Commit | Line | Data |
---|---|---|
413d37d1 | 1 | /* |
77b44d1b | 2 | * Kprobes-based tracing events |
413d37d1 MH |
3 | * |
4 | * Created by Masami Hiramatsu <mhiramat@redhat.com> | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program; if not, write to the Free Software | |
17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
18 | */ | |
19 | ||
20 | #include <linux/module.h> | |
21 | #include <linux/uaccess.h> | |
413d37d1 | 22 | |
8ab83f56 | 23 | #include "trace_probe.h" |
1ff511e3 | 24 | |
8ab83f56 | 25 | #define KPROBE_EVENT_SYSTEM "kprobes" |
e09c8614 | 26 | |
413d37d1 | 27 | /** |
77b44d1b | 28 | * Kprobe event core functions |
413d37d1 | 29 | */ |
413d37d1 MH |
30 | struct trace_probe { |
31 | struct list_head list; | |
4a846b44 | 32 | struct kretprobe rp; /* Use rp.kp for kprobe use */ |
cd7e7bd5 | 33 | unsigned long nhit; |
50d78056 | 34 | unsigned int flags; /* For TP_FLAG_* */ |
413d37d1 | 35 | const char *symbol; /* symbol name */ |
2239291a | 36 | struct ftrace_event_class class; |
413d37d1 | 37 | struct ftrace_event_call call; |
3d1fc7b0 | 38 | struct ftrace_event_file * __rcu *files; |
93ccae7a | 39 | ssize_t size; /* trace entry size */ |
a82378d8 | 40 | unsigned int nr_args; |
eca0d916 | 41 | struct probe_arg args[]; |
413d37d1 MH |
42 | }; |
43 | ||
a82378d8 MH |
44 | #define SIZEOF_TRACE_PROBE(n) \ |
45 | (offsetof(struct trace_probe, args) + \ | |
eca0d916 | 46 | (sizeof(struct probe_arg) * (n))) |
a82378d8 | 47 | |
93ccae7a | 48 | |
db02038f | 49 | static __kprobes bool trace_probe_is_return(struct trace_probe *tp) |
413d37d1 | 50 | { |
4a846b44 | 51 | return tp->rp.handler != NULL; |
413d37d1 MH |
52 | } |
53 | ||
7143f168 | 54 | static __kprobes const char *trace_probe_symbol(struct trace_probe *tp) |
413d37d1 MH |
55 | { |
56 | return tp->symbol ? tp->symbol : "unknown"; | |
57 | } | |
58 | ||
61424318 MH |
59 | static __kprobes unsigned long trace_probe_offset(struct trace_probe *tp) |
60 | { | |
61 | return tp->rp.kp.offset; | |
62 | } | |
63 | ||
64 | static __kprobes bool trace_probe_is_enabled(struct trace_probe *tp) | |
65 | { | |
66 | return !!(tp->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE)); | |
67 | } | |
68 | ||
69 | static __kprobes bool trace_probe_is_registered(struct trace_probe *tp) | |
70 | { | |
71 | return !!(tp->flags & TP_FLAG_REGISTERED); | |
72 | } | |
73 | ||
74 | static __kprobes bool trace_probe_has_gone(struct trace_probe *tp) | |
75 | { | |
76 | return !!(kprobe_gone(&tp->rp.kp)); | |
77 | } | |
78 | ||
79 | static __kprobes bool trace_probe_within_module(struct trace_probe *tp, | |
80 | struct module *mod) | |
81 | { | |
82 | int len = strlen(mod->name); | |
83 | const char *name = trace_probe_symbol(tp); | |
84 | return strncmp(mod->name, name, len) == 0 && name[len] == ':'; | |
85 | } | |
86 | ||
87 | static __kprobes bool trace_probe_is_on_module(struct trace_probe *tp) | |
88 | { | |
89 | return !!strchr(trace_probe_symbol(tp), ':'); | |
90 | } | |
91 | ||
413d37d1 MH |
92 | static int register_probe_event(struct trace_probe *tp); |
93 | static void unregister_probe_event(struct trace_probe *tp); | |
94 | ||
95 | static DEFINE_MUTEX(probe_lock); | |
96 | static LIST_HEAD(probe_list); | |
97 | ||
50d78056 MH |
98 | static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs); |
99 | static int kretprobe_dispatcher(struct kretprobe_instance *ri, | |
100 | struct pt_regs *regs); | |
101 | ||
4a846b44 MH |
102 | /* |
103 | * Allocate new trace_probe and initialize it (including kprobes). | |
104 | */ | |
f52487e9 MH |
105 | static struct trace_probe *alloc_trace_probe(const char *group, |
106 | const char *event, | |
4a846b44 MH |
107 | void *addr, |
108 | const char *symbol, | |
109 | unsigned long offs, | |
3a6b7666 | 110 | int nargs, bool is_return) |
413d37d1 MH |
111 | { |
112 | struct trace_probe *tp; | |
6f3cf440 | 113 | int ret = -ENOMEM; |
413d37d1 | 114 | |
a82378d8 | 115 | tp = kzalloc(SIZEOF_TRACE_PROBE(nargs), GFP_KERNEL); |
413d37d1 | 116 | if (!tp) |
6f3cf440 | 117 | return ERR_PTR(ret); |
413d37d1 MH |
118 | |
119 | if (symbol) { | |
120 | tp->symbol = kstrdup(symbol, GFP_KERNEL); | |
121 | if (!tp->symbol) | |
122 | goto error; | |
4a846b44 MH |
123 | tp->rp.kp.symbol_name = tp->symbol; |
124 | tp->rp.kp.offset = offs; | |
125 | } else | |
126 | tp->rp.kp.addr = addr; | |
127 | ||
128 | if (is_return) | |
50d78056 | 129 | tp->rp.handler = kretprobe_dispatcher; |
4a846b44 | 130 | else |
50d78056 | 131 | tp->rp.kp.pre_handler = kprobe_dispatcher; |
4a846b44 | 132 | |
da34634f | 133 | if (!event || !is_good_name(event)) { |
6f3cf440 | 134 | ret = -EINVAL; |
4263565d | 135 | goto error; |
6f3cf440 MH |
136 | } |
137 | ||
2239291a | 138 | tp->call.class = &tp->class; |
4263565d MH |
139 | tp->call.name = kstrdup(event, GFP_KERNEL); |
140 | if (!tp->call.name) | |
141 | goto error; | |
413d37d1 | 142 | |
da34634f | 143 | if (!group || !is_good_name(group)) { |
6f3cf440 | 144 | ret = -EINVAL; |
f52487e9 | 145 | goto error; |
6f3cf440 MH |
146 | } |
147 | ||
2239291a SR |
148 | tp->class.system = kstrdup(group, GFP_KERNEL); |
149 | if (!tp->class.system) | |
f52487e9 MH |
150 | goto error; |
151 | ||
413d37d1 MH |
152 | INIT_LIST_HEAD(&tp->list); |
153 | return tp; | |
154 | error: | |
f52487e9 | 155 | kfree(tp->call.name); |
413d37d1 MH |
156 | kfree(tp->symbol); |
157 | kfree(tp); | |
6f3cf440 | 158 | return ERR_PTR(ret); |
413d37d1 MH |
159 | } |
160 | ||
161 | static void free_trace_probe(struct trace_probe *tp) | |
162 | { | |
163 | int i; | |
164 | ||
165 | for (i = 0; i < tp->nr_args; i++) | |
8ab83f56 | 166 | traceprobe_free_probe_arg(&tp->args[i]); |
413d37d1 | 167 | |
8f082018 | 168 | kfree(tp->call.class->system); |
413d37d1 MH |
169 | kfree(tp->call.name); |
170 | kfree(tp->symbol); | |
171 | kfree(tp); | |
172 | } | |
173 | ||
7143f168 | 174 | static struct trace_probe *find_trace_probe(const char *event, |
dd004c47 | 175 | const char *group) |
413d37d1 MH |
176 | { |
177 | struct trace_probe *tp; | |
178 | ||
179 | list_for_each_entry(tp, &probe_list, list) | |
dd004c47 | 180 | if (strcmp(tp->call.name, event) == 0 && |
8f082018 | 181 | strcmp(tp->call.class->system, group) == 0) |
413d37d1 MH |
182 | return tp; |
183 | return NULL; | |
184 | } | |
185 | ||
3fe3d619 ON |
186 | /* |
187 | * This and enable_trace_probe/disable_trace_probe rely on event_mutex | |
188 | * held by the caller, __ftrace_set_clr_event(). | |
189 | */ | |
41a7dd42 MH |
190 | static int trace_probe_nr_files(struct trace_probe *tp) |
191 | { | |
3fe3d619 | 192 | struct ftrace_event_file **file = rcu_dereference_raw(tp->files); |
41a7dd42 MH |
193 | int ret = 0; |
194 | ||
195 | if (file) | |
196 | while (*(file++)) | |
197 | ret++; | |
198 | ||
199 | return ret; | |
200 | } | |
201 | ||
41a7dd42 MH |
202 | /* |
203 | * Enable trace_probe | |
204 | * if the file is NULL, enable "perf" handler, or enable "trace" handler. | |
205 | */ | |
206 | static int | |
207 | enable_trace_probe(struct trace_probe *tp, struct ftrace_event_file *file) | |
1538f888 MH |
208 | { |
209 | int ret = 0; | |
210 | ||
41a7dd42 | 211 | if (file) { |
c02c7e65 | 212 | struct ftrace_event_file **new, **old; |
41a7dd42 MH |
213 | int n = trace_probe_nr_files(tp); |
214 | ||
c02c7e65 | 215 | old = rcu_dereference_raw(tp->files); |
41a7dd42 MH |
216 | /* 1 is for new one and 1 is for stopper */ |
217 | new = kzalloc((n + 2) * sizeof(struct ftrace_event_file *), | |
218 | GFP_KERNEL); | |
219 | if (!new) { | |
220 | ret = -ENOMEM; | |
3fe3d619 | 221 | goto out; |
41a7dd42 MH |
222 | } |
223 | memcpy(new, old, n * sizeof(struct ftrace_event_file *)); | |
224 | new[n] = file; | |
225 | /* The last one keeps a NULL */ | |
226 | ||
227 | rcu_assign_pointer(tp->files, new); | |
228 | tp->flags |= TP_FLAG_TRACE; | |
229 | ||
230 | if (old) { | |
231 | /* Make sure the probe is done with old files */ | |
232 | synchronize_sched(); | |
233 | kfree(old); | |
234 | } | |
235 | } else | |
236 | tp->flags |= TP_FLAG_PROFILE; | |
237 | ||
195a84d9 | 238 | if (trace_probe_is_registered(tp) && !trace_probe_has_gone(tp)) { |
1538f888 MH |
239 | if (trace_probe_is_return(tp)) |
240 | ret = enable_kretprobe(&tp->rp); | |
241 | else | |
242 | ret = enable_kprobe(&tp->rp.kp); | |
243 | } | |
3fe3d619 | 244 | out: |
1538f888 MH |
245 | return ret; |
246 | } | |
247 | ||
41a7dd42 MH |
248 | static int |
249 | trace_probe_file_index(struct trace_probe *tp, struct ftrace_event_file *file) | |
250 | { | |
c02c7e65 | 251 | struct ftrace_event_file **files; |
41a7dd42 MH |
252 | int i; |
253 | ||
c02c7e65 MH |
254 | /* |
255 | * Since all tp->files updater is protected by probe_enable_lock, | |
256 | * we don't need to lock an rcu_read_lock. | |
257 | */ | |
258 | files = rcu_dereference_raw(tp->files); | |
259 | if (files) { | |
260 | for (i = 0; files[i]; i++) | |
261 | if (files[i] == file) | |
41a7dd42 MH |
262 | return i; |
263 | } | |
264 | ||
265 | return -1; | |
266 | } | |
267 | ||
268 | /* | |
269 | * Disable trace_probe | |
270 | * if the file is NULL, disable "perf" handler, or disable "trace" handler. | |
271 | */ | |
272 | static int | |
273 | disable_trace_probe(struct trace_probe *tp, struct ftrace_event_file *file) | |
1538f888 | 274 | { |
41a7dd42 MH |
275 | int ret = 0; |
276 | ||
41a7dd42 | 277 | if (file) { |
c02c7e65 | 278 | struct ftrace_event_file **new, **old; |
41a7dd42 MH |
279 | int n = trace_probe_nr_files(tp); |
280 | int i, j; | |
281 | ||
c02c7e65 | 282 | old = rcu_dereference_raw(tp->files); |
41a7dd42 MH |
283 | if (n == 0 || trace_probe_file_index(tp, file) < 0) { |
284 | ret = -EINVAL; | |
3fe3d619 | 285 | goto out; |
41a7dd42 MH |
286 | } |
287 | ||
288 | if (n == 1) { /* Remove the last file */ | |
289 | tp->flags &= ~TP_FLAG_TRACE; | |
290 | new = NULL; | |
291 | } else { | |
292 | new = kzalloc(n * sizeof(struct ftrace_event_file *), | |
293 | GFP_KERNEL); | |
294 | if (!new) { | |
295 | ret = -ENOMEM; | |
3fe3d619 | 296 | goto out; |
41a7dd42 MH |
297 | } |
298 | ||
299 | /* This copy & check loop copies the NULL stopper too */ | |
300 | for (i = 0, j = 0; j < n && i < n + 1; i++) | |
301 | if (old[i] != file) | |
302 | new[j++] = old[i]; | |
303 | } | |
304 | ||
305 | rcu_assign_pointer(tp->files, new); | |
306 | ||
307 | /* Make sure the probe is done with old files */ | |
308 | synchronize_sched(); | |
309 | kfree(old); | |
310 | } else | |
311 | tp->flags &= ~TP_FLAG_PROFILE; | |
312 | ||
61424318 | 313 | if (!trace_probe_is_enabled(tp) && trace_probe_is_registered(tp)) { |
1538f888 MH |
314 | if (trace_probe_is_return(tp)) |
315 | disable_kretprobe(&tp->rp); | |
316 | else | |
317 | disable_kprobe(&tp->rp.kp); | |
318 | } | |
3fe3d619 | 319 | out: |
41a7dd42 | 320 | return ret; |
1538f888 MH |
321 | } |
322 | ||
61424318 MH |
323 | /* Internal register function - just handle k*probes and flags */ |
324 | static int __register_trace_probe(struct trace_probe *tp) | |
413d37d1 | 325 | { |
7f6878a3 | 326 | int i, ret; |
61424318 MH |
327 | |
328 | if (trace_probe_is_registered(tp)) | |
329 | return -EINVAL; | |
330 | ||
7f6878a3 | 331 | for (i = 0; i < tp->nr_args; i++) |
8ab83f56 | 332 | traceprobe_update_arg(&tp->args[i]); |
7f6878a3 | 333 | |
61424318 MH |
334 | /* Set/clear disabled flag according to tp->flag */ |
335 | if (trace_probe_is_enabled(tp)) | |
336 | tp->rp.kp.flags &= ~KPROBE_FLAG_DISABLED; | |
337 | else | |
338 | tp->rp.kp.flags |= KPROBE_FLAG_DISABLED; | |
339 | ||
7143f168 | 340 | if (trace_probe_is_return(tp)) |
61424318 | 341 | ret = register_kretprobe(&tp->rp); |
413d37d1 | 342 | else |
61424318 MH |
343 | ret = register_kprobe(&tp->rp.kp); |
344 | ||
345 | if (ret == 0) | |
346 | tp->flags |= TP_FLAG_REGISTERED; | |
347 | else { | |
348 | pr_warning("Could not insert probe at %s+%lu: %d\n", | |
349 | trace_probe_symbol(tp), trace_probe_offset(tp), ret); | |
350 | if (ret == -ENOENT && trace_probe_is_on_module(tp)) { | |
351 | pr_warning("This probe might be able to register after" | |
352 | "target module is loaded. Continue.\n"); | |
353 | ret = 0; | |
354 | } else if (ret == -EILSEQ) { | |
355 | pr_warning("Probing address(0x%p) is not an " | |
356 | "instruction boundary.\n", | |
357 | tp->rp.kp.addr); | |
358 | ret = -EINVAL; | |
359 | } | |
360 | } | |
361 | ||
362 | return ret; | |
363 | } | |
364 | ||
365 | /* Internal unregister function - just handle k*probes and flags */ | |
366 | static void __unregister_trace_probe(struct trace_probe *tp) | |
367 | { | |
368 | if (trace_probe_is_registered(tp)) { | |
369 | if (trace_probe_is_return(tp)) | |
370 | unregister_kretprobe(&tp->rp); | |
371 | else | |
372 | unregister_kprobe(&tp->rp.kp); | |
373 | tp->flags &= ~TP_FLAG_REGISTERED; | |
374 | /* Cleanup kprobe for reuse */ | |
375 | if (tp->rp.kp.symbol_name) | |
376 | tp->rp.kp.addr = NULL; | |
377 | } | |
378 | } | |
379 | ||
380 | /* Unregister a trace_probe and probe_event: call with locking probe_lock */ | |
02ca1521 | 381 | static int unregister_trace_probe(struct trace_probe *tp) |
61424318 | 382 | { |
02ca1521 MH |
383 | /* Enabled event can not be unregistered */ |
384 | if (trace_probe_is_enabled(tp)) | |
385 | return -EBUSY; | |
386 | ||
61424318 | 387 | __unregister_trace_probe(tp); |
413d37d1 | 388 | list_del(&tp->list); |
2d5e067e | 389 | unregister_probe_event(tp); |
02ca1521 MH |
390 | |
391 | return 0; | |
413d37d1 MH |
392 | } |
393 | ||
394 | /* Register a trace_probe and probe_event */ | |
395 | static int register_trace_probe(struct trace_probe *tp) | |
396 | { | |
397 | struct trace_probe *old_tp; | |
398 | int ret; | |
399 | ||
400 | mutex_lock(&probe_lock); | |
401 | ||
61424318 | 402 | /* Delete old (same name) event if exist */ |
7143f168 | 403 | old_tp = find_trace_probe(tp->call.name, tp->call.class->system); |
2d5e067e | 404 | if (old_tp) { |
02ca1521 MH |
405 | ret = unregister_trace_probe(old_tp); |
406 | if (ret < 0) | |
407 | goto end; | |
2d5e067e MH |
408 | free_trace_probe(old_tp); |
409 | } | |
61424318 MH |
410 | |
411 | /* Register new event */ | |
2d5e067e MH |
412 | ret = register_probe_event(tp); |
413 | if (ret) { | |
426d3107 | 414 | pr_warning("Failed to register probe event(%d)\n", ret); |
2d5e067e MH |
415 | goto end; |
416 | } | |
417 | ||
61424318 MH |
418 | /* Register k*probe */ |
419 | ret = __register_trace_probe(tp); | |
420 | if (ret < 0) | |
2d5e067e | 421 | unregister_probe_event(tp); |
61424318 | 422 | else |
2d5e067e | 423 | list_add_tail(&tp->list, &probe_list); |
61424318 | 424 | |
413d37d1 MH |
425 | end: |
426 | mutex_unlock(&probe_lock); | |
427 | return ret; | |
428 | } | |
429 | ||
61424318 MH |
430 | /* Module notifier call back, checking event on the module */ |
431 | static int trace_probe_module_callback(struct notifier_block *nb, | |
432 | unsigned long val, void *data) | |
433 | { | |
434 | struct module *mod = data; | |
435 | struct trace_probe *tp; | |
436 | int ret; | |
437 | ||
438 | if (val != MODULE_STATE_COMING) | |
439 | return NOTIFY_DONE; | |
440 | ||
441 | /* Update probes on coming module */ | |
442 | mutex_lock(&probe_lock); | |
443 | list_for_each_entry(tp, &probe_list, list) { | |
444 | if (trace_probe_within_module(tp, mod)) { | |
02ca1521 | 445 | /* Don't need to check busy - this should have gone. */ |
61424318 MH |
446 | __unregister_trace_probe(tp); |
447 | ret = __register_trace_probe(tp); | |
448 | if (ret) | |
449 | pr_warning("Failed to re-register probe %s on" | |
450 | "%s: %d\n", | |
451 | tp->call.name, mod->name, ret); | |
452 | } | |
453 | } | |
454 | mutex_unlock(&probe_lock); | |
455 | ||
456 | return NOTIFY_DONE; | |
457 | } | |
458 | ||
459 | static struct notifier_block trace_probe_module_nb = { | |
460 | .notifier_call = trace_probe_module_callback, | |
461 | .priority = 1 /* Invoked after kprobe module callback */ | |
462 | }; | |
463 | ||
413d37d1 MH |
464 | static int create_trace_probe(int argc, char **argv) |
465 | { | |
466 | /* | |
467 | * Argument syntax: | |
61424318 MH |
468 | * - Add kprobe: p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS] |
469 | * - Add kretprobe: r[:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS] | |
413d37d1 | 470 | * Fetch args: |
2e06ff63 MH |
471 | * $retval : fetch return value |
472 | * $stack : fetch stack address | |
473 | * $stackN : fetch Nth of stack (N:0-) | |
413d37d1 MH |
474 | * @ADDR : fetch memory at ADDR (ADDR should be in kernel) |
475 | * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol) | |
476 | * %REG : fetch register REG | |
93ccae7a | 477 | * Dereferencing memory fetch: |
413d37d1 | 478 | * +|-offs(ARG) : fetch memory at ARG +|- offs address. |
eca0d916 MH |
479 | * Alias name of args: |
480 | * NAME=FETCHARG : set NAME as alias of FETCHARG. | |
93ccae7a MH |
481 | * Type of args: |
482 | * FETCHARG:TYPE : use TYPE instead of unsigned long. | |
413d37d1 MH |
483 | */ |
484 | struct trace_probe *tp; | |
413d37d1 | 485 | int i, ret = 0; |
3a6b7666 | 486 | bool is_return = false, is_delete = false; |
93ccae7a | 487 | char *symbol = NULL, *event = NULL, *group = NULL; |
da34634f | 488 | char *arg; |
2fba0c88 | 489 | unsigned long offset = 0; |
413d37d1 | 490 | void *addr = NULL; |
4a846b44 | 491 | char buf[MAX_EVENT_NAME_LEN]; |
413d37d1 | 492 | |
a7c312be | 493 | /* argc must be >= 1 */ |
413d37d1 | 494 | if (argv[0][0] == 'p') |
3a6b7666 | 495 | is_return = false; |
413d37d1 | 496 | else if (argv[0][0] == 'r') |
3a6b7666 | 497 | is_return = true; |
a7c312be | 498 | else if (argv[0][0] == '-') |
3a6b7666 | 499 | is_delete = true; |
e63cc239 | 500 | else { |
a7c312be MH |
501 | pr_info("Probe definition must be started with 'p', 'r' or" |
502 | " '-'.\n"); | |
413d37d1 | 503 | return -EINVAL; |
e63cc239 | 504 | } |
413d37d1 MH |
505 | |
506 | if (argv[0][1] == ':') { | |
507 | event = &argv[0][2]; | |
f52487e9 MH |
508 | if (strchr(event, '/')) { |
509 | group = event; | |
510 | event = strchr(group, '/') + 1; | |
511 | event[-1] = '\0'; | |
512 | if (strlen(group) == 0) { | |
a5efd925 | 513 | pr_info("Group name is not specified\n"); |
f52487e9 MH |
514 | return -EINVAL; |
515 | } | |
516 | } | |
413d37d1 | 517 | if (strlen(event) == 0) { |
a5efd925 | 518 | pr_info("Event name is not specified\n"); |
413d37d1 MH |
519 | return -EINVAL; |
520 | } | |
521 | } | |
a7c312be MH |
522 | if (!group) |
523 | group = KPROBE_EVENT_SYSTEM; | |
413d37d1 | 524 | |
a7c312be MH |
525 | if (is_delete) { |
526 | if (!event) { | |
527 | pr_info("Delete command needs an event name.\n"); | |
528 | return -EINVAL; | |
529 | } | |
9da79ab8 | 530 | mutex_lock(&probe_lock); |
7143f168 | 531 | tp = find_trace_probe(event, group); |
a7c312be | 532 | if (!tp) { |
9da79ab8 | 533 | mutex_unlock(&probe_lock); |
a7c312be MH |
534 | pr_info("Event %s/%s doesn't exist.\n", group, event); |
535 | return -ENOENT; | |
536 | } | |
537 | /* delete an event */ | |
02ca1521 MH |
538 | ret = unregister_trace_probe(tp); |
539 | if (ret == 0) | |
540 | free_trace_probe(tp); | |
9da79ab8 | 541 | mutex_unlock(&probe_lock); |
02ca1521 | 542 | return ret; |
a7c312be MH |
543 | } |
544 | ||
545 | if (argc < 2) { | |
546 | pr_info("Probe point is not specified.\n"); | |
547 | return -EINVAL; | |
548 | } | |
413d37d1 | 549 | if (isdigit(argv[1][0])) { |
e63cc239 MH |
550 | if (is_return) { |
551 | pr_info("Return probe point must be a symbol.\n"); | |
413d37d1 | 552 | return -EINVAL; |
e63cc239 | 553 | } |
413d37d1 | 554 | /* an address specified */ |
bcd83ea6 | 555 | ret = kstrtoul(&argv[1][0], 0, (unsigned long *)&addr); |
e63cc239 MH |
556 | if (ret) { |
557 | pr_info("Failed to parse address.\n"); | |
413d37d1 | 558 | return ret; |
e63cc239 | 559 | } |
413d37d1 MH |
560 | } else { |
561 | /* a symbol specified */ | |
562 | symbol = argv[1]; | |
563 | /* TODO: support .init module functions */ | |
8ab83f56 | 564 | ret = traceprobe_split_symbol_offset(symbol, &offset); |
e63cc239 MH |
565 | if (ret) { |
566 | pr_info("Failed to parse symbol.\n"); | |
413d37d1 | 567 | return ret; |
e63cc239 MH |
568 | } |
569 | if (offset && is_return) { | |
570 | pr_info("Return probe must be used without offset.\n"); | |
413d37d1 | 571 | return -EINVAL; |
e63cc239 | 572 | } |
413d37d1 | 573 | } |
a82378d8 | 574 | argc -= 2; argv += 2; |
413d37d1 MH |
575 | |
576 | /* setup a probe */ | |
4263565d MH |
577 | if (!event) { |
578 | /* Make a new event name */ | |
4263565d | 579 | if (symbol) |
6f3cf440 | 580 | snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld", |
4263565d MH |
581 | is_return ? 'r' : 'p', symbol, offset); |
582 | else | |
6f3cf440 | 583 | snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p", |
4263565d | 584 | is_return ? 'r' : 'p', addr); |
4a846b44 MH |
585 | event = buf; |
586 | } | |
f52487e9 MH |
587 | tp = alloc_trace_probe(group, event, addr, symbol, offset, argc, |
588 | is_return); | |
e63cc239 MH |
589 | if (IS_ERR(tp)) { |
590 | pr_info("Failed to allocate trace_probe.(%d)\n", | |
591 | (int)PTR_ERR(tp)); | |
413d37d1 | 592 | return PTR_ERR(tp); |
e63cc239 | 593 | } |
413d37d1 | 594 | |
413d37d1 | 595 | /* parse arguments */ |
a82378d8 MH |
596 | ret = 0; |
597 | for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { | |
61a52736 MH |
598 | /* Increment count for freeing args in error case */ |
599 | tp->nr_args++; | |
600 | ||
eca0d916 MH |
601 | /* Parse argument name */ |
602 | arg = strchr(argv[i], '='); | |
aba91595 | 603 | if (arg) { |
eca0d916 | 604 | *arg++ = '\0'; |
aba91595 MH |
605 | tp->args[i].name = kstrdup(argv[i], GFP_KERNEL); |
606 | } else { | |
eca0d916 | 607 | arg = argv[i]; |
aba91595 MH |
608 | /* If argument name is omitted, set "argN" */ |
609 | snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1); | |
610 | tp->args[i].name = kstrdup(buf, GFP_KERNEL); | |
611 | } | |
a703d946 | 612 | |
ba8665d7 | 613 | if (!tp->args[i].name) { |
aba91595 | 614 | pr_info("Failed to allocate argument[%d] name.\n", i); |
ba8665d7 | 615 | ret = -ENOMEM; |
413d37d1 MH |
616 | goto error; |
617 | } | |
da34634f MH |
618 | |
619 | if (!is_good_name(tp->args[i].name)) { | |
620 | pr_info("Invalid argument[%d] name: %s\n", | |
621 | i, tp->args[i].name); | |
622 | ret = -EINVAL; | |
623 | goto error; | |
624 | } | |
93ccae7a | 625 | |
8ab83f56 SD |
626 | if (traceprobe_conflict_field_name(tp->args[i].name, |
627 | tp->args, i)) { | |
aba91595 | 628 | pr_info("Argument[%d] name '%s' conflicts with " |
93ccae7a MH |
629 | "another field.\n", i, argv[i]); |
630 | ret = -EINVAL; | |
631 | goto error; | |
632 | } | |
ba8665d7 MH |
633 | |
634 | /* Parse fetch argument */ | |
8ab83f56 | 635 | ret = traceprobe_parse_probe_arg(arg, &tp->size, &tp->args[i], |
f3f096cf | 636 | is_return, true); |
e63cc239 | 637 | if (ret) { |
aba91595 | 638 | pr_info("Parse error at argument[%d]. (%d)\n", i, ret); |
413d37d1 | 639 | goto error; |
e63cc239 | 640 | } |
413d37d1 | 641 | } |
413d37d1 MH |
642 | |
643 | ret = register_trace_probe(tp); | |
644 | if (ret) | |
645 | goto error; | |
646 | return 0; | |
647 | ||
648 | error: | |
649 | free_trace_probe(tp); | |
650 | return ret; | |
651 | } | |
652 | ||
02ca1521 | 653 | static int release_all_trace_probes(void) |
413d37d1 MH |
654 | { |
655 | struct trace_probe *tp; | |
02ca1521 | 656 | int ret = 0; |
413d37d1 MH |
657 | |
658 | mutex_lock(&probe_lock); | |
02ca1521 MH |
659 | /* Ensure no probe is in use. */ |
660 | list_for_each_entry(tp, &probe_list, list) | |
661 | if (trace_probe_is_enabled(tp)) { | |
662 | ret = -EBUSY; | |
663 | goto end; | |
664 | } | |
413d37d1 MH |
665 | /* TODO: Use batch unregistration */ |
666 | while (!list_empty(&probe_list)) { | |
667 | tp = list_entry(probe_list.next, struct trace_probe, list); | |
668 | unregister_trace_probe(tp); | |
669 | free_trace_probe(tp); | |
670 | } | |
02ca1521 MH |
671 | |
672 | end: | |
413d37d1 | 673 | mutex_unlock(&probe_lock); |
02ca1521 MH |
674 | |
675 | return ret; | |
413d37d1 MH |
676 | } |
677 | ||
413d37d1 MH |
678 | /* Probes listing interfaces */ |
679 | static void *probes_seq_start(struct seq_file *m, loff_t *pos) | |
680 | { | |
681 | mutex_lock(&probe_lock); | |
682 | return seq_list_start(&probe_list, *pos); | |
683 | } | |
684 | ||
685 | static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos) | |
686 | { | |
687 | return seq_list_next(v, &probe_list, pos); | |
688 | } | |
689 | ||
690 | static void probes_seq_stop(struct seq_file *m, void *v) | |
691 | { | |
692 | mutex_unlock(&probe_lock); | |
693 | } | |
694 | ||
695 | static int probes_seq_show(struct seq_file *m, void *v) | |
696 | { | |
697 | struct trace_probe *tp = v; | |
93ccae7a | 698 | int i; |
413d37d1 | 699 | |
7143f168 | 700 | seq_printf(m, "%c", trace_probe_is_return(tp) ? 'r' : 'p'); |
8f082018 | 701 | seq_printf(m, ":%s/%s", tp->call.class->system, tp->call.name); |
413d37d1 | 702 | |
52a11f35 LJ |
703 | if (!tp->symbol) |
704 | seq_printf(m, " 0x%p", tp->rp.kp.addr); | |
705 | else if (tp->rp.kp.offset) | |
7143f168 MH |
706 | seq_printf(m, " %s+%u", trace_probe_symbol(tp), |
707 | tp->rp.kp.offset); | |
413d37d1 | 708 | else |
7143f168 | 709 | seq_printf(m, " %s", trace_probe_symbol(tp)); |
413d37d1 | 710 | |
93ccae7a MH |
711 | for (i = 0; i < tp->nr_args; i++) |
712 | seq_printf(m, " %s=%s", tp->args[i].name, tp->args[i].comm); | |
413d37d1 | 713 | seq_printf(m, "\n"); |
93ccae7a | 714 | |
413d37d1 MH |
715 | return 0; |
716 | } | |
717 | ||
718 | static const struct seq_operations probes_seq_op = { | |
719 | .start = probes_seq_start, | |
720 | .next = probes_seq_next, | |
721 | .stop = probes_seq_stop, | |
722 | .show = probes_seq_show | |
723 | }; | |
724 | ||
725 | static int probes_open(struct inode *inode, struct file *file) | |
726 | { | |
02ca1521 MH |
727 | int ret; |
728 | ||
729 | if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { | |
730 | ret = release_all_trace_probes(); | |
731 | if (ret < 0) | |
732 | return ret; | |
733 | } | |
413d37d1 MH |
734 | |
735 | return seq_open(file, &probes_seq_op); | |
736 | } | |
737 | ||
413d37d1 MH |
738 | static ssize_t probes_write(struct file *file, const char __user *buffer, |
739 | size_t count, loff_t *ppos) | |
740 | { | |
8ab83f56 SD |
741 | return traceprobe_probes_write(file, buffer, count, ppos, |
742 | create_trace_probe); | |
413d37d1 MH |
743 | } |
744 | ||
745 | static const struct file_operations kprobe_events_ops = { | |
746 | .owner = THIS_MODULE, | |
747 | .open = probes_open, | |
748 | .read = seq_read, | |
749 | .llseek = seq_lseek, | |
750 | .release = seq_release, | |
751 | .write = probes_write, | |
752 | }; | |
753 | ||
cd7e7bd5 MH |
754 | /* Probes profiling interfaces */ |
755 | static int probes_profile_seq_show(struct seq_file *m, void *v) | |
756 | { | |
757 | struct trace_probe *tp = v; | |
758 | ||
759 | seq_printf(m, " %-44s %15lu %15lu\n", tp->call.name, tp->nhit, | |
4a846b44 | 760 | tp->rp.kp.nmissed); |
cd7e7bd5 MH |
761 | |
762 | return 0; | |
763 | } | |
764 | ||
765 | static const struct seq_operations profile_seq_op = { | |
766 | .start = probes_seq_start, | |
767 | .next = probes_seq_next, | |
768 | .stop = probes_seq_stop, | |
769 | .show = probes_profile_seq_show | |
770 | }; | |
771 | ||
772 | static int profile_open(struct inode *inode, struct file *file) | |
773 | { | |
774 | return seq_open(file, &profile_seq_op); | |
775 | } | |
776 | ||
777 | static const struct file_operations kprobe_profile_ops = { | |
778 | .owner = THIS_MODULE, | |
779 | .open = profile_open, | |
780 | .read = seq_read, | |
781 | .llseek = seq_lseek, | |
782 | .release = seq_release, | |
783 | }; | |
784 | ||
e09c8614 MH |
785 | /* Sum up total data length for dynamic arraies (strings) */ |
786 | static __kprobes int __get_data_size(struct trace_probe *tp, | |
787 | struct pt_regs *regs) | |
788 | { | |
789 | int i, ret = 0; | |
790 | u32 len; | |
791 | ||
792 | for (i = 0; i < tp->nr_args; i++) | |
793 | if (unlikely(tp->args[i].fetch_size.fn)) { | |
794 | call_fetch(&tp->args[i].fetch_size, regs, &len); | |
795 | ret += len; | |
796 | } | |
797 | ||
798 | return ret; | |
799 | } | |
800 | ||
801 | /* Store the value of each argument */ | |
802 | static __kprobes void store_trace_args(int ent_size, struct trace_probe *tp, | |
803 | struct pt_regs *regs, | |
804 | u8 *data, int maxlen) | |
805 | { | |
806 | int i; | |
807 | u32 end = tp->size; | |
808 | u32 *dl; /* Data (relative) location */ | |
809 | ||
810 | for (i = 0; i < tp->nr_args; i++) { | |
811 | if (unlikely(tp->args[i].fetch_size.fn)) { | |
812 | /* | |
813 | * First, we set the relative location and | |
814 | * maximum data length to *dl | |
815 | */ | |
816 | dl = (u32 *)(data + tp->args[i].offset); | |
817 | *dl = make_data_rloc(maxlen, end - tp->args[i].offset); | |
818 | /* Then try to fetch string or dynamic array data */ | |
819 | call_fetch(&tp->args[i].fetch, regs, dl); | |
820 | /* Reduce maximum length */ | |
821 | end += get_rloc_len(*dl); | |
822 | maxlen -= get_rloc_len(*dl); | |
823 | /* Trick here, convert data_rloc to data_loc */ | |
824 | *dl = convert_rloc_to_loc(*dl, | |
825 | ent_size + tp->args[i].offset); | |
826 | } else | |
827 | /* Just fetching data normally */ | |
828 | call_fetch(&tp->args[i].fetch, regs, | |
829 | data + tp->args[i].offset); | |
830 | } | |
831 | } | |
832 | ||
413d37d1 | 833 | /* Kprobe handler */ |
2b106aab | 834 | static __kprobes void |
41a7dd42 MH |
835 | __kprobe_trace_func(struct trace_probe *tp, struct pt_regs *regs, |
836 | struct ftrace_event_file *ftrace_file) | |
413d37d1 | 837 | { |
93ccae7a | 838 | struct kprobe_trace_entry_head *entry; |
413d37d1 | 839 | struct ring_buffer_event *event; |
8f8ffe24 | 840 | struct ring_buffer *buffer; |
e09c8614 | 841 | int size, dsize, pc; |
413d37d1 | 842 | unsigned long irq_flags; |
4263565d | 843 | struct ftrace_event_call *call = &tp->call; |
413d37d1 | 844 | |
41a7dd42 MH |
845 | WARN_ON(call != ftrace_file->event_call); |
846 | ||
b8820084 MH |
847 | if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags)) |
848 | return; | |
849 | ||
413d37d1 MH |
850 | local_save_flags(irq_flags); |
851 | pc = preempt_count(); | |
852 | ||
e09c8614 MH |
853 | dsize = __get_data_size(tp, regs); |
854 | size = sizeof(*entry) + tp->size + dsize; | |
413d37d1 | 855 | |
41a7dd42 MH |
856 | event = trace_event_buffer_lock_reserve(&buffer, ftrace_file, |
857 | call->event.type, | |
858 | size, irq_flags, pc); | |
413d37d1 | 859 | if (!event) |
1e12a4a7 | 860 | return; |
413d37d1 MH |
861 | |
862 | entry = ring_buffer_event_data(event); | |
2b106aab | 863 | entry->ip = (unsigned long)tp->rp.kp.addr; |
e09c8614 | 864 | store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize); |
413d37d1 | 865 | |
8f8ffe24 | 866 | if (!filter_current_check_discard(buffer, call, entry, event)) |
0d5c6e1c SR |
867 | trace_buffer_unlock_commit_regs(buffer, event, |
868 | irq_flags, pc, regs); | |
413d37d1 MH |
869 | } |
870 | ||
41a7dd42 MH |
871 | static __kprobes void |
872 | kprobe_trace_func(struct trace_probe *tp, struct pt_regs *regs) | |
873 | { | |
c02c7e65 MH |
874 | /* |
875 | * Note: preempt is already disabled around the kprobe handler. | |
876 | * However, we still need an smp_read_barrier_depends() corresponding | |
877 | * to smp_wmb() in rcu_assign_pointer() to access the pointer. | |
878 | */ | |
879 | struct ftrace_event_file **file = rcu_dereference_raw(tp->files); | |
880 | ||
881 | if (unlikely(!file)) | |
882 | return; | |
41a7dd42 | 883 | |
41a7dd42 MH |
884 | while (*file) { |
885 | __kprobe_trace_func(tp, regs, *file); | |
886 | file++; | |
887 | } | |
888 | } | |
889 | ||
413d37d1 | 890 | /* Kretprobe handler */ |
2b106aab | 891 | static __kprobes void |
41a7dd42 MH |
892 | __kretprobe_trace_func(struct trace_probe *tp, struct kretprobe_instance *ri, |
893 | struct pt_regs *regs, | |
894 | struct ftrace_event_file *ftrace_file) | |
413d37d1 | 895 | { |
93ccae7a | 896 | struct kretprobe_trace_entry_head *entry; |
413d37d1 | 897 | struct ring_buffer_event *event; |
8f8ffe24 | 898 | struct ring_buffer *buffer; |
e09c8614 | 899 | int size, pc, dsize; |
413d37d1 | 900 | unsigned long irq_flags; |
4263565d | 901 | struct ftrace_event_call *call = &tp->call; |
413d37d1 | 902 | |
41a7dd42 MH |
903 | WARN_ON(call != ftrace_file->event_call); |
904 | ||
b8820084 MH |
905 | if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags)) |
906 | return; | |
907 | ||
413d37d1 MH |
908 | local_save_flags(irq_flags); |
909 | pc = preempt_count(); | |
910 | ||
e09c8614 MH |
911 | dsize = __get_data_size(tp, regs); |
912 | size = sizeof(*entry) + tp->size + dsize; | |
413d37d1 | 913 | |
41a7dd42 MH |
914 | event = trace_event_buffer_lock_reserve(&buffer, ftrace_file, |
915 | call->event.type, | |
916 | size, irq_flags, pc); | |
413d37d1 | 917 | if (!event) |
1e12a4a7 | 918 | return; |
413d37d1 MH |
919 | |
920 | entry = ring_buffer_event_data(event); | |
4a846b44 | 921 | entry->func = (unsigned long)tp->rp.kp.addr; |
413d37d1 | 922 | entry->ret_ip = (unsigned long)ri->ret_addr; |
e09c8614 | 923 | store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize); |
413d37d1 | 924 | |
8f8ffe24 | 925 | if (!filter_current_check_discard(buffer, call, entry, event)) |
0d5c6e1c SR |
926 | trace_buffer_unlock_commit_regs(buffer, event, |
927 | irq_flags, pc, regs); | |
413d37d1 MH |
928 | } |
929 | ||
41a7dd42 MH |
930 | static __kprobes void |
931 | kretprobe_trace_func(struct trace_probe *tp, struct kretprobe_instance *ri, | |
932 | struct pt_regs *regs) | |
933 | { | |
c02c7e65 MH |
934 | /* |
935 | * Note: preempt is already disabled around the kprobe handler. | |
936 | * However, we still need an smp_read_barrier_depends() corresponding | |
937 | * to smp_wmb() in rcu_assign_pointer() to access the pointer. | |
938 | */ | |
939 | struct ftrace_event_file **file = rcu_dereference_raw(tp->files); | |
940 | ||
941 | if (unlikely(!file)) | |
942 | return; | |
41a7dd42 | 943 | |
41a7dd42 MH |
944 | while (*file) { |
945 | __kretprobe_trace_func(tp, ri, regs, *file); | |
946 | file++; | |
947 | } | |
948 | } | |
949 | ||
413d37d1 | 950 | /* Event entry printers */ |
b62fdd97 | 951 | static enum print_line_t |
a9a57763 SR |
952 | print_kprobe_event(struct trace_iterator *iter, int flags, |
953 | struct trace_event *event) | |
413d37d1 | 954 | { |
93ccae7a | 955 | struct kprobe_trace_entry_head *field; |
413d37d1 | 956 | struct trace_seq *s = &iter->seq; |
eca0d916 | 957 | struct trace_probe *tp; |
93ccae7a | 958 | u8 *data; |
413d37d1 MH |
959 | int i; |
960 | ||
93ccae7a | 961 | field = (struct kprobe_trace_entry_head *)iter->ent; |
80decc70 | 962 | tp = container_of(event, struct trace_probe, call.event); |
413d37d1 | 963 | |
6e9f23d1 MH |
964 | if (!trace_seq_printf(s, "%s: (", tp->call.name)) |
965 | goto partial; | |
966 | ||
413d37d1 MH |
967 | if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET)) |
968 | goto partial; | |
969 | ||
6e9f23d1 | 970 | if (!trace_seq_puts(s, ")")) |
413d37d1 MH |
971 | goto partial; |
972 | ||
93ccae7a MH |
973 | data = (u8 *)&field[1]; |
974 | for (i = 0; i < tp->nr_args; i++) | |
975 | if (!tp->args[i].type->print(s, tp->args[i].name, | |
e09c8614 | 976 | data + tp->args[i].offset, field)) |
413d37d1 MH |
977 | goto partial; |
978 | ||
979 | if (!trace_seq_puts(s, "\n")) | |
980 | goto partial; | |
981 | ||
982 | return TRACE_TYPE_HANDLED; | |
983 | partial: | |
984 | return TRACE_TYPE_PARTIAL_LINE; | |
985 | } | |
986 | ||
b62fdd97 | 987 | static enum print_line_t |
a9a57763 SR |
988 | print_kretprobe_event(struct trace_iterator *iter, int flags, |
989 | struct trace_event *event) | |
413d37d1 | 990 | { |
93ccae7a | 991 | struct kretprobe_trace_entry_head *field; |
413d37d1 | 992 | struct trace_seq *s = &iter->seq; |
eca0d916 | 993 | struct trace_probe *tp; |
93ccae7a | 994 | u8 *data; |
413d37d1 MH |
995 | int i; |
996 | ||
93ccae7a | 997 | field = (struct kretprobe_trace_entry_head *)iter->ent; |
80decc70 | 998 | tp = container_of(event, struct trace_probe, call.event); |
413d37d1 | 999 | |
6e9f23d1 MH |
1000 | if (!trace_seq_printf(s, "%s: (", tp->call.name)) |
1001 | goto partial; | |
1002 | ||
413d37d1 MH |
1003 | if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET)) |
1004 | goto partial; | |
1005 | ||
1006 | if (!trace_seq_puts(s, " <- ")) | |
1007 | goto partial; | |
1008 | ||
1009 | if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET)) | |
1010 | goto partial; | |
1011 | ||
6e9f23d1 | 1012 | if (!trace_seq_puts(s, ")")) |
413d37d1 MH |
1013 | goto partial; |
1014 | ||
93ccae7a MH |
1015 | data = (u8 *)&field[1]; |
1016 | for (i = 0; i < tp->nr_args; i++) | |
1017 | if (!tp->args[i].type->print(s, tp->args[i].name, | |
e09c8614 | 1018 | data + tp->args[i].offset, field)) |
413d37d1 MH |
1019 | goto partial; |
1020 | ||
1021 | if (!trace_seq_puts(s, "\n")) | |
1022 | goto partial; | |
1023 | ||
1024 | return TRACE_TYPE_HANDLED; | |
1025 | partial: | |
1026 | return TRACE_TYPE_PARTIAL_LINE; | |
1027 | } | |
1028 | ||
413d37d1 MH |
1029 | |
1030 | static int kprobe_event_define_fields(struct ftrace_event_call *event_call) | |
1031 | { | |
1032 | int ret, i; | |
93ccae7a | 1033 | struct kprobe_trace_entry_head field; |
413d37d1 MH |
1034 | struct trace_probe *tp = (struct trace_probe *)event_call->data; |
1035 | ||
a703d946 | 1036 | DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0); |
eca0d916 | 1037 | /* Set argument names as fields */ |
93ccae7a | 1038 | for (i = 0; i < tp->nr_args; i++) { |
e09c8614 | 1039 | ret = trace_define_field(event_call, tp->args[i].type->fmttype, |
93ccae7a MH |
1040 | tp->args[i].name, |
1041 | sizeof(field) + tp->args[i].offset, | |
1042 | tp->args[i].type->size, | |
1043 | tp->args[i].type->is_signed, | |
1044 | FILTER_OTHER); | |
1045 | if (ret) | |
1046 | return ret; | |
1047 | } | |
413d37d1 MH |
1048 | return 0; |
1049 | } | |
1050 | ||
1051 | static int kretprobe_event_define_fields(struct ftrace_event_call *event_call) | |
1052 | { | |
1053 | int ret, i; | |
93ccae7a | 1054 | struct kretprobe_trace_entry_head field; |
413d37d1 MH |
1055 | struct trace_probe *tp = (struct trace_probe *)event_call->data; |
1056 | ||
a703d946 MH |
1057 | DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0); |
1058 | DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0); | |
eca0d916 | 1059 | /* Set argument names as fields */ |
93ccae7a | 1060 | for (i = 0; i < tp->nr_args; i++) { |
e09c8614 | 1061 | ret = trace_define_field(event_call, tp->args[i].type->fmttype, |
93ccae7a MH |
1062 | tp->args[i].name, |
1063 | sizeof(field) + tp->args[i].offset, | |
1064 | tp->args[i].type->size, | |
1065 | tp->args[i].type->is_signed, | |
1066 | FILTER_OTHER); | |
1067 | if (ret) | |
1068 | return ret; | |
1069 | } | |
413d37d1 MH |
1070 | return 0; |
1071 | } | |
1072 | ||
a342a028 LJ |
1073 | static int __set_print_fmt(struct trace_probe *tp, char *buf, int len) |
1074 | { | |
1075 | int i; | |
1076 | int pos = 0; | |
1077 | ||
1078 | const char *fmt, *arg; | |
1079 | ||
7143f168 | 1080 | if (!trace_probe_is_return(tp)) { |
a342a028 LJ |
1081 | fmt = "(%lx)"; |
1082 | arg = "REC->" FIELD_STRING_IP; | |
1083 | } else { | |
1084 | fmt = "(%lx <- %lx)"; | |
1085 | arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP; | |
1086 | } | |
1087 | ||
1088 | /* When len=0, we just calculate the needed length */ | |
1089 | #define LEN_OR_ZERO (len ? len - pos : 0) | |
1090 | ||
1091 | pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt); | |
1092 | ||
1093 | for (i = 0; i < tp->nr_args; i++) { | |
93ccae7a MH |
1094 | pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%s", |
1095 | tp->args[i].name, tp->args[i].type->fmt); | |
a342a028 LJ |
1096 | } |
1097 | ||
1098 | pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg); | |
1099 | ||
1100 | for (i = 0; i < tp->nr_args; i++) { | |
e09c8614 MH |
1101 | if (strcmp(tp->args[i].type->name, "string") == 0) |
1102 | pos += snprintf(buf + pos, LEN_OR_ZERO, | |
1103 | ", __get_str(%s)", | |
1104 | tp->args[i].name); | |
1105 | else | |
1106 | pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s", | |
1107 | tp->args[i].name); | |
a342a028 LJ |
1108 | } |
1109 | ||
1110 | #undef LEN_OR_ZERO | |
1111 | ||
1112 | /* return the length of print_fmt */ | |
1113 | return pos; | |
1114 | } | |
1115 | ||
1116 | static int set_print_fmt(struct trace_probe *tp) | |
1117 | { | |
1118 | int len; | |
1119 | char *print_fmt; | |
1120 | ||
1121 | /* First: called with 0 length to calculate the needed length */ | |
1122 | len = __set_print_fmt(tp, NULL, 0); | |
1123 | print_fmt = kmalloc(len + 1, GFP_KERNEL); | |
1124 | if (!print_fmt) | |
1125 | return -ENOMEM; | |
1126 | ||
1127 | /* Second: actually write the @print_fmt */ | |
1128 | __set_print_fmt(tp, print_fmt, len + 1); | |
1129 | tp->call.print_fmt = print_fmt; | |
1130 | ||
1131 | return 0; | |
1132 | } | |
1133 | ||
07b139c8 | 1134 | #ifdef CONFIG_PERF_EVENTS |
e08d1c65 MH |
1135 | |
1136 | /* Kprobe profile handler */ | |
2b106aab MH |
1137 | static __kprobes void |
1138 | kprobe_perf_func(struct trace_probe *tp, struct pt_regs *regs) | |
e08d1c65 | 1139 | { |
e08d1c65 | 1140 | struct ftrace_event_call *call = &tp->call; |
93ccae7a | 1141 | struct kprobe_trace_entry_head *entry; |
1c024eca | 1142 | struct hlist_head *head; |
e09c8614 | 1143 | int size, __size, dsize; |
4ed7c92d | 1144 | int rctx; |
e08d1c65 | 1145 | |
288e984e ON |
1146 | head = this_cpu_ptr(call->perf_events); |
1147 | if (hlist_empty(head)) | |
1148 | return; | |
1149 | ||
e09c8614 MH |
1150 | dsize = __get_data_size(tp, regs); |
1151 | __size = sizeof(*entry) + tp->size + dsize; | |
74ebb63e MH |
1152 | size = ALIGN(__size + sizeof(u32), sizeof(u64)); |
1153 | size -= sizeof(u32); | |
97d5a220 | 1154 | if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, |
a1a138d0 | 1155 | "profile buffer not large enough")) |
1e12a4a7 | 1156 | return; |
ce71b9df | 1157 | |
ff5f149b | 1158 | entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx); |
430ad5a6 | 1159 | if (!entry) |
1e12a4a7 | 1160 | return; |
a1a138d0 | 1161 | |
2b106aab | 1162 | entry->ip = (unsigned long)tp->rp.kp.addr; |
e09c8614 MH |
1163 | memset(&entry[1], 0, dsize); |
1164 | store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize); | |
e6dab5ff AV |
1165 | perf_trace_buf_submit(entry, size, rctx, |
1166 | entry->ip, 1, regs, head, NULL); | |
e08d1c65 MH |
1167 | } |
1168 | ||
1169 | /* Kretprobe profile handler */ | |
2b106aab MH |
1170 | static __kprobes void |
1171 | kretprobe_perf_func(struct trace_probe *tp, struct kretprobe_instance *ri, | |
1172 | struct pt_regs *regs) | |
e08d1c65 | 1173 | { |
e08d1c65 | 1174 | struct ftrace_event_call *call = &tp->call; |
93ccae7a | 1175 | struct kretprobe_trace_entry_head *entry; |
1c024eca | 1176 | struct hlist_head *head; |
e09c8614 | 1177 | int size, __size, dsize; |
4ed7c92d | 1178 | int rctx; |
e08d1c65 | 1179 | |
288e984e ON |
1180 | head = this_cpu_ptr(call->perf_events); |
1181 | if (hlist_empty(head)) | |
1182 | return; | |
1183 | ||
e09c8614 MH |
1184 | dsize = __get_data_size(tp, regs); |
1185 | __size = sizeof(*entry) + tp->size + dsize; | |
74ebb63e MH |
1186 | size = ALIGN(__size + sizeof(u32), sizeof(u64)); |
1187 | size -= sizeof(u32); | |
97d5a220 | 1188 | if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, |
a1a138d0 | 1189 | "profile buffer not large enough")) |
1e12a4a7 | 1190 | return; |
444a2a3b | 1191 | |
ff5f149b | 1192 | entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx); |
430ad5a6 | 1193 | if (!entry) |
1e12a4a7 | 1194 | return; |
e08d1c65 | 1195 | |
a1a138d0 MH |
1196 | entry->func = (unsigned long)tp->rp.kp.addr; |
1197 | entry->ret_ip = (unsigned long)ri->ret_addr; | |
e09c8614 | 1198 | store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize); |
e6dab5ff AV |
1199 | perf_trace_buf_submit(entry, size, rctx, |
1200 | entry->ret_ip, 1, regs, head, NULL); | |
e08d1c65 | 1201 | } |
07b139c8 | 1202 | #endif /* CONFIG_PERF_EVENTS */ |
50d78056 | 1203 | |
3fe3d619 ON |
1204 | /* |
1205 | * called by perf_trace_init() or __ftrace_set_clr_event() under event_mutex. | |
1206 | * | |
1207 | * kprobe_trace_self_tests_init() does enable_trace_probe/disable_trace_probe | |
1208 | * lockless, but we can't race with this __init function. | |
1209 | */ | |
2239291a | 1210 | static __kprobes |
ceec0b6f JO |
1211 | int kprobe_register(struct ftrace_event_call *event, |
1212 | enum trace_reg type, void *data) | |
2239291a | 1213 | { |
1538f888 | 1214 | struct trace_probe *tp = (struct trace_probe *)event->data; |
41a7dd42 | 1215 | struct ftrace_event_file *file = data; |
1538f888 | 1216 | |
2239291a SR |
1217 | switch (type) { |
1218 | case TRACE_REG_REGISTER: | |
41a7dd42 | 1219 | return enable_trace_probe(tp, file); |
2239291a | 1220 | case TRACE_REG_UNREGISTER: |
41a7dd42 | 1221 | return disable_trace_probe(tp, file); |
2239291a SR |
1222 | |
1223 | #ifdef CONFIG_PERF_EVENTS | |
1224 | case TRACE_REG_PERF_REGISTER: | |
41a7dd42 | 1225 | return enable_trace_probe(tp, NULL); |
2239291a | 1226 | case TRACE_REG_PERF_UNREGISTER: |
41a7dd42 | 1227 | return disable_trace_probe(tp, NULL); |
ceec0b6f JO |
1228 | case TRACE_REG_PERF_OPEN: |
1229 | case TRACE_REG_PERF_CLOSE: | |
489c75c3 JO |
1230 | case TRACE_REG_PERF_ADD: |
1231 | case TRACE_REG_PERF_DEL: | |
ceec0b6f | 1232 | return 0; |
2239291a SR |
1233 | #endif |
1234 | } | |
1235 | return 0; | |
1236 | } | |
50d78056 MH |
1237 | |
1238 | static __kprobes | |
1239 | int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs) | |
1240 | { | |
1241 | struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp); | |
e08d1c65 | 1242 | |
48182bd2 MH |
1243 | tp->nhit++; |
1244 | ||
50d78056 | 1245 | if (tp->flags & TP_FLAG_TRACE) |
2b106aab | 1246 | kprobe_trace_func(tp, regs); |
07b139c8 | 1247 | #ifdef CONFIG_PERF_EVENTS |
50d78056 | 1248 | if (tp->flags & TP_FLAG_PROFILE) |
2b106aab | 1249 | kprobe_perf_func(tp, regs); |
07b139c8 | 1250 | #endif |
50d78056 MH |
1251 | return 0; /* We don't tweek kernel, so just return 0 */ |
1252 | } | |
1253 | ||
1254 | static __kprobes | |
1255 | int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs) | |
1256 | { | |
1257 | struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp); | |
1258 | ||
48182bd2 MH |
1259 | tp->nhit++; |
1260 | ||
50d78056 | 1261 | if (tp->flags & TP_FLAG_TRACE) |
2b106aab | 1262 | kretprobe_trace_func(tp, ri, regs); |
07b139c8 | 1263 | #ifdef CONFIG_PERF_EVENTS |
50d78056 | 1264 | if (tp->flags & TP_FLAG_PROFILE) |
2b106aab | 1265 | kretprobe_perf_func(tp, ri, regs); |
07b139c8 | 1266 | #endif |
50d78056 MH |
1267 | return 0; /* We don't tweek kernel, so just return 0 */ |
1268 | } | |
e08d1c65 | 1269 | |
a9a57763 SR |
1270 | static struct trace_event_functions kretprobe_funcs = { |
1271 | .trace = print_kretprobe_event | |
1272 | }; | |
1273 | ||
1274 | static struct trace_event_functions kprobe_funcs = { | |
1275 | .trace = print_kprobe_event | |
1276 | }; | |
1277 | ||
413d37d1 MH |
1278 | static int register_probe_event(struct trace_probe *tp) |
1279 | { | |
1280 | struct ftrace_event_call *call = &tp->call; | |
1281 | int ret; | |
1282 | ||
1283 | /* Initialize ftrace_event_call */ | |
ffb9f995 | 1284 | INIT_LIST_HEAD(&call->class->fields); |
7143f168 | 1285 | if (trace_probe_is_return(tp)) { |
80decc70 | 1286 | call->event.funcs = &kretprobe_funcs; |
2e33af02 | 1287 | call->class->define_fields = kretprobe_event_define_fields; |
413d37d1 | 1288 | } else { |
80decc70 | 1289 | call->event.funcs = &kprobe_funcs; |
2e33af02 | 1290 | call->class->define_fields = kprobe_event_define_fields; |
413d37d1 | 1291 | } |
a342a028 LJ |
1292 | if (set_print_fmt(tp) < 0) |
1293 | return -ENOMEM; | |
32c0edae SR |
1294 | ret = register_ftrace_event(&call->event); |
1295 | if (!ret) { | |
a342a028 | 1296 | kfree(call->print_fmt); |
ff50d991 | 1297 | return -ENODEV; |
a342a028 | 1298 | } |
553552ce | 1299 | call->flags = 0; |
2239291a | 1300 | call->class->reg = kprobe_register; |
413d37d1 MH |
1301 | call->data = tp; |
1302 | ret = trace_add_event_call(call); | |
ff50d991 | 1303 | if (ret) { |
413d37d1 | 1304 | pr_info("Failed to register kprobe event: %s\n", call->name); |
a342a028 | 1305 | kfree(call->print_fmt); |
80decc70 | 1306 | unregister_ftrace_event(&call->event); |
ff50d991 | 1307 | } |
413d37d1 MH |
1308 | return ret; |
1309 | } | |
1310 | ||
1311 | static void unregister_probe_event(struct trace_probe *tp) | |
1312 | { | |
ff50d991 | 1313 | /* tp->event is unregistered in trace_remove_event_call() */ |
413d37d1 | 1314 | trace_remove_event_call(&tp->call); |
a342a028 | 1315 | kfree(tp->call.print_fmt); |
413d37d1 MH |
1316 | } |
1317 | ||
25985edc | 1318 | /* Make a debugfs interface for controlling probe points */ |
413d37d1 MH |
1319 | static __init int init_kprobe_trace(void) |
1320 | { | |
1321 | struct dentry *d_tracer; | |
1322 | struct dentry *entry; | |
413d37d1 | 1323 | |
61424318 MH |
1324 | if (register_module_notifier(&trace_probe_module_nb)) |
1325 | return -EINVAL; | |
1326 | ||
413d37d1 MH |
1327 | d_tracer = tracing_init_dentry(); |
1328 | if (!d_tracer) | |
1329 | return 0; | |
1330 | ||
1331 | entry = debugfs_create_file("kprobe_events", 0644, d_tracer, | |
1332 | NULL, &kprobe_events_ops); | |
1333 | ||
cd7e7bd5 | 1334 | /* Event list interface */ |
413d37d1 MH |
1335 | if (!entry) |
1336 | pr_warning("Could not create debugfs " | |
1337 | "'kprobe_events' entry\n"); | |
cd7e7bd5 MH |
1338 | |
1339 | /* Profile interface */ | |
1340 | entry = debugfs_create_file("kprobe_profile", 0444, d_tracer, | |
1341 | NULL, &kprobe_profile_ops); | |
1342 | ||
1343 | if (!entry) | |
1344 | pr_warning("Could not create debugfs " | |
1345 | "'kprobe_profile' entry\n"); | |
413d37d1 MH |
1346 | return 0; |
1347 | } | |
1348 | fs_initcall(init_kprobe_trace); | |
1349 | ||
1350 | ||
1351 | #ifdef CONFIG_FTRACE_STARTUP_TEST | |
1352 | ||
265a5b7e SR |
1353 | /* |
1354 | * The "__used" keeps gcc from removing the function symbol | |
1355 | * from the kallsyms table. | |
1356 | */ | |
1357 | static __used int kprobe_trace_selftest_target(int a1, int a2, int a3, | |
1358 | int a4, int a5, int a6) | |
413d37d1 MH |
1359 | { |
1360 | return a1 + a2 + a3 + a4 + a5 + a6; | |
1361 | } | |
1362 | ||
41a7dd42 MH |
1363 | static struct ftrace_event_file * |
1364 | find_trace_probe_file(struct trace_probe *tp, struct trace_array *tr) | |
1365 | { | |
1366 | struct ftrace_event_file *file; | |
1367 | ||
1368 | list_for_each_entry(file, &tr->events, list) | |
1369 | if (file->event_call == &tp->call) | |
1370 | return file; | |
1371 | ||
1372 | return NULL; | |
1373 | } | |
1374 | ||
3fe3d619 ON |
1375 | /* |
1376 | * Nobody but us can call enable_trace_probe/disable_trace_probe at this | |
1377 | * stage, we can do this lockless. | |
1378 | */ | |
413d37d1 MH |
1379 | static __init int kprobe_trace_self_tests_init(void) |
1380 | { | |
231e36f4 | 1381 | int ret, warn = 0; |
413d37d1 | 1382 | int (*target)(int, int, int, int, int, int); |
231e36f4 | 1383 | struct trace_probe *tp; |
41a7dd42 | 1384 | struct ftrace_event_file *file; |
413d37d1 MH |
1385 | |
1386 | target = kprobe_trace_selftest_target; | |
1387 | ||
1388 | pr_info("Testing kprobe tracing: "); | |
1389 | ||
8ab83f56 SD |
1390 | ret = traceprobe_command("p:testprobe kprobe_trace_selftest_target " |
1391 | "$stack $stack0 +0($stack)", | |
1392 | create_trace_probe); | |
231e36f4 | 1393 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1394 | pr_warn("error on probing function entry.\n"); |
231e36f4 MH |
1395 | warn++; |
1396 | } else { | |
1397 | /* Enable trace point */ | |
7143f168 | 1398 | tp = find_trace_probe("testprobe", KPROBE_EVENT_SYSTEM); |
231e36f4 | 1399 | if (WARN_ON_ONCE(tp == NULL)) { |
41a7dd42 | 1400 | pr_warn("error on getting new probe.\n"); |
231e36f4 | 1401 | warn++; |
41a7dd42 MH |
1402 | } else { |
1403 | file = find_trace_probe_file(tp, top_trace_array()); | |
1404 | if (WARN_ON_ONCE(file == NULL)) { | |
1405 | pr_warn("error on getting probe file.\n"); | |
1406 | warn++; | |
1407 | } else | |
1408 | enable_trace_probe(tp, file); | |
1409 | } | |
231e36f4 | 1410 | } |
413d37d1 | 1411 | |
8ab83f56 SD |
1412 | ret = traceprobe_command("r:testprobe2 kprobe_trace_selftest_target " |
1413 | "$retval", create_trace_probe); | |
231e36f4 | 1414 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1415 | pr_warn("error on probing function return.\n"); |
231e36f4 MH |
1416 | warn++; |
1417 | } else { | |
1418 | /* Enable trace point */ | |
7143f168 | 1419 | tp = find_trace_probe("testprobe2", KPROBE_EVENT_SYSTEM); |
231e36f4 | 1420 | if (WARN_ON_ONCE(tp == NULL)) { |
41a7dd42 | 1421 | pr_warn("error on getting 2nd new probe.\n"); |
231e36f4 | 1422 | warn++; |
41a7dd42 MH |
1423 | } else { |
1424 | file = find_trace_probe_file(tp, top_trace_array()); | |
1425 | if (WARN_ON_ONCE(file == NULL)) { | |
1426 | pr_warn("error on getting probe file.\n"); | |
1427 | warn++; | |
1428 | } else | |
1429 | enable_trace_probe(tp, file); | |
1430 | } | |
231e36f4 MH |
1431 | } |
1432 | ||
1433 | if (warn) | |
1434 | goto end; | |
413d37d1 MH |
1435 | |
1436 | ret = target(1, 2, 3, 4, 5, 6); | |
1437 | ||
02ca1521 MH |
1438 | /* Disable trace points before removing it */ |
1439 | tp = find_trace_probe("testprobe", KPROBE_EVENT_SYSTEM); | |
1440 | if (WARN_ON_ONCE(tp == NULL)) { | |
41a7dd42 | 1441 | pr_warn("error on getting test probe.\n"); |
02ca1521 | 1442 | warn++; |
41a7dd42 MH |
1443 | } else { |
1444 | file = find_trace_probe_file(tp, top_trace_array()); | |
1445 | if (WARN_ON_ONCE(file == NULL)) { | |
1446 | pr_warn("error on getting probe file.\n"); | |
1447 | warn++; | |
1448 | } else | |
1449 | disable_trace_probe(tp, file); | |
1450 | } | |
02ca1521 MH |
1451 | |
1452 | tp = find_trace_probe("testprobe2", KPROBE_EVENT_SYSTEM); | |
1453 | if (WARN_ON_ONCE(tp == NULL)) { | |
41a7dd42 | 1454 | pr_warn("error on getting 2nd test probe.\n"); |
02ca1521 | 1455 | warn++; |
41a7dd42 MH |
1456 | } else { |
1457 | file = find_trace_probe_file(tp, top_trace_array()); | |
1458 | if (WARN_ON_ONCE(file == NULL)) { | |
1459 | pr_warn("error on getting probe file.\n"); | |
1460 | warn++; | |
1461 | } else | |
1462 | disable_trace_probe(tp, file); | |
1463 | } | |
02ca1521 | 1464 | |
8ab83f56 | 1465 | ret = traceprobe_command("-:testprobe", create_trace_probe); |
231e36f4 | 1466 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1467 | pr_warn("error on deleting a probe.\n"); |
231e36f4 MH |
1468 | warn++; |
1469 | } | |
1470 | ||
8ab83f56 | 1471 | ret = traceprobe_command("-:testprobe2", create_trace_probe); |
231e36f4 | 1472 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1473 | pr_warn("error on deleting a probe.\n"); |
231e36f4 MH |
1474 | warn++; |
1475 | } | |
413d37d1 | 1476 | |
231e36f4 | 1477 | end: |
7143f168 | 1478 | release_all_trace_probes(); |
231e36f4 MH |
1479 | if (warn) |
1480 | pr_cont("NG: Some tests are failed. Please check them.\n"); | |
1481 | else | |
1482 | pr_cont("OK\n"); | |
413d37d1 MH |
1483 | return 0; |
1484 | } | |
1485 | ||
1486 | late_initcall(kprobe_trace_self_tests_init); | |
1487 | ||
1488 | #endif |