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 | */ | |
72576341 | 19 | #define pr_fmt(fmt) "trace_kprobe: " fmt |
413d37d1 MH |
20 | |
21 | #include <linux/module.h> | |
22 | #include <linux/uaccess.h> | |
b2d09103 | 23 | #include <linux/rculist.h> |
413d37d1 | 24 | |
8ab83f56 | 25 | #include "trace_probe.h" |
1ff511e3 | 26 | |
8ab83f56 | 27 | #define KPROBE_EVENT_SYSTEM "kprobes" |
696ced4f | 28 | #define KRETPROBE_MAXACTIVE_MAX 4096 |
e09c8614 | 29 | |
413d37d1 | 30 | /** |
77b44d1b | 31 | * Kprobe event core functions |
413d37d1 | 32 | */ |
c31ffb3f | 33 | struct trace_kprobe { |
413d37d1 | 34 | struct list_head list; |
4a846b44 | 35 | struct kretprobe rp; /* Use rp.kp for kprobe use */ |
a7636d9e | 36 | unsigned long __percpu *nhit; |
413d37d1 | 37 | const char *symbol; /* symbol name */ |
c31ffb3f | 38 | struct trace_probe tp; |
413d37d1 MH |
39 | }; |
40 | ||
c31ffb3f NK |
41 | #define SIZEOF_TRACE_KPROBE(n) \ |
42 | (offsetof(struct trace_kprobe, tp.args) + \ | |
eca0d916 | 43 | (sizeof(struct probe_arg) * (n))) |
a82378d8 | 44 | |
93ccae7a | 45 | |
3da0f180 | 46 | static nokprobe_inline bool trace_kprobe_is_return(struct trace_kprobe *tk) |
413d37d1 | 47 | { |
c31ffb3f | 48 | return tk->rp.handler != NULL; |
413d37d1 MH |
49 | } |
50 | ||
3da0f180 | 51 | static nokprobe_inline const char *trace_kprobe_symbol(struct trace_kprobe *tk) |
413d37d1 | 52 | { |
c31ffb3f | 53 | return tk->symbol ? tk->symbol : "unknown"; |
413d37d1 MH |
54 | } |
55 | ||
3da0f180 | 56 | static nokprobe_inline unsigned long trace_kprobe_offset(struct trace_kprobe *tk) |
61424318 | 57 | { |
c31ffb3f | 58 | return tk->rp.kp.offset; |
61424318 MH |
59 | } |
60 | ||
3da0f180 | 61 | static nokprobe_inline bool trace_kprobe_has_gone(struct trace_kprobe *tk) |
61424318 | 62 | { |
c31ffb3f | 63 | return !!(kprobe_gone(&tk->rp.kp)); |
61424318 MH |
64 | } |
65 | ||
3da0f180 | 66 | static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk, |
c31ffb3f | 67 | struct module *mod) |
61424318 MH |
68 | { |
69 | int len = strlen(mod->name); | |
c31ffb3f | 70 | const char *name = trace_kprobe_symbol(tk); |
61424318 MH |
71 | return strncmp(mod->name, name, len) == 0 && name[len] == ':'; |
72 | } | |
73 | ||
3da0f180 | 74 | static nokprobe_inline bool trace_kprobe_is_on_module(struct trace_kprobe *tk) |
61424318 | 75 | { |
c31ffb3f | 76 | return !!strchr(trace_kprobe_symbol(tk), ':'); |
61424318 MH |
77 | } |
78 | ||
f18f97ac MN |
79 | static nokprobe_inline unsigned long trace_kprobe_nhit(struct trace_kprobe *tk) |
80 | { | |
81 | unsigned long nhit = 0; | |
82 | int cpu; | |
83 | ||
84 | for_each_possible_cpu(cpu) | |
85 | nhit += *per_cpu_ptr(tk->nhit, cpu); | |
86 | ||
87 | return nhit; | |
88 | } | |
89 | ||
c31ffb3f NK |
90 | static int register_kprobe_event(struct trace_kprobe *tk); |
91 | static int unregister_kprobe_event(struct trace_kprobe *tk); | |
413d37d1 MH |
92 | |
93 | static DEFINE_MUTEX(probe_lock); | |
94 | static LIST_HEAD(probe_list); | |
95 | ||
50d78056 MH |
96 | static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs); |
97 | static int kretprobe_dispatcher(struct kretprobe_instance *ri, | |
98 | struct pt_regs *regs); | |
99 | ||
1301a44e NK |
100 | /* Memory fetching by symbol */ |
101 | struct symbol_cache { | |
102 | char *symbol; | |
103 | long offset; | |
104 | unsigned long addr; | |
105 | }; | |
106 | ||
107 | unsigned long update_symbol_cache(struct symbol_cache *sc) | |
108 | { | |
109 | sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol); | |
110 | ||
111 | if (sc->addr) | |
112 | sc->addr += sc->offset; | |
113 | ||
114 | return sc->addr; | |
115 | } | |
116 | ||
117 | void free_symbol_cache(struct symbol_cache *sc) | |
118 | { | |
119 | kfree(sc->symbol); | |
120 | kfree(sc); | |
121 | } | |
122 | ||
123 | struct symbol_cache *alloc_symbol_cache(const char *sym, long offset) | |
124 | { | |
125 | struct symbol_cache *sc; | |
126 | ||
127 | if (!sym || strlen(sym) == 0) | |
128 | return NULL; | |
129 | ||
130 | sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL); | |
131 | if (!sc) | |
132 | return NULL; | |
133 | ||
134 | sc->symbol = kstrdup(sym, GFP_KERNEL); | |
135 | if (!sc->symbol) { | |
136 | kfree(sc); | |
137 | return NULL; | |
138 | } | |
139 | sc->offset = offset; | |
140 | update_symbol_cache(sc); | |
141 | ||
142 | return sc; | |
143 | } | |
144 | ||
3fd996a2 NK |
145 | /* |
146 | * Kprobes-specific fetch functions | |
147 | */ | |
148 | #define DEFINE_FETCH_stack(type) \ | |
3da0f180 | 149 | static void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs, \ |
3fd996a2 NK |
150 | void *offset, void *dest) \ |
151 | { \ | |
152 | *(type *)dest = (type)regs_get_kernel_stack_nth(regs, \ | |
153 | (unsigned int)((unsigned long)offset)); \ | |
3da0f180 MH |
154 | } \ |
155 | NOKPROBE_SYMBOL(FETCH_FUNC_NAME(stack, type)); | |
156 | ||
3fd996a2 NK |
157 | DEFINE_BASIC_FETCH_FUNCS(stack) |
158 | /* No string on the stack entry */ | |
159 | #define fetch_stack_string NULL | |
160 | #define fetch_stack_string_size NULL | |
161 | ||
5baaa59e | 162 | #define DEFINE_FETCH_memory(type) \ |
3da0f180 | 163 | static void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs, \ |
5baaa59e NK |
164 | void *addr, void *dest) \ |
165 | { \ | |
166 | type retval; \ | |
167 | if (probe_kernel_address(addr, retval)) \ | |
168 | *(type *)dest = 0; \ | |
169 | else \ | |
170 | *(type *)dest = retval; \ | |
3da0f180 MH |
171 | } \ |
172 | NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, type)); | |
173 | ||
5baaa59e NK |
174 | DEFINE_BASIC_FETCH_FUNCS(memory) |
175 | /* | |
176 | * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max | |
177 | * length and relative data location. | |
178 | */ | |
3da0f180 MH |
179 | static void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs, |
180 | void *addr, void *dest) | |
5baaa59e | 181 | { |
5baaa59e NK |
182 | int maxlen = get_rloc_len(*(u32 *)dest); |
183 | u8 *dst = get_rloc_data(dest); | |
1a6877b9 | 184 | long ret; |
5baaa59e NK |
185 | |
186 | if (!maxlen) | |
187 | return; | |
188 | ||
189 | /* | |
190 | * Try to get string again, since the string can be changed while | |
191 | * probing. | |
192 | */ | |
1a6877b9 | 193 | ret = strncpy_from_unsafe(dst, addr, maxlen); |
5baaa59e NK |
194 | |
195 | if (ret < 0) { /* Failed to fetch string */ | |
1a6877b9 | 196 | dst[0] = '\0'; |
5baaa59e NK |
197 | *(u32 *)dest = make_data_rloc(0, get_rloc_offs(*(u32 *)dest)); |
198 | } else { | |
1a6877b9 | 199 | *(u32 *)dest = make_data_rloc(ret, get_rloc_offs(*(u32 *)dest)); |
5baaa59e NK |
200 | } |
201 | } | |
3da0f180 | 202 | NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, string)); |
5baaa59e NK |
203 | |
204 | /* Return the length of string -- including null terminal byte */ | |
3da0f180 MH |
205 | static void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs, |
206 | void *addr, void *dest) | |
5baaa59e NK |
207 | { |
208 | mm_segment_t old_fs; | |
209 | int ret, len = 0; | |
210 | u8 c; | |
211 | ||
212 | old_fs = get_fs(); | |
213 | set_fs(KERNEL_DS); | |
214 | pagefault_disable(); | |
215 | ||
216 | do { | |
217 | ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1); | |
218 | len++; | |
219 | } while (c && ret == 0 && len < MAX_STRING_SIZE); | |
220 | ||
221 | pagefault_enable(); | |
222 | set_fs(old_fs); | |
223 | ||
224 | if (ret < 0) /* Failed to check the length */ | |
225 | *(u32 *)dest = 0; | |
226 | else | |
227 | *(u32 *)dest = len; | |
228 | } | |
3da0f180 | 229 | NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, string_size)); |
5baaa59e | 230 | |
1301a44e | 231 | #define DEFINE_FETCH_symbol(type) \ |
3da0f180 | 232 | void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs, void *data, void *dest)\ |
1301a44e NK |
233 | { \ |
234 | struct symbol_cache *sc = data; \ | |
235 | if (sc->addr) \ | |
236 | fetch_memory_##type(regs, (void *)sc->addr, dest); \ | |
237 | else \ | |
238 | *(type *)dest = 0; \ | |
3da0f180 MH |
239 | } \ |
240 | NOKPROBE_SYMBOL(FETCH_FUNC_NAME(symbol, type)); | |
241 | ||
1301a44e NK |
242 | DEFINE_BASIC_FETCH_FUNCS(symbol) |
243 | DEFINE_FETCH_symbol(string) | |
244 | DEFINE_FETCH_symbol(string_size) | |
245 | ||
b7e0bf34 NK |
246 | /* kprobes don't support file_offset fetch methods */ |
247 | #define fetch_file_offset_u8 NULL | |
248 | #define fetch_file_offset_u16 NULL | |
249 | #define fetch_file_offset_u32 NULL | |
250 | #define fetch_file_offset_u64 NULL | |
251 | #define fetch_file_offset_string NULL | |
252 | #define fetch_file_offset_string_size NULL | |
253 | ||
34fee3a1 | 254 | /* Fetch type information table */ |
d9a16d3a | 255 | static const struct fetch_type kprobes_fetch_type_table[] = { |
34fee3a1 NK |
256 | /* Special types */ |
257 | [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string, | |
258 | sizeof(u32), 1, "__data_loc char[]"), | |
259 | [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32, | |
260 | string_size, sizeof(u32), 0, "u32"), | |
261 | /* Basic types */ | |
262 | ASSIGN_FETCH_TYPE(u8, u8, 0), | |
263 | ASSIGN_FETCH_TYPE(u16, u16, 0), | |
264 | ASSIGN_FETCH_TYPE(u32, u32, 0), | |
265 | ASSIGN_FETCH_TYPE(u64, u64, 0), | |
266 | ASSIGN_FETCH_TYPE(s8, u8, 1), | |
267 | ASSIGN_FETCH_TYPE(s16, u16, 1), | |
268 | ASSIGN_FETCH_TYPE(s32, u32, 1), | |
269 | ASSIGN_FETCH_TYPE(s64, u64, 1), | |
17ce3dc7 MH |
270 | ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0), |
271 | ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0), | |
272 | ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0), | |
273 | ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0), | |
34fee3a1 NK |
274 | |
275 | ASSIGN_FETCH_TYPE_END | |
276 | }; | |
277 | ||
4a846b44 MH |
278 | /* |
279 | * Allocate new trace_probe and initialize it (including kprobes). | |
280 | */ | |
c31ffb3f | 281 | static struct trace_kprobe *alloc_trace_kprobe(const char *group, |
f52487e9 | 282 | const char *event, |
4a846b44 MH |
283 | void *addr, |
284 | const char *symbol, | |
285 | unsigned long offs, | |
696ced4f | 286 | int maxactive, |
3a6b7666 | 287 | int nargs, bool is_return) |
413d37d1 | 288 | { |
c31ffb3f | 289 | struct trace_kprobe *tk; |
6f3cf440 | 290 | int ret = -ENOMEM; |
413d37d1 | 291 | |
c31ffb3f NK |
292 | tk = kzalloc(SIZEOF_TRACE_KPROBE(nargs), GFP_KERNEL); |
293 | if (!tk) | |
6f3cf440 | 294 | return ERR_PTR(ret); |
413d37d1 | 295 | |
a7636d9e MKL |
296 | tk->nhit = alloc_percpu(unsigned long); |
297 | if (!tk->nhit) | |
298 | goto error; | |
299 | ||
413d37d1 | 300 | if (symbol) { |
c31ffb3f NK |
301 | tk->symbol = kstrdup(symbol, GFP_KERNEL); |
302 | if (!tk->symbol) | |
413d37d1 | 303 | goto error; |
c31ffb3f NK |
304 | tk->rp.kp.symbol_name = tk->symbol; |
305 | tk->rp.kp.offset = offs; | |
4a846b44 | 306 | } else |
c31ffb3f | 307 | tk->rp.kp.addr = addr; |
4a846b44 MH |
308 | |
309 | if (is_return) | |
c31ffb3f | 310 | tk->rp.handler = kretprobe_dispatcher; |
4a846b44 | 311 | else |
c31ffb3f | 312 | tk->rp.kp.pre_handler = kprobe_dispatcher; |
4a846b44 | 313 | |
696ced4f AC |
314 | tk->rp.maxactive = maxactive; |
315 | ||
da34634f | 316 | if (!event || !is_good_name(event)) { |
6f3cf440 | 317 | ret = -EINVAL; |
4263565d | 318 | goto error; |
6f3cf440 MH |
319 | } |
320 | ||
c31ffb3f NK |
321 | tk->tp.call.class = &tk->tp.class; |
322 | tk->tp.call.name = kstrdup(event, GFP_KERNEL); | |
323 | if (!tk->tp.call.name) | |
4263565d | 324 | goto error; |
413d37d1 | 325 | |
da34634f | 326 | if (!group || !is_good_name(group)) { |
6f3cf440 | 327 | ret = -EINVAL; |
f52487e9 | 328 | goto error; |
6f3cf440 MH |
329 | } |
330 | ||
c31ffb3f NK |
331 | tk->tp.class.system = kstrdup(group, GFP_KERNEL); |
332 | if (!tk->tp.class.system) | |
f52487e9 MH |
333 | goto error; |
334 | ||
c31ffb3f NK |
335 | INIT_LIST_HEAD(&tk->list); |
336 | INIT_LIST_HEAD(&tk->tp.files); | |
337 | return tk; | |
413d37d1 | 338 | error: |
c31ffb3f NK |
339 | kfree(tk->tp.call.name); |
340 | kfree(tk->symbol); | |
a7636d9e | 341 | free_percpu(tk->nhit); |
c31ffb3f | 342 | kfree(tk); |
6f3cf440 | 343 | return ERR_PTR(ret); |
413d37d1 MH |
344 | } |
345 | ||
c31ffb3f | 346 | static void free_trace_kprobe(struct trace_kprobe *tk) |
413d37d1 MH |
347 | { |
348 | int i; | |
349 | ||
c31ffb3f NK |
350 | for (i = 0; i < tk->tp.nr_args; i++) |
351 | traceprobe_free_probe_arg(&tk->tp.args[i]); | |
413d37d1 | 352 | |
c31ffb3f NK |
353 | kfree(tk->tp.call.class->system); |
354 | kfree(tk->tp.call.name); | |
355 | kfree(tk->symbol); | |
a7636d9e | 356 | free_percpu(tk->nhit); |
c31ffb3f | 357 | kfree(tk); |
413d37d1 MH |
358 | } |
359 | ||
c31ffb3f NK |
360 | static struct trace_kprobe *find_trace_kprobe(const char *event, |
361 | const char *group) | |
413d37d1 | 362 | { |
c31ffb3f | 363 | struct trace_kprobe *tk; |
413d37d1 | 364 | |
c31ffb3f | 365 | list_for_each_entry(tk, &probe_list, list) |
687fcc4a | 366 | if (strcmp(trace_event_name(&tk->tp.call), event) == 0 && |
c31ffb3f NK |
367 | strcmp(tk->tp.call.class->system, group) == 0) |
368 | return tk; | |
413d37d1 MH |
369 | return NULL; |
370 | } | |
371 | ||
41a7dd42 MH |
372 | /* |
373 | * Enable trace_probe | |
374 | * if the file is NULL, enable "perf" handler, or enable "trace" handler. | |
375 | */ | |
376 | static int | |
7f1d2f82 | 377 | enable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file) |
1538f888 MH |
378 | { |
379 | int ret = 0; | |
380 | ||
41a7dd42 | 381 | if (file) { |
b04d52e3 ON |
382 | struct event_file_link *link; |
383 | ||
384 | link = kmalloc(sizeof(*link), GFP_KERNEL); | |
385 | if (!link) { | |
41a7dd42 | 386 | ret = -ENOMEM; |
3fe3d619 | 387 | goto out; |
41a7dd42 | 388 | } |
41a7dd42 | 389 | |
b04d52e3 | 390 | link->file = file; |
c31ffb3f | 391 | list_add_tail_rcu(&link->list, &tk->tp.files); |
41a7dd42 | 392 | |
c31ffb3f | 393 | tk->tp.flags |= TP_FLAG_TRACE; |
41a7dd42 | 394 | } else |
c31ffb3f | 395 | tk->tp.flags |= TP_FLAG_PROFILE; |
41a7dd42 | 396 | |
c31ffb3f NK |
397 | if (trace_probe_is_registered(&tk->tp) && !trace_kprobe_has_gone(tk)) { |
398 | if (trace_kprobe_is_return(tk)) | |
399 | ret = enable_kretprobe(&tk->rp); | |
1538f888 | 400 | else |
c31ffb3f | 401 | ret = enable_kprobe(&tk->rp.kp); |
1538f888 | 402 | } |
3fe3d619 | 403 | out: |
1538f888 MH |
404 | return ret; |
405 | } | |
406 | ||
41a7dd42 MH |
407 | /* |
408 | * Disable trace_probe | |
409 | * if the file is NULL, disable "perf" handler, or disable "trace" handler. | |
410 | */ | |
411 | static int | |
7f1d2f82 | 412 | disable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file) |
1538f888 | 413 | { |
a232e270 MH |
414 | struct event_file_link *link = NULL; |
415 | int wait = 0; | |
41a7dd42 MH |
416 | int ret = 0; |
417 | ||
41a7dd42 | 418 | if (file) { |
c31ffb3f | 419 | link = find_event_file_link(&tk->tp, file); |
b04d52e3 | 420 | if (!link) { |
41a7dd42 | 421 | ret = -EINVAL; |
3fe3d619 | 422 | goto out; |
41a7dd42 MH |
423 | } |
424 | ||
b04d52e3 | 425 | list_del_rcu(&link->list); |
a232e270 | 426 | wait = 1; |
c31ffb3f | 427 | if (!list_empty(&tk->tp.files)) |
b04d52e3 | 428 | goto out; |
41a7dd42 | 429 | |
c31ffb3f | 430 | tk->tp.flags &= ~TP_FLAG_TRACE; |
41a7dd42 | 431 | } else |
c31ffb3f | 432 | tk->tp.flags &= ~TP_FLAG_PROFILE; |
41a7dd42 | 433 | |
c31ffb3f NK |
434 | if (!trace_probe_is_enabled(&tk->tp) && trace_probe_is_registered(&tk->tp)) { |
435 | if (trace_kprobe_is_return(tk)) | |
436 | disable_kretprobe(&tk->rp); | |
1538f888 | 437 | else |
c31ffb3f | 438 | disable_kprobe(&tk->rp.kp); |
a232e270 | 439 | wait = 1; |
1538f888 | 440 | } |
3fe3d619 | 441 | out: |
a232e270 MH |
442 | if (wait) { |
443 | /* | |
444 | * Synchronize with kprobe_trace_func/kretprobe_trace_func | |
445 | * to ensure disabled (all running handlers are finished). | |
446 | * This is not only for kfree(), but also the caller, | |
447 | * trace_remove_event_call() supposes it for releasing | |
448 | * event_call related objects, which will be accessed in | |
449 | * the kprobe_trace_func/kretprobe_trace_func. | |
450 | */ | |
451 | synchronize_sched(); | |
452 | kfree(link); /* Ignored if link == NULL */ | |
453 | } | |
454 | ||
41a7dd42 | 455 | return ret; |
1538f888 MH |
456 | } |
457 | ||
61424318 | 458 | /* Internal register function - just handle k*probes and flags */ |
c31ffb3f | 459 | static int __register_trace_kprobe(struct trace_kprobe *tk) |
413d37d1 | 460 | { |
7f6878a3 | 461 | int i, ret; |
61424318 | 462 | |
c31ffb3f | 463 | if (trace_probe_is_registered(&tk->tp)) |
61424318 MH |
464 | return -EINVAL; |
465 | ||
c31ffb3f NK |
466 | for (i = 0; i < tk->tp.nr_args; i++) |
467 | traceprobe_update_arg(&tk->tp.args[i]); | |
7f6878a3 | 468 | |
61424318 | 469 | /* Set/clear disabled flag according to tp->flag */ |
c31ffb3f NK |
470 | if (trace_probe_is_enabled(&tk->tp)) |
471 | tk->rp.kp.flags &= ~KPROBE_FLAG_DISABLED; | |
61424318 | 472 | else |
c31ffb3f | 473 | tk->rp.kp.flags |= KPROBE_FLAG_DISABLED; |
61424318 | 474 | |
c31ffb3f NK |
475 | if (trace_kprobe_is_return(tk)) |
476 | ret = register_kretprobe(&tk->rp); | |
413d37d1 | 477 | else |
c31ffb3f | 478 | ret = register_kprobe(&tk->rp.kp); |
61424318 MH |
479 | |
480 | if (ret == 0) | |
c31ffb3f | 481 | tk->tp.flags |= TP_FLAG_REGISTERED; |
61424318 | 482 | else { |
a395d6a7 JP |
483 | pr_warn("Could not insert probe at %s+%lu: %d\n", |
484 | trace_kprobe_symbol(tk), trace_kprobe_offset(tk), ret); | |
c31ffb3f | 485 | if (ret == -ENOENT && trace_kprobe_is_on_module(tk)) { |
a395d6a7 | 486 | pr_warn("This probe might be able to register after target module is loaded. Continue.\n"); |
61424318 MH |
487 | ret = 0; |
488 | } else if (ret == -EILSEQ) { | |
a395d6a7 JP |
489 | pr_warn("Probing address(0x%p) is not an instruction boundary.\n", |
490 | tk->rp.kp.addr); | |
61424318 MH |
491 | ret = -EINVAL; |
492 | } | |
493 | } | |
494 | ||
495 | return ret; | |
496 | } | |
497 | ||
498 | /* Internal unregister function - just handle k*probes and flags */ | |
c31ffb3f | 499 | static void __unregister_trace_kprobe(struct trace_kprobe *tk) |
61424318 | 500 | { |
c31ffb3f NK |
501 | if (trace_probe_is_registered(&tk->tp)) { |
502 | if (trace_kprobe_is_return(tk)) | |
503 | unregister_kretprobe(&tk->rp); | |
61424318 | 504 | else |
c31ffb3f NK |
505 | unregister_kprobe(&tk->rp.kp); |
506 | tk->tp.flags &= ~TP_FLAG_REGISTERED; | |
61424318 | 507 | /* Cleanup kprobe for reuse */ |
c31ffb3f NK |
508 | if (tk->rp.kp.symbol_name) |
509 | tk->rp.kp.addr = NULL; | |
61424318 MH |
510 | } |
511 | } | |
512 | ||
513 | /* Unregister a trace_probe and probe_event: call with locking probe_lock */ | |
c31ffb3f | 514 | static int unregister_trace_kprobe(struct trace_kprobe *tk) |
61424318 | 515 | { |
02ca1521 | 516 | /* Enabled event can not be unregistered */ |
c31ffb3f | 517 | if (trace_probe_is_enabled(&tk->tp)) |
02ca1521 MH |
518 | return -EBUSY; |
519 | ||
40c32592 | 520 | /* Will fail if probe is being used by ftrace or perf */ |
c31ffb3f | 521 | if (unregister_kprobe_event(tk)) |
40c32592 SRRH |
522 | return -EBUSY; |
523 | ||
c31ffb3f NK |
524 | __unregister_trace_kprobe(tk); |
525 | list_del(&tk->list); | |
02ca1521 MH |
526 | |
527 | return 0; | |
413d37d1 MH |
528 | } |
529 | ||
530 | /* Register a trace_probe and probe_event */ | |
c31ffb3f | 531 | static int register_trace_kprobe(struct trace_kprobe *tk) |
413d37d1 | 532 | { |
c31ffb3f | 533 | struct trace_kprobe *old_tk; |
413d37d1 MH |
534 | int ret; |
535 | ||
536 | mutex_lock(&probe_lock); | |
537 | ||
61424318 | 538 | /* Delete old (same name) event if exist */ |
687fcc4a | 539 | old_tk = find_trace_kprobe(trace_event_name(&tk->tp.call), |
de7b2973 | 540 | tk->tp.call.class->system); |
c31ffb3f NK |
541 | if (old_tk) { |
542 | ret = unregister_trace_kprobe(old_tk); | |
02ca1521 MH |
543 | if (ret < 0) |
544 | goto end; | |
c31ffb3f | 545 | free_trace_kprobe(old_tk); |
2d5e067e | 546 | } |
61424318 MH |
547 | |
548 | /* Register new event */ | |
c31ffb3f | 549 | ret = register_kprobe_event(tk); |
2d5e067e | 550 | if (ret) { |
a395d6a7 | 551 | pr_warn("Failed to register probe event(%d)\n", ret); |
2d5e067e MH |
552 | goto end; |
553 | } | |
554 | ||
61424318 | 555 | /* Register k*probe */ |
c31ffb3f | 556 | ret = __register_trace_kprobe(tk); |
61424318 | 557 | if (ret < 0) |
c31ffb3f | 558 | unregister_kprobe_event(tk); |
61424318 | 559 | else |
c31ffb3f | 560 | list_add_tail(&tk->list, &probe_list); |
61424318 | 561 | |
413d37d1 MH |
562 | end: |
563 | mutex_unlock(&probe_lock); | |
564 | return ret; | |
565 | } | |
566 | ||
61424318 | 567 | /* Module notifier call back, checking event on the module */ |
c31ffb3f | 568 | static int trace_kprobe_module_callback(struct notifier_block *nb, |
61424318 MH |
569 | unsigned long val, void *data) |
570 | { | |
571 | struct module *mod = data; | |
c31ffb3f | 572 | struct trace_kprobe *tk; |
61424318 MH |
573 | int ret; |
574 | ||
575 | if (val != MODULE_STATE_COMING) | |
576 | return NOTIFY_DONE; | |
577 | ||
578 | /* Update probes on coming module */ | |
579 | mutex_lock(&probe_lock); | |
c31ffb3f NK |
580 | list_for_each_entry(tk, &probe_list, list) { |
581 | if (trace_kprobe_within_module(tk, mod)) { | |
02ca1521 | 582 | /* Don't need to check busy - this should have gone. */ |
c31ffb3f NK |
583 | __unregister_trace_kprobe(tk); |
584 | ret = __register_trace_kprobe(tk); | |
61424318 | 585 | if (ret) |
a395d6a7 JP |
586 | pr_warn("Failed to re-register probe %s on %s: %d\n", |
587 | trace_event_name(&tk->tp.call), | |
588 | mod->name, ret); | |
61424318 MH |
589 | } |
590 | } | |
591 | mutex_unlock(&probe_lock); | |
592 | ||
593 | return NOTIFY_DONE; | |
594 | } | |
595 | ||
c31ffb3f NK |
596 | static struct notifier_block trace_kprobe_module_nb = { |
597 | .notifier_call = trace_kprobe_module_callback, | |
61424318 MH |
598 | .priority = 1 /* Invoked after kprobe module callback */ |
599 | }; | |
600 | ||
fca18a47 NR |
601 | /* Convert certain expected symbols into '_' when generating event names */ |
602 | static inline void sanitize_event_name(char *name) | |
603 | { | |
604 | while (*name++ != '\0') | |
605 | if (*name == ':' || *name == '.') | |
606 | *name = '_'; | |
607 | } | |
608 | ||
c31ffb3f | 609 | static int create_trace_kprobe(int argc, char **argv) |
413d37d1 MH |
610 | { |
611 | /* | |
612 | * Argument syntax: | |
696ced4f AC |
613 | * - Add kprobe: |
614 | * p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS] | |
615 | * - Add kretprobe: | |
616 | * r[MAXACTIVE][:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS] | |
413d37d1 | 617 | * Fetch args: |
2e06ff63 MH |
618 | * $retval : fetch return value |
619 | * $stack : fetch stack address | |
620 | * $stackN : fetch Nth of stack (N:0-) | |
35abb67d | 621 | * $comm : fetch current task comm |
413d37d1 MH |
622 | * @ADDR : fetch memory at ADDR (ADDR should be in kernel) |
623 | * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol) | |
624 | * %REG : fetch register REG | |
93ccae7a | 625 | * Dereferencing memory fetch: |
413d37d1 | 626 | * +|-offs(ARG) : fetch memory at ARG +|- offs address. |
eca0d916 MH |
627 | * Alias name of args: |
628 | * NAME=FETCHARG : set NAME as alias of FETCHARG. | |
93ccae7a MH |
629 | * Type of args: |
630 | * FETCHARG:TYPE : use TYPE instead of unsigned long. | |
413d37d1 | 631 | */ |
c31ffb3f | 632 | struct trace_kprobe *tk; |
413d37d1 | 633 | int i, ret = 0; |
3a6b7666 | 634 | bool is_return = false, is_delete = false; |
93ccae7a | 635 | char *symbol = NULL, *event = NULL, *group = NULL; |
696ced4f | 636 | int maxactive = 0; |
da34634f | 637 | char *arg; |
2fba0c88 | 638 | unsigned long offset = 0; |
413d37d1 | 639 | void *addr = NULL; |
4a846b44 | 640 | char buf[MAX_EVENT_NAME_LEN]; |
413d37d1 | 641 | |
a7c312be | 642 | /* argc must be >= 1 */ |
413d37d1 | 643 | if (argv[0][0] == 'p') |
3a6b7666 | 644 | is_return = false; |
413d37d1 | 645 | else if (argv[0][0] == 'r') |
3a6b7666 | 646 | is_return = true; |
a7c312be | 647 | else if (argv[0][0] == '-') |
3a6b7666 | 648 | is_delete = true; |
e63cc239 | 649 | else { |
a7c312be MH |
650 | pr_info("Probe definition must be started with 'p', 'r' or" |
651 | " '-'.\n"); | |
413d37d1 | 652 | return -EINVAL; |
e63cc239 | 653 | } |
413d37d1 | 654 | |
696ced4f AC |
655 | event = strchr(&argv[0][1], ':'); |
656 | if (event) { | |
657 | event[0] = '\0'; | |
658 | event++; | |
659 | } | |
660 | if (is_return && isdigit(argv[0][1])) { | |
661 | ret = kstrtouint(&argv[0][1], 0, &maxactive); | |
662 | if (ret) { | |
663 | pr_info("Failed to parse maxactive.\n"); | |
664 | return ret; | |
665 | } | |
666 | /* kretprobes instances are iterated over via a list. The | |
667 | * maximum should stay reasonable. | |
668 | */ | |
669 | if (maxactive > KRETPROBE_MAXACTIVE_MAX) { | |
670 | pr_info("Maxactive is too big (%d > %d).\n", | |
671 | maxactive, KRETPROBE_MAXACTIVE_MAX); | |
672 | return -E2BIG; | |
673 | } | |
674 | } | |
675 | ||
676 | if (event) { | |
f52487e9 MH |
677 | if (strchr(event, '/')) { |
678 | group = event; | |
679 | event = strchr(group, '/') + 1; | |
680 | event[-1] = '\0'; | |
681 | if (strlen(group) == 0) { | |
a5efd925 | 682 | pr_info("Group name is not specified\n"); |
f52487e9 MH |
683 | return -EINVAL; |
684 | } | |
685 | } | |
413d37d1 | 686 | if (strlen(event) == 0) { |
a5efd925 | 687 | pr_info("Event name is not specified\n"); |
413d37d1 MH |
688 | return -EINVAL; |
689 | } | |
690 | } | |
a7c312be MH |
691 | if (!group) |
692 | group = KPROBE_EVENT_SYSTEM; | |
413d37d1 | 693 | |
a7c312be MH |
694 | if (is_delete) { |
695 | if (!event) { | |
696 | pr_info("Delete command needs an event name.\n"); | |
697 | return -EINVAL; | |
698 | } | |
9da79ab8 | 699 | mutex_lock(&probe_lock); |
c31ffb3f NK |
700 | tk = find_trace_kprobe(event, group); |
701 | if (!tk) { | |
9da79ab8 | 702 | mutex_unlock(&probe_lock); |
a7c312be MH |
703 | pr_info("Event %s/%s doesn't exist.\n", group, event); |
704 | return -ENOENT; | |
705 | } | |
706 | /* delete an event */ | |
c31ffb3f | 707 | ret = unregister_trace_kprobe(tk); |
02ca1521 | 708 | if (ret == 0) |
c31ffb3f | 709 | free_trace_kprobe(tk); |
9da79ab8 | 710 | mutex_unlock(&probe_lock); |
02ca1521 | 711 | return ret; |
a7c312be MH |
712 | } |
713 | ||
714 | if (argc < 2) { | |
715 | pr_info("Probe point is not specified.\n"); | |
716 | return -EINVAL; | |
717 | } | |
9e52b325 SD |
718 | |
719 | /* try to parse an address. if that fails, try to read the | |
720 | * input as a symbol. */ | |
721 | if (kstrtoul(argv[1], 0, (unsigned long *)&addr)) { | |
413d37d1 MH |
722 | /* a symbol specified */ |
723 | symbol = argv[1]; | |
724 | /* TODO: support .init module functions */ | |
8ab83f56 | 725 | ret = traceprobe_split_symbol_offset(symbol, &offset); |
e63cc239 | 726 | if (ret) { |
9e52b325 | 727 | pr_info("Failed to parse either an address or a symbol.\n"); |
413d37d1 | 728 | return ret; |
e63cc239 | 729 | } |
d0e02579 | 730 | if (offset && is_return && |
659b957f | 731 | !kprobe_on_func_entry(NULL, symbol, offset)) { |
d0e02579 | 732 | pr_info("Given offset is not valid for return probe.\n"); |
413d37d1 | 733 | return -EINVAL; |
e63cc239 | 734 | } |
413d37d1 | 735 | } |
a82378d8 | 736 | argc -= 2; argv += 2; |
413d37d1 MH |
737 | |
738 | /* setup a probe */ | |
4263565d MH |
739 | if (!event) { |
740 | /* Make a new event name */ | |
4263565d | 741 | if (symbol) |
6f3cf440 | 742 | snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld", |
4263565d MH |
743 | is_return ? 'r' : 'p', symbol, offset); |
744 | else | |
6f3cf440 | 745 | snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p", |
4263565d | 746 | is_return ? 'r' : 'p', addr); |
fca18a47 | 747 | sanitize_event_name(buf); |
4a846b44 MH |
748 | event = buf; |
749 | } | |
696ced4f AC |
750 | tk = alloc_trace_kprobe(group, event, addr, symbol, offset, maxactive, |
751 | argc, is_return); | |
c31ffb3f | 752 | if (IS_ERR(tk)) { |
e63cc239 | 753 | pr_info("Failed to allocate trace_probe.(%d)\n", |
c31ffb3f NK |
754 | (int)PTR_ERR(tk)); |
755 | return PTR_ERR(tk); | |
e63cc239 | 756 | } |
413d37d1 | 757 | |
413d37d1 | 758 | /* parse arguments */ |
a82378d8 MH |
759 | ret = 0; |
760 | for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { | |
c31ffb3f NK |
761 | struct probe_arg *parg = &tk->tp.args[i]; |
762 | ||
61a52736 | 763 | /* Increment count for freeing args in error case */ |
c31ffb3f | 764 | tk->tp.nr_args++; |
61a52736 | 765 | |
eca0d916 MH |
766 | /* Parse argument name */ |
767 | arg = strchr(argv[i], '='); | |
aba91595 | 768 | if (arg) { |
eca0d916 | 769 | *arg++ = '\0'; |
c31ffb3f | 770 | parg->name = kstrdup(argv[i], GFP_KERNEL); |
aba91595 | 771 | } else { |
eca0d916 | 772 | arg = argv[i]; |
aba91595 MH |
773 | /* If argument name is omitted, set "argN" */ |
774 | snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1); | |
c31ffb3f | 775 | parg->name = kstrdup(buf, GFP_KERNEL); |
aba91595 | 776 | } |
a703d946 | 777 | |
c31ffb3f | 778 | if (!parg->name) { |
aba91595 | 779 | pr_info("Failed to allocate argument[%d] name.\n", i); |
ba8665d7 | 780 | ret = -ENOMEM; |
413d37d1 MH |
781 | goto error; |
782 | } | |
da34634f | 783 | |
c31ffb3f | 784 | if (!is_good_name(parg->name)) { |
da34634f | 785 | pr_info("Invalid argument[%d] name: %s\n", |
c31ffb3f | 786 | i, parg->name); |
da34634f MH |
787 | ret = -EINVAL; |
788 | goto error; | |
789 | } | |
93ccae7a | 790 | |
c31ffb3f NK |
791 | if (traceprobe_conflict_field_name(parg->name, |
792 | tk->tp.args, i)) { | |
aba91595 | 793 | pr_info("Argument[%d] name '%s' conflicts with " |
93ccae7a MH |
794 | "another field.\n", i, argv[i]); |
795 | ret = -EINVAL; | |
796 | goto error; | |
797 | } | |
ba8665d7 MH |
798 | |
799 | /* Parse fetch argument */ | |
c31ffb3f | 800 | ret = traceprobe_parse_probe_arg(arg, &tk->tp.size, parg, |
d9a16d3a SR |
801 | is_return, true, |
802 | kprobes_fetch_type_table); | |
e63cc239 | 803 | if (ret) { |
aba91595 | 804 | pr_info("Parse error at argument[%d]. (%d)\n", i, ret); |
413d37d1 | 805 | goto error; |
e63cc239 | 806 | } |
413d37d1 | 807 | } |
413d37d1 | 808 | |
c31ffb3f | 809 | ret = register_trace_kprobe(tk); |
413d37d1 MH |
810 | if (ret) |
811 | goto error; | |
812 | return 0; | |
813 | ||
814 | error: | |
c31ffb3f | 815 | free_trace_kprobe(tk); |
413d37d1 MH |
816 | return ret; |
817 | } | |
818 | ||
c31ffb3f | 819 | static int release_all_trace_kprobes(void) |
413d37d1 | 820 | { |
c31ffb3f | 821 | struct trace_kprobe *tk; |
02ca1521 | 822 | int ret = 0; |
413d37d1 MH |
823 | |
824 | mutex_lock(&probe_lock); | |
02ca1521 | 825 | /* Ensure no probe is in use. */ |
c31ffb3f NK |
826 | list_for_each_entry(tk, &probe_list, list) |
827 | if (trace_probe_is_enabled(&tk->tp)) { | |
02ca1521 MH |
828 | ret = -EBUSY; |
829 | goto end; | |
830 | } | |
413d37d1 MH |
831 | /* TODO: Use batch unregistration */ |
832 | while (!list_empty(&probe_list)) { | |
c31ffb3f NK |
833 | tk = list_entry(probe_list.next, struct trace_kprobe, list); |
834 | ret = unregister_trace_kprobe(tk); | |
40c32592 SRRH |
835 | if (ret) |
836 | goto end; | |
c31ffb3f | 837 | free_trace_kprobe(tk); |
413d37d1 | 838 | } |
02ca1521 MH |
839 | |
840 | end: | |
413d37d1 | 841 | mutex_unlock(&probe_lock); |
02ca1521 MH |
842 | |
843 | return ret; | |
413d37d1 MH |
844 | } |
845 | ||
413d37d1 MH |
846 | /* Probes listing interfaces */ |
847 | static void *probes_seq_start(struct seq_file *m, loff_t *pos) | |
848 | { | |
849 | mutex_lock(&probe_lock); | |
850 | return seq_list_start(&probe_list, *pos); | |
851 | } | |
852 | ||
853 | static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos) | |
854 | { | |
855 | return seq_list_next(v, &probe_list, pos); | |
856 | } | |
857 | ||
858 | static void probes_seq_stop(struct seq_file *m, void *v) | |
859 | { | |
860 | mutex_unlock(&probe_lock); | |
861 | } | |
862 | ||
863 | static int probes_seq_show(struct seq_file *m, void *v) | |
864 | { | |
c31ffb3f | 865 | struct trace_kprobe *tk = v; |
93ccae7a | 866 | int i; |
413d37d1 | 867 | |
fa6f0cc7 | 868 | seq_putc(m, trace_kprobe_is_return(tk) ? 'r' : 'p'); |
de7b2973 | 869 | seq_printf(m, ":%s/%s", tk->tp.call.class->system, |
687fcc4a | 870 | trace_event_name(&tk->tp.call)); |
413d37d1 | 871 | |
c31ffb3f NK |
872 | if (!tk->symbol) |
873 | seq_printf(m, " 0x%p", tk->rp.kp.addr); | |
874 | else if (tk->rp.kp.offset) | |
875 | seq_printf(m, " %s+%u", trace_kprobe_symbol(tk), | |
876 | tk->rp.kp.offset); | |
413d37d1 | 877 | else |
c31ffb3f | 878 | seq_printf(m, " %s", trace_kprobe_symbol(tk)); |
413d37d1 | 879 | |
c31ffb3f NK |
880 | for (i = 0; i < tk->tp.nr_args; i++) |
881 | seq_printf(m, " %s=%s", tk->tp.args[i].name, tk->tp.args[i].comm); | |
fa6f0cc7 | 882 | seq_putc(m, '\n'); |
93ccae7a | 883 | |
413d37d1 MH |
884 | return 0; |
885 | } | |
886 | ||
887 | static const struct seq_operations probes_seq_op = { | |
888 | .start = probes_seq_start, | |
889 | .next = probes_seq_next, | |
890 | .stop = probes_seq_stop, | |
891 | .show = probes_seq_show | |
892 | }; | |
893 | ||
894 | static int probes_open(struct inode *inode, struct file *file) | |
895 | { | |
02ca1521 MH |
896 | int ret; |
897 | ||
898 | if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { | |
c31ffb3f | 899 | ret = release_all_trace_kprobes(); |
02ca1521 MH |
900 | if (ret < 0) |
901 | return ret; | |
902 | } | |
413d37d1 MH |
903 | |
904 | return seq_open(file, &probes_seq_op); | |
905 | } | |
906 | ||
413d37d1 MH |
907 | static ssize_t probes_write(struct file *file, const char __user *buffer, |
908 | size_t count, loff_t *ppos) | |
909 | { | |
7e465baa TZ |
910 | return trace_parse_run_command(file, buffer, count, ppos, |
911 | create_trace_kprobe); | |
413d37d1 MH |
912 | } |
913 | ||
914 | static const struct file_operations kprobe_events_ops = { | |
915 | .owner = THIS_MODULE, | |
916 | .open = probes_open, | |
917 | .read = seq_read, | |
918 | .llseek = seq_lseek, | |
919 | .release = seq_release, | |
920 | .write = probes_write, | |
921 | }; | |
922 | ||
cd7e7bd5 MH |
923 | /* Probes profiling interfaces */ |
924 | static int probes_profile_seq_show(struct seq_file *m, void *v) | |
925 | { | |
c31ffb3f | 926 | struct trace_kprobe *tk = v; |
cd7e7bd5 | 927 | |
de7b2973 | 928 | seq_printf(m, " %-44s %15lu %15lu\n", |
f18f97ac MN |
929 | trace_event_name(&tk->tp.call), |
930 | trace_kprobe_nhit(tk), | |
c31ffb3f | 931 | tk->rp.kp.nmissed); |
cd7e7bd5 MH |
932 | |
933 | return 0; | |
934 | } | |
935 | ||
936 | static const struct seq_operations profile_seq_op = { | |
937 | .start = probes_seq_start, | |
938 | .next = probes_seq_next, | |
939 | .stop = probes_seq_stop, | |
940 | .show = probes_profile_seq_show | |
941 | }; | |
942 | ||
943 | static int profile_open(struct inode *inode, struct file *file) | |
944 | { | |
945 | return seq_open(file, &profile_seq_op); | |
946 | } | |
947 | ||
948 | static const struct file_operations kprobe_profile_ops = { | |
949 | .owner = THIS_MODULE, | |
950 | .open = profile_open, | |
951 | .read = seq_read, | |
952 | .llseek = seq_lseek, | |
953 | .release = seq_release, | |
954 | }; | |
955 | ||
413d37d1 | 956 | /* Kprobe handler */ |
3da0f180 | 957 | static nokprobe_inline void |
c31ffb3f | 958 | __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs, |
7f1d2f82 | 959 | struct trace_event_file *trace_file) |
413d37d1 | 960 | { |
93ccae7a | 961 | struct kprobe_trace_entry_head *entry; |
413d37d1 | 962 | struct ring_buffer_event *event; |
8f8ffe24 | 963 | struct ring_buffer *buffer; |
e09c8614 | 964 | int size, dsize, pc; |
413d37d1 | 965 | unsigned long irq_flags; |
2425bcb9 | 966 | struct trace_event_call *call = &tk->tp.call; |
413d37d1 | 967 | |
7f1d2f82 | 968 | WARN_ON(call != trace_file->event_call); |
41a7dd42 | 969 | |
09a5059a | 970 | if (trace_trigger_soft_disabled(trace_file)) |
13a1e4ae | 971 | return; |
b8820084 | 972 | |
413d37d1 MH |
973 | local_save_flags(irq_flags); |
974 | pc = preempt_count(); | |
975 | ||
c31ffb3f NK |
976 | dsize = __get_data_size(&tk->tp, regs); |
977 | size = sizeof(*entry) + tk->tp.size + dsize; | |
413d37d1 | 978 | |
7f1d2f82 | 979 | event = trace_event_buffer_lock_reserve(&buffer, trace_file, |
41a7dd42 MH |
980 | call->event.type, |
981 | size, irq_flags, pc); | |
413d37d1 | 982 | if (!event) |
1e12a4a7 | 983 | return; |
413d37d1 MH |
984 | |
985 | entry = ring_buffer_event_data(event); | |
c31ffb3f NK |
986 | entry->ip = (unsigned long)tk->rp.kp.addr; |
987 | store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize); | |
413d37d1 | 988 | |
7f1d2f82 | 989 | event_trigger_unlock_commit_regs(trace_file, buffer, event, |
13a1e4ae | 990 | entry, irq_flags, pc, regs); |
413d37d1 MH |
991 | } |
992 | ||
3da0f180 | 993 | static void |
c31ffb3f | 994 | kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs) |
41a7dd42 | 995 | { |
b04d52e3 | 996 | struct event_file_link *link; |
41a7dd42 | 997 | |
c31ffb3f NK |
998 | list_for_each_entry_rcu(link, &tk->tp.files, list) |
999 | __kprobe_trace_func(tk, regs, link->file); | |
41a7dd42 | 1000 | } |
3da0f180 | 1001 | NOKPROBE_SYMBOL(kprobe_trace_func); |
41a7dd42 | 1002 | |
413d37d1 | 1003 | /* Kretprobe handler */ |
3da0f180 | 1004 | static nokprobe_inline void |
c31ffb3f | 1005 | __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, |
41a7dd42 | 1006 | struct pt_regs *regs, |
7f1d2f82 | 1007 | struct trace_event_file *trace_file) |
413d37d1 | 1008 | { |
93ccae7a | 1009 | struct kretprobe_trace_entry_head *entry; |
413d37d1 | 1010 | struct ring_buffer_event *event; |
8f8ffe24 | 1011 | struct ring_buffer *buffer; |
e09c8614 | 1012 | int size, pc, dsize; |
413d37d1 | 1013 | unsigned long irq_flags; |
2425bcb9 | 1014 | struct trace_event_call *call = &tk->tp.call; |
413d37d1 | 1015 | |
7f1d2f82 | 1016 | WARN_ON(call != trace_file->event_call); |
41a7dd42 | 1017 | |
09a5059a | 1018 | if (trace_trigger_soft_disabled(trace_file)) |
13a1e4ae | 1019 | return; |
b8820084 | 1020 | |
413d37d1 MH |
1021 | local_save_flags(irq_flags); |
1022 | pc = preempt_count(); | |
1023 | ||
c31ffb3f NK |
1024 | dsize = __get_data_size(&tk->tp, regs); |
1025 | size = sizeof(*entry) + tk->tp.size + dsize; | |
413d37d1 | 1026 | |
7f1d2f82 | 1027 | event = trace_event_buffer_lock_reserve(&buffer, trace_file, |
41a7dd42 MH |
1028 | call->event.type, |
1029 | size, irq_flags, pc); | |
413d37d1 | 1030 | if (!event) |
1e12a4a7 | 1031 | return; |
413d37d1 MH |
1032 | |
1033 | entry = ring_buffer_event_data(event); | |
c31ffb3f | 1034 | entry->func = (unsigned long)tk->rp.kp.addr; |
413d37d1 | 1035 | entry->ret_ip = (unsigned long)ri->ret_addr; |
c31ffb3f | 1036 | store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize); |
413d37d1 | 1037 | |
7f1d2f82 | 1038 | event_trigger_unlock_commit_regs(trace_file, buffer, event, |
13a1e4ae | 1039 | entry, irq_flags, pc, regs); |
413d37d1 MH |
1040 | } |
1041 | ||
3da0f180 | 1042 | static void |
c31ffb3f | 1043 | kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, |
41a7dd42 MH |
1044 | struct pt_regs *regs) |
1045 | { | |
b04d52e3 | 1046 | struct event_file_link *link; |
41a7dd42 | 1047 | |
c31ffb3f NK |
1048 | list_for_each_entry_rcu(link, &tk->tp.files, list) |
1049 | __kretprobe_trace_func(tk, ri, regs, link->file); | |
41a7dd42 | 1050 | } |
3da0f180 | 1051 | NOKPROBE_SYMBOL(kretprobe_trace_func); |
41a7dd42 | 1052 | |
413d37d1 | 1053 | /* Event entry printers */ |
b62fdd97 | 1054 | static enum print_line_t |
a9a57763 SR |
1055 | print_kprobe_event(struct trace_iterator *iter, int flags, |
1056 | struct trace_event *event) | |
413d37d1 | 1057 | { |
93ccae7a | 1058 | struct kprobe_trace_entry_head *field; |
413d37d1 | 1059 | struct trace_seq *s = &iter->seq; |
eca0d916 | 1060 | struct trace_probe *tp; |
93ccae7a | 1061 | u8 *data; |
413d37d1 MH |
1062 | int i; |
1063 | ||
93ccae7a | 1064 | field = (struct kprobe_trace_entry_head *)iter->ent; |
80decc70 | 1065 | tp = container_of(event, struct trace_probe, call.event); |
413d37d1 | 1066 | |
687fcc4a | 1067 | trace_seq_printf(s, "%s: (", trace_event_name(&tp->call)); |
6e9f23d1 | 1068 | |
413d37d1 | 1069 | if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET)) |
85224da0 | 1070 | goto out; |
413d37d1 | 1071 | |
85224da0 | 1072 | trace_seq_putc(s, ')'); |
413d37d1 | 1073 | |
93ccae7a MH |
1074 | data = (u8 *)&field[1]; |
1075 | for (i = 0; i < tp->nr_args; i++) | |
1076 | if (!tp->args[i].type->print(s, tp->args[i].name, | |
e09c8614 | 1077 | data + tp->args[i].offset, field)) |
85224da0 | 1078 | goto out; |
413d37d1 | 1079 | |
85224da0 SRRH |
1080 | trace_seq_putc(s, '\n'); |
1081 | out: | |
1082 | return trace_handle_return(s); | |
413d37d1 MH |
1083 | } |
1084 | ||
b62fdd97 | 1085 | static enum print_line_t |
a9a57763 SR |
1086 | print_kretprobe_event(struct trace_iterator *iter, int flags, |
1087 | struct trace_event *event) | |
413d37d1 | 1088 | { |
93ccae7a | 1089 | struct kretprobe_trace_entry_head *field; |
413d37d1 | 1090 | struct trace_seq *s = &iter->seq; |
eca0d916 | 1091 | struct trace_probe *tp; |
93ccae7a | 1092 | u8 *data; |
413d37d1 MH |
1093 | int i; |
1094 | ||
93ccae7a | 1095 | field = (struct kretprobe_trace_entry_head *)iter->ent; |
80decc70 | 1096 | tp = container_of(event, struct trace_probe, call.event); |
413d37d1 | 1097 | |
687fcc4a | 1098 | trace_seq_printf(s, "%s: (", trace_event_name(&tp->call)); |
6e9f23d1 | 1099 | |
413d37d1 | 1100 | if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET)) |
85224da0 | 1101 | goto out; |
413d37d1 | 1102 | |
85224da0 | 1103 | trace_seq_puts(s, " <- "); |
413d37d1 MH |
1104 | |
1105 | if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET)) | |
85224da0 | 1106 | goto out; |
413d37d1 | 1107 | |
85224da0 | 1108 | trace_seq_putc(s, ')'); |
413d37d1 | 1109 | |
93ccae7a MH |
1110 | data = (u8 *)&field[1]; |
1111 | for (i = 0; i < tp->nr_args; i++) | |
1112 | if (!tp->args[i].type->print(s, tp->args[i].name, | |
e09c8614 | 1113 | data + tp->args[i].offset, field)) |
85224da0 | 1114 | goto out; |
413d37d1 | 1115 | |
85224da0 | 1116 | trace_seq_putc(s, '\n'); |
413d37d1 | 1117 | |
85224da0 SRRH |
1118 | out: |
1119 | return trace_handle_return(s); | |
413d37d1 MH |
1120 | } |
1121 | ||
413d37d1 | 1122 | |
2425bcb9 | 1123 | static int kprobe_event_define_fields(struct trace_event_call *event_call) |
413d37d1 MH |
1124 | { |
1125 | int ret, i; | |
93ccae7a | 1126 | struct kprobe_trace_entry_head field; |
c31ffb3f | 1127 | struct trace_kprobe *tk = (struct trace_kprobe *)event_call->data; |
413d37d1 | 1128 | |
a703d946 | 1129 | DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0); |
eca0d916 | 1130 | /* Set argument names as fields */ |
c31ffb3f NK |
1131 | for (i = 0; i < tk->tp.nr_args; i++) { |
1132 | struct probe_arg *parg = &tk->tp.args[i]; | |
1133 | ||
1134 | ret = trace_define_field(event_call, parg->type->fmttype, | |
1135 | parg->name, | |
1136 | sizeof(field) + parg->offset, | |
1137 | parg->type->size, | |
1138 | parg->type->is_signed, | |
93ccae7a MH |
1139 | FILTER_OTHER); |
1140 | if (ret) | |
1141 | return ret; | |
1142 | } | |
413d37d1 MH |
1143 | return 0; |
1144 | } | |
1145 | ||
2425bcb9 | 1146 | static int kretprobe_event_define_fields(struct trace_event_call *event_call) |
413d37d1 MH |
1147 | { |
1148 | int ret, i; | |
93ccae7a | 1149 | struct kretprobe_trace_entry_head field; |
c31ffb3f | 1150 | struct trace_kprobe *tk = (struct trace_kprobe *)event_call->data; |
413d37d1 | 1151 | |
a703d946 MH |
1152 | DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0); |
1153 | DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0); | |
eca0d916 | 1154 | /* Set argument names as fields */ |
c31ffb3f NK |
1155 | for (i = 0; i < tk->tp.nr_args; i++) { |
1156 | struct probe_arg *parg = &tk->tp.args[i]; | |
1157 | ||
1158 | ret = trace_define_field(event_call, parg->type->fmttype, | |
1159 | parg->name, | |
1160 | sizeof(field) + parg->offset, | |
1161 | parg->type->size, | |
1162 | parg->type->is_signed, | |
93ccae7a MH |
1163 | FILTER_OTHER); |
1164 | if (ret) | |
1165 | return ret; | |
1166 | } | |
413d37d1 MH |
1167 | return 0; |
1168 | } | |
1169 | ||
07b139c8 | 1170 | #ifdef CONFIG_PERF_EVENTS |
e08d1c65 MH |
1171 | |
1172 | /* Kprobe profile handler */ | |
3da0f180 | 1173 | static void |
c31ffb3f | 1174 | kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs) |
e08d1c65 | 1175 | { |
2425bcb9 | 1176 | struct trace_event_call *call = &tk->tp.call; |
2541517c | 1177 | struct bpf_prog *prog = call->prog; |
93ccae7a | 1178 | struct kprobe_trace_entry_head *entry; |
1c024eca | 1179 | struct hlist_head *head; |
e09c8614 | 1180 | int size, __size, dsize; |
4ed7c92d | 1181 | int rctx; |
e08d1c65 | 1182 | |
2541517c AS |
1183 | if (prog && !trace_call_bpf(prog, regs)) |
1184 | return; | |
1185 | ||
288e984e ON |
1186 | head = this_cpu_ptr(call->perf_events); |
1187 | if (hlist_empty(head)) | |
1188 | return; | |
1189 | ||
c31ffb3f NK |
1190 | dsize = __get_data_size(&tk->tp, regs); |
1191 | __size = sizeof(*entry) + tk->tp.size + dsize; | |
74ebb63e MH |
1192 | size = ALIGN(__size + sizeof(u32), sizeof(u64)); |
1193 | size -= sizeof(u32); | |
ce71b9df | 1194 | |
1e1dcd93 | 1195 | entry = perf_trace_buf_alloc(size, NULL, &rctx); |
430ad5a6 | 1196 | if (!entry) |
1e12a4a7 | 1197 | return; |
a1a138d0 | 1198 | |
c31ffb3f | 1199 | entry->ip = (unsigned long)tk->rp.kp.addr; |
e09c8614 | 1200 | memset(&entry[1], 0, dsize); |
c31ffb3f | 1201 | store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize); |
1e1dcd93 | 1202 | perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, |
75e83876 | 1203 | head, NULL, NULL); |
e08d1c65 | 1204 | } |
3da0f180 | 1205 | NOKPROBE_SYMBOL(kprobe_perf_func); |
e08d1c65 MH |
1206 | |
1207 | /* Kretprobe profile handler */ | |
3da0f180 | 1208 | static void |
c31ffb3f | 1209 | kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, |
2b106aab | 1210 | struct pt_regs *regs) |
e08d1c65 | 1211 | { |
2425bcb9 | 1212 | struct trace_event_call *call = &tk->tp.call; |
2541517c | 1213 | struct bpf_prog *prog = call->prog; |
93ccae7a | 1214 | struct kretprobe_trace_entry_head *entry; |
1c024eca | 1215 | struct hlist_head *head; |
e09c8614 | 1216 | int size, __size, dsize; |
4ed7c92d | 1217 | int rctx; |
e08d1c65 | 1218 | |
2541517c AS |
1219 | if (prog && !trace_call_bpf(prog, regs)) |
1220 | return; | |
1221 | ||
288e984e ON |
1222 | head = this_cpu_ptr(call->perf_events); |
1223 | if (hlist_empty(head)) | |
1224 | return; | |
1225 | ||
c31ffb3f NK |
1226 | dsize = __get_data_size(&tk->tp, regs); |
1227 | __size = sizeof(*entry) + tk->tp.size + dsize; | |
74ebb63e MH |
1228 | size = ALIGN(__size + sizeof(u32), sizeof(u64)); |
1229 | size -= sizeof(u32); | |
444a2a3b | 1230 | |
1e1dcd93 | 1231 | entry = perf_trace_buf_alloc(size, NULL, &rctx); |
430ad5a6 | 1232 | if (!entry) |
1e12a4a7 | 1233 | return; |
e08d1c65 | 1234 | |
c31ffb3f | 1235 | entry->func = (unsigned long)tk->rp.kp.addr; |
a1a138d0 | 1236 | entry->ret_ip = (unsigned long)ri->ret_addr; |
c31ffb3f | 1237 | store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize); |
1e1dcd93 | 1238 | perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, |
75e83876 | 1239 | head, NULL, NULL); |
e08d1c65 | 1240 | } |
3da0f180 | 1241 | NOKPROBE_SYMBOL(kretprobe_perf_func); |
07b139c8 | 1242 | #endif /* CONFIG_PERF_EVENTS */ |
50d78056 | 1243 | |
3fe3d619 ON |
1244 | /* |
1245 | * called by perf_trace_init() or __ftrace_set_clr_event() under event_mutex. | |
1246 | * | |
1247 | * kprobe_trace_self_tests_init() does enable_trace_probe/disable_trace_probe | |
1248 | * lockless, but we can't race with this __init function. | |
1249 | */ | |
2425bcb9 | 1250 | static int kprobe_register(struct trace_event_call *event, |
fbc1963d | 1251 | enum trace_reg type, void *data) |
2239291a | 1252 | { |
c31ffb3f | 1253 | struct trace_kprobe *tk = (struct trace_kprobe *)event->data; |
7f1d2f82 | 1254 | struct trace_event_file *file = data; |
1538f888 | 1255 | |
2239291a SR |
1256 | switch (type) { |
1257 | case TRACE_REG_REGISTER: | |
c31ffb3f | 1258 | return enable_trace_kprobe(tk, file); |
2239291a | 1259 | case TRACE_REG_UNREGISTER: |
c31ffb3f | 1260 | return disable_trace_kprobe(tk, file); |
2239291a SR |
1261 | |
1262 | #ifdef CONFIG_PERF_EVENTS | |
1263 | case TRACE_REG_PERF_REGISTER: | |
c31ffb3f | 1264 | return enable_trace_kprobe(tk, NULL); |
2239291a | 1265 | case TRACE_REG_PERF_UNREGISTER: |
c31ffb3f | 1266 | return disable_trace_kprobe(tk, NULL); |
ceec0b6f JO |
1267 | case TRACE_REG_PERF_OPEN: |
1268 | case TRACE_REG_PERF_CLOSE: | |
489c75c3 JO |
1269 | case TRACE_REG_PERF_ADD: |
1270 | case TRACE_REG_PERF_DEL: | |
ceec0b6f | 1271 | return 0; |
2239291a SR |
1272 | #endif |
1273 | } | |
1274 | return 0; | |
1275 | } | |
50d78056 | 1276 | |
3da0f180 | 1277 | static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs) |
50d78056 | 1278 | { |
c31ffb3f | 1279 | struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp); |
e08d1c65 | 1280 | |
a7636d9e | 1281 | raw_cpu_inc(*tk->nhit); |
48182bd2 | 1282 | |
c31ffb3f NK |
1283 | if (tk->tp.flags & TP_FLAG_TRACE) |
1284 | kprobe_trace_func(tk, regs); | |
07b139c8 | 1285 | #ifdef CONFIG_PERF_EVENTS |
c31ffb3f NK |
1286 | if (tk->tp.flags & TP_FLAG_PROFILE) |
1287 | kprobe_perf_func(tk, regs); | |
07b139c8 | 1288 | #endif |
50d78056 MH |
1289 | return 0; /* We don't tweek kernel, so just return 0 */ |
1290 | } | |
3da0f180 | 1291 | NOKPROBE_SYMBOL(kprobe_dispatcher); |
50d78056 | 1292 | |
3da0f180 MH |
1293 | static int |
1294 | kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs) | |
50d78056 | 1295 | { |
c31ffb3f | 1296 | struct trace_kprobe *tk = container_of(ri->rp, struct trace_kprobe, rp); |
50d78056 | 1297 | |
a7636d9e | 1298 | raw_cpu_inc(*tk->nhit); |
48182bd2 | 1299 | |
c31ffb3f NK |
1300 | if (tk->tp.flags & TP_FLAG_TRACE) |
1301 | kretprobe_trace_func(tk, ri, regs); | |
07b139c8 | 1302 | #ifdef CONFIG_PERF_EVENTS |
c31ffb3f NK |
1303 | if (tk->tp.flags & TP_FLAG_PROFILE) |
1304 | kretprobe_perf_func(tk, ri, regs); | |
07b139c8 | 1305 | #endif |
50d78056 MH |
1306 | return 0; /* We don't tweek kernel, so just return 0 */ |
1307 | } | |
3da0f180 | 1308 | NOKPROBE_SYMBOL(kretprobe_dispatcher); |
e08d1c65 | 1309 | |
a9a57763 SR |
1310 | static struct trace_event_functions kretprobe_funcs = { |
1311 | .trace = print_kretprobe_event | |
1312 | }; | |
1313 | ||
1314 | static struct trace_event_functions kprobe_funcs = { | |
1315 | .trace = print_kprobe_event | |
1316 | }; | |
1317 | ||
c31ffb3f | 1318 | static int register_kprobe_event(struct trace_kprobe *tk) |
413d37d1 | 1319 | { |
2425bcb9 | 1320 | struct trace_event_call *call = &tk->tp.call; |
413d37d1 MH |
1321 | int ret; |
1322 | ||
2425bcb9 | 1323 | /* Initialize trace_event_call */ |
ffb9f995 | 1324 | INIT_LIST_HEAD(&call->class->fields); |
c31ffb3f | 1325 | if (trace_kprobe_is_return(tk)) { |
80decc70 | 1326 | call->event.funcs = &kretprobe_funcs; |
2e33af02 | 1327 | call->class->define_fields = kretprobe_event_define_fields; |
413d37d1 | 1328 | } else { |
80decc70 | 1329 | call->event.funcs = &kprobe_funcs; |
2e33af02 | 1330 | call->class->define_fields = kprobe_event_define_fields; |
413d37d1 | 1331 | } |
5bf652aa | 1332 | if (set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) |
a342a028 | 1333 | return -ENOMEM; |
9023c930 | 1334 | ret = register_trace_event(&call->event); |
32c0edae | 1335 | if (!ret) { |
a342a028 | 1336 | kfree(call->print_fmt); |
ff50d991 | 1337 | return -ENODEV; |
a342a028 | 1338 | } |
72cbbc89 | 1339 | call->flags = TRACE_EVENT_FL_KPROBE; |
2239291a | 1340 | call->class->reg = kprobe_register; |
c31ffb3f | 1341 | call->data = tk; |
413d37d1 | 1342 | ret = trace_add_event_call(call); |
ff50d991 | 1343 | if (ret) { |
de7b2973 | 1344 | pr_info("Failed to register kprobe event: %s\n", |
687fcc4a | 1345 | trace_event_name(call)); |
a342a028 | 1346 | kfree(call->print_fmt); |
9023c930 | 1347 | unregister_trace_event(&call->event); |
ff50d991 | 1348 | } |
413d37d1 MH |
1349 | return ret; |
1350 | } | |
1351 | ||
c31ffb3f | 1352 | static int unregister_kprobe_event(struct trace_kprobe *tk) |
413d37d1 | 1353 | { |
40c32592 SRRH |
1354 | int ret; |
1355 | ||
ff50d991 | 1356 | /* tp->event is unregistered in trace_remove_event_call() */ |
c31ffb3f | 1357 | ret = trace_remove_event_call(&tk->tp.call); |
40c32592 | 1358 | if (!ret) |
c31ffb3f | 1359 | kfree(tk->tp.call.print_fmt); |
40c32592 | 1360 | return ret; |
413d37d1 MH |
1361 | } |
1362 | ||
8434dc93 | 1363 | /* Make a tracefs interface for controlling probe points */ |
413d37d1 MH |
1364 | static __init int init_kprobe_trace(void) |
1365 | { | |
1366 | struct dentry *d_tracer; | |
1367 | struct dentry *entry; | |
413d37d1 | 1368 | |
c31ffb3f | 1369 | if (register_module_notifier(&trace_kprobe_module_nb)) |
61424318 MH |
1370 | return -EINVAL; |
1371 | ||
413d37d1 | 1372 | d_tracer = tracing_init_dentry(); |
14a5ae40 | 1373 | if (IS_ERR(d_tracer)) |
413d37d1 MH |
1374 | return 0; |
1375 | ||
8434dc93 | 1376 | entry = tracefs_create_file("kprobe_events", 0644, d_tracer, |
413d37d1 MH |
1377 | NULL, &kprobe_events_ops); |
1378 | ||
cd7e7bd5 | 1379 | /* Event list interface */ |
413d37d1 | 1380 | if (!entry) |
a395d6a7 | 1381 | pr_warn("Could not create tracefs 'kprobe_events' entry\n"); |
cd7e7bd5 MH |
1382 | |
1383 | /* Profile interface */ | |
8434dc93 | 1384 | entry = tracefs_create_file("kprobe_profile", 0444, d_tracer, |
cd7e7bd5 MH |
1385 | NULL, &kprobe_profile_ops); |
1386 | ||
1387 | if (!entry) | |
a395d6a7 | 1388 | pr_warn("Could not create tracefs 'kprobe_profile' entry\n"); |
413d37d1 MH |
1389 | return 0; |
1390 | } | |
1391 | fs_initcall(init_kprobe_trace); | |
1392 | ||
1393 | ||
1394 | #ifdef CONFIG_FTRACE_STARTUP_TEST | |
265a5b7e SR |
1395 | /* |
1396 | * The "__used" keeps gcc from removing the function symbol | |
d4d7ccc8 MN |
1397 | * from the kallsyms table. 'noinline' makes sure that there |
1398 | * isn't an inlined version used by the test method below | |
265a5b7e | 1399 | */ |
d4d7ccc8 MN |
1400 | static __used __init noinline int |
1401 | kprobe_trace_selftest_target(int a1, int a2, int a3, int a4, int a5, int a6) | |
413d37d1 MH |
1402 | { |
1403 | return a1 + a2 + a3 + a4 + a5 + a6; | |
1404 | } | |
1405 | ||
26a346f2 | 1406 | static __init struct trace_event_file * |
c31ffb3f | 1407 | find_trace_probe_file(struct trace_kprobe *tk, struct trace_array *tr) |
41a7dd42 | 1408 | { |
7f1d2f82 | 1409 | struct trace_event_file *file; |
41a7dd42 MH |
1410 | |
1411 | list_for_each_entry(file, &tr->events, list) | |
c31ffb3f | 1412 | if (file->event_call == &tk->tp.call) |
41a7dd42 MH |
1413 | return file; |
1414 | ||
1415 | return NULL; | |
1416 | } | |
1417 | ||
3fe3d619 | 1418 | /* |
c31ffb3f | 1419 | * Nobody but us can call enable_trace_kprobe/disable_trace_kprobe at this |
3fe3d619 ON |
1420 | * stage, we can do this lockless. |
1421 | */ | |
413d37d1 MH |
1422 | static __init int kprobe_trace_self_tests_init(void) |
1423 | { | |
231e36f4 | 1424 | int ret, warn = 0; |
413d37d1 | 1425 | int (*target)(int, int, int, int, int, int); |
c31ffb3f | 1426 | struct trace_kprobe *tk; |
7f1d2f82 | 1427 | struct trace_event_file *file; |
413d37d1 | 1428 | |
748ec3a2 YY |
1429 | if (tracing_is_disabled()) |
1430 | return -ENODEV; | |
1431 | ||
413d37d1 MH |
1432 | target = kprobe_trace_selftest_target; |
1433 | ||
1434 | pr_info("Testing kprobe tracing: "); | |
1435 | ||
7e465baa TZ |
1436 | ret = trace_run_command("p:testprobe kprobe_trace_selftest_target " |
1437 | "$stack $stack0 +0($stack)", | |
1438 | create_trace_kprobe); | |
231e36f4 | 1439 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1440 | pr_warn("error on probing function entry.\n"); |
231e36f4 MH |
1441 | warn++; |
1442 | } else { | |
1443 | /* Enable trace point */ | |
c31ffb3f NK |
1444 | tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM); |
1445 | if (WARN_ON_ONCE(tk == NULL)) { | |
41a7dd42 | 1446 | pr_warn("error on getting new probe.\n"); |
231e36f4 | 1447 | warn++; |
41a7dd42 | 1448 | } else { |
c31ffb3f | 1449 | file = find_trace_probe_file(tk, top_trace_array()); |
41a7dd42 MH |
1450 | if (WARN_ON_ONCE(file == NULL)) { |
1451 | pr_warn("error on getting probe file.\n"); | |
1452 | warn++; | |
1453 | } else | |
c31ffb3f | 1454 | enable_trace_kprobe(tk, file); |
41a7dd42 | 1455 | } |
231e36f4 | 1456 | } |
413d37d1 | 1457 | |
7e465baa TZ |
1458 | ret = trace_run_command("r:testprobe2 kprobe_trace_selftest_target " |
1459 | "$retval", create_trace_kprobe); | |
231e36f4 | 1460 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1461 | pr_warn("error on probing function return.\n"); |
231e36f4 MH |
1462 | warn++; |
1463 | } else { | |
1464 | /* Enable trace point */ | |
c31ffb3f NK |
1465 | tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM); |
1466 | if (WARN_ON_ONCE(tk == NULL)) { | |
41a7dd42 | 1467 | pr_warn("error on getting 2nd new probe.\n"); |
231e36f4 | 1468 | warn++; |
41a7dd42 | 1469 | } else { |
c31ffb3f | 1470 | file = find_trace_probe_file(tk, top_trace_array()); |
41a7dd42 MH |
1471 | if (WARN_ON_ONCE(file == NULL)) { |
1472 | pr_warn("error on getting probe file.\n"); | |
1473 | warn++; | |
1474 | } else | |
c31ffb3f | 1475 | enable_trace_kprobe(tk, file); |
41a7dd42 | 1476 | } |
231e36f4 MH |
1477 | } |
1478 | ||
1479 | if (warn) | |
1480 | goto end; | |
413d37d1 MH |
1481 | |
1482 | ret = target(1, 2, 3, 4, 5, 6); | |
1483 | ||
d4d7ccc8 MN |
1484 | /* |
1485 | * Not expecting an error here, the check is only to prevent the | |
1486 | * optimizer from removing the call to target() as otherwise there | |
1487 | * are no side-effects and the call is never performed. | |
1488 | */ | |
1489 | if (ret != 21) | |
1490 | warn++; | |
1491 | ||
02ca1521 | 1492 | /* Disable trace points before removing it */ |
c31ffb3f NK |
1493 | tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM); |
1494 | if (WARN_ON_ONCE(tk == NULL)) { | |
41a7dd42 | 1495 | pr_warn("error on getting test probe.\n"); |
02ca1521 | 1496 | warn++; |
41a7dd42 | 1497 | } else { |
d4d7ccc8 MN |
1498 | if (trace_kprobe_nhit(tk) != 1) { |
1499 | pr_warn("incorrect number of testprobe hits\n"); | |
1500 | warn++; | |
1501 | } | |
1502 | ||
c31ffb3f | 1503 | file = find_trace_probe_file(tk, top_trace_array()); |
41a7dd42 MH |
1504 | if (WARN_ON_ONCE(file == NULL)) { |
1505 | pr_warn("error on getting probe file.\n"); | |
1506 | warn++; | |
1507 | } else | |
c31ffb3f | 1508 | disable_trace_kprobe(tk, file); |
41a7dd42 | 1509 | } |
02ca1521 | 1510 | |
c31ffb3f NK |
1511 | tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM); |
1512 | if (WARN_ON_ONCE(tk == NULL)) { | |
41a7dd42 | 1513 | pr_warn("error on getting 2nd test probe.\n"); |
02ca1521 | 1514 | warn++; |
41a7dd42 | 1515 | } else { |
d4d7ccc8 MN |
1516 | if (trace_kprobe_nhit(tk) != 1) { |
1517 | pr_warn("incorrect number of testprobe2 hits\n"); | |
1518 | warn++; | |
1519 | } | |
1520 | ||
c31ffb3f | 1521 | file = find_trace_probe_file(tk, top_trace_array()); |
41a7dd42 MH |
1522 | if (WARN_ON_ONCE(file == NULL)) { |
1523 | pr_warn("error on getting probe file.\n"); | |
1524 | warn++; | |
1525 | } else | |
c31ffb3f | 1526 | disable_trace_kprobe(tk, file); |
41a7dd42 | 1527 | } |
02ca1521 | 1528 | |
7e465baa | 1529 | ret = trace_run_command("-:testprobe", create_trace_kprobe); |
231e36f4 | 1530 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1531 | pr_warn("error on deleting a probe.\n"); |
231e36f4 MH |
1532 | warn++; |
1533 | } | |
1534 | ||
7e465baa | 1535 | ret = trace_run_command("-:testprobe2", create_trace_kprobe); |
231e36f4 | 1536 | if (WARN_ON_ONCE(ret)) { |
41a7dd42 | 1537 | pr_warn("error on deleting a probe.\n"); |
231e36f4 MH |
1538 | warn++; |
1539 | } | |
413d37d1 | 1540 | |
231e36f4 | 1541 | end: |
c31ffb3f | 1542 | release_all_trace_kprobes(); |
30e7d894 TG |
1543 | /* |
1544 | * Wait for the optimizer work to finish. Otherwise it might fiddle | |
1545 | * with probes in already freed __init text. | |
1546 | */ | |
1547 | wait_for_kprobe_optimizer(); | |
231e36f4 MH |
1548 | if (warn) |
1549 | pr_cont("NG: Some tests are failed. Please check them.\n"); | |
1550 | else | |
1551 | pr_cont("OK\n"); | |
413d37d1 MH |
1552 | return 0; |
1553 | } | |
1554 | ||
1555 | late_initcall(kprobe_trace_self_tests_init); | |
1556 | ||
1557 | #endif |