Commit | Line | Data |
---|---|---|
413d37d1 | 1 | /* |
77b44d1b | 2 | * Kprobes-based tracing events |
413d37d1 MH |
3 | * |
4 | * Created by Masami Hiramatsu <mhiramat@redhat.com> | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program; if not, write to the Free Software | |
17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
18 | */ | |
19 | ||
20 | #include <linux/module.h> | |
21 | #include <linux/uaccess.h> | |
413d37d1 | 22 | |
8ab83f56 | 23 | #include "trace_probe.h" |
1ff511e3 | 24 | |
8ab83f56 | 25 | #define KPROBE_EVENT_SYSTEM "kprobes" |
e09c8614 | 26 | |
413d37d1 | 27 | /** |
77b44d1b | 28 | * Kprobe event core functions |
413d37d1 | 29 | */ |
413d37d1 MH |
30 | struct trace_probe { |
31 | struct list_head list; | |
4a846b44 | 32 | struct kretprobe rp; /* Use rp.kp for kprobe use */ |
cd7e7bd5 | 33 | unsigned long nhit; |
50d78056 | 34 | unsigned int flags; /* For TP_FLAG_* */ |
413d37d1 | 35 | const char *symbol; /* symbol name */ |
2239291a | 36 | struct ftrace_event_class class; |
413d37d1 | 37 | struct ftrace_event_call call; |
3d1fc7b0 | 38 | struct ftrace_event_file * __rcu *files; |
93ccae7a | 39 | ssize_t size; /* trace entry size */ |
a82378d8 | 40 | unsigned int nr_args; |
eca0d916 | 41 | struct probe_arg args[]; |
413d37d1 MH |
42 | }; |
43 | ||
a82378d8 MH |
44 | #define SIZEOF_TRACE_PROBE(n) \ |
45 | (offsetof(struct trace_probe, args) + \ | |
eca0d916 | 46 | (sizeof(struct probe_arg) * (n))) |
a82378d8 | 47 | |
93ccae7a | 48 | |
db02038f | 49 | static __kprobes bool trace_probe_is_return(struct trace_probe *tp) |
413d37d1 | 50 | { |
4a846b44 | 51 | return tp->rp.handler != NULL; |
413d37d1 MH |
52 | } |
53 | ||
7143f168 | 54 | static __kprobes const char *trace_probe_symbol(struct trace_probe *tp) |
413d37d1 MH |
55 | { |
56 | return tp->symbol ? tp->symbol : "unknown"; | |
57 | } | |
58 | ||
61424318 MH |
59 | static __kprobes unsigned long trace_probe_offset(struct trace_probe *tp) |
60 | { | |
61 | return tp->rp.kp.offset; | |
62 | } | |
63 | ||
64 | static __kprobes bool trace_probe_is_enabled(struct trace_probe *tp) | |
65 | { | |
66 | return !!(tp->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE)); | |
67 | } | |
68 | ||
69 | static __kprobes bool trace_probe_is_registered(struct trace_probe *tp) | |
70 | { | |
71 | return !!(tp->flags & TP_FLAG_REGISTERED); | |
72 | } | |
73 | ||
74 | static __kprobes bool trace_probe_has_gone(struct trace_probe *tp) | |
75 | { | |
76 | return !!(kprobe_gone(&tp->rp.kp)); | |
77 | } | |
78 | ||
79 | static __kprobes bool trace_probe_within_module(struct trace_probe *tp, | |
80 | struct module *mod) | |
81 | { | |
82 | int len = strlen(mod->name); | |
83 | const char *name = trace_probe_symbol(tp); | |
84 | return strncmp(mod->name, name, len) == 0 && name[len] == ':'; | |
85 | } | |
86 | ||
87 | static __kprobes bool trace_probe_is_on_module(struct trace_probe *tp) | |
88 | { | |
89 | return !!strchr(trace_probe_symbol(tp), ':'); | |
90 | } | |
91 | ||
413d37d1 MH |
92 | static int register_probe_event(struct trace_probe *tp); |
93 | static void unregister_probe_event(struct trace_probe *tp); | |
94 | ||
95 | static DEFINE_MUTEX(probe_lock); | |
96 | static LIST_HEAD(probe_list); | |
97 | ||
50d78056 MH |
98 | static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs); |
99 | static int kretprobe_dispatcher(struct kretprobe_instance *ri, | |
100 | struct pt_regs *regs); | |
101 | ||
4a846b44 MH |
102 | /* |
103 | * Allocate new trace_probe and initialize it (including kprobes). | |
104 | */ | |
f52487e9 MH |
105 | static struct trace_probe *alloc_trace_probe(const char *group, |
106 | const char *event, | |
4a846b44 MH |
107 | void *addr, |
108 | const char *symbol, | |
109 | unsigned long offs, | |
3a6b7666 | 110 | int nargs, bool is_return) |
413d37d1 MH |
111 | { |
112 | struct trace_probe *tp; | |
6f3cf440 | 113 | int ret = -ENOMEM; |
413d37d1 | 114 | |
a82378d8 | 115 | tp = kzalloc(SIZEOF_TRACE_PROBE(nargs), GFP_KERNEL); |
413d37d1 | 116 | if (!tp) |
6f3cf440 | 117 | return ERR_PTR(ret); |
413d37d1 MH |
118 | |
119 | if (symbol) { | |
120 | tp->symbol = kstrdup(symbol, GFP_KERNEL); | |
121 | if (!tp->symbol) | |
122 | goto error; | |
4a846b44 MH |
123 | tp->rp.kp.symbol_name = tp->symbol; |
124 | tp->rp.kp.offset = offs; | |
125 | } else | |
126 | tp->rp.kp.addr = addr; | |
127 | ||
128 | if (is_return) | |
50d78056 | 129 | tp->rp.handler = kretprobe_dispatcher; |
4a846b44 | 130 | else |
50d78056 | 131 | tp->rp.kp.pre_handler = kprobe_dispatcher; |
4a846b44 | 132 | |
da34634f | 133 | if (!event || !is_good_name(event)) { |
6f3cf440 | 134 | ret = -EINVAL; |
4263565d | 135 | goto error; |
6f3cf440 MH |
136 | } |
137 | ||
2239291a | 138 | tp->call.class = &tp->class; |
4263565d MH |
139 | tp->call.name = kstrdup(event, GFP_KERNEL); |
140 | if (!tp->call.name) | |
141 | goto error; | |
413d37d1 | 142 | |
da34634f | 143 | if (!group || !is_good_name(group)) { |
6f3cf440 | 144 | ret = -EINVAL; |
f52487e9 | 145 | goto error; |
6f3cf440 MH |
146 | } |
147 | ||
2239291a SR |
148 | tp->class.system = kstrdup(group, GFP_KERNEL); |
149 | if (!tp->class.system) | |
f52487e9 MH |
150 | goto error; |
151 | ||
413d37d1 MH |
152 | INIT_LIST_HEAD(&tp->list); |
153 | return tp; | |
154 | error: | |
f52487e9 | 155 | kfree(tp->call.name); |
413d37d1 MH |
156 | kfree(tp->symbol); |
157 | kfree(tp); | |
6f3cf440 | 158 | return ERR_PTR(ret); |
413d37d1 MH |
159 | } |
160 | ||
161 | static void free_trace_probe(struct trace_probe *tp) | |
162 | { | |
163 | int i; | |
164 | ||
165 | for (i = 0; i < tp->nr_args; i++) | |
8ab83f56 | 166 | traceprobe_free_probe_arg(&tp->args[i]); |
413d37d1 | 167 | |
8f082018 | 168 | kfree(tp->call.class->system); |
413d37d1 MH |
169 | kfree(tp->call.name); |
170 | kfree(tp->symbol); | |
171 | kfree(tp); | |
172 | } | |
173 | ||
7143f168 | 174 | static struct trace_probe *find_trace_probe(const char *event, |
dd004c47 | 175 | const char *group) |
413d37d1 MH |
176 | { |
177 | struct trace_probe *tp; | |
178 | ||
179 | list_for_each_entry(tp, &probe_list, list) | |
dd004c47 | 180 | if (strcmp(tp->call.name, event) == 0 && |
8f082018 | 181 | strcmp(tp->call.class->system, group) == 0) |
413d37d1 MH |
182 | return tp; |
183 | return NULL; | |
184 | } | |
185 | ||
41a7dd42 MH |
186 | static int trace_probe_nr_files(struct trace_probe *tp) |
187 | { | |
c02c7e65 | 188 | struct ftrace_event_file **file; |
41a7dd42 MH |
189 | int ret = 0; |
190 | ||
c02c7e65 MH |
191 | /* |
192 | * Since all tp->files updater is protected by probe_enable_lock, | |
193 | * we don't need to lock an rcu_read_lock. | |
194 | */ | |
195 | file = rcu_dereference_raw(tp->files); | |
41a7dd42 MH |
196 | if (file) |
197 | while (*(file++)) | |
198 | ret++; | |
199 | ||
200 | return ret; | |
201 | } | |
202 | ||
203 | static DEFINE_MUTEX(probe_enable_lock); | |
204 | ||
205 | /* | |
206 | * Enable trace_probe | |
207 | * if the file is NULL, enable "perf" handler, or enable "trace" handler. | |
208 | */ | |
209 | static int | |
210 | enable_trace_probe(struct trace_probe *tp, struct ftrace_event_file *file) | |
1538f888 MH |
211 | { |
212 | int ret = 0; | |
213 | ||
41a7dd42 MH |
214 | mutex_lock(&probe_enable_lock); |
215 | ||
216 | if (file) { | |
c02c7e65 | 217 | struct ftrace_event_file **new, **old; |
41a7dd42 MH |
218 | int n = trace_probe_nr_files(tp); |
219 | ||
c02c7e65 | 220 | old = rcu_dereference_raw(tp->files); |
41a7dd42 MH |
221 | /* 1 is for new one and 1 is for stopper */ |
222 | new = kzalloc((n + 2) * sizeof(struct ftrace_event_file *), | |
223 | GFP_KERNEL); | |
224 | if (!new) { | |
225 | ret = -ENOMEM; | |
226 | goto out_unlock; | |
227 | } | |
228 | memcpy(new, old, n * sizeof(struct ftrace_event_file *)); | |
229 | new[n] = file; | |
230 | /* The last one keeps a NULL */ | |
231 | ||
232 | rcu_assign_pointer(tp->files, new); | |
233 | tp->flags |= TP_FLAG_TRACE; | |
234 | ||
235 | if (old) { | |
236 | /* Make sure the probe is done with old files */ | |
237 | synchronize_sched(); | |
238 | kfree(old); | |
239 | } | |
240 | } else | |
241 | tp->flags |= TP_FLAG_PROFILE; | |
242 | ||
61424318 MH |
243 | if (trace_probe_is_enabled(tp) && trace_probe_is_registered(tp) && |
244 | !trace_probe_has_gone(tp)) { | |
1538f888 MH |
245 | if (trace_probe_is_return(tp)) |
246 | ret = enable_kretprobe(&tp->rp); | |
247 | else | |
248 | ret = enable_kprobe(&tp->rp.kp); | |
249 | } | |
250 | ||
41a7dd42 MH |
251 | out_unlock: |
252 | mutex_unlock(&probe_enable_lock); | |
253 | ||
1538f888 MH |
254 | return ret; |
255 | } | |
256 | ||
41a7dd42 MH |
257 | static int |
258 | trace_probe_file_index(struct trace_probe *tp, struct ftrace_event_file *file) | |
259 | { | |
c02c7e65 | 260 | struct ftrace_event_file **files; |
41a7dd42 MH |
261 | int i; |
262 | ||
c02c7e65 MH |
263 | /* |
264 | * Since all tp->files updater is protected by probe_enable_lock, | |
265 | * we don't need to lock an rcu_read_lock. | |
266 | */ | |
267 | files = rcu_dereference_raw(tp->files); | |
268 | if (files) { | |
269 | for (i = 0; files[i]; i++) | |
270 | if (files[i] == file) | |
41a7dd42 MH |
271 | return i; |
272 | } | |
273 | ||
274 | return -1; | |
275 | } | |
276 | ||
277 | /* | |
278 | * Disable trace_probe | |
279 | * if the file is NULL, disable "perf" handler, or disable "trace" handler. | |
280 | */ | |
281 | static int | |
282 | disable_trace_probe(struct trace_probe *tp, struct ftrace_event_file *file) | |
1538f888 | 283 | { |
41a7dd42 MH |
284 | int ret = 0; |
285 | ||
286 | mutex_lock(&probe_enable_lock); | |
287 | ||
288 | if (file) { | |
c02c7e65 | 289 | struct ftrace_event_file **new, **old; |
41a7dd42 MH |
290 | int n = trace_probe_nr_files(tp); |
291 | int i, j; | |
292 | ||
c02c7e65 | 293 | old = rcu_dereference_raw(tp->files); |
41a7dd42 MH |
294 | if (n == 0 || trace_probe_file_index(tp, file) < 0) { |
295 | ret = -EINVAL; | |
296 | goto out_unlock; | |
297 | } | |
298 | ||
299 | if (n == 1) { /* Remove the last file */ | |
300 | tp->flags &= ~TP_FLAG_TRACE; | |
301 | new = NULL; | |
302 | } else { | |
303 | new = kzalloc(n * sizeof(struct ftrace_event_file *), | |
304 | GFP_KERNEL); | |
305 | if (!new) { | |
306 | ret = -ENOMEM; | |
307 | goto out_unlock; | |
308 | } | |
309 | ||
310 | /* This copy & check loop copies the NULL stopper too */ | |
311 | for (i = 0, j = 0; j < n && i < n + 1; i++) | |
312 | if (old[i] != file) | |
313 | new[j++] = old[i]; | |
314 | } | |
315 | ||
316 | rcu_assign_pointer(tp->files, new); | |
317 | ||
318 | /* Make sure the probe is done with old files */ | |
319 | synchronize_sched(); | |
320 | kfree(old); | |
321 | } else | |
322 | tp->flags &= ~TP_FLAG_PROFILE; | |
323 | ||
61424318 | 324 | if (!trace_probe_is_enabled(tp) && trace_probe_is_registered(tp)) { |
1538f888 MH |
325 | if (trace_probe_is_return(tp)) |
326 | disable_kretprobe(&tp->rp); | |
327 | else | |
328 | disable_kprobe(&tp->rp.kp); | |
329 | } | |
41a7dd42 MH |
330 | |
331 | out_unlock: | |
332 | mutex_unlock(&probe_enable_lock); | |
333 | ||
334 | return ret; | |
1538f888 MH |
335 | } |
336 | ||
61424318 MH |
337 | /* Internal register function - just handle k*probes and flags */ |
338 | static int __register_trace_probe(struct trace_probe *tp) | |
413d37d1 | 339 | { |
7f6878a3 | 340 | int i, ret; |
61424318 MH |
341 | |
342 | if (trace_probe_is_registered(tp)) | |
343 | return -EINVAL; | |
344 | ||
7f6878a3 | 345 | for (i = 0; i < tp->nr_args; i++) |
8ab83f56 | 346 | traceprobe_update_arg(&tp->args[i]); |
7f6878a3 | 347 | |
61424318 MH |
348 | /* Set/clear disabled flag according to tp->flag */ |
349 | if (trace_probe_is_enabled(tp)) | |
350 | tp->rp.kp.flags &= ~KPROBE_FLAG_DISABLED; | |
351 | else | |
352 | tp->rp.kp.flags |= KPROBE_FLAG_DISABLED; | |
353 | ||
7143f168 | 354 | if (trace_probe_is_return(tp)) |
61424318 | 355 | ret = register_kretprobe(&tp->rp); |
413d37d1 | 356 | else |
61424318 MH |
357 | ret = register_kprobe(&tp->rp.kp); |
358 | ||
359 | if (ret == 0) | |
360 | tp->flags |= TP_FLAG_REGISTERED; | |
361 | else { | |
362 | pr_warning("Could not insert probe at %s+%lu: %d\n", | |
363 | trace_probe_symbol(tp), trace_probe_offset(tp), ret); | |
364 | if (ret == -ENOENT && trace_probe_is_on_module(tp)) { | |
365 | pr_warning("This probe might be able to register after" | |
366 | "target module is loaded. Continue.\n"); | |
367 | ret = 0; | |
368 | } else if (ret == -EILSEQ) { | |
369 | pr_warning("Probing address(0x%p) is not an " | |
370 | "instruction boundary.\n", | |
371 | tp->rp.kp.addr); | |
372 | ret = -EINVAL; | |
373 | } | |
374 | } | |
375 | ||
376 | return ret; | |
377 | } | |
378 | ||
379 | /* Internal unregister function - just handle k*probes and flags */ | |
380 | static void __unregister_trace_probe(struct trace_probe *tp) | |
381 | { | |
382 | if (trace_probe_is_registered(tp)) { | |
383 | if (trace_probe_is_return(tp)) | |
384 | unregister_kretprobe(&tp->rp); | |
385 | else | |
386 | unregister_kprobe(&tp->rp.kp); | |
387 | tp->flags &= ~TP_FLAG_REGISTERED; | |
388 | /* Cleanup kprobe for reuse */ | |
389 | if (tp->rp.kp.symbol_name) | |
390 | tp->rp.kp.addr = NULL; | |
391 | } | |
392 | } | |
393 | ||
394 | /* Unregister a trace_probe and probe_event: call with locking probe_lock */ | |
02ca1521 | 395 | static int unregister_trace_probe(struct trace_probe *tp) |
61424318 | 396 | { |
02ca1521 MH |
397 | /* Enabled event can not be unregistered */ |
398 | if (trace_probe_is_enabled(tp)) | |
399 | return -EBUSY; | |
400 | ||
61424318 | 401 | __unregister_trace_probe(tp); |
413d37d1 | 402 | list_del(&tp->list); |
2d5e067e | 403 | unregister_probe_event(tp); |
02ca1521 MH |
404 | |
405 | return 0; | |
413d37d1 MH |
406 | } |
407 | ||
408 | /* Register a trace_probe and probe_event */ | |
409 | static int register_trace_probe(struct trace_probe *tp) | |
410 | { | |
411 | struct trace_probe *old_tp; | |
412 | int ret; | |
413 | ||
414 | mutex_lock(&probe_lock); | |
415 | ||
61424318 | 416 | /* Delete old (same name) event if exist */ |
7143f168 | 417 | old_tp = find_trace_probe(tp->call.name, tp->call.class->system); |
2d5e067e | 418 | if (old_tp) { |
02ca1521 MH |
419 | ret = unregister_trace_probe(old_tp); |
420 | if (ret < 0) | |
421 | goto end; | |
2d5e067e MH |
422 | free_trace_probe(old_tp); |
423 | } | |
61424318 MH |
424 | |
425 | /* Register new event */ | |
2d5e067e MH |
426 | ret = register_probe_event(tp); |
427 | if (ret) { | |
426d3107 | 428 | pr_warning("Failed to register probe event(%d)\n", ret); |
2d5e067e MH |
429 | goto end; |
430 | } | |
431 | ||
61424318 MH |
432 | /* Register k*probe */ |
433 | ret = __register_trace_probe(tp); | |
434 | if (ret < 0) | |
2d5e067e | 435 | unregister_probe_event(tp); |
61424318 | 436 | else |
2d5e067e | 437 | list_add_tail(&tp->list, &probe_list); |
61424318 | 438 | |
413d37d1 MH |
439 | end: |
440 | mutex_unlock(&probe_lock); | |
441 | return ret; | |
442 | } | |
443 | ||
61424318 MH |
444 | /* Module notifier call back, checking event on the module */ |
445 | static int trace_probe_module_callback(struct notifier_block *nb, | |
446 | unsigned long val, void *data) | |
447 | { | |
448 | struct module *mod = data; | |
449 | struct trace_probe *tp; | |
450 | int ret; | |
451 | ||
452 | if (val != MODULE_STATE_COMING) | |
453 | return NOTIFY_DONE; | |
454 | ||
455 | /* Update probes on coming module */ | |
456 | mutex_lock(&probe_lock); | |
457 | list_for_each_entry(tp, &probe_list, list) { | |
458 | if (trace_probe_within_module(tp, mod)) { | |
02ca1521 | 459 | /* Don't need to check busy - this should have gone. */ |
61424318 MH |
460 | __unregister_trace_probe(tp); |
461 | ret = __register_trace_probe(tp); | |
462 | if (ret) | |
463 | pr_warning("Failed to re-register probe %s on" | |
464 | "%s: %d\n", | |
465 | tp->call.name, mod->name, ret); | |
466 | } | |
467 | } | |
468 | mutex_unlock(&probe_lock); | |
469 | ||
470 | return NOTIFY_DONE; | |
471 | } | |
472 | ||
473 | static struct notifier_block trace_probe_module_nb = { | |
474 | .notifier_call = trace_probe_module_callback, | |
475 | .priority = 1 /* Invoked after kprobe module callback */ | |
476 | }; | |
477 | ||
413d37d1 MH |
478 | static int create_trace_probe(int argc, char **argv) |
479 | { | |
480 | /* | |
481 | * Argument syntax: | |
61424318 MH |
482 | * - Add kprobe: p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS] |
483 | * - Add kretprobe: r[:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS] | |
413d37d1 | 484 | * Fetch args: |
2e06ff63 MH |
485 | * $retval : fetch return value |
486 | * $stack : fetch stack address | |
487 | * $stackN : fetch Nth of stack (N:0-) | |
413d37d1 MH |
488 | * @ADDR : fetch memory at ADDR (ADDR should be in kernel) |
489 | * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol) | |
490 | * %REG : fetch register REG | |
93ccae7a | 491 | * Dereferencing memory fetch: |
413d37d1 | 492 | * +|-offs(ARG) : fetch memory at ARG +|- offs address. |
eca0d916 MH |
493 | * Alias name of args: |
494 | * NAME=FETCHARG : set NAME as alias of FETCHARG. | |
93ccae7a MH |
495 | * Type of args: |
496 | * FETCHARG:TYPE : use TYPE instead of unsigned long. | |
413d37d1 MH |
497 | */ |
498 | struct trace_probe *tp; | |
413d37d1 | 499 | int i, ret = 0; |
3a6b7666 | 500 | bool is_return = false, is_delete = false; |
93ccae7a | 501 | char *symbol = NULL, *event = NULL, *group = NULL; |
da34634f | 502 | char *arg; |
2fba0c88 | 503 | unsigned long offset = 0; |
413d37d1 | 504 | void *addr = NULL; |
4a846b44 | 505 | char buf[MAX_EVENT_NAME_LEN]; |
413d37d1 | 506 | |
a7c312be | 507 | /* argc must be >= 1 */ |
413d37d1 | 508 | if (argv[0][0] == 'p') |
3a6b7666 | 509 | is_return = false; |
413d37d1 | 510 | else if (argv[0][0] == 'r') |
3a6b7666 | 511 | is_return = true; |
a7c312be | 512 | else if (argv[0][0] == '-') |
3a6b7666 | 513 | is_delete = true; |
e63cc239 | 514 | else { |
a7c312be MH |
515 | pr_info("Probe definition must be started with 'p', 'r' or" |
516 | " '-'.\n"); | |
413d37d1 | 517 | return -EINVAL; |
e63cc239 | 518 | } |
413d37d1 MH |
519 | |
520 | if (argv[0][1] == ':') { | |
521 | event = &argv[0][2]; | |
f52487e9 MH |
522 | if (strchr(event, '/')) { |
523 | group = event; | |
524 | event = strchr(group, '/') + 1; | |
525 | event[-1] = '\0'; | |
526 | if (strlen(group) == 0) { | |
a5efd925 | 527 | pr_info("Group name is not specified\n"); |
f52487e9 MH |
528 | return -EINVAL; |
529 | } | |
530 | } | |
413d37d1 | 531 | if (strlen(event) == 0) { |
a5efd925 | 532 | pr_info("Event name is not specified\n"); |
413d37d1 MH |
533 | return -EINVAL; |
534 | } | |
535 | } | |
a7c312be MH |
536 | if (!group) |
537 | group = KPROBE_EVENT_SYSTEM; | |
413d37d1 | 538 | |
a7c312be MH |
539 | if (is_delete) { |
540 | if (!event) { | |
541 | pr_info("Delete command needs an event name.\n"); | |
542 | return -EINVAL; | |
543 | } | |
9da79ab8 | 544 | mutex_lock(&probe_lock); |
7143f168 | 545 | tp = find_trace_probe(event, group); |
a7c312be | 546 | if (!tp) { |
9da79ab8 | 547 | mutex_unlock(&probe_lock); |
a7c312be MH |
548 | pr_info("Event %s/%s doesn't exist.\n", group, event); |
549 | return -ENOENT; | |
550 | } | |
551 | /* delete an event */ | |
02ca1521 MH |
552 | ret = unregister_trace_probe(tp); |
553 | if (ret == 0) | |
554 | free_trace_probe(tp); | |
9da79ab8 | 555 | mutex_unlock(&probe_lock); |
02ca1521 | 556 | return ret; |
a7c312be MH |
557 | } |
558 | ||
559 | if (argc < 2) { | |
560 | pr_info("Probe point is not specified.\n"); | |
561 | return -EINVAL; | |
562 | } | |
413d37d1 | 563 | if (isdigit(argv[1][0])) { |
e63cc239 MH |
564 | if (is_return) { |
565 | pr_info("Return probe point must be a symbol.\n"); | |
413d37d1 | 566 | return -EINVAL; |
e63cc239 | 567 | } |
413d37d1 | 568 | /* an address specified */ |
bcd83ea6 | 569 | ret = kstrtoul(&argv[1][0], 0, (unsigned long *)&addr); |
e63cc239 MH |
570 | if (ret) { |
571 | pr_info("Failed to parse address.\n"); | |
413d37d1 | 572 | return ret; |
e63cc239 | 573 | } |
413d37d1 MH |
574 | } else { |
575 | /* a symbol specified */ | |
576 | symbol = argv[1]; | |
577 | /* TODO: support .init module functions */ | |
8ab83f56 | 578 | ret = traceprobe_split_symbol_offset(symbol, &offset); |
e63cc239 MH |
579 | if (ret) { |
580 | pr_info("Failed to parse symbol.\n"); | |
413d37d1 | 581 | return ret; |
e63cc239 MH |
582 | } |
583 | if (offset && is_return) { | |
584 | pr_info("Return probe must be used without offset.\n"); | |
413d37d1 | 585 | return -EINVAL; |
e63cc239 | 586 | } |
413d37d1 | 587 | } |
a82378d8 | 588 | argc -= 2; argv += 2; |
413d37d1 MH |
589 | |
590 | /* setup a probe */ | |
4263565d MH |
591 | if (!event) { |
592 | /* Make a new event name */ | |
4263565d | 593 | if (symbol) |
6f3cf440 | 594 | snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld", |
4263565d MH |
595 | is_return ? 'r' : 'p', symbol, offset); |
596 | else | |
6f3cf440 | 597 | snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p", |
4263565d | 598 | is_return ? 'r' : 'p', addr); |
4a846b44 MH |
599 | event = buf; |
600 | } | |
f52487e9 MH |
601 | tp = alloc_trace_probe(group, event, addr, symbol, offset, argc, |
602 | is_return); | |
e63cc239 MH |
603 | if (IS_ERR(tp)) { |
604 | pr_info("Failed to allocate trace_probe.(%d)\n", | |
605 | (int)PTR_ERR(tp)); | |
413d37d1 | 606 | return PTR_ERR(tp); |
e63cc239 | 607 | } |
413d37d1 | 608 | |
413d37d1 | 609 | /* parse arguments */ |
a82378d8 MH |
610 | ret = 0; |
611 | for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { | |
61a52736 MH |
612 | /* Increment count for freeing args in error case */ |
613 | tp->nr_args++; | |
614 | ||
eca0d916 MH |
615 | /* Parse argument name */ |
616 | arg = strchr(argv[i], '='); | |
aba91595 | 617 | if (arg) { |
eca0d916 | 618 | *arg++ = '\0'; |
aba91595 MH |
619 | tp->args[i].name = kstrdup(argv[i], GFP_KERNEL); |
620 | } else { | |
eca0d916 | 621 | arg = argv[i]; |
aba91595 MH |
622 | /* If argument name is omitted, set "argN" */ |
623 | snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1); | |
624 | tp->args[i].name = kstrdup(buf, GFP_KERNEL); | |
625 | } | |
a703d946 | 626 | |
ba8665d7 | 627 | if (!tp->args[i].name) { |
aba91595 | 628 | pr_info("Failed to allocate argument[%d] name.\n", i); |
ba8665d7 | 629 | ret = -ENOMEM; |
413d37d1 MH |
630 | goto error; |
631 | } | |
da34634f MH |
632 | |
633 | if (!is_good_name(tp->args[i].name)) { | |
634 | pr_info("Invalid argument[%d] name: %s\n", | |
635 | i, tp->args[i].name); | |
636 | ret = -EINVAL; | |
637 | goto error; | |
638 | } | |
93ccae7a | 639 | |
8ab83f56 SD |
640 | if (traceprobe_conflict_field_name(tp->args[i].name, |
641 | tp->args, i)) { | |
aba91595 | 642 | pr_info("Argument[%d] name '%s' conflicts with " |
93ccae7a MH |
643 | "another field.\n", i, argv[i]); |
644 | ret = -EINVAL; | |
645 | goto error; | |
646 | } | |
ba8665d7 MH |
647 | |
648 | /* Parse fetch argument */ | |
8ab83f56 | 649 | ret = traceprobe_parse_probe_arg(arg, &tp->size, &tp->args[i], |
f3f096cf | 650 | is_return, true); |
e63cc239 | 651 | if (ret) { |
aba91595 | 652 | pr_info("Parse error at argument[%d]. (%d)\n", i, ret); |
413d37d1 | 653 | goto error; |
e63cc239 | 654 | } |
413d37d1 | 655 | } |
413d37d1 MH |
656 | |
657 | ret = register_trace_probe(tp); | |
658 | if (ret) | |
659 | goto error; | |
660 | return 0; | |
661 | ||
662 | error: | |
663 | free_trace_probe(tp); | |
664 | return ret; | |
665 | } | |
666 | ||
02ca1521 | 667 | static int release_all_trace_probes(void) |
413d37d1 MH |
668 | { |
669 | struct trace_probe *tp; | |
02ca1521 | 670 | int ret = 0; |
413d37d1 MH |
671 | |
672 | mutex_lock(&probe_lock); | |
02ca1521 MH |
673 | /* Ensure no probe is in use. */ |
674 | list_for_each_entry(tp, &probe_list, list) | |
675 | if (trace_probe_is_enabled(tp)) { | |
676 | ret = -EBUSY; | |
677 | goto end; | |
678 | } | |
413d37d1 MH |
679 | /* TODO: Use batch unregistration */ |
680 | while (!list_empty(&probe_list)) { | |
681 | tp = list_entry(probe_list.next, struct trace_probe, list); | |
682 | unregister_trace_probe(tp); | |
683 | free_trace_probe(tp); | |
684 | } | |
02ca1521 MH |
685 | |
686 | end: | |
413d37d1 | 687 | mutex_unlock(&probe_lock); |
02ca1521 MH |
688 | |
689 | return ret; | |
413d37d1 MH |
690 | } |
691 | ||
413d37d1 MH |
692 | /* Probes listing interfaces */ |
693 | static void *probes_seq_start(struct seq_file *m, loff_t *pos) | |
694 | { | |
695 | mutex_lock(&probe_lock); | |
696 | return seq_list_start(&probe_list, *pos); | |
697 | } | |
698 | ||
699 | static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos) | |
700 | { | |
701 | return seq_list_next(v, &probe_list, pos); | |
702 | } | |
703 | ||
704 | static void probes_seq_stop(struct seq_file *m, void *v) | |
705 | { | |
706 | mutex_unlock(&probe_lock); | |
707 | } | |
708 | ||
709 | static int probes_seq_show(struct seq_file *m, void *v) | |
710 | { | |
711 | struct trace_probe *tp = v; | |
93ccae7a | 712 | int i; |
413d37d1 | 713 | |
7143f168 | 714 | seq_printf(m, "%c", trace_probe_is_return(tp) ? 'r' : 'p'); |
8f082018 | 715 | seq_printf(m, ":%s/%s", tp->call.class->system, tp->call.name); |
413d37d1 | 716 | |
52a11f35 LJ |
717 | if (!tp->symbol) |
718 | seq_printf(m, " 0x%p", tp->rp.kp.addr); | |
719 | else if (tp->rp.kp.offset) | |
7143f168 MH |
720 | seq_printf(m, " %s+%u", trace_probe_symbol(tp), |
721 | tp->rp.kp.offset); | |
413d37d1 | 722 | else |
7143f168 | 723 | seq_printf(m, " %s", trace_probe_symbol(tp)); |
413d37d1 | 724 | |
93ccae7a MH |
725 | for (i = 0; i < tp->nr_args; i++) |
726 | seq_printf(m, " %s=%s", tp->args[i].name, tp->args[i].comm); | |
413d37d1 | 727 | seq_printf(m, "\n"); |
93ccae7a | 728 | |
413d37d1 MH |
729 | return 0; |
730 | } | |
731 | ||
732 | static const struct seq_operations probes_seq_op = { | |
733 | .start = probes_seq_start, | |
734 | .next = probes_seq_next, | |
735 | .stop = probes_seq_stop, | |
736 | .show = probes_seq_show | |
737 | }; | |
738 | ||
739 | static int probes_open(struct inode *inode, struct file *file) | |
740 | { | |
02ca1521 MH |
741 | int ret; |
742 | ||
743 | if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { | |
744 | ret = release_all_trace_probes(); | |
745 | if (ret < 0) | |
746 | return ret; | |
747 | } | |
413d37d1 MH |
748 | |
749 | return seq_open(file, &probes_seq_op); | |
750 | } | |
751 | ||
413d37d1 MH |
752 | static ssize_t probes_write(struct file *file, const char __user *buffer, |
753 | size_t count, loff_t *ppos) | |
754 | { | |
8ab83f56 SD |
755 | return traceprobe_probes_write(file, buffer, count, ppos, |
756 | create_trace_probe); | |
413d37d1 MH |
757 | } |
758 | ||
759 | static const struct file_operations kprobe_events_ops = { | |
760 | .owner = THIS_MODULE, | |
761 | .open = probes_open, | |
762 | .read = seq_read, | |
763 | .llseek = seq_lseek, | |
764 | .release = seq_release, | |
765 | .write = probes_write, | |
766 | }; | |
767 | ||
cd7e7bd5 MH |
768 | /* Probes profiling interfaces */ |
769 | static int probes_profile_seq_show(struct seq_file *m, void *v) | |
770 | { | |
771 | struct trace_probe *tp = v; | |
772 | ||
773 | seq_printf(m, " %-44s %15lu %15lu\n", tp->call.name, tp->nhit, | |
4a846b44 | 774 | tp->rp.kp.nmissed); |
cd7e7bd5 MH |
775 | |
776 | return 0; | |
777 | } | |
778 | ||
779 | static const struct seq_operations profile_seq_op = { | |
780 | .start = probes_seq_start, | |
781 | .next = probes_seq_next, | |
782 | .stop = probes_seq_stop, | |
783 | .show = probes_profile_seq_show | |
784 | }; | |
785 | ||
786 | static int profile_open(struct inode *inode, struct file *file) | |
787 | { | |
788 | return seq_open(file, &profile_seq_op); | |
789 | } | |
790 | ||
791 | static const struct file_operations kprobe_profile_ops = { | |
792 | .owner = THIS_MODULE, | |
793 | .open = profile_open, | |
794 | .read = seq_read, | |
795 | .llseek = seq_lseek, | |
796 | .release = seq_release, | |
797 | }; | |
798 | ||
e09c8614 MH |
799 | /* Sum up total data length for dynamic arraies (strings) */ |
800 | static __kprobes int __get_data_size(struct trace_probe *tp, | |
801 | struct pt_regs *regs) | |
802 | { | |
803 | int i, ret = 0; | |
804 | u32 len; | |
805 | ||
806 | for (i = 0; i < tp->nr_args; i++) | |
807 | if (unlikely(tp->args[i].fetch_size.fn)) { | |
808 | call_fetch(&tp->args[i].fetch_size, regs, &len); | |
809 | ret += len; | |
810 | } | |
811 | ||
812 | return ret; | |
813 | } | |
814 | ||
815 | /* Store the value of each argument */ | |
816 | static __kprobes void store_trace_args(int ent_size, struct trace_probe *tp, | |
817 | struct pt_regs *regs, | |
818 | u8 *data, int maxlen) | |
819 | { | |
820 | int i; | |
821 | u32 end = tp->size; | |
822 | u32 *dl; /* Data (relative) location */ | |
823 | ||
824 | for (i = 0; i < tp->nr_args; i++) { | |
825 | if (unlikely(tp->args[i].fetch_size.fn)) { | |
826 | /* | |
827 | * First, we set the relative location and | |
828 | * maximum data length to *dl | |
829 | */ | |
830 | dl = (u32 *)(data + tp->args[i].offset); | |
831 | *dl = make_data_rloc(maxlen, end - tp->args[i].offset); | |
832 | /* Then try to fetch string or dynamic array data */ | |
833 | call_fetch(&tp->args[i].fetch, regs, dl); | |
834 | /* Reduce maximum length */ | |
835 | end += get_rloc_len(*dl); | |
836 | maxlen -= get_rloc_len(*dl); | |
837 | /* Trick here, convert data_rloc to data_loc */ | |
838 | *dl = convert_rloc_to_loc(*dl, | |
839 | ent_size + tp->args[i].offset); | |
840 | } else | |
841 | /* Just fetching data normally */ | |
842 | call_fetch(&tp->args[i].fetch, regs, | |
843 | data + tp->args[i].offset); | |
844 | } | |
845 | } | |
846 | ||
413d37d1 | 847 | /* Kprobe handler */ |
2b106aab | 848 | static __kprobes void |
41a7dd42 MH |
849 | __kprobe_trace_func(struct trace_probe *tp, struct pt_regs *regs, |
850 | struct ftrace_event_file *ftrace_file) | |
413d37d1 | 851 | { |
93ccae7a | 852 | struct kprobe_trace_entry_head *entry; |
413d37d1 | 853 | struct ring_buffer_event *event; |
8f8ffe24 | 854 | struct ring_buffer *buffer; |
e09c8614 | 855 | int size, dsize, pc; |
413d37d1 | 856 | unsigned long irq_flags; |
4263565d | 857 | struct ftrace_event_call *call = &tp->call; |
413d37d1 | 858 | |
41a7dd42 MH |
859 | WARN_ON(call != ftrace_file->event_call); |
860 | ||
b8820084 MH |
861 | if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags)) |
862 | return; | |
863 | ||
413d37d1 MH |
864 | local_save_flags(irq_flags); |
865 | pc = preempt_count(); | |
866 | ||
e09c8614 MH |
867 | dsize = __get_data_size(tp, regs); |
868 | size = sizeof(*entry) + tp->size + dsize; | |
413d37d1 | 869 | |
41a7dd42 MH |
870 | event = trace_event_buffer_lock_reserve(&buffer, ftrace_file, |
871 | call->event.type, | |
872 | size, irq_flags, pc); | |
413d37d1 | 873 | if (!event) |
1e12a4a7 | 874 | return; |
413d37d1 MH |
875 | |
876 | entry = ring_buffer_event_data(event); | |
2b106aab | 877 | entry->ip = (unsigned long)tp->rp.kp.addr; |
e09c8614 | 878 | store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize); |
413d37d1 | 879 | |
8f8ffe24 | 880 | if (!filter_current_check_discard(buffer, call, entry, event)) |
0d5c6e1c SR |
881 | trace_buffer_unlock_commit_regs(buffer, event, |
882 | irq_flags, pc, regs); | |
413d37d1 MH |
883 | } |
884 | ||
41a7dd42 MH |
885 | static __kprobes void |
886 | kprobe_trace_func(struct trace_probe *tp, struct pt_regs *regs) | |
887 | { | |
c02c7e65 MH |
888 | /* |
889 | * Note: preempt is already disabled around the kprobe handler. | |
890 | * However, we still need an smp_read_barrier_depends() corresponding | |
891 | * to smp_wmb() in rcu_assign_pointer() to access the pointer. | |
892 | */ | |
893 | struct ftrace_event_file **file = rcu_dereference_raw(tp->files); | |
894 | ||
895 | if (unlikely(!file)) | |
896 | return; | |
41a7dd42 | 897 | |
41a7dd42 MH |
898 | while (*file) { |
899 | __kprobe_trace_func(tp, regs, *file); | |
900 | file++; | |
901 | } | |
902 | } | |
903 | ||
413d37d1 | 904 | /* Kretprobe handler */ |
2b106aab | 905 | static __kprobes void |
41a7dd42 MH |
906 | __kretprobe_trace_func(struct trace_probe *tp, struct kretprobe_instance *ri, |
907 | struct pt_regs *regs, | |
908 | struct ftrace_event_file *ftrace_file) | |
413d37d1 | 909 | { |
93ccae7a | 910 | struct kretprobe_trace_entry_head *entry; |
413d37d1 | 911 | struct ring_buffer_event *event; |
8f8ffe24 | 912 | struct ring_buffer *buffer; |
e09c8614 | 913 | int size, pc, dsize; |
413d37d1 | 914 | unsigned long irq_flags; |
4263565d | 915 | struct ftrace_event_call *call = &tp->call; |
413d37d1 | 916 | |
41a7dd42 MH |
917 | WARN_ON(call != ftrace_file->event_call); |
918 | ||
b8820084 MH |
919 | if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags)) |
920 | return; | |
921 | ||
413d37d1 MH |
922 | local_save_flags(irq_flags); |
923 | pc = preempt_count(); | |
924 | ||
e09c8614 MH |
925 | dsize = __get_data_size(tp, regs); |
926 | size = sizeof(*entry) + tp->size + dsize; | |
413d37d1 | 927 | |
41a7dd42 MH |
928 | event = trace_event_buffer_lock_reserve(&buffer, ftrace_file, |
929 | call->event.type, | |
930 | size, irq_flags, pc); | |
413d37d1 | 931 | if (!event) |
1e12a4a7 | 932 | return; |
413d37d1 MH |
933 | |
934 | entry = ring_buffer_event_data(event); | |
4a846b44 | 935 | entry->func = (unsigned long)tp->rp.kp.addr; |
413d37d1 | 936 | entry->ret_ip = (unsigned long)ri->ret_addr; |
e09c8614 | 937 | store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize); |
413d37d1 | 938 | |
8f8ffe24 | 939 | if (!filter_current_check_discard(buffer, call, entry, event)) |
0d5c6e1c SR |
940 | trace_buffer_unlock_commit_regs(buffer, event, |
941 | irq_flags, pc, regs); | |
413d37d1 MH |
942 | } |
943 | ||
41a7dd42 MH |
944 | static __kprobes void |
945 | kretprobe_trace_func(struct trace_probe *tp, struct kretprobe_instance *ri, | |
946 | struct pt_regs *regs) | |
947 | { | |
c02c7e65 MH |
948 | /* |
949 | * Note: preempt is already disabled around the kprobe handler. | |
950 | * However, we still need an smp_read_barrier_depends() corresponding | |
951 | * to smp_wmb() in rcu_assign_pointer() to access the pointer. | |
952 | */ | |
953 | struct ftrace_event_file **file = rcu_dereference_raw(tp->files); | |
954 | ||
955 | if (unlikely(!file)) | |
956 | return; | |
41a7dd42 | 957 | |
41a7dd42 MH |
958 | while (*file) { |
959 | __kretprobe_trace_func(tp, ri, regs, *file); | |
960 | file++; | |
961 | } | |
962 | } | |
963 | ||
413d37d1 | 964 | /* Event entry printers */ |
b62fdd97 | 965 | static enum print_line_t |
a9a57763 SR |
966 | print_kprobe_event(struct trace_iterator *iter, int flags, |
967 | struct trace_event *event) | |
413d37d1 | 968 | { |
93ccae7a | 969 | struct kprobe_trace_entry_head *field; |
413d37d1 | 970 | struct trace_seq *s = &iter->seq; |
eca0d916 | 971 | struct trace_probe *tp; |
93ccae7a | 972 | u8 *data; |
413d37d1 MH |
973 | int i; |
974 | ||
93ccae7a | 975 | field = (struct kprobe_trace_entry_head *)iter->ent; |
80decc70 | 976 | tp = container_of(event, struct trace_probe, call.event); |
413d37d1 | 977 | |
6e9f23d1 MH |
978 | if (!trace_seq_printf(s, "%s: (", tp->call.name)) |
979 | goto partial; | |
980 | ||
413d37d1 MH |
981 | if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET)) |
982 | goto partial; | |
983 | ||
6e9f23d1 | 984 | if (!trace_seq_puts(s, ")")) |
413d37d1 MH |
985 | goto partial; |
986 | ||
93ccae7a MH |
987 | data = (u8 *)&field[1]; |
988 | for (i = 0; i < tp->nr_args; i++) | |
989 | if (!tp->args[i].type->print(s, tp->args[i].name, | |
e09c8614 | 990 | data + tp->args[i].offset, field)) |
413d37d1 MH |
991 | goto partial; |
992 | ||
993 | if (!trace_seq_puts(s, "\n")) | |
994 | goto partial; | |
995 | ||
996 | return TRACE_TYPE_HANDLED; | |
997 | partial: | |
998 | return TRACE_TYPE_PARTIAL_LINE; | |
999 | } | |
1000 | ||
b62fdd97 | 1001 | static enum print_line_t |
a9a57763 SR |
1002 | print_kretprobe_event(struct trace_iterator *iter, int flags, |
1003 | struct trace_event *event) | |
413d37d1 | 1004 | { |
93ccae7a | 1005 | struct kretprobe_trace_entry_head *field; |
413d37d1 | 1006 | struct trace_seq *s = &iter->seq; |
eca0d916 | 1007 | struct trace_probe *tp; |
93ccae7a | 1008 | u8 *data; |
413d37d1 MH |
1009 | int i; |
1010 | ||
93ccae7a | 1011 | field = (struct kretprobe_trace_entry_head *)iter->ent; |
80decc70 | 1012 | tp = container_of(event, struct trace_probe, call.event); |
413d37d1 | 1013 | |
6e9f23d1 MH |
1014 | if (!trace_seq_printf(s, "%s: (", tp->call.name)) |
1015 | goto partial; | |
1016 | ||
413d37d1 MH |
1017 | if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET)) |
1018 | goto partial; | |
1019 | ||
1020 | if (!trace_seq_puts(s, " <- ")) | |
1021 | goto partial; | |
1022 | ||
1023 | if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET)) | |
1024 | goto partial; | |
1025 | ||
6e9f23d1 | 1026 | if (!trace_seq_puts(s, ")")) |
413d37d1 MH |
1027 | goto partial; |
1028 | ||
93ccae7a MH |
1029 | data = (u8 *)&field[1]; |
1030 | for (i = 0; i < tp->nr_args; i++) | |
1031 | if (!tp->args[i].type->print(s, tp->args[i].name, | |
e09c8614 | 1032 | data + tp->args[i].offset, field)) |
413d37d1 MH |
1033 | goto partial; |
1034 | ||
1035 | if (!trace_seq_puts(s, "\n")) | |
1036 | goto partial; | |
1037 | ||
1038 | return TRACE_TYPE_HANDLED; | |
1039 | partial: | |
1040 | return TRACE_TYPE_PARTIAL_LINE; | |
1041 | } | |
1042 | ||
413d37d1 MH |
1043 | |
1044 | static int kprobe_event_define_fields(struct ftrace_event_call *event_call) | |
1045 | { | |
1046 | int ret, i; | |
93ccae7a | 1047 | struct kprobe_trace_entry_head field; |
413d37d1 MH |
1048 | struct trace_probe *tp = (struct trace_probe *)event_call->data; |
1049 | ||
a703d946 | 1050 | DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0); |
eca0d916 | 1051 | /* Set argument names as fields */ |
93ccae7a | 1052 | for (i = 0; i < tp->nr_args; i++) { |
e09c8614 | 1053 | ret = trace_define_field(event_call, tp->args[i].type->fmttype, |
93ccae7a MH |
1054 | tp->args[i].name, |
1055 | sizeof(field) + tp->args[i].offset, | |
1056 | tp->args[i].type->size, | |
1057 | tp->args[i].type->is_signed, | |
1058 | FILTER_OTHER); | |
1059 | if (ret) | |
1060 | return ret; | |
1061 | } | |
413d37d1 MH |
1062 | return 0; |
1063 | } | |
1064 | ||
1065 | static int kretprobe_event_define_fields(struct ftrace_event_call *event_call) | |
1066 | { | |
1067 | int ret, i; | |
93ccae7a | 1068 | struct kretprobe_trace_entry_head field; |
413d37d1 MH |
1069 | struct trace_probe *tp = (struct trace_probe *)event_call->data; |
1070 | ||
a703d946 MH |
1071 | DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0); |
1072 | DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0); | |
eca0d916 | 1073 | /* Set argument names as fields */ |
93ccae7a | 1074 | for (i = 0; i < tp->nr_args; i++) { |
e09c8614 | 1075 | ret = trace_define_field(event_call, tp->args[i].type->fmttype, |
93ccae7a MH |
1076 | tp->args[i].name, |
1077 | sizeof(field) + tp->args[i].offset, | |
1078 | tp->args[i].type->size, | |
1079 | tp->args[i].type->is_signed, | |
1080 | FILTER_OTHER); | |
1081 | if (ret) | |
1082 | return ret; | |
1083 | } | |
413d37d1 MH |
1084 | return 0; |
1085 | } | |
1086 | ||
a342a028 LJ |
1087 | static int __set_print_fmt(struct trace_probe *tp, char *buf, int len) |
1088 | { | |
1089 | int i; | |
1090 | int pos = 0; | |
1091 | ||
1092 | const char *fmt, *arg; | |
1093 | ||
7143f168 | 1094 | if (!trace_probe_is_return(tp)) { |
a342a028 LJ |
1095 | fmt = "(%lx)"; |
1096 | arg = "REC->" FIELD_STRING_IP; | |
1097 | } else { | |
1098 | fmt = "(%lx <- %lx)"; | |
1099 | arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP; | |
1100 | } | |
1101 | ||
1102 | /* When len=0, we just calculate the needed length */ | |
1103 | #define LEN_OR_ZERO (len ? len - pos : 0) | |
1104 | ||
1105 | pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt); | |
1106 | ||
1107 | for (i = 0; i < tp->nr_args; i++) { | |
93ccae7a MH |
1108 | pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%s", |
1109 | tp->args[i].name, tp->args[i].type->fmt); | |
a342a028 LJ |
1110 | } |
1111 | ||
1112 | pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg); | |
1113 | ||
1114 | for (i = 0; i < tp->nr_args; i++) { | |
e09c8614 MH |
1115 | if (strcmp(tp->args[i].type->name, "string") == 0) |
1116 | pos += snprintf(buf + pos, LEN_OR_ZERO, | |
1117 | ", __get_str(%s)", | |
1118 | tp->args[i].name); | |
1119 | else | |
1120 | pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s", | |
1121 | tp->args[i].name); | |
a342a028 LJ |
1122 | } |
1123 | ||
1124 | #undef LEN_OR_ZERO | |
1125 | ||
1126 | /* return the length of print_fmt */ | |
1127 | return pos; | |
1128 | } | |
1129 | ||
1130 | static int set_print_fmt(struct trace_probe *tp) | |
1131 | { | |
1132 | int len; | |
1133 | char *print_fmt; | |
1134 | ||
1135 | /* First: called with 0 length to calculate the needed length */ | |
1136 | len = __set_print_fmt(tp, NULL, 0); | |
1137 | print_fmt = kmalloc(len + 1, GFP_KERNEL); | |
1138 | if (!print_fmt) | |
1139 | return -ENOMEM; | |
1140 | ||
1141 | /* Second: actually write the @print_fmt */ | |
1142 | __set_print_fmt(tp, print_fmt, len + 1); | |
1143 | tp->call.print_fmt = print_fmt; | |
1144 | ||
1145 | return 0; | |
1146 | } | |
1147 | ||
07b139c8 | 1148 | #ifdef CONFIG_PERF_EVENTS |
e08d1c65 MH |
1149 | |
1150 | /* Kprobe profile handler */ | |
2b106aab MH |
1151 | static __kprobes void |
1152 | kprobe_perf_func(struct trace_probe *tp, struct pt_regs *regs) | |
e08d1c65 | 1153 | { |
e08d1c65 | 1154 | struct ftrace_event_call *call = &tp->call; |
93ccae7a | 1155 | struct kprobe_trace_entry_head *entry; |
1c024eca | 1156 | struct hlist_head *head; |
e09c8614 | 1157 | int size, __size, dsize; |
4ed7c92d | 1158 | int rctx; |
e08d1c65 | 1159 | |
e09c8614 MH |
1160 | dsize = __get_data_size(tp, regs); |
1161 | __size = sizeof(*entry) + tp->size + dsize; | |
74ebb63e MH |
1162 | size = ALIGN(__size + sizeof(u32), sizeof(u64)); |
1163 | size -= sizeof(u32); | |
97d5a220 | 1164 | if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, |
a1a138d0 | 1165 | "profile buffer not large enough")) |
1e12a4a7 | 1166 | return; |
ce71b9df | 1167 | |
ff5f149b | 1168 | entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx); |
430ad5a6 | 1169 | if (!entry) |
1e12a4a7 | 1170 | return; |
a1a138d0 | 1171 | |
2b106aab | 1172 | entry->ip = (unsigned long)tp->rp.kp.addr; |
e09c8614 MH |
1173 | memset(&entry[1], 0, dsize); |
1174 | store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize); | |
444a2a3b | 1175 | |
3771f077 | 1176 | head = this_cpu_ptr(call->perf_events); |
e6dab5ff AV |
1177 | perf_trace_buf_submit(entry, size, rctx, |
1178 | entry->ip, 1, regs, head, NULL); | |
e08d1c65 MH |
1179 | } |
1180 | ||
1181 | /* Kretprobe profile handler */ | |
2b106aab MH |
1182 | static __kprobes void |
1183 | kretprobe_perf_func(struct trace_probe *tp, struct kretprobe_instance *ri, | |
1184 | struct pt_regs *regs) | |
e08d1c65 | 1185 | { |
e08d1c65 | 1186 | struct ftrace_event_call *call = &tp->call; |
93ccae7a | 1187 | struct kretprobe_trace_entry_head *entry; |
1c024eca | 1188 | struct hlist_head *head; |
e09c8614 | 1189 | int size, __size, dsize; |
4ed7c92d | 1190 | int rctx; |
e08d1c65 | 1191 | |
e09c8614 MH |
1192 | dsize = __get_data_size(tp, regs); |
1193 | __size = sizeof(*entry) + tp->size + dsize; | |
74ebb63e MH |
1194 | size = ALIGN(__size + sizeof(u32), sizeof(u64)); |
1195 | size -= sizeof(u32); | |
97d5a220 | 1196 | if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, |
a1a138d0 | 1197 | "profile buffer not large enough")) |
1e12a4a7 | 1198 | return; |
444a2a3b | 1199 | |
ff5f149b | 1200 | entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx); |
430ad5a6 | 1201 | if (!entry) |
1e12a4a7 | 1202 | return; |
e08d1c65 | 1203 | |
a1a138d0 MH |
1204 | entry->func = (unsigned long)tp->rp.kp.addr; |
1205 | entry->ret_ip = (unsigned long)ri->ret_addr; | |
e09c8614 | 1206 | store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize); |
444a2a3b | 1207 | |
3771f077 | 1208 | head = this_cpu_ptr(call->perf_events); |
e6dab5ff AV |
1209 | perf_trace_buf_submit(entry, size, rctx, |
1210 | entry->ret_ip, 1, regs, head, NULL); | |
e08d1c65 | 1211 | } |
07b139c8 | 1212 | #endif /* CONFIG_PERF_EVENTS */ |
50d78056 | 1213 | |
2239291a | 1214 | static __kprobes |
ceec0b6f JO |
1215 | int kprobe_register(struct ftrace_event_call *event, |
1216 | enum trace_reg type, void *data) | |
2239291a | 1217 | { |
1538f888 | 1218 | struct trace_probe *tp = (struct trace_probe *)event->data; |
41a7dd42 | 1219 | struct ftrace_event_file *file = data; |
1538f888 | 1220 | |
2239291a SR |
1221 | switch (type) { |
1222 | case TRACE_REG_REGISTER: | |
41a7dd42 | 1223 | return enable_trace_probe(tp, file); |
2239291a | 1224 | case TRACE_REG_UNREGISTER: |
41a7dd42 | 1225 | return disable_trace_probe(tp, file); |
2239291a SR |
1226 | |
1227 | #ifdef CONFIG_PERF_EVENTS | |
1228 | case TRACE_REG_PERF_REGISTER: | |
41a7dd42 | 1229 | return enable_trace_probe(tp, NULL); |
2239291a | 1230 | case TRACE_REG_PERF_UNREGISTER: |
41a7dd42 | 1231 | return disable_trace_probe(tp, NULL); |
ceec0b6f JO |
1232 | case TRACE_REG_PERF_OPEN: |
1233 | case TRACE_REG_PERF_CLOSE: | |
489c75c3 JO |
1234 | case TRACE_REG_PERF_ADD: |
1235 | case TRACE_REG_PERF_DEL: | |
ceec0b6f | 1236 | return 0; |
2239291a SR |
1237 | #endif |
1238 | } | |
1239 | return 0; | |
1240 | } | |
50d78056 MH |
1241 | |
1242 | static __kprobes | |
1243 | int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs) | |
1244 | { | |
1245 | struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp); | |
e08d1c65 | 1246 | |
48182bd2 MH |
1247 | tp->nhit++; |
1248 | ||
50d78056 | 1249 | if (tp->flags & TP_FLAG_TRACE) |
2b106aab | 1250 | kprobe_trace_func(tp, regs); |
07b139c8 | 1251 | #ifdef CONFIG_PERF_EVENTS |
50d78056 | 1252 | if (tp->flags & TP_FLAG_PROFILE) |
2b106aab | 1253 | kprobe_perf_func(tp, regs); |
07b139c8 | 1254 | #endif |
50d78056 MH |
1255 | return 0; /* We don't tweek kernel, so just return 0 */ |
1256 | } | |
1257 | ||
1258 | static __kprobes | |
1259 | int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs) | |
1260 | { | |
1261 | struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp); | |
1262 | ||
48182bd2 MH |
1263 | tp->nhit++; |
1264 | ||
50d78056 | 1265 | if (tp->flags & TP_FLAG_TRACE) |
2b106aab | 1266 | kretprobe_trace_func(tp, ri, regs); |
07b139c8 | 1267 | #ifdef CONFIG_PERF_EVENTS |
50d78056 | 1268 | if (tp->flags & TP_FLAG_PROFILE) |
2b106aab | 1269 | kretprobe_perf_func(tp, ri, regs); |
07b139c8 | 1270 | #endif |
50d78056 MH |
1271 | return 0; /* We don't tweek kernel, so just return 0 */ |
1272 | } | |
e08d1c65 | 1273 | |
a9a57763 SR |
1274 | static struct trace_event_functions kretprobe_funcs = { |
1275 | .trace = print_kretprobe_event | |
1276 | }; | |
1277 | ||
1278 | static struct trace_event_functions kprobe_funcs = { | |
1279 | .trace = print_kprobe_event | |
1280 | }; | |
1281 | ||
413d37d1 MH |
1282 | static int register_probe_event(struct trace_probe *tp) |
1283 | { | |
1284 | struct ftrace_event_call *call = &tp->call; | |
1285 | int ret; | |
1286 | ||
1287 | /* Initialize ftrace_event_call */ | |
ffb9f995 | 1288 | INIT_LIST_HEAD(&call->class->fields); |
7143f168 | 1289 | if (trace_probe_is_return(tp)) { |
80decc70 | 1290 | call->event.funcs = &kretprobe_funcs; |
2e33af02 | 1291 | call->class->define_fields = kretprobe_event_define_fields; |
413d37d1 | 1292 | } else { |
80decc70 | 1293 | call->event.funcs = &kprobe_funcs; |
2e33af02 | 1294 | call->class->define_fields = kprobe_event_define_fields; |
413d37d1 | 1295 | } |
a342a028 LJ |
1296 | if (set_print_fmt(tp) < 0) |
1297 | return -ENOMEM; | |
32c0edae SR |
1298 | ret = register_ftrace_event(&call->event); |
1299 | if (!ret) { | |
a342a028 | 1300 | kfree(call->print_fmt); |
ff50d991 | 1301 | return -ENODEV; |
a342a028 | 1302 | } |
553552ce | 1303 | call->flags = 0; |
2239291a | 1304 | call->class->reg = kprobe_register; |
413d37d1 MH |
1305 | call->data = tp; |
1306 | ret = trace_add_event_call(call); | |
ff50d991 | 1307 | if (ret) { |
413d37d1 | 1308 | pr_info("Failed to register kprobe event: %s\n", call->name); |
a342a028 | 1309 | kfree(call->print_fmt); |
80decc70 | 1310 | unregister_ftrace_event(&call->event); |
ff50d991 | 1311 | } |
413d37d1 MH |
1312 | return ret; |
1313 | } | |
1314 | ||
1315 | static void unregister_probe_event(struct trace_probe *tp) | |
1316 | { | |
ff50d991 | 1317 | /* tp->event is unregistered in trace_remove_event_call() */ |
413d37d1 | 1318 | trace_remove_event_call(&tp->call); |
a342a028 | 1319 | kfree(tp->call.print_fmt); |
413d37d1 MH |
1320 | } |
1321 | ||
25985edc | 1322 | /* Make a debugfs interface for controlling probe points */ |
413d37d1 MH |
1323 | static __init int init_kprobe_trace(void) |
1324 | { | |
1325 | struct dentry *d_tracer; | |
1326 | struct dentry *entry; | |
413d37d1 | 1327 | |
61424318 MH |
1328 | if (register_module_notifier(&trace_probe_module_nb)) |
1329 | return -EINVAL; | |
1330 | ||
413d37d1 MH |
1331 | d_tracer = tracing_init_dentry(); |
1332 | if (!d_tracer) | |
1333 | return 0; | |
1334 | ||
1335 | entry = debugfs_create_file("kprobe_events", 0644, d_tracer, | |
1336 | NULL, &kprobe_events_ops); | |
1337 | ||
cd7e7bd5 | 1338 | /* Event list interface */ |
413d37d1 MH |
1339 | if (!entry) |
1340 | pr_warning("Could not create debugfs " | |
1341 | "'kprobe_events' entry\n"); | |
cd7e7bd5 MH |
1342 | |
1343 | /* Profile interface */ | |
1344 | entry = debugfs_create_file("kprobe_profile", 0444, d_tracer, | |
1345 | NULL, &kprobe_profile_ops); | |
1346 | ||
1347 | if (!entry) | |
1348 | pr_warning("Could not create debugfs " | |
1349 | "'kprobe_profile' entry\n"); | |
413d37d1 MH |
1350 | return 0; |
1351 | } | |
1352 | fs_initcall(init_kprobe_trace); | |
1353 | ||
1354 | ||
1355 | #ifdef CONFIG_FTRACE_STARTUP_TEST | |
1356 | ||
265a5b7e SR |
1357 | /* |
1358 | * The "__used" keeps gcc from removing the function symbol | |
1359 | * from the kallsyms table. | |
1360 | */ | |
1361 | static __used int kprobe_trace_selftest_target(int a1, int a2, int a3, | |
1362 | int a4, int a5, int a6) | |
413d37d1 MH |
1363 | { |
1364 | return a1 + a2 + a3 + a4 + a5 + a6; | |
1365 | } | |
1366 | ||
41a7dd42 MH |
1367 | static struct ftrace_event_file * |
1368 | find_trace_probe_file(struct trace_probe *tp, struct trace_array *tr) | |
1369 | { | |
1370 | struct ftrace_event_file *file; | |
1371 | ||
1372 | list_for_each_entry(file, &tr->events, list) | |
1373 | if (file->event_call == &tp->call) | |
1374 | return file; | |
1375 | ||
1376 | return NULL; | |
1377 | } | |
1378 | ||
413d37d1 MH |
1379 | static __init int kprobe_trace_self_tests_init(void) |
1380 | { | |
231e36f4 | 1381 | int ret, warn = 0; |
413d37d1 | 1382 | int (*target)(int, int, int, int, int, int); |
231e36f4 | 1383 | struct trace_probe *tp; |
41a7dd42 | 1384 | struct ftrace_event_file *file; |
413d37d1 MH |
1385 | |
1386 | target = kprobe_trace_selftest_target; | |
1387 | ||
1388 | pr_info("Testing kprobe tracing: "); | |
1389 | ||
8ab83f56 SD |
1390 | ret = traceprobe_command("p:testprobe kprobe_trace_selftest_target " |
1391 | "$stack $stack0 +0($stack)", | |
1392 | create_trace_probe); | |
231e36f4 | 1393 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1394 | pr_warn("error on probing function entry.\n"); |
231e36f4 MH |
1395 | warn++; |
1396 | } else { | |
1397 | /* Enable trace point */ | |
7143f168 | 1398 | tp = find_trace_probe("testprobe", KPROBE_EVENT_SYSTEM); |
231e36f4 | 1399 | if (WARN_ON_ONCE(tp == NULL)) { |
41a7dd42 | 1400 | pr_warn("error on getting new probe.\n"); |
231e36f4 | 1401 | warn++; |
41a7dd42 MH |
1402 | } else { |
1403 | file = find_trace_probe_file(tp, top_trace_array()); | |
1404 | if (WARN_ON_ONCE(file == NULL)) { | |
1405 | pr_warn("error on getting probe file.\n"); | |
1406 | warn++; | |
1407 | } else | |
1408 | enable_trace_probe(tp, file); | |
1409 | } | |
231e36f4 | 1410 | } |
413d37d1 | 1411 | |
8ab83f56 SD |
1412 | ret = traceprobe_command("r:testprobe2 kprobe_trace_selftest_target " |
1413 | "$retval", create_trace_probe); | |
231e36f4 | 1414 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1415 | pr_warn("error on probing function return.\n"); |
231e36f4 MH |
1416 | warn++; |
1417 | } else { | |
1418 | /* Enable trace point */ | |
7143f168 | 1419 | tp = find_trace_probe("testprobe2", KPROBE_EVENT_SYSTEM); |
231e36f4 | 1420 | if (WARN_ON_ONCE(tp == NULL)) { |
41a7dd42 | 1421 | pr_warn("error on getting 2nd new probe.\n"); |
231e36f4 | 1422 | warn++; |
41a7dd42 MH |
1423 | } else { |
1424 | file = find_trace_probe_file(tp, top_trace_array()); | |
1425 | if (WARN_ON_ONCE(file == NULL)) { | |
1426 | pr_warn("error on getting probe file.\n"); | |
1427 | warn++; | |
1428 | } else | |
1429 | enable_trace_probe(tp, file); | |
1430 | } | |
231e36f4 MH |
1431 | } |
1432 | ||
1433 | if (warn) | |
1434 | goto end; | |
413d37d1 MH |
1435 | |
1436 | ret = target(1, 2, 3, 4, 5, 6); | |
1437 | ||
02ca1521 MH |
1438 | /* Disable trace points before removing it */ |
1439 | tp = find_trace_probe("testprobe", KPROBE_EVENT_SYSTEM); | |
1440 | if (WARN_ON_ONCE(tp == NULL)) { | |
41a7dd42 | 1441 | pr_warn("error on getting test probe.\n"); |
02ca1521 | 1442 | warn++; |
41a7dd42 MH |
1443 | } else { |
1444 | file = find_trace_probe_file(tp, top_trace_array()); | |
1445 | if (WARN_ON_ONCE(file == NULL)) { | |
1446 | pr_warn("error on getting probe file.\n"); | |
1447 | warn++; | |
1448 | } else | |
1449 | disable_trace_probe(tp, file); | |
1450 | } | |
02ca1521 MH |
1451 | |
1452 | tp = find_trace_probe("testprobe2", KPROBE_EVENT_SYSTEM); | |
1453 | if (WARN_ON_ONCE(tp == NULL)) { | |
41a7dd42 | 1454 | pr_warn("error on getting 2nd test probe.\n"); |
02ca1521 | 1455 | warn++; |
41a7dd42 MH |
1456 | } else { |
1457 | file = find_trace_probe_file(tp, top_trace_array()); | |
1458 | if (WARN_ON_ONCE(file == NULL)) { | |
1459 | pr_warn("error on getting probe file.\n"); | |
1460 | warn++; | |
1461 | } else | |
1462 | disable_trace_probe(tp, file); | |
1463 | } | |
02ca1521 | 1464 | |
8ab83f56 | 1465 | ret = traceprobe_command("-:testprobe", create_trace_probe); |
231e36f4 | 1466 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1467 | pr_warn("error on deleting a probe.\n"); |
231e36f4 MH |
1468 | warn++; |
1469 | } | |
1470 | ||
8ab83f56 | 1471 | ret = traceprobe_command("-:testprobe2", create_trace_probe); |
231e36f4 | 1472 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1473 | pr_warn("error on deleting a probe.\n"); |
231e36f4 MH |
1474 | warn++; |
1475 | } | |
413d37d1 | 1476 | |
231e36f4 | 1477 | end: |
7143f168 | 1478 | release_all_trace_probes(); |
231e36f4 MH |
1479 | if (warn) |
1480 | pr_cont("NG: Some tests are failed. Please check them.\n"); | |
1481 | else | |
1482 | pr_cont("OK\n"); | |
413d37d1 MH |
1483 | return 0; |
1484 | } | |
1485 | ||
1486 | late_initcall(kprobe_trace_self_tests_init); | |
1487 | ||
1488 | #endif |