Commit | Line | Data |
---|---|---|
bcea3f96 | 1 | // SPDX-License-Identifier: GPL-2.0 |
413d37d1 | 2 | /* |
77b44d1b | 3 | * Kprobes-based tracing events |
413d37d1 MH |
4 | * |
5 | * Created by Masami Hiramatsu <mhiramat@redhat.com> | |
6 | * | |
413d37d1 | 7 | */ |
72576341 | 8 | #define pr_fmt(fmt) "trace_kprobe: " fmt |
413d37d1 MH |
9 | |
10 | #include <linux/module.h> | |
11 | #include <linux/uaccess.h> | |
b2d09103 | 12 | #include <linux/rculist.h> |
540adea3 | 13 | #include <linux/error-injection.h> |
413d37d1 | 14 | |
970988e1 MH |
15 | #include <asm/setup.h> /* for COMMAND_LINE_SIZE */ |
16 | ||
6212dd29 | 17 | #include "trace_dynevent.h" |
d899926f | 18 | #include "trace_kprobe_selftest.h" |
8ab83f56 | 19 | #include "trace_probe.h" |
53305928 | 20 | #include "trace_probe_tmpl.h" |
1ff511e3 | 21 | |
8ab83f56 | 22 | #define KPROBE_EVENT_SYSTEM "kprobes" |
696ced4f | 23 | #define KRETPROBE_MAXACTIVE_MAX 4096 |
970988e1 MH |
24 | #define MAX_KPROBE_CMDLINE_SIZE 1024 |
25 | ||
26 | /* Kprobe early definition from command line */ | |
27 | static char kprobe_boot_events_buf[COMMAND_LINE_SIZE] __initdata; | |
b6399cc7 | 28 | static bool kprobe_boot_events_enabled __initdata; |
970988e1 MH |
29 | |
30 | static int __init set_kprobe_boot_events(char *str) | |
31 | { | |
32 | strlcpy(kprobe_boot_events_buf, str, COMMAND_LINE_SIZE); | |
33 | return 0; | |
34 | } | |
35 | __setup("kprobe_event=", set_kprobe_boot_events); | |
e09c8614 | 36 | |
6212dd29 MH |
37 | static int trace_kprobe_create(int argc, const char **argv); |
38 | static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev); | |
39 | static int trace_kprobe_release(struct dyn_event *ev); | |
40 | static bool trace_kprobe_is_busy(struct dyn_event *ev); | |
41 | static bool trace_kprobe_match(const char *system, const char *event, | |
30199137 | 42 | int argc, const char **argv, struct dyn_event *ev); |
6212dd29 MH |
43 | |
44 | static struct dyn_event_operations trace_kprobe_ops = { | |
45 | .create = trace_kprobe_create, | |
46 | .show = trace_kprobe_show, | |
47 | .is_busy = trace_kprobe_is_busy, | |
48 | .free = trace_kprobe_release, | |
49 | .match = trace_kprobe_match, | |
50 | }; | |
51 | ||
cede666e | 52 | /* |
77b44d1b | 53 | * Kprobe event core functions |
413d37d1 | 54 | */ |
c31ffb3f | 55 | struct trace_kprobe { |
6212dd29 | 56 | struct dyn_event devent; |
4a846b44 | 57 | struct kretprobe rp; /* Use rp.kp for kprobe use */ |
a7636d9e | 58 | unsigned long __percpu *nhit; |
413d37d1 | 59 | const char *symbol; /* symbol name */ |
c31ffb3f | 60 | struct trace_probe tp; |
413d37d1 MH |
61 | }; |
62 | ||
6212dd29 MH |
63 | static bool is_trace_kprobe(struct dyn_event *ev) |
64 | { | |
65 | return ev->ops == &trace_kprobe_ops; | |
66 | } | |
67 | ||
68 | static struct trace_kprobe *to_trace_kprobe(struct dyn_event *ev) | |
69 | { | |
70 | return container_of(ev, struct trace_kprobe, devent); | |
71 | } | |
72 | ||
73 | /** | |
74 | * for_each_trace_kprobe - iterate over the trace_kprobe list | |
75 | * @pos: the struct trace_kprobe * for each entry | |
76 | * @dpos: the struct dyn_event * to use as a loop cursor | |
77 | */ | |
78 | #define for_each_trace_kprobe(pos, dpos) \ | |
79 | for_each_dyn_event(dpos) \ | |
80 | if (is_trace_kprobe(dpos) && (pos = to_trace_kprobe(dpos))) | |
81 | ||
c31ffb3f NK |
82 | #define SIZEOF_TRACE_KPROBE(n) \ |
83 | (offsetof(struct trace_kprobe, tp.args) + \ | |
eca0d916 | 84 | (sizeof(struct probe_arg) * (n))) |
a82378d8 | 85 | |
3da0f180 | 86 | static nokprobe_inline bool trace_kprobe_is_return(struct trace_kprobe *tk) |
413d37d1 | 87 | { |
c31ffb3f | 88 | return tk->rp.handler != NULL; |
413d37d1 MH |
89 | } |
90 | ||
3da0f180 | 91 | static nokprobe_inline const char *trace_kprobe_symbol(struct trace_kprobe *tk) |
413d37d1 | 92 | { |
c31ffb3f | 93 | return tk->symbol ? tk->symbol : "unknown"; |
413d37d1 MH |
94 | } |
95 | ||
3da0f180 | 96 | static nokprobe_inline unsigned long trace_kprobe_offset(struct trace_kprobe *tk) |
61424318 | 97 | { |
c31ffb3f | 98 | return tk->rp.kp.offset; |
61424318 MH |
99 | } |
100 | ||
3da0f180 | 101 | static nokprobe_inline bool trace_kprobe_has_gone(struct trace_kprobe *tk) |
61424318 | 102 | { |
c31ffb3f | 103 | return !!(kprobe_gone(&tk->rp.kp)); |
61424318 MH |
104 | } |
105 | ||
3da0f180 | 106 | static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk, |
c31ffb3f | 107 | struct module *mod) |
61424318 MH |
108 | { |
109 | int len = strlen(mod->name); | |
c31ffb3f | 110 | const char *name = trace_kprobe_symbol(tk); |
61424318 MH |
111 | return strncmp(mod->name, name, len) == 0 && name[len] == ':'; |
112 | } | |
113 | ||
59158ec4 | 114 | static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk) |
61424318 | 115 | { |
59158ec4 MH |
116 | char *p; |
117 | bool ret; | |
118 | ||
119 | if (!tk->symbol) | |
120 | return false; | |
121 | p = strchr(tk->symbol, ':'); | |
122 | if (!p) | |
123 | return true; | |
124 | *p = '\0'; | |
125 | mutex_lock(&module_mutex); | |
126 | ret = !!find_module(tk->symbol); | |
127 | mutex_unlock(&module_mutex); | |
128 | *p = ':'; | |
129 | ||
130 | return ret; | |
61424318 MH |
131 | } |
132 | ||
6212dd29 MH |
133 | static bool trace_kprobe_is_busy(struct dyn_event *ev) |
134 | { | |
135 | struct trace_kprobe *tk = to_trace_kprobe(ev); | |
136 | ||
137 | return trace_probe_is_enabled(&tk->tp); | |
138 | } | |
139 | ||
eb5bf813 MH |
140 | static bool trace_kprobe_match_command_head(struct trace_kprobe *tk, |
141 | int argc, const char **argv) | |
142 | { | |
143 | char buf[MAX_ARGSTR_LEN + 1]; | |
144 | ||
145 | if (!argc) | |
146 | return true; | |
147 | ||
148 | if (!tk->symbol) | |
149 | snprintf(buf, sizeof(buf), "0x%p", tk->rp.kp.addr); | |
150 | else if (tk->rp.kp.offset) | |
151 | snprintf(buf, sizeof(buf), "%s+%u", | |
152 | trace_kprobe_symbol(tk), tk->rp.kp.offset); | |
153 | else | |
154 | snprintf(buf, sizeof(buf), "%s", trace_kprobe_symbol(tk)); | |
155 | if (strcmp(buf, argv[0])) | |
156 | return false; | |
157 | argc--; argv++; | |
158 | ||
159 | return trace_probe_match_command_args(&tk->tp, argc, argv); | |
160 | } | |
161 | ||
6212dd29 | 162 | static bool trace_kprobe_match(const char *system, const char *event, |
30199137 | 163 | int argc, const char **argv, struct dyn_event *ev) |
6212dd29 MH |
164 | { |
165 | struct trace_kprobe *tk = to_trace_kprobe(ev); | |
166 | ||
b55ce203 | 167 | return strcmp(trace_probe_name(&tk->tp), event) == 0 && |
eb5bf813 MH |
168 | (!system || strcmp(trace_probe_group_name(&tk->tp), system) == 0) && |
169 | trace_kprobe_match_command_head(tk, argc, argv); | |
6212dd29 MH |
170 | } |
171 | ||
f18f97ac MN |
172 | static nokprobe_inline unsigned long trace_kprobe_nhit(struct trace_kprobe *tk) |
173 | { | |
174 | unsigned long nhit = 0; | |
175 | int cpu; | |
176 | ||
177 | for_each_possible_cpu(cpu) | |
178 | nhit += *per_cpu_ptr(tk->nhit, cpu); | |
179 | ||
180 | return nhit; | |
181 | } | |
182 | ||
715fa2fd MH |
183 | static nokprobe_inline bool trace_kprobe_is_registered(struct trace_kprobe *tk) |
184 | { | |
185 | return !(list_empty(&tk->rp.kp.list) && | |
186 | hlist_unhashed(&tk->rp.kp.hlist)); | |
187 | } | |
188 | ||
6bc6c77c | 189 | /* Return 0 if it fails to find the symbol address */ |
45408c4f MH |
190 | static nokprobe_inline |
191 | unsigned long trace_kprobe_address(struct trace_kprobe *tk) | |
192 | { | |
193 | unsigned long addr; | |
194 | ||
195 | if (tk->symbol) { | |
196 | addr = (unsigned long) | |
197 | kallsyms_lookup_name(trace_kprobe_symbol(tk)); | |
6bc6c77c MH |
198 | if (addr) |
199 | addr += tk->rp.kp.offset; | |
45408c4f MH |
200 | } else { |
201 | addr = (unsigned long)tk->rp.kp.addr; | |
202 | } | |
203 | return addr; | |
204 | } | |
205 | ||
60d53e2c MH |
206 | static nokprobe_inline struct trace_kprobe * |
207 | trace_kprobe_primary_from_call(struct trace_event_call *call) | |
208 | { | |
209 | struct trace_probe *tp; | |
210 | ||
211 | tp = trace_probe_primary_from_call(call); | |
212 | if (WARN_ON_ONCE(!tp)) | |
213 | return NULL; | |
214 | ||
215 | return container_of(tp, struct trace_kprobe, tp); | |
216 | } | |
217 | ||
b4da3340 | 218 | bool trace_kprobe_on_func_entry(struct trace_event_call *call) |
9802d865 | 219 | { |
60d53e2c | 220 | struct trace_kprobe *tk = trace_kprobe_primary_from_call(call); |
b4da3340 | 221 | |
60d53e2c | 222 | return tk ? kprobe_on_func_entry(tk->rp.kp.addr, |
b4da3340 | 223 | tk->rp.kp.addr ? NULL : tk->rp.kp.symbol_name, |
60d53e2c | 224 | tk->rp.kp.addr ? 0 : tk->rp.kp.offset) : false; |
9802d865 JB |
225 | } |
226 | ||
b4da3340 | 227 | bool trace_kprobe_error_injectable(struct trace_event_call *call) |
9802d865 | 228 | { |
60d53e2c | 229 | struct trace_kprobe *tk = trace_kprobe_primary_from_call(call); |
9802d865 | 230 | |
60d53e2c MH |
231 | return tk ? within_error_injection_list(trace_kprobe_address(tk)) : |
232 | false; | |
9802d865 JB |
233 | } |
234 | ||
c31ffb3f NK |
235 | static int register_kprobe_event(struct trace_kprobe *tk); |
236 | static int unregister_kprobe_event(struct trace_kprobe *tk); | |
413d37d1 | 237 | |
50d78056 MH |
238 | static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs); |
239 | static int kretprobe_dispatcher(struct kretprobe_instance *ri, | |
240 | struct pt_regs *regs); | |
241 | ||
455b2899 MH |
242 | static void free_trace_kprobe(struct trace_kprobe *tk) |
243 | { | |
244 | if (tk) { | |
245 | trace_probe_cleanup(&tk->tp); | |
246 | kfree(tk->symbol); | |
247 | free_percpu(tk->nhit); | |
248 | kfree(tk); | |
249 | } | |
250 | } | |
251 | ||
4a846b44 MH |
252 | /* |
253 | * Allocate new trace_probe and initialize it (including kprobes). | |
254 | */ | |
c31ffb3f | 255 | static struct trace_kprobe *alloc_trace_kprobe(const char *group, |
f52487e9 | 256 | const char *event, |
4a846b44 MH |
257 | void *addr, |
258 | const char *symbol, | |
259 | unsigned long offs, | |
696ced4f | 260 | int maxactive, |
3a6b7666 | 261 | int nargs, bool is_return) |
413d37d1 | 262 | { |
c31ffb3f | 263 | struct trace_kprobe *tk; |
6f3cf440 | 264 | int ret = -ENOMEM; |
413d37d1 | 265 | |
c31ffb3f NK |
266 | tk = kzalloc(SIZEOF_TRACE_KPROBE(nargs), GFP_KERNEL); |
267 | if (!tk) | |
6f3cf440 | 268 | return ERR_PTR(ret); |
413d37d1 | 269 | |
a7636d9e MKL |
270 | tk->nhit = alloc_percpu(unsigned long); |
271 | if (!tk->nhit) | |
272 | goto error; | |
273 | ||
413d37d1 | 274 | if (symbol) { |
c31ffb3f NK |
275 | tk->symbol = kstrdup(symbol, GFP_KERNEL); |
276 | if (!tk->symbol) | |
413d37d1 | 277 | goto error; |
c31ffb3f NK |
278 | tk->rp.kp.symbol_name = tk->symbol; |
279 | tk->rp.kp.offset = offs; | |
4a846b44 | 280 | } else |
c31ffb3f | 281 | tk->rp.kp.addr = addr; |
4a846b44 MH |
282 | |
283 | if (is_return) | |
c31ffb3f | 284 | tk->rp.handler = kretprobe_dispatcher; |
4a846b44 | 285 | else |
c31ffb3f | 286 | tk->rp.kp.pre_handler = kprobe_dispatcher; |
4a846b44 | 287 | |
696ced4f | 288 | tk->rp.maxactive = maxactive; |
715fa2fd MH |
289 | INIT_HLIST_NODE(&tk->rp.kp.hlist); |
290 | INIT_LIST_HEAD(&tk->rp.kp.list); | |
696ced4f | 291 | |
455b2899 MH |
292 | ret = trace_probe_init(&tk->tp, event, group); |
293 | if (ret < 0) | |
f52487e9 MH |
294 | goto error; |
295 | ||
6212dd29 | 296 | dyn_event_init(&tk->devent, &trace_kprobe_ops); |
c31ffb3f | 297 | return tk; |
413d37d1 | 298 | error: |
455b2899 | 299 | free_trace_kprobe(tk); |
6f3cf440 | 300 | return ERR_PTR(ret); |
413d37d1 MH |
301 | } |
302 | ||
c31ffb3f NK |
303 | static struct trace_kprobe *find_trace_kprobe(const char *event, |
304 | const char *group) | |
413d37d1 | 305 | { |
6212dd29 | 306 | struct dyn_event *pos; |
c31ffb3f | 307 | struct trace_kprobe *tk; |
413d37d1 | 308 | |
6212dd29 | 309 | for_each_trace_kprobe(tk, pos) |
b55ce203 MH |
310 | if (strcmp(trace_probe_name(&tk->tp), event) == 0 && |
311 | strcmp(trace_probe_group_name(&tk->tp), group) == 0) | |
c31ffb3f | 312 | return tk; |
413d37d1 MH |
313 | return NULL; |
314 | } | |
315 | ||
87107a25 SRV |
316 | static inline int __enable_trace_kprobe(struct trace_kprobe *tk) |
317 | { | |
318 | int ret = 0; | |
319 | ||
715fa2fd | 320 | if (trace_kprobe_is_registered(tk) && !trace_kprobe_has_gone(tk)) { |
87107a25 SRV |
321 | if (trace_kprobe_is_return(tk)) |
322 | ret = enable_kretprobe(&tk->rp); | |
323 | else | |
324 | ret = enable_kprobe(&tk->rp.kp); | |
325 | } | |
326 | ||
327 | return ret; | |
328 | } | |
329 | ||
60d53e2c MH |
330 | static void __disable_trace_kprobe(struct trace_probe *tp) |
331 | { | |
332 | struct trace_probe *pos; | |
333 | struct trace_kprobe *tk; | |
334 | ||
335 | list_for_each_entry(pos, trace_probe_probe_list(tp), list) { | |
336 | tk = container_of(pos, struct trace_kprobe, tp); | |
337 | if (!trace_kprobe_is_registered(tk)) | |
338 | continue; | |
339 | if (trace_kprobe_is_return(tk)) | |
340 | disable_kretprobe(&tk->rp); | |
341 | else | |
342 | disable_kprobe(&tk->rp.kp); | |
343 | } | |
344 | } | |
345 | ||
41a7dd42 MH |
346 | /* |
347 | * Enable trace_probe | |
348 | * if the file is NULL, enable "perf" handler, or enable "trace" handler. | |
349 | */ | |
60d53e2c MH |
350 | static int enable_trace_kprobe(struct trace_event_call *call, |
351 | struct trace_event_file *file) | |
1538f888 | 352 | { |
60d53e2c MH |
353 | struct trace_probe *pos, *tp; |
354 | struct trace_kprobe *tk; | |
355 | bool enabled; | |
1538f888 MH |
356 | int ret = 0; |
357 | ||
60d53e2c MH |
358 | tp = trace_probe_primary_from_call(call); |
359 | if (WARN_ON_ONCE(!tp)) | |
360 | return -ENODEV; | |
361 | enabled = trace_probe_is_enabled(tp); | |
362 | ||
363 | /* This also changes "enabled" state */ | |
41a7dd42 | 364 | if (file) { |
60d53e2c | 365 | ret = trace_probe_add_file(tp, file); |
b5f935ee MH |
366 | if (ret) |
367 | return ret; | |
368 | } else | |
60d53e2c | 369 | trace_probe_set_flag(tp, TP_FLAG_PROFILE); |
41a7dd42 | 370 | |
b5f935ee MH |
371 | if (enabled) |
372 | return 0; | |
87107a25 | 373 | |
60d53e2c MH |
374 | enabled = false; |
375 | list_for_each_entry(pos, trace_probe_probe_list(tp), list) { | |
376 | tk = container_of(pos, struct trace_kprobe, tp); | |
377 | if (trace_kprobe_has_gone(tk)) | |
378 | continue; | |
379 | ret = __enable_trace_kprobe(tk); | |
380 | if (ret) { | |
381 | if (enabled) { | |
382 | __disable_trace_kprobe(tp); | |
383 | enabled = false; | |
384 | } | |
385 | break; | |
386 | } | |
387 | enabled = true; | |
388 | } | |
389 | ||
390 | if (!enabled) { | |
391 | /* No probe is enabled. Roll back */ | |
b5f935ee | 392 | if (file) |
60d53e2c | 393 | trace_probe_remove_file(tp, file); |
b5f935ee | 394 | else |
60d53e2c MH |
395 | trace_probe_clear_flag(tp, TP_FLAG_PROFILE); |
396 | if (!ret) | |
397 | /* Since all probes are gone, this is not available */ | |
398 | ret = -EADDRNOTAVAIL; | |
57ea2a34 | 399 | } |
b5f935ee | 400 | |
1538f888 MH |
401 | return ret; |
402 | } | |
403 | ||
41a7dd42 MH |
404 | /* |
405 | * Disable trace_probe | |
406 | * if the file is NULL, disable "perf" handler, or disable "trace" handler. | |
407 | */ | |
60d53e2c MH |
408 | static int disable_trace_kprobe(struct trace_event_call *call, |
409 | struct trace_event_file *file) | |
1538f888 | 410 | { |
60d53e2c MH |
411 | struct trace_probe *tp; |
412 | ||
413 | tp = trace_probe_primary_from_call(call); | |
414 | if (WARN_ON_ONCE(!tp)) | |
415 | return -ENODEV; | |
41a7dd42 | 416 | |
41a7dd42 | 417 | if (file) { |
b5f935ee MH |
418 | if (!trace_probe_get_file_link(tp, file)) |
419 | return -ENOENT; | |
420 | if (!trace_probe_has_single_file(tp)) | |
b04d52e3 | 421 | goto out; |
747774d6 | 422 | trace_probe_clear_flag(tp, TP_FLAG_TRACE); |
41a7dd42 | 423 | } else |
747774d6 | 424 | trace_probe_clear_flag(tp, TP_FLAG_PROFILE); |
41a7dd42 | 425 | |
60d53e2c MH |
426 | if (!trace_probe_is_enabled(tp)) |
427 | __disable_trace_kprobe(tp); | |
e12f03d7 | 428 | |
3fe3d619 | 429 | out: |
b5f935ee | 430 | if (file) |
a232e270 | 431 | /* |
b5f935ee MH |
432 | * Synchronization is done in below function. For perf event, |
433 | * file == NULL and perf_trace_event_unreg() calls | |
434 | * tracepoint_synchronize_unregister() to ensure synchronize | |
435 | * event. We don't need to care about it. | |
a232e270 | 436 | */ |
b5f935ee | 437 | trace_probe_remove_file(tp, file); |
a232e270 | 438 | |
60d53e2c | 439 | return 0; |
1538f888 MH |
440 | } |
441 | ||
45408c4f MH |
442 | #if defined(CONFIG_KPROBES_ON_FTRACE) && \ |
443 | !defined(CONFIG_KPROBE_EVENTS_ON_NOTRACE) | |
444 | static bool within_notrace_func(struct trace_kprobe *tk) | |
445 | { | |
446 | unsigned long offset, size, addr; | |
447 | ||
448 | addr = trace_kprobe_address(tk); | |
6bc6c77c MH |
449 | if (!addr || !kallsyms_lookup_size_offset(addr, &size, &offset)) |
450 | return false; | |
45408c4f | 451 | |
9161a864 MH |
452 | /* Get the entry address of the target function */ |
453 | addr -= offset; | |
454 | ||
455 | /* | |
456 | * Since ftrace_location_range() does inclusive range check, we need | |
457 | * to subtract 1 byte from the end address. | |
458 | */ | |
459 | return !ftrace_location_range(addr, addr + size - 1); | |
45408c4f MH |
460 | } |
461 | #else | |
462 | #define within_notrace_func(tk) (false) | |
463 | #endif | |
464 | ||
61424318 | 465 | /* Internal register function - just handle k*probes and flags */ |
c31ffb3f | 466 | static int __register_trace_kprobe(struct trace_kprobe *tk) |
413d37d1 | 467 | { |
a6682814 | 468 | int i, ret; |
61424318 | 469 | |
715fa2fd | 470 | if (trace_kprobe_is_registered(tk)) |
61424318 MH |
471 | return -EINVAL; |
472 | ||
45408c4f MH |
473 | if (within_notrace_func(tk)) { |
474 | pr_warn("Could not probe notrace function %s\n", | |
475 | trace_kprobe_symbol(tk)); | |
476 | return -EINVAL; | |
477 | } | |
478 | ||
a6682814 MH |
479 | for (i = 0; i < tk->tp.nr_args; i++) { |
480 | ret = traceprobe_update_arg(&tk->tp.args[i]); | |
481 | if (ret) | |
482 | return ret; | |
483 | } | |
484 | ||
61424318 | 485 | /* Set/clear disabled flag according to tp->flag */ |
c31ffb3f NK |
486 | if (trace_probe_is_enabled(&tk->tp)) |
487 | tk->rp.kp.flags &= ~KPROBE_FLAG_DISABLED; | |
61424318 | 488 | else |
c31ffb3f | 489 | tk->rp.kp.flags |= KPROBE_FLAG_DISABLED; |
61424318 | 490 | |
c31ffb3f NK |
491 | if (trace_kprobe_is_return(tk)) |
492 | ret = register_kretprobe(&tk->rp); | |
413d37d1 | 493 | else |
c31ffb3f | 494 | ret = register_kprobe(&tk->rp.kp); |
61424318 | 495 | |
61424318 MH |
496 | return ret; |
497 | } | |
498 | ||
499 | /* Internal unregister function - just handle k*probes and flags */ | |
c31ffb3f | 500 | static void __unregister_trace_kprobe(struct trace_kprobe *tk) |
61424318 | 501 | { |
715fa2fd | 502 | if (trace_kprobe_is_registered(tk)) { |
c31ffb3f NK |
503 | if (trace_kprobe_is_return(tk)) |
504 | unregister_kretprobe(&tk->rp); | |
61424318 | 505 | else |
c31ffb3f | 506 | unregister_kprobe(&tk->rp.kp); |
715fa2fd MH |
507 | /* Cleanup kprobe for reuse and mark it unregistered */ |
508 | INIT_HLIST_NODE(&tk->rp.kp.hlist); | |
509 | INIT_LIST_HEAD(&tk->rp.kp.list); | |
c31ffb3f NK |
510 | if (tk->rp.kp.symbol_name) |
511 | tk->rp.kp.addr = NULL; | |
61424318 MH |
512 | } |
513 | } | |
514 | ||
6212dd29 | 515 | /* Unregister a trace_probe and probe_event */ |
c31ffb3f | 516 | static int unregister_trace_kprobe(struct trace_kprobe *tk) |
61424318 | 517 | { |
ca89bc07 MH |
518 | /* If other probes are on the event, just unregister kprobe */ |
519 | if (trace_probe_has_sibling(&tk->tp)) | |
520 | goto unreg; | |
521 | ||
02ca1521 | 522 | /* Enabled event can not be unregistered */ |
c31ffb3f | 523 | if (trace_probe_is_enabled(&tk->tp)) |
02ca1521 MH |
524 | return -EBUSY; |
525 | ||
40c32592 | 526 | /* Will fail if probe is being used by ftrace or perf */ |
c31ffb3f | 527 | if (unregister_kprobe_event(tk)) |
40c32592 SRRH |
528 | return -EBUSY; |
529 | ||
ca89bc07 | 530 | unreg: |
c31ffb3f | 531 | __unregister_trace_kprobe(tk); |
6212dd29 | 532 | dyn_event_remove(&tk->devent); |
ca89bc07 | 533 | trace_probe_unlink(&tk->tp); |
02ca1521 MH |
534 | |
535 | return 0; | |
413d37d1 MH |
536 | } |
537 | ||
ca89bc07 MH |
538 | static int append_trace_kprobe(struct trace_kprobe *tk, struct trace_kprobe *to) |
539 | { | |
540 | int ret; | |
541 | ||
542 | /* Append to existing event */ | |
543 | ret = trace_probe_append(&tk->tp, &to->tp); | |
544 | if (ret) | |
545 | return ret; | |
546 | ||
547 | /* Register k*probe */ | |
548 | ret = __register_trace_kprobe(tk); | |
549 | if (ret == -ENOENT && !trace_kprobe_module_exist(tk)) { | |
550 | pr_warn("This probe might be able to register after target module is loaded. Continue.\n"); | |
551 | ret = 0; | |
552 | } | |
553 | ||
554 | if (ret) | |
555 | trace_probe_unlink(&tk->tp); | |
556 | else | |
557 | dyn_event_add(&tk->devent); | |
558 | ||
559 | return ret; | |
560 | } | |
561 | ||
413d37d1 | 562 | /* Register a trace_probe and probe_event */ |
c31ffb3f | 563 | static int register_trace_kprobe(struct trace_kprobe *tk) |
413d37d1 | 564 | { |
c31ffb3f | 565 | struct trace_kprobe *old_tk; |
413d37d1 MH |
566 | int ret; |
567 | ||
6212dd29 | 568 | mutex_lock(&event_mutex); |
413d37d1 | 569 | |
b55ce203 MH |
570 | old_tk = find_trace_kprobe(trace_probe_name(&tk->tp), |
571 | trace_probe_group_name(&tk->tp)); | |
c31ffb3f | 572 | if (old_tk) { |
ca89bc07 MH |
573 | if (trace_kprobe_is_return(tk) != trace_kprobe_is_return(old_tk)) { |
574 | trace_probe_log_set_index(0); | |
575 | trace_probe_log_err(0, DIFF_PROBE_TYPE); | |
576 | ret = -EEXIST; | |
577 | } else { | |
578 | ret = trace_probe_compare_arg_type(&tk->tp, &old_tk->tp); | |
579 | if (ret) { | |
580 | /* Note that argument starts index = 2 */ | |
581 | trace_probe_log_set_index(ret + 1); | |
582 | trace_probe_log_err(0, DIFF_ARG_TYPE); | |
583 | ret = -EEXIST; | |
584 | } else | |
585 | ret = append_trace_kprobe(tk, old_tk); | |
586 | } | |
587 | goto end; | |
2d5e067e | 588 | } |
61424318 MH |
589 | |
590 | /* Register new event */ | |
c31ffb3f | 591 | ret = register_kprobe_event(tk); |
2d5e067e | 592 | if (ret) { |
a395d6a7 | 593 | pr_warn("Failed to register probe event(%d)\n", ret); |
2d5e067e MH |
594 | goto end; |
595 | } | |
596 | ||
61424318 | 597 | /* Register k*probe */ |
c31ffb3f | 598 | ret = __register_trace_kprobe(tk); |
59158ec4 MH |
599 | if (ret == -ENOENT && !trace_kprobe_module_exist(tk)) { |
600 | pr_warn("This probe might be able to register after target module is loaded. Continue.\n"); | |
601 | ret = 0; | |
602 | } | |
603 | ||
61424318 | 604 | if (ret < 0) |
c31ffb3f | 605 | unregister_kprobe_event(tk); |
61424318 | 606 | else |
6212dd29 | 607 | dyn_event_add(&tk->devent); |
61424318 | 608 | |
413d37d1 | 609 | end: |
6212dd29 | 610 | mutex_unlock(&event_mutex); |
413d37d1 MH |
611 | return ret; |
612 | } | |
613 | ||
61424318 | 614 | /* Module notifier call back, checking event on the module */ |
c31ffb3f | 615 | static int trace_kprobe_module_callback(struct notifier_block *nb, |
61424318 MH |
616 | unsigned long val, void *data) |
617 | { | |
618 | struct module *mod = data; | |
6212dd29 | 619 | struct dyn_event *pos; |
c31ffb3f | 620 | struct trace_kprobe *tk; |
61424318 MH |
621 | int ret; |
622 | ||
623 | if (val != MODULE_STATE_COMING) | |
624 | return NOTIFY_DONE; | |
625 | ||
626 | /* Update probes on coming module */ | |
6212dd29 MH |
627 | mutex_lock(&event_mutex); |
628 | for_each_trace_kprobe(tk, pos) { | |
c31ffb3f | 629 | if (trace_kprobe_within_module(tk, mod)) { |
02ca1521 | 630 | /* Don't need to check busy - this should have gone. */ |
c31ffb3f NK |
631 | __unregister_trace_kprobe(tk); |
632 | ret = __register_trace_kprobe(tk); | |
61424318 | 633 | if (ret) |
a395d6a7 | 634 | pr_warn("Failed to re-register probe %s on %s: %d\n", |
b55ce203 | 635 | trace_probe_name(&tk->tp), |
a395d6a7 | 636 | mod->name, ret); |
61424318 MH |
637 | } |
638 | } | |
6212dd29 | 639 | mutex_unlock(&event_mutex); |
61424318 MH |
640 | |
641 | return NOTIFY_DONE; | |
642 | } | |
643 | ||
c31ffb3f NK |
644 | static struct notifier_block trace_kprobe_module_nb = { |
645 | .notifier_call = trace_kprobe_module_callback, | |
61424318 MH |
646 | .priority = 1 /* Invoked after kprobe module callback */ |
647 | }; | |
648 | ||
fca18a47 NR |
649 | /* Convert certain expected symbols into '_' when generating event names */ |
650 | static inline void sanitize_event_name(char *name) | |
651 | { | |
652 | while (*name++ != '\0') | |
653 | if (*name == ':' || *name == '.') | |
654 | *name = '_'; | |
655 | } | |
656 | ||
6212dd29 | 657 | static int trace_kprobe_create(int argc, const char *argv[]) |
413d37d1 MH |
658 | { |
659 | /* | |
660 | * Argument syntax: | |
696ced4f AC |
661 | * - Add kprobe: |
662 | * p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS] | |
663 | * - Add kretprobe: | |
664 | * r[MAXACTIVE][:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS] | |
413d37d1 | 665 | * Fetch args: |
2e06ff63 MH |
666 | * $retval : fetch return value |
667 | * $stack : fetch stack address | |
668 | * $stackN : fetch Nth of stack (N:0-) | |
35abb67d | 669 | * $comm : fetch current task comm |
413d37d1 MH |
670 | * @ADDR : fetch memory at ADDR (ADDR should be in kernel) |
671 | * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol) | |
672 | * %REG : fetch register REG | |
93ccae7a | 673 | * Dereferencing memory fetch: |
413d37d1 | 674 | * +|-offs(ARG) : fetch memory at ARG +|- offs address. |
eca0d916 MH |
675 | * Alias name of args: |
676 | * NAME=FETCHARG : set NAME as alias of FETCHARG. | |
93ccae7a MH |
677 | * Type of args: |
678 | * FETCHARG:TYPE : use TYPE instead of unsigned long. | |
413d37d1 | 679 | */ |
ab105a4f | 680 | struct trace_kprobe *tk = NULL; |
6212dd29 MH |
681 | int i, len, ret = 0; |
682 | bool is_return = false; | |
683 | char *symbol = NULL, *tmp = NULL; | |
684 | const char *event = NULL, *group = KPROBE_EVENT_SYSTEM; | |
696ced4f | 685 | int maxactive = 0; |
c5d343b6 | 686 | long offset = 0; |
413d37d1 | 687 | void *addr = NULL; |
4a846b44 | 688 | char buf[MAX_EVENT_NAME_LEN]; |
a1303af5 | 689 | unsigned int flags = TPARG_FL_KERNEL; |
413d37d1 | 690 | |
8b05a3a7 AR |
691 | switch (argv[0][0]) { |
692 | case 'r': | |
3a6b7666 | 693 | is_return = true; |
a1303af5 | 694 | flags |= TPARG_FL_RETURN; |
8b05a3a7 AR |
695 | break; |
696 | case 'p': | |
697 | break; | |
698 | default: | |
699 | return -ECANCELED; | |
700 | } | |
701 | if (argc < 2) | |
6212dd29 | 702 | return -ECANCELED; |
413d37d1 | 703 | |
ab105a4f MH |
704 | trace_probe_log_init("trace_kprobe", argc, argv); |
705 | ||
696ced4f | 706 | event = strchr(&argv[0][1], ':'); |
6212dd29 | 707 | if (event) |
696ced4f | 708 | event++; |
6212dd29 | 709 | |
287c038c MH |
710 | if (isdigit(argv[0][1])) { |
711 | if (!is_return) { | |
ab105a4f MH |
712 | trace_probe_log_err(1, MAXACT_NO_KPROBE); |
713 | goto parse_error; | |
287c038c | 714 | } |
6212dd29 MH |
715 | if (event) |
716 | len = event - &argv[0][1] - 1; | |
717 | else | |
718 | len = strlen(&argv[0][1]); | |
ab105a4f MH |
719 | if (len > MAX_EVENT_NAME_LEN - 1) { |
720 | trace_probe_log_err(1, BAD_MAXACT); | |
721 | goto parse_error; | |
722 | } | |
6212dd29 MH |
723 | memcpy(buf, &argv[0][1], len); |
724 | buf[len] = '\0'; | |
725 | ret = kstrtouint(buf, 0, &maxactive); | |
287c038c | 726 | if (ret || !maxactive) { |
ab105a4f MH |
727 | trace_probe_log_err(1, BAD_MAXACT); |
728 | goto parse_error; | |
696ced4f AC |
729 | } |
730 | /* kretprobes instances are iterated over via a list. The | |
731 | * maximum should stay reasonable. | |
732 | */ | |
733 | if (maxactive > KRETPROBE_MAXACTIVE_MAX) { | |
ab105a4f MH |
734 | trace_probe_log_err(1, MAXACT_TOO_BIG); |
735 | goto parse_error; | |
696ced4f AC |
736 | } |
737 | } | |
738 | ||
9e52b325 SD |
739 | /* try to parse an address. if that fails, try to read the |
740 | * input as a symbol. */ | |
741 | if (kstrtoul(argv[1], 0, (unsigned long *)&addr)) { | |
ab105a4f | 742 | trace_probe_log_set_index(1); |
6212dd29 | 743 | /* Check whether uprobe event specified */ |
ab105a4f MH |
744 | if (strchr(argv[1], '/') && strchr(argv[1], ':')) { |
745 | ret = -ECANCELED; | |
746 | goto error; | |
747 | } | |
413d37d1 | 748 | /* a symbol specified */ |
6212dd29 MH |
749 | symbol = kstrdup(argv[1], GFP_KERNEL); |
750 | if (!symbol) | |
751 | return -ENOMEM; | |
413d37d1 | 752 | /* TODO: support .init module functions */ |
8ab83f56 | 753 | ret = traceprobe_split_symbol_offset(symbol, &offset); |
c5d343b6 | 754 | if (ret || offset < 0 || offset > UINT_MAX) { |
ab105a4f MH |
755 | trace_probe_log_err(0, BAD_PROBE_ADDR); |
756 | goto parse_error; | |
e63cc239 | 757 | } |
a1303af5 MH |
758 | if (kprobe_on_func_entry(NULL, symbol, offset)) |
759 | flags |= TPARG_FL_FENTRY; | |
760 | if (offset && is_return && !(flags & TPARG_FL_FENTRY)) { | |
ab105a4f MH |
761 | trace_probe_log_err(0, BAD_RETPROBE); |
762 | goto parse_error; | |
e63cc239 | 763 | } |
413d37d1 MH |
764 | } |
765 | ||
ab105a4f | 766 | trace_probe_log_set_index(0); |
6212dd29 | 767 | if (event) { |
ab105a4f MH |
768 | ret = traceprobe_parse_event_name(&event, &group, buf, |
769 | event - argv[0]); | |
6212dd29 | 770 | if (ret) |
ab105a4f | 771 | goto parse_error; |
6212dd29 | 772 | } else { |
4263565d | 773 | /* Make a new event name */ |
4263565d | 774 | if (symbol) |
6f3cf440 | 775 | snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld", |
4263565d MH |
776 | is_return ? 'r' : 'p', symbol, offset); |
777 | else | |
6f3cf440 | 778 | snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p", |
4263565d | 779 | is_return ? 'r' : 'p', addr); |
fca18a47 | 780 | sanitize_event_name(buf); |
4a846b44 MH |
781 | event = buf; |
782 | } | |
6212dd29 MH |
783 | |
784 | /* setup a probe */ | |
696ced4f | 785 | tk = alloc_trace_kprobe(group, event, addr, symbol, offset, maxactive, |
ab105a4f | 786 | argc - 2, is_return); |
c31ffb3f | 787 | if (IS_ERR(tk)) { |
6212dd29 | 788 | ret = PTR_ERR(tk); |
ab105a4f | 789 | /* This must return -ENOMEM, else there is a bug */ |
a039480e | 790 | WARN_ON_ONCE(ret != -ENOMEM); |
ab105a4f | 791 | goto out; /* We know tk is not allocated */ |
e63cc239 | 792 | } |
ab105a4f | 793 | argc -= 2; argv += 2; |
413d37d1 | 794 | |
413d37d1 | 795 | /* parse arguments */ |
a82378d8 | 796 | for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { |
6212dd29 MH |
797 | tmp = kstrdup(argv[i], GFP_KERNEL); |
798 | if (!tmp) { | |
ba8665d7 | 799 | ret = -ENOMEM; |
413d37d1 MH |
800 | goto error; |
801 | } | |
da34634f | 802 | |
ab105a4f | 803 | trace_probe_log_set_index(i + 2); |
6212dd29 MH |
804 | ret = traceprobe_parse_probe_arg(&tk->tp, i, tmp, flags); |
805 | kfree(tmp); | |
d00bbea9 | 806 | if (ret) |
ab105a4f | 807 | goto error; /* This can be -ENOMEM */ |
413d37d1 | 808 | } |
413d37d1 | 809 | |
f730e0f2 MH |
810 | ret = traceprobe_set_print_fmt(&tk->tp, is_return); |
811 | if (ret < 0) | |
812 | goto error; | |
813 | ||
c31ffb3f | 814 | ret = register_trace_kprobe(tk); |
ab105a4f MH |
815 | if (ret) { |
816 | trace_probe_log_set_index(1); | |
817 | if (ret == -EILSEQ) | |
818 | trace_probe_log_err(0, BAD_INSN_BNDRY); | |
819 | else if (ret == -ENOENT) | |
820 | trace_probe_log_err(0, BAD_PROBE_ADDR); | |
ca89bc07 | 821 | else if (ret != -ENOMEM && ret != -EEXIST) |
ab105a4f | 822 | trace_probe_log_err(0, FAIL_REG_PROBE); |
413d37d1 | 823 | goto error; |
ab105a4f MH |
824 | } |
825 | ||
6212dd29 | 826 | out: |
ab105a4f | 827 | trace_probe_log_clear(); |
6212dd29 MH |
828 | kfree(symbol); |
829 | return ret; | |
413d37d1 | 830 | |
ab105a4f MH |
831 | parse_error: |
832 | ret = -EINVAL; | |
413d37d1 | 833 | error: |
c31ffb3f | 834 | free_trace_kprobe(tk); |
6212dd29 | 835 | goto out; |
413d37d1 MH |
836 | } |
837 | ||
6212dd29 | 838 | static int create_or_delete_trace_kprobe(int argc, char **argv) |
413d37d1 | 839 | { |
6212dd29 | 840 | int ret; |
02ca1521 | 841 | |
6212dd29 MH |
842 | if (argv[0][0] == '-') |
843 | return dyn_event_release(argc, argv, &trace_kprobe_ops); | |
413d37d1 | 844 | |
6212dd29 MH |
845 | ret = trace_kprobe_create(argc, (const char **)argv); |
846 | return ret == -ECANCELED ? -EINVAL : ret; | |
413d37d1 MH |
847 | } |
848 | ||
6212dd29 | 849 | static int trace_kprobe_release(struct dyn_event *ev) |
413d37d1 | 850 | { |
6212dd29 MH |
851 | struct trace_kprobe *tk = to_trace_kprobe(ev); |
852 | int ret = unregister_trace_kprobe(tk); | |
413d37d1 | 853 | |
6212dd29 MH |
854 | if (!ret) |
855 | free_trace_kprobe(tk); | |
856 | return ret; | |
413d37d1 MH |
857 | } |
858 | ||
6212dd29 | 859 | static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev) |
413d37d1 | 860 | { |
6212dd29 | 861 | struct trace_kprobe *tk = to_trace_kprobe(ev); |
93ccae7a | 862 | int i; |
413d37d1 | 863 | |
fa6f0cc7 | 864 | seq_putc(m, trace_kprobe_is_return(tk) ? 'r' : 'p'); |
b55ce203 MH |
865 | seq_printf(m, ":%s/%s", trace_probe_group_name(&tk->tp), |
866 | trace_probe_name(&tk->tp)); | |
413d37d1 | 867 | |
c31ffb3f NK |
868 | if (!tk->symbol) |
869 | seq_printf(m, " 0x%p", tk->rp.kp.addr); | |
870 | else if (tk->rp.kp.offset) | |
871 | seq_printf(m, " %s+%u", trace_kprobe_symbol(tk), | |
872 | tk->rp.kp.offset); | |
413d37d1 | 873 | else |
c31ffb3f | 874 | seq_printf(m, " %s", trace_kprobe_symbol(tk)); |
413d37d1 | 875 | |
c31ffb3f NK |
876 | for (i = 0; i < tk->tp.nr_args; i++) |
877 | seq_printf(m, " %s=%s", tk->tp.args[i].name, tk->tp.args[i].comm); | |
fa6f0cc7 | 878 | seq_putc(m, '\n'); |
93ccae7a | 879 | |
413d37d1 MH |
880 | return 0; |
881 | } | |
882 | ||
6212dd29 MH |
883 | static int probes_seq_show(struct seq_file *m, void *v) |
884 | { | |
885 | struct dyn_event *ev = v; | |
886 | ||
887 | if (!is_trace_kprobe(ev)) | |
888 | return 0; | |
889 | ||
890 | return trace_kprobe_show(m, ev); | |
891 | } | |
892 | ||
413d37d1 | 893 | static const struct seq_operations probes_seq_op = { |
6212dd29 MH |
894 | .start = dyn_event_seq_start, |
895 | .next = dyn_event_seq_next, | |
896 | .stop = dyn_event_seq_stop, | |
413d37d1 MH |
897 | .show = probes_seq_show |
898 | }; | |
899 | ||
900 | static int probes_open(struct inode *inode, struct file *file) | |
901 | { | |
02ca1521 MH |
902 | int ret; |
903 | ||
904 | if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { | |
6212dd29 | 905 | ret = dyn_events_release_all(&trace_kprobe_ops); |
02ca1521 MH |
906 | if (ret < 0) |
907 | return ret; | |
908 | } | |
413d37d1 MH |
909 | |
910 | return seq_open(file, &probes_seq_op); | |
911 | } | |
912 | ||
413d37d1 MH |
913 | static ssize_t probes_write(struct file *file, const char __user *buffer, |
914 | size_t count, loff_t *ppos) | |
915 | { | |
7e465baa | 916 | return trace_parse_run_command(file, buffer, count, ppos, |
6212dd29 | 917 | create_or_delete_trace_kprobe); |
413d37d1 MH |
918 | } |
919 | ||
920 | static const struct file_operations kprobe_events_ops = { | |
921 | .owner = THIS_MODULE, | |
922 | .open = probes_open, | |
923 | .read = seq_read, | |
924 | .llseek = seq_lseek, | |
925 | .release = seq_release, | |
926 | .write = probes_write, | |
927 | }; | |
928 | ||
cd7e7bd5 MH |
929 | /* Probes profiling interfaces */ |
930 | static int probes_profile_seq_show(struct seq_file *m, void *v) | |
931 | { | |
6212dd29 MH |
932 | struct dyn_event *ev = v; |
933 | struct trace_kprobe *tk; | |
cd7e7bd5 | 934 | |
6212dd29 MH |
935 | if (!is_trace_kprobe(ev)) |
936 | return 0; | |
cd7e7bd5 | 937 | |
6212dd29 | 938 | tk = to_trace_kprobe(ev); |
de7b2973 | 939 | seq_printf(m, " %-44s %15lu %15lu\n", |
b55ce203 | 940 | trace_probe_name(&tk->tp), |
f18f97ac | 941 | trace_kprobe_nhit(tk), |
c31ffb3f | 942 | tk->rp.kp.nmissed); |
cd7e7bd5 MH |
943 | |
944 | return 0; | |
945 | } | |
946 | ||
947 | static const struct seq_operations profile_seq_op = { | |
6212dd29 MH |
948 | .start = dyn_event_seq_start, |
949 | .next = dyn_event_seq_next, | |
950 | .stop = dyn_event_seq_stop, | |
cd7e7bd5 MH |
951 | .show = probes_profile_seq_show |
952 | }; | |
953 | ||
954 | static int profile_open(struct inode *inode, struct file *file) | |
955 | { | |
956 | return seq_open(file, &profile_seq_op); | |
957 | } | |
958 | ||
959 | static const struct file_operations kprobe_profile_ops = { | |
960 | .owner = THIS_MODULE, | |
961 | .open = profile_open, | |
962 | .read = seq_read, | |
963 | .llseek = seq_lseek, | |
964 | .release = seq_release, | |
965 | }; | |
966 | ||
53305928 MH |
967 | /* Kprobe specific fetch functions */ |
968 | ||
969 | /* Return the length of string -- including null terminal byte */ | |
9178412d MH |
970 | static nokprobe_inline int |
971 | fetch_store_strlen(unsigned long addr) | |
53305928 | 972 | { |
53305928 MH |
973 | int ret, len = 0; |
974 | u8 c; | |
975 | ||
53305928 | 976 | do { |
49ef5f45 | 977 | ret = probe_kernel_read(&c, (u8 *)addr + len, 1); |
53305928 MH |
978 | len++; |
979 | } while (c && ret == 0 && len < MAX_STRING_SIZE); | |
980 | ||
9178412d | 981 | return (ret < 0) ? ret : len; |
53305928 MH |
982 | } |
983 | ||
88903c46 MH |
984 | /* Return the length of string -- including null terminal byte */ |
985 | static nokprobe_inline int | |
986 | fetch_store_strlen_user(unsigned long addr) | |
987 | { | |
988 | const void __user *uaddr = (__force const void __user *)addr; | |
989 | ||
990 | return strnlen_unsafe_user(uaddr, MAX_STRING_SIZE); | |
991 | } | |
992 | ||
53305928 MH |
993 | /* |
994 | * Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max | |
995 | * length and relative data location. | |
996 | */ | |
9178412d MH |
997 | static nokprobe_inline int |
998 | fetch_store_string(unsigned long addr, void *dest, void *base) | |
53305928 | 999 | { |
9178412d | 1000 | int maxlen = get_loc_len(*(u32 *)dest); |
88903c46 | 1001 | void *__dest; |
53305928 MH |
1002 | long ret; |
1003 | ||
9178412d MH |
1004 | if (unlikely(!maxlen)) |
1005 | return -ENOMEM; | |
88903c46 MH |
1006 | |
1007 | __dest = get_loc_data(dest, base); | |
1008 | ||
53305928 MH |
1009 | /* |
1010 | * Try to get string again, since the string can be changed while | |
1011 | * probing. | |
1012 | */ | |
88903c46 MH |
1013 | ret = strncpy_from_unsafe(__dest, (void *)addr, maxlen); |
1014 | if (ret >= 0) | |
1015 | *(u32 *)dest = make_data_loc(ret, __dest - base); | |
1016 | ||
1017 | return ret; | |
1018 | } | |
53305928 | 1019 | |
88903c46 MH |
1020 | /* |
1021 | * Fetch a null-terminated string from user. Caller MUST set *(u32 *)buf | |
1022 | * with max length and relative data location. | |
1023 | */ | |
1024 | static nokprobe_inline int | |
1025 | fetch_store_string_user(unsigned long addr, void *dest, void *base) | |
1026 | { | |
1027 | const void __user *uaddr = (__force const void __user *)addr; | |
1028 | int maxlen = get_loc_len(*(u32 *)dest); | |
1029 | void *__dest; | |
1030 | long ret; | |
1031 | ||
1032 | if (unlikely(!maxlen)) | |
1033 | return -ENOMEM; | |
1034 | ||
1035 | __dest = get_loc_data(dest, base); | |
1036 | ||
1037 | ret = strncpy_from_unsafe_user(__dest, uaddr, maxlen); | |
9178412d | 1038 | if (ret >= 0) |
88903c46 MH |
1039 | *(u32 *)dest = make_data_loc(ret, __dest - base); |
1040 | ||
9178412d | 1041 | return ret; |
53305928 MH |
1042 | } |
1043 | ||
9b960a38 MH |
1044 | static nokprobe_inline int |
1045 | probe_mem_read(void *dest, void *src, size_t size) | |
1046 | { | |
1047 | return probe_kernel_read(dest, src, size); | |
1048 | } | |
1049 | ||
e65f7ae7 MH |
1050 | static nokprobe_inline int |
1051 | probe_mem_read_user(void *dest, void *src, size_t size) | |
1052 | { | |
539b75b2 MH |
1053 | const void __user *uaddr = (__force const void __user *)src; |
1054 | ||
1055 | return probe_user_read(dest, uaddr, size); | |
e65f7ae7 MH |
1056 | } |
1057 | ||
53305928 MH |
1058 | /* Note that we don't verify it, since the code does not come from user space */ |
1059 | static int | |
1060 | process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest, | |
9178412d | 1061 | void *base) |
53305928 MH |
1062 | { |
1063 | unsigned long val; | |
53305928 | 1064 | |
a6682814 | 1065 | retry: |
53305928 MH |
1066 | /* 1st stage: get value from context */ |
1067 | switch (code->op) { | |
1068 | case FETCH_OP_REG: | |
1069 | val = regs_get_register(regs, code->param); | |
1070 | break; | |
1071 | case FETCH_OP_STACK: | |
1072 | val = regs_get_kernel_stack_nth(regs, code->param); | |
1073 | break; | |
1074 | case FETCH_OP_STACKP: | |
1075 | val = kernel_stack_pointer(regs); | |
1076 | break; | |
1077 | case FETCH_OP_RETVAL: | |
1078 | val = regs_return_value(regs); | |
1079 | break; | |
1080 | case FETCH_OP_IMM: | |
1081 | val = code->immediate; | |
1082 | break; | |
1083 | case FETCH_OP_COMM: | |
1084 | val = (unsigned long)current->comm; | |
1085 | break; | |
a42e3c4d MH |
1086 | case FETCH_OP_DATA: |
1087 | val = (unsigned long)code->data; | |
1088 | break; | |
a1303af5 MH |
1089 | #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API |
1090 | case FETCH_OP_ARG: | |
1091 | val = regs_get_kernel_argument(regs, code->param); | |
1092 | break; | |
1093 | #endif | |
a6682814 MH |
1094 | case FETCH_NOP_SYMBOL: /* Ignore a place holder */ |
1095 | code++; | |
1096 | goto retry; | |
53305928 MH |
1097 | default: |
1098 | return -EILSEQ; | |
1099 | } | |
1100 | code++; | |
1101 | ||
9b960a38 | 1102 | return process_fetch_insn_bottom(code, val, dest, base); |
53305928 MH |
1103 | } |
1104 | NOKPROBE_SYMBOL(process_fetch_insn) | |
1105 | ||
413d37d1 | 1106 | /* Kprobe handler */ |
3da0f180 | 1107 | static nokprobe_inline void |
c31ffb3f | 1108 | __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs, |
7f1d2f82 | 1109 | struct trace_event_file *trace_file) |
413d37d1 | 1110 | { |
93ccae7a | 1111 | struct kprobe_trace_entry_head *entry; |
413d37d1 | 1112 | struct ring_buffer_event *event; |
8f8ffe24 | 1113 | struct ring_buffer *buffer; |
e09c8614 | 1114 | int size, dsize, pc; |
413d37d1 | 1115 | unsigned long irq_flags; |
e3dc9f89 | 1116 | struct trace_event_call *call = trace_probe_event_call(&tk->tp); |
413d37d1 | 1117 | |
7f1d2f82 | 1118 | WARN_ON(call != trace_file->event_call); |
41a7dd42 | 1119 | |
09a5059a | 1120 | if (trace_trigger_soft_disabled(trace_file)) |
13a1e4ae | 1121 | return; |
b8820084 | 1122 | |
413d37d1 MH |
1123 | local_save_flags(irq_flags); |
1124 | pc = preempt_count(); | |
1125 | ||
c31ffb3f NK |
1126 | dsize = __get_data_size(&tk->tp, regs); |
1127 | size = sizeof(*entry) + tk->tp.size + dsize; | |
413d37d1 | 1128 | |
7f1d2f82 | 1129 | event = trace_event_buffer_lock_reserve(&buffer, trace_file, |
41a7dd42 MH |
1130 | call->event.type, |
1131 | size, irq_flags, pc); | |
413d37d1 | 1132 | if (!event) |
1e12a4a7 | 1133 | return; |
413d37d1 MH |
1134 | |
1135 | entry = ring_buffer_event_data(event); | |
c31ffb3f | 1136 | entry->ip = (unsigned long)tk->rp.kp.addr; |
9178412d | 1137 | store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize); |
413d37d1 | 1138 | |
7f1d2f82 | 1139 | event_trigger_unlock_commit_regs(trace_file, buffer, event, |
13a1e4ae | 1140 | entry, irq_flags, pc, regs); |
413d37d1 MH |
1141 | } |
1142 | ||
3da0f180 | 1143 | static void |
c31ffb3f | 1144 | kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs) |
41a7dd42 | 1145 | { |
b04d52e3 | 1146 | struct event_file_link *link; |
41a7dd42 | 1147 | |
b5f935ee | 1148 | trace_probe_for_each_link_rcu(link, &tk->tp) |
c31ffb3f | 1149 | __kprobe_trace_func(tk, regs, link->file); |
41a7dd42 | 1150 | } |
3da0f180 | 1151 | NOKPROBE_SYMBOL(kprobe_trace_func); |
41a7dd42 | 1152 | |
413d37d1 | 1153 | /* Kretprobe handler */ |
3da0f180 | 1154 | static nokprobe_inline void |
c31ffb3f | 1155 | __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, |
41a7dd42 | 1156 | struct pt_regs *regs, |
7f1d2f82 | 1157 | struct trace_event_file *trace_file) |
413d37d1 | 1158 | { |
93ccae7a | 1159 | struct kretprobe_trace_entry_head *entry; |
413d37d1 | 1160 | struct ring_buffer_event *event; |
8f8ffe24 | 1161 | struct ring_buffer *buffer; |
e09c8614 | 1162 | int size, pc, dsize; |
413d37d1 | 1163 | unsigned long irq_flags; |
e3dc9f89 | 1164 | struct trace_event_call *call = trace_probe_event_call(&tk->tp); |
413d37d1 | 1165 | |
7f1d2f82 | 1166 | WARN_ON(call != trace_file->event_call); |
41a7dd42 | 1167 | |
09a5059a | 1168 | if (trace_trigger_soft_disabled(trace_file)) |
13a1e4ae | 1169 | return; |
b8820084 | 1170 | |
413d37d1 MH |
1171 | local_save_flags(irq_flags); |
1172 | pc = preempt_count(); | |
1173 | ||
c31ffb3f NK |
1174 | dsize = __get_data_size(&tk->tp, regs); |
1175 | size = sizeof(*entry) + tk->tp.size + dsize; | |
413d37d1 | 1176 | |
7f1d2f82 | 1177 | event = trace_event_buffer_lock_reserve(&buffer, trace_file, |
41a7dd42 MH |
1178 | call->event.type, |
1179 | size, irq_flags, pc); | |
413d37d1 | 1180 | if (!event) |
1e12a4a7 | 1181 | return; |
413d37d1 MH |
1182 | |
1183 | entry = ring_buffer_event_data(event); | |
c31ffb3f | 1184 | entry->func = (unsigned long)tk->rp.kp.addr; |
413d37d1 | 1185 | entry->ret_ip = (unsigned long)ri->ret_addr; |
9178412d | 1186 | store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize); |
413d37d1 | 1187 | |
7f1d2f82 | 1188 | event_trigger_unlock_commit_regs(trace_file, buffer, event, |
13a1e4ae | 1189 | entry, irq_flags, pc, regs); |
413d37d1 MH |
1190 | } |
1191 | ||
3da0f180 | 1192 | static void |
c31ffb3f | 1193 | kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, |
41a7dd42 MH |
1194 | struct pt_regs *regs) |
1195 | { | |
b04d52e3 | 1196 | struct event_file_link *link; |
41a7dd42 | 1197 | |
b5f935ee | 1198 | trace_probe_for_each_link_rcu(link, &tk->tp) |
c31ffb3f | 1199 | __kretprobe_trace_func(tk, ri, regs, link->file); |
41a7dd42 | 1200 | } |
3da0f180 | 1201 | NOKPROBE_SYMBOL(kretprobe_trace_func); |
41a7dd42 | 1202 | |
413d37d1 | 1203 | /* Event entry printers */ |
b62fdd97 | 1204 | static enum print_line_t |
a9a57763 SR |
1205 | print_kprobe_event(struct trace_iterator *iter, int flags, |
1206 | struct trace_event *event) | |
413d37d1 | 1207 | { |
93ccae7a | 1208 | struct kprobe_trace_entry_head *field; |
413d37d1 | 1209 | struct trace_seq *s = &iter->seq; |
eca0d916 | 1210 | struct trace_probe *tp; |
413d37d1 | 1211 | |
93ccae7a | 1212 | field = (struct kprobe_trace_entry_head *)iter->ent; |
60d53e2c MH |
1213 | tp = trace_probe_primary_from_call( |
1214 | container_of(event, struct trace_event_call, event)); | |
1215 | if (WARN_ON_ONCE(!tp)) | |
1216 | goto out; | |
413d37d1 | 1217 | |
b55ce203 | 1218 | trace_seq_printf(s, "%s: (", trace_probe_name(tp)); |
6e9f23d1 | 1219 | |
413d37d1 | 1220 | if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET)) |
85224da0 | 1221 | goto out; |
413d37d1 | 1222 | |
85224da0 | 1223 | trace_seq_putc(s, ')'); |
413d37d1 | 1224 | |
56de7630 MH |
1225 | if (print_probe_args(s, tp->args, tp->nr_args, |
1226 | (u8 *)&field[1], field) < 0) | |
1227 | goto out; | |
413d37d1 | 1228 | |
85224da0 SRRH |
1229 | trace_seq_putc(s, '\n'); |
1230 | out: | |
1231 | return trace_handle_return(s); | |
413d37d1 MH |
1232 | } |
1233 | ||
b62fdd97 | 1234 | static enum print_line_t |
a9a57763 SR |
1235 | print_kretprobe_event(struct trace_iterator *iter, int flags, |
1236 | struct trace_event *event) | |
413d37d1 | 1237 | { |
93ccae7a | 1238 | struct kretprobe_trace_entry_head *field; |
413d37d1 | 1239 | struct trace_seq *s = &iter->seq; |
eca0d916 | 1240 | struct trace_probe *tp; |
413d37d1 | 1241 | |
93ccae7a | 1242 | field = (struct kretprobe_trace_entry_head *)iter->ent; |
60d53e2c MH |
1243 | tp = trace_probe_primary_from_call( |
1244 | container_of(event, struct trace_event_call, event)); | |
1245 | if (WARN_ON_ONCE(!tp)) | |
1246 | goto out; | |
413d37d1 | 1247 | |
b55ce203 | 1248 | trace_seq_printf(s, "%s: (", trace_probe_name(tp)); |
6e9f23d1 | 1249 | |
413d37d1 | 1250 | if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET)) |
85224da0 | 1251 | goto out; |
413d37d1 | 1252 | |
85224da0 | 1253 | trace_seq_puts(s, " <- "); |
413d37d1 MH |
1254 | |
1255 | if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET)) | |
85224da0 | 1256 | goto out; |
413d37d1 | 1257 | |
85224da0 | 1258 | trace_seq_putc(s, ')'); |
413d37d1 | 1259 | |
56de7630 MH |
1260 | if (print_probe_args(s, tp->args, tp->nr_args, |
1261 | (u8 *)&field[1], field) < 0) | |
1262 | goto out; | |
413d37d1 | 1263 | |
85224da0 | 1264 | trace_seq_putc(s, '\n'); |
413d37d1 | 1265 | |
85224da0 SRRH |
1266 | out: |
1267 | return trace_handle_return(s); | |
413d37d1 MH |
1268 | } |
1269 | ||
413d37d1 | 1270 | |
2425bcb9 | 1271 | static int kprobe_event_define_fields(struct trace_event_call *event_call) |
413d37d1 | 1272 | { |
eeb07b06 | 1273 | int ret; |
93ccae7a | 1274 | struct kprobe_trace_entry_head field; |
60d53e2c MH |
1275 | struct trace_probe *tp; |
1276 | ||
1277 | tp = trace_probe_primary_from_call(event_call); | |
1278 | if (WARN_ON_ONCE(!tp)) | |
1279 | return -ENOENT; | |
413d37d1 | 1280 | |
a703d946 | 1281 | DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0); |
c31ffb3f | 1282 | |
60d53e2c | 1283 | return traceprobe_define_arg_fields(event_call, sizeof(field), tp); |
413d37d1 MH |
1284 | } |
1285 | ||
2425bcb9 | 1286 | static int kretprobe_event_define_fields(struct trace_event_call *event_call) |
413d37d1 | 1287 | { |
eeb07b06 | 1288 | int ret; |
93ccae7a | 1289 | struct kretprobe_trace_entry_head field; |
60d53e2c MH |
1290 | struct trace_probe *tp; |
1291 | ||
1292 | tp = trace_probe_primary_from_call(event_call); | |
1293 | if (WARN_ON_ONCE(!tp)) | |
1294 | return -ENOENT; | |
413d37d1 | 1295 | |
a703d946 MH |
1296 | DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0); |
1297 | DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0); | |
c31ffb3f | 1298 | |
60d53e2c | 1299 | return traceprobe_define_arg_fields(event_call, sizeof(field), tp); |
413d37d1 MH |
1300 | } |
1301 | ||
07b139c8 | 1302 | #ifdef CONFIG_PERF_EVENTS |
e08d1c65 MH |
1303 | |
1304 | /* Kprobe profile handler */ | |
9802d865 | 1305 | static int |
c31ffb3f | 1306 | kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs) |
e08d1c65 | 1307 | { |
e3dc9f89 | 1308 | struct trace_event_call *call = trace_probe_event_call(&tk->tp); |
93ccae7a | 1309 | struct kprobe_trace_entry_head *entry; |
1c024eca | 1310 | struct hlist_head *head; |
e09c8614 | 1311 | int size, __size, dsize; |
4ed7c92d | 1312 | int rctx; |
e08d1c65 | 1313 | |
9802d865 | 1314 | if (bpf_prog_array_valid(call)) { |
66665ad2 | 1315 | unsigned long orig_ip = instruction_pointer(regs); |
9802d865 JB |
1316 | int ret; |
1317 | ||
1318 | ret = trace_call_bpf(call, regs); | |
1319 | ||
1320 | /* | |
1321 | * We need to check and see if we modified the pc of the | |
cce188bd MH |
1322 | * pt_regs, and if so return 1 so that we don't do the |
1323 | * single stepping. | |
9802d865 | 1324 | */ |
cce188bd | 1325 | if (orig_ip != instruction_pointer(regs)) |
9802d865 | 1326 | return 1; |
9802d865 JB |
1327 | if (!ret) |
1328 | return 0; | |
1329 | } | |
2541517c | 1330 | |
288e984e ON |
1331 | head = this_cpu_ptr(call->perf_events); |
1332 | if (hlist_empty(head)) | |
9802d865 | 1333 | return 0; |
288e984e | 1334 | |
c31ffb3f NK |
1335 | dsize = __get_data_size(&tk->tp, regs); |
1336 | __size = sizeof(*entry) + tk->tp.size + dsize; | |
74ebb63e MH |
1337 | size = ALIGN(__size + sizeof(u32), sizeof(u64)); |
1338 | size -= sizeof(u32); | |
ce71b9df | 1339 | |
1e1dcd93 | 1340 | entry = perf_trace_buf_alloc(size, NULL, &rctx); |
430ad5a6 | 1341 | if (!entry) |
9802d865 | 1342 | return 0; |
a1a138d0 | 1343 | |
c31ffb3f | 1344 | entry->ip = (unsigned long)tk->rp.kp.addr; |
e09c8614 | 1345 | memset(&entry[1], 0, dsize); |
9178412d | 1346 | store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize); |
1e1dcd93 | 1347 | perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, |
8fd0fbbe | 1348 | head, NULL); |
9802d865 | 1349 | return 0; |
e08d1c65 | 1350 | } |
3da0f180 | 1351 | NOKPROBE_SYMBOL(kprobe_perf_func); |
e08d1c65 MH |
1352 | |
1353 | /* Kretprobe profile handler */ | |
3da0f180 | 1354 | static void |
c31ffb3f | 1355 | kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, |
2b106aab | 1356 | struct pt_regs *regs) |
e08d1c65 | 1357 | { |
e3dc9f89 | 1358 | struct trace_event_call *call = trace_probe_event_call(&tk->tp); |
93ccae7a | 1359 | struct kretprobe_trace_entry_head *entry; |
1c024eca | 1360 | struct hlist_head *head; |
e09c8614 | 1361 | int size, __size, dsize; |
4ed7c92d | 1362 | int rctx; |
e08d1c65 | 1363 | |
e87c6bc3 | 1364 | if (bpf_prog_array_valid(call) && !trace_call_bpf(call, regs)) |
2541517c AS |
1365 | return; |
1366 | ||
288e984e ON |
1367 | head = this_cpu_ptr(call->perf_events); |
1368 | if (hlist_empty(head)) | |
1369 | return; | |
1370 | ||
c31ffb3f NK |
1371 | dsize = __get_data_size(&tk->tp, regs); |
1372 | __size = sizeof(*entry) + tk->tp.size + dsize; | |
74ebb63e MH |
1373 | size = ALIGN(__size + sizeof(u32), sizeof(u64)); |
1374 | size -= sizeof(u32); | |
444a2a3b | 1375 | |
1e1dcd93 | 1376 | entry = perf_trace_buf_alloc(size, NULL, &rctx); |
430ad5a6 | 1377 | if (!entry) |
1e12a4a7 | 1378 | return; |
e08d1c65 | 1379 | |
c31ffb3f | 1380 | entry->func = (unsigned long)tk->rp.kp.addr; |
a1a138d0 | 1381 | entry->ret_ip = (unsigned long)ri->ret_addr; |
9178412d | 1382 | store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize); |
1e1dcd93 | 1383 | perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, |
8fd0fbbe | 1384 | head, NULL); |
e08d1c65 | 1385 | } |
3da0f180 | 1386 | NOKPROBE_SYMBOL(kretprobe_perf_func); |
41bdc4b4 YS |
1387 | |
1388 | int bpf_get_kprobe_info(const struct perf_event *event, u32 *fd_type, | |
1389 | const char **symbol, u64 *probe_offset, | |
1390 | u64 *probe_addr, bool perf_type_tracepoint) | |
1391 | { | |
1392 | const char *pevent = trace_event_name(event->tp_event); | |
1393 | const char *group = event->tp_event->class->system; | |
1394 | struct trace_kprobe *tk; | |
1395 | ||
1396 | if (perf_type_tracepoint) | |
1397 | tk = find_trace_kprobe(pevent, group); | |
1398 | else | |
1399 | tk = event->tp_event->data; | |
1400 | if (!tk) | |
1401 | return -EINVAL; | |
1402 | ||
1403 | *fd_type = trace_kprobe_is_return(tk) ? BPF_FD_TYPE_KRETPROBE | |
1404 | : BPF_FD_TYPE_KPROBE; | |
1405 | if (tk->symbol) { | |
1406 | *symbol = tk->symbol; | |
1407 | *probe_offset = tk->rp.kp.offset; | |
1408 | *probe_addr = 0; | |
1409 | } else { | |
1410 | *symbol = NULL; | |
1411 | *probe_offset = 0; | |
1412 | *probe_addr = (unsigned long)tk->rp.kp.addr; | |
1413 | } | |
1414 | return 0; | |
1415 | } | |
07b139c8 | 1416 | #endif /* CONFIG_PERF_EVENTS */ |
50d78056 | 1417 | |
3fe3d619 ON |
1418 | /* |
1419 | * called by perf_trace_init() or __ftrace_set_clr_event() under event_mutex. | |
1420 | * | |
1421 | * kprobe_trace_self_tests_init() does enable_trace_probe/disable_trace_probe | |
1422 | * lockless, but we can't race with this __init function. | |
1423 | */ | |
2425bcb9 | 1424 | static int kprobe_register(struct trace_event_call *event, |
fbc1963d | 1425 | enum trace_reg type, void *data) |
2239291a | 1426 | { |
7f1d2f82 | 1427 | struct trace_event_file *file = data; |
1538f888 | 1428 | |
2239291a SR |
1429 | switch (type) { |
1430 | case TRACE_REG_REGISTER: | |
60d53e2c | 1431 | return enable_trace_kprobe(event, file); |
2239291a | 1432 | case TRACE_REG_UNREGISTER: |
60d53e2c | 1433 | return disable_trace_kprobe(event, file); |
2239291a SR |
1434 | |
1435 | #ifdef CONFIG_PERF_EVENTS | |
1436 | case TRACE_REG_PERF_REGISTER: | |
60d53e2c | 1437 | return enable_trace_kprobe(event, NULL); |
2239291a | 1438 | case TRACE_REG_PERF_UNREGISTER: |
60d53e2c | 1439 | return disable_trace_kprobe(event, NULL); |
ceec0b6f JO |
1440 | case TRACE_REG_PERF_OPEN: |
1441 | case TRACE_REG_PERF_CLOSE: | |
489c75c3 JO |
1442 | case TRACE_REG_PERF_ADD: |
1443 | case TRACE_REG_PERF_DEL: | |
ceec0b6f | 1444 | return 0; |
2239291a SR |
1445 | #endif |
1446 | } | |
1447 | return 0; | |
1448 | } | |
50d78056 | 1449 | |
3da0f180 | 1450 | static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs) |
50d78056 | 1451 | { |
c31ffb3f | 1452 | struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp); |
9802d865 | 1453 | int ret = 0; |
e08d1c65 | 1454 | |
a7636d9e | 1455 | raw_cpu_inc(*tk->nhit); |
48182bd2 | 1456 | |
747774d6 | 1457 | if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE)) |
c31ffb3f | 1458 | kprobe_trace_func(tk, regs); |
07b139c8 | 1459 | #ifdef CONFIG_PERF_EVENTS |
747774d6 | 1460 | if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE)) |
9802d865 | 1461 | ret = kprobe_perf_func(tk, regs); |
07b139c8 | 1462 | #endif |
9802d865 | 1463 | return ret; |
50d78056 | 1464 | } |
3da0f180 | 1465 | NOKPROBE_SYMBOL(kprobe_dispatcher); |
50d78056 | 1466 | |
3da0f180 MH |
1467 | static int |
1468 | kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs) | |
50d78056 | 1469 | { |
c31ffb3f | 1470 | struct trace_kprobe *tk = container_of(ri->rp, struct trace_kprobe, rp); |
50d78056 | 1471 | |
a7636d9e | 1472 | raw_cpu_inc(*tk->nhit); |
48182bd2 | 1473 | |
747774d6 | 1474 | if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE)) |
c31ffb3f | 1475 | kretprobe_trace_func(tk, ri, regs); |
07b139c8 | 1476 | #ifdef CONFIG_PERF_EVENTS |
747774d6 | 1477 | if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE)) |
c31ffb3f | 1478 | kretprobe_perf_func(tk, ri, regs); |
07b139c8 | 1479 | #endif |
50d78056 MH |
1480 | return 0; /* We don't tweek kernel, so just return 0 */ |
1481 | } | |
3da0f180 | 1482 | NOKPROBE_SYMBOL(kretprobe_dispatcher); |
e08d1c65 | 1483 | |
a9a57763 SR |
1484 | static struct trace_event_functions kretprobe_funcs = { |
1485 | .trace = print_kretprobe_event | |
1486 | }; | |
1487 | ||
1488 | static struct trace_event_functions kprobe_funcs = { | |
1489 | .trace = print_kprobe_event | |
1490 | }; | |
1491 | ||
e3dc9f89 | 1492 | static inline void init_trace_event_call(struct trace_kprobe *tk) |
413d37d1 | 1493 | { |
e3dc9f89 MH |
1494 | struct trace_event_call *call = trace_probe_event_call(&tk->tp); |
1495 | ||
c31ffb3f | 1496 | if (trace_kprobe_is_return(tk)) { |
80decc70 | 1497 | call->event.funcs = &kretprobe_funcs; |
2e33af02 | 1498 | call->class->define_fields = kretprobe_event_define_fields; |
413d37d1 | 1499 | } else { |
80decc70 | 1500 | call->event.funcs = &kprobe_funcs; |
2e33af02 | 1501 | call->class->define_fields = kprobe_event_define_fields; |
413d37d1 | 1502 | } |
e12f03d7 SL |
1503 | |
1504 | call->flags = TRACE_EVENT_FL_KPROBE; | |
1505 | call->class->reg = kprobe_register; | |
e12f03d7 SL |
1506 | } |
1507 | ||
1508 | static int register_kprobe_event(struct trace_kprobe *tk) | |
1509 | { | |
e3dc9f89 | 1510 | init_trace_event_call(tk); |
f730e0f2 | 1511 | |
46e5376d | 1512 | return trace_probe_register_event_call(&tk->tp); |
413d37d1 MH |
1513 | } |
1514 | ||
c31ffb3f | 1515 | static int unregister_kprobe_event(struct trace_kprobe *tk) |
413d37d1 | 1516 | { |
46e5376d | 1517 | return trace_probe_unregister_event_call(&tk->tp); |
413d37d1 MH |
1518 | } |
1519 | ||
e12f03d7 SL |
1520 | #ifdef CONFIG_PERF_EVENTS |
1521 | /* create a trace_kprobe, but don't add it to global lists */ | |
1522 | struct trace_event_call * | |
1523 | create_local_trace_kprobe(char *func, void *addr, unsigned long offs, | |
1524 | bool is_return) | |
1525 | { | |
1526 | struct trace_kprobe *tk; | |
1527 | int ret; | |
1528 | char *event; | |
1529 | ||
1530 | /* | |
6212dd29 | 1531 | * local trace_kprobes are not added to dyn_event, so they are never |
e12f03d7 SL |
1532 | * searched in find_trace_kprobe(). Therefore, there is no concern of |
1533 | * duplicated name here. | |
1534 | */ | |
1535 | event = func ? func : "DUMMY_EVENT"; | |
1536 | ||
1537 | tk = alloc_trace_kprobe(KPROBE_EVENT_SYSTEM, event, (void *)addr, func, | |
1538 | offs, 0 /* maxactive */, 0 /* nargs */, | |
1539 | is_return); | |
1540 | ||
1541 | if (IS_ERR(tk)) { | |
1542 | pr_info("Failed to allocate trace_probe.(%d)\n", | |
1543 | (int)PTR_ERR(tk)); | |
1544 | return ERR_CAST(tk); | |
1545 | } | |
1546 | ||
e3dc9f89 | 1547 | init_trace_event_call(tk); |
e12f03d7 | 1548 | |
0a46c854 | 1549 | if (traceprobe_set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) { |
e12f03d7 SL |
1550 | ret = -ENOMEM; |
1551 | goto error; | |
1552 | } | |
1553 | ||
1554 | ret = __register_trace_kprobe(tk); | |
f730e0f2 | 1555 | if (ret < 0) |
e12f03d7 SL |
1556 | goto error; |
1557 | ||
e3dc9f89 | 1558 | return trace_probe_event_call(&tk->tp); |
e12f03d7 SL |
1559 | error: |
1560 | free_trace_kprobe(tk); | |
1561 | return ERR_PTR(ret); | |
1562 | } | |
1563 | ||
1564 | void destroy_local_trace_kprobe(struct trace_event_call *event_call) | |
1565 | { | |
1566 | struct trace_kprobe *tk; | |
1567 | ||
60d53e2c MH |
1568 | tk = trace_kprobe_primary_from_call(event_call); |
1569 | if (unlikely(!tk)) | |
1570 | return; | |
e12f03d7 SL |
1571 | |
1572 | if (trace_probe_is_enabled(&tk->tp)) { | |
1573 | WARN_ON(1); | |
1574 | return; | |
1575 | } | |
1576 | ||
1577 | __unregister_trace_kprobe(tk); | |
0fc8c358 | 1578 | |
e12f03d7 SL |
1579 | free_trace_kprobe(tk); |
1580 | } | |
1581 | #endif /* CONFIG_PERF_EVENTS */ | |
1582 | ||
970988e1 MH |
1583 | static __init void enable_boot_kprobe_events(void) |
1584 | { | |
1585 | struct trace_array *tr = top_trace_array(); | |
1586 | struct trace_event_file *file; | |
1587 | struct trace_kprobe *tk; | |
1588 | struct dyn_event *pos; | |
1589 | ||
1590 | mutex_lock(&event_mutex); | |
1591 | for_each_trace_kprobe(tk, pos) { | |
1592 | list_for_each_entry(file, &tr->events, list) | |
e3dc9f89 | 1593 | if (file->event_call == trace_probe_event_call(&tk->tp)) |
970988e1 MH |
1594 | trace_event_enable_disable(file, 1, 0); |
1595 | } | |
1596 | mutex_unlock(&event_mutex); | |
1597 | } | |
1598 | ||
1599 | static __init void setup_boot_kprobe_events(void) | |
1600 | { | |
1601 | char *p, *cmd = kprobe_boot_events_buf; | |
1602 | int ret; | |
1603 | ||
1604 | strreplace(kprobe_boot_events_buf, ',', ' '); | |
1605 | ||
1606 | while (cmd && *cmd != '\0') { | |
1607 | p = strchr(cmd, ';'); | |
1608 | if (p) | |
1609 | *p++ = '\0'; | |
1610 | ||
1611 | ret = trace_run_command(cmd, create_or_delete_trace_kprobe); | |
1612 | if (ret) | |
1613 | pr_warn("Failed to add event(%d): %s\n", ret, cmd); | |
b6399cc7 SRV |
1614 | else |
1615 | kprobe_boot_events_enabled = true; | |
970988e1 MH |
1616 | |
1617 | cmd = p; | |
1618 | } | |
1619 | ||
1620 | enable_boot_kprobe_events(); | |
1621 | } | |
1622 | ||
8434dc93 | 1623 | /* Make a tracefs interface for controlling probe points */ |
413d37d1 MH |
1624 | static __init int init_kprobe_trace(void) |
1625 | { | |
1626 | struct dentry *d_tracer; | |
1627 | struct dentry *entry; | |
6212dd29 MH |
1628 | int ret; |
1629 | ||
1630 | ret = dyn_event_register(&trace_kprobe_ops); | |
1631 | if (ret) | |
1632 | return ret; | |
413d37d1 | 1633 | |
c31ffb3f | 1634 | if (register_module_notifier(&trace_kprobe_module_nb)) |
61424318 MH |
1635 | return -EINVAL; |
1636 | ||
413d37d1 | 1637 | d_tracer = tracing_init_dentry(); |
14a5ae40 | 1638 | if (IS_ERR(d_tracer)) |
413d37d1 MH |
1639 | return 0; |
1640 | ||
8434dc93 | 1641 | entry = tracefs_create_file("kprobe_events", 0644, d_tracer, |
413d37d1 MH |
1642 | NULL, &kprobe_events_ops); |
1643 | ||
cd7e7bd5 | 1644 | /* Event list interface */ |
413d37d1 | 1645 | if (!entry) |
a395d6a7 | 1646 | pr_warn("Could not create tracefs 'kprobe_events' entry\n"); |
cd7e7bd5 MH |
1647 | |
1648 | /* Profile interface */ | |
8434dc93 | 1649 | entry = tracefs_create_file("kprobe_profile", 0444, d_tracer, |
cd7e7bd5 MH |
1650 | NULL, &kprobe_profile_ops); |
1651 | ||
1652 | if (!entry) | |
a395d6a7 | 1653 | pr_warn("Could not create tracefs 'kprobe_profile' entry\n"); |
970988e1 MH |
1654 | |
1655 | setup_boot_kprobe_events(); | |
1656 | ||
413d37d1 MH |
1657 | return 0; |
1658 | } | |
1659 | fs_initcall(init_kprobe_trace); | |
1660 | ||
1661 | ||
1662 | #ifdef CONFIG_FTRACE_STARTUP_TEST | |
26a346f2 | 1663 | static __init struct trace_event_file * |
c31ffb3f | 1664 | find_trace_probe_file(struct trace_kprobe *tk, struct trace_array *tr) |
41a7dd42 | 1665 | { |
7f1d2f82 | 1666 | struct trace_event_file *file; |
41a7dd42 MH |
1667 | |
1668 | list_for_each_entry(file, &tr->events, list) | |
e3dc9f89 | 1669 | if (file->event_call == trace_probe_event_call(&tk->tp)) |
41a7dd42 MH |
1670 | return file; |
1671 | ||
1672 | return NULL; | |
1673 | } | |
1674 | ||
3fe3d619 | 1675 | /* |
c31ffb3f | 1676 | * Nobody but us can call enable_trace_kprobe/disable_trace_kprobe at this |
3fe3d619 ON |
1677 | * stage, we can do this lockless. |
1678 | */ | |
413d37d1 MH |
1679 | static __init int kprobe_trace_self_tests_init(void) |
1680 | { | |
231e36f4 | 1681 | int ret, warn = 0; |
413d37d1 | 1682 | int (*target)(int, int, int, int, int, int); |
c31ffb3f | 1683 | struct trace_kprobe *tk; |
7f1d2f82 | 1684 | struct trace_event_file *file; |
413d37d1 | 1685 | |
748ec3a2 YY |
1686 | if (tracing_is_disabled()) |
1687 | return -ENODEV; | |
1688 | ||
b6399cc7 SRV |
1689 | if (kprobe_boot_events_enabled) { |
1690 | pr_info("Skipping kprobe tests due to kprobe_event on cmdline\n"); | |
1691 | return 0; | |
1692 | } | |
1693 | ||
413d37d1 MH |
1694 | target = kprobe_trace_selftest_target; |
1695 | ||
1696 | pr_info("Testing kprobe tracing: "); | |
1697 | ||
6212dd29 MH |
1698 | ret = trace_run_command("p:testprobe kprobe_trace_selftest_target $stack $stack0 +0($stack)", |
1699 | create_or_delete_trace_kprobe); | |
231e36f4 | 1700 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1701 | pr_warn("error on probing function entry.\n"); |
231e36f4 MH |
1702 | warn++; |
1703 | } else { | |
1704 | /* Enable trace point */ | |
c31ffb3f NK |
1705 | tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM); |
1706 | if (WARN_ON_ONCE(tk == NULL)) { | |
41a7dd42 | 1707 | pr_warn("error on getting new probe.\n"); |
231e36f4 | 1708 | warn++; |
41a7dd42 | 1709 | } else { |
c31ffb3f | 1710 | file = find_trace_probe_file(tk, top_trace_array()); |
41a7dd42 MH |
1711 | if (WARN_ON_ONCE(file == NULL)) { |
1712 | pr_warn("error on getting probe file.\n"); | |
1713 | warn++; | |
1714 | } else | |
60d53e2c MH |
1715 | enable_trace_kprobe( |
1716 | trace_probe_event_call(&tk->tp), file); | |
41a7dd42 | 1717 | } |
231e36f4 | 1718 | } |
413d37d1 | 1719 | |
6212dd29 MH |
1720 | ret = trace_run_command("r:testprobe2 kprobe_trace_selftest_target $retval", |
1721 | create_or_delete_trace_kprobe); | |
231e36f4 | 1722 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1723 | pr_warn("error on probing function return.\n"); |
231e36f4 MH |
1724 | warn++; |
1725 | } else { | |
1726 | /* Enable trace point */ | |
c31ffb3f NK |
1727 | tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM); |
1728 | if (WARN_ON_ONCE(tk == NULL)) { | |
41a7dd42 | 1729 | pr_warn("error on getting 2nd new probe.\n"); |
231e36f4 | 1730 | warn++; |
41a7dd42 | 1731 | } else { |
c31ffb3f | 1732 | file = find_trace_probe_file(tk, top_trace_array()); |
41a7dd42 MH |
1733 | if (WARN_ON_ONCE(file == NULL)) { |
1734 | pr_warn("error on getting probe file.\n"); | |
1735 | warn++; | |
1736 | } else | |
60d53e2c MH |
1737 | enable_trace_kprobe( |
1738 | trace_probe_event_call(&tk->tp), file); | |
41a7dd42 | 1739 | } |
231e36f4 MH |
1740 | } |
1741 | ||
1742 | if (warn) | |
1743 | goto end; | |
413d37d1 MH |
1744 | |
1745 | ret = target(1, 2, 3, 4, 5, 6); | |
1746 | ||
d4d7ccc8 MN |
1747 | /* |
1748 | * Not expecting an error here, the check is only to prevent the | |
1749 | * optimizer from removing the call to target() as otherwise there | |
1750 | * are no side-effects and the call is never performed. | |
1751 | */ | |
1752 | if (ret != 21) | |
1753 | warn++; | |
1754 | ||
02ca1521 | 1755 | /* Disable trace points before removing it */ |
c31ffb3f NK |
1756 | tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM); |
1757 | if (WARN_ON_ONCE(tk == NULL)) { | |
41a7dd42 | 1758 | pr_warn("error on getting test probe.\n"); |
02ca1521 | 1759 | warn++; |
41a7dd42 | 1760 | } else { |
d4d7ccc8 MN |
1761 | if (trace_kprobe_nhit(tk) != 1) { |
1762 | pr_warn("incorrect number of testprobe hits\n"); | |
1763 | warn++; | |
1764 | } | |
1765 | ||
c31ffb3f | 1766 | file = find_trace_probe_file(tk, top_trace_array()); |
41a7dd42 MH |
1767 | if (WARN_ON_ONCE(file == NULL)) { |
1768 | pr_warn("error on getting probe file.\n"); | |
1769 | warn++; | |
1770 | } else | |
60d53e2c MH |
1771 | disable_trace_kprobe( |
1772 | trace_probe_event_call(&tk->tp), file); | |
41a7dd42 | 1773 | } |
02ca1521 | 1774 | |
c31ffb3f NK |
1775 | tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM); |
1776 | if (WARN_ON_ONCE(tk == NULL)) { | |
41a7dd42 | 1777 | pr_warn("error on getting 2nd test probe.\n"); |
02ca1521 | 1778 | warn++; |
41a7dd42 | 1779 | } else { |
d4d7ccc8 MN |
1780 | if (trace_kprobe_nhit(tk) != 1) { |
1781 | pr_warn("incorrect number of testprobe2 hits\n"); | |
1782 | warn++; | |
1783 | } | |
1784 | ||
c31ffb3f | 1785 | file = find_trace_probe_file(tk, top_trace_array()); |
41a7dd42 MH |
1786 | if (WARN_ON_ONCE(file == NULL)) { |
1787 | pr_warn("error on getting probe file.\n"); | |
1788 | warn++; | |
1789 | } else | |
60d53e2c MH |
1790 | disable_trace_kprobe( |
1791 | trace_probe_event_call(&tk->tp), file); | |
41a7dd42 | 1792 | } |
02ca1521 | 1793 | |
6212dd29 | 1794 | ret = trace_run_command("-:testprobe", create_or_delete_trace_kprobe); |
231e36f4 | 1795 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1796 | pr_warn("error on deleting a probe.\n"); |
231e36f4 MH |
1797 | warn++; |
1798 | } | |
1799 | ||
6212dd29 | 1800 | ret = trace_run_command("-:testprobe2", create_or_delete_trace_kprobe); |
231e36f4 | 1801 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1802 | pr_warn("error on deleting a probe.\n"); |
231e36f4 MH |
1803 | warn++; |
1804 | } | |
413d37d1 | 1805 | |
231e36f4 | 1806 | end: |
6212dd29 MH |
1807 | ret = dyn_events_release_all(&trace_kprobe_ops); |
1808 | if (WARN_ON_ONCE(ret)) { | |
1809 | pr_warn("error on cleaning up probes.\n"); | |
1810 | warn++; | |
1811 | } | |
30e7d894 TG |
1812 | /* |
1813 | * Wait for the optimizer work to finish. Otherwise it might fiddle | |
1814 | * with probes in already freed __init text. | |
1815 | */ | |
1816 | wait_for_kprobe_optimizer(); | |
231e36f4 MH |
1817 | if (warn) |
1818 | pr_cont("NG: Some tests are failed. Please check them.\n"); | |
1819 | else | |
1820 | pr_cont("OK\n"); | |
413d37d1 MH |
1821 | return 0; |
1822 | } | |
1823 | ||
1824 | late_initcall(kprobe_trace_self_tests_init); | |
1825 | ||
1826 | #endif |