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; |
b04d52e3 | 38 | struct list_head 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 | ||
b04d52e3 ON |
44 | struct event_file_link { |
45 | struct ftrace_event_file *file; | |
46 | struct list_head list; | |
47 | }; | |
48 | ||
a82378d8 MH |
49 | #define SIZEOF_TRACE_PROBE(n) \ |
50 | (offsetof(struct trace_probe, args) + \ | |
eca0d916 | 51 | (sizeof(struct probe_arg) * (n))) |
a82378d8 | 52 | |
93ccae7a | 53 | |
db02038f | 54 | static __kprobes bool trace_probe_is_return(struct trace_probe *tp) |
413d37d1 | 55 | { |
4a846b44 | 56 | return tp->rp.handler != NULL; |
413d37d1 MH |
57 | } |
58 | ||
7143f168 | 59 | static __kprobes const char *trace_probe_symbol(struct trace_probe *tp) |
413d37d1 MH |
60 | { |
61 | return tp->symbol ? tp->symbol : "unknown"; | |
62 | } | |
63 | ||
61424318 MH |
64 | static __kprobes unsigned long trace_probe_offset(struct trace_probe *tp) |
65 | { | |
66 | return tp->rp.kp.offset; | |
67 | } | |
68 | ||
69 | static __kprobes bool trace_probe_is_enabled(struct trace_probe *tp) | |
70 | { | |
71 | return !!(tp->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE)); | |
72 | } | |
73 | ||
74 | static __kprobes bool trace_probe_is_registered(struct trace_probe *tp) | |
75 | { | |
76 | return !!(tp->flags & TP_FLAG_REGISTERED); | |
77 | } | |
78 | ||
79 | static __kprobes bool trace_probe_has_gone(struct trace_probe *tp) | |
80 | { | |
81 | return !!(kprobe_gone(&tp->rp.kp)); | |
82 | } | |
83 | ||
84 | static __kprobes bool trace_probe_within_module(struct trace_probe *tp, | |
85 | struct module *mod) | |
86 | { | |
87 | int len = strlen(mod->name); | |
88 | const char *name = trace_probe_symbol(tp); | |
89 | return strncmp(mod->name, name, len) == 0 && name[len] == ':'; | |
90 | } | |
91 | ||
92 | static __kprobes bool trace_probe_is_on_module(struct trace_probe *tp) | |
93 | { | |
94 | return !!strchr(trace_probe_symbol(tp), ':'); | |
95 | } | |
96 | ||
413d37d1 | 97 | static int register_probe_event(struct trace_probe *tp); |
40c32592 | 98 | static int unregister_probe_event(struct trace_probe *tp); |
413d37d1 MH |
99 | |
100 | static DEFINE_MUTEX(probe_lock); | |
101 | static LIST_HEAD(probe_list); | |
102 | ||
50d78056 MH |
103 | static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs); |
104 | static int kretprobe_dispatcher(struct kretprobe_instance *ri, | |
105 | struct pt_regs *regs); | |
106 | ||
4a846b44 MH |
107 | /* |
108 | * Allocate new trace_probe and initialize it (including kprobes). | |
109 | */ | |
f52487e9 MH |
110 | static struct trace_probe *alloc_trace_probe(const char *group, |
111 | const char *event, | |
4a846b44 MH |
112 | void *addr, |
113 | const char *symbol, | |
114 | unsigned long offs, | |
3a6b7666 | 115 | int nargs, bool is_return) |
413d37d1 MH |
116 | { |
117 | struct trace_probe *tp; | |
6f3cf440 | 118 | int ret = -ENOMEM; |
413d37d1 | 119 | |
a82378d8 | 120 | tp = kzalloc(SIZEOF_TRACE_PROBE(nargs), GFP_KERNEL); |
413d37d1 | 121 | if (!tp) |
6f3cf440 | 122 | return ERR_PTR(ret); |
413d37d1 MH |
123 | |
124 | if (symbol) { | |
125 | tp->symbol = kstrdup(symbol, GFP_KERNEL); | |
126 | if (!tp->symbol) | |
127 | goto error; | |
4a846b44 MH |
128 | tp->rp.kp.symbol_name = tp->symbol; |
129 | tp->rp.kp.offset = offs; | |
130 | } else | |
131 | tp->rp.kp.addr = addr; | |
132 | ||
133 | if (is_return) | |
50d78056 | 134 | tp->rp.handler = kretprobe_dispatcher; |
4a846b44 | 135 | else |
50d78056 | 136 | tp->rp.kp.pre_handler = kprobe_dispatcher; |
4a846b44 | 137 | |
da34634f | 138 | if (!event || !is_good_name(event)) { |
6f3cf440 | 139 | ret = -EINVAL; |
4263565d | 140 | goto error; |
6f3cf440 MH |
141 | } |
142 | ||
2239291a | 143 | tp->call.class = &tp->class; |
4263565d MH |
144 | tp->call.name = kstrdup(event, GFP_KERNEL); |
145 | if (!tp->call.name) | |
146 | goto error; | |
413d37d1 | 147 | |
da34634f | 148 | if (!group || !is_good_name(group)) { |
6f3cf440 | 149 | ret = -EINVAL; |
f52487e9 | 150 | goto error; |
6f3cf440 MH |
151 | } |
152 | ||
2239291a SR |
153 | tp->class.system = kstrdup(group, GFP_KERNEL); |
154 | if (!tp->class.system) | |
f52487e9 MH |
155 | goto error; |
156 | ||
413d37d1 | 157 | INIT_LIST_HEAD(&tp->list); |
b04d52e3 | 158 | INIT_LIST_HEAD(&tp->files); |
413d37d1 MH |
159 | return tp; |
160 | error: | |
f52487e9 | 161 | kfree(tp->call.name); |
413d37d1 MH |
162 | kfree(tp->symbol); |
163 | kfree(tp); | |
6f3cf440 | 164 | return ERR_PTR(ret); |
413d37d1 MH |
165 | } |
166 | ||
167 | static void free_trace_probe(struct trace_probe *tp) | |
168 | { | |
169 | int i; | |
170 | ||
171 | for (i = 0; i < tp->nr_args; i++) | |
8ab83f56 | 172 | traceprobe_free_probe_arg(&tp->args[i]); |
413d37d1 | 173 | |
8f082018 | 174 | kfree(tp->call.class->system); |
413d37d1 MH |
175 | kfree(tp->call.name); |
176 | kfree(tp->symbol); | |
177 | kfree(tp); | |
178 | } | |
179 | ||
7143f168 | 180 | static struct trace_probe *find_trace_probe(const char *event, |
dd004c47 | 181 | const char *group) |
413d37d1 MH |
182 | { |
183 | struct trace_probe *tp; | |
184 | ||
185 | list_for_each_entry(tp, &probe_list, list) | |
dd004c47 | 186 | if (strcmp(tp->call.name, event) == 0 && |
8f082018 | 187 | strcmp(tp->call.class->system, group) == 0) |
413d37d1 MH |
188 | return tp; |
189 | return NULL; | |
190 | } | |
191 | ||
41a7dd42 MH |
192 | /* |
193 | * Enable trace_probe | |
194 | * if the file is NULL, enable "perf" handler, or enable "trace" handler. | |
195 | */ | |
196 | static int | |
197 | enable_trace_probe(struct trace_probe *tp, struct ftrace_event_file *file) | |
1538f888 MH |
198 | { |
199 | int ret = 0; | |
200 | ||
41a7dd42 | 201 | if (file) { |
b04d52e3 ON |
202 | struct event_file_link *link; |
203 | ||
204 | link = kmalloc(sizeof(*link), GFP_KERNEL); | |
205 | if (!link) { | |
41a7dd42 | 206 | ret = -ENOMEM; |
3fe3d619 | 207 | goto out; |
41a7dd42 | 208 | } |
41a7dd42 | 209 | |
b04d52e3 ON |
210 | link->file = file; |
211 | list_add_tail_rcu(&link->list, &tp->files); | |
41a7dd42 | 212 | |
b04d52e3 | 213 | tp->flags |= TP_FLAG_TRACE; |
41a7dd42 MH |
214 | } else |
215 | tp->flags |= TP_FLAG_PROFILE; | |
216 | ||
195a84d9 | 217 | if (trace_probe_is_registered(tp) && !trace_probe_has_gone(tp)) { |
1538f888 MH |
218 | if (trace_probe_is_return(tp)) |
219 | ret = enable_kretprobe(&tp->rp); | |
220 | else | |
221 | ret = enable_kprobe(&tp->rp.kp); | |
222 | } | |
3fe3d619 | 223 | out: |
1538f888 MH |
224 | return ret; |
225 | } | |
226 | ||
b04d52e3 ON |
227 | static struct event_file_link * |
228 | find_event_file_link(struct trace_probe *tp, struct ftrace_event_file *file) | |
41a7dd42 | 229 | { |
b04d52e3 | 230 | struct event_file_link *link; |
41a7dd42 | 231 | |
b04d52e3 ON |
232 | list_for_each_entry(link, &tp->files, list) |
233 | if (link->file == file) | |
234 | return link; | |
41a7dd42 | 235 | |
b04d52e3 | 236 | return NULL; |
41a7dd42 MH |
237 | } |
238 | ||
239 | /* | |
240 | * Disable trace_probe | |
241 | * if the file is NULL, disable "perf" handler, or disable "trace" handler. | |
242 | */ | |
243 | static int | |
244 | disable_trace_probe(struct trace_probe *tp, struct ftrace_event_file *file) | |
1538f888 | 245 | { |
a232e270 MH |
246 | struct event_file_link *link = NULL; |
247 | int wait = 0; | |
41a7dd42 MH |
248 | int ret = 0; |
249 | ||
41a7dd42 | 250 | if (file) { |
b04d52e3 ON |
251 | link = find_event_file_link(tp, file); |
252 | if (!link) { | |
41a7dd42 | 253 | ret = -EINVAL; |
3fe3d619 | 254 | goto out; |
41a7dd42 MH |
255 | } |
256 | ||
b04d52e3 | 257 | list_del_rcu(&link->list); |
a232e270 | 258 | wait = 1; |
b04d52e3 ON |
259 | if (!list_empty(&tp->files)) |
260 | goto out; | |
41a7dd42 | 261 | |
b04d52e3 | 262 | tp->flags &= ~TP_FLAG_TRACE; |
41a7dd42 MH |
263 | } else |
264 | tp->flags &= ~TP_FLAG_PROFILE; | |
265 | ||
61424318 | 266 | if (!trace_probe_is_enabled(tp) && trace_probe_is_registered(tp)) { |
1538f888 MH |
267 | if (trace_probe_is_return(tp)) |
268 | disable_kretprobe(&tp->rp); | |
269 | else | |
270 | disable_kprobe(&tp->rp.kp); | |
a232e270 | 271 | wait = 1; |
1538f888 | 272 | } |
3fe3d619 | 273 | out: |
a232e270 MH |
274 | if (wait) { |
275 | /* | |
276 | * Synchronize with kprobe_trace_func/kretprobe_trace_func | |
277 | * to ensure disabled (all running handlers are finished). | |
278 | * This is not only for kfree(), but also the caller, | |
279 | * trace_remove_event_call() supposes it for releasing | |
280 | * event_call related objects, which will be accessed in | |
281 | * the kprobe_trace_func/kretprobe_trace_func. | |
282 | */ | |
283 | synchronize_sched(); | |
284 | kfree(link); /* Ignored if link == NULL */ | |
285 | } | |
286 | ||
41a7dd42 | 287 | return ret; |
1538f888 MH |
288 | } |
289 | ||
61424318 MH |
290 | /* Internal register function - just handle k*probes and flags */ |
291 | static int __register_trace_probe(struct trace_probe *tp) | |
413d37d1 | 292 | { |
7f6878a3 | 293 | int i, ret; |
61424318 MH |
294 | |
295 | if (trace_probe_is_registered(tp)) | |
296 | return -EINVAL; | |
297 | ||
7f6878a3 | 298 | for (i = 0; i < tp->nr_args; i++) |
8ab83f56 | 299 | traceprobe_update_arg(&tp->args[i]); |
7f6878a3 | 300 | |
61424318 MH |
301 | /* Set/clear disabled flag according to tp->flag */ |
302 | if (trace_probe_is_enabled(tp)) | |
303 | tp->rp.kp.flags &= ~KPROBE_FLAG_DISABLED; | |
304 | else | |
305 | tp->rp.kp.flags |= KPROBE_FLAG_DISABLED; | |
306 | ||
7143f168 | 307 | if (trace_probe_is_return(tp)) |
61424318 | 308 | ret = register_kretprobe(&tp->rp); |
413d37d1 | 309 | else |
61424318 MH |
310 | ret = register_kprobe(&tp->rp.kp); |
311 | ||
312 | if (ret == 0) | |
313 | tp->flags |= TP_FLAG_REGISTERED; | |
314 | else { | |
315 | pr_warning("Could not insert probe at %s+%lu: %d\n", | |
316 | trace_probe_symbol(tp), trace_probe_offset(tp), ret); | |
317 | if (ret == -ENOENT && trace_probe_is_on_module(tp)) { | |
318 | pr_warning("This probe might be able to register after" | |
319 | "target module is loaded. Continue.\n"); | |
320 | ret = 0; | |
321 | } else if (ret == -EILSEQ) { | |
322 | pr_warning("Probing address(0x%p) is not an " | |
323 | "instruction boundary.\n", | |
324 | tp->rp.kp.addr); | |
325 | ret = -EINVAL; | |
326 | } | |
327 | } | |
328 | ||
329 | return ret; | |
330 | } | |
331 | ||
332 | /* Internal unregister function - just handle k*probes and flags */ | |
333 | static void __unregister_trace_probe(struct trace_probe *tp) | |
334 | { | |
335 | if (trace_probe_is_registered(tp)) { | |
336 | if (trace_probe_is_return(tp)) | |
337 | unregister_kretprobe(&tp->rp); | |
338 | else | |
339 | unregister_kprobe(&tp->rp.kp); | |
340 | tp->flags &= ~TP_FLAG_REGISTERED; | |
341 | /* Cleanup kprobe for reuse */ | |
342 | if (tp->rp.kp.symbol_name) | |
343 | tp->rp.kp.addr = NULL; | |
344 | } | |
345 | } | |
346 | ||
347 | /* Unregister a trace_probe and probe_event: call with locking probe_lock */ | |
02ca1521 | 348 | static int unregister_trace_probe(struct trace_probe *tp) |
61424318 | 349 | { |
02ca1521 MH |
350 | /* Enabled event can not be unregistered */ |
351 | if (trace_probe_is_enabled(tp)) | |
352 | return -EBUSY; | |
353 | ||
40c32592 SRRH |
354 | /* Will fail if probe is being used by ftrace or perf */ |
355 | if (unregister_probe_event(tp)) | |
356 | return -EBUSY; | |
357 | ||
61424318 | 358 | __unregister_trace_probe(tp); |
413d37d1 | 359 | list_del(&tp->list); |
02ca1521 MH |
360 | |
361 | return 0; | |
413d37d1 MH |
362 | } |
363 | ||
364 | /* Register a trace_probe and probe_event */ | |
365 | static int register_trace_probe(struct trace_probe *tp) | |
366 | { | |
367 | struct trace_probe *old_tp; | |
368 | int ret; | |
369 | ||
370 | mutex_lock(&probe_lock); | |
371 | ||
61424318 | 372 | /* Delete old (same name) event if exist */ |
7143f168 | 373 | old_tp = find_trace_probe(tp->call.name, tp->call.class->system); |
2d5e067e | 374 | if (old_tp) { |
02ca1521 MH |
375 | ret = unregister_trace_probe(old_tp); |
376 | if (ret < 0) | |
377 | goto end; | |
2d5e067e MH |
378 | free_trace_probe(old_tp); |
379 | } | |
61424318 MH |
380 | |
381 | /* Register new event */ | |
2d5e067e MH |
382 | ret = register_probe_event(tp); |
383 | if (ret) { | |
426d3107 | 384 | pr_warning("Failed to register probe event(%d)\n", ret); |
2d5e067e MH |
385 | goto end; |
386 | } | |
387 | ||
61424318 MH |
388 | /* Register k*probe */ |
389 | ret = __register_trace_probe(tp); | |
390 | if (ret < 0) | |
2d5e067e | 391 | unregister_probe_event(tp); |
61424318 | 392 | else |
2d5e067e | 393 | list_add_tail(&tp->list, &probe_list); |
61424318 | 394 | |
413d37d1 MH |
395 | end: |
396 | mutex_unlock(&probe_lock); | |
397 | return ret; | |
398 | } | |
399 | ||
61424318 MH |
400 | /* Module notifier call back, checking event on the module */ |
401 | static int trace_probe_module_callback(struct notifier_block *nb, | |
402 | unsigned long val, void *data) | |
403 | { | |
404 | struct module *mod = data; | |
405 | struct trace_probe *tp; | |
406 | int ret; | |
407 | ||
408 | if (val != MODULE_STATE_COMING) | |
409 | return NOTIFY_DONE; | |
410 | ||
411 | /* Update probes on coming module */ | |
412 | mutex_lock(&probe_lock); | |
413 | list_for_each_entry(tp, &probe_list, list) { | |
414 | if (trace_probe_within_module(tp, mod)) { | |
02ca1521 | 415 | /* Don't need to check busy - this should have gone. */ |
61424318 MH |
416 | __unregister_trace_probe(tp); |
417 | ret = __register_trace_probe(tp); | |
418 | if (ret) | |
419 | pr_warning("Failed to re-register probe %s on" | |
420 | "%s: %d\n", | |
421 | tp->call.name, mod->name, ret); | |
422 | } | |
423 | } | |
424 | mutex_unlock(&probe_lock); | |
425 | ||
426 | return NOTIFY_DONE; | |
427 | } | |
428 | ||
429 | static struct notifier_block trace_probe_module_nb = { | |
430 | .notifier_call = trace_probe_module_callback, | |
431 | .priority = 1 /* Invoked after kprobe module callback */ | |
432 | }; | |
433 | ||
413d37d1 MH |
434 | static int create_trace_probe(int argc, char **argv) |
435 | { | |
436 | /* | |
437 | * Argument syntax: | |
61424318 MH |
438 | * - Add kprobe: p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS] |
439 | * - Add kretprobe: r[:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS] | |
413d37d1 | 440 | * Fetch args: |
2e06ff63 MH |
441 | * $retval : fetch return value |
442 | * $stack : fetch stack address | |
443 | * $stackN : fetch Nth of stack (N:0-) | |
413d37d1 MH |
444 | * @ADDR : fetch memory at ADDR (ADDR should be in kernel) |
445 | * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol) | |
446 | * %REG : fetch register REG | |
93ccae7a | 447 | * Dereferencing memory fetch: |
413d37d1 | 448 | * +|-offs(ARG) : fetch memory at ARG +|- offs address. |
eca0d916 MH |
449 | * Alias name of args: |
450 | * NAME=FETCHARG : set NAME as alias of FETCHARG. | |
93ccae7a MH |
451 | * Type of args: |
452 | * FETCHARG:TYPE : use TYPE instead of unsigned long. | |
413d37d1 MH |
453 | */ |
454 | struct trace_probe *tp; | |
413d37d1 | 455 | int i, ret = 0; |
3a6b7666 | 456 | bool is_return = false, is_delete = false; |
93ccae7a | 457 | char *symbol = NULL, *event = NULL, *group = NULL; |
da34634f | 458 | char *arg; |
2fba0c88 | 459 | unsigned long offset = 0; |
413d37d1 | 460 | void *addr = NULL; |
4a846b44 | 461 | char buf[MAX_EVENT_NAME_LEN]; |
413d37d1 | 462 | |
a7c312be | 463 | /* argc must be >= 1 */ |
413d37d1 | 464 | if (argv[0][0] == 'p') |
3a6b7666 | 465 | is_return = false; |
413d37d1 | 466 | else if (argv[0][0] == 'r') |
3a6b7666 | 467 | is_return = true; |
a7c312be | 468 | else if (argv[0][0] == '-') |
3a6b7666 | 469 | is_delete = true; |
e63cc239 | 470 | else { |
a7c312be MH |
471 | pr_info("Probe definition must be started with 'p', 'r' or" |
472 | " '-'.\n"); | |
413d37d1 | 473 | return -EINVAL; |
e63cc239 | 474 | } |
413d37d1 MH |
475 | |
476 | if (argv[0][1] == ':') { | |
477 | event = &argv[0][2]; | |
f52487e9 MH |
478 | if (strchr(event, '/')) { |
479 | group = event; | |
480 | event = strchr(group, '/') + 1; | |
481 | event[-1] = '\0'; | |
482 | if (strlen(group) == 0) { | |
a5efd925 | 483 | pr_info("Group name is not specified\n"); |
f52487e9 MH |
484 | return -EINVAL; |
485 | } | |
486 | } | |
413d37d1 | 487 | if (strlen(event) == 0) { |
a5efd925 | 488 | pr_info("Event name is not specified\n"); |
413d37d1 MH |
489 | return -EINVAL; |
490 | } | |
491 | } | |
a7c312be MH |
492 | if (!group) |
493 | group = KPROBE_EVENT_SYSTEM; | |
413d37d1 | 494 | |
a7c312be MH |
495 | if (is_delete) { |
496 | if (!event) { | |
497 | pr_info("Delete command needs an event name.\n"); | |
498 | return -EINVAL; | |
499 | } | |
9da79ab8 | 500 | mutex_lock(&probe_lock); |
7143f168 | 501 | tp = find_trace_probe(event, group); |
a7c312be | 502 | if (!tp) { |
9da79ab8 | 503 | mutex_unlock(&probe_lock); |
a7c312be MH |
504 | pr_info("Event %s/%s doesn't exist.\n", group, event); |
505 | return -ENOENT; | |
506 | } | |
507 | /* delete an event */ | |
02ca1521 MH |
508 | ret = unregister_trace_probe(tp); |
509 | if (ret == 0) | |
510 | free_trace_probe(tp); | |
9da79ab8 | 511 | mutex_unlock(&probe_lock); |
02ca1521 | 512 | return ret; |
a7c312be MH |
513 | } |
514 | ||
515 | if (argc < 2) { | |
516 | pr_info("Probe point is not specified.\n"); | |
517 | return -EINVAL; | |
518 | } | |
413d37d1 | 519 | if (isdigit(argv[1][0])) { |
e63cc239 MH |
520 | if (is_return) { |
521 | pr_info("Return probe point must be a symbol.\n"); | |
413d37d1 | 522 | return -EINVAL; |
e63cc239 | 523 | } |
413d37d1 | 524 | /* an address specified */ |
bcd83ea6 | 525 | ret = kstrtoul(&argv[1][0], 0, (unsigned long *)&addr); |
e63cc239 MH |
526 | if (ret) { |
527 | pr_info("Failed to parse address.\n"); | |
413d37d1 | 528 | return ret; |
e63cc239 | 529 | } |
413d37d1 MH |
530 | } else { |
531 | /* a symbol specified */ | |
532 | symbol = argv[1]; | |
533 | /* TODO: support .init module functions */ | |
8ab83f56 | 534 | ret = traceprobe_split_symbol_offset(symbol, &offset); |
e63cc239 MH |
535 | if (ret) { |
536 | pr_info("Failed to parse symbol.\n"); | |
413d37d1 | 537 | return ret; |
e63cc239 MH |
538 | } |
539 | if (offset && is_return) { | |
540 | pr_info("Return probe must be used without offset.\n"); | |
413d37d1 | 541 | return -EINVAL; |
e63cc239 | 542 | } |
413d37d1 | 543 | } |
a82378d8 | 544 | argc -= 2; argv += 2; |
413d37d1 MH |
545 | |
546 | /* setup a probe */ | |
4263565d MH |
547 | if (!event) { |
548 | /* Make a new event name */ | |
4263565d | 549 | if (symbol) |
6f3cf440 | 550 | snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld", |
4263565d MH |
551 | is_return ? 'r' : 'p', symbol, offset); |
552 | else | |
6f3cf440 | 553 | snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p", |
4263565d | 554 | is_return ? 'r' : 'p', addr); |
4a846b44 MH |
555 | event = buf; |
556 | } | |
f52487e9 MH |
557 | tp = alloc_trace_probe(group, event, addr, symbol, offset, argc, |
558 | is_return); | |
e63cc239 MH |
559 | if (IS_ERR(tp)) { |
560 | pr_info("Failed to allocate trace_probe.(%d)\n", | |
561 | (int)PTR_ERR(tp)); | |
413d37d1 | 562 | return PTR_ERR(tp); |
e63cc239 | 563 | } |
413d37d1 | 564 | |
413d37d1 | 565 | /* parse arguments */ |
a82378d8 MH |
566 | ret = 0; |
567 | for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { | |
61a52736 MH |
568 | /* Increment count for freeing args in error case */ |
569 | tp->nr_args++; | |
570 | ||
eca0d916 MH |
571 | /* Parse argument name */ |
572 | arg = strchr(argv[i], '='); | |
aba91595 | 573 | if (arg) { |
eca0d916 | 574 | *arg++ = '\0'; |
aba91595 MH |
575 | tp->args[i].name = kstrdup(argv[i], GFP_KERNEL); |
576 | } else { | |
eca0d916 | 577 | arg = argv[i]; |
aba91595 MH |
578 | /* If argument name is omitted, set "argN" */ |
579 | snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1); | |
580 | tp->args[i].name = kstrdup(buf, GFP_KERNEL); | |
581 | } | |
a703d946 | 582 | |
ba8665d7 | 583 | if (!tp->args[i].name) { |
aba91595 | 584 | pr_info("Failed to allocate argument[%d] name.\n", i); |
ba8665d7 | 585 | ret = -ENOMEM; |
413d37d1 MH |
586 | goto error; |
587 | } | |
da34634f MH |
588 | |
589 | if (!is_good_name(tp->args[i].name)) { | |
590 | pr_info("Invalid argument[%d] name: %s\n", | |
591 | i, tp->args[i].name); | |
592 | ret = -EINVAL; | |
593 | goto error; | |
594 | } | |
93ccae7a | 595 | |
8ab83f56 SD |
596 | if (traceprobe_conflict_field_name(tp->args[i].name, |
597 | tp->args, i)) { | |
aba91595 | 598 | pr_info("Argument[%d] name '%s' conflicts with " |
93ccae7a MH |
599 | "another field.\n", i, argv[i]); |
600 | ret = -EINVAL; | |
601 | goto error; | |
602 | } | |
ba8665d7 MH |
603 | |
604 | /* Parse fetch argument */ | |
8ab83f56 | 605 | ret = traceprobe_parse_probe_arg(arg, &tp->size, &tp->args[i], |
f3f096cf | 606 | is_return, true); |
e63cc239 | 607 | if (ret) { |
aba91595 | 608 | pr_info("Parse error at argument[%d]. (%d)\n", i, ret); |
413d37d1 | 609 | goto error; |
e63cc239 | 610 | } |
413d37d1 | 611 | } |
413d37d1 MH |
612 | |
613 | ret = register_trace_probe(tp); | |
614 | if (ret) | |
615 | goto error; | |
616 | return 0; | |
617 | ||
618 | error: | |
619 | free_trace_probe(tp); | |
620 | return ret; | |
621 | } | |
622 | ||
02ca1521 | 623 | static int release_all_trace_probes(void) |
413d37d1 MH |
624 | { |
625 | struct trace_probe *tp; | |
02ca1521 | 626 | int ret = 0; |
413d37d1 MH |
627 | |
628 | mutex_lock(&probe_lock); | |
02ca1521 MH |
629 | /* Ensure no probe is in use. */ |
630 | list_for_each_entry(tp, &probe_list, list) | |
631 | if (trace_probe_is_enabled(tp)) { | |
632 | ret = -EBUSY; | |
633 | goto end; | |
634 | } | |
413d37d1 MH |
635 | /* TODO: Use batch unregistration */ |
636 | while (!list_empty(&probe_list)) { | |
637 | tp = list_entry(probe_list.next, struct trace_probe, list); | |
40c32592 SRRH |
638 | ret = unregister_trace_probe(tp); |
639 | if (ret) | |
640 | goto end; | |
413d37d1 MH |
641 | free_trace_probe(tp); |
642 | } | |
02ca1521 MH |
643 | |
644 | end: | |
413d37d1 | 645 | mutex_unlock(&probe_lock); |
02ca1521 MH |
646 | |
647 | return ret; | |
413d37d1 MH |
648 | } |
649 | ||
413d37d1 MH |
650 | /* Probes listing interfaces */ |
651 | static void *probes_seq_start(struct seq_file *m, loff_t *pos) | |
652 | { | |
653 | mutex_lock(&probe_lock); | |
654 | return seq_list_start(&probe_list, *pos); | |
655 | } | |
656 | ||
657 | static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos) | |
658 | { | |
659 | return seq_list_next(v, &probe_list, pos); | |
660 | } | |
661 | ||
662 | static void probes_seq_stop(struct seq_file *m, void *v) | |
663 | { | |
664 | mutex_unlock(&probe_lock); | |
665 | } | |
666 | ||
667 | static int probes_seq_show(struct seq_file *m, void *v) | |
668 | { | |
669 | struct trace_probe *tp = v; | |
93ccae7a | 670 | int i; |
413d37d1 | 671 | |
7143f168 | 672 | seq_printf(m, "%c", trace_probe_is_return(tp) ? 'r' : 'p'); |
8f082018 | 673 | seq_printf(m, ":%s/%s", tp->call.class->system, tp->call.name); |
413d37d1 | 674 | |
52a11f35 LJ |
675 | if (!tp->symbol) |
676 | seq_printf(m, " 0x%p", tp->rp.kp.addr); | |
677 | else if (tp->rp.kp.offset) | |
7143f168 MH |
678 | seq_printf(m, " %s+%u", trace_probe_symbol(tp), |
679 | tp->rp.kp.offset); | |
413d37d1 | 680 | else |
7143f168 | 681 | seq_printf(m, " %s", trace_probe_symbol(tp)); |
413d37d1 | 682 | |
93ccae7a MH |
683 | for (i = 0; i < tp->nr_args; i++) |
684 | seq_printf(m, " %s=%s", tp->args[i].name, tp->args[i].comm); | |
413d37d1 | 685 | seq_printf(m, "\n"); |
93ccae7a | 686 | |
413d37d1 MH |
687 | return 0; |
688 | } | |
689 | ||
690 | static const struct seq_operations probes_seq_op = { | |
691 | .start = probes_seq_start, | |
692 | .next = probes_seq_next, | |
693 | .stop = probes_seq_stop, | |
694 | .show = probes_seq_show | |
695 | }; | |
696 | ||
697 | static int probes_open(struct inode *inode, struct file *file) | |
698 | { | |
02ca1521 MH |
699 | int ret; |
700 | ||
701 | if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { | |
702 | ret = release_all_trace_probes(); | |
703 | if (ret < 0) | |
704 | return ret; | |
705 | } | |
413d37d1 MH |
706 | |
707 | return seq_open(file, &probes_seq_op); | |
708 | } | |
709 | ||
413d37d1 MH |
710 | static ssize_t probes_write(struct file *file, const char __user *buffer, |
711 | size_t count, loff_t *ppos) | |
712 | { | |
8ab83f56 SD |
713 | return traceprobe_probes_write(file, buffer, count, ppos, |
714 | create_trace_probe); | |
413d37d1 MH |
715 | } |
716 | ||
717 | static const struct file_operations kprobe_events_ops = { | |
718 | .owner = THIS_MODULE, | |
719 | .open = probes_open, | |
720 | .read = seq_read, | |
721 | .llseek = seq_lseek, | |
722 | .release = seq_release, | |
723 | .write = probes_write, | |
724 | }; | |
725 | ||
cd7e7bd5 MH |
726 | /* Probes profiling interfaces */ |
727 | static int probes_profile_seq_show(struct seq_file *m, void *v) | |
728 | { | |
729 | struct trace_probe *tp = v; | |
730 | ||
731 | seq_printf(m, " %-44s %15lu %15lu\n", tp->call.name, tp->nhit, | |
4a846b44 | 732 | tp->rp.kp.nmissed); |
cd7e7bd5 MH |
733 | |
734 | return 0; | |
735 | } | |
736 | ||
737 | static const struct seq_operations profile_seq_op = { | |
738 | .start = probes_seq_start, | |
739 | .next = probes_seq_next, | |
740 | .stop = probes_seq_stop, | |
741 | .show = probes_profile_seq_show | |
742 | }; | |
743 | ||
744 | static int profile_open(struct inode *inode, struct file *file) | |
745 | { | |
746 | return seq_open(file, &profile_seq_op); | |
747 | } | |
748 | ||
749 | static const struct file_operations kprobe_profile_ops = { | |
750 | .owner = THIS_MODULE, | |
751 | .open = profile_open, | |
752 | .read = seq_read, | |
753 | .llseek = seq_lseek, | |
754 | .release = seq_release, | |
755 | }; | |
756 | ||
e09c8614 MH |
757 | /* Sum up total data length for dynamic arraies (strings) */ |
758 | static __kprobes int __get_data_size(struct trace_probe *tp, | |
759 | struct pt_regs *regs) | |
760 | { | |
761 | int i, ret = 0; | |
762 | u32 len; | |
763 | ||
764 | for (i = 0; i < tp->nr_args; i++) | |
765 | if (unlikely(tp->args[i].fetch_size.fn)) { | |
766 | call_fetch(&tp->args[i].fetch_size, regs, &len); | |
767 | ret += len; | |
768 | } | |
769 | ||
770 | return ret; | |
771 | } | |
772 | ||
773 | /* Store the value of each argument */ | |
774 | static __kprobes void store_trace_args(int ent_size, struct trace_probe *tp, | |
775 | struct pt_regs *regs, | |
776 | u8 *data, int maxlen) | |
777 | { | |
778 | int i; | |
779 | u32 end = tp->size; | |
780 | u32 *dl; /* Data (relative) location */ | |
781 | ||
782 | for (i = 0; i < tp->nr_args; i++) { | |
783 | if (unlikely(tp->args[i].fetch_size.fn)) { | |
784 | /* | |
785 | * First, we set the relative location and | |
786 | * maximum data length to *dl | |
787 | */ | |
788 | dl = (u32 *)(data + tp->args[i].offset); | |
789 | *dl = make_data_rloc(maxlen, end - tp->args[i].offset); | |
790 | /* Then try to fetch string or dynamic array data */ | |
791 | call_fetch(&tp->args[i].fetch, regs, dl); | |
792 | /* Reduce maximum length */ | |
793 | end += get_rloc_len(*dl); | |
794 | maxlen -= get_rloc_len(*dl); | |
795 | /* Trick here, convert data_rloc to data_loc */ | |
796 | *dl = convert_rloc_to_loc(*dl, | |
797 | ent_size + tp->args[i].offset); | |
798 | } else | |
799 | /* Just fetching data normally */ | |
800 | call_fetch(&tp->args[i].fetch, regs, | |
801 | data + tp->args[i].offset); | |
802 | } | |
803 | } | |
804 | ||
413d37d1 | 805 | /* Kprobe handler */ |
2b106aab | 806 | static __kprobes void |
41a7dd42 MH |
807 | __kprobe_trace_func(struct trace_probe *tp, struct pt_regs *regs, |
808 | struct ftrace_event_file *ftrace_file) | |
413d37d1 | 809 | { |
93ccae7a | 810 | struct kprobe_trace_entry_head *entry; |
413d37d1 | 811 | struct ring_buffer_event *event; |
8f8ffe24 | 812 | struct ring_buffer *buffer; |
e09c8614 | 813 | int size, dsize, pc; |
413d37d1 | 814 | unsigned long irq_flags; |
4263565d | 815 | struct ftrace_event_call *call = &tp->call; |
413d37d1 | 816 | |
41a7dd42 MH |
817 | WARN_ON(call != ftrace_file->event_call); |
818 | ||
b8820084 MH |
819 | if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags)) |
820 | return; | |
821 | ||
413d37d1 MH |
822 | local_save_flags(irq_flags); |
823 | pc = preempt_count(); | |
824 | ||
e09c8614 MH |
825 | dsize = __get_data_size(tp, regs); |
826 | size = sizeof(*entry) + tp->size + dsize; | |
413d37d1 | 827 | |
41a7dd42 MH |
828 | event = trace_event_buffer_lock_reserve(&buffer, ftrace_file, |
829 | call->event.type, | |
830 | size, irq_flags, pc); | |
413d37d1 | 831 | if (!event) |
1e12a4a7 | 832 | return; |
413d37d1 MH |
833 | |
834 | entry = ring_buffer_event_data(event); | |
2b106aab | 835 | entry->ip = (unsigned long)tp->rp.kp.addr; |
e09c8614 | 836 | store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize); |
413d37d1 | 837 | |
8f8ffe24 | 838 | if (!filter_current_check_discard(buffer, call, entry, event)) |
0d5c6e1c SR |
839 | trace_buffer_unlock_commit_regs(buffer, event, |
840 | irq_flags, pc, regs); | |
413d37d1 MH |
841 | } |
842 | ||
41a7dd42 MH |
843 | static __kprobes void |
844 | kprobe_trace_func(struct trace_probe *tp, struct pt_regs *regs) | |
845 | { | |
b04d52e3 | 846 | struct event_file_link *link; |
41a7dd42 | 847 | |
b04d52e3 ON |
848 | list_for_each_entry_rcu(link, &tp->files, list) |
849 | __kprobe_trace_func(tp, regs, link->file); | |
41a7dd42 MH |
850 | } |
851 | ||
413d37d1 | 852 | /* Kretprobe handler */ |
2b106aab | 853 | static __kprobes void |
41a7dd42 MH |
854 | __kretprobe_trace_func(struct trace_probe *tp, struct kretprobe_instance *ri, |
855 | struct pt_regs *regs, | |
856 | struct ftrace_event_file *ftrace_file) | |
413d37d1 | 857 | { |
93ccae7a | 858 | struct kretprobe_trace_entry_head *entry; |
413d37d1 | 859 | struct ring_buffer_event *event; |
8f8ffe24 | 860 | struct ring_buffer *buffer; |
e09c8614 | 861 | int size, pc, dsize; |
413d37d1 | 862 | unsigned long irq_flags; |
4263565d | 863 | struct ftrace_event_call *call = &tp->call; |
413d37d1 | 864 | |
41a7dd42 MH |
865 | WARN_ON(call != ftrace_file->event_call); |
866 | ||
b8820084 MH |
867 | if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags)) |
868 | return; | |
869 | ||
413d37d1 MH |
870 | local_save_flags(irq_flags); |
871 | pc = preempt_count(); | |
872 | ||
e09c8614 MH |
873 | dsize = __get_data_size(tp, regs); |
874 | size = sizeof(*entry) + tp->size + dsize; | |
413d37d1 | 875 | |
41a7dd42 MH |
876 | event = trace_event_buffer_lock_reserve(&buffer, ftrace_file, |
877 | call->event.type, | |
878 | size, irq_flags, pc); | |
413d37d1 | 879 | if (!event) |
1e12a4a7 | 880 | return; |
413d37d1 MH |
881 | |
882 | entry = ring_buffer_event_data(event); | |
4a846b44 | 883 | entry->func = (unsigned long)tp->rp.kp.addr; |
413d37d1 | 884 | entry->ret_ip = (unsigned long)ri->ret_addr; |
e09c8614 | 885 | store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize); |
413d37d1 | 886 | |
8f8ffe24 | 887 | if (!filter_current_check_discard(buffer, call, entry, event)) |
0d5c6e1c SR |
888 | trace_buffer_unlock_commit_regs(buffer, event, |
889 | irq_flags, pc, regs); | |
413d37d1 MH |
890 | } |
891 | ||
41a7dd42 MH |
892 | static __kprobes void |
893 | kretprobe_trace_func(struct trace_probe *tp, struct kretprobe_instance *ri, | |
894 | struct pt_regs *regs) | |
895 | { | |
b04d52e3 | 896 | struct event_file_link *link; |
41a7dd42 | 897 | |
b04d52e3 ON |
898 | list_for_each_entry_rcu(link, &tp->files, list) |
899 | __kretprobe_trace_func(tp, ri, regs, link->file); | |
41a7dd42 MH |
900 | } |
901 | ||
413d37d1 | 902 | /* Event entry printers */ |
b62fdd97 | 903 | static enum print_line_t |
a9a57763 SR |
904 | print_kprobe_event(struct trace_iterator *iter, int flags, |
905 | struct trace_event *event) | |
413d37d1 | 906 | { |
93ccae7a | 907 | struct kprobe_trace_entry_head *field; |
413d37d1 | 908 | struct trace_seq *s = &iter->seq; |
eca0d916 | 909 | struct trace_probe *tp; |
93ccae7a | 910 | u8 *data; |
413d37d1 MH |
911 | int i; |
912 | ||
93ccae7a | 913 | field = (struct kprobe_trace_entry_head *)iter->ent; |
80decc70 | 914 | tp = container_of(event, struct trace_probe, call.event); |
413d37d1 | 915 | |
6e9f23d1 MH |
916 | if (!trace_seq_printf(s, "%s: (", tp->call.name)) |
917 | goto partial; | |
918 | ||
413d37d1 MH |
919 | if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET)) |
920 | goto partial; | |
921 | ||
6e9f23d1 | 922 | if (!trace_seq_puts(s, ")")) |
413d37d1 MH |
923 | goto partial; |
924 | ||
93ccae7a MH |
925 | data = (u8 *)&field[1]; |
926 | for (i = 0; i < tp->nr_args; i++) | |
927 | if (!tp->args[i].type->print(s, tp->args[i].name, | |
e09c8614 | 928 | data + tp->args[i].offset, field)) |
413d37d1 MH |
929 | goto partial; |
930 | ||
931 | if (!trace_seq_puts(s, "\n")) | |
932 | goto partial; | |
933 | ||
934 | return TRACE_TYPE_HANDLED; | |
935 | partial: | |
936 | return TRACE_TYPE_PARTIAL_LINE; | |
937 | } | |
938 | ||
b62fdd97 | 939 | static enum print_line_t |
a9a57763 SR |
940 | print_kretprobe_event(struct trace_iterator *iter, int flags, |
941 | struct trace_event *event) | |
413d37d1 | 942 | { |
93ccae7a | 943 | struct kretprobe_trace_entry_head *field; |
413d37d1 | 944 | struct trace_seq *s = &iter->seq; |
eca0d916 | 945 | struct trace_probe *tp; |
93ccae7a | 946 | u8 *data; |
413d37d1 MH |
947 | int i; |
948 | ||
93ccae7a | 949 | field = (struct kretprobe_trace_entry_head *)iter->ent; |
80decc70 | 950 | tp = container_of(event, struct trace_probe, call.event); |
413d37d1 | 951 | |
6e9f23d1 MH |
952 | if (!trace_seq_printf(s, "%s: (", tp->call.name)) |
953 | goto partial; | |
954 | ||
413d37d1 MH |
955 | if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET)) |
956 | goto partial; | |
957 | ||
958 | if (!trace_seq_puts(s, " <- ")) | |
959 | goto partial; | |
960 | ||
961 | if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET)) | |
962 | goto partial; | |
963 | ||
6e9f23d1 | 964 | if (!trace_seq_puts(s, ")")) |
413d37d1 MH |
965 | goto partial; |
966 | ||
93ccae7a MH |
967 | data = (u8 *)&field[1]; |
968 | for (i = 0; i < tp->nr_args; i++) | |
969 | if (!tp->args[i].type->print(s, tp->args[i].name, | |
e09c8614 | 970 | data + tp->args[i].offset, field)) |
413d37d1 MH |
971 | goto partial; |
972 | ||
973 | if (!trace_seq_puts(s, "\n")) | |
974 | goto partial; | |
975 | ||
976 | return TRACE_TYPE_HANDLED; | |
977 | partial: | |
978 | return TRACE_TYPE_PARTIAL_LINE; | |
979 | } | |
980 | ||
413d37d1 MH |
981 | |
982 | static int kprobe_event_define_fields(struct ftrace_event_call *event_call) | |
983 | { | |
984 | int ret, i; | |
93ccae7a | 985 | struct kprobe_trace_entry_head field; |
413d37d1 MH |
986 | struct trace_probe *tp = (struct trace_probe *)event_call->data; |
987 | ||
a703d946 | 988 | DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0); |
eca0d916 | 989 | /* Set argument names as fields */ |
93ccae7a | 990 | for (i = 0; i < tp->nr_args; i++) { |
e09c8614 | 991 | ret = trace_define_field(event_call, tp->args[i].type->fmttype, |
93ccae7a MH |
992 | tp->args[i].name, |
993 | sizeof(field) + tp->args[i].offset, | |
994 | tp->args[i].type->size, | |
995 | tp->args[i].type->is_signed, | |
996 | FILTER_OTHER); | |
997 | if (ret) | |
998 | return ret; | |
999 | } | |
413d37d1 MH |
1000 | return 0; |
1001 | } | |
1002 | ||
1003 | static int kretprobe_event_define_fields(struct ftrace_event_call *event_call) | |
1004 | { | |
1005 | int ret, i; | |
93ccae7a | 1006 | struct kretprobe_trace_entry_head field; |
413d37d1 MH |
1007 | struct trace_probe *tp = (struct trace_probe *)event_call->data; |
1008 | ||
a703d946 MH |
1009 | DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0); |
1010 | DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0); | |
eca0d916 | 1011 | /* Set argument names as fields */ |
93ccae7a | 1012 | for (i = 0; i < tp->nr_args; i++) { |
e09c8614 | 1013 | ret = trace_define_field(event_call, tp->args[i].type->fmttype, |
93ccae7a MH |
1014 | tp->args[i].name, |
1015 | sizeof(field) + tp->args[i].offset, | |
1016 | tp->args[i].type->size, | |
1017 | tp->args[i].type->is_signed, | |
1018 | FILTER_OTHER); | |
1019 | if (ret) | |
1020 | return ret; | |
1021 | } | |
413d37d1 MH |
1022 | return 0; |
1023 | } | |
1024 | ||
a342a028 LJ |
1025 | static int __set_print_fmt(struct trace_probe *tp, char *buf, int len) |
1026 | { | |
1027 | int i; | |
1028 | int pos = 0; | |
1029 | ||
1030 | const char *fmt, *arg; | |
1031 | ||
7143f168 | 1032 | if (!trace_probe_is_return(tp)) { |
a342a028 LJ |
1033 | fmt = "(%lx)"; |
1034 | arg = "REC->" FIELD_STRING_IP; | |
1035 | } else { | |
1036 | fmt = "(%lx <- %lx)"; | |
1037 | arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP; | |
1038 | } | |
1039 | ||
1040 | /* When len=0, we just calculate the needed length */ | |
1041 | #define LEN_OR_ZERO (len ? len - pos : 0) | |
1042 | ||
1043 | pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt); | |
1044 | ||
1045 | for (i = 0; i < tp->nr_args; i++) { | |
93ccae7a MH |
1046 | pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%s", |
1047 | tp->args[i].name, tp->args[i].type->fmt); | |
a342a028 LJ |
1048 | } |
1049 | ||
1050 | pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg); | |
1051 | ||
1052 | for (i = 0; i < tp->nr_args; i++) { | |
e09c8614 MH |
1053 | if (strcmp(tp->args[i].type->name, "string") == 0) |
1054 | pos += snprintf(buf + pos, LEN_OR_ZERO, | |
1055 | ", __get_str(%s)", | |
1056 | tp->args[i].name); | |
1057 | else | |
1058 | pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s", | |
1059 | tp->args[i].name); | |
a342a028 LJ |
1060 | } |
1061 | ||
1062 | #undef LEN_OR_ZERO | |
1063 | ||
1064 | /* return the length of print_fmt */ | |
1065 | return pos; | |
1066 | } | |
1067 | ||
1068 | static int set_print_fmt(struct trace_probe *tp) | |
1069 | { | |
1070 | int len; | |
1071 | char *print_fmt; | |
1072 | ||
1073 | /* First: called with 0 length to calculate the needed length */ | |
1074 | len = __set_print_fmt(tp, NULL, 0); | |
1075 | print_fmt = kmalloc(len + 1, GFP_KERNEL); | |
1076 | if (!print_fmt) | |
1077 | return -ENOMEM; | |
1078 | ||
1079 | /* Second: actually write the @print_fmt */ | |
1080 | __set_print_fmt(tp, print_fmt, len + 1); | |
1081 | tp->call.print_fmt = print_fmt; | |
1082 | ||
1083 | return 0; | |
1084 | } | |
1085 | ||
07b139c8 | 1086 | #ifdef CONFIG_PERF_EVENTS |
e08d1c65 MH |
1087 | |
1088 | /* Kprobe profile handler */ | |
2b106aab MH |
1089 | static __kprobes void |
1090 | kprobe_perf_func(struct trace_probe *tp, struct pt_regs *regs) | |
e08d1c65 | 1091 | { |
e08d1c65 | 1092 | struct ftrace_event_call *call = &tp->call; |
93ccae7a | 1093 | struct kprobe_trace_entry_head *entry; |
1c024eca | 1094 | struct hlist_head *head; |
e09c8614 | 1095 | int size, __size, dsize; |
4ed7c92d | 1096 | int rctx; |
e08d1c65 | 1097 | |
288e984e ON |
1098 | head = this_cpu_ptr(call->perf_events); |
1099 | if (hlist_empty(head)) | |
1100 | return; | |
1101 | ||
e09c8614 MH |
1102 | dsize = __get_data_size(tp, regs); |
1103 | __size = sizeof(*entry) + tp->size + dsize; | |
74ebb63e MH |
1104 | size = ALIGN(__size + sizeof(u32), sizeof(u64)); |
1105 | size -= sizeof(u32); | |
ce71b9df | 1106 | |
ff5f149b | 1107 | entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx); |
430ad5a6 | 1108 | if (!entry) |
1e12a4a7 | 1109 | return; |
a1a138d0 | 1110 | |
2b106aab | 1111 | entry->ip = (unsigned long)tp->rp.kp.addr; |
e09c8614 MH |
1112 | memset(&entry[1], 0, dsize); |
1113 | store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize); | |
cf6735a4 | 1114 | perf_trace_buf_submit(entry, size, rctx, 0, 1, regs, head, NULL); |
e08d1c65 MH |
1115 | } |
1116 | ||
1117 | /* Kretprobe profile handler */ | |
2b106aab MH |
1118 | static __kprobes void |
1119 | kretprobe_perf_func(struct trace_probe *tp, struct kretprobe_instance *ri, | |
1120 | struct pt_regs *regs) | |
e08d1c65 | 1121 | { |
e08d1c65 | 1122 | struct ftrace_event_call *call = &tp->call; |
93ccae7a | 1123 | struct kretprobe_trace_entry_head *entry; |
1c024eca | 1124 | struct hlist_head *head; |
e09c8614 | 1125 | int size, __size, dsize; |
4ed7c92d | 1126 | int rctx; |
e08d1c65 | 1127 | |
288e984e ON |
1128 | head = this_cpu_ptr(call->perf_events); |
1129 | if (hlist_empty(head)) | |
1130 | return; | |
1131 | ||
e09c8614 MH |
1132 | dsize = __get_data_size(tp, regs); |
1133 | __size = sizeof(*entry) + tp->size + dsize; | |
74ebb63e MH |
1134 | size = ALIGN(__size + sizeof(u32), sizeof(u64)); |
1135 | size -= sizeof(u32); | |
444a2a3b | 1136 | |
ff5f149b | 1137 | entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx); |
430ad5a6 | 1138 | if (!entry) |
1e12a4a7 | 1139 | return; |
e08d1c65 | 1140 | |
a1a138d0 MH |
1141 | entry->func = (unsigned long)tp->rp.kp.addr; |
1142 | entry->ret_ip = (unsigned long)ri->ret_addr; | |
e09c8614 | 1143 | store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize); |
cf6735a4 | 1144 | perf_trace_buf_submit(entry, size, rctx, 0, 1, regs, head, NULL); |
e08d1c65 | 1145 | } |
07b139c8 | 1146 | #endif /* CONFIG_PERF_EVENTS */ |
50d78056 | 1147 | |
3fe3d619 ON |
1148 | /* |
1149 | * called by perf_trace_init() or __ftrace_set_clr_event() under event_mutex. | |
1150 | * | |
1151 | * kprobe_trace_self_tests_init() does enable_trace_probe/disable_trace_probe | |
1152 | * lockless, but we can't race with this __init function. | |
1153 | */ | |
2239291a | 1154 | static __kprobes |
ceec0b6f JO |
1155 | int kprobe_register(struct ftrace_event_call *event, |
1156 | enum trace_reg type, void *data) | |
2239291a | 1157 | { |
1538f888 | 1158 | struct trace_probe *tp = (struct trace_probe *)event->data; |
41a7dd42 | 1159 | struct ftrace_event_file *file = data; |
1538f888 | 1160 | |
2239291a SR |
1161 | switch (type) { |
1162 | case TRACE_REG_REGISTER: | |
41a7dd42 | 1163 | return enable_trace_probe(tp, file); |
2239291a | 1164 | case TRACE_REG_UNREGISTER: |
41a7dd42 | 1165 | return disable_trace_probe(tp, file); |
2239291a SR |
1166 | |
1167 | #ifdef CONFIG_PERF_EVENTS | |
1168 | case TRACE_REG_PERF_REGISTER: | |
41a7dd42 | 1169 | return enable_trace_probe(tp, NULL); |
2239291a | 1170 | case TRACE_REG_PERF_UNREGISTER: |
41a7dd42 | 1171 | return disable_trace_probe(tp, NULL); |
ceec0b6f JO |
1172 | case TRACE_REG_PERF_OPEN: |
1173 | case TRACE_REG_PERF_CLOSE: | |
489c75c3 JO |
1174 | case TRACE_REG_PERF_ADD: |
1175 | case TRACE_REG_PERF_DEL: | |
ceec0b6f | 1176 | return 0; |
2239291a SR |
1177 | #endif |
1178 | } | |
1179 | return 0; | |
1180 | } | |
50d78056 MH |
1181 | |
1182 | static __kprobes | |
1183 | int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs) | |
1184 | { | |
1185 | struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp); | |
e08d1c65 | 1186 | |
48182bd2 MH |
1187 | tp->nhit++; |
1188 | ||
50d78056 | 1189 | if (tp->flags & TP_FLAG_TRACE) |
2b106aab | 1190 | kprobe_trace_func(tp, regs); |
07b139c8 | 1191 | #ifdef CONFIG_PERF_EVENTS |
50d78056 | 1192 | if (tp->flags & TP_FLAG_PROFILE) |
2b106aab | 1193 | kprobe_perf_func(tp, regs); |
07b139c8 | 1194 | #endif |
50d78056 MH |
1195 | return 0; /* We don't tweek kernel, so just return 0 */ |
1196 | } | |
1197 | ||
1198 | static __kprobes | |
1199 | int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs) | |
1200 | { | |
1201 | struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp); | |
1202 | ||
48182bd2 MH |
1203 | tp->nhit++; |
1204 | ||
50d78056 | 1205 | if (tp->flags & TP_FLAG_TRACE) |
2b106aab | 1206 | kretprobe_trace_func(tp, ri, regs); |
07b139c8 | 1207 | #ifdef CONFIG_PERF_EVENTS |
50d78056 | 1208 | if (tp->flags & TP_FLAG_PROFILE) |
2b106aab | 1209 | kretprobe_perf_func(tp, ri, regs); |
07b139c8 | 1210 | #endif |
50d78056 MH |
1211 | return 0; /* We don't tweek kernel, so just return 0 */ |
1212 | } | |
e08d1c65 | 1213 | |
a9a57763 SR |
1214 | static struct trace_event_functions kretprobe_funcs = { |
1215 | .trace = print_kretprobe_event | |
1216 | }; | |
1217 | ||
1218 | static struct trace_event_functions kprobe_funcs = { | |
1219 | .trace = print_kprobe_event | |
1220 | }; | |
1221 | ||
413d37d1 MH |
1222 | static int register_probe_event(struct trace_probe *tp) |
1223 | { | |
1224 | struct ftrace_event_call *call = &tp->call; | |
1225 | int ret; | |
1226 | ||
1227 | /* Initialize ftrace_event_call */ | |
ffb9f995 | 1228 | INIT_LIST_HEAD(&call->class->fields); |
7143f168 | 1229 | if (trace_probe_is_return(tp)) { |
80decc70 | 1230 | call->event.funcs = &kretprobe_funcs; |
2e33af02 | 1231 | call->class->define_fields = kretprobe_event_define_fields; |
413d37d1 | 1232 | } else { |
80decc70 | 1233 | call->event.funcs = &kprobe_funcs; |
2e33af02 | 1234 | call->class->define_fields = kprobe_event_define_fields; |
413d37d1 | 1235 | } |
a342a028 LJ |
1236 | if (set_print_fmt(tp) < 0) |
1237 | return -ENOMEM; | |
32c0edae SR |
1238 | ret = register_ftrace_event(&call->event); |
1239 | if (!ret) { | |
a342a028 | 1240 | kfree(call->print_fmt); |
ff50d991 | 1241 | return -ENODEV; |
a342a028 | 1242 | } |
553552ce | 1243 | call->flags = 0; |
2239291a | 1244 | call->class->reg = kprobe_register; |
413d37d1 MH |
1245 | call->data = tp; |
1246 | ret = trace_add_event_call(call); | |
ff50d991 | 1247 | if (ret) { |
413d37d1 | 1248 | pr_info("Failed to register kprobe event: %s\n", call->name); |
a342a028 | 1249 | kfree(call->print_fmt); |
80decc70 | 1250 | unregister_ftrace_event(&call->event); |
ff50d991 | 1251 | } |
413d37d1 MH |
1252 | return ret; |
1253 | } | |
1254 | ||
40c32592 | 1255 | static int unregister_probe_event(struct trace_probe *tp) |
413d37d1 | 1256 | { |
40c32592 SRRH |
1257 | int ret; |
1258 | ||
ff50d991 | 1259 | /* tp->event is unregistered in trace_remove_event_call() */ |
40c32592 SRRH |
1260 | ret = trace_remove_event_call(&tp->call); |
1261 | if (!ret) | |
1262 | kfree(tp->call.print_fmt); | |
1263 | return ret; | |
413d37d1 MH |
1264 | } |
1265 | ||
25985edc | 1266 | /* Make a debugfs interface for controlling probe points */ |
413d37d1 MH |
1267 | static __init int init_kprobe_trace(void) |
1268 | { | |
1269 | struct dentry *d_tracer; | |
1270 | struct dentry *entry; | |
413d37d1 | 1271 | |
61424318 MH |
1272 | if (register_module_notifier(&trace_probe_module_nb)) |
1273 | return -EINVAL; | |
1274 | ||
413d37d1 MH |
1275 | d_tracer = tracing_init_dentry(); |
1276 | if (!d_tracer) | |
1277 | return 0; | |
1278 | ||
1279 | entry = debugfs_create_file("kprobe_events", 0644, d_tracer, | |
1280 | NULL, &kprobe_events_ops); | |
1281 | ||
cd7e7bd5 | 1282 | /* Event list interface */ |
413d37d1 MH |
1283 | if (!entry) |
1284 | pr_warning("Could not create debugfs " | |
1285 | "'kprobe_events' entry\n"); | |
cd7e7bd5 MH |
1286 | |
1287 | /* Profile interface */ | |
1288 | entry = debugfs_create_file("kprobe_profile", 0444, d_tracer, | |
1289 | NULL, &kprobe_profile_ops); | |
1290 | ||
1291 | if (!entry) | |
1292 | pr_warning("Could not create debugfs " | |
1293 | "'kprobe_profile' entry\n"); | |
413d37d1 MH |
1294 | return 0; |
1295 | } | |
1296 | fs_initcall(init_kprobe_trace); | |
1297 | ||
1298 | ||
1299 | #ifdef CONFIG_FTRACE_STARTUP_TEST | |
1300 | ||
265a5b7e SR |
1301 | /* |
1302 | * The "__used" keeps gcc from removing the function symbol | |
1303 | * from the kallsyms table. | |
1304 | */ | |
1305 | static __used int kprobe_trace_selftest_target(int a1, int a2, int a3, | |
1306 | int a4, int a5, int a6) | |
413d37d1 MH |
1307 | { |
1308 | return a1 + a2 + a3 + a4 + a5 + a6; | |
1309 | } | |
1310 | ||
41a7dd42 MH |
1311 | static struct ftrace_event_file * |
1312 | find_trace_probe_file(struct trace_probe *tp, struct trace_array *tr) | |
1313 | { | |
1314 | struct ftrace_event_file *file; | |
1315 | ||
1316 | list_for_each_entry(file, &tr->events, list) | |
1317 | if (file->event_call == &tp->call) | |
1318 | return file; | |
1319 | ||
1320 | return NULL; | |
1321 | } | |
1322 | ||
3fe3d619 ON |
1323 | /* |
1324 | * Nobody but us can call enable_trace_probe/disable_trace_probe at this | |
1325 | * stage, we can do this lockless. | |
1326 | */ | |
413d37d1 MH |
1327 | static __init int kprobe_trace_self_tests_init(void) |
1328 | { | |
231e36f4 | 1329 | int ret, warn = 0; |
413d37d1 | 1330 | int (*target)(int, int, int, int, int, int); |
231e36f4 | 1331 | struct trace_probe *tp; |
41a7dd42 | 1332 | struct ftrace_event_file *file; |
413d37d1 MH |
1333 | |
1334 | target = kprobe_trace_selftest_target; | |
1335 | ||
1336 | pr_info("Testing kprobe tracing: "); | |
1337 | ||
8ab83f56 SD |
1338 | ret = traceprobe_command("p:testprobe kprobe_trace_selftest_target " |
1339 | "$stack $stack0 +0($stack)", | |
1340 | create_trace_probe); | |
231e36f4 | 1341 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1342 | pr_warn("error on probing function entry.\n"); |
231e36f4 MH |
1343 | warn++; |
1344 | } else { | |
1345 | /* Enable trace point */ | |
7143f168 | 1346 | tp = find_trace_probe("testprobe", KPROBE_EVENT_SYSTEM); |
231e36f4 | 1347 | if (WARN_ON_ONCE(tp == NULL)) { |
41a7dd42 | 1348 | pr_warn("error on getting new probe.\n"); |
231e36f4 | 1349 | warn++; |
41a7dd42 MH |
1350 | } else { |
1351 | file = find_trace_probe_file(tp, top_trace_array()); | |
1352 | if (WARN_ON_ONCE(file == NULL)) { | |
1353 | pr_warn("error on getting probe file.\n"); | |
1354 | warn++; | |
1355 | } else | |
1356 | enable_trace_probe(tp, file); | |
1357 | } | |
231e36f4 | 1358 | } |
413d37d1 | 1359 | |
8ab83f56 SD |
1360 | ret = traceprobe_command("r:testprobe2 kprobe_trace_selftest_target " |
1361 | "$retval", create_trace_probe); | |
231e36f4 | 1362 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1363 | pr_warn("error on probing function return.\n"); |
231e36f4 MH |
1364 | warn++; |
1365 | } else { | |
1366 | /* Enable trace point */ | |
7143f168 | 1367 | tp = find_trace_probe("testprobe2", KPROBE_EVENT_SYSTEM); |
231e36f4 | 1368 | if (WARN_ON_ONCE(tp == NULL)) { |
41a7dd42 | 1369 | pr_warn("error on getting 2nd new probe.\n"); |
231e36f4 | 1370 | warn++; |
41a7dd42 MH |
1371 | } else { |
1372 | file = find_trace_probe_file(tp, top_trace_array()); | |
1373 | if (WARN_ON_ONCE(file == NULL)) { | |
1374 | pr_warn("error on getting probe file.\n"); | |
1375 | warn++; | |
1376 | } else | |
1377 | enable_trace_probe(tp, file); | |
1378 | } | |
231e36f4 MH |
1379 | } |
1380 | ||
1381 | if (warn) | |
1382 | goto end; | |
413d37d1 MH |
1383 | |
1384 | ret = target(1, 2, 3, 4, 5, 6); | |
1385 | ||
02ca1521 MH |
1386 | /* Disable trace points before removing it */ |
1387 | tp = find_trace_probe("testprobe", KPROBE_EVENT_SYSTEM); | |
1388 | if (WARN_ON_ONCE(tp == NULL)) { | |
41a7dd42 | 1389 | pr_warn("error on getting test probe.\n"); |
02ca1521 | 1390 | warn++; |
41a7dd42 MH |
1391 | } else { |
1392 | file = find_trace_probe_file(tp, top_trace_array()); | |
1393 | if (WARN_ON_ONCE(file == NULL)) { | |
1394 | pr_warn("error on getting probe file.\n"); | |
1395 | warn++; | |
1396 | } else | |
1397 | disable_trace_probe(tp, file); | |
1398 | } | |
02ca1521 MH |
1399 | |
1400 | tp = find_trace_probe("testprobe2", KPROBE_EVENT_SYSTEM); | |
1401 | if (WARN_ON_ONCE(tp == NULL)) { | |
41a7dd42 | 1402 | pr_warn("error on getting 2nd test probe.\n"); |
02ca1521 | 1403 | warn++; |
41a7dd42 MH |
1404 | } else { |
1405 | file = find_trace_probe_file(tp, top_trace_array()); | |
1406 | if (WARN_ON_ONCE(file == NULL)) { | |
1407 | pr_warn("error on getting probe file.\n"); | |
1408 | warn++; | |
1409 | } else | |
1410 | disable_trace_probe(tp, file); | |
1411 | } | |
02ca1521 | 1412 | |
8ab83f56 | 1413 | ret = traceprobe_command("-:testprobe", create_trace_probe); |
231e36f4 | 1414 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1415 | pr_warn("error on deleting a probe.\n"); |
231e36f4 MH |
1416 | warn++; |
1417 | } | |
1418 | ||
8ab83f56 | 1419 | ret = traceprobe_command("-:testprobe2", create_trace_probe); |
231e36f4 | 1420 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1421 | pr_warn("error on deleting a probe.\n"); |
231e36f4 MH |
1422 | warn++; |
1423 | } | |
413d37d1 | 1424 | |
231e36f4 | 1425 | end: |
7143f168 | 1426 | release_all_trace_probes(); |
231e36f4 MH |
1427 | if (warn) |
1428 | pr_cont("NG: Some tests are failed. Please check them.\n"); | |
1429 | else | |
1430 | pr_cont("OK\n"); | |
413d37d1 MH |
1431 | return 0; |
1432 | } | |
1433 | ||
1434 | late_initcall(kprobe_trace_self_tests_init); | |
1435 | ||
1436 | #endif |