Commit | Line | Data |
---|---|---|
bcea3f96 | 1 | // SPDX-License-Identifier: GPL-2.0 |
413d37d1 | 2 | /* |
77b44d1b | 3 | * Kprobes-based tracing events |
413d37d1 MH |
4 | * |
5 | * Created by Masami Hiramatsu <mhiramat@redhat.com> | |
6 | * | |
413d37d1 | 7 | */ |
72576341 | 8 | #define pr_fmt(fmt) "trace_kprobe: " fmt |
413d37d1 MH |
9 | |
10 | #include <linux/module.h> | |
11 | #include <linux/uaccess.h> | |
b2d09103 | 12 | #include <linux/rculist.h> |
540adea3 | 13 | #include <linux/error-injection.h> |
413d37d1 | 14 | |
970988e1 MH |
15 | #include <asm/setup.h> /* for COMMAND_LINE_SIZE */ |
16 | ||
6212dd29 | 17 | #include "trace_dynevent.h" |
d899926f | 18 | #include "trace_kprobe_selftest.h" |
8ab83f56 | 19 | #include "trace_probe.h" |
53305928 | 20 | #include "trace_probe_tmpl.h" |
1ff511e3 | 21 | |
8ab83f56 | 22 | #define KPROBE_EVENT_SYSTEM "kprobes" |
696ced4f | 23 | #define KRETPROBE_MAXACTIVE_MAX 4096 |
970988e1 MH |
24 | #define MAX_KPROBE_CMDLINE_SIZE 1024 |
25 | ||
26 | /* Kprobe early definition from command line */ | |
27 | static char kprobe_boot_events_buf[COMMAND_LINE_SIZE] __initdata; | |
b6399cc7 | 28 | static bool kprobe_boot_events_enabled __initdata; |
970988e1 MH |
29 | |
30 | static int __init set_kprobe_boot_events(char *str) | |
31 | { | |
32 | strlcpy(kprobe_boot_events_buf, str, COMMAND_LINE_SIZE); | |
33 | return 0; | |
34 | } | |
35 | __setup("kprobe_event=", set_kprobe_boot_events); | |
e09c8614 | 36 | |
6212dd29 MH |
37 | static int trace_kprobe_create(int argc, const char **argv); |
38 | static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev); | |
39 | static int trace_kprobe_release(struct dyn_event *ev); | |
40 | static bool trace_kprobe_is_busy(struct dyn_event *ev); | |
41 | static bool trace_kprobe_match(const char *system, const char *event, | |
42 | struct dyn_event *ev); | |
43 | ||
44 | static struct dyn_event_operations trace_kprobe_ops = { | |
45 | .create = trace_kprobe_create, | |
46 | .show = trace_kprobe_show, | |
47 | .is_busy = trace_kprobe_is_busy, | |
48 | .free = trace_kprobe_release, | |
49 | .match = trace_kprobe_match, | |
50 | }; | |
51 | ||
cede666e | 52 | /* |
77b44d1b | 53 | * Kprobe event core functions |
413d37d1 | 54 | */ |
c31ffb3f | 55 | struct trace_kprobe { |
6212dd29 | 56 | struct dyn_event devent; |
4a846b44 | 57 | struct kretprobe rp; /* Use rp.kp for kprobe use */ |
a7636d9e | 58 | unsigned long __percpu *nhit; |
413d37d1 | 59 | const char *symbol; /* symbol name */ |
c31ffb3f | 60 | struct trace_probe tp; |
413d37d1 MH |
61 | }; |
62 | ||
6212dd29 MH |
63 | static bool is_trace_kprobe(struct dyn_event *ev) |
64 | { | |
65 | return ev->ops == &trace_kprobe_ops; | |
66 | } | |
67 | ||
68 | static struct trace_kprobe *to_trace_kprobe(struct dyn_event *ev) | |
69 | { | |
70 | return container_of(ev, struct trace_kprobe, devent); | |
71 | } | |
72 | ||
73 | /** | |
74 | * for_each_trace_kprobe - iterate over the trace_kprobe list | |
75 | * @pos: the struct trace_kprobe * for each entry | |
76 | * @dpos: the struct dyn_event * to use as a loop cursor | |
77 | */ | |
78 | #define for_each_trace_kprobe(pos, dpos) \ | |
79 | for_each_dyn_event(dpos) \ | |
80 | if (is_trace_kprobe(dpos) && (pos = to_trace_kprobe(dpos))) | |
81 | ||
c31ffb3f NK |
82 | #define SIZEOF_TRACE_KPROBE(n) \ |
83 | (offsetof(struct trace_kprobe, tp.args) + \ | |
eca0d916 | 84 | (sizeof(struct probe_arg) * (n))) |
a82378d8 | 85 | |
3da0f180 | 86 | static nokprobe_inline bool trace_kprobe_is_return(struct trace_kprobe *tk) |
413d37d1 | 87 | { |
c31ffb3f | 88 | return tk->rp.handler != NULL; |
413d37d1 MH |
89 | } |
90 | ||
3da0f180 | 91 | static nokprobe_inline const char *trace_kprobe_symbol(struct trace_kprobe *tk) |
413d37d1 | 92 | { |
c31ffb3f | 93 | return tk->symbol ? tk->symbol : "unknown"; |
413d37d1 MH |
94 | } |
95 | ||
3da0f180 | 96 | static nokprobe_inline unsigned long trace_kprobe_offset(struct trace_kprobe *tk) |
61424318 | 97 | { |
c31ffb3f | 98 | return tk->rp.kp.offset; |
61424318 MH |
99 | } |
100 | ||
3da0f180 | 101 | static nokprobe_inline bool trace_kprobe_has_gone(struct trace_kprobe *tk) |
61424318 | 102 | { |
c31ffb3f | 103 | return !!(kprobe_gone(&tk->rp.kp)); |
61424318 MH |
104 | } |
105 | ||
3da0f180 | 106 | static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk, |
c31ffb3f | 107 | struct module *mod) |
61424318 MH |
108 | { |
109 | int len = strlen(mod->name); | |
c31ffb3f | 110 | const char *name = trace_kprobe_symbol(tk); |
61424318 MH |
111 | return strncmp(mod->name, name, len) == 0 && name[len] == ':'; |
112 | } | |
113 | ||
59158ec4 | 114 | static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk) |
61424318 | 115 | { |
59158ec4 MH |
116 | char *p; |
117 | bool ret; | |
118 | ||
119 | if (!tk->symbol) | |
120 | return false; | |
121 | p = strchr(tk->symbol, ':'); | |
122 | if (!p) | |
123 | return true; | |
124 | *p = '\0'; | |
125 | mutex_lock(&module_mutex); | |
126 | ret = !!find_module(tk->symbol); | |
127 | mutex_unlock(&module_mutex); | |
128 | *p = ':'; | |
129 | ||
130 | return ret; | |
61424318 MH |
131 | } |
132 | ||
6212dd29 MH |
133 | static bool trace_kprobe_is_busy(struct dyn_event *ev) |
134 | { | |
135 | struct trace_kprobe *tk = to_trace_kprobe(ev); | |
136 | ||
137 | return trace_probe_is_enabled(&tk->tp); | |
138 | } | |
139 | ||
140 | static bool trace_kprobe_match(const char *system, const char *event, | |
141 | struct dyn_event *ev) | |
142 | { | |
143 | struct trace_kprobe *tk = to_trace_kprobe(ev); | |
144 | ||
145 | return strcmp(trace_event_name(&tk->tp.call), event) == 0 && | |
146 | (!system || strcmp(tk->tp.call.class->system, system) == 0); | |
147 | } | |
148 | ||
f18f97ac MN |
149 | static nokprobe_inline unsigned long trace_kprobe_nhit(struct trace_kprobe *tk) |
150 | { | |
151 | unsigned long nhit = 0; | |
152 | int cpu; | |
153 | ||
154 | for_each_possible_cpu(cpu) | |
155 | nhit += *per_cpu_ptr(tk->nhit, cpu); | |
156 | ||
157 | return nhit; | |
158 | } | |
159 | ||
6bc6c77c | 160 | /* Return 0 if it fails to find the symbol address */ |
45408c4f MH |
161 | static nokprobe_inline |
162 | unsigned long trace_kprobe_address(struct trace_kprobe *tk) | |
163 | { | |
164 | unsigned long addr; | |
165 | ||
166 | if (tk->symbol) { | |
167 | addr = (unsigned long) | |
168 | kallsyms_lookup_name(trace_kprobe_symbol(tk)); | |
6bc6c77c MH |
169 | if (addr) |
170 | addr += tk->rp.kp.offset; | |
45408c4f MH |
171 | } else { |
172 | addr = (unsigned long)tk->rp.kp.addr; | |
173 | } | |
174 | return addr; | |
175 | } | |
176 | ||
b4da3340 | 177 | bool trace_kprobe_on_func_entry(struct trace_event_call *call) |
9802d865 JB |
178 | { |
179 | struct trace_kprobe *tk = (struct trace_kprobe *)call->data; | |
b4da3340 MH |
180 | |
181 | return kprobe_on_func_entry(tk->rp.kp.addr, | |
182 | tk->rp.kp.addr ? NULL : tk->rp.kp.symbol_name, | |
183 | tk->rp.kp.addr ? 0 : tk->rp.kp.offset); | |
9802d865 JB |
184 | } |
185 | ||
b4da3340 | 186 | bool trace_kprobe_error_injectable(struct trace_event_call *call) |
9802d865 JB |
187 | { |
188 | struct trace_kprobe *tk = (struct trace_kprobe *)call->data; | |
9802d865 | 189 | |
45408c4f | 190 | return within_error_injection_list(trace_kprobe_address(tk)); |
9802d865 JB |
191 | } |
192 | ||
c31ffb3f NK |
193 | static int register_kprobe_event(struct trace_kprobe *tk); |
194 | static int unregister_kprobe_event(struct trace_kprobe *tk); | |
413d37d1 | 195 | |
50d78056 MH |
196 | static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs); |
197 | static int kretprobe_dispatcher(struct kretprobe_instance *ri, | |
198 | struct pt_regs *regs); | |
199 | ||
455b2899 MH |
200 | static void free_trace_kprobe(struct trace_kprobe *tk) |
201 | { | |
202 | if (tk) { | |
203 | trace_probe_cleanup(&tk->tp); | |
204 | kfree(tk->symbol); | |
205 | free_percpu(tk->nhit); | |
206 | kfree(tk); | |
207 | } | |
208 | } | |
209 | ||
4a846b44 MH |
210 | /* |
211 | * Allocate new trace_probe and initialize it (including kprobes). | |
212 | */ | |
c31ffb3f | 213 | static struct trace_kprobe *alloc_trace_kprobe(const char *group, |
f52487e9 | 214 | const char *event, |
4a846b44 MH |
215 | void *addr, |
216 | const char *symbol, | |
217 | unsigned long offs, | |
696ced4f | 218 | int maxactive, |
3a6b7666 | 219 | int nargs, bool is_return) |
413d37d1 | 220 | { |
c31ffb3f | 221 | struct trace_kprobe *tk; |
6f3cf440 | 222 | int ret = -ENOMEM; |
413d37d1 | 223 | |
c31ffb3f NK |
224 | tk = kzalloc(SIZEOF_TRACE_KPROBE(nargs), GFP_KERNEL); |
225 | if (!tk) | |
6f3cf440 | 226 | return ERR_PTR(ret); |
413d37d1 | 227 | |
a7636d9e MKL |
228 | tk->nhit = alloc_percpu(unsigned long); |
229 | if (!tk->nhit) | |
230 | goto error; | |
231 | ||
413d37d1 | 232 | if (symbol) { |
c31ffb3f NK |
233 | tk->symbol = kstrdup(symbol, GFP_KERNEL); |
234 | if (!tk->symbol) | |
413d37d1 | 235 | goto error; |
c31ffb3f NK |
236 | tk->rp.kp.symbol_name = tk->symbol; |
237 | tk->rp.kp.offset = offs; | |
4a846b44 | 238 | } else |
c31ffb3f | 239 | tk->rp.kp.addr = addr; |
4a846b44 MH |
240 | |
241 | if (is_return) | |
c31ffb3f | 242 | tk->rp.handler = kretprobe_dispatcher; |
4a846b44 | 243 | else |
c31ffb3f | 244 | tk->rp.kp.pre_handler = kprobe_dispatcher; |
4a846b44 | 245 | |
696ced4f AC |
246 | tk->rp.maxactive = maxactive; |
247 | ||
455b2899 MH |
248 | ret = trace_probe_init(&tk->tp, event, group); |
249 | if (ret < 0) | |
f52487e9 MH |
250 | goto error; |
251 | ||
6212dd29 | 252 | dyn_event_init(&tk->devent, &trace_kprobe_ops); |
c31ffb3f | 253 | return tk; |
413d37d1 | 254 | error: |
455b2899 | 255 | free_trace_kprobe(tk); |
6f3cf440 | 256 | return ERR_PTR(ret); |
413d37d1 MH |
257 | } |
258 | ||
c31ffb3f NK |
259 | static struct trace_kprobe *find_trace_kprobe(const char *event, |
260 | const char *group) | |
413d37d1 | 261 | { |
6212dd29 | 262 | struct dyn_event *pos; |
c31ffb3f | 263 | struct trace_kprobe *tk; |
413d37d1 | 264 | |
6212dd29 | 265 | for_each_trace_kprobe(tk, pos) |
687fcc4a | 266 | if (strcmp(trace_event_name(&tk->tp.call), event) == 0 && |
c31ffb3f NK |
267 | strcmp(tk->tp.call.class->system, group) == 0) |
268 | return tk; | |
413d37d1 MH |
269 | return NULL; |
270 | } | |
271 | ||
87107a25 SRV |
272 | static inline int __enable_trace_kprobe(struct trace_kprobe *tk) |
273 | { | |
274 | int ret = 0; | |
275 | ||
276 | if (trace_probe_is_registered(&tk->tp) && !trace_kprobe_has_gone(tk)) { | |
277 | if (trace_kprobe_is_return(tk)) | |
278 | ret = enable_kretprobe(&tk->rp); | |
279 | else | |
280 | ret = enable_kprobe(&tk->rp.kp); | |
281 | } | |
282 | ||
283 | return ret; | |
284 | } | |
285 | ||
41a7dd42 MH |
286 | /* |
287 | * Enable trace_probe | |
288 | * if the file is NULL, enable "perf" handler, or enable "trace" handler. | |
289 | */ | |
290 | static int | |
7f1d2f82 | 291 | enable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file) |
1538f888 | 292 | { |
87107a25 | 293 | struct event_file_link *link; |
1538f888 MH |
294 | int ret = 0; |
295 | ||
41a7dd42 | 296 | if (file) { |
b04d52e3 ON |
297 | link = kmalloc(sizeof(*link), GFP_KERNEL); |
298 | if (!link) { | |
41a7dd42 | 299 | ret = -ENOMEM; |
3fe3d619 | 300 | goto out; |
41a7dd42 | 301 | } |
41a7dd42 | 302 | |
b04d52e3 | 303 | link->file = file; |
c31ffb3f | 304 | list_add_tail_rcu(&link->list, &tk->tp.files); |
41a7dd42 | 305 | |
c31ffb3f | 306 | tk->tp.flags |= TP_FLAG_TRACE; |
87107a25 SRV |
307 | ret = __enable_trace_kprobe(tk); |
308 | if (ret) { | |
309 | list_del_rcu(&link->list); | |
57ea2a34 AS |
310 | kfree(link); |
311 | tk->tp.flags &= ~TP_FLAG_TRACE; | |
57ea2a34 | 312 | } |
87107a25 SRV |
313 | |
314 | } else { | |
315 | tk->tp.flags |= TP_FLAG_PROFILE; | |
316 | ret = __enable_trace_kprobe(tk); | |
317 | if (ret) | |
318 | tk->tp.flags &= ~TP_FLAG_PROFILE; | |
57ea2a34 | 319 | } |
3fe3d619 | 320 | out: |
1538f888 MH |
321 | return ret; |
322 | } | |
323 | ||
41a7dd42 MH |
324 | /* |
325 | * Disable trace_probe | |
326 | * if the file is NULL, disable "perf" handler, or disable "trace" handler. | |
327 | */ | |
328 | static int | |
7f1d2f82 | 329 | disable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file) |
1538f888 | 330 | { |
a232e270 MH |
331 | struct event_file_link *link = NULL; |
332 | int wait = 0; | |
41a7dd42 MH |
333 | int ret = 0; |
334 | ||
41a7dd42 | 335 | if (file) { |
c31ffb3f | 336 | link = find_event_file_link(&tk->tp, file); |
b04d52e3 | 337 | if (!link) { |
41a7dd42 | 338 | ret = -EINVAL; |
3fe3d619 | 339 | goto out; |
41a7dd42 MH |
340 | } |
341 | ||
b04d52e3 | 342 | list_del_rcu(&link->list); |
a232e270 | 343 | wait = 1; |
c31ffb3f | 344 | if (!list_empty(&tk->tp.files)) |
b04d52e3 | 345 | goto out; |
41a7dd42 | 346 | |
c31ffb3f | 347 | tk->tp.flags &= ~TP_FLAG_TRACE; |
41a7dd42 | 348 | } else |
c31ffb3f | 349 | tk->tp.flags &= ~TP_FLAG_PROFILE; |
41a7dd42 | 350 | |
c31ffb3f NK |
351 | if (!trace_probe_is_enabled(&tk->tp) && trace_probe_is_registered(&tk->tp)) { |
352 | if (trace_kprobe_is_return(tk)) | |
353 | disable_kretprobe(&tk->rp); | |
1538f888 | 354 | else |
c31ffb3f | 355 | disable_kprobe(&tk->rp.kp); |
a232e270 | 356 | wait = 1; |
1538f888 | 357 | } |
e12f03d7 SL |
358 | |
359 | /* | |
360 | * if tk is not added to any list, it must be a local trace_kprobe | |
361 | * created with perf_event_open. We don't need to wait for these | |
362 | * trace_kprobes | |
363 | */ | |
6212dd29 | 364 | if (list_empty(&tk->devent.list)) |
e12f03d7 | 365 | wait = 0; |
3fe3d619 | 366 | out: |
a232e270 MH |
367 | if (wait) { |
368 | /* | |
369 | * Synchronize with kprobe_trace_func/kretprobe_trace_func | |
370 | * to ensure disabled (all running handlers are finished). | |
371 | * This is not only for kfree(), but also the caller, | |
372 | * trace_remove_event_call() supposes it for releasing | |
373 | * event_call related objects, which will be accessed in | |
374 | * the kprobe_trace_func/kretprobe_trace_func. | |
375 | */ | |
74401729 | 376 | synchronize_rcu(); |
a232e270 MH |
377 | kfree(link); /* Ignored if link == NULL */ |
378 | } | |
379 | ||
41a7dd42 | 380 | return ret; |
1538f888 MH |
381 | } |
382 | ||
45408c4f MH |
383 | #if defined(CONFIG_KPROBES_ON_FTRACE) && \ |
384 | !defined(CONFIG_KPROBE_EVENTS_ON_NOTRACE) | |
385 | static bool within_notrace_func(struct trace_kprobe *tk) | |
386 | { | |
387 | unsigned long offset, size, addr; | |
388 | ||
389 | addr = trace_kprobe_address(tk); | |
6bc6c77c MH |
390 | if (!addr || !kallsyms_lookup_size_offset(addr, &size, &offset)) |
391 | return false; | |
45408c4f | 392 | |
9161a864 MH |
393 | /* Get the entry address of the target function */ |
394 | addr -= offset; | |
395 | ||
396 | /* | |
397 | * Since ftrace_location_range() does inclusive range check, we need | |
398 | * to subtract 1 byte from the end address. | |
399 | */ | |
400 | return !ftrace_location_range(addr, addr + size - 1); | |
45408c4f MH |
401 | } |
402 | #else | |
403 | #define within_notrace_func(tk) (false) | |
404 | #endif | |
405 | ||
61424318 | 406 | /* Internal register function - just handle k*probes and flags */ |
c31ffb3f | 407 | static int __register_trace_kprobe(struct trace_kprobe *tk) |
413d37d1 | 408 | { |
a6682814 | 409 | int i, ret; |
61424318 | 410 | |
c31ffb3f | 411 | if (trace_probe_is_registered(&tk->tp)) |
61424318 MH |
412 | return -EINVAL; |
413 | ||
45408c4f MH |
414 | if (within_notrace_func(tk)) { |
415 | pr_warn("Could not probe notrace function %s\n", | |
416 | trace_kprobe_symbol(tk)); | |
417 | return -EINVAL; | |
418 | } | |
419 | ||
a6682814 MH |
420 | for (i = 0; i < tk->tp.nr_args; i++) { |
421 | ret = traceprobe_update_arg(&tk->tp.args[i]); | |
422 | if (ret) | |
423 | return ret; | |
424 | } | |
425 | ||
61424318 | 426 | /* Set/clear disabled flag according to tp->flag */ |
c31ffb3f NK |
427 | if (trace_probe_is_enabled(&tk->tp)) |
428 | tk->rp.kp.flags &= ~KPROBE_FLAG_DISABLED; | |
61424318 | 429 | else |
c31ffb3f | 430 | tk->rp.kp.flags |= KPROBE_FLAG_DISABLED; |
61424318 | 431 | |
c31ffb3f NK |
432 | if (trace_kprobe_is_return(tk)) |
433 | ret = register_kretprobe(&tk->rp); | |
413d37d1 | 434 | else |
c31ffb3f | 435 | ret = register_kprobe(&tk->rp.kp); |
61424318 | 436 | |
ab105a4f | 437 | if (ret == 0) |
c31ffb3f | 438 | tk->tp.flags |= TP_FLAG_REGISTERED; |
61424318 MH |
439 | return ret; |
440 | } | |
441 | ||
442 | /* Internal unregister function - just handle k*probes and flags */ | |
c31ffb3f | 443 | static void __unregister_trace_kprobe(struct trace_kprobe *tk) |
61424318 | 444 | { |
c31ffb3f NK |
445 | if (trace_probe_is_registered(&tk->tp)) { |
446 | if (trace_kprobe_is_return(tk)) | |
447 | unregister_kretprobe(&tk->rp); | |
61424318 | 448 | else |
c31ffb3f NK |
449 | unregister_kprobe(&tk->rp.kp); |
450 | tk->tp.flags &= ~TP_FLAG_REGISTERED; | |
61424318 | 451 | /* Cleanup kprobe for reuse */ |
c31ffb3f NK |
452 | if (tk->rp.kp.symbol_name) |
453 | tk->rp.kp.addr = NULL; | |
61424318 MH |
454 | } |
455 | } | |
456 | ||
6212dd29 | 457 | /* Unregister a trace_probe and probe_event */ |
c31ffb3f | 458 | static int unregister_trace_kprobe(struct trace_kprobe *tk) |
61424318 | 459 | { |
02ca1521 | 460 | /* Enabled event can not be unregistered */ |
c31ffb3f | 461 | if (trace_probe_is_enabled(&tk->tp)) |
02ca1521 MH |
462 | return -EBUSY; |
463 | ||
40c32592 | 464 | /* Will fail if probe is being used by ftrace or perf */ |
c31ffb3f | 465 | if (unregister_kprobe_event(tk)) |
40c32592 SRRH |
466 | return -EBUSY; |
467 | ||
c31ffb3f | 468 | __unregister_trace_kprobe(tk); |
6212dd29 | 469 | dyn_event_remove(&tk->devent); |
02ca1521 MH |
470 | |
471 | return 0; | |
413d37d1 MH |
472 | } |
473 | ||
474 | /* Register a trace_probe and probe_event */ | |
c31ffb3f | 475 | static int register_trace_kprobe(struct trace_kprobe *tk) |
413d37d1 | 476 | { |
c31ffb3f | 477 | struct trace_kprobe *old_tk; |
413d37d1 MH |
478 | int ret; |
479 | ||
6212dd29 | 480 | mutex_lock(&event_mutex); |
413d37d1 | 481 | |
61424318 | 482 | /* Delete old (same name) event if exist */ |
687fcc4a | 483 | old_tk = find_trace_kprobe(trace_event_name(&tk->tp.call), |
de7b2973 | 484 | tk->tp.call.class->system); |
c31ffb3f NK |
485 | if (old_tk) { |
486 | ret = unregister_trace_kprobe(old_tk); | |
02ca1521 MH |
487 | if (ret < 0) |
488 | goto end; | |
c31ffb3f | 489 | free_trace_kprobe(old_tk); |
2d5e067e | 490 | } |
61424318 MH |
491 | |
492 | /* Register new event */ | |
c31ffb3f | 493 | ret = register_kprobe_event(tk); |
2d5e067e | 494 | if (ret) { |
a395d6a7 | 495 | pr_warn("Failed to register probe event(%d)\n", ret); |
2d5e067e MH |
496 | goto end; |
497 | } | |
498 | ||
61424318 | 499 | /* Register k*probe */ |
c31ffb3f | 500 | ret = __register_trace_kprobe(tk); |
59158ec4 MH |
501 | if (ret == -ENOENT && !trace_kprobe_module_exist(tk)) { |
502 | pr_warn("This probe might be able to register after target module is loaded. Continue.\n"); | |
503 | ret = 0; | |
504 | } | |
505 | ||
61424318 | 506 | if (ret < 0) |
c31ffb3f | 507 | unregister_kprobe_event(tk); |
61424318 | 508 | else |
6212dd29 | 509 | dyn_event_add(&tk->devent); |
61424318 | 510 | |
413d37d1 | 511 | end: |
6212dd29 | 512 | mutex_unlock(&event_mutex); |
413d37d1 MH |
513 | return ret; |
514 | } | |
515 | ||
61424318 | 516 | /* Module notifier call back, checking event on the module */ |
c31ffb3f | 517 | static int trace_kprobe_module_callback(struct notifier_block *nb, |
61424318 MH |
518 | unsigned long val, void *data) |
519 | { | |
520 | struct module *mod = data; | |
6212dd29 | 521 | struct dyn_event *pos; |
c31ffb3f | 522 | struct trace_kprobe *tk; |
61424318 MH |
523 | int ret; |
524 | ||
525 | if (val != MODULE_STATE_COMING) | |
526 | return NOTIFY_DONE; | |
527 | ||
528 | /* Update probes on coming module */ | |
6212dd29 MH |
529 | mutex_lock(&event_mutex); |
530 | for_each_trace_kprobe(tk, pos) { | |
c31ffb3f | 531 | if (trace_kprobe_within_module(tk, mod)) { |
02ca1521 | 532 | /* Don't need to check busy - this should have gone. */ |
c31ffb3f NK |
533 | __unregister_trace_kprobe(tk); |
534 | ret = __register_trace_kprobe(tk); | |
61424318 | 535 | if (ret) |
a395d6a7 JP |
536 | pr_warn("Failed to re-register probe %s on %s: %d\n", |
537 | trace_event_name(&tk->tp.call), | |
538 | mod->name, ret); | |
61424318 MH |
539 | } |
540 | } | |
6212dd29 | 541 | mutex_unlock(&event_mutex); |
61424318 MH |
542 | |
543 | return NOTIFY_DONE; | |
544 | } | |
545 | ||
c31ffb3f NK |
546 | static struct notifier_block trace_kprobe_module_nb = { |
547 | .notifier_call = trace_kprobe_module_callback, | |
61424318 MH |
548 | .priority = 1 /* Invoked after kprobe module callback */ |
549 | }; | |
550 | ||
fca18a47 NR |
551 | /* Convert certain expected symbols into '_' when generating event names */ |
552 | static inline void sanitize_event_name(char *name) | |
553 | { | |
554 | while (*name++ != '\0') | |
555 | if (*name == ':' || *name == '.') | |
556 | *name = '_'; | |
557 | } | |
558 | ||
6212dd29 | 559 | static int trace_kprobe_create(int argc, const char *argv[]) |
413d37d1 MH |
560 | { |
561 | /* | |
562 | * Argument syntax: | |
696ced4f AC |
563 | * - Add kprobe: |
564 | * p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS] | |
565 | * - Add kretprobe: | |
566 | * r[MAXACTIVE][:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS] | |
413d37d1 | 567 | * Fetch args: |
2e06ff63 MH |
568 | * $retval : fetch return value |
569 | * $stack : fetch stack address | |
570 | * $stackN : fetch Nth of stack (N:0-) | |
35abb67d | 571 | * $comm : fetch current task comm |
413d37d1 MH |
572 | * @ADDR : fetch memory at ADDR (ADDR should be in kernel) |
573 | * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol) | |
574 | * %REG : fetch register REG | |
93ccae7a | 575 | * Dereferencing memory fetch: |
413d37d1 | 576 | * +|-offs(ARG) : fetch memory at ARG +|- offs address. |
eca0d916 MH |
577 | * Alias name of args: |
578 | * NAME=FETCHARG : set NAME as alias of FETCHARG. | |
93ccae7a MH |
579 | * Type of args: |
580 | * FETCHARG:TYPE : use TYPE instead of unsigned long. | |
413d37d1 | 581 | */ |
ab105a4f | 582 | struct trace_kprobe *tk = NULL; |
6212dd29 MH |
583 | int i, len, ret = 0; |
584 | bool is_return = false; | |
585 | char *symbol = NULL, *tmp = NULL; | |
586 | const char *event = NULL, *group = KPROBE_EVENT_SYSTEM; | |
696ced4f | 587 | int maxactive = 0; |
c5d343b6 | 588 | long offset = 0; |
413d37d1 | 589 | void *addr = NULL; |
4a846b44 | 590 | char buf[MAX_EVENT_NAME_LEN]; |
a1303af5 | 591 | unsigned int flags = TPARG_FL_KERNEL; |
413d37d1 | 592 | |
8b05a3a7 AR |
593 | switch (argv[0][0]) { |
594 | case 'r': | |
3a6b7666 | 595 | is_return = true; |
a1303af5 | 596 | flags |= TPARG_FL_RETURN; |
8b05a3a7 AR |
597 | break; |
598 | case 'p': | |
599 | break; | |
600 | default: | |
601 | return -ECANCELED; | |
602 | } | |
603 | if (argc < 2) | |
6212dd29 | 604 | return -ECANCELED; |
413d37d1 | 605 | |
ab105a4f MH |
606 | trace_probe_log_init("trace_kprobe", argc, argv); |
607 | ||
696ced4f | 608 | event = strchr(&argv[0][1], ':'); |
6212dd29 | 609 | if (event) |
696ced4f | 610 | event++; |
6212dd29 | 611 | |
287c038c MH |
612 | if (isdigit(argv[0][1])) { |
613 | if (!is_return) { | |
ab105a4f MH |
614 | trace_probe_log_err(1, MAXACT_NO_KPROBE); |
615 | goto parse_error; | |
287c038c | 616 | } |
6212dd29 MH |
617 | if (event) |
618 | len = event - &argv[0][1] - 1; | |
619 | else | |
620 | len = strlen(&argv[0][1]); | |
ab105a4f MH |
621 | if (len > MAX_EVENT_NAME_LEN - 1) { |
622 | trace_probe_log_err(1, BAD_MAXACT); | |
623 | goto parse_error; | |
624 | } | |
6212dd29 MH |
625 | memcpy(buf, &argv[0][1], len); |
626 | buf[len] = '\0'; | |
627 | ret = kstrtouint(buf, 0, &maxactive); | |
287c038c | 628 | if (ret || !maxactive) { |
ab105a4f MH |
629 | trace_probe_log_err(1, BAD_MAXACT); |
630 | goto parse_error; | |
696ced4f AC |
631 | } |
632 | /* kretprobes instances are iterated over via a list. The | |
633 | * maximum should stay reasonable. | |
634 | */ | |
635 | if (maxactive > KRETPROBE_MAXACTIVE_MAX) { | |
ab105a4f MH |
636 | trace_probe_log_err(1, MAXACT_TOO_BIG); |
637 | goto parse_error; | |
696ced4f AC |
638 | } |
639 | } | |
640 | ||
9e52b325 SD |
641 | /* try to parse an address. if that fails, try to read the |
642 | * input as a symbol. */ | |
643 | if (kstrtoul(argv[1], 0, (unsigned long *)&addr)) { | |
ab105a4f | 644 | trace_probe_log_set_index(1); |
6212dd29 | 645 | /* Check whether uprobe event specified */ |
ab105a4f MH |
646 | if (strchr(argv[1], '/') && strchr(argv[1], ':')) { |
647 | ret = -ECANCELED; | |
648 | goto error; | |
649 | } | |
413d37d1 | 650 | /* a symbol specified */ |
6212dd29 MH |
651 | symbol = kstrdup(argv[1], GFP_KERNEL); |
652 | if (!symbol) | |
653 | return -ENOMEM; | |
413d37d1 | 654 | /* TODO: support .init module functions */ |
8ab83f56 | 655 | ret = traceprobe_split_symbol_offset(symbol, &offset); |
c5d343b6 | 656 | if (ret || offset < 0 || offset > UINT_MAX) { |
ab105a4f MH |
657 | trace_probe_log_err(0, BAD_PROBE_ADDR); |
658 | goto parse_error; | |
e63cc239 | 659 | } |
a1303af5 MH |
660 | if (kprobe_on_func_entry(NULL, symbol, offset)) |
661 | flags |= TPARG_FL_FENTRY; | |
662 | if (offset && is_return && !(flags & TPARG_FL_FENTRY)) { | |
ab105a4f MH |
663 | trace_probe_log_err(0, BAD_RETPROBE); |
664 | goto parse_error; | |
e63cc239 | 665 | } |
413d37d1 MH |
666 | } |
667 | ||
ab105a4f | 668 | trace_probe_log_set_index(0); |
6212dd29 | 669 | if (event) { |
ab105a4f MH |
670 | ret = traceprobe_parse_event_name(&event, &group, buf, |
671 | event - argv[0]); | |
6212dd29 | 672 | if (ret) |
ab105a4f | 673 | goto parse_error; |
6212dd29 | 674 | } else { |
4263565d | 675 | /* Make a new event name */ |
4263565d | 676 | if (symbol) |
6f3cf440 | 677 | snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld", |
4263565d MH |
678 | is_return ? 'r' : 'p', symbol, offset); |
679 | else | |
6f3cf440 | 680 | snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p", |
4263565d | 681 | is_return ? 'r' : 'p', addr); |
fca18a47 | 682 | sanitize_event_name(buf); |
4a846b44 MH |
683 | event = buf; |
684 | } | |
6212dd29 MH |
685 | |
686 | /* setup a probe */ | |
696ced4f | 687 | tk = alloc_trace_kprobe(group, event, addr, symbol, offset, maxactive, |
ab105a4f | 688 | argc - 2, is_return); |
c31ffb3f | 689 | if (IS_ERR(tk)) { |
6212dd29 | 690 | ret = PTR_ERR(tk); |
ab105a4f | 691 | /* This must return -ENOMEM, else there is a bug */ |
a039480e | 692 | WARN_ON_ONCE(ret != -ENOMEM); |
ab105a4f | 693 | goto out; /* We know tk is not allocated */ |
e63cc239 | 694 | } |
ab105a4f | 695 | argc -= 2; argv += 2; |
413d37d1 | 696 | |
413d37d1 | 697 | /* parse arguments */ |
a82378d8 | 698 | for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { |
6212dd29 MH |
699 | tmp = kstrdup(argv[i], GFP_KERNEL); |
700 | if (!tmp) { | |
ba8665d7 | 701 | ret = -ENOMEM; |
413d37d1 MH |
702 | goto error; |
703 | } | |
da34634f | 704 | |
ab105a4f | 705 | trace_probe_log_set_index(i + 2); |
6212dd29 MH |
706 | ret = traceprobe_parse_probe_arg(&tk->tp, i, tmp, flags); |
707 | kfree(tmp); | |
d00bbea9 | 708 | if (ret) |
ab105a4f | 709 | goto error; /* This can be -ENOMEM */ |
413d37d1 | 710 | } |
413d37d1 | 711 | |
f730e0f2 MH |
712 | ret = traceprobe_set_print_fmt(&tk->tp, is_return); |
713 | if (ret < 0) | |
714 | goto error; | |
715 | ||
c31ffb3f | 716 | ret = register_trace_kprobe(tk); |
ab105a4f MH |
717 | if (ret) { |
718 | trace_probe_log_set_index(1); | |
719 | if (ret == -EILSEQ) | |
720 | trace_probe_log_err(0, BAD_INSN_BNDRY); | |
721 | else if (ret == -ENOENT) | |
722 | trace_probe_log_err(0, BAD_PROBE_ADDR); | |
723 | else if (ret != -ENOMEM) | |
724 | trace_probe_log_err(0, FAIL_REG_PROBE); | |
413d37d1 | 725 | goto error; |
ab105a4f MH |
726 | } |
727 | ||
6212dd29 | 728 | out: |
ab105a4f | 729 | trace_probe_log_clear(); |
6212dd29 MH |
730 | kfree(symbol); |
731 | return ret; | |
413d37d1 | 732 | |
ab105a4f MH |
733 | parse_error: |
734 | ret = -EINVAL; | |
413d37d1 | 735 | error: |
c31ffb3f | 736 | free_trace_kprobe(tk); |
6212dd29 | 737 | goto out; |
413d37d1 MH |
738 | } |
739 | ||
6212dd29 | 740 | static int create_or_delete_trace_kprobe(int argc, char **argv) |
413d37d1 | 741 | { |
6212dd29 | 742 | int ret; |
02ca1521 | 743 | |
6212dd29 MH |
744 | if (argv[0][0] == '-') |
745 | return dyn_event_release(argc, argv, &trace_kprobe_ops); | |
413d37d1 | 746 | |
6212dd29 MH |
747 | ret = trace_kprobe_create(argc, (const char **)argv); |
748 | return ret == -ECANCELED ? -EINVAL : ret; | |
413d37d1 MH |
749 | } |
750 | ||
6212dd29 | 751 | static int trace_kprobe_release(struct dyn_event *ev) |
413d37d1 | 752 | { |
6212dd29 MH |
753 | struct trace_kprobe *tk = to_trace_kprobe(ev); |
754 | int ret = unregister_trace_kprobe(tk); | |
413d37d1 | 755 | |
6212dd29 MH |
756 | if (!ret) |
757 | free_trace_kprobe(tk); | |
758 | return ret; | |
413d37d1 MH |
759 | } |
760 | ||
6212dd29 | 761 | static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev) |
413d37d1 | 762 | { |
6212dd29 | 763 | struct trace_kprobe *tk = to_trace_kprobe(ev); |
93ccae7a | 764 | int i; |
413d37d1 | 765 | |
fa6f0cc7 | 766 | seq_putc(m, trace_kprobe_is_return(tk) ? 'r' : 'p'); |
de7b2973 | 767 | seq_printf(m, ":%s/%s", tk->tp.call.class->system, |
687fcc4a | 768 | trace_event_name(&tk->tp.call)); |
413d37d1 | 769 | |
c31ffb3f NK |
770 | if (!tk->symbol) |
771 | seq_printf(m, " 0x%p", tk->rp.kp.addr); | |
772 | else if (tk->rp.kp.offset) | |
773 | seq_printf(m, " %s+%u", trace_kprobe_symbol(tk), | |
774 | tk->rp.kp.offset); | |
413d37d1 | 775 | else |
c31ffb3f | 776 | seq_printf(m, " %s", trace_kprobe_symbol(tk)); |
413d37d1 | 777 | |
c31ffb3f NK |
778 | for (i = 0; i < tk->tp.nr_args; i++) |
779 | seq_printf(m, " %s=%s", tk->tp.args[i].name, tk->tp.args[i].comm); | |
fa6f0cc7 | 780 | seq_putc(m, '\n'); |
93ccae7a | 781 | |
413d37d1 MH |
782 | return 0; |
783 | } | |
784 | ||
6212dd29 MH |
785 | static int probes_seq_show(struct seq_file *m, void *v) |
786 | { | |
787 | struct dyn_event *ev = v; | |
788 | ||
789 | if (!is_trace_kprobe(ev)) | |
790 | return 0; | |
791 | ||
792 | return trace_kprobe_show(m, ev); | |
793 | } | |
794 | ||
413d37d1 | 795 | static const struct seq_operations probes_seq_op = { |
6212dd29 MH |
796 | .start = dyn_event_seq_start, |
797 | .next = dyn_event_seq_next, | |
798 | .stop = dyn_event_seq_stop, | |
413d37d1 MH |
799 | .show = probes_seq_show |
800 | }; | |
801 | ||
802 | static int probes_open(struct inode *inode, struct file *file) | |
803 | { | |
02ca1521 MH |
804 | int ret; |
805 | ||
806 | if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { | |
6212dd29 | 807 | ret = dyn_events_release_all(&trace_kprobe_ops); |
02ca1521 MH |
808 | if (ret < 0) |
809 | return ret; | |
810 | } | |
413d37d1 MH |
811 | |
812 | return seq_open(file, &probes_seq_op); | |
813 | } | |
814 | ||
413d37d1 MH |
815 | static ssize_t probes_write(struct file *file, const char __user *buffer, |
816 | size_t count, loff_t *ppos) | |
817 | { | |
7e465baa | 818 | return trace_parse_run_command(file, buffer, count, ppos, |
6212dd29 | 819 | create_or_delete_trace_kprobe); |
413d37d1 MH |
820 | } |
821 | ||
822 | static const struct file_operations kprobe_events_ops = { | |
823 | .owner = THIS_MODULE, | |
824 | .open = probes_open, | |
825 | .read = seq_read, | |
826 | .llseek = seq_lseek, | |
827 | .release = seq_release, | |
828 | .write = probes_write, | |
829 | }; | |
830 | ||
cd7e7bd5 MH |
831 | /* Probes profiling interfaces */ |
832 | static int probes_profile_seq_show(struct seq_file *m, void *v) | |
833 | { | |
6212dd29 MH |
834 | struct dyn_event *ev = v; |
835 | struct trace_kprobe *tk; | |
cd7e7bd5 | 836 | |
6212dd29 MH |
837 | if (!is_trace_kprobe(ev)) |
838 | return 0; | |
cd7e7bd5 | 839 | |
6212dd29 | 840 | tk = to_trace_kprobe(ev); |
de7b2973 | 841 | seq_printf(m, " %-44s %15lu %15lu\n", |
f18f97ac MN |
842 | trace_event_name(&tk->tp.call), |
843 | trace_kprobe_nhit(tk), | |
c31ffb3f | 844 | tk->rp.kp.nmissed); |
cd7e7bd5 MH |
845 | |
846 | return 0; | |
847 | } | |
848 | ||
849 | static const struct seq_operations profile_seq_op = { | |
6212dd29 MH |
850 | .start = dyn_event_seq_start, |
851 | .next = dyn_event_seq_next, | |
852 | .stop = dyn_event_seq_stop, | |
cd7e7bd5 MH |
853 | .show = probes_profile_seq_show |
854 | }; | |
855 | ||
856 | static int profile_open(struct inode *inode, struct file *file) | |
857 | { | |
858 | return seq_open(file, &profile_seq_op); | |
859 | } | |
860 | ||
861 | static const struct file_operations kprobe_profile_ops = { | |
862 | .owner = THIS_MODULE, | |
863 | .open = profile_open, | |
864 | .read = seq_read, | |
865 | .llseek = seq_lseek, | |
866 | .release = seq_release, | |
867 | }; | |
868 | ||
53305928 MH |
869 | /* Kprobe specific fetch functions */ |
870 | ||
871 | /* Return the length of string -- including null terminal byte */ | |
9178412d MH |
872 | static nokprobe_inline int |
873 | fetch_store_strlen(unsigned long addr) | |
53305928 | 874 | { |
53305928 MH |
875 | int ret, len = 0; |
876 | u8 c; | |
877 | ||
53305928 | 878 | do { |
49ef5f45 | 879 | ret = probe_kernel_read(&c, (u8 *)addr + len, 1); |
53305928 MH |
880 | len++; |
881 | } while (c && ret == 0 && len < MAX_STRING_SIZE); | |
882 | ||
9178412d | 883 | return (ret < 0) ? ret : len; |
53305928 MH |
884 | } |
885 | ||
88903c46 MH |
886 | /* Return the length of string -- including null terminal byte */ |
887 | static nokprobe_inline int | |
888 | fetch_store_strlen_user(unsigned long addr) | |
889 | { | |
890 | const void __user *uaddr = (__force const void __user *)addr; | |
891 | ||
892 | return strnlen_unsafe_user(uaddr, MAX_STRING_SIZE); | |
893 | } | |
894 | ||
53305928 MH |
895 | /* |
896 | * Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max | |
897 | * length and relative data location. | |
898 | */ | |
9178412d MH |
899 | static nokprobe_inline int |
900 | fetch_store_string(unsigned long addr, void *dest, void *base) | |
53305928 | 901 | { |
9178412d | 902 | int maxlen = get_loc_len(*(u32 *)dest); |
88903c46 | 903 | void *__dest; |
53305928 MH |
904 | long ret; |
905 | ||
9178412d MH |
906 | if (unlikely(!maxlen)) |
907 | return -ENOMEM; | |
88903c46 MH |
908 | |
909 | __dest = get_loc_data(dest, base); | |
910 | ||
53305928 MH |
911 | /* |
912 | * Try to get string again, since the string can be changed while | |
913 | * probing. | |
914 | */ | |
88903c46 MH |
915 | ret = strncpy_from_unsafe(__dest, (void *)addr, maxlen); |
916 | if (ret >= 0) | |
917 | *(u32 *)dest = make_data_loc(ret, __dest - base); | |
918 | ||
919 | return ret; | |
920 | } | |
53305928 | 921 | |
88903c46 MH |
922 | /* |
923 | * Fetch a null-terminated string from user. Caller MUST set *(u32 *)buf | |
924 | * with max length and relative data location. | |
925 | */ | |
926 | static nokprobe_inline int | |
927 | fetch_store_string_user(unsigned long addr, void *dest, void *base) | |
928 | { | |
929 | const void __user *uaddr = (__force const void __user *)addr; | |
930 | int maxlen = get_loc_len(*(u32 *)dest); | |
931 | void *__dest; | |
932 | long ret; | |
933 | ||
934 | if (unlikely(!maxlen)) | |
935 | return -ENOMEM; | |
936 | ||
937 | __dest = get_loc_data(dest, base); | |
938 | ||
939 | ret = strncpy_from_unsafe_user(__dest, uaddr, maxlen); | |
9178412d | 940 | if (ret >= 0) |
88903c46 MH |
941 | *(u32 *)dest = make_data_loc(ret, __dest - base); |
942 | ||
9178412d | 943 | return ret; |
53305928 MH |
944 | } |
945 | ||
9b960a38 MH |
946 | static nokprobe_inline int |
947 | probe_mem_read(void *dest, void *src, size_t size) | |
948 | { | |
949 | return probe_kernel_read(dest, src, size); | |
950 | } | |
951 | ||
e65f7ae7 MH |
952 | static nokprobe_inline int |
953 | probe_mem_read_user(void *dest, void *src, size_t size) | |
954 | { | |
539b75b2 MH |
955 | const void __user *uaddr = (__force const void __user *)src; |
956 | ||
957 | return probe_user_read(dest, uaddr, size); | |
e65f7ae7 MH |
958 | } |
959 | ||
53305928 MH |
960 | /* Note that we don't verify it, since the code does not come from user space */ |
961 | static int | |
962 | process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest, | |
9178412d | 963 | void *base) |
53305928 MH |
964 | { |
965 | unsigned long val; | |
53305928 | 966 | |
a6682814 | 967 | retry: |
53305928 MH |
968 | /* 1st stage: get value from context */ |
969 | switch (code->op) { | |
970 | case FETCH_OP_REG: | |
971 | val = regs_get_register(regs, code->param); | |
972 | break; | |
973 | case FETCH_OP_STACK: | |
974 | val = regs_get_kernel_stack_nth(regs, code->param); | |
975 | break; | |
976 | case FETCH_OP_STACKP: | |
977 | val = kernel_stack_pointer(regs); | |
978 | break; | |
979 | case FETCH_OP_RETVAL: | |
980 | val = regs_return_value(regs); | |
981 | break; | |
982 | case FETCH_OP_IMM: | |
983 | val = code->immediate; | |
984 | break; | |
985 | case FETCH_OP_COMM: | |
986 | val = (unsigned long)current->comm; | |
987 | break; | |
a1303af5 MH |
988 | #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API |
989 | case FETCH_OP_ARG: | |
990 | val = regs_get_kernel_argument(regs, code->param); | |
991 | break; | |
992 | #endif | |
a6682814 MH |
993 | case FETCH_NOP_SYMBOL: /* Ignore a place holder */ |
994 | code++; | |
995 | goto retry; | |
53305928 MH |
996 | default: |
997 | return -EILSEQ; | |
998 | } | |
999 | code++; | |
1000 | ||
9b960a38 | 1001 | return process_fetch_insn_bottom(code, val, dest, base); |
53305928 MH |
1002 | } |
1003 | NOKPROBE_SYMBOL(process_fetch_insn) | |
1004 | ||
413d37d1 | 1005 | /* Kprobe handler */ |
3da0f180 | 1006 | static nokprobe_inline void |
c31ffb3f | 1007 | __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs, |
7f1d2f82 | 1008 | struct trace_event_file *trace_file) |
413d37d1 | 1009 | { |
93ccae7a | 1010 | struct kprobe_trace_entry_head *entry; |
413d37d1 | 1011 | struct ring_buffer_event *event; |
8f8ffe24 | 1012 | struct ring_buffer *buffer; |
e09c8614 | 1013 | int size, dsize, pc; |
413d37d1 | 1014 | unsigned long irq_flags; |
2425bcb9 | 1015 | struct trace_event_call *call = &tk->tp.call; |
413d37d1 | 1016 | |
7f1d2f82 | 1017 | WARN_ON(call != trace_file->event_call); |
41a7dd42 | 1018 | |
09a5059a | 1019 | if (trace_trigger_soft_disabled(trace_file)) |
13a1e4ae | 1020 | return; |
b8820084 | 1021 | |
413d37d1 MH |
1022 | local_save_flags(irq_flags); |
1023 | pc = preempt_count(); | |
1024 | ||
c31ffb3f NK |
1025 | dsize = __get_data_size(&tk->tp, regs); |
1026 | size = sizeof(*entry) + tk->tp.size + dsize; | |
413d37d1 | 1027 | |
7f1d2f82 | 1028 | event = trace_event_buffer_lock_reserve(&buffer, trace_file, |
41a7dd42 MH |
1029 | call->event.type, |
1030 | size, irq_flags, pc); | |
413d37d1 | 1031 | if (!event) |
1e12a4a7 | 1032 | return; |
413d37d1 MH |
1033 | |
1034 | entry = ring_buffer_event_data(event); | |
c31ffb3f | 1035 | entry->ip = (unsigned long)tk->rp.kp.addr; |
9178412d | 1036 | store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize); |
413d37d1 | 1037 | |
7f1d2f82 | 1038 | event_trigger_unlock_commit_regs(trace_file, buffer, event, |
13a1e4ae | 1039 | entry, irq_flags, pc, regs); |
413d37d1 MH |
1040 | } |
1041 | ||
3da0f180 | 1042 | static void |
c31ffb3f | 1043 | kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs) |
41a7dd42 | 1044 | { |
b04d52e3 | 1045 | struct event_file_link *link; |
41a7dd42 | 1046 | |
c31ffb3f NK |
1047 | list_for_each_entry_rcu(link, &tk->tp.files, list) |
1048 | __kprobe_trace_func(tk, regs, link->file); | |
41a7dd42 | 1049 | } |
3da0f180 | 1050 | NOKPROBE_SYMBOL(kprobe_trace_func); |
41a7dd42 | 1051 | |
413d37d1 | 1052 | /* Kretprobe handler */ |
3da0f180 | 1053 | static nokprobe_inline void |
c31ffb3f | 1054 | __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, |
41a7dd42 | 1055 | struct pt_regs *regs, |
7f1d2f82 | 1056 | struct trace_event_file *trace_file) |
413d37d1 | 1057 | { |
93ccae7a | 1058 | struct kretprobe_trace_entry_head *entry; |
413d37d1 | 1059 | struct ring_buffer_event *event; |
8f8ffe24 | 1060 | struct ring_buffer *buffer; |
e09c8614 | 1061 | int size, pc, dsize; |
413d37d1 | 1062 | unsigned long irq_flags; |
2425bcb9 | 1063 | struct trace_event_call *call = &tk->tp.call; |
413d37d1 | 1064 | |
7f1d2f82 | 1065 | WARN_ON(call != trace_file->event_call); |
41a7dd42 | 1066 | |
09a5059a | 1067 | if (trace_trigger_soft_disabled(trace_file)) |
13a1e4ae | 1068 | return; |
b8820084 | 1069 | |
413d37d1 MH |
1070 | local_save_flags(irq_flags); |
1071 | pc = preempt_count(); | |
1072 | ||
c31ffb3f NK |
1073 | dsize = __get_data_size(&tk->tp, regs); |
1074 | size = sizeof(*entry) + tk->tp.size + dsize; | |
413d37d1 | 1075 | |
7f1d2f82 | 1076 | event = trace_event_buffer_lock_reserve(&buffer, trace_file, |
41a7dd42 MH |
1077 | call->event.type, |
1078 | size, irq_flags, pc); | |
413d37d1 | 1079 | if (!event) |
1e12a4a7 | 1080 | return; |
413d37d1 MH |
1081 | |
1082 | entry = ring_buffer_event_data(event); | |
c31ffb3f | 1083 | entry->func = (unsigned long)tk->rp.kp.addr; |
413d37d1 | 1084 | entry->ret_ip = (unsigned long)ri->ret_addr; |
9178412d | 1085 | store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize); |
413d37d1 | 1086 | |
7f1d2f82 | 1087 | event_trigger_unlock_commit_regs(trace_file, buffer, event, |
13a1e4ae | 1088 | entry, irq_flags, pc, regs); |
413d37d1 MH |
1089 | } |
1090 | ||
3da0f180 | 1091 | static void |
c31ffb3f | 1092 | kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, |
41a7dd42 MH |
1093 | struct pt_regs *regs) |
1094 | { | |
b04d52e3 | 1095 | struct event_file_link *link; |
41a7dd42 | 1096 | |
c31ffb3f NK |
1097 | list_for_each_entry_rcu(link, &tk->tp.files, list) |
1098 | __kretprobe_trace_func(tk, ri, regs, link->file); | |
41a7dd42 | 1099 | } |
3da0f180 | 1100 | NOKPROBE_SYMBOL(kretprobe_trace_func); |
41a7dd42 | 1101 | |
413d37d1 | 1102 | /* Event entry printers */ |
b62fdd97 | 1103 | static enum print_line_t |
a9a57763 SR |
1104 | print_kprobe_event(struct trace_iterator *iter, int flags, |
1105 | struct trace_event *event) | |
413d37d1 | 1106 | { |
93ccae7a | 1107 | struct kprobe_trace_entry_head *field; |
413d37d1 | 1108 | struct trace_seq *s = &iter->seq; |
eca0d916 | 1109 | struct trace_probe *tp; |
413d37d1 | 1110 | |
93ccae7a | 1111 | field = (struct kprobe_trace_entry_head *)iter->ent; |
80decc70 | 1112 | tp = container_of(event, struct trace_probe, call.event); |
413d37d1 | 1113 | |
687fcc4a | 1114 | trace_seq_printf(s, "%s: (", trace_event_name(&tp->call)); |
6e9f23d1 | 1115 | |
413d37d1 | 1116 | if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET)) |
85224da0 | 1117 | goto out; |
413d37d1 | 1118 | |
85224da0 | 1119 | trace_seq_putc(s, ')'); |
413d37d1 | 1120 | |
56de7630 MH |
1121 | if (print_probe_args(s, tp->args, tp->nr_args, |
1122 | (u8 *)&field[1], field) < 0) | |
1123 | goto out; | |
413d37d1 | 1124 | |
85224da0 SRRH |
1125 | trace_seq_putc(s, '\n'); |
1126 | out: | |
1127 | return trace_handle_return(s); | |
413d37d1 MH |
1128 | } |
1129 | ||
b62fdd97 | 1130 | static enum print_line_t |
a9a57763 SR |
1131 | print_kretprobe_event(struct trace_iterator *iter, int flags, |
1132 | struct trace_event *event) | |
413d37d1 | 1133 | { |
93ccae7a | 1134 | struct kretprobe_trace_entry_head *field; |
413d37d1 | 1135 | struct trace_seq *s = &iter->seq; |
eca0d916 | 1136 | struct trace_probe *tp; |
413d37d1 | 1137 | |
93ccae7a | 1138 | field = (struct kretprobe_trace_entry_head *)iter->ent; |
80decc70 | 1139 | tp = container_of(event, struct trace_probe, call.event); |
413d37d1 | 1140 | |
687fcc4a | 1141 | trace_seq_printf(s, "%s: (", trace_event_name(&tp->call)); |
6e9f23d1 | 1142 | |
413d37d1 | 1143 | if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET)) |
85224da0 | 1144 | goto out; |
413d37d1 | 1145 | |
85224da0 | 1146 | trace_seq_puts(s, " <- "); |
413d37d1 MH |
1147 | |
1148 | if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET)) | |
85224da0 | 1149 | goto out; |
413d37d1 | 1150 | |
85224da0 | 1151 | trace_seq_putc(s, ')'); |
413d37d1 | 1152 | |
56de7630 MH |
1153 | if (print_probe_args(s, tp->args, tp->nr_args, |
1154 | (u8 *)&field[1], field) < 0) | |
1155 | goto out; | |
413d37d1 | 1156 | |
85224da0 | 1157 | trace_seq_putc(s, '\n'); |
413d37d1 | 1158 | |
85224da0 SRRH |
1159 | out: |
1160 | return trace_handle_return(s); | |
413d37d1 MH |
1161 | } |
1162 | ||
413d37d1 | 1163 | |
2425bcb9 | 1164 | static int kprobe_event_define_fields(struct trace_event_call *event_call) |
413d37d1 | 1165 | { |
eeb07b06 | 1166 | int ret; |
93ccae7a | 1167 | struct kprobe_trace_entry_head field; |
c31ffb3f | 1168 | struct trace_kprobe *tk = (struct trace_kprobe *)event_call->data; |
413d37d1 | 1169 | |
a703d946 | 1170 | DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0); |
c31ffb3f | 1171 | |
eeb07b06 | 1172 | return traceprobe_define_arg_fields(event_call, sizeof(field), &tk->tp); |
413d37d1 MH |
1173 | } |
1174 | ||
2425bcb9 | 1175 | static int kretprobe_event_define_fields(struct trace_event_call *event_call) |
413d37d1 | 1176 | { |
eeb07b06 | 1177 | int ret; |
93ccae7a | 1178 | struct kretprobe_trace_entry_head field; |
c31ffb3f | 1179 | struct trace_kprobe *tk = (struct trace_kprobe *)event_call->data; |
413d37d1 | 1180 | |
a703d946 MH |
1181 | DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0); |
1182 | DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0); | |
c31ffb3f | 1183 | |
eeb07b06 | 1184 | return traceprobe_define_arg_fields(event_call, sizeof(field), &tk->tp); |
413d37d1 MH |
1185 | } |
1186 | ||
07b139c8 | 1187 | #ifdef CONFIG_PERF_EVENTS |
e08d1c65 MH |
1188 | |
1189 | /* Kprobe profile handler */ | |
9802d865 | 1190 | static int |
c31ffb3f | 1191 | kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs) |
e08d1c65 | 1192 | { |
2425bcb9 | 1193 | struct trace_event_call *call = &tk->tp.call; |
93ccae7a | 1194 | struct kprobe_trace_entry_head *entry; |
1c024eca | 1195 | struct hlist_head *head; |
e09c8614 | 1196 | int size, __size, dsize; |
4ed7c92d | 1197 | int rctx; |
e08d1c65 | 1198 | |
9802d865 | 1199 | if (bpf_prog_array_valid(call)) { |
66665ad2 | 1200 | unsigned long orig_ip = instruction_pointer(regs); |
9802d865 JB |
1201 | int ret; |
1202 | ||
1203 | ret = trace_call_bpf(call, regs); | |
1204 | ||
1205 | /* | |
1206 | * We need to check and see if we modified the pc of the | |
cce188bd MH |
1207 | * pt_regs, and if so return 1 so that we don't do the |
1208 | * single stepping. | |
9802d865 | 1209 | */ |
cce188bd | 1210 | if (orig_ip != instruction_pointer(regs)) |
9802d865 | 1211 | return 1; |
9802d865 JB |
1212 | if (!ret) |
1213 | return 0; | |
1214 | } | |
2541517c | 1215 | |
288e984e ON |
1216 | head = this_cpu_ptr(call->perf_events); |
1217 | if (hlist_empty(head)) | |
9802d865 | 1218 | return 0; |
288e984e | 1219 | |
c31ffb3f NK |
1220 | dsize = __get_data_size(&tk->tp, regs); |
1221 | __size = sizeof(*entry) + tk->tp.size + dsize; | |
74ebb63e MH |
1222 | size = ALIGN(__size + sizeof(u32), sizeof(u64)); |
1223 | size -= sizeof(u32); | |
ce71b9df | 1224 | |
1e1dcd93 | 1225 | entry = perf_trace_buf_alloc(size, NULL, &rctx); |
430ad5a6 | 1226 | if (!entry) |
9802d865 | 1227 | return 0; |
a1a138d0 | 1228 | |
c31ffb3f | 1229 | entry->ip = (unsigned long)tk->rp.kp.addr; |
e09c8614 | 1230 | memset(&entry[1], 0, dsize); |
9178412d | 1231 | store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize); |
1e1dcd93 | 1232 | perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, |
8fd0fbbe | 1233 | head, NULL); |
9802d865 | 1234 | return 0; |
e08d1c65 | 1235 | } |
3da0f180 | 1236 | NOKPROBE_SYMBOL(kprobe_perf_func); |
e08d1c65 MH |
1237 | |
1238 | /* Kretprobe profile handler */ | |
3da0f180 | 1239 | static void |
c31ffb3f | 1240 | kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, |
2b106aab | 1241 | struct pt_regs *regs) |
e08d1c65 | 1242 | { |
2425bcb9 | 1243 | struct trace_event_call *call = &tk->tp.call; |
93ccae7a | 1244 | struct kretprobe_trace_entry_head *entry; |
1c024eca | 1245 | struct hlist_head *head; |
e09c8614 | 1246 | int size, __size, dsize; |
4ed7c92d | 1247 | int rctx; |
e08d1c65 | 1248 | |
e87c6bc3 | 1249 | if (bpf_prog_array_valid(call) && !trace_call_bpf(call, regs)) |
2541517c AS |
1250 | return; |
1251 | ||
288e984e ON |
1252 | head = this_cpu_ptr(call->perf_events); |
1253 | if (hlist_empty(head)) | |
1254 | return; | |
1255 | ||
c31ffb3f NK |
1256 | dsize = __get_data_size(&tk->tp, regs); |
1257 | __size = sizeof(*entry) + tk->tp.size + dsize; | |
74ebb63e MH |
1258 | size = ALIGN(__size + sizeof(u32), sizeof(u64)); |
1259 | size -= sizeof(u32); | |
444a2a3b | 1260 | |
1e1dcd93 | 1261 | entry = perf_trace_buf_alloc(size, NULL, &rctx); |
430ad5a6 | 1262 | if (!entry) |
1e12a4a7 | 1263 | return; |
e08d1c65 | 1264 | |
c31ffb3f | 1265 | entry->func = (unsigned long)tk->rp.kp.addr; |
a1a138d0 | 1266 | entry->ret_ip = (unsigned long)ri->ret_addr; |
9178412d | 1267 | store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize); |
1e1dcd93 | 1268 | perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, |
8fd0fbbe | 1269 | head, NULL); |
e08d1c65 | 1270 | } |
3da0f180 | 1271 | NOKPROBE_SYMBOL(kretprobe_perf_func); |
41bdc4b4 YS |
1272 | |
1273 | int bpf_get_kprobe_info(const struct perf_event *event, u32 *fd_type, | |
1274 | const char **symbol, u64 *probe_offset, | |
1275 | u64 *probe_addr, bool perf_type_tracepoint) | |
1276 | { | |
1277 | const char *pevent = trace_event_name(event->tp_event); | |
1278 | const char *group = event->tp_event->class->system; | |
1279 | struct trace_kprobe *tk; | |
1280 | ||
1281 | if (perf_type_tracepoint) | |
1282 | tk = find_trace_kprobe(pevent, group); | |
1283 | else | |
1284 | tk = event->tp_event->data; | |
1285 | if (!tk) | |
1286 | return -EINVAL; | |
1287 | ||
1288 | *fd_type = trace_kprobe_is_return(tk) ? BPF_FD_TYPE_KRETPROBE | |
1289 | : BPF_FD_TYPE_KPROBE; | |
1290 | if (tk->symbol) { | |
1291 | *symbol = tk->symbol; | |
1292 | *probe_offset = tk->rp.kp.offset; | |
1293 | *probe_addr = 0; | |
1294 | } else { | |
1295 | *symbol = NULL; | |
1296 | *probe_offset = 0; | |
1297 | *probe_addr = (unsigned long)tk->rp.kp.addr; | |
1298 | } | |
1299 | return 0; | |
1300 | } | |
07b139c8 | 1301 | #endif /* CONFIG_PERF_EVENTS */ |
50d78056 | 1302 | |
3fe3d619 ON |
1303 | /* |
1304 | * called by perf_trace_init() or __ftrace_set_clr_event() under event_mutex. | |
1305 | * | |
1306 | * kprobe_trace_self_tests_init() does enable_trace_probe/disable_trace_probe | |
1307 | * lockless, but we can't race with this __init function. | |
1308 | */ | |
2425bcb9 | 1309 | static int kprobe_register(struct trace_event_call *event, |
fbc1963d | 1310 | enum trace_reg type, void *data) |
2239291a | 1311 | { |
c31ffb3f | 1312 | struct trace_kprobe *tk = (struct trace_kprobe *)event->data; |
7f1d2f82 | 1313 | struct trace_event_file *file = data; |
1538f888 | 1314 | |
2239291a SR |
1315 | switch (type) { |
1316 | case TRACE_REG_REGISTER: | |
c31ffb3f | 1317 | return enable_trace_kprobe(tk, file); |
2239291a | 1318 | case TRACE_REG_UNREGISTER: |
c31ffb3f | 1319 | return disable_trace_kprobe(tk, file); |
2239291a SR |
1320 | |
1321 | #ifdef CONFIG_PERF_EVENTS | |
1322 | case TRACE_REG_PERF_REGISTER: | |
c31ffb3f | 1323 | return enable_trace_kprobe(tk, NULL); |
2239291a | 1324 | case TRACE_REG_PERF_UNREGISTER: |
c31ffb3f | 1325 | return disable_trace_kprobe(tk, NULL); |
ceec0b6f JO |
1326 | case TRACE_REG_PERF_OPEN: |
1327 | case TRACE_REG_PERF_CLOSE: | |
489c75c3 JO |
1328 | case TRACE_REG_PERF_ADD: |
1329 | case TRACE_REG_PERF_DEL: | |
ceec0b6f | 1330 | return 0; |
2239291a SR |
1331 | #endif |
1332 | } | |
1333 | return 0; | |
1334 | } | |
50d78056 | 1335 | |
3da0f180 | 1336 | static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs) |
50d78056 | 1337 | { |
c31ffb3f | 1338 | struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp); |
9802d865 | 1339 | int ret = 0; |
e08d1c65 | 1340 | |
a7636d9e | 1341 | raw_cpu_inc(*tk->nhit); |
48182bd2 | 1342 | |
c31ffb3f NK |
1343 | if (tk->tp.flags & TP_FLAG_TRACE) |
1344 | kprobe_trace_func(tk, regs); | |
07b139c8 | 1345 | #ifdef CONFIG_PERF_EVENTS |
c31ffb3f | 1346 | if (tk->tp.flags & TP_FLAG_PROFILE) |
9802d865 | 1347 | ret = kprobe_perf_func(tk, regs); |
07b139c8 | 1348 | #endif |
9802d865 | 1349 | return ret; |
50d78056 | 1350 | } |
3da0f180 | 1351 | NOKPROBE_SYMBOL(kprobe_dispatcher); |
50d78056 | 1352 | |
3da0f180 MH |
1353 | static int |
1354 | kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs) | |
50d78056 | 1355 | { |
c31ffb3f | 1356 | struct trace_kprobe *tk = container_of(ri->rp, struct trace_kprobe, rp); |
50d78056 | 1357 | |
a7636d9e | 1358 | raw_cpu_inc(*tk->nhit); |
48182bd2 | 1359 | |
c31ffb3f NK |
1360 | if (tk->tp.flags & TP_FLAG_TRACE) |
1361 | kretprobe_trace_func(tk, ri, regs); | |
07b139c8 | 1362 | #ifdef CONFIG_PERF_EVENTS |
c31ffb3f NK |
1363 | if (tk->tp.flags & TP_FLAG_PROFILE) |
1364 | kretprobe_perf_func(tk, ri, regs); | |
07b139c8 | 1365 | #endif |
50d78056 MH |
1366 | return 0; /* We don't tweek kernel, so just return 0 */ |
1367 | } | |
3da0f180 | 1368 | NOKPROBE_SYMBOL(kretprobe_dispatcher); |
e08d1c65 | 1369 | |
a9a57763 SR |
1370 | static struct trace_event_functions kretprobe_funcs = { |
1371 | .trace = print_kretprobe_event | |
1372 | }; | |
1373 | ||
1374 | static struct trace_event_functions kprobe_funcs = { | |
1375 | .trace = print_kprobe_event | |
1376 | }; | |
1377 | ||
e12f03d7 SL |
1378 | static inline void init_trace_event_call(struct trace_kprobe *tk, |
1379 | struct trace_event_call *call) | |
413d37d1 | 1380 | { |
c31ffb3f | 1381 | if (trace_kprobe_is_return(tk)) { |
80decc70 | 1382 | call->event.funcs = &kretprobe_funcs; |
2e33af02 | 1383 | call->class->define_fields = kretprobe_event_define_fields; |
413d37d1 | 1384 | } else { |
80decc70 | 1385 | call->event.funcs = &kprobe_funcs; |
2e33af02 | 1386 | call->class->define_fields = kprobe_event_define_fields; |
413d37d1 | 1387 | } |
e12f03d7 SL |
1388 | |
1389 | call->flags = TRACE_EVENT_FL_KPROBE; | |
1390 | call->class->reg = kprobe_register; | |
1391 | call->data = tk; | |
1392 | } | |
1393 | ||
1394 | static int register_kprobe_event(struct trace_kprobe *tk) | |
1395 | { | |
46e5376d | 1396 | init_trace_event_call(tk, &tk->tp.call); |
f730e0f2 | 1397 | |
46e5376d | 1398 | return trace_probe_register_event_call(&tk->tp); |
413d37d1 MH |
1399 | } |
1400 | ||
c31ffb3f | 1401 | static int unregister_kprobe_event(struct trace_kprobe *tk) |
413d37d1 | 1402 | { |
46e5376d | 1403 | return trace_probe_unregister_event_call(&tk->tp); |
413d37d1 MH |
1404 | } |
1405 | ||
e12f03d7 SL |
1406 | #ifdef CONFIG_PERF_EVENTS |
1407 | /* create a trace_kprobe, but don't add it to global lists */ | |
1408 | struct trace_event_call * | |
1409 | create_local_trace_kprobe(char *func, void *addr, unsigned long offs, | |
1410 | bool is_return) | |
1411 | { | |
1412 | struct trace_kprobe *tk; | |
1413 | int ret; | |
1414 | char *event; | |
1415 | ||
1416 | /* | |
6212dd29 | 1417 | * local trace_kprobes are not added to dyn_event, so they are never |
e12f03d7 SL |
1418 | * searched in find_trace_kprobe(). Therefore, there is no concern of |
1419 | * duplicated name here. | |
1420 | */ | |
1421 | event = func ? func : "DUMMY_EVENT"; | |
1422 | ||
1423 | tk = alloc_trace_kprobe(KPROBE_EVENT_SYSTEM, event, (void *)addr, func, | |
1424 | offs, 0 /* maxactive */, 0 /* nargs */, | |
1425 | is_return); | |
1426 | ||
1427 | if (IS_ERR(tk)) { | |
1428 | pr_info("Failed to allocate trace_probe.(%d)\n", | |
1429 | (int)PTR_ERR(tk)); | |
1430 | return ERR_CAST(tk); | |
1431 | } | |
1432 | ||
1433 | init_trace_event_call(tk, &tk->tp.call); | |
1434 | ||
0a46c854 | 1435 | if (traceprobe_set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) { |
e12f03d7 SL |
1436 | ret = -ENOMEM; |
1437 | goto error; | |
1438 | } | |
1439 | ||
1440 | ret = __register_trace_kprobe(tk); | |
f730e0f2 | 1441 | if (ret < 0) |
e12f03d7 SL |
1442 | goto error; |
1443 | ||
1444 | return &tk->tp.call; | |
1445 | error: | |
1446 | free_trace_kprobe(tk); | |
1447 | return ERR_PTR(ret); | |
1448 | } | |
1449 | ||
1450 | void destroy_local_trace_kprobe(struct trace_event_call *event_call) | |
1451 | { | |
1452 | struct trace_kprobe *tk; | |
1453 | ||
1454 | tk = container_of(event_call, struct trace_kprobe, tp.call); | |
1455 | ||
1456 | if (trace_probe_is_enabled(&tk->tp)) { | |
1457 | WARN_ON(1); | |
1458 | return; | |
1459 | } | |
1460 | ||
1461 | __unregister_trace_kprobe(tk); | |
0fc8c358 | 1462 | |
e12f03d7 SL |
1463 | free_trace_kprobe(tk); |
1464 | } | |
1465 | #endif /* CONFIG_PERF_EVENTS */ | |
1466 | ||
970988e1 MH |
1467 | static __init void enable_boot_kprobe_events(void) |
1468 | { | |
1469 | struct trace_array *tr = top_trace_array(); | |
1470 | struct trace_event_file *file; | |
1471 | struct trace_kprobe *tk; | |
1472 | struct dyn_event *pos; | |
1473 | ||
1474 | mutex_lock(&event_mutex); | |
1475 | for_each_trace_kprobe(tk, pos) { | |
1476 | list_for_each_entry(file, &tr->events, list) | |
1477 | if (file->event_call == &tk->tp.call) | |
1478 | trace_event_enable_disable(file, 1, 0); | |
1479 | } | |
1480 | mutex_unlock(&event_mutex); | |
1481 | } | |
1482 | ||
1483 | static __init void setup_boot_kprobe_events(void) | |
1484 | { | |
1485 | char *p, *cmd = kprobe_boot_events_buf; | |
1486 | int ret; | |
1487 | ||
1488 | strreplace(kprobe_boot_events_buf, ',', ' '); | |
1489 | ||
1490 | while (cmd && *cmd != '\0') { | |
1491 | p = strchr(cmd, ';'); | |
1492 | if (p) | |
1493 | *p++ = '\0'; | |
1494 | ||
1495 | ret = trace_run_command(cmd, create_or_delete_trace_kprobe); | |
1496 | if (ret) | |
1497 | pr_warn("Failed to add event(%d): %s\n", ret, cmd); | |
b6399cc7 SRV |
1498 | else |
1499 | kprobe_boot_events_enabled = true; | |
970988e1 MH |
1500 | |
1501 | cmd = p; | |
1502 | } | |
1503 | ||
1504 | enable_boot_kprobe_events(); | |
1505 | } | |
1506 | ||
8434dc93 | 1507 | /* Make a tracefs interface for controlling probe points */ |
413d37d1 MH |
1508 | static __init int init_kprobe_trace(void) |
1509 | { | |
1510 | struct dentry *d_tracer; | |
1511 | struct dentry *entry; | |
6212dd29 MH |
1512 | int ret; |
1513 | ||
1514 | ret = dyn_event_register(&trace_kprobe_ops); | |
1515 | if (ret) | |
1516 | return ret; | |
413d37d1 | 1517 | |
c31ffb3f | 1518 | if (register_module_notifier(&trace_kprobe_module_nb)) |
61424318 MH |
1519 | return -EINVAL; |
1520 | ||
413d37d1 | 1521 | d_tracer = tracing_init_dentry(); |
14a5ae40 | 1522 | if (IS_ERR(d_tracer)) |
413d37d1 MH |
1523 | return 0; |
1524 | ||
8434dc93 | 1525 | entry = tracefs_create_file("kprobe_events", 0644, d_tracer, |
413d37d1 MH |
1526 | NULL, &kprobe_events_ops); |
1527 | ||
cd7e7bd5 | 1528 | /* Event list interface */ |
413d37d1 | 1529 | if (!entry) |
a395d6a7 | 1530 | pr_warn("Could not create tracefs 'kprobe_events' entry\n"); |
cd7e7bd5 MH |
1531 | |
1532 | /* Profile interface */ | |
8434dc93 | 1533 | entry = tracefs_create_file("kprobe_profile", 0444, d_tracer, |
cd7e7bd5 MH |
1534 | NULL, &kprobe_profile_ops); |
1535 | ||
1536 | if (!entry) | |
a395d6a7 | 1537 | pr_warn("Could not create tracefs 'kprobe_profile' entry\n"); |
970988e1 MH |
1538 | |
1539 | setup_boot_kprobe_events(); | |
1540 | ||
413d37d1 MH |
1541 | return 0; |
1542 | } | |
1543 | fs_initcall(init_kprobe_trace); | |
1544 | ||
1545 | ||
1546 | #ifdef CONFIG_FTRACE_STARTUP_TEST | |
26a346f2 | 1547 | static __init struct trace_event_file * |
c31ffb3f | 1548 | find_trace_probe_file(struct trace_kprobe *tk, struct trace_array *tr) |
41a7dd42 | 1549 | { |
7f1d2f82 | 1550 | struct trace_event_file *file; |
41a7dd42 MH |
1551 | |
1552 | list_for_each_entry(file, &tr->events, list) | |
c31ffb3f | 1553 | if (file->event_call == &tk->tp.call) |
41a7dd42 MH |
1554 | return file; |
1555 | ||
1556 | return NULL; | |
1557 | } | |
1558 | ||
3fe3d619 | 1559 | /* |
c31ffb3f | 1560 | * Nobody but us can call enable_trace_kprobe/disable_trace_kprobe at this |
3fe3d619 ON |
1561 | * stage, we can do this lockless. |
1562 | */ | |
413d37d1 MH |
1563 | static __init int kprobe_trace_self_tests_init(void) |
1564 | { | |
231e36f4 | 1565 | int ret, warn = 0; |
413d37d1 | 1566 | int (*target)(int, int, int, int, int, int); |
c31ffb3f | 1567 | struct trace_kprobe *tk; |
7f1d2f82 | 1568 | struct trace_event_file *file; |
413d37d1 | 1569 | |
748ec3a2 YY |
1570 | if (tracing_is_disabled()) |
1571 | return -ENODEV; | |
1572 | ||
b6399cc7 SRV |
1573 | if (kprobe_boot_events_enabled) { |
1574 | pr_info("Skipping kprobe tests due to kprobe_event on cmdline\n"); | |
1575 | return 0; | |
1576 | } | |
1577 | ||
413d37d1 MH |
1578 | target = kprobe_trace_selftest_target; |
1579 | ||
1580 | pr_info("Testing kprobe tracing: "); | |
1581 | ||
6212dd29 MH |
1582 | ret = trace_run_command("p:testprobe kprobe_trace_selftest_target $stack $stack0 +0($stack)", |
1583 | create_or_delete_trace_kprobe); | |
231e36f4 | 1584 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1585 | pr_warn("error on probing function entry.\n"); |
231e36f4 MH |
1586 | warn++; |
1587 | } else { | |
1588 | /* Enable trace point */ | |
c31ffb3f NK |
1589 | tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM); |
1590 | if (WARN_ON_ONCE(tk == NULL)) { | |
41a7dd42 | 1591 | pr_warn("error on getting new probe.\n"); |
231e36f4 | 1592 | warn++; |
41a7dd42 | 1593 | } else { |
c31ffb3f | 1594 | file = find_trace_probe_file(tk, top_trace_array()); |
41a7dd42 MH |
1595 | if (WARN_ON_ONCE(file == NULL)) { |
1596 | pr_warn("error on getting probe file.\n"); | |
1597 | warn++; | |
1598 | } else | |
c31ffb3f | 1599 | enable_trace_kprobe(tk, file); |
41a7dd42 | 1600 | } |
231e36f4 | 1601 | } |
413d37d1 | 1602 | |
6212dd29 MH |
1603 | ret = trace_run_command("r:testprobe2 kprobe_trace_selftest_target $retval", |
1604 | create_or_delete_trace_kprobe); | |
231e36f4 | 1605 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1606 | pr_warn("error on probing function return.\n"); |
231e36f4 MH |
1607 | warn++; |
1608 | } else { | |
1609 | /* Enable trace point */ | |
c31ffb3f NK |
1610 | tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM); |
1611 | if (WARN_ON_ONCE(tk == NULL)) { | |
41a7dd42 | 1612 | pr_warn("error on getting 2nd new probe.\n"); |
231e36f4 | 1613 | warn++; |
41a7dd42 | 1614 | } else { |
c31ffb3f | 1615 | file = find_trace_probe_file(tk, top_trace_array()); |
41a7dd42 MH |
1616 | if (WARN_ON_ONCE(file == NULL)) { |
1617 | pr_warn("error on getting probe file.\n"); | |
1618 | warn++; | |
1619 | } else | |
c31ffb3f | 1620 | enable_trace_kprobe(tk, file); |
41a7dd42 | 1621 | } |
231e36f4 MH |
1622 | } |
1623 | ||
1624 | if (warn) | |
1625 | goto end; | |
413d37d1 MH |
1626 | |
1627 | ret = target(1, 2, 3, 4, 5, 6); | |
1628 | ||
d4d7ccc8 MN |
1629 | /* |
1630 | * Not expecting an error here, the check is only to prevent the | |
1631 | * optimizer from removing the call to target() as otherwise there | |
1632 | * are no side-effects and the call is never performed. | |
1633 | */ | |
1634 | if (ret != 21) | |
1635 | warn++; | |
1636 | ||
02ca1521 | 1637 | /* Disable trace points before removing it */ |
c31ffb3f NK |
1638 | tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM); |
1639 | if (WARN_ON_ONCE(tk == NULL)) { | |
41a7dd42 | 1640 | pr_warn("error on getting test probe.\n"); |
02ca1521 | 1641 | warn++; |
41a7dd42 | 1642 | } else { |
d4d7ccc8 MN |
1643 | if (trace_kprobe_nhit(tk) != 1) { |
1644 | pr_warn("incorrect number of testprobe hits\n"); | |
1645 | warn++; | |
1646 | } | |
1647 | ||
c31ffb3f | 1648 | file = find_trace_probe_file(tk, top_trace_array()); |
41a7dd42 MH |
1649 | if (WARN_ON_ONCE(file == NULL)) { |
1650 | pr_warn("error on getting probe file.\n"); | |
1651 | warn++; | |
1652 | } else | |
c31ffb3f | 1653 | disable_trace_kprobe(tk, file); |
41a7dd42 | 1654 | } |
02ca1521 | 1655 | |
c31ffb3f NK |
1656 | tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM); |
1657 | if (WARN_ON_ONCE(tk == NULL)) { | |
41a7dd42 | 1658 | pr_warn("error on getting 2nd test probe.\n"); |
02ca1521 | 1659 | warn++; |
41a7dd42 | 1660 | } else { |
d4d7ccc8 MN |
1661 | if (trace_kprobe_nhit(tk) != 1) { |
1662 | pr_warn("incorrect number of testprobe2 hits\n"); | |
1663 | warn++; | |
1664 | } | |
1665 | ||
c31ffb3f | 1666 | file = find_trace_probe_file(tk, top_trace_array()); |
41a7dd42 MH |
1667 | if (WARN_ON_ONCE(file == NULL)) { |
1668 | pr_warn("error on getting probe file.\n"); | |
1669 | warn++; | |
1670 | } else | |
c31ffb3f | 1671 | disable_trace_kprobe(tk, file); |
41a7dd42 | 1672 | } |
02ca1521 | 1673 | |
6212dd29 | 1674 | ret = trace_run_command("-:testprobe", create_or_delete_trace_kprobe); |
231e36f4 | 1675 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1676 | pr_warn("error on deleting a probe.\n"); |
231e36f4 MH |
1677 | warn++; |
1678 | } | |
1679 | ||
6212dd29 | 1680 | ret = trace_run_command("-:testprobe2", create_or_delete_trace_kprobe); |
231e36f4 | 1681 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1682 | pr_warn("error on deleting a probe.\n"); |
231e36f4 MH |
1683 | warn++; |
1684 | } | |
413d37d1 | 1685 | |
231e36f4 | 1686 | end: |
6212dd29 MH |
1687 | ret = dyn_events_release_all(&trace_kprobe_ops); |
1688 | if (WARN_ON_ONCE(ret)) { | |
1689 | pr_warn("error on cleaning up probes.\n"); | |
1690 | warn++; | |
1691 | } | |
30e7d894 TG |
1692 | /* |
1693 | * Wait for the optimizer work to finish. Otherwise it might fiddle | |
1694 | * with probes in already freed __init text. | |
1695 | */ | |
1696 | wait_for_kprobe_optimizer(); | |
231e36f4 MH |
1697 | if (warn) |
1698 | pr_cont("NG: Some tests are failed. Please check them.\n"); | |
1699 | else | |
1700 | pr_cont("OK\n"); | |
413d37d1 MH |
1701 | return 0; |
1702 | } | |
1703 | ||
1704 | late_initcall(kprobe_trace_self_tests_init); | |
1705 | ||
1706 | #endif |