_log_err(0, BAD_RETPROBE); |
671 | goto parse_error; | |
e63cc239 | 672 | } |
413d37d1 MH |
673 | } |
674 | ||
ab105a4f | 675 | trace_probe_log_set_index(0); |
6212dd29 | 676 | if (event) { |
ab105a4f MH |
677 | ret = traceprobe_parse_event_name(&event, &group, buf, |
678 | event - argv[0]); | |
6212dd29 | 679 | if (ret) |
ab105a4f | 680 | goto parse_error; |
6212dd29 | 681 | } else { |
4263565d | 682 | /* Make a new event name */ |
4263565d | 683 | if (symbol) |
6f3cf440 | 684 | snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld", |
4263565d MH |
685 | is_return ? 'r' : 'p', symbol, offset); |
686 | else | |
6f3cf440 | 687 | snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p", |
4263565d | 688 | is_return ? 'r' : 'p', addr); |
fca18a47 | 689 | sanitize_event_name(buf); |
4a846b44 MH |
690 | event = buf; |
691 | } | |
6212dd29 MH |
692 | |
693 | /* setup a probe */ | |
696ced4f | 694 | tk = alloc_trace_kprobe(group, event, addr, symbol, offset, maxactive, |
ab105a4f | 695 | argc - 2, is_return); |
c31ffb3f | 696 | if (IS_ERR(tk)) { |
6212dd29 | 697 | ret = PTR_ERR(tk); |
ab105a4f | 698 | /* This must return -ENOMEM, else there is a bug */ |
a039480e | 699 | WARN_ON_ONCE(ret != -ENOMEM); |
ab105a4f | 700 | goto out; /* We know tk is not allocated */ |
e63cc239 | 701 | } |
ab105a4f | 702 | argc -= 2; argv += 2; |
413d37d1 | 703 | |
413d37d1 | 704 | /* parse arguments */ |
a82378d8 | 705 | for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { |
6212dd29 MH |
706 | tmp = kstrdup(argv[i], GFP_KERNEL); |
707 | if (!tmp) { | |
ba8665d7 | 708 | ret = -ENOMEM; |
413d37d1 MH |
709 | goto error; |
710 | } | |
da34634f | 711 | |
ab105a4f | 712 | trace_probe_log_set_index(i + 2); |
6212dd29 MH |
713 | ret = traceprobe_parse_probe_arg(&tk->tp, i, tmp, flags); |
714 | kfree(tmp); | |
d00bbea9 | 715 | if (ret) |
ab105a4f | 716 | goto error; /* This can be -ENOMEM */ |
413d37d1 | 717 | } |
413d37d1 | 718 | |
c31ffb3f | 719 | ret = register_trace_kprobe(tk); |
ab105a4f MH |
720 | if (ret) { |
721 | trace_probe_log_set_index(1); | |
722 | if (ret == -EILSEQ) | |
723 | trace_probe_log_err(0, BAD_INSN_BNDRY); | |
724 | else if (ret == -ENOENT) | |
725 | trace_probe_log_err(0, BAD_PROBE_ADDR); | |
726 | else if (ret != -ENOMEM) | |
727 | trace_probe_log_err(0, FAIL_REG_PROBE); | |
413d37d1 | 728 | goto error; |
ab105a4f MH |
729 | } |
730 | ||
6212dd29 | 731 | out: |
ab105a4f | 732 | trace_probe_log_clear(); |
6212dd29 MH |
733 | kfree(symbol); |
734 | return ret; | |
413d37d1 | 735 | |
ab105a4f MH |
736 | parse_error: |
737 | ret = -EINVAL; | |
413d37d1 | 738 | error: |
c31ffb3f | 739 | free_trace_kprobe(tk); |
6212dd29 | 740 | goto out; |
413d37d1 MH |
741 | } |
742 | ||
6212dd29 | 743 | static int create_or_delete_trace_kprobe(int argc, char **argv) |
413d37d1 | 744 | { |
6212dd29 | 745 | int ret; |
02ca1521 | 746 | |
6212dd29 MH |
747 | if (argv[0][0] == '-') |
748 | return dyn_event_release(argc, argv, &trace_kprobe_ops); | |
413d37d1 | 749 | |
6212dd29 MH |
750 | ret = trace_kprobe_create(argc, (const char **)argv); |
751 | return ret == -ECANCELED ? -EINVAL : ret; | |
413d37d1 MH |
752 | } |
753 | ||
6212dd29 | 754 | static int trace_kprobe_release(struct dyn_event *ev) |
413d37d1 | 755 | { |
6212dd29 MH |
756 | struct trace_kprobe *tk = to_trace_kprobe(ev); |
757 | int ret = unregister_trace_kprobe(tk); | |
413d37d1 | 758 | |
6212dd29 MH |
759 | if (!ret) |
760 | free_trace_kprobe(tk); | |
761 | return ret; | |
413d37d1 MH |
762 | } |
763 | ||
6212dd29 | 764 | static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev) |
413d37d1 | 765 | { |
6212dd29 | 766 | struct trace_kprobe *tk = to_trace_kprobe(ev); |
93ccae7a | 767 | int i; |
413d37d1 | 768 | |
fa6f0cc7 | 769 | seq_putc(m, trace_kprobe_is_return(tk) ? 'r' : 'p'); |
de7b2973 | 770 | seq_printf(m, ":%s/%s", tk->tp.call.class->system, |
687fcc4a | 771 | trace_event_name(&tk->tp.call)); |
413d37d1 | 772 | |
c31ffb3f NK |
773 | if (!tk->symbol) |
774 | seq_printf(m, " 0x%p", tk->rp.kp.addr); | |
775 | else if (tk->rp.kp.offset) | |
776 | seq_printf(m, " %s+%u", trace_kprobe_symbol(tk), | |
777 | tk->rp.kp.offset); | |
413d37d1 | 778 | else |
c31ffb3f | 779 | seq_printf(m, " %s", trace_kprobe_symbol(tk)); |
413d37d1 | 780 | |
c31ffb3f NK |
781 | for (i = 0; i < tk->tp.nr_args; i++) |
782 | seq_printf(m, " %s=%s", tk->tp.args[i].name, tk->tp.args[i].comm); | |
fa6f0cc7 | 783 | seq_putc(m, '\n'); |
93ccae7a | 784 | |
413d37d1 MH |
785 | return 0; |
786 | } | |
787 | ||
6212dd29 MH |
788 | static int probes_seq_show(struct seq_file *m, void *v) |
789 | { | |
790 | struct dyn_event *ev = v; | |
791 | ||
792 | if (!is_trace_kprobe(ev)) | |
793 | return 0; | |
794 | ||
795 | return trace_kprobe_show(m, ev); | |
796 | } | |
797 | ||
413d37d1 | 798 | static const struct seq_operations probes_seq_op = { |
6212dd29 MH |
799 | .start = dyn_event_seq_start, |
800 | .next = dyn_event_seq_next, | |
801 | .stop = dyn_event_seq_stop, | |
413d37d1 MH |
802 | .show = probes_seq_show |
803 | }; | |
804 | ||
805 | static int probes_open(struct inode *inode, struct file *file) | |
806 | { | |
02ca1521 MH |
807 | int ret; |
808 | ||
809 | if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { | |
6212dd29 | 810 | ret = dyn_events_release_all(&trace_kprobe_ops); |
02ca1521 MH |
811 | if (ret < 0) |
812 | return ret; | |
813 | } | |
413d37d1 MH |
814 | |
815 | return seq_open(file, &probes_seq_op); | |
816 | } | |
817 | ||
413d37d1 MH |
818 | static ssize_t probes_write(struct file *file, const char __user *buffer, |
819 | size_t count, loff_t *ppos) | |
820 | { | |
7e465baa | 821 | return trace_parse_run_command(file, buffer, count, ppos, |
6212dd29 | 822 | create_or_delete_trace_kprobe); |
413d37d1 MH |
823 | } |
824 | ||
825 | static const struct file_operations kprobe_events_ops = { | |
826 | .owner = THIS_MODULE, | |
827 | .open = probes_open, | |
828 | .read = seq_read, | |
829 | .llseek = seq_lseek, | |
830 | .release = seq_release, | |
831 | .write = probes_write, | |
832 | }; | |
833 | ||
cd7e7bd5 MH |
834 | /* Probes profiling interfaces */ |
835 | static int probes_profile_seq_show(struct seq_file *m, void *v) | |
836 | { | |
6212dd29 MH |
837 | struct dyn_event *ev = v; |
838 | struct trace_kprobe *tk; | |
cd7e7bd5 | 839 | |
6212dd29 MH |
840 | if (!is_trace_kprobe(ev)) |
841 | return 0; | |
cd7e7bd5 | 842 | |
6212dd29 | 843 | tk = to_trace_kprobe(ev); |
de7b2973 | 844 | seq_printf(m, " %-44s %15lu %15lu\n", |
f18f97ac MN |
845 | trace_event_name(&tk->tp.call), |
846 | trace_kprobe_nhit(tk), | |
c31ffb3f | 847 | tk->rp.kp.nmissed); |
cd7e7bd5 MH |
848 | |
849 | return 0; | |
850 | } | |
851 | ||
852 | static const struct seq_operations profile_seq_op = { | |
6212dd29 MH |
853 | .start = dyn_event_seq_start, |
854 | .next = dyn_event_seq_next, | |
855 | .stop = dyn_event_seq_stop, | |
cd7e7bd5 MH |
856 | .show = probes_profile_seq_show |
857 | }; | |
858 | ||
859 | static int profile_open(struct inode *inode, struct file *file) | |
860 | { | |
861 | return seq_open(file, &profile_seq_op); | |
862 | } | |
863 | ||
864 | static const struct file_operations kprobe_profile_ops = { | |
865 | .owner = THIS_MODULE, | |
866 | .open = profile_open, | |
867 | .read = seq_read, | |
868 | .llseek = seq_lseek, | |
869 | .release = seq_release, | |
870 | }; | |
871 | ||
53305928 MH |
872 | /* Kprobe specific fetch functions */ |
873 | ||
874 | /* Return the length of string -- including null terminal byte */ | |
9178412d MH |
875 | static nokprobe_inline int |
876 | fetch_store_strlen(unsigned long addr) | |
53305928 | 877 | { |
53305928 MH |
878 | int ret, len = 0; |
879 | u8 c; | |
880 | ||
53305928 | 881 | do { |
49ef5f45 | 882 | ret = probe_kernel_read(&c, (u8 *)addr + len, 1); |
53305928 MH |
883 | len++; |
884 | } while (c && ret == 0 && len < MAX_STRING_SIZE); | |
885 | ||
9178412d | 886 | return (ret < 0) ? ret : len; |
53305928 MH |
887 | } |
888 | ||
889 | /* | |
890 | * Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max | |
891 | * length and relative data location. | |
892 | */ | |
9178412d MH |
893 | static nokprobe_inline int |
894 | fetch_store_string(unsigned long addr, void *dest, void *base) | |
53305928 | 895 | { |
9178412d MH |
896 | int maxlen = get_loc_len(*(u32 *)dest); |
897 | u8 *dst = get_loc_data(dest, base); | |
53305928 MH |
898 | long ret; |
899 | ||
9178412d MH |
900 | if (unlikely(!maxlen)) |
901 | return -ENOMEM; | |
53305928 MH |
902 | /* |
903 | * Try to get string again, since the string can be changed while | |
904 | * probing. | |
905 | */ | |
906 | ret = strncpy_from_unsafe(dst, (void *)addr, maxlen); | |
907 | ||
9178412d MH |
908 | if (ret >= 0) |
909 | *(u32 *)dest = make_data_loc(ret, (void *)dst - base); | |
910 | return ret; | |
53305928 MH |
911 | } |
912 | ||
9b960a38 MH |
913 | static nokprobe_inline int |
914 | probe_mem_read(void *dest, void *src, size_t size) | |
915 | { | |
916 | return probe_kernel_read(dest, src, size); | |
917 | } | |
918 | ||
53305928 MH |
919 | /* Note that we don't verify it, since the code does not come from user space */ |
920 | static int | |
921 | process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest, | |
9178412d | 922 | void *base) |
53305928 MH |
923 | { |
924 | unsigned long val; | |
53305928 | 925 | |
a6682814 | 926 | retry: |
53305928 MH |
927 | /* 1st stage: get value from context */ |
928 | switch (code->op) { | |
929 | case FETCH_OP_REG: | |
930 | val = regs_get_register(regs, code->param); | |
931 | break; | |
932 | case FETCH_OP_STACK: | |
933 | val = regs_get_kernel_stack_nth(regs, code->param); | |
934 | break; | |
935 | case FETCH_OP_STACKP: | |
936 | val = kernel_stack_pointer(regs); | |
937 | break; | |
938 | case FETCH_OP_RETVAL: | |
939 | val = regs_return_value(regs); | |
940 | break; | |
941 | case FETCH_OP_IMM: | |
942 | val = code->immediate; | |
943 | break; | |
944 | case FETCH_OP_COMM: | |
945 | val = (unsigned long)current->comm; | |
946 | break; | |
a1303af5 MH |
947 | #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API |
948 | case FETCH_OP_ARG: | |
949 | val = regs_get_kernel_argument(regs, code->param); | |
950 | break; | |
951 | #endif | |
a6682814 MH |
952 | case FETCH_NOP_SYMBOL: /* Ignore a place holder */ |
953 | code++; | |
954 | goto retry; | |
53305928 MH |
955 | default: |
956 | return -EILSEQ; | |
957 | } | |
958 | code++; | |
959 | ||
9b960a38 | 960 | return process_fetch_insn_bottom(code, val, dest, base); |
53305928 MH |
961 | } |
962 | NOKPROBE_SYMBOL(process_fetch_insn) | |
963 | ||
413d37d1 | 964 | /* Kprobe handler */ |
3da0f180 | 965 | static nokprobe_inline void |
c31ffb3f | 966 | __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs, |
7f1d2f82 | 967 | struct trace_event_file *trace_file) |
413d37d1 | 968 | { |
93ccae7a | 969 | struct kprobe_trace_entry_head *entry; |
413d37d1 | 970 | struct ring_buffer_event *event; |
8f8ffe24 | 971 | struct ring_buffer *buffer; |
e09c8614 | 972 | int size, dsize, pc; |
413d37d1 | 973 | unsigned long irq_flags; |
2425bcb9 | 974 | struct trace_event_call *call = &tk->tp.call; |
413d37d1 | 975 | |
7f1d2f82 | 976 | WARN_ON(call != trace_file->event_call); |
41a7dd42 | 977 | |
09a5059a | 978 | if (trace_trigger_soft_disabled(trace_file)) |
13a1e4ae | 979 | return; |
b8820084 | 980 | |
413d37d1 MH |
981 | local_save_flags(irq_flags); |
982 | pc = preempt_count(); | |
983 | ||
c31ffb3f NK |
984 | dsize = __get_data_size(&tk->tp, regs); |
985 | size = sizeof(*entry) + tk->tp.size + dsize; | |
413d37d1 | 986 | |
7f1d2f82 | 987 | event = trace_event_buffer_lock_reserve(&buffer, trace_file, |
41a7dd42 MH |
988 | call->event.type, |
989 | size, irq_flags, pc); | |
413d37d1 | 990 | if (!event) |
1e12a4a7 | 991 | return; |
413d37d1 MH |
992 | |
993 | entry = ring_buffer_event_data(event); | |
c31ffb3f | 994 | entry->ip = (unsigned long)tk->rp.kp.addr; |
9178412d | 995 | store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize); |
413d37d1 | 996 | |
7f1d2f82 | 997 | event_trigger_unlock_commit_regs(trace_file, buffer, event, |
13a1e4ae | 998 | entry, irq_flags, pc, regs); |
413d37d1 MH |
999 | } |
1000 | ||
3da0f180 | 1001 | static void |
c31ffb3f | 1002 | kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs) |
41a7dd42 | 1003 | { |
b04d52e3 | 1004 | struct event_file_link *link; |
41a7dd42 | 1005 | |
c31ffb3f NK |
1006 | list_for_each_entry_rcu(link, &tk->tp.files, list) |
1007 | __kprobe_trace_func(tk, regs, link->file); | |
41a7dd42 | 1008 | } |
3da0f180 | 1009 | NOKPROBE_SYMBOL(kprobe_trace_func); |
41a7dd42 | 1010 | |
413d37d1 | 1011 | /* Kretprobe handler */ |
3da0f180 | 1012 | static nokprobe_inline void |
c31ffb3f | 1013 | __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, |
41a7dd42 | 1014 | struct pt_regs *regs, |
7f1d2f82 | 1015 | struct trace_event_file *trace_file) |
413d37d1 | 1016 | { |
93ccae7a | 1017 | struct kretprobe_trace_entry_head *entry; |
413d37d1 | 1018 | struct ring_buffer_event *event; |
8f8ffe24 | 1019 | struct ring_buffer *buffer; |
e09c8614 | 1020 | int size, pc, dsize; |
413d37d1 | 1021 | unsigned long irq_flags; |
2425bcb9 | 1022 | struct trace_event_call *call = &tk->tp.call; |
413d37d1 | 1023 | |
7f1d2f82 | 1024 | WARN_ON(call != trace_file->event_call); |
41a7dd42 | 1025 | |
09a5059a | 1026 | if (trace_trigger_soft_disabled(trace_file)) |
13a1e4ae | 1027 | return; |
b8820084 | 1028 | |
413d37d1 MH |
1029 | local_save_flags(irq_flags); |
1030 | pc = preempt_count(); | |
1031 | ||
c31ffb3f NK |
1032 | dsize = __get_data_size(&tk->tp, regs); |
1033 | size = sizeof(*entry) + tk->tp.size + dsize; | |
413d37d1 | 1034 | |
7f1d2f82 | 1035 | event = trace_event_buffer_lock_reserve(&buffer, trace_file, |
41a7dd42 MH |
1036 | call->event.type, |
1037 | size, irq_flags, pc); | |
413d37d1 | 1038 | if (!event) |
1e12a4a7 | 1039 | return; |
413d37d1 MH |
1040 | |
1041 | entry = ring_buffer_event_data(event); | |
c31ffb3f | 1042 | entry->func = (unsigned long)tk->rp.kp.addr; |
413d37d1 | 1043 | entry->ret_ip = (unsigned long)ri->ret_addr; |
9178412d | 1044 | store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize); |
413d37d1 | 1045 | |
7f1d2f82 | 1046 | event_trigger_unlock_commit_regs(trace_file, buffer, event, |
13a1e4ae | 1047 | entry, irq_flags, pc, regs); |
413d37d1 MH |
1048 | } |
1049 | ||
3da0f180 | 1050 | static void |
c31ffb3f | 1051 | kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, |
41a7dd42 MH |
1052 | struct pt_regs *regs) |
1053 | { | |
b04d52e3 | 1054 | struct event_file_link *link; |
41a7dd42 | 1055 | |
c31ffb3f NK |
1056 | list_for_each_entry_rcu(link, &tk->tp.files, list) |
1057 | __kretprobe_trace_func(tk, ri, regs, link->file); | |
41a7dd42 | 1058 | } |
3da0f180 | 1059 | NOKPROBE_SYMBOL(kretprobe_trace_func); |
41a7dd42 | 1060 | |
413d37d1 | 1061 | /* Event entry printers */ |
b62fdd97 | 1062 | static enum print_line_t |
a9a57763 SR |
1063 | print_kprobe_event(struct trace_iterator *iter, int flags, |
1064 | struct trace_event *event) | |
413d37d1 | 1065 | { |
93ccae7a | 1066 | struct kprobe_trace_entry_head *field; |
413d37d1 | 1067 | struct trace_seq *s = &iter->seq; |
eca0d916 | 1068 | struct trace_probe *tp; |
413d37d1 | 1069 | |
93ccae7a | 1070 | field = (struct kprobe_trace_entry_head *)iter->ent; |
80decc70 | 1071 | tp = container_of(event, struct trace_probe, call.event); |
413d37d1 | 1072 | |
687fcc4a | 1073 | trace_seq_printf(s, "%s: (", trace_event_name(&tp->call)); |
6e9f23d1 | 1074 | |
413d37d1 | 1075 | if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET)) |
85224da0 | 1076 | goto out; |
413d37d1 | 1077 | |
85224da0 | 1078 | trace_seq_putc(s, ')'); |
413d37d1 | 1079 | |
56de7630 MH |
1080 | if (print_probe_args(s, tp->args, tp->nr_args, |
1081 | (u8 *)&field[1], field) < 0) | |
1082 | goto out; | |
413d37d1 | 1083 | |
85224da0 SRRH |
1084 | trace_seq_putc(s, '\n'); |
1085 | out: | |
1086 | return trace_handle_return(s); | |
413d37d1 MH |
1087 | } |
1088 | ||
b62fdd97 | 1089 | static enum print_line_t |
a9a57763 SR |
1090 | print_kretprobe_event(struct trace_iterator *iter, int flags, |
1091 | struct trace_event *event) | |
413d37d1 | 1092 | { |
93ccae7a | 1093 | struct kretprobe_trace_entry_head *field; |
413d37d1 | 1094 | struct trace_seq *s = &iter->seq; |
eca0d916 | 1095 | struct trace_probe *tp; |
413d37d1 | 1096 | |
93ccae7a | 1097 | field = (struct kretprobe_trace_entry_head *)iter->ent; |
80decc70 | 1098 | tp = container_of(event, struct trace_probe, call.event); |
413d37d1 | 1099 | |
687fcc4a | 1100 | trace_seq_printf(s, "%s: (", trace_event_name(&tp->call)); |
6e9f23d1 | 1101 | |
413d37d1 | 1102 | if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET)) |
85224da0 | 1103 | goto out; |
413d37d1 | 1104 | |
85224da0 | 1105 | trace_seq_puts(s, " <- "); |
413d37d1 MH |
1106 | |
1107 | if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET)) | |
85224da0 | 1108 | goto out; |
413d37d1 | 1109 | |
85224da0 | 1110 | trace_seq_putc(s, ')'); |
413d37d1 | 1111 | |
56de7630 MH |
1112 | if (print_probe_args(s, tp->args, tp->nr_args, |
1113 | (u8 *)&field[1], field) < 0) | |
1114 | goto out; | |
413d37d1 | 1115 | |
85224da0 | 1116 | trace_seq_putc(s, '\n'); |
413d37d1 | 1117 | |
85224da0 SRRH |
1118 | out: |
1119 | return trace_handle_return(s); | |
413d37d1 MH |
1120 | } |
1121 | ||
413d37d1 | 1122 | |
2425bcb9 | 1123 | static int kprobe_event_define_fields(struct trace_event_call *event_call) |
413d37d1 | 1124 | { |
eeb07b06 | 1125 | int ret; |
93ccae7a | 1126 | struct kprobe_trace_entry_head field; |
c31ffb3f | 1127 | struct trace_kprobe *tk = (struct trace_kprobe *)event_call->data; |
413d37d1 | 1128 | |
a703d946 | 1129 | DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0); |
c31ffb3f | 1130 | |
eeb07b06 | 1131 | return traceprobe_define_arg_fields(event_call, sizeof(field), &tk->tp); |
413d37d1 MH |
1132 | } |
1133 | ||
2425bcb9 | 1134 | static int kretprobe_event_define_fields(struct trace_event_call *event_call) |
413d37d1 | 1135 | { |
eeb07b06 | 1136 | int ret; |
93ccae7a | 1137 | struct kretprobe_trace_entry_head field; |
c31ffb3f | 1138 | struct trace_kprobe *tk = (struct trace_kprobe *)event_call->data; |
413d37d1 | 1139 | |
a703d946 MH |
1140 | DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0); |
1141 | DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0); | |
c31ffb3f | 1142 | |
eeb07b06 | 1143 | return traceprobe_define_arg_fields(event_call, sizeof(field), &tk->tp); |
413d37d1 MH |
1144 | } |
1145 | ||
07b139c8 | 1146 | #ifdef CONFIG_PERF_EVENTS |
e08d1c65 MH |
1147 | |
1148 | /* Kprobe profile handler */ | |
9802d865 | 1149 | static int |
c31ffb3f | 1150 | kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs) |
e08d1c65 | 1151 | { |
2425bcb9 | 1152 | struct trace_event_call *call = &tk->tp.call; |
93ccae7a | 1153 | struct kprobe_trace_entry_head *entry; |
1c024eca | 1154 | struct hlist_head *head; |
e09c8614 | 1155 | int size, __size, dsize; |
4ed7c92d | 1156 | int rctx; |
e08d1c65 | 1157 | |
9802d865 | 1158 | if (bpf_prog_array_valid(call)) { |
66665ad2 | 1159 | unsigned long orig_ip = instruction_pointer(regs); |
9802d865 JB |
1160 | int ret; |
1161 | ||
1162 | ret = trace_call_bpf(call, regs); | |
1163 | ||
1164 | /* | |
1165 | * We need to check and see if we modified the pc of the | |
cce188bd MH |
1166 | * pt_regs, and if so return 1 so that we don't do the |
1167 | * single stepping. | |
9802d865 | 1168 | */ |
cce188bd | 1169 | if (orig_ip != instruction_pointer(regs)) |
9802d865 | 1170 | return 1; |
9802d865 JB |
1171 | if (!ret) |
1172 | return 0; | |
1173 | } | |
2541517c | 1174 | |
288e984e ON |
1175 | head = this_cpu_ptr(call->perf_events); |
1176 | if (hlist_empty(head)) | |
9802d865 | 1177 | return 0; |
288e984e | 1178 | |
c31ffb3f NK |
1179 | dsize = __get_data_size(&tk->tp, regs); |
1180 | __size = sizeof(*entry) + tk->tp.size + dsize; | |
74ebb63e MH |
1181 | size = ALIGN(__size + sizeof(u32), sizeof(u64)); |
1182 | size -= sizeof(u32); | |
ce71b9df | 1183 | |
1e1dcd93 | 1184 | entry = perf_trace_buf_alloc(size, NULL, &rctx); |
430ad5a6 | 1185 | if (!entry) |
9802d865 | 1186 | return 0; |
a1a138d0 | 1187 | |
c31ffb3f | 1188 | entry->ip = (unsigned long)tk->rp.kp.addr; |
e09c8614 | 1189 | memset(&entry[1], 0, dsize); |
9178412d | 1190 | store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize); |
1e1dcd93 | 1191 | perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, |
8fd0fbbe | 1192 | head, NULL); |
9802d865 | 1193 | return 0; |
e08d1c65 | 1194 | } |
3da0f180 | 1195 | NOKPROBE_SYMBOL(kprobe_perf_func); |
e08d1c65 MH |
1196 | |
1197 | /* Kretprobe profile handler */ | |
3da0f180 | 1198 | static void |
c31ffb3f | 1199 | kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, |
2b106aab | 1200 | struct pt_regs *regs) |
e08d1c65 | 1201 | { |
2425bcb9 | 1202 | struct trace_event_call *call = &tk->tp.call; |
93ccae7a | 1203 | struct kretprobe_trace_entry_head *entry; |
1c024eca | 1204 | struct hlist_head *head; |
e09c8614 | 1205 | int size, __size, dsize; |
4ed7c92d | 1206 | int rctx; |
e08d1c65 | 1207 | |
e87c6bc3 | 1208 | if (bpf_prog_array_valid(call) && !trace_call_bpf(call, regs)) |
2541517c AS |
1209 | return; |
1210 | ||
288e984e ON |
1211 | head = this_cpu_ptr(call->perf_events); |
1212 | if (hlist_empty(head)) | |
1213 | return; | |
1214 | ||
c31ffb3f NK |
1215 | dsize = __get_data_size(&tk->tp, regs); |
1216 | __size = sizeof(*entry) + tk->tp.size + dsize; | |
74ebb63e MH |
1217 | size = ALIGN(__size + sizeof(u32), sizeof(u64)); |
1218 | size -= sizeof(u32); | |
444a2a3b | 1219 | |
1e1dcd93 | 1220 | entry = perf_trace_buf_alloc(size, NULL, &rctx); |
430ad5a6 | 1221 | if (!entry) |
1e12a4a7 | 1222 | return; |
e08d1c65 | 1223 | |
c31ffb3f | 1224 | entry->func = (unsigned long)tk->rp.kp.addr; |
a1a138d0 | 1225 | entry->ret_ip = (unsigned long)ri->ret_addr; |
9178412d | 1226 | store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize); |
1e1dcd93 | 1227 | perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, |
8fd0fbbe | 1228 | head, NULL); |
e08d1c65 | 1229 | } |
3da0f180 | 1230 | NOKPROBE_SYMBOL(kretprobe_perf_func); |
41bdc4b4 YS |
1231 | |
1232 | int bpf_get_kprobe_info(const struct perf_event *event, u32 *fd_type, | |
1233 | const char **symbol, u64 *probe_offset, | |
1234 | u64 *probe_addr, bool perf_type_tracepoint) | |
1235 | { | |
1236 | const char *pevent = trace_event_name(event->tp_event); | |
1237 | const char *group = event->tp_event->class->system; | |
1238 | struct trace_kprobe *tk; | |
1239 | ||
1240 | if (perf_type_tracepoint) | |
1241 | tk = find_trace_kprobe(pevent, group); | |
1242 | else | |
1243 | tk = event->tp_event->data; | |
1244 | if (!tk) | |
1245 | return -EINVAL; | |
1246 | ||
1247 | *fd_type = trace_kprobe_is_return(tk) ? BPF_FD_TYPE_KRETPROBE | |
1248 | : BPF_FD_TYPE_KPROBE; | |
1249 | if (tk->symbol) { | |
1250 | *symbol = tk->symbol; | |
1251 | *probe_offset = tk->rp.kp.offset; | |
1252 | *probe_addr = 0; | |
1253 | } else { | |
1254 | *symbol = NULL; | |
1255 | *probe_offset = 0; | |
1256 | *probe_addr = (unsigned long)tk->rp.kp.addr; | |
1257 | } | |
1258 | return 0; | |
1259 | } | |
07b139c8 | 1260 | #endif /* CONFIG_PERF_EVENTS */ |
50d78056 | 1261 | |
3fe3d619 ON |
1262 | /* |
1263 | * called by perf_trace_init() or __ftrace_set_clr_event() under event_mutex. | |
1264 | * | |
1265 | * kprobe_trace_self_tests_init() does enable_trace_probe/disable_trace_probe | |
1266 | * lockless, but we can't race with this __init function. | |
1267 | */ | |
2425bcb9 | 1268 | static int kprobe_register(struct trace_event_call *event, |
fbc1963d | 1269 | enum trace_reg type, void *data) |
2239291a | 1270 | { |
c31ffb3f | 1271 | struct trace_kprobe *tk = (struct trace_kprobe *)event->data; |
7f1d2f82 | 1272 | struct trace_event_file *file = data; |
1538f888 | 1273 | |
2239291a SR |
1274 | switch (type) { |
1275 | case TRACE_REG_REGISTER: | |
c31ffb3f | 1276 | return enable_trace_kprobe(tk, file); |
2239291a | 1277 | case TRACE_REG_UNREGISTER: |
c31ffb3f | 1278 | return disable_trace_kprobe(tk, file); |
2239291a SR |
1279 | |
1280 | #ifdef CONFIG_PERF_EVENTS | |
1281 | case TRACE_REG_PERF_REGISTER: | |
c31ffb3f | 1282 | return enable_trace_kprobe(tk, NULL); |
2239291a | 1283 | case TRACE_REG_PERF_UNREGISTER: |
c31ffb3f | 1284 | return disable_trace_kprobe(tk, NULL); |
ceec0b6f JO |
1285 | case TRACE_REG_PERF_OPEN: |
1286 | case TRACE_REG_PERF_CLOSE: | |
489c75c3 JO |
1287 | case TRACE_REG_PERF_ADD: |
1288 | case TRACE_REG_PERF_DEL: | |
ceec0b6f | 1289 | return 0; |
2239291a SR |
1290 | #endif |
1291 | } | |
1292 | return 0; | |
1293 | } | |
50d78056 | 1294 | |
3da0f180 | 1295 | static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs) |
50d78056 | 1296 | { |
c31ffb3f | 1297 | struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp); |
9802d865 | 1298 | int ret = 0; |
e08d1c65 | 1299 | |
a7636d9e | 1300 | raw_cpu_inc(*tk->nhit); |
48182bd2 | 1301 | |
c31ffb3f NK |
1302 | if (tk->tp.flags & TP_FLAG_TRACE) |
1303 | kprobe_trace_func(tk, regs); | |
07b139c8 | 1304 | #ifdef CONFIG_PERF_EVENTS |
c31ffb3f | 1305 | if (tk->tp.flags & TP_FLAG_PROFILE) |
9802d865 | 1306 | ret = kprobe_perf_func(tk, regs); |
07b139c8 | 1307 | #endif |
9802d865 | 1308 | return ret; |
50d78056 | 1309 | } |
3da0f180 | 1310 | NOKPROBE_SYMBOL(kprobe_dispatcher); |
50d78056 | 1311 | |
3da0f180 MH |
1312 | static int |
1313 | kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs) | |
50d78056 | 1314 | { |
c31ffb3f | 1315 | struct trace_kprobe *tk = container_of(ri->rp, struct trace_kprobe, rp); |
50d78056 | 1316 | |
a7636d9e | 1317 | raw_cpu_inc(*tk->nhit); |
48182bd2 | 1318 | |
c31ffb3f NK |
1319 | if (tk->tp.flags & TP_FLAG_TRACE) |
1320 | kretprobe_trace_func(tk, ri, regs); | |
07b139c8 | 1321 | #ifdef CONFIG_PERF_EVENTS |
c31ffb3f NK |
1322 | if (tk->tp.flags & TP_FLAG_PROFILE) |
1323 | kretprobe_perf_func(tk, ri, regs); | |
07b139c8 | 1324 | #endif |
50d78056 MH |
1325 | return 0; /* We don't tweek kernel, so just return 0 */ |
1326 | } | |
3da0f180 | 1327 | NOKPROBE_SYMBOL(kretprobe_dispatcher); |
e08d1c65 | 1328 | |
a9a57763 SR |
1329 | static struct trace_event_functions kretprobe_funcs = { |
1330 | .trace = print_kretprobe_event | |
1331 | }; | |
1332 | ||
1333 | static struct trace_event_functions kprobe_funcs = { | |
1334 | .trace = print_kprobe_event | |
1335 | }; | |
1336 | ||
e12f03d7 SL |
1337 | static inline void init_trace_event_call(struct trace_kprobe *tk, |
1338 | struct trace_event_call *call) | |
413d37d1 | 1339 | { |
ffb9f995 | 1340 | INIT_LIST_HEAD(&call->class->fields); |
c31ffb3f | 1341 | if (trace_kprobe_is_return(tk)) { |
80decc70 | 1342 | call->event.funcs = &kretprobe_funcs; |
2e33af02 | 1343 | call->class->define_fields = kretprobe_event_define_fields; |
413d37d1 | 1344 | } else { |
80decc70 | 1345 | call->event.funcs = &kprobe_funcs; |
2e33af02 | 1346 | call->class->define_fields = kprobe_event_define_fields; |
413d37d1 | 1347 | } |
e12f03d7 SL |
1348 | |
1349 | call->flags = TRACE_EVENT_FL_KPROBE; | |
1350 | call->class->reg = kprobe_register; | |
1351 | call->data = tk; | |
1352 | } | |
1353 | ||
1354 | static int register_kprobe_event(struct trace_kprobe *tk) | |
1355 | { | |
1356 | struct trace_event_call *call = &tk->tp.call; | |
1357 | int ret = 0; | |
1358 | ||
1359 | init_trace_event_call(tk, call); | |
1360 | ||
0a46c854 | 1361 | if (traceprobe_set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) |
a342a028 | 1362 | return -ENOMEM; |
9023c930 | 1363 | ret = register_trace_event(&call->event); |
32c0edae | 1364 | if (!ret) { |
a342a028 | 1365 | kfree(call->print_fmt); |
ff50d991 | 1366 | return -ENODEV; |
a342a028 | 1367 | } |
413d37d1 | 1368 | ret = trace_add_event_call(call); |
ff50d991 | 1369 | if (ret) { |
de7b2973 | 1370 | pr_info("Failed to register kprobe event: %s\n", |
687fcc4a | 1371 | trace_event_name(call)); |
a342a028 | 1372 | kfree(call->print_fmt); |
9023c930 | 1373 | unregister_trace_event(&call->event); |
ff50d991 | 1374 | } |
413d37d1 MH |
1375 | return ret; |
1376 | } | |
1377 | ||
c31ffb3f | 1378 | static int unregister_kprobe_event(struct trace_kprobe *tk) |
413d37d1 | 1379 | { |
40c32592 SRRH |
1380 | int ret; |
1381 | ||
ff50d991 | 1382 | /* tp->event is unregistered in trace_remove_event_call() */ |
c31ffb3f | 1383 | ret = trace_remove_event_call(&tk->tp.call); |
40c32592 | 1384 | if (!ret) |
c31ffb3f | 1385 | kfree(tk->tp.call.print_fmt); |
40c32592 | 1386 | return ret; |
413d37d1 MH |
1387 | } |
1388 | ||
e12f03d7 SL |
1389 | #ifdef CONFIG_PERF_EVENTS |
1390 | /* create a trace_kprobe, but don't add it to global lists */ | |
1391 | struct trace_event_call * | |
1392 | create_local_trace_kprobe(char *func, void *addr, unsigned long offs, | |
1393 | bool is_return) | |
1394 | { | |
1395 | struct trace_kprobe *tk; | |
1396 | int ret; | |
1397 | char *event; | |
1398 | ||
1399 | /* | |
6212dd29 | 1400 | * local trace_kprobes are not added to dyn_event, so they are never |
e12f03d7 SL |
1401 | * searched in find_trace_kprobe(). Therefore, there is no concern of |
1402 | * duplicated name here. | |
1403 | */ | |
1404 | event = func ? func : "DUMMY_EVENT"; | |
1405 | ||
1406 | tk = alloc_trace_kprobe(KPROBE_EVENT_SYSTEM, event, (void *)addr, func, | |
1407 | offs, 0 /* maxactive */, 0 /* nargs */, | |
1408 | is_return); | |
1409 | ||
1410 | if (IS_ERR(tk)) { | |
1411 | pr_info("Failed to allocate trace_probe.(%d)\n", | |
1412 | (int)PTR_ERR(tk)); | |
1413 | return ERR_CAST(tk); | |
1414 | } | |
1415 | ||
1416 | init_trace_event_call(tk, &tk->tp.call); | |
1417 | ||
0a46c854 | 1418 | if (traceprobe_set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) { |
e12f03d7 SL |
1419 | ret = -ENOMEM; |
1420 | goto error; | |
1421 | } | |
1422 | ||
1423 | ret = __register_trace_kprobe(tk); | |
0fc8c358 JO |
1424 | if (ret < 0) { |
1425 | kfree(tk->tp.call.print_fmt); | |
e12f03d7 | 1426 | goto error; |
0fc8c358 | 1427 | } |
e12f03d7 SL |
1428 | |
1429 | return &tk->tp.call; | |
1430 | error: | |
1431 | free_trace_kprobe(tk); | |
1432 | return ERR_PTR(ret); | |
1433 | } | |
1434 | ||
1435 | void destroy_local_trace_kprobe(struct trace_event_call *event_call) | |
1436 | { | |
1437 | struct trace_kprobe *tk; | |
1438 | ||
1439 | tk = container_of(event_call, struct trace_kprobe, tp.call); | |
1440 | ||
1441 | if (trace_probe_is_enabled(&tk->tp)) { | |
1442 | WARN_ON(1); | |
1443 | return; | |
1444 | } | |
1445 | ||
1446 | __unregister_trace_kprobe(tk); | |
0fc8c358 JO |
1447 | |
1448 | kfree(tk->tp.call.print_fmt); | |
e12f03d7 SL |
1449 | free_trace_kprobe(tk); |
1450 | } | |
1451 | #endif /* CONFIG_PERF_EVENTS */ | |
1452 | ||
8434dc93 | 1453 | /* Make a tracefs interface for controlling probe points */ |
413d37d1 MH |
1454 | static __init int init_kprobe_trace(void) |
1455 | { | |
1456 | struct dentry *d_tracer; | |
1457 | struct dentry *entry; | |
6212dd29 MH |
1458 | int ret; |
1459 | ||
1460 | ret = dyn_event_register(&trace_kprobe_ops); | |
1461 | if (ret) | |
1462 | return ret; | |
413d37d1 | 1463 | |
c31ffb3f | 1464 | if (register_module_notifier(&trace_kprobe_module_nb)) |
61424318 MH |
1465 | return -EINVAL; |
1466 | ||
413d37d1 | 1467 | d_tracer = tracing_init_dentry(); |
14a5ae40 | 1468 | if (IS_ERR(d_tracer)) |
413d37d1 MH |
1469 | return 0; |
1470 | ||
8434dc93 | 1471 | entry = tracefs_create_file("kprobe_events", 0644, d_tracer, |
413d37d1 MH |
1472 | NULL, &kprobe_events_ops); |
1473 | ||
cd7e7bd5 | 1474 | /* Event list interface */ |
413d37d1 | 1475 | if (!entry) |
a395d6a7 | 1476 | pr_warn("Could not create tracefs 'kprobe_events' entry\n"); |
cd7e7bd5 MH |
1477 | |
1478 | /* Profile interface */ | |
8434dc93 | 1479 | entry = tracefs_create_file("kprobe_profile", 0444, d_tracer, |
cd7e7bd5 MH |
1480 | NULL, &kprobe_profile_ops); |
1481 | ||
1482 | if (!entry) | |
a395d6a7 | 1483 | pr_warn("Could not create tracefs 'kprobe_profile' entry\n"); |
413d37d1 MH |
1484 | return 0; |
1485 | } | |
1486 | fs_initcall(init_kprobe_trace); | |
1487 | ||
1488 | ||
1489 | #ifdef CONFIG_FTRACE_STARTUP_TEST | |
26a346f2 | 1490 | static __init struct trace_event_file * |
c31ffb3f | 1491 | find_trace_probe_file(struct trace_kprobe *tk, struct trace_array *tr) |
41a7dd42 | 1492 | { |
7f1d2f82 | 1493 | struct trace_event_file *file; |
41a7dd42 MH |
1494 | |
1495 | list_for_each_entry(file, &tr->events, list) | |
c31ffb3f | 1496 | if (file->event_call == &tk->tp.call) |
41a7dd42 MH |
1497 | return file; |
1498 | ||
1499 | return NULL; | |
1500 | } | |
1501 | ||
3fe3d619 | 1502 | /* |
c31ffb3f | 1503 | * Nobody but us can call enable_trace_kprobe/disable_trace_kprobe at this |
3fe3d619 ON |
1504 | * stage, we can do this lockless. |
1505 | */ | |
413d37d1 MH |
1506 | static __init int kprobe_trace_self_tests_init(void) |
1507 | { | |
231e36f4 | 1508 | int ret, warn = 0; |
413d37d1 | 1509 | int (*target)(int, int, int, int, int, int); |
c31ffb3f | 1510 | struct trace_kprobe *tk; |
7f1d2f82 | 1511 | struct trace_event_file *file; |
413d37d1 | 1512 | |
748ec3a2 YY |
1513 | if (tracing_is_disabled()) |
1514 | return -ENODEV; | |
1515 | ||
413d37d1 MH |
1516 | target = kprobe_trace_selftest_target; |
1517 | ||
1518 | pr_info("Testing kprobe tracing: "); | |
1519 | ||
6212dd29 MH |
1520 | ret = trace_run_command("p:testprobe kprobe_trace_selftest_target $stack $stack0 +0($stack)", |
1521 | create_or_delete_trace_kprobe); | |
231e36f4 | 1522 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1523 | pr_warn("error on probing function entry.\n"); |
231e36f4 MH |
1524 | warn++; |
1525 | } else { | |
1526 | /* Enable trace point */ | |
c31ffb3f NK |
1527 | tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM); |
1528 | if (WARN_ON_ONCE(tk == NULL)) { | |
41a7dd42 | 1529 | pr_warn("error on getting new probe.\n"); |
231e36f4 | 1530 | warn++; |
41a7dd42 | 1531 | } else { |
c31ffb3f | 1532 | file = find_trace_probe_file(tk, top_trace_array()); |
41a7dd42 MH |
1533 | if (WARN_ON_ONCE(file == NULL)) { |
1534 | pr_warn("error on getting probe file.\n"); | |
1535 | warn++; | |
1536 | } else | |
c31ffb3f | 1537 | enable_trace_kprobe(tk, file); |
41a7dd42 | 1538 | } |
231e36f4 | 1539 | } |
413d37d1 | 1540 | |
6212dd29 MH |
1541 | ret = trace_run_command("r:testprobe2 kprobe_trace_selftest_target $retval", |
1542 | create_or_delete_trace_kprobe); | |
231e36f4 | 1543 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1544 | pr_warn("error on probing function return.\n"); |
231e36f4 MH |
1545 | warn++; |
1546 | } else { | |
1547 | /* Enable trace point */ | |
c31ffb3f NK |
1548 | tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM); |
1549 | if (WARN_ON_ONCE(tk == NULL)) { | |
41a7dd42 | 1550 | pr_warn("error on getting 2nd new probe.\n"); |
231e36f4 | 1551 | warn++; |
41a7dd42 | 1552 | } else { |
c31ffb3f | 1553 | file = find_trace_probe_file(tk, top_trace_array()); |
41a7dd42 MH |
1554 | if (WARN_ON_ONCE(file == NULL)) { |
1555 | pr_warn("error on getting probe file.\n"); | |
1556 | warn++; | |
1557 | } else | |
c31ffb3f | 1558 | enable_trace_kprobe(tk, file); |
41a7dd42 | 1559 | } |
231e36f4 MH |
1560 | } |
1561 | ||
1562 | if (warn) | |
1563 | goto end; | |
413d37d1 MH |
1564 | |
1565 | ret = target(1, 2, 3, 4, 5, 6); | |
1566 | ||
d4d7ccc8 MN |
1567 | /* |
1568 | * Not expecting an error here, the check is only to prevent the | |
1569 | * optimizer from removing the call to target() as otherwise there | |
1570 | * are no side-effects and the call is never performed. | |
1571 | */ | |
1572 | if (ret != 21) | |
1573 | warn++; | |
1574 | ||
02ca1521 | 1575 | /* Disable trace points before removing it */ |
c31ffb3f NK |
1576 | tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM); |
1577 | if (WARN_ON_ONCE(tk == NULL)) { | |
41a7dd42 | 1578 | pr_warn("error on getting test probe.\n"); |
02ca1521 | 1579 | warn++; |
41a7dd42 | 1580 | } else { |
d4d7ccc8 MN |
1581 | if (trace_kprobe_nhit(tk) != 1) { |
1582 | pr_warn("incorrect number of testprobe hits\n"); | |
1583 | warn++; | |
1584 | } | |
1585 | ||
c31ffb3f | 1586 | file = find_trace_probe_file(tk, top_trace_array()); |
41a7dd42 MH |
1587 | if (WARN_ON_ONCE(file == NULL)) { |
1588 | pr_warn("error on getting probe file.\n"); | |
1589 | warn++; | |
1590 | } else | |
c31ffb3f | 1591 | disable_trace_kprobe(tk, file); |
41a7dd42 | 1592 | } |
02ca1521 | 1593 | |
c31ffb3f NK |
1594 | tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM); |
1595 | if (WARN_ON_ONCE(tk == NULL)) { | |
41a7dd42 | 1596 | pr_warn("error on getting 2nd test probe.\n"); |
02ca1521 | 1597 | warn++; |
41a7dd42 | 1598 | } else { |
d4d7ccc8 MN |
1599 | if (trace_kprobe_nhit(tk) != 1) { |
1600 | pr_warn("incorrect number of testprobe2 hits\n"); | |
1601 | warn++; | |
1602 | } | |
1603 | ||
c31ffb3f | 1604 | file = find_trace_probe_file(tk, top_trace_array()); |
41a7dd42 MH |
1605 | if (WARN_ON_ONCE(file == NULL)) { |
1606 | pr_warn("error on getting probe file.\n"); | |
1607 | warn++; | |
1608 | } else | |
c31ffb3f | 1609 | disable_trace_kprobe(tk, file); |
41a7dd42 | 1610 | } |
02ca1521 | 1611 | |
6212dd29 | 1612 | ret = trace_run_command("-:testprobe", create_or_delete_trace_kprobe); |
231e36f4 | 1613 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1614 | pr_warn("error on deleting a probe.\n"); |
231e36f4 MH |
1615 | warn++; |
1616 | } | |
1617 | ||
6212dd29 | 1618 | ret = trace_run_command("-:testprobe2", create_or_delete_trace_kprobe); |
231e36f4 | 1619 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1620 | pr_warn("error on deleting a probe.\n"); |
231e36f4 MH |
1621 | warn++; |
1622 | } | |
413d37d1 | 1623 | |
231e36f4 | 1624 | end: |
6212dd29 MH |
1625 | ret = dyn_events_release_all(&trace_kprobe_ops); |
1626 | if (WARN_ON_ONCE(ret)) { | |
1627 | pr_warn("error on cleaning up probes.\n"); | |
1628 | warn++; | |
1629 | } | |
30e7d894 TG |
1630 | /* |
1631 | * Wait for the optimizer work to finish. Otherwise it might fiddle | |
1632 | * with probes in already freed __init text. | |
1633 | */ | |
1634 | wait_for_kprobe_optimizer(); | |
231e36f4 MH |
1635 | if (warn) |
1636 | pr_cont("NG: Some tests are failed. Please check them.\n"); | |
1637 | else | |
1638 | pr_cont("OK\n"); | |
413d37d1 MH |
1639 | return 0; |
1640 | } | |
1641 | ||
1642 | late_initcall(kprobe_trace_self_tests_init); | |
1643 | ||
1644 | #endif |