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