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Commit | Line | Data |
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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 | ||
413d37d1 | 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 | ||
da34634f | 224 | if (!event || !is_good_name(event)) { |
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 | |
da34634f | 234 | if (!group || !is_good_name(group)) { |
6f3cf440 | 235 | ret = -EINVAL; |
f52487e9 | 236 | goto error; |
6f3cf440 MH |
237 | } |
238 | ||
c31ffb3f NK |
239 | tk->tp.class.system = kstrdup(group, GFP_KERNEL); |
240 | if (!tk->tp.class.system) | |
f52487e9 MH |
241 | goto error; |
242 | ||
6212dd29 | 243 | dyn_event_init(&tk->devent, &trace_kprobe_ops); |
c31ffb3f NK |
244 | INIT_LIST_HEAD(&tk->tp.files); |
245 | return tk; | |
413d37d1 | 246 | error: |
c31ffb3f NK |
247 | kfree(tk->tp.call.name); |
248 | kfree(tk->symbol); | |
a7636d9e | 249 | free_percpu(tk->nhit); |
c31ffb3f | 250 | kfree(tk); |
6f3cf440 | 251 | return ERR_PTR(ret); |
413d37d1 MH |
252 | } |
253 | ||
c31ffb3f | 254 | static void free_trace_kprobe(struct trace_kprobe *tk) |
413d37d1 MH |
255 | { |
256 | int i; | |
257 | ||
6212dd29 MH |
258 | if (!tk) |
259 | return; | |
260 | ||
c31ffb3f NK |
261 | for (i = 0; i < tk->tp.nr_args; i++) |
262 | traceprobe_free_probe_arg(&tk->tp.args[i]); | |
413d37d1 | 263 | |
c31ffb3f NK |
264 | kfree(tk->tp.call.class->system); |
265 | kfree(tk->tp.call.name); | |
266 | kfree(tk->symbol); | |
a7636d9e | 267 | free_percpu(tk->nhit); |
c31ffb3f | 268 | kfree(tk); |
413d37d1 MH |
269 | } |
270 | ||
c31ffb3f NK |
271 | static struct trace_kprobe *find_trace_kprobe(const char *event, |
272 | const char *group) | |
413d37d1 | 273 | { |
6212dd29 | 274 | struct dyn_event *pos; |
c31ffb3f | 275 | struct trace_kprobe *tk; |
413d37d1 | 276 | |
6212dd29 | 277 | for_each_trace_kprobe(tk, pos) |
687fcc4a | 278 | if (strcmp(trace_event_name(&tk->tp.call), event) == 0 && |
c31ffb3f NK |
279 | strcmp(tk->tp.call.class->system, group) == 0) |
280 | return tk; | |
413d37d1 MH |
281 | return NULL; |
282 | } | |
283 | ||
87107a25 SRV |
284 | static inline int __enable_trace_kprobe(struct trace_kprobe *tk) |
285 | { | |
286 | int ret = 0; | |
287 | ||
288 | if (trace_probe_is_registered(&tk->tp) && !trace_kprobe_has_gone(tk)) { | |
289 | if (trace_kprobe_is_return(tk)) | |
290 | ret = enable_kretprobe(&tk->rp); | |
291 | else | |
292 | ret = enable_kprobe(&tk->rp.kp); | |
293 | } | |
294 | ||
295 | return ret; | |
296 | } | |
297 | ||
41a7dd42 MH |
298 | /* |
299 | * Enable trace_probe | |
300 | * if the file is NULL, enable "perf" handler, or enable "trace" handler. | |
301 | */ | |
302 | static int | |
7f1d2f82 | 303 | enable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file) |
1538f888 | 304 | { |
87107a25 | 305 | struct event_file_link *link; |
1538f888 MH |
306 | int ret = 0; |
307 | ||
41a7dd42 | 308 | if (file) { |
b04d52e3 ON |
309 | link = kmalloc(sizeof(*link), GFP_KERNEL); |
310 | if (!link) { | |
41a7dd42 | 311 | ret = -ENOMEM; |
3fe3d619 | 312 | goto out; |
41a7dd42 | 313 | } |
41a7dd42 | 314 | |
b04d52e3 | 315 | link->file = file; |
c31ffb3f | 316 | list_add_tail_rcu(&link->list, &tk->tp.files); |
41a7dd42 | 317 | |
c31ffb3f | 318 | tk->tp.flags |= TP_FLAG_TRACE; |
87107a25 SRV |
319 | ret = __enable_trace_kprobe(tk); |
320 | if (ret) { | |
321 | list_del_rcu(&link->list); | |
57ea2a34 AS |
322 | kfree(link); |
323 | tk->tp.flags &= ~TP_FLAG_TRACE; | |
57ea2a34 | 324 | } |
87107a25 SRV |
325 | |
326 | } else { | |
327 | tk->tp.flags |= TP_FLAG_PROFILE; | |
328 | ret = __enable_trace_kprobe(tk); | |
329 | if (ret) | |
330 | tk->tp.flags &= ~TP_FLAG_PROFILE; | |
57ea2a34 | 331 | } |
3fe3d619 | 332 | out: |
1538f888 MH |
333 | return ret; |
334 | } | |
335 | ||
41a7dd42 MH |
336 | /* |
337 | * Disable trace_probe | |
338 | * if the file is NULL, disable "perf" handler, or disable "trace" handler. | |
339 | */ | |
340 | static int | |
7f1d2f82 | 341 | disable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file) |
1538f888 | 342 | { |
a232e270 MH |
343 | struct event_file_link *link = NULL; |
344 | int wait = 0; | |
41a7dd42 MH |
345 | int ret = 0; |
346 | ||
41a7dd42 | 347 | if (file) { |
c31ffb3f | 348 | link = find_event_file_link(&tk->tp, file); |
b04d52e3 | 349 | if (!link) { |
41a7dd42 | 350 | ret = -EINVAL; |
3fe3d619 | 351 | goto out; |
41a7dd42 MH |
352 | } |
353 | ||
b04d52e3 | 354 | list_del_rcu(&link->list); |
a232e270 | 355 | wait = 1; |
c31ffb3f | 356 | if (!list_empty(&tk->tp.files)) |
b04d52e3 | 357 | goto out; |
41a7dd42 | 358 | |
c31ffb3f | 359 | tk->tp.flags &= ~TP_FLAG_TRACE; |
41a7dd42 | 360 | } else |
c31ffb3f | 361 | tk->tp.flags &= ~TP_FLAG_PROFILE; |
41a7dd42 | 362 | |
c31ffb3f NK |
363 | if (!trace_probe_is_enabled(&tk->tp) && trace_probe_is_registered(&tk->tp)) { |
364 | if (trace_kprobe_is_return(tk)) | |
365 | disable_kretprobe(&tk->rp); | |
1538f888 | 366 | else |
c31ffb3f | 367 | disable_kprobe(&tk->rp.kp); |
a232e270 | 368 | wait = 1; |
1538f888 | 369 | } |
e12f03d7 SL |
370 | |
371 | /* | |
372 | * if tk is not added to any list, it must be a local trace_kprobe | |
373 | * created with perf_event_open. We don't need to wait for these | |
374 | * trace_kprobes | |
375 | */ | |
6212dd29 | 376 | if (list_empty(&tk->devent.list)) |
e12f03d7 | 377 | wait = 0; |
3fe3d619 | 378 | out: |
a232e270 MH |
379 | if (wait) { |
380 | /* | |
381 | * Synchronize with kprobe_trace_func/kretprobe_trace_func | |
382 | * to ensure disabled (all running handlers are finished). | |
383 | * This is not only for kfree(), but also the caller, | |
384 | * trace_remove_event_call() supposes it for releasing | |
385 | * event_call related objects, which will be accessed in | |
386 | * the kprobe_trace_func/kretprobe_trace_func. | |
387 | */ | |
74401729 | 388 | synchronize_rcu(); |
a232e270 MH |
389 | kfree(link); /* Ignored if link == NULL */ |
390 | } | |
391 | ||
41a7dd42 | 392 | return ret; |
1538f888 MH |
393 | } |
394 | ||
45408c4f MH |
395 | #if defined(CONFIG_KPROBES_ON_FTRACE) && \ |
396 | !defined(CONFIG_KPROBE_EVENTS_ON_NOTRACE) | |
397 | static bool within_notrace_func(struct trace_kprobe *tk) | |
398 | { | |
399 | unsigned long offset, size, addr; | |
400 | ||
401 | addr = trace_kprobe_address(tk); | |
6bc6c77c MH |
402 | if (!addr || !kallsyms_lookup_size_offset(addr, &size, &offset)) |
403 | return false; | |
45408c4f | 404 | |
9161a864 MH |
405 | /* Get the entry address of the target function */ |
406 | addr -= offset; | |
407 | ||
408 | /* | |
409 | * Since ftrace_location_range() does inclusive range check, we need | |
410 | * to subtract 1 byte from the end address. | |
411 | */ | |
412 | return !ftrace_location_range(addr, addr + size - 1); | |
45408c4f MH |
413 | } |
414 | #else | |
415 | #define within_notrace_func(tk) (false) | |
416 | #endif | |
417 | ||
61424318 | 418 | /* Internal register function - just handle k*probes and flags */ |
c31ffb3f | 419 | static int __register_trace_kprobe(struct trace_kprobe *tk) |
413d37d1 | 420 | { |
a6682814 | 421 | int i, ret; |
61424318 | 422 | |
c31ffb3f | 423 | if (trace_probe_is_registered(&tk->tp)) |
61424318 MH |
424 | return -EINVAL; |
425 | ||
45408c4f MH |
426 | if (within_notrace_func(tk)) { |
427 | pr_warn("Could not probe notrace function %s\n", | |
428 | trace_kprobe_symbol(tk)); | |
429 | return -EINVAL; | |
430 | } | |
431 | ||
a6682814 MH |
432 | for (i = 0; i < tk->tp.nr_args; i++) { |
433 | ret = traceprobe_update_arg(&tk->tp.args[i]); | |
434 | if (ret) | |
435 | return ret; | |
436 | } | |
437 | ||
61424318 | 438 | /* Set/clear disabled flag according to tp->flag */ |
c31ffb3f NK |
439 | if (trace_probe_is_enabled(&tk->tp)) |
440 | tk->rp.kp.flags &= ~KPROBE_FLAG_DISABLED; | |
61424318 | 441 | else |
c31ffb3f | 442 | tk->rp.kp.flags |= KPROBE_FLAG_DISABLED; |
61424318 | 443 | |
c31ffb3f NK |
444 | if (trace_kprobe_is_return(tk)) |
445 | ret = register_kretprobe(&tk->rp); | |
413d37d1 | 446 | else |
c31ffb3f | 447 | ret = register_kprobe(&tk->rp.kp); |
61424318 | 448 | |
59158ec4 | 449 | if (ret == 0) { |
c31ffb3f | 450 | tk->tp.flags |= TP_FLAG_REGISTERED; |
59158ec4 MH |
451 | } else if (ret == -EILSEQ) { |
452 | pr_warn("Probing address(0x%p) is not an instruction boundary.\n", | |
453 | tk->rp.kp.addr); | |
454 | ret = -EINVAL; | |
61424318 | 455 | } |
61424318 MH |
456 | return ret; |
457 | } | |
458 | ||
459 | /* Internal unregister function - just handle k*probes and flags */ | |
c31ffb3f | 460 | static void __unregister_trace_kprobe(struct trace_kprobe *tk) |
61424318 | 461 | { |
c31ffb3f NK |
462 | if (trace_probe_is_registered(&tk->tp)) { |
463 | if (trace_kprobe_is_return(tk)) | |
464 | unregister_kretprobe(&tk->rp); | |
61424318 | 465 | else |
c31ffb3f NK |
466 | unregister_kprobe(&tk->rp.kp); |
467 | tk->tp.flags &= ~TP_FLAG_REGISTERED; | |
61424318 | 468 | /* Cleanup kprobe for reuse */ |
c31ffb3f NK |
469 | if (tk->rp.kp.symbol_name) |
470 | tk->rp.kp.addr = NULL; | |
61424318 MH |
471 | } |
472 | } | |
473 | ||
6212dd29 | 474 | /* Unregister a trace_probe and probe_event */ |
c31ffb3f | 475 | static int unregister_trace_kprobe(struct trace_kprobe *tk) |
61424318 | 476 | { |
02ca1521 | 477 | /* Enabled event can not be unregistered */ |
c31ffb3f | 478 | if (trace_probe_is_enabled(&tk->tp)) |
02ca1521 MH |
479 | return -EBUSY; |
480 | ||
40c32592 | 481 | /* Will fail if probe is being used by ftrace or perf */ |
c31ffb3f | 482 | if (unregister_kprobe_event(tk)) |
40c32592 SRRH |
483 | return -EBUSY; |
484 | ||
c31ffb3f | 485 | __unregister_trace_kprobe(tk); |
6212dd29 | 486 | dyn_event_remove(&tk->devent); |
02ca1521 MH |
487 | |
488 | return 0; | |
413d37d1 MH |
489 | } |
490 | ||
491 | /* Register a trace_probe and probe_event */ | |
c31ffb3f | 492 | static int register_trace_kprobe(struct trace_kprobe *tk) |
413d37d1 | 493 | { |
c31ffb3f | 494 | struct trace_kprobe *old_tk; |
413d37d1 MH |
495 | int ret; |
496 | ||
6212dd29 | 497 | mutex_lock(&event_mutex); |
413d37d1 | 498 | |
61424318 | 499 | /* Delete old (same name) event if exist */ |
687fcc4a | 500 | old_tk = find_trace_kprobe(trace_event_name(&tk->tp.call), |
de7b2973 | 501 | tk->tp.call.class->system); |
c31ffb3f NK |
502 | if (old_tk) { |
503 | ret = unregister_trace_kprobe(old_tk); | |
02ca1521 MH |
504 | if (ret < 0) |
505 | goto end; | |
c31ffb3f | 506 | free_trace_kprobe(old_tk); |
2d5e067e | 507 | } |
61424318 MH |
508 | |
509 | /* Register new event */ | |
c31ffb3f | 510 | ret = register_kprobe_event(tk); |
2d5e067e | 511 | if (ret) { |
a395d6a7 | 512 | pr_warn("Failed to register probe event(%d)\n", ret); |
2d5e067e MH |
513 | goto end; |
514 | } | |
515 | ||
61424318 | 516 | /* Register k*probe */ |
c31ffb3f | 517 | ret = __register_trace_kprobe(tk); |
59158ec4 MH |
518 | if (ret == -ENOENT && !trace_kprobe_module_exist(tk)) { |
519 | pr_warn("This probe might be able to register after target module is loaded. Continue.\n"); | |
520 | ret = 0; | |
521 | } | |
522 | ||
61424318 | 523 | if (ret < 0) |
c31ffb3f | 524 | unregister_kprobe_event(tk); |
61424318 | 525 | else |
6212dd29 | 526 | dyn_event_add(&tk->devent); |
61424318 | 527 | |
413d37d1 | 528 | end: |
6212dd29 | 529 | mutex_unlock(&event_mutex); |
413d37d1 MH |
530 | return ret; |
531 | } | |
532 | ||
61424318 | 533 | /* Module notifier call back, checking event on the module */ |
c31ffb3f | 534 | static int trace_kprobe_module_callback(struct notifier_block *nb, |
61424318 MH |
535 | unsigned long val, void *data) |
536 | { | |
537 | struct module *mod = data; | |
6212dd29 | 538 | struct dyn_event *pos; |
c31ffb3f | 539 | struct trace_kprobe *tk; |
61424318 MH |
540 | int ret; |
541 | ||
542 | if (val != MODULE_STATE_COMING) | |
543 | return NOTIFY_DONE; | |
544 | ||
545 | /* Update probes on coming module */ | |
6212dd29 MH |
546 | mutex_lock(&event_mutex); |
547 | for_each_trace_kprobe(tk, pos) { | |
c31ffb3f | 548 | if (trace_kprobe_within_module(tk, mod)) { |
02ca1521 | 549 | /* Don't need to check busy - this should have gone. */ |
c31ffb3f NK |
550 | __unregister_trace_kprobe(tk); |
551 | ret = __register_trace_kprobe(tk); | |
61424318 | 552 | if (ret) |
a395d6a7 JP |
553 | pr_warn("Failed to re-register probe %s on %s: %d\n", |
554 | trace_event_name(&tk->tp.call), | |
555 | mod->name, ret); | |
61424318 MH |
556 | } |
557 | } | |
6212dd29 | 558 | mutex_unlock(&event_mutex); |
61424318 MH |
559 | |
560 | return NOTIFY_DONE; | |
561 | } | |
562 | ||
c31ffb3f NK |
563 | static struct notifier_block trace_kprobe_module_nb = { |
564 | .notifier_call = trace_kprobe_module_callback, | |
61424318 MH |
565 | .priority = 1 /* Invoked after kprobe module callback */ |
566 | }; | |
567 | ||
fca18a47 NR |
568 | /* Convert certain expected symbols into '_' when generating event names */ |
569 | static inline void sanitize_event_name(char *name) | |
570 | { | |
571 | while (*name++ != '\0') | |
572 | if (*name == ':' || *name == '.') | |
573 | *name = '_'; | |
574 | } | |
575 | ||
6212dd29 | 576 | static int trace_kprobe_create(int argc, const char *argv[]) |
413d37d1 MH |
577 | { |
578 | /* | |
579 | * Argument syntax: | |
696ced4f AC |
580 | * - Add kprobe: |
581 | * p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS] | |
582 | * - Add kretprobe: | |
583 | * r[MAXACTIVE][:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS] | |
413d37d1 | 584 | * Fetch args: |
2e06ff63 MH |
585 | * $retval : fetch return value |
586 | * $stack : fetch stack address | |
587 | * $stackN : fetch Nth of stack (N:0-) | |
35abb67d | 588 | * $comm : fetch current task comm |
413d37d1 MH |
589 | * @ADDR : fetch memory at ADDR (ADDR should be in kernel) |
590 | * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol) | |
591 | * %REG : fetch register REG | |
93ccae7a | 592 | * Dereferencing memory fetch: |
413d37d1 | 593 | * +|-offs(ARG) : fetch memory at ARG +|- offs address. |
eca0d916 MH |
594 | * Alias name of args: |
595 | * NAME=FETCHARG : set NAME as alias of FETCHARG. | |
93ccae7a MH |
596 | * Type of args: |
597 | * FETCHARG:TYPE : use TYPE instead of unsigned long. | |
413d37d1 | 598 | */ |
c31ffb3f | 599 | struct trace_kprobe *tk; |
6212dd29 MH |
600 | int i, len, ret = 0; |
601 | bool is_return = false; | |
602 | char *symbol = NULL, *tmp = NULL; | |
603 | const char *event = NULL, *group = KPROBE_EVENT_SYSTEM; | |
696ced4f | 604 | int maxactive = 0; |
c5d343b6 | 605 | long offset = 0; |
413d37d1 | 606 | void *addr = NULL; |
4a846b44 | 607 | char buf[MAX_EVENT_NAME_LEN]; |
a1303af5 | 608 | unsigned int flags = TPARG_FL_KERNEL; |
413d37d1 | 609 | |
8b05a3a7 AR |
610 | switch (argv[0][0]) { |
611 | case 'r': | |
3a6b7666 | 612 | is_return = true; |
a1303af5 | 613 | flags |= TPARG_FL_RETURN; |
8b05a3a7 AR |
614 | break; |
615 | case 'p': | |
616 | break; | |
617 | default: | |
618 | return -ECANCELED; | |
619 | } | |
620 | if (argc < 2) | |
6212dd29 | 621 | return -ECANCELED; |
413d37d1 | 622 | |
696ced4f | 623 | event = strchr(&argv[0][1], ':'); |
6212dd29 | 624 | if (event) |
696ced4f | 625 | event++; |
6212dd29 | 626 | |
696ced4f | 627 | if (is_return && isdigit(argv[0][1])) { |
6212dd29 MH |
628 | if (event) |
629 | len = event - &argv[0][1] - 1; | |
630 | else | |
631 | len = strlen(&argv[0][1]); | |
632 | if (len > MAX_EVENT_NAME_LEN - 1) | |
633 | return -E2BIG; | |
634 | memcpy(buf, &argv[0][1], len); | |
635 | buf[len] = '\0'; | |
636 | ret = kstrtouint(buf, 0, &maxactive); | |
696ced4f AC |
637 | if (ret) { |
638 | pr_info("Failed to parse maxactive.\n"); | |
639 | return ret; | |
640 | } | |
641 | /* kretprobes instances are iterated over via a list. The | |
642 | * maximum should stay reasonable. | |
643 | */ | |
644 | if (maxactive > KRETPROBE_MAXACTIVE_MAX) { | |
645 | pr_info("Maxactive is too big (%d > %d).\n", | |
646 | maxactive, KRETPROBE_MAXACTIVE_MAX); | |
647 | return -E2BIG; | |
648 | } | |
649 | } | |
650 | ||
9e52b325 SD |
651 | /* try to parse an address. if that fails, try to read the |
652 | * input as a symbol. */ | |
653 | if (kstrtoul(argv[1], 0, (unsigned long *)&addr)) { | |
6212dd29 MH |
654 | /* Check whether uprobe event specified */ |
655 | if (strchr(argv[1], '/') && strchr(argv[1], ':')) | |
656 | return -ECANCELED; | |
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) { |
9e52b325 | 664 | pr_info("Failed to parse either an address or a symbol.\n"); |
6212dd29 | 665 | goto out; |
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)) { | |
d0e02579 | 670 | pr_info("Given offset is not valid for return probe.\n"); |
6212dd29 MH |
671 | ret = -EINVAL; |
672 | goto out; | |
e63cc239 | 673 | } |
413d37d1 | 674 | } |
a82378d8 | 675 | argc -= 2; argv += 2; |
413d37d1 | 676 | |
6212dd29 MH |
677 | if (event) { |
678 | ret = traceprobe_parse_event_name(&event, &group, buf); | |
679 | if (ret) | |
680 | goto out; | |
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 AC |
694 | tk = alloc_trace_kprobe(group, event, addr, symbol, offset, maxactive, |
695 | argc, is_return); | |
c31ffb3f | 696 | if (IS_ERR(tk)) { |
e63cc239 | 697 | pr_info("Failed to allocate trace_probe.(%d)\n", |
c31ffb3f | 698 | (int)PTR_ERR(tk)); |
6212dd29 MH |
699 | ret = PTR_ERR(tk); |
700 | goto out; | |
e63cc239 | 701 | } |
413d37d1 | 702 | |
413d37d1 | 703 | /* parse arguments */ |
a82378d8 | 704 | for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { |
6212dd29 MH |
705 | tmp = kstrdup(argv[i], GFP_KERNEL); |
706 | if (!tmp) { | |
ba8665d7 | 707 | ret = -ENOMEM; |
413d37d1 MH |
708 | goto error; |
709 | } | |
da34634f | 710 | |
6212dd29 MH |
711 | ret = traceprobe_parse_probe_arg(&tk->tp, i, tmp, flags); |
712 | kfree(tmp); | |
d00bbea9 | 713 | if (ret) |
413d37d1 MH |
714 | goto error; |
715 | } | |
413d37d1 | 716 | |
c31ffb3f | 717 | ret = register_trace_kprobe(tk); |
413d37d1 MH |
718 | if (ret) |
719 | goto error; | |
6212dd29 MH |
720 | out: |
721 | kfree(symbol); | |
722 | return ret; | |
413d37d1 MH |
723 | |
724 | error: | |
c31ffb3f | 725 | free_trace_kprobe(tk); |
6212dd29 | 726 | goto out; |
413d37d1 MH |
727 | } |
728 | ||
6212dd29 | 729 | static int create_or_delete_trace_kprobe(int argc, char **argv) |
413d37d1 | 730 | { |
6212dd29 | 731 | int ret; |
02ca1521 | 732 | |
6212dd29 MH |
733 | if (argv[0][0] == '-') |
734 | return dyn_event_release(argc, argv, &trace_kprobe_ops); | |
413d37d1 | 735 | |
6212dd29 MH |
736 | ret = trace_kprobe_create(argc, (const char **)argv); |
737 | return ret == -ECANCELED ? -EINVAL : ret; | |
413d37d1 MH |
738 | } |
739 | ||
6212dd29 | 740 | static int trace_kprobe_release(struct dyn_event *ev) |
413d37d1 | 741 | { |
6212dd29 MH |
742 | struct trace_kprobe *tk = to_trace_kprobe(ev); |
743 | int ret = unregister_trace_kprobe(tk); | |
413d37d1 | 744 | |
6212dd29 MH |
745 | if (!ret) |
746 | free_trace_kprobe(tk); | |
747 | return ret; | |
413d37d1 MH |
748 | } |
749 | ||
6212dd29 | 750 | static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev) |
413d37d1 | 751 | { |
6212dd29 | 752 | struct trace_kprobe *tk = to_trace_kprobe(ev); |
93ccae7a | 753 | int i; |
413d37d1 | 754 | |
fa6f0cc7 | 755 | seq_putc(m, trace_kprobe_is_return(tk) ? 'r' : 'p'); |
de7b2973 | 756 | seq_printf(m, ":%s/%s", tk->tp.call.class->system, |
687fcc4a | 757 | trace_event_name(&tk->tp.call)); |
413d37d1 | 758 | |
c31ffb3f NK |
759 | if (!tk->symbol) |
760 | seq_printf(m, " 0x%p", tk->rp.kp.addr); | |
761 | else if (tk->rp.kp.offset) | |
762 | seq_printf(m, " %s+%u", trace_kprobe_symbol(tk), | |
763 | tk->rp.kp.offset); | |
413d37d1 | 764 | else |
c31ffb3f | 765 | seq_printf(m, " %s", trace_kprobe_symbol(tk)); |
413d37d1 | 766 | |
c31ffb3f NK |
767 | for (i = 0; i < tk->tp.nr_args; i++) |
768 | seq_printf(m, " %s=%s", tk->tp.args[i].name, tk->tp.args[i].comm); | |
fa6f0cc7 | 769 | seq_putc(m, '\n'); |
93ccae7a | 770 | |
413d37d1 MH |
771 | return 0; |
772 | } | |
773 | ||
6212dd29 MH |
774 | static int probes_seq_show(struct seq_file *m, void *v) |
775 | { | |
776 | struct dyn_event *ev = v; | |
777 | ||
778 | if (!is_trace_kprobe(ev)) | |
779 | return 0; | |
780 | ||
781 | return trace_kprobe_show(m, ev); | |
782 | } | |
783 | ||
413d37d1 | 784 | static const struct seq_operations probes_seq_op = { |
6212dd29 MH |
785 | .start = dyn_event_seq_start, |
786 | .next = dyn_event_seq_next, | |
787 | .stop = dyn_event_seq_stop, | |
413d37d1 MH |
788 | .show = probes_seq_show |
789 | }; | |
790 | ||
791 | static int probes_open(struct inode *inode, struct file *file) | |
792 | { | |
02ca1521 MH |
793 | int ret; |
794 | ||
795 | if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { | |
6212dd29 | 796 | ret = dyn_events_release_all(&trace_kprobe_ops); |
02ca1521 MH |
797 | if (ret < 0) |
798 | return ret; | |
799 | } | |
413d37d1 MH |
800 | |
801 | return seq_open(file, &probes_seq_op); | |
802 | } | |
803 | ||
413d37d1 MH |
804 | static ssize_t probes_write(struct file *file, const char __user *buffer, |
805 | size_t count, loff_t *ppos) | |
806 | { | |
7e465baa | 807 | return trace_parse_run_command(file, buffer, count, ppos, |
6212dd29 | 808 | create_or_delete_trace_kprobe); |
413d37d1 MH |
809 | } |
810 | ||
811 | static const struct file_operations kprobe_events_ops = { | |
812 | .owner = THIS_MODULE, | |
813 | .open = probes_open, | |
814 | .read = seq_read, | |
815 | .llseek = seq_lseek, | |
816 | .release = seq_release, | |
817 | .write = probes_write, | |
818 | }; | |
819 | ||
cd7e7bd5 MH |
820 | /* Probes profiling interfaces */ |
821 | static int probes_profile_seq_show(struct seq_file *m, void *v) | |
822 | { | |
6212dd29 MH |
823 | struct dyn_event *ev = v; |
824 | struct trace_kprobe *tk; | |
cd7e7bd5 | 825 | |
6212dd29 MH |
826 | if (!is_trace_kprobe(ev)) |
827 | return 0; | |
cd7e7bd5 | 828 | |
6212dd29 | 829 | tk = to_trace_kprobe(ev); |
de7b2973 | 830 | seq_printf(m, " %-44s %15lu %15lu\n", |
f18f97ac MN |
831 | trace_event_name(&tk->tp.call), |
832 | trace_kprobe_nhit(tk), | |
c31ffb3f | 833 | tk->rp.kp.nmissed); |
cd7e7bd5 MH |
834 | |
835 | return 0; | |
836 | } | |
837 | ||
838 | static const struct seq_operations profile_seq_op = { | |
6212dd29 MH |
839 | .start = dyn_event_seq_start, |
840 | .next = dyn_event_seq_next, | |
841 | .stop = dyn_event_seq_stop, | |
cd7e7bd5 MH |
842 | .show = probes_profile_seq_show |
843 | }; | |
844 | ||
845 | static int profile_open(struct inode *inode, struct file *file) | |
846 | { | |
847 | return seq_open(file, &profile_seq_op); | |
848 | } | |
849 | ||
850 | static const struct file_operations kprobe_profile_ops = { | |
851 | .owner = THIS_MODULE, | |
852 | .open = profile_open, | |
853 | .read = seq_read, | |
854 | .llseek = seq_lseek, | |
855 | .release = seq_release, | |
856 | }; | |
857 | ||
53305928 MH |
858 | /* Kprobe specific fetch functions */ |
859 | ||
860 | /* Return the length of string -- including null terminal byte */ | |
9178412d MH |
861 | static nokprobe_inline int |
862 | fetch_store_strlen(unsigned long addr) | |
53305928 MH |
863 | { |
864 | mm_segment_t old_fs; | |
865 | int ret, len = 0; | |
866 | u8 c; | |
867 | ||
868 | old_fs = get_fs(); | |
869 | set_fs(KERNEL_DS); | |
870 | pagefault_disable(); | |
871 | ||
872 | do { | |
873 | ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1); | |
874 | len++; | |
875 | } while (c && ret == 0 && len < MAX_STRING_SIZE); | |
876 | ||
877 | pagefault_enable(); | |
878 | set_fs(old_fs); | |
879 | ||
9178412d | 880 | return (ret < 0) ? ret : len; |
53305928 MH |
881 | } |
882 | ||
883 | /* | |
884 | * Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max | |
885 | * length and relative data location. | |
886 | */ | |
9178412d MH |
887 | static nokprobe_inline int |
888 | fetch_store_string(unsigned long addr, void *dest, void *base) | |
53305928 | 889 | { |
9178412d MH |
890 | int maxlen = get_loc_len(*(u32 *)dest); |
891 | u8 *dst = get_loc_data(dest, base); | |
53305928 MH |
892 | long ret; |
893 | ||
9178412d MH |
894 | if (unlikely(!maxlen)) |
895 | return -ENOMEM; | |
53305928 MH |
896 | /* |
897 | * Try to get string again, since the string can be changed while | |
898 | * probing. | |
899 | */ | |
900 | ret = strncpy_from_unsafe(dst, (void *)addr, maxlen); | |
901 | ||
9178412d MH |
902 | if (ret >= 0) |
903 | *(u32 *)dest = make_data_loc(ret, (void *)dst - base); | |
904 | return ret; | |
53305928 MH |
905 | } |
906 | ||
9b960a38 MH |
907 | static nokprobe_inline int |
908 | probe_mem_read(void *dest, void *src, size_t size) | |
909 | { | |
910 | return probe_kernel_read(dest, src, size); | |
911 | } | |
912 | ||
53305928 MH |
913 | /* Note that we don't verify it, since the code does not come from user space */ |
914 | static int | |
915 | process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest, | |
9178412d | 916 | void *base) |
53305928 MH |
917 | { |
918 | unsigned long val; | |
53305928 | 919 | |
a6682814 | 920 | retry: |
53305928 MH |
921 | /* 1st stage: get value from context */ |
922 | switch (code->op) { | |
923 | case FETCH_OP_REG: | |
924 | val = regs_get_register(regs, code->param); | |
925 | break; | |
926 | case FETCH_OP_STACK: | |
927 | val = regs_get_kernel_stack_nth(regs, code->param); | |
928 | break; | |
929 | case FETCH_OP_STACKP: | |
930 | val = kernel_stack_pointer(regs); | |
931 | break; | |
932 | case FETCH_OP_RETVAL: | |
933 | val = regs_return_value(regs); | |
934 | break; | |
935 | case FETCH_OP_IMM: | |
936 | val = code->immediate; | |
937 | break; | |
938 | case FETCH_OP_COMM: | |
939 | val = (unsigned long)current->comm; | |
940 | break; | |
a1303af5 MH |
941 | #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API |
942 | case FETCH_OP_ARG: | |
943 | val = regs_get_kernel_argument(regs, code->param); | |
944 | break; | |
945 | #endif | |
a6682814 MH |
946 | case FETCH_NOP_SYMBOL: /* Ignore a place holder */ |
947 | code++; | |
948 | goto retry; | |
53305928 MH |
949 | default: |
950 | return -EILSEQ; | |
951 | } | |
952 | code++; | |
953 | ||
9b960a38 | 954 | return process_fetch_insn_bottom(code, val, dest, base); |
53305928 MH |
955 | } |
956 | NOKPROBE_SYMBOL(process_fetch_insn) | |
957 | ||
413d37d1 | 958 | /* Kprobe handler */ |
3da0f180 | 959 | static nokprobe_inline void |
c31ffb3f | 960 | __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs, |
7f1d2f82 | 961 | struct trace_event_file *trace_file) |
413d37d1 | 962 | { |
93ccae7a | 963 | struct kprobe_trace_entry_head *entry; |
413d37d1 | 964 | struct ring_buffer_event *event; |
8f8ffe24 | 965 | struct ring_buffer *buffer; |
e09c8614 | 966 | int size, dsize, pc; |
413d37d1 | 967 | unsigned long irq_flags; |
2425bcb9 | 968 | struct trace_event_call *call = &tk->tp.call; |
413d37d1 | 969 | |
7f1d2f82 | 970 | WARN_ON(call != trace_file->event_call); |
41a7dd42 | 971 | |
09a5059a | 972 | if (trace_trigger_soft_disabled(trace_file)) |
13a1e4ae | 973 | return; |
b8820084 | 974 | |
413d37d1 MH |
975 | local_save_flags(irq_flags); |
976 | pc = preempt_count(); | |
977 | ||
c31ffb3f NK |
978 | dsize = __get_data_size(&tk->tp, regs); |
979 | size = sizeof(*entry) + tk->tp.size + dsize; | |
413d37d1 | 980 | |
7f1d2f82 | 981 | event = trace_event_buffer_lock_reserve(&buffer, trace_file, |
41a7dd42 MH |
982 | call->event.type, |
983 | size, irq_flags, pc); | |
413d37d1 | 984 | if (!event) |
1e12a4a7 | 985 | return; |
413d37d1 MH |
986 | |
987 | entry = ring_buffer_event_data(event); | |
c31ffb3f | 988 | entry->ip = (unsigned long)tk->rp.kp.addr; |
9178412d | 989 | store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize); |
413d37d1 | 990 | |
7f1d2f82 | 991 | event_trigger_unlock_commit_regs(trace_file, buffer, event, |
13a1e4ae | 992 | entry, irq_flags, pc, regs); |
413d37d1 MH |
993 | } |
994 | ||
3da0f180 | 995 | static void |
c31ffb3f | 996 | kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs) |
41a7dd42 | 997 | { |
b04d52e3 | 998 | struct event_file_link *link; |
41a7dd42 | 999 | |
c31ffb3f NK |
1000 | list_for_each_entry_rcu(link, &tk->tp.files, list) |
1001 | __kprobe_trace_func(tk, regs, link->file); | |
41a7dd42 | 1002 | } |
3da0f180 | 1003 | NOKPROBE_SYMBOL(kprobe_trace_func); |
41a7dd42 | 1004 | |
413d37d1 | 1005 | /* Kretprobe handler */ |
3da0f180 | 1006 | static nokprobe_inline void |
c31ffb3f | 1007 | __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, |
41a7dd42 | 1008 | struct pt_regs *regs, |
7f1d2f82 | 1009 | struct trace_event_file *trace_file) |
413d37d1 | 1010 | { |
93ccae7a | 1011 | struct kretprobe_trace_entry_head *entry; |
413d37d1 | 1012 | struct ring_buffer_event *event; |
8f8ffe24 | 1013 | struct ring_buffer *buffer; |
e09c8614 | 1014 | int size, pc, dsize; |
413d37d1 | 1015 | unsigned long irq_flags; |
2425bcb9 | 1016 | struct trace_event_call *call = &tk->tp.call; |
413d37d1 | 1017 | |
7f1d2f82 | 1018 | WARN_ON(call != trace_file->event_call); |
41a7dd42 | 1019 | |
09a5059a | 1020 | if (trace_trigger_soft_disabled(trace_file)) |
13a1e4ae | 1021 | return; |
b8820084 | 1022 | |
413d37d1 MH |
1023 | local_save_flags(irq_flags); |
1024 | pc = preempt_count(); | |
1025 | ||
c31ffb3f NK |
1026 | dsize = __get_data_size(&tk->tp, regs); |
1027 | size = sizeof(*entry) + tk->tp.size + dsize; | |
413d37d1 | 1028 | |
7f1d2f82 | 1029 | event = trace_event_buffer_lock_reserve(&buffer, trace_file, |
41a7dd42 MH |
1030 | call->event.type, |
1031 | size, irq_flags, pc); | |
413d37d1 | 1032 | if (!event) |
1e12a4a7 | 1033 | return; |
413d37d1 MH |
1034 | |
1035 | entry = ring_buffer_event_data(event); | |
c31ffb3f | 1036 | entry->func = (unsigned long)tk->rp.kp.addr; |
413d37d1 | 1037 | entry->ret_ip = (unsigned long)ri->ret_addr; |
9178412d | 1038 | store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize); |
413d37d1 | 1039 | |
7f1d2f82 | 1040 | event_trigger_unlock_commit_regs(trace_file, buffer, event, |
13a1e4ae | 1041 | entry, irq_flags, pc, regs); |
413d37d1 MH |
1042 | } |
1043 | ||
3da0f180 | 1044 | static void |
c31ffb3f | 1045 | kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, |
41a7dd42 MH |
1046 | struct pt_regs *regs) |
1047 | { | |
b04d52e3 | 1048 | struct event_file_link *link; |
41a7dd42 | 1049 | |
c31ffb3f NK |
1050 | list_for_each_entry_rcu(link, &tk->tp.files, list) |
1051 | __kretprobe_trace_func(tk, ri, regs, link->file); | |
41a7dd42 | 1052 | } |
3da0f180 | 1053 | NOKPROBE_SYMBOL(kretprobe_trace_func); |
41a7dd42 | 1054 | |
413d37d1 | 1055 | /* Event entry printers */ |
b62fdd97 | 1056 | static enum print_line_t |
a9a57763 SR |
1057 | print_kprobe_event(struct trace_iterator *iter, int flags, |
1058 | struct trace_event *event) | |
413d37d1 | 1059 | { |
93ccae7a | 1060 | struct kprobe_trace_entry_head *field; |
413d37d1 | 1061 | struct trace_seq *s = &iter->seq; |
eca0d916 | 1062 | struct trace_probe *tp; |
413d37d1 | 1063 | |
93ccae7a | 1064 | field = (struct kprobe_trace_entry_head *)iter->ent; |
80decc70 | 1065 | tp = container_of(event, struct trace_probe, call.event); |
413d37d1 | 1066 | |
687fcc4a | 1067 | trace_seq_printf(s, "%s: (", trace_event_name(&tp->call)); |
6e9f23d1 | 1068 | |
413d37d1 | 1069 | if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET)) |
85224da0 | 1070 | goto out; |
413d37d1 | 1071 | |
85224da0 | 1072 | trace_seq_putc(s, ')'); |
413d37d1 | 1073 | |
56de7630 MH |
1074 | if (print_probe_args(s, tp->args, tp->nr_args, |
1075 | (u8 *)&field[1], field) < 0) | |
1076 | goto out; | |
413d37d1 | 1077 | |
85224da0 SRRH |
1078 | trace_seq_putc(s, '\n'); |
1079 | out: | |
1080 | return trace_handle_return(s); | |
413d37d1 MH |
1081 | } |
1082 | ||
b62fdd97 | 1083 | static enum print_line_t |
a9a57763 SR |
1084 | print_kretprobe_event(struct trace_iterator *iter, int flags, |
1085 | struct trace_event *event) | |
413d37d1 | 1086 | { |
93ccae7a | 1087 | struct kretprobe_trace_entry_head *field; |
413d37d1 | 1088 | struct trace_seq *s = &iter->seq; |
eca0d916 | 1089 | struct trace_probe *tp; |
413d37d1 | 1090 | |
93ccae7a | 1091 | field = (struct kretprobe_trace_entry_head *)iter->ent; |
80decc70 | 1092 | tp = container_of(event, struct trace_probe, call.event); |
413d37d1 | 1093 | |
687fcc4a | 1094 | trace_seq_printf(s, "%s: (", trace_event_name(&tp->call)); |
6e9f23d1 | 1095 | |
413d37d1 | 1096 | if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET)) |
85224da0 | 1097 | goto out; |
413d37d1 | 1098 | |
85224da0 | 1099 | trace_seq_puts(s, " <- "); |
413d37d1 MH |
1100 | |
1101 | if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET)) | |
85224da0 | 1102 | goto out; |
413d37d1 | 1103 | |
85224da0 | 1104 | trace_seq_putc(s, ')'); |
413d37d1 | 1105 | |
56de7630 MH |
1106 | if (print_probe_args(s, tp->args, tp->nr_args, |
1107 | (u8 *)&field[1], field) < 0) | |
1108 | goto out; | |
413d37d1 | 1109 | |
85224da0 | 1110 | trace_seq_putc(s, '\n'); |
413d37d1 | 1111 | |
85224da0 SRRH |
1112 | out: |
1113 | return trace_handle_return(s); | |
413d37d1 MH |
1114 | } |
1115 | ||
413d37d1 | 1116 | |
2425bcb9 | 1117 | static int kprobe_event_define_fields(struct trace_event_call *event_call) |
413d37d1 | 1118 | { |
eeb07b06 | 1119 | int ret; |
93ccae7a | 1120 | struct kprobe_trace_entry_head field; |
c31ffb3f | 1121 | struct trace_kprobe *tk = (struct trace_kprobe *)event_call->data; |
413d37d1 | 1122 | |
a703d946 | 1123 | DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0); |
c31ffb3f | 1124 | |
eeb07b06 | 1125 | return traceprobe_define_arg_fields(event_call, sizeof(field), &tk->tp); |
413d37d1 MH |
1126 | } |
1127 | ||
2425bcb9 | 1128 | static int kretprobe_event_define_fields(struct trace_event_call *event_call) |
413d37d1 | 1129 | { |
eeb07b06 | 1130 | int ret; |
93ccae7a | 1131 | struct kretprobe_trace_entry_head field; |
c31ffb3f | 1132 | struct trace_kprobe *tk = (struct trace_kprobe *)event_call->data; |
413d37d1 | 1133 | |
a703d946 MH |
1134 | DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0); |
1135 | DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0); | |
c31ffb3f | 1136 | |
eeb07b06 | 1137 | return traceprobe_define_arg_fields(event_call, sizeof(field), &tk->tp); |
413d37d1 MH |
1138 | } |
1139 | ||
07b139c8 | 1140 | #ifdef CONFIG_PERF_EVENTS |
e08d1c65 MH |
1141 | |
1142 | /* Kprobe profile handler */ | |
9802d865 | 1143 | static int |
c31ffb3f | 1144 | kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs) |
e08d1c65 | 1145 | { |
2425bcb9 | 1146 | struct trace_event_call *call = &tk->tp.call; |
93ccae7a | 1147 | struct kprobe_trace_entry_head *entry; |
1c024eca | 1148 | struct hlist_head *head; |
e09c8614 | 1149 | int size, __size, dsize; |
4ed7c92d | 1150 | int rctx; |
e08d1c65 | 1151 | |
9802d865 | 1152 | if (bpf_prog_array_valid(call)) { |
66665ad2 | 1153 | unsigned long orig_ip = instruction_pointer(regs); |
9802d865 JB |
1154 | int ret; |
1155 | ||
1156 | ret = trace_call_bpf(call, regs); | |
1157 | ||
1158 | /* | |
1159 | * We need to check and see if we modified the pc of the | |
cce188bd MH |
1160 | * pt_regs, and if so return 1 so that we don't do the |
1161 | * single stepping. | |
9802d865 | 1162 | */ |
cce188bd | 1163 | if (orig_ip != instruction_pointer(regs)) |
9802d865 | 1164 | return 1; |
9802d865 JB |
1165 | if (!ret) |
1166 | return 0; | |
1167 | } | |
2541517c | 1168 | |
288e984e ON |
1169 | head = this_cpu_ptr(call->perf_events); |
1170 | if (hlist_empty(head)) | |
9802d865 | 1171 | return 0; |
288e984e | 1172 | |
c31ffb3f NK |
1173 | dsize = __get_data_size(&tk->tp, regs); |
1174 | __size = sizeof(*entry) + tk->tp.size + dsize; | |
74ebb63e MH |
1175 | size = ALIGN(__size + sizeof(u32), sizeof(u64)); |
1176 | size -= sizeof(u32); | |
ce71b9df | 1177 | |
1e1dcd93 | 1178 | entry = perf_trace_buf_alloc(size, NULL, &rctx); |
430ad5a6 | 1179 | if (!entry) |
9802d865 | 1180 | return 0; |
a1a138d0 | 1181 | |
c31ffb3f | 1182 | entry->ip = (unsigned long)tk->rp.kp.addr; |
e09c8614 | 1183 | memset(&entry[1], 0, dsize); |
9178412d | 1184 | store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize); |
1e1dcd93 | 1185 | perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, |
8fd0fbbe | 1186 | head, NULL); |
9802d865 | 1187 | return 0; |
e08d1c65 | 1188 | } |
3da0f180 | 1189 | NOKPROBE_SYMBOL(kprobe_perf_func); |
e08d1c65 MH |
1190 | |
1191 | /* Kretprobe profile handler */ | |
3da0f180 | 1192 | static void |
c31ffb3f | 1193 | kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, |
2b106aab | 1194 | struct pt_regs *regs) |
e08d1c65 | 1195 | { |
2425bcb9 | 1196 | struct trace_event_call *call = &tk->tp.call; |
93ccae7a | 1197 | struct kretprobe_trace_entry_head *entry; |
1c024eca | 1198 | struct hlist_head *head; |
e09c8614 | 1199 | int size, __size, dsize; |
4ed7c92d | 1200 | int rctx; |
e08d1c65 | 1201 | |
e87c6bc3 | 1202 | if (bpf_prog_array_valid(call) && !trace_call_bpf(call, regs)) |
2541517c AS |
1203 | return; |
1204 | ||
288e984e ON |
1205 | head = this_cpu_ptr(call->perf_events); |
1206 | if (hlist_empty(head)) | |
1207 | return; | |
1208 | ||
c31ffb3f NK |
1209 | dsize = __get_data_size(&tk->tp, regs); |
1210 | __size = sizeof(*entry) + tk->tp.size + dsize; | |
74ebb63e MH |
1211 | size = ALIGN(__size + sizeof(u32), sizeof(u64)); |
1212 | size -= sizeof(u32); | |
444a2a3b | 1213 | |
1e1dcd93 | 1214 | entry = perf_trace_buf_alloc(size, NULL, &rctx); |
430ad5a6 | 1215 | if (!entry) |
1e12a4a7 | 1216 | return; |
e08d1c65 | 1217 | |
c31ffb3f | 1218 | entry->func = (unsigned long)tk->rp.kp.addr; |
a1a138d0 | 1219 | entry->ret_ip = (unsigned long)ri->ret_addr; |
9178412d | 1220 | store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize); |
1e1dcd93 | 1221 | perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, |
8fd0fbbe | 1222 | head, NULL); |
e08d1c65 | 1223 | } |
3da0f180 | 1224 | NOKPROBE_SYMBOL(kretprobe_perf_func); |
41bdc4b4 YS |
1225 | |
1226 | int bpf_get_kprobe_info(const struct perf_event *event, u32 *fd_type, | |
1227 | const char **symbol, u64 *probe_offset, | |
1228 | u64 *probe_addr, bool perf_type_tracepoint) | |
1229 | { | |
1230 | const char *pevent = trace_event_name(event->tp_event); | |
1231 | const char *group = event->tp_event->class->system; | |
1232 | struct trace_kprobe *tk; | |
1233 | ||
1234 | if (perf_type_tracepoint) | |
1235 | tk = find_trace_kprobe(pevent, group); | |
1236 | else | |
1237 | tk = event->tp_event->data; | |
1238 | if (!tk) | |
1239 | return -EINVAL; | |
1240 | ||
1241 | *fd_type = trace_kprobe_is_return(tk) ? BPF_FD_TYPE_KRETPROBE | |
1242 | : BPF_FD_TYPE_KPROBE; | |
1243 | if (tk->symbol) { | |
1244 | *symbol = tk->symbol; | |
1245 | *probe_offset = tk->rp.kp.offset; | |
1246 | *probe_addr = 0; | |
1247 | } else { | |
1248 | *symbol = NULL; | |
1249 | *probe_offset = 0; | |
1250 | *probe_addr = (unsigned long)tk->rp.kp.addr; | |
1251 | } | |
1252 | return 0; | |
1253 | } | |
07b139c8 | 1254 | #endif /* CONFIG_PERF_EVENTS */ |
50d78056 | 1255 | |
3fe3d619 ON |
1256 | /* |
1257 | * called by perf_trace_init() or __ftrace_set_clr_event() under event_mutex. | |
1258 | * | |
1259 | * kprobe_trace_self_tests_init() does enable_trace_probe/disable_trace_probe | |
1260 | * lockless, but we can't race with this __init function. | |
1261 | */ | |
2425bcb9 | 1262 | static int kprobe_register(struct trace_event_call *event, |
fbc1963d | 1263 | enum trace_reg type, void *data) |
2239291a | 1264 | { |
c31ffb3f | 1265 | struct trace_kprobe *tk = (struct trace_kprobe *)event->data; |
7f1d2f82 | 1266 | struct trace_event_file *file = data; |
1538f888 | 1267 | |
2239291a SR |
1268 | switch (type) { |
1269 | case TRACE_REG_REGISTER: | |
c31ffb3f | 1270 | return enable_trace_kprobe(tk, file); |
2239291a | 1271 | case TRACE_REG_UNREGISTER: |
c31ffb3f | 1272 | return disable_trace_kprobe(tk, file); |
2239291a SR |
1273 | |
1274 | #ifdef CONFIG_PERF_EVENTS | |
1275 | case TRACE_REG_PERF_REGISTER: | |
c31ffb3f | 1276 | return enable_trace_kprobe(tk, NULL); |
2239291a | 1277 | case TRACE_REG_PERF_UNREGISTER: |
c31ffb3f | 1278 | return disable_trace_kprobe(tk, NULL); |
ceec0b6f JO |
1279 | case TRACE_REG_PERF_OPEN: |
1280 | case TRACE_REG_PERF_CLOSE: | |
489c75c3 JO |
1281 | case TRACE_REG_PERF_ADD: |
1282 | case TRACE_REG_PERF_DEL: | |
ceec0b6f | 1283 | return 0; |
2239291a SR |
1284 | #endif |
1285 | } | |
1286 | return 0; | |
1287 | } | |
50d78056 | 1288 | |
3da0f180 | 1289 | static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs) |
50d78056 | 1290 | { |
c31ffb3f | 1291 | struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp); |
9802d865 | 1292 | int ret = 0; |
e08d1c65 | 1293 | |
a7636d9e | 1294 | raw_cpu_inc(*tk->nhit); |
48182bd2 | 1295 | |
c31ffb3f NK |
1296 | if (tk->tp.flags & TP_FLAG_TRACE) |
1297 | kprobe_trace_func(tk, regs); | |
07b139c8 | 1298 | #ifdef CONFIG_PERF_EVENTS |
c31ffb3f | 1299 | if (tk->tp.flags & TP_FLAG_PROFILE) |
9802d865 | 1300 | ret = kprobe_perf_func(tk, regs); |
07b139c8 | 1301 | #endif |
9802d865 | 1302 | return ret; |
50d78056 | 1303 | } |
3da0f180 | 1304 | NOKPROBE_SYMBOL(kprobe_dispatcher); |
50d78056 | 1305 | |
3da0f180 MH |
1306 | static int |
1307 | kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs) | |
50d78056 | 1308 | { |
c31ffb3f | 1309 | struct trace_kprobe *tk = container_of(ri->rp, struct trace_kprobe, rp); |
50d78056 | 1310 | |
a7636d9e | 1311 | raw_cpu_inc(*tk->nhit); |
48182bd2 | 1312 | |
c31ffb3f NK |
1313 | if (tk->tp.flags & TP_FLAG_TRACE) |
1314 | kretprobe_trace_func(tk, ri, regs); | |
07b139c8 | 1315 | #ifdef CONFIG_PERF_EVENTS |
c31ffb3f NK |
1316 | if (tk->tp.flags & TP_FLAG_PROFILE) |
1317 | kretprobe_perf_func(tk, ri, regs); | |
07b139c8 | 1318 | #endif |
50d78056 MH |
1319 | return 0; /* We don't tweek kernel, so just return 0 */ |
1320 | } | |
3da0f180 | 1321 | NOKPROBE_SYMBOL(kretprobe_dispatcher); |
e08d1c65 | 1322 | |
a9a57763 SR |
1323 | static struct trace_event_functions kretprobe_funcs = { |
1324 | .trace = print_kretprobe_event | |
1325 | }; | |
1326 | ||
1327 | static struct trace_event_functions kprobe_funcs = { | |
1328 | .trace = print_kprobe_event | |
1329 | }; | |
1330 | ||
e12f03d7 SL |
1331 | static inline void init_trace_event_call(struct trace_kprobe *tk, |
1332 | struct trace_event_call *call) | |
413d37d1 | 1333 | { |
ffb9f995 | 1334 | INIT_LIST_HEAD(&call->class->fields); |
c31ffb3f | 1335 | if (trace_kprobe_is_return(tk)) { |
80decc70 | 1336 | call->event.funcs = &kretprobe_funcs; |
2e33af02 | 1337 | call->class->define_fields = kretprobe_event_define_fields; |
413d37d1 | 1338 | } else { |
80decc70 | 1339 | call->event.funcs = &kprobe_funcs; |
2e33af02 | 1340 | call->class->define_fields = kprobe_event_define_fields; |
413d37d1 | 1341 | } |
e12f03d7 SL |
1342 | |
1343 | call->flags = TRACE_EVENT_FL_KPROBE; | |
1344 | call->class->reg = kprobe_register; | |
1345 | call->data = tk; | |
1346 | } | |
1347 | ||
1348 | static int register_kprobe_event(struct trace_kprobe *tk) | |
1349 | { | |
1350 | struct trace_event_call *call = &tk->tp.call; | |
1351 | int ret = 0; | |
1352 | ||
1353 | init_trace_event_call(tk, call); | |
1354 | ||
0a46c854 | 1355 | if (traceprobe_set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) |
a342a028 | 1356 | return -ENOMEM; |
9023c930 | 1357 | ret = register_trace_event(&call->event); |
32c0edae | 1358 | if (!ret) { |
a342a028 | 1359 | kfree(call->print_fmt); |
ff50d991 | 1360 | return -ENODEV; |
a342a028 | 1361 | } |
413d37d1 | 1362 | ret = trace_add_event_call(call); |
ff50d991 | 1363 | if (ret) { |
de7b2973 | 1364 | pr_info("Failed to register kprobe event: %s\n", |
687fcc4a | 1365 | trace_event_name(call)); |
a342a028 | 1366 | kfree(call->print_fmt); |
9023c930 | 1367 | unregister_trace_event(&call->event); |
ff50d991 | 1368 | } |
413d37d1 MH |
1369 | return ret; |
1370 | } | |
1371 | ||
c31ffb3f | 1372 | static int unregister_kprobe_event(struct trace_kprobe *tk) |
413d37d1 | 1373 | { |
40c32592 SRRH |
1374 | int ret; |
1375 | ||
ff50d991 | 1376 | /* tp->event is unregistered in trace_remove_event_call() */ |
c31ffb3f | 1377 | ret = trace_remove_event_call(&tk->tp.call); |
40c32592 | 1378 | if (!ret) |
c31ffb3f | 1379 | kfree(tk->tp.call.print_fmt); |
40c32592 | 1380 | return ret; |
413d37d1 MH |
1381 | } |
1382 | ||
e12f03d7 SL |
1383 | #ifdef CONFIG_PERF_EVENTS |
1384 | /* create a trace_kprobe, but don't add it to global lists */ | |
1385 | struct trace_event_call * | |
1386 | create_local_trace_kprobe(char *func, void *addr, unsigned long offs, | |
1387 | bool is_return) | |
1388 | { | |
1389 | struct trace_kprobe *tk; | |
1390 | int ret; | |
1391 | char *event; | |
1392 | ||
1393 | /* | |
6212dd29 | 1394 | * local trace_kprobes are not added to dyn_event, so they are never |
e12f03d7 SL |
1395 | * searched in find_trace_kprobe(). Therefore, there is no concern of |
1396 | * duplicated name here. | |
1397 | */ | |
1398 | event = func ? func : "DUMMY_EVENT"; | |
1399 | ||
1400 | tk = alloc_trace_kprobe(KPROBE_EVENT_SYSTEM, event, (void *)addr, func, | |
1401 | offs, 0 /* maxactive */, 0 /* nargs */, | |
1402 | is_return); | |
1403 | ||
1404 | if (IS_ERR(tk)) { | |
1405 | pr_info("Failed to allocate trace_probe.(%d)\n", | |
1406 | (int)PTR_ERR(tk)); | |
1407 | return ERR_CAST(tk); | |
1408 | } | |
1409 | ||
1410 | init_trace_event_call(tk, &tk->tp.call); | |
1411 | ||
0a46c854 | 1412 | if (traceprobe_set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) { |
e12f03d7 SL |
1413 | ret = -ENOMEM; |
1414 | goto error; | |
1415 | } | |
1416 | ||
1417 | ret = __register_trace_kprobe(tk); | |
0fc8c358 JO |
1418 | if (ret < 0) { |
1419 | kfree(tk->tp.call.print_fmt); | |
e12f03d7 | 1420 | goto error; |
0fc8c358 | 1421 | } |
e12f03d7 SL |
1422 | |
1423 | return &tk->tp.call; | |
1424 | error: | |
1425 | free_trace_kprobe(tk); | |
1426 | return ERR_PTR(ret); | |
1427 | } | |
1428 | ||
1429 | void destroy_local_trace_kprobe(struct trace_event_call *event_call) | |
1430 | { | |
1431 | struct trace_kprobe *tk; | |
1432 | ||
1433 | tk = container_of(event_call, struct trace_kprobe, tp.call); | |
1434 | ||
1435 | if (trace_probe_is_enabled(&tk->tp)) { | |
1436 | WARN_ON(1); | |
1437 | return; | |
1438 | } | |
1439 | ||
1440 | __unregister_trace_kprobe(tk); | |
0fc8c358 JO |
1441 | |
1442 | kfree(tk->tp.call.print_fmt); | |
e12f03d7 SL |
1443 | free_trace_kprobe(tk); |
1444 | } | |
1445 | #endif /* CONFIG_PERF_EVENTS */ | |
1446 | ||
8434dc93 | 1447 | /* Make a tracefs interface for controlling probe points */ |
413d37d1 MH |
1448 | static __init int init_kprobe_trace(void) |
1449 | { | |
1450 | struct dentry *d_tracer; | |
1451 | struct dentry *entry; | |
6212dd29 MH |
1452 | int ret; |
1453 | ||
1454 | ret = dyn_event_register(&trace_kprobe_ops); | |
1455 | if (ret) | |
1456 | return ret; | |
413d37d1 | 1457 | |
c31ffb3f | 1458 | if (register_module_notifier(&trace_kprobe_module_nb)) |
61424318 MH |
1459 | return -EINVAL; |
1460 | ||
413d37d1 | 1461 | d_tracer = tracing_init_dentry(); |
14a5ae40 | 1462 | if (IS_ERR(d_tracer)) |
413d37d1 MH |
1463 | return 0; |
1464 | ||
8434dc93 | 1465 | entry = tracefs_create_file("kprobe_events", 0644, d_tracer, |
413d37d1 MH |
1466 | NULL, &kprobe_events_ops); |
1467 | ||
cd7e7bd5 | 1468 | /* Event list interface */ |
413d37d1 | 1469 | if (!entry) |
a395d6a7 | 1470 | pr_warn("Could not create tracefs 'kprobe_events' entry\n"); |
cd7e7bd5 MH |
1471 | |
1472 | /* Profile interface */ | |
8434dc93 | 1473 | entry = tracefs_create_file("kprobe_profile", 0444, d_tracer, |
cd7e7bd5 MH |
1474 | NULL, &kprobe_profile_ops); |
1475 | ||
1476 | if (!entry) | |
a395d6a7 | 1477 | pr_warn("Could not create tracefs 'kprobe_profile' entry\n"); |
413d37d1 MH |
1478 | return 0; |
1479 | } | |
1480 | fs_initcall(init_kprobe_trace); | |
1481 | ||
1482 | ||
1483 | #ifdef CONFIG_FTRACE_STARTUP_TEST | |
26a346f2 | 1484 | static __init struct trace_event_file * |
c31ffb3f | 1485 | find_trace_probe_file(struct trace_kprobe *tk, struct trace_array *tr) |
41a7dd42 | 1486 | { |
7f1d2f82 | 1487 | struct trace_event_file *file; |
41a7dd42 MH |
1488 | |
1489 | list_for_each_entry(file, &tr->events, list) | |
c31ffb3f | 1490 | if (file->event_call == &tk->tp.call) |
41a7dd42 MH |
1491 | return file; |
1492 | ||
1493 | return NULL; | |
1494 | } | |
1495 | ||
3fe3d619 | 1496 | /* |
c31ffb3f | 1497 | * Nobody but us can call enable_trace_kprobe/disable_trace_kprobe at this |
3fe3d619 ON |
1498 | * stage, we can do this lockless. |
1499 | */ | |
413d37d1 MH |
1500 | static __init int kprobe_trace_self_tests_init(void) |
1501 | { | |
231e36f4 | 1502 | int ret, warn = 0; |
413d37d1 | 1503 | int (*target)(int, int, int, int, int, int); |
c31ffb3f | 1504 | struct trace_kprobe *tk; |
7f1d2f82 | 1505 | struct trace_event_file *file; |
413d37d1 | 1506 | |
748ec3a2 YY |
1507 | if (tracing_is_disabled()) |
1508 | return -ENODEV; | |
1509 | ||
413d37d1 MH |
1510 | target = kprobe_trace_selftest_target; |
1511 | ||
1512 | pr_info("Testing kprobe tracing: "); | |
1513 | ||
6212dd29 MH |
1514 | ret = trace_run_command("p:testprobe kprobe_trace_selftest_target $stack $stack0 +0($stack)", |
1515 | create_or_delete_trace_kprobe); | |
231e36f4 | 1516 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1517 | pr_warn("error on probing function entry.\n"); |
231e36f4 MH |
1518 | warn++; |
1519 | } else { | |
1520 | /* Enable trace point */ | |
c31ffb3f NK |
1521 | tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM); |
1522 | if (WARN_ON_ONCE(tk == NULL)) { | |
41a7dd42 | 1523 | pr_warn("error on getting new probe.\n"); |
231e36f4 | 1524 | warn++; |
41a7dd42 | 1525 | } else { |
c31ffb3f | 1526 | file = find_trace_probe_file(tk, top_trace_array()); |
41a7dd42 MH |
1527 | if (WARN_ON_ONCE(file == NULL)) { |
1528 | pr_warn("error on getting probe file.\n"); | |
1529 | warn++; | |
1530 | } else | |
c31ffb3f | 1531 | enable_trace_kprobe(tk, file); |
41a7dd42 | 1532 | } |
231e36f4 | 1533 | } |
413d37d1 | 1534 | |
6212dd29 MH |
1535 | ret = trace_run_command("r:testprobe2 kprobe_trace_selftest_target $retval", |
1536 | create_or_delete_trace_kprobe); | |
231e36f4 | 1537 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1538 | pr_warn("error on probing function return.\n"); |
231e36f4 MH |
1539 | warn++; |
1540 | } else { | |
1541 | /* Enable trace point */ | |
c31ffb3f NK |
1542 | tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM); |
1543 | if (WARN_ON_ONCE(tk == NULL)) { | |
41a7dd42 | 1544 | pr_warn("error on getting 2nd new probe.\n"); |
231e36f4 | 1545 | warn++; |
41a7dd42 | 1546 | } else { |
c31ffb3f | 1547 | file = find_trace_probe_file(tk, top_trace_array()); |
41a7dd42 MH |
1548 | if (WARN_ON_ONCE(file == NULL)) { |
1549 | pr_warn("error on getting probe file.\n"); | |
1550 | warn++; | |
1551 | } else | |
c31ffb3f | 1552 | enable_trace_kprobe(tk, file); |
41a7dd42 | 1553 | } |
231e36f4 MH |
1554 | } |
1555 | ||
1556 | if (warn) | |
1557 | goto end; | |
413d37d1 MH |
1558 | |
1559 | ret = target(1, 2, 3, 4, 5, 6); | |
1560 | ||
d4d7ccc8 MN |
1561 | /* |
1562 | * Not expecting an error here, the check is only to prevent the | |
1563 | * optimizer from removing the call to target() as otherwise there | |
1564 | * are no side-effects and the call is never performed. | |
1565 | */ | |
1566 | if (ret != 21) | |
1567 | warn++; | |
1568 | ||
02ca1521 | 1569 | /* Disable trace points before removing it */ |
c31ffb3f NK |
1570 | tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM); |
1571 | if (WARN_ON_ONCE(tk == NULL)) { | |
41a7dd42 | 1572 | pr_warn("error on getting test probe.\n"); |
02ca1521 | 1573 | warn++; |
41a7dd42 | 1574 | } else { |
d4d7ccc8 MN |
1575 | if (trace_kprobe_nhit(tk) != 1) { |
1576 | pr_warn("incorrect number of testprobe hits\n"); | |
1577 | warn++; | |
1578 | } | |
1579 | ||
c31ffb3f | 1580 | file = find_trace_probe_file(tk, top_trace_array()); |
41a7dd42 MH |
1581 | if (WARN_ON_ONCE(file == NULL)) { |
1582 | pr_warn("error on getting probe file.\n"); | |
1583 | warn++; | |
1584 | } else | |
c31ffb3f | 1585 | disable_trace_kprobe(tk, file); |
41a7dd42 | 1586 | } |
02ca1521 | 1587 | |
c31ffb3f NK |
1588 | tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM); |
1589 | if (WARN_ON_ONCE(tk == NULL)) { | |
41a7dd42 | 1590 | pr_warn("error on getting 2nd test probe.\n"); |
02ca1521 | 1591 | warn++; |
41a7dd42 | 1592 | } else { |
d4d7ccc8 MN |
1593 | if (trace_kprobe_nhit(tk) != 1) { |
1594 | pr_warn("incorrect number of testprobe2 hits\n"); | |
1595 | warn++; | |
1596 | } | |
1597 | ||
c31ffb3f | 1598 | file = find_trace_probe_file(tk, top_trace_array()); |
41a7dd42 MH |
1599 | if (WARN_ON_ONCE(file == NULL)) { |
1600 | pr_warn("error on getting probe file.\n"); | |
1601 | warn++; | |
1602 | } else | |
c31ffb3f | 1603 | disable_trace_kprobe(tk, file); |
41a7dd42 | 1604 | } |
02ca1521 | 1605 | |
6212dd29 | 1606 | ret = trace_run_command("-:testprobe", create_or_delete_trace_kprobe); |
231e36f4 | 1607 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1608 | pr_warn("error on deleting a probe.\n"); |
231e36f4 MH |
1609 | warn++; |
1610 | } | |
1611 | ||
6212dd29 | 1612 | ret = trace_run_command("-:testprobe2", 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 | } | |
413d37d1 | 1617 | |
231e36f4 | 1618 | end: |
6212dd29 MH |
1619 | ret = dyn_events_release_all(&trace_kprobe_ops); |
1620 | if (WARN_ON_ONCE(ret)) { | |
1621 | pr_warn("error on cleaning up probes.\n"); | |
1622 | warn++; | |
1623 | } | |
30e7d894 TG |
1624 | /* |
1625 | * Wait for the optimizer work to finish. Otherwise it might fiddle | |
1626 | * with probes in already freed __init text. | |
1627 | */ | |
1628 | wait_for_kprobe_optimizer(); | |
231e36f4 MH |
1629 | if (warn) |
1630 | pr_cont("NG: Some tests are failed. Please check them.\n"); | |
1631 | else | |
1632 | pr_cont("OK\n"); | |
413d37d1 MH |
1633 | return 0; |
1634 | } | |
1635 | ||
1636 | late_initcall(kprobe_trace_self_tests_init); | |
1637 | ||
1638 | #endif |