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