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Commit | Line | Data |
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bcea3f96 | 1 | // SPDX-License-Identifier: GPL-2.0 |
f3f096cf SD |
2 | /* |
3 | * uprobes-based tracing events | |
4 | * | |
f3f096cf SD |
5 | * Copyright (C) IBM Corporation, 2010-2012 |
6 | * Author: Srikar Dronamraju <srikar@linux.vnet.ibm.com> | |
7 | */ | |
72576341 | 8 | #define pr_fmt(fmt) "trace_kprobe: " fmt |
f3f096cf SD |
9 | |
10 | #include <linux/module.h> | |
11 | #include <linux/uaccess.h> | |
12 | #include <linux/uprobes.h> | |
13 | #include <linux/namei.h> | |
b2e902f0 | 14 | #include <linux/string.h> |
b2d09103 | 15 | #include <linux/rculist.h> |
f3f096cf SD |
16 | |
17 | #include "trace_probe.h" | |
53305928 | 18 | #include "trace_probe_tmpl.h" |
f3f096cf SD |
19 | |
20 | #define UPROBE_EVENT_SYSTEM "uprobes" | |
21 | ||
457d1772 ON |
22 | struct uprobe_trace_entry_head { |
23 | struct trace_entry ent; | |
24 | unsigned long vaddr[]; | |
25 | }; | |
26 | ||
27 | #define SIZEOF_TRACE_ENTRY(is_return) \ | |
28 | (sizeof(struct uprobe_trace_entry_head) + \ | |
29 | sizeof(unsigned long) * (is_return ? 2 : 1)) | |
30 | ||
31 | #define DATAOF_TRACE_ENTRY(entry, is_return) \ | |
32 | ((void*)(entry) + SIZEOF_TRACE_ENTRY(is_return)) | |
33 | ||
736288ba ON |
34 | struct trace_uprobe_filter { |
35 | rwlock_t rwlock; | |
36 | int nr_systemwide; | |
37 | struct list_head perf_events; | |
38 | }; | |
39 | ||
f3f096cf SD |
40 | /* |
41 | * uprobe event core functions | |
42 | */ | |
f3f096cf SD |
43 | struct trace_uprobe { |
44 | struct list_head list; | |
736288ba | 45 | struct trace_uprobe_filter filter; |
a932b738 | 46 | struct uprobe_consumer consumer; |
0c92c7a3 | 47 | struct path path; |
f3f096cf SD |
48 | struct inode *inode; |
49 | char *filename; | |
50 | unsigned long offset; | |
1cc33161 | 51 | unsigned long ref_ctr_offset; |
f3f096cf | 52 | unsigned long nhit; |
14577c39 | 53 | struct trace_probe tp; |
f3f096cf SD |
54 | }; |
55 | ||
14577c39 NK |
56 | #define SIZEOF_TRACE_UPROBE(n) \ |
57 | (offsetof(struct trace_uprobe, tp.args) + \ | |
f3f096cf SD |
58 | (sizeof(struct probe_arg) * (n))) |
59 | ||
60 | static int register_uprobe_event(struct trace_uprobe *tu); | |
c6c2401d | 61 | static int unregister_uprobe_event(struct trace_uprobe *tu); |
f3f096cf SD |
62 | |
63 | static DEFINE_MUTEX(uprobe_lock); | |
64 | static LIST_HEAD(uprobe_list); | |
65 | ||
b7e0bf34 NK |
66 | struct uprobe_dispatch_data { |
67 | struct trace_uprobe *tu; | |
68 | unsigned long bp_addr; | |
69 | }; | |
70 | ||
f3f096cf | 71 | static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs); |
c1ae5c75 ON |
72 | static int uretprobe_dispatcher(struct uprobe_consumer *con, |
73 | unsigned long func, struct pt_regs *regs); | |
f3f096cf | 74 | |
3fd996a2 NK |
75 | #ifdef CONFIG_STACK_GROWSUP |
76 | static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n) | |
77 | { | |
78 | return addr - (n * sizeof(long)); | |
79 | } | |
80 | #else | |
81 | static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n) | |
82 | { | |
83 | return addr + (n * sizeof(long)); | |
84 | } | |
85 | #endif | |
86 | ||
87 | static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n) | |
88 | { | |
89 | unsigned long ret; | |
90 | unsigned long addr = user_stack_pointer(regs); | |
91 | ||
92 | addr = adjust_stack_addr(addr, n); | |
93 | ||
94 | if (copy_from_user(&ret, (void __force __user *) addr, sizeof(ret))) | |
95 | return 0; | |
96 | ||
97 | return ret; | |
98 | } | |
99 | ||
100 | /* | |
101 | * Uprobes-specific fetch functions | |
102 | */ | |
53305928 MH |
103 | static nokprobe_inline int |
104 | probe_user_read(void *dest, void *src, size_t size) | |
105 | { | |
106 | void __user *vaddr = (void __force __user *)src; | |
107 | ||
108 | return copy_from_user(dest, vaddr, size); | |
5baaa59e | 109 | } |
5baaa59e NK |
110 | /* |
111 | * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max | |
112 | * length and relative data location. | |
113 | */ | |
53305928 MH |
114 | static nokprobe_inline void |
115 | fetch_store_string(unsigned long addr, void *dest) | |
5baaa59e NK |
116 | { |
117 | long ret; | |
118 | u32 rloc = *(u32 *)dest; | |
119 | int maxlen = get_rloc_len(rloc); | |
120 | u8 *dst = get_rloc_data(dest); | |
121 | void __user *src = (void __force __user *) addr; | |
122 | ||
123 | if (!maxlen) | |
124 | return; | |
125 | ||
126 | ret = strncpy_from_user(dst, src, maxlen); | |
50268a3d MH |
127 | if (ret == maxlen) |
128 | dst[--ret] = '\0'; | |
5baaa59e NK |
129 | |
130 | if (ret < 0) { /* Failed to fetch string */ | |
131 | ((u8 *)get_rloc_data(dest))[0] = '\0'; | |
132 | *(u32 *)dest = make_data_rloc(0, get_rloc_offs(rloc)); | |
133 | } else { | |
134 | *(u32 *)dest = make_data_rloc(ret, get_rloc_offs(rloc)); | |
135 | } | |
136 | } | |
137 | ||
53305928 MH |
138 | /* Return the length of string -- including null terminal byte */ |
139 | static nokprobe_inline void | |
140 | fetch_store_strlen(unsigned long addr, void *dest) | |
5baaa59e NK |
141 | { |
142 | int len; | |
143 | void __user *vaddr = (void __force __user *) addr; | |
144 | ||
145 | len = strnlen_user(vaddr, MAX_STRING_SIZE); | |
146 | ||
147 | if (len == 0 || len > MAX_STRING_SIZE) /* Failed to check length */ | |
148 | *(u32 *)dest = 0; | |
149 | else | |
150 | *(u32 *)dest = len; | |
151 | } | |
3fd996a2 | 152 | |
53305928 | 153 | static unsigned long translate_user_vaddr(unsigned long file_offset) |
b7e0bf34 NK |
154 | { |
155 | unsigned long base_addr; | |
156 | struct uprobe_dispatch_data *udd; | |
157 | ||
158 | udd = (void *) current->utask->vaddr; | |
159 | ||
160 | base_addr = udd->bp_addr - udd->tu->offset; | |
53305928 | 161 | return base_addr + file_offset; |
b7e0bf34 | 162 | } |
b7e0bf34 | 163 | |
53305928 MH |
164 | /* Note that we don't verify it, since the code does not come from user space */ |
165 | static int | |
166 | process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest, | |
167 | bool pre) | |
168 | { | |
169 | unsigned long val; | |
170 | int ret; | |
171 | ||
172 | /* 1st stage: get value from context */ | |
173 | switch (code->op) { | |
174 | case FETCH_OP_REG: | |
175 | val = regs_get_register(regs, code->param); | |
176 | break; | |
177 | case FETCH_OP_STACK: | |
178 | val = get_user_stack_nth(regs, code->param); | |
179 | break; | |
180 | case FETCH_OP_STACKP: | |
181 | val = user_stack_pointer(regs); | |
182 | break; | |
183 | case FETCH_OP_RETVAL: | |
184 | val = regs_return_value(regs); | |
185 | break; | |
186 | case FETCH_OP_IMM: | |
187 | val = code->immediate; | |
188 | break; | |
189 | case FETCH_OP_FOFFS: | |
190 | val = translate_user_vaddr(code->immediate); | |
191 | break; | |
192 | default: | |
193 | return -EILSEQ; | |
194 | } | |
195 | code++; | |
196 | ||
197 | /* 2nd stage: dereference memory if needed */ | |
198 | while (code->op == FETCH_OP_DEREF) { | |
199 | ret = probe_user_read(&val, (void *)val + code->offset, | |
200 | sizeof(val)); | |
201 | if (ret) | |
202 | return ret; | |
203 | code++; | |
204 | } | |
205 | ||
206 | /* 3rd stage: store value to buffer */ | |
207 | switch (code->op) { | |
208 | case FETCH_OP_ST_RAW: | |
209 | fetch_store_raw(val, code, dest); | |
210 | break; | |
211 | case FETCH_OP_ST_MEM: | |
212 | probe_user_read(dest, (void *)val + code->offset, code->size); | |
213 | break; | |
214 | case FETCH_OP_ST_STRING: | |
215 | if (pre) | |
216 | fetch_store_strlen(val + code->offset, dest); | |
217 | else | |
218 | fetch_store_string(val + code->offset, dest); | |
219 | break; | |
220 | default: | |
221 | return -EILSEQ; | |
222 | } | |
223 | code++; | |
224 | ||
225 | /* 4th stage: modify stored value if needed */ | |
226 | if (code->op == FETCH_OP_MOD_BF) { | |
227 | fetch_apply_bitfield(code, dest); | |
228 | code++; | |
229 | } | |
230 | ||
231 | return code->op == FETCH_OP_END ? 0 : -EILSEQ; | |
232 | } | |
233 | NOKPROBE_SYMBOL(process_fetch_insn) | |
234 | ||
736288ba ON |
235 | static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter) |
236 | { | |
237 | rwlock_init(&filter->rwlock); | |
238 | filter->nr_systemwide = 0; | |
239 | INIT_LIST_HEAD(&filter->perf_events); | |
240 | } | |
241 | ||
242 | static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter) | |
243 | { | |
244 | return !filter->nr_systemwide && list_empty(&filter->perf_events); | |
245 | } | |
246 | ||
c1ae5c75 ON |
247 | static inline bool is_ret_probe(struct trace_uprobe *tu) |
248 | { | |
249 | return tu->consumer.ret_handler != NULL; | |
250 | } | |
251 | ||
f3f096cf SD |
252 | /* |
253 | * Allocate new trace_uprobe and initialize it (including uprobes). | |
254 | */ | |
255 | static struct trace_uprobe * | |
c1ae5c75 | 256 | alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret) |
f3f096cf SD |
257 | { |
258 | struct trace_uprobe *tu; | |
259 | ||
260 | if (!event || !is_good_name(event)) | |
261 | return ERR_PTR(-EINVAL); | |
262 | ||
263 | if (!group || !is_good_name(group)) | |
264 | return ERR_PTR(-EINVAL); | |
265 | ||
266 | tu = kzalloc(SIZEOF_TRACE_UPROBE(nargs), GFP_KERNEL); | |
267 | if (!tu) | |
268 | return ERR_PTR(-ENOMEM); | |
269 | ||
14577c39 NK |
270 | tu->tp.call.class = &tu->tp.class; |
271 | tu->tp.call.name = kstrdup(event, GFP_KERNEL); | |
272 | if (!tu->tp.call.name) | |
f3f096cf SD |
273 | goto error; |
274 | ||
14577c39 NK |
275 | tu->tp.class.system = kstrdup(group, GFP_KERNEL); |
276 | if (!tu->tp.class.system) | |
f3f096cf SD |
277 | goto error; |
278 | ||
279 | INIT_LIST_HEAD(&tu->list); | |
70ed91c6 | 280 | INIT_LIST_HEAD(&tu->tp.files); |
a932b738 | 281 | tu->consumer.handler = uprobe_dispatcher; |
c1ae5c75 ON |
282 | if (is_ret) |
283 | tu->consumer.ret_handler = uretprobe_dispatcher; | |
736288ba | 284 | init_trace_uprobe_filter(&tu->filter); |
f3f096cf SD |
285 | return tu; |
286 | ||
287 | error: | |
14577c39 | 288 | kfree(tu->tp.call.name); |
f3f096cf SD |
289 | kfree(tu); |
290 | ||
291 | return ERR_PTR(-ENOMEM); | |
292 | } | |
293 | ||
294 | static void free_trace_uprobe(struct trace_uprobe *tu) | |
295 | { | |
296 | int i; | |
297 | ||
14577c39 NK |
298 | for (i = 0; i < tu->tp.nr_args; i++) |
299 | traceprobe_free_probe_arg(&tu->tp.args[i]); | |
f3f096cf | 300 | |
0c92c7a3 | 301 | path_put(&tu->path); |
14577c39 NK |
302 | kfree(tu->tp.call.class->system); |
303 | kfree(tu->tp.call.name); | |
f3f096cf SD |
304 | kfree(tu->filename); |
305 | kfree(tu); | |
306 | } | |
307 | ||
308 | static struct trace_uprobe *find_probe_event(const char *event, const char *group) | |
309 | { | |
310 | struct trace_uprobe *tu; | |
311 | ||
312 | list_for_each_entry(tu, &uprobe_list, list) | |
687fcc4a | 313 | if (strcmp(trace_event_name(&tu->tp.call), event) == 0 && |
14577c39 | 314 | strcmp(tu->tp.call.class->system, group) == 0) |
f3f096cf SD |
315 | return tu; |
316 | ||
317 | return NULL; | |
318 | } | |
319 | ||
320 | /* Unregister a trace_uprobe and probe_event: call with locking uprobe_lock */ | |
c6c2401d | 321 | static int unregister_trace_uprobe(struct trace_uprobe *tu) |
f3f096cf | 322 | { |
c6c2401d SRRH |
323 | int ret; |
324 | ||
325 | ret = unregister_uprobe_event(tu); | |
326 | if (ret) | |
327 | return ret; | |
328 | ||
f3f096cf | 329 | list_del(&tu->list); |
f3f096cf | 330 | free_trace_uprobe(tu); |
c6c2401d | 331 | return 0; |
f3f096cf SD |
332 | } |
333 | ||
ccea8727 RB |
334 | /* |
335 | * Uprobe with multiple reference counter is not allowed. i.e. | |
336 | * If inode and offset matches, reference counter offset *must* | |
337 | * match as well. Though, there is one exception: If user is | |
338 | * replacing old trace_uprobe with new one(same group/event), | |
339 | * then we allow same uprobe with new reference counter as far | |
340 | * as the new one does not conflict with any other existing | |
341 | * ones. | |
342 | */ | |
343 | static struct trace_uprobe *find_old_trace_uprobe(struct trace_uprobe *new) | |
344 | { | |
345 | struct trace_uprobe *tmp, *old = NULL; | |
346 | struct inode *new_inode = d_real_inode(new->path.dentry); | |
347 | ||
348 | old = find_probe_event(trace_event_name(&new->tp.call), | |
349 | new->tp.call.class->system); | |
350 | ||
351 | list_for_each_entry(tmp, &uprobe_list, list) { | |
352 | if ((old ? old != tmp : true) && | |
353 | new_inode == d_real_inode(tmp->path.dentry) && | |
354 | new->offset == tmp->offset && | |
355 | new->ref_ctr_offset != tmp->ref_ctr_offset) { | |
356 | pr_warn("Reference counter offset mismatch."); | |
357 | return ERR_PTR(-EINVAL); | |
358 | } | |
359 | } | |
360 | return old; | |
361 | } | |
362 | ||
f3f096cf SD |
363 | /* Register a trace_uprobe and probe_event */ |
364 | static int register_trace_uprobe(struct trace_uprobe *tu) | |
365 | { | |
14577c39 | 366 | struct trace_uprobe *old_tu; |
f3f096cf SD |
367 | int ret; |
368 | ||
369 | mutex_lock(&uprobe_lock); | |
370 | ||
371 | /* register as an event */ | |
ccea8727 RB |
372 | old_tu = find_old_trace_uprobe(tu); |
373 | if (IS_ERR(old_tu)) { | |
374 | ret = PTR_ERR(old_tu); | |
375 | goto end; | |
376 | } | |
377 | ||
14577c39 | 378 | if (old_tu) { |
f3f096cf | 379 | /* delete old event */ |
14577c39 | 380 | ret = unregister_trace_uprobe(old_tu); |
c6c2401d SRRH |
381 | if (ret) |
382 | goto end; | |
383 | } | |
f3f096cf SD |
384 | |
385 | ret = register_uprobe_event(tu); | |
386 | if (ret) { | |
a395d6a7 | 387 | pr_warn("Failed to register probe event(%d)\n", ret); |
f3f096cf SD |
388 | goto end; |
389 | } | |
390 | ||
391 | list_add_tail(&tu->list, &uprobe_list); | |
392 | ||
393 | end: | |
394 | mutex_unlock(&uprobe_lock); | |
395 | ||
396 | return ret; | |
397 | } | |
398 | ||
399 | /* | |
400 | * Argument syntax: | |
306cfe20 | 401 | * - Add uprobe: p|r[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS] |
f3f096cf SD |
402 | * |
403 | * - Remove uprobe: -:[GRP/]EVENT | |
404 | */ | |
405 | static int create_trace_uprobe(int argc, char **argv) | |
406 | { | |
407 | struct trace_uprobe *tu; | |
1cc33161 | 408 | char *arg, *event, *group, *filename, *rctr, *rctr_end; |
f3f096cf SD |
409 | char buf[MAX_EVENT_NAME_LEN]; |
410 | struct path path; | |
1cc33161 | 411 | unsigned long offset, ref_ctr_offset; |
4ee5a52e | 412 | bool is_delete, is_return; |
f3f096cf SD |
413 | int i, ret; |
414 | ||
f3f096cf SD |
415 | ret = 0; |
416 | is_delete = false; | |
4ee5a52e | 417 | is_return = false; |
f3f096cf SD |
418 | event = NULL; |
419 | group = NULL; | |
1cc33161 | 420 | ref_ctr_offset = 0; |
f3f096cf SD |
421 | |
422 | /* argc must be >= 1 */ | |
423 | if (argv[0][0] == '-') | |
424 | is_delete = true; | |
4ee5a52e ON |
425 | else if (argv[0][0] == 'r') |
426 | is_return = true; | |
f3f096cf | 427 | else if (argv[0][0] != 'p') { |
4ee5a52e | 428 | pr_info("Probe definition must be started with 'p', 'r' or '-'.\n"); |
f3f096cf SD |
429 | return -EINVAL; |
430 | } | |
431 | ||
432 | if (argv[0][1] == ':') { | |
433 | event = &argv[0][2]; | |
434 | arg = strchr(event, '/'); | |
435 | ||
436 | if (arg) { | |
437 | group = event; | |
438 | event = arg + 1; | |
439 | event[-1] = '\0'; | |
440 | ||
441 | if (strlen(group) == 0) { | |
442 | pr_info("Group name is not specified\n"); | |
443 | return -EINVAL; | |
444 | } | |
445 | } | |
446 | if (strlen(event) == 0) { | |
447 | pr_info("Event name is not specified\n"); | |
448 | return -EINVAL; | |
449 | } | |
450 | } | |
451 | if (!group) | |
452 | group = UPROBE_EVENT_SYSTEM; | |
453 | ||
454 | if (is_delete) { | |
c6c2401d SRRH |
455 | int ret; |
456 | ||
f3f096cf SD |
457 | if (!event) { |
458 | pr_info("Delete command needs an event name.\n"); | |
459 | return -EINVAL; | |
460 | } | |
461 | mutex_lock(&uprobe_lock); | |
462 | tu = find_probe_event(event, group); | |
463 | ||
464 | if (!tu) { | |
465 | mutex_unlock(&uprobe_lock); | |
466 | pr_info("Event %s/%s doesn't exist.\n", group, event); | |
467 | return -ENOENT; | |
468 | } | |
469 | /* delete an event */ | |
c6c2401d | 470 | ret = unregister_trace_uprobe(tu); |
f3f096cf | 471 | mutex_unlock(&uprobe_lock); |
c6c2401d | 472 | return ret; |
f3f096cf SD |
473 | } |
474 | ||
475 | if (argc < 2) { | |
476 | pr_info("Probe point is not specified.\n"); | |
477 | return -EINVAL; | |
478 | } | |
6496bb72 KY |
479 | /* Find the last occurrence, in case the path contains ':' too. */ |
480 | arg = strrchr(argv[1], ':'); | |
0c92c7a3 SL |
481 | if (!arg) |
482 | return -EINVAL; | |
f3f096cf SD |
483 | |
484 | *arg++ = '\0'; | |
485 | filename = argv[1]; | |
486 | ret = kern_path(filename, LOOKUP_FOLLOW, &path); | |
487 | if (ret) | |
0c92c7a3 | 488 | return ret; |
84d7ed79 | 489 | |
0c92c7a3 | 490 | if (!d_is_reg(path.dentry)) { |
d24d7dbf JZ |
491 | ret = -EINVAL; |
492 | goto fail_address_parse; | |
493 | } | |
f3f096cf | 494 | |
1cc33161 RB |
495 | /* Parse reference counter offset if specified. */ |
496 | rctr = strchr(arg, '('); | |
497 | if (rctr) { | |
498 | rctr_end = strchr(rctr, ')'); | |
499 | if (rctr > rctr_end || *(rctr_end + 1) != 0) { | |
500 | ret = -EINVAL; | |
501 | pr_info("Invalid reference counter offset.\n"); | |
502 | goto fail_address_parse; | |
503 | } | |
504 | ||
505 | *rctr++ = '\0'; | |
506 | *rctr_end = '\0'; | |
507 | ret = kstrtoul(rctr, 0, &ref_ctr_offset); | |
508 | if (ret) { | |
509 | pr_info("Invalid reference counter offset.\n"); | |
510 | goto fail_address_parse; | |
511 | } | |
512 | } | |
513 | ||
514 | /* Parse uprobe offset. */ | |
84d7ed79 ON |
515 | ret = kstrtoul(arg, 0, &offset); |
516 | if (ret) | |
517 | goto fail_address_parse; | |
518 | ||
f3f096cf SD |
519 | argc -= 2; |
520 | argv += 2; | |
521 | ||
522 | /* setup a probe */ | |
523 | if (!event) { | |
b2e902f0 | 524 | char *tail; |
f3f096cf SD |
525 | char *ptr; |
526 | ||
b2e902f0 AS |
527 | tail = kstrdup(kbasename(filename), GFP_KERNEL); |
528 | if (!tail) { | |
f3f096cf SD |
529 | ret = -ENOMEM; |
530 | goto fail_address_parse; | |
531 | } | |
532 | ||
f3f096cf SD |
533 | ptr = strpbrk(tail, ".-_"); |
534 | if (ptr) | |
535 | *ptr = '\0'; | |
536 | ||
537 | snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset); | |
538 | event = buf; | |
539 | kfree(tail); | |
540 | } | |
541 | ||
4ee5a52e | 542 | tu = alloc_trace_uprobe(group, event, argc, is_return); |
f3f096cf SD |
543 | if (IS_ERR(tu)) { |
544 | pr_info("Failed to allocate trace_uprobe.(%d)\n", (int)PTR_ERR(tu)); | |
545 | ret = PTR_ERR(tu); | |
546 | goto fail_address_parse; | |
547 | } | |
548 | tu->offset = offset; | |
1cc33161 | 549 | tu->ref_ctr_offset = ref_ctr_offset; |
0c92c7a3 | 550 | tu->path = path; |
f3f096cf SD |
551 | tu->filename = kstrdup(filename, GFP_KERNEL); |
552 | ||
553 | if (!tu->filename) { | |
554 | pr_info("Failed to allocate filename.\n"); | |
555 | ret = -ENOMEM; | |
556 | goto error; | |
557 | } | |
558 | ||
559 | /* parse arguments */ | |
560 | ret = 0; | |
561 | for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { | |
14577c39 NK |
562 | struct probe_arg *parg = &tu->tp.args[i]; |
563 | ||
f3f096cf | 564 | /* Increment count for freeing args in error case */ |
14577c39 | 565 | tu->tp.nr_args++; |
f3f096cf SD |
566 | |
567 | /* Parse argument name */ | |
568 | arg = strchr(argv[i], '='); | |
569 | if (arg) { | |
570 | *arg++ = '\0'; | |
14577c39 | 571 | parg->name = kstrdup(argv[i], GFP_KERNEL); |
f3f096cf SD |
572 | } else { |
573 | arg = argv[i]; | |
574 | /* If argument name is omitted, set "argN" */ | |
575 | snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1); | |
14577c39 | 576 | parg->name = kstrdup(buf, GFP_KERNEL); |
f3f096cf SD |
577 | } |
578 | ||
14577c39 | 579 | if (!parg->name) { |
f3f096cf SD |
580 | pr_info("Failed to allocate argument[%d] name.\n", i); |
581 | ret = -ENOMEM; | |
582 | goto error; | |
583 | } | |
584 | ||
14577c39 NK |
585 | if (!is_good_name(parg->name)) { |
586 | pr_info("Invalid argument[%d] name: %s\n", i, parg->name); | |
f3f096cf SD |
587 | ret = -EINVAL; |
588 | goto error; | |
589 | } | |
590 | ||
14577c39 | 591 | if (traceprobe_conflict_field_name(parg->name, tu->tp.args, i)) { |
f3f096cf SD |
592 | pr_info("Argument[%d] name '%s' conflicts with " |
593 | "another field.\n", i, argv[i]); | |
594 | ret = -EINVAL; | |
595 | goto error; | |
596 | } | |
597 | ||
598 | /* Parse fetch argument */ | |
14577c39 | 599 | ret = traceprobe_parse_probe_arg(arg, &tu->tp.size, parg, |
f451bc89 | 600 | is_return, false); |
f3f096cf SD |
601 | if (ret) { |
602 | pr_info("Parse error at argument[%d]. (%d)\n", i, ret); | |
603 | goto error; | |
604 | } | |
605 | } | |
606 | ||
607 | ret = register_trace_uprobe(tu); | |
608 | if (ret) | |
609 | goto error; | |
610 | return 0; | |
611 | ||
612 | error: | |
613 | free_trace_uprobe(tu); | |
614 | return ret; | |
615 | ||
616 | fail_address_parse: | |
0c92c7a3 | 617 | path_put(&path); |
f3f096cf | 618 | |
d24d7dbf | 619 | pr_info("Failed to parse address or file.\n"); |
f3f096cf SD |
620 | |
621 | return ret; | |
622 | } | |
623 | ||
c6c2401d | 624 | static int cleanup_all_probes(void) |
f3f096cf SD |
625 | { |
626 | struct trace_uprobe *tu; | |
c6c2401d | 627 | int ret = 0; |
f3f096cf SD |
628 | |
629 | mutex_lock(&uprobe_lock); | |
630 | while (!list_empty(&uprobe_list)) { | |
631 | tu = list_entry(uprobe_list.next, struct trace_uprobe, list); | |
c6c2401d SRRH |
632 | ret = unregister_trace_uprobe(tu); |
633 | if (ret) | |
634 | break; | |
f3f096cf SD |
635 | } |
636 | mutex_unlock(&uprobe_lock); | |
c6c2401d | 637 | return ret; |
f3f096cf SD |
638 | } |
639 | ||
640 | /* Probes listing interfaces */ | |
641 | static void *probes_seq_start(struct seq_file *m, loff_t *pos) | |
642 | { | |
643 | mutex_lock(&uprobe_lock); | |
644 | return seq_list_start(&uprobe_list, *pos); | |
645 | } | |
646 | ||
647 | static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos) | |
648 | { | |
649 | return seq_list_next(v, &uprobe_list, pos); | |
650 | } | |
651 | ||
652 | static void probes_seq_stop(struct seq_file *m, void *v) | |
653 | { | |
654 | mutex_unlock(&uprobe_lock); | |
655 | } | |
656 | ||
657 | static int probes_seq_show(struct seq_file *m, void *v) | |
658 | { | |
659 | struct trace_uprobe *tu = v; | |
3ede82dd | 660 | char c = is_ret_probe(tu) ? 'r' : 'p'; |
f3f096cf SD |
661 | int i; |
662 | ||
a64b2c01 RB |
663 | seq_printf(m, "%c:%s/%s %s:0x%0*lx", c, tu->tp.call.class->system, |
664 | trace_event_name(&tu->tp.call), tu->filename, | |
665 | (int)(sizeof(void *) * 2), tu->offset); | |
f3f096cf | 666 | |
1cc33161 RB |
667 | if (tu->ref_ctr_offset) |
668 | seq_printf(m, "(0x%lx)", tu->ref_ctr_offset); | |
669 | ||
14577c39 NK |
670 | for (i = 0; i < tu->tp.nr_args; i++) |
671 | seq_printf(m, " %s=%s", tu->tp.args[i].name, tu->tp.args[i].comm); | |
f3f096cf | 672 | |
fa6f0cc7 | 673 | seq_putc(m, '\n'); |
f3f096cf SD |
674 | return 0; |
675 | } | |
676 | ||
677 | static const struct seq_operations probes_seq_op = { | |
678 | .start = probes_seq_start, | |
679 | .next = probes_seq_next, | |
680 | .stop = probes_seq_stop, | |
681 | .show = probes_seq_show | |
682 | }; | |
683 | ||
684 | static int probes_open(struct inode *inode, struct file *file) | |
685 | { | |
c6c2401d SRRH |
686 | int ret; |
687 | ||
688 | if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { | |
689 | ret = cleanup_all_probes(); | |
690 | if (ret) | |
691 | return ret; | |
692 | } | |
f3f096cf SD |
693 | |
694 | return seq_open(file, &probes_seq_op); | |
695 | } | |
696 | ||
697 | static ssize_t probes_write(struct file *file, const char __user *buffer, | |
698 | size_t count, loff_t *ppos) | |
699 | { | |
7e465baa | 700 | return trace_parse_run_command(file, buffer, count, ppos, create_trace_uprobe); |
f3f096cf SD |
701 | } |
702 | ||
703 | static const struct file_operations uprobe_events_ops = { | |
704 | .owner = THIS_MODULE, | |
705 | .open = probes_open, | |
706 | .read = seq_read, | |
707 | .llseek = seq_lseek, | |
708 | .release = seq_release, | |
709 | .write = probes_write, | |
710 | }; | |
711 | ||
712 | /* Probes profiling interfaces */ | |
713 | static int probes_profile_seq_show(struct seq_file *m, void *v) | |
714 | { | |
715 | struct trace_uprobe *tu = v; | |
716 | ||
de7b2973 | 717 | seq_printf(m, " %s %-44s %15lu\n", tu->filename, |
687fcc4a | 718 | trace_event_name(&tu->tp.call), tu->nhit); |
f3f096cf SD |
719 | return 0; |
720 | } | |
721 | ||
722 | static const struct seq_operations profile_seq_op = { | |
723 | .start = probes_seq_start, | |
724 | .next = probes_seq_next, | |
725 | .stop = probes_seq_stop, | |
726 | .show = probes_profile_seq_show | |
727 | }; | |
728 | ||
729 | static int profile_open(struct inode *inode, struct file *file) | |
730 | { | |
731 | return seq_open(file, &profile_seq_op); | |
732 | } | |
733 | ||
734 | static const struct file_operations uprobe_profile_ops = { | |
735 | .owner = THIS_MODULE, | |
736 | .open = profile_open, | |
737 | .read = seq_read, | |
738 | .llseek = seq_lseek, | |
739 | .release = seq_release, | |
740 | }; | |
741 | ||
dcad1a20 NK |
742 | struct uprobe_cpu_buffer { |
743 | struct mutex mutex; | |
744 | void *buf; | |
745 | }; | |
746 | static struct uprobe_cpu_buffer __percpu *uprobe_cpu_buffer; | |
747 | static int uprobe_buffer_refcnt; | |
748 | ||
749 | static int uprobe_buffer_init(void) | |
750 | { | |
751 | int cpu, err_cpu; | |
752 | ||
753 | uprobe_cpu_buffer = alloc_percpu(struct uprobe_cpu_buffer); | |
754 | if (uprobe_cpu_buffer == NULL) | |
755 | return -ENOMEM; | |
756 | ||
757 | for_each_possible_cpu(cpu) { | |
758 | struct page *p = alloc_pages_node(cpu_to_node(cpu), | |
759 | GFP_KERNEL, 0); | |
760 | if (p == NULL) { | |
761 | err_cpu = cpu; | |
762 | goto err; | |
763 | } | |
764 | per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf = page_address(p); | |
765 | mutex_init(&per_cpu_ptr(uprobe_cpu_buffer, cpu)->mutex); | |
766 | } | |
767 | ||
768 | return 0; | |
769 | ||
770 | err: | |
771 | for_each_possible_cpu(cpu) { | |
772 | if (cpu == err_cpu) | |
773 | break; | |
774 | free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf); | |
775 | } | |
776 | ||
777 | free_percpu(uprobe_cpu_buffer); | |
778 | return -ENOMEM; | |
779 | } | |
780 | ||
781 | static int uprobe_buffer_enable(void) | |
782 | { | |
783 | int ret = 0; | |
784 | ||
785 | BUG_ON(!mutex_is_locked(&event_mutex)); | |
786 | ||
787 | if (uprobe_buffer_refcnt++ == 0) { | |
788 | ret = uprobe_buffer_init(); | |
789 | if (ret < 0) | |
790 | uprobe_buffer_refcnt--; | |
791 | } | |
792 | ||
793 | return ret; | |
794 | } | |
795 | ||
796 | static void uprobe_buffer_disable(void) | |
797 | { | |
6ea6215f J |
798 | int cpu; |
799 | ||
dcad1a20 NK |
800 | BUG_ON(!mutex_is_locked(&event_mutex)); |
801 | ||
802 | if (--uprobe_buffer_refcnt == 0) { | |
6ea6215f J |
803 | for_each_possible_cpu(cpu) |
804 | free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer, | |
805 | cpu)->buf); | |
806 | ||
dcad1a20 NK |
807 | free_percpu(uprobe_cpu_buffer); |
808 | uprobe_cpu_buffer = NULL; | |
809 | } | |
810 | } | |
811 | ||
812 | static struct uprobe_cpu_buffer *uprobe_buffer_get(void) | |
813 | { | |
814 | struct uprobe_cpu_buffer *ucb; | |
815 | int cpu; | |
816 | ||
817 | cpu = raw_smp_processor_id(); | |
818 | ucb = per_cpu_ptr(uprobe_cpu_buffer, cpu); | |
819 | ||
820 | /* | |
821 | * Use per-cpu buffers for fastest access, but we might migrate | |
822 | * so the mutex makes sure we have sole access to it. | |
823 | */ | |
824 | mutex_lock(&ucb->mutex); | |
825 | ||
826 | return ucb; | |
827 | } | |
828 | ||
829 | static void uprobe_buffer_put(struct uprobe_cpu_buffer *ucb) | |
830 | { | |
831 | mutex_unlock(&ucb->mutex); | |
832 | } | |
833 | ||
a43b9704 | 834 | static void __uprobe_trace_func(struct trace_uprobe *tu, |
dd9fa555 | 835 | unsigned long func, struct pt_regs *regs, |
70ed91c6 | 836 | struct uprobe_cpu_buffer *ucb, int dsize, |
7f1d2f82 | 837 | struct trace_event_file *trace_file) |
f3f096cf SD |
838 | { |
839 | struct uprobe_trace_entry_head *entry; | |
840 | struct ring_buffer_event *event; | |
841 | struct ring_buffer *buffer; | |
457d1772 | 842 | void *data; |
dd9fa555 | 843 | int size, esize; |
2425bcb9 | 844 | struct trace_event_call *call = &tu->tp.call; |
f3f096cf | 845 | |
7f1d2f82 | 846 | WARN_ON(call != trace_file->event_call); |
70ed91c6 | 847 | |
dd9fa555 | 848 | if (WARN_ON_ONCE(tu->tp.size + dsize > PAGE_SIZE)) |
dcad1a20 NK |
849 | return; |
850 | ||
09a5059a | 851 | if (trace_trigger_soft_disabled(trace_file)) |
ca3b1620 NK |
852 | return; |
853 | ||
dd9fa555 | 854 | esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); |
dcad1a20 | 855 | size = esize + tu->tp.size + dsize; |
7f1d2f82 | 856 | event = trace_event_buffer_lock_reserve(&buffer, trace_file, |
70ed91c6 | 857 | call->event.type, size, 0, 0); |
f3f096cf | 858 | if (!event) |
dd9fa555 | 859 | return; |
f3f096cf SD |
860 | |
861 | entry = ring_buffer_event_data(event); | |
393a736c ON |
862 | if (is_ret_probe(tu)) { |
863 | entry->vaddr[0] = func; | |
864 | entry->vaddr[1] = instruction_pointer(regs); | |
865 | data = DATAOF_TRACE_ENTRY(entry, true); | |
866 | } else { | |
867 | entry->vaddr[0] = instruction_pointer(regs); | |
868 | data = DATAOF_TRACE_ENTRY(entry, false); | |
869 | } | |
870 | ||
dcad1a20 | 871 | memcpy(data, ucb->buf, tu->tp.size + dsize); |
f3f096cf | 872 | |
7f1d2f82 | 873 | event_trigger_unlock_commit(trace_file, buffer, event, entry, 0, 0); |
a51cc604 | 874 | } |
f42d24a1 | 875 | |
a51cc604 | 876 | /* uprobe handler */ |
dd9fa555 NK |
877 | static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs, |
878 | struct uprobe_cpu_buffer *ucb, int dsize) | |
a51cc604 | 879 | { |
70ed91c6 J |
880 | struct event_file_link *link; |
881 | ||
882 | if (is_ret_probe(tu)) | |
883 | return 0; | |
884 | ||
885 | rcu_read_lock(); | |
886 | list_for_each_entry_rcu(link, &tu->tp.files, list) | |
887 | __uprobe_trace_func(tu, 0, regs, ucb, dsize, link->file); | |
888 | rcu_read_unlock(); | |
889 | ||
f42d24a1 | 890 | return 0; |
f3f096cf SD |
891 | } |
892 | ||
c1ae5c75 | 893 | static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func, |
dd9fa555 NK |
894 | struct pt_regs *regs, |
895 | struct uprobe_cpu_buffer *ucb, int dsize) | |
c1ae5c75 | 896 | { |
70ed91c6 J |
897 | struct event_file_link *link; |
898 | ||
899 | rcu_read_lock(); | |
900 | list_for_each_entry_rcu(link, &tu->tp.files, list) | |
901 | __uprobe_trace_func(tu, func, regs, ucb, dsize, link->file); | |
902 | rcu_read_unlock(); | |
c1ae5c75 ON |
903 | } |
904 | ||
f3f096cf SD |
905 | /* Event entry printers */ |
906 | static enum print_line_t | |
907 | print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event) | |
908 | { | |
457d1772 | 909 | struct uprobe_trace_entry_head *entry; |
f3f096cf SD |
910 | struct trace_seq *s = &iter->seq; |
911 | struct trace_uprobe *tu; | |
912 | u8 *data; | |
f3f096cf | 913 | |
457d1772 | 914 | entry = (struct uprobe_trace_entry_head *)iter->ent; |
14577c39 | 915 | tu = container_of(event, struct trace_uprobe, tp.call.event); |
f3f096cf | 916 | |
3ede82dd | 917 | if (is_ret_probe(tu)) { |
8579a107 | 918 | trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)", |
687fcc4a | 919 | trace_event_name(&tu->tp.call), |
8579a107 | 920 | entry->vaddr[1], entry->vaddr[0]); |
3ede82dd ON |
921 | data = DATAOF_TRACE_ENTRY(entry, true); |
922 | } else { | |
8579a107 | 923 | trace_seq_printf(s, "%s: (0x%lx)", |
687fcc4a | 924 | trace_event_name(&tu->tp.call), |
8579a107 | 925 | entry->vaddr[0]); |
3ede82dd ON |
926 | data = DATAOF_TRACE_ENTRY(entry, false); |
927 | } | |
f3f096cf | 928 | |
56de7630 MH |
929 | if (print_probe_args(s, tu->tp.args, tu->tp.nr_args, data, entry) < 0) |
930 | goto out; | |
f3f096cf | 931 | |
8579a107 | 932 | trace_seq_putc(s, '\n'); |
f3f096cf | 933 | |
8579a107 SRRH |
934 | out: |
935 | return trace_handle_return(s); | |
f3f096cf SD |
936 | } |
937 | ||
31ba3348 ON |
938 | typedef bool (*filter_func_t)(struct uprobe_consumer *self, |
939 | enum uprobe_filter_ctx ctx, | |
940 | struct mm_struct *mm); | |
941 | ||
942 | static int | |
7f1d2f82 | 943 | probe_event_enable(struct trace_uprobe *tu, struct trace_event_file *file, |
70ed91c6 | 944 | filter_func_t filter) |
f3f096cf | 945 | { |
70ed91c6 J |
946 | bool enabled = trace_probe_is_enabled(&tu->tp); |
947 | struct event_file_link *link = NULL; | |
948 | int ret; | |
949 | ||
950 | if (file) { | |
48212542 ON |
951 | if (tu->tp.flags & TP_FLAG_PROFILE) |
952 | return -EINTR; | |
953 | ||
70ed91c6 J |
954 | link = kmalloc(sizeof(*link), GFP_KERNEL); |
955 | if (!link) | |
956 | return -ENOMEM; | |
957 | ||
958 | link->file = file; | |
959 | list_add_tail_rcu(&link->list, &tu->tp.files); | |
960 | ||
961 | tu->tp.flags |= TP_FLAG_TRACE; | |
48212542 ON |
962 | } else { |
963 | if (tu->tp.flags & TP_FLAG_TRACE) | |
964 | return -EINTR; | |
965 | ||
70ed91c6 | 966 | tu->tp.flags |= TP_FLAG_PROFILE; |
48212542 | 967 | } |
f3f096cf | 968 | |
736288ba ON |
969 | WARN_ON(!uprobe_filter_is_empty(&tu->filter)); |
970 | ||
70ed91c6 J |
971 | if (enabled) |
972 | return 0; | |
973 | ||
fb6bab6a ON |
974 | ret = uprobe_buffer_enable(); |
975 | if (ret) | |
976 | goto err_flags; | |
977 | ||
31ba3348 | 978 | tu->consumer.filter = filter; |
0c92c7a3 | 979 | tu->inode = d_real_inode(tu->path.dentry); |
1cc33161 RB |
980 | if (tu->ref_ctr_offset) { |
981 | ret = uprobe_register_refctr(tu->inode, tu->offset, | |
982 | tu->ref_ctr_offset, &tu->consumer); | |
983 | } else { | |
984 | ret = uprobe_register(tu->inode, tu->offset, &tu->consumer); | |
985 | } | |
986 | ||
fb6bab6a ON |
987 | if (ret) |
988 | goto err_buffer; | |
989 | ||
990 | return 0; | |
991 | ||
992 | err_buffer: | |
993 | uprobe_buffer_disable(); | |
f3f096cf | 994 | |
fb6bab6a ON |
995 | err_flags: |
996 | if (file) { | |
997 | list_del(&link->list); | |
998 | kfree(link); | |
999 | tu->tp.flags &= ~TP_FLAG_TRACE; | |
1000 | } else { | |
1001 | tu->tp.flags &= ~TP_FLAG_PROFILE; | |
1002 | } | |
4161824f | 1003 | return ret; |
f3f096cf SD |
1004 | } |
1005 | ||
70ed91c6 | 1006 | static void |
7f1d2f82 | 1007 | probe_event_disable(struct trace_uprobe *tu, struct trace_event_file *file) |
f3f096cf | 1008 | { |
14577c39 | 1009 | if (!trace_probe_is_enabled(&tu->tp)) |
f3f096cf SD |
1010 | return; |
1011 | ||
70ed91c6 J |
1012 | if (file) { |
1013 | struct event_file_link *link; | |
1014 | ||
1015 | link = find_event_file_link(&tu->tp, file); | |
1016 | if (!link) | |
1017 | return; | |
1018 | ||
1019 | list_del_rcu(&link->list); | |
1020 | /* synchronize with u{,ret}probe_trace_func */ | |
016f8ffc | 1021 | synchronize_rcu(); |
70ed91c6 J |
1022 | kfree(link); |
1023 | ||
1024 | if (!list_empty(&tu->tp.files)) | |
1025 | return; | |
1026 | } | |
1027 | ||
736288ba ON |
1028 | WARN_ON(!uprobe_filter_is_empty(&tu->filter)); |
1029 | ||
a932b738 | 1030 | uprobe_unregister(tu->inode, tu->offset, &tu->consumer); |
0c92c7a3 | 1031 | tu->inode = NULL; |
70ed91c6 | 1032 | tu->tp.flags &= file ? ~TP_FLAG_TRACE : ~TP_FLAG_PROFILE; |
dcad1a20 NK |
1033 | |
1034 | uprobe_buffer_disable(); | |
f3f096cf SD |
1035 | } |
1036 | ||
2425bcb9 | 1037 | static int uprobe_event_define_fields(struct trace_event_call *event_call) |
f3f096cf | 1038 | { |
eeb07b06 | 1039 | int ret, size; |
f3f096cf | 1040 | struct uprobe_trace_entry_head field; |
457d1772 | 1041 | struct trace_uprobe *tu = event_call->data; |
f3f096cf | 1042 | |
4d1298e2 ON |
1043 | if (is_ret_probe(tu)) { |
1044 | DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_FUNC, 0); | |
1045 | DEFINE_FIELD(unsigned long, vaddr[1], FIELD_STRING_RETIP, 0); | |
1046 | size = SIZEOF_TRACE_ENTRY(true); | |
1047 | } else { | |
1048 | DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0); | |
1049 | size = SIZEOF_TRACE_ENTRY(false); | |
1050 | } | |
f3f096cf | 1051 | |
eeb07b06 | 1052 | return traceprobe_define_arg_fields(event_call, size, &tu->tp); |
f3f096cf SD |
1053 | } |
1054 | ||
f3f096cf | 1055 | #ifdef CONFIG_PERF_EVENTS |
31ba3348 ON |
1056 | static bool |
1057 | __uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm) | |
1058 | { | |
1059 | struct perf_event *event; | |
1060 | ||
1061 | if (filter->nr_systemwide) | |
1062 | return true; | |
1063 | ||
1064 | list_for_each_entry(event, &filter->perf_events, hw.tp_list) { | |
50f16a8b | 1065 | if (event->hw.target->mm == mm) |
31ba3348 ON |
1066 | return true; |
1067 | } | |
1068 | ||
1069 | return false; | |
1070 | } | |
1071 | ||
b2fe8ba6 ON |
1072 | static inline bool |
1073 | uprobe_filter_event(struct trace_uprobe *tu, struct perf_event *event) | |
1074 | { | |
50f16a8b | 1075 | return __uprobe_perf_filter(&tu->filter, event->hw.target->mm); |
b2fe8ba6 ON |
1076 | } |
1077 | ||
ce5f36a5 | 1078 | static int uprobe_perf_close(struct trace_uprobe *tu, struct perf_event *event) |
736288ba | 1079 | { |
b2fe8ba6 ON |
1080 | bool done; |
1081 | ||
736288ba | 1082 | write_lock(&tu->filter.rwlock); |
50f16a8b | 1083 | if (event->hw.target) { |
ce5f36a5 | 1084 | list_del(&event->hw.tp_list); |
b2fe8ba6 | 1085 | done = tu->filter.nr_systemwide || |
50f16a8b | 1086 | (event->hw.target->flags & PF_EXITING) || |
b2fe8ba6 | 1087 | uprobe_filter_event(tu, event); |
b2fe8ba6 | 1088 | } else { |
ce5f36a5 | 1089 | tu->filter.nr_systemwide--; |
b2fe8ba6 | 1090 | done = tu->filter.nr_systemwide; |
b2fe8ba6 | 1091 | } |
736288ba ON |
1092 | write_unlock(&tu->filter.rwlock); |
1093 | ||
b2fe8ba6 | 1094 | if (!done) |
927d6874 | 1095 | return uprobe_apply(tu->inode, tu->offset, &tu->consumer, false); |
31ba3348 | 1096 | |
736288ba ON |
1097 | return 0; |
1098 | } | |
1099 | ||
ce5f36a5 | 1100 | static int uprobe_perf_open(struct trace_uprobe *tu, struct perf_event *event) |
736288ba | 1101 | { |
b2fe8ba6 | 1102 | bool done; |
927d6874 | 1103 | int err; |
b2fe8ba6 | 1104 | |
736288ba | 1105 | write_lock(&tu->filter.rwlock); |
50f16a8b | 1106 | if (event->hw.target) { |
ce5f36a5 ON |
1107 | /* |
1108 | * event->parent != NULL means copy_process(), we can avoid | |
1109 | * uprobe_apply(). current->mm must be probed and we can rely | |
1110 | * on dup_mmap() which preserves the already installed bp's. | |
1111 | * | |
1112 | * attr.enable_on_exec means that exec/mmap will install the | |
1113 | * breakpoints we need. | |
1114 | */ | |
b2fe8ba6 | 1115 | done = tu->filter.nr_systemwide || |
ce5f36a5 | 1116 | event->parent || event->attr.enable_on_exec || |
b2fe8ba6 | 1117 | uprobe_filter_event(tu, event); |
ce5f36a5 | 1118 | list_add(&event->hw.tp_list, &tu->filter.perf_events); |
b2fe8ba6 | 1119 | } else { |
b2fe8ba6 | 1120 | done = tu->filter.nr_systemwide; |
ce5f36a5 | 1121 | tu->filter.nr_systemwide++; |
b2fe8ba6 | 1122 | } |
736288ba ON |
1123 | write_unlock(&tu->filter.rwlock); |
1124 | ||
927d6874 ON |
1125 | err = 0; |
1126 | if (!done) { | |
1127 | err = uprobe_apply(tu->inode, tu->offset, &tu->consumer, true); | |
1128 | if (err) | |
1129 | uprobe_perf_close(tu, event); | |
1130 | } | |
1131 | return err; | |
736288ba ON |
1132 | } |
1133 | ||
31ba3348 ON |
1134 | static bool uprobe_perf_filter(struct uprobe_consumer *uc, |
1135 | enum uprobe_filter_ctx ctx, struct mm_struct *mm) | |
1136 | { | |
1137 | struct trace_uprobe *tu; | |
1138 | int ret; | |
1139 | ||
1140 | tu = container_of(uc, struct trace_uprobe, consumer); | |
1141 | read_lock(&tu->filter.rwlock); | |
1142 | ret = __uprobe_perf_filter(&tu->filter, mm); | |
1143 | read_unlock(&tu->filter.rwlock); | |
1144 | ||
1145 | return ret; | |
1146 | } | |
1147 | ||
a43b9704 | 1148 | static void __uprobe_perf_func(struct trace_uprobe *tu, |
dd9fa555 NK |
1149 | unsigned long func, struct pt_regs *regs, |
1150 | struct uprobe_cpu_buffer *ucb, int dsize) | |
f3f096cf | 1151 | { |
2425bcb9 | 1152 | struct trace_event_call *call = &tu->tp.call; |
f3f096cf SD |
1153 | struct uprobe_trace_entry_head *entry; |
1154 | struct hlist_head *head; | |
457d1772 | 1155 | void *data; |
dd9fa555 | 1156 | int size, esize; |
dcad1a20 NK |
1157 | int rctx; |
1158 | ||
e87c6bc3 | 1159 | if (bpf_prog_array_valid(call) && !trace_call_bpf(call, regs)) |
04a22fae WN |
1160 | return; |
1161 | ||
dcad1a20 | 1162 | esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); |
f3f096cf | 1163 | |
dcad1a20 NK |
1164 | size = esize + tu->tp.size + dsize; |
1165 | size = ALIGN(size + sizeof(u32), sizeof(u64)) - sizeof(u32); | |
1166 | if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough")) | |
1167 | return; | |
1168 | ||
f3f096cf | 1169 | preempt_disable(); |
515619f2 ON |
1170 | head = this_cpu_ptr(call->perf_events); |
1171 | if (hlist_empty(head)) | |
1172 | goto out; | |
1173 | ||
1e1dcd93 | 1174 | entry = perf_trace_buf_alloc(size, NULL, &rctx); |
f3f096cf SD |
1175 | if (!entry) |
1176 | goto out; | |
1177 | ||
393a736c ON |
1178 | if (is_ret_probe(tu)) { |
1179 | entry->vaddr[0] = func; | |
32520b2c | 1180 | entry->vaddr[1] = instruction_pointer(regs); |
393a736c ON |
1181 | data = DATAOF_TRACE_ENTRY(entry, true); |
1182 | } else { | |
32520b2c | 1183 | entry->vaddr[0] = instruction_pointer(regs); |
393a736c ON |
1184 | data = DATAOF_TRACE_ENTRY(entry, false); |
1185 | } | |
1186 | ||
dcad1a20 NK |
1187 | memcpy(data, ucb->buf, tu->tp.size + dsize); |
1188 | ||
1189 | if (size - esize > tu->tp.size + dsize) { | |
1190 | int len = tu->tp.size + dsize; | |
14577c39 | 1191 | |
dcad1a20 | 1192 | memset(data + len, 0, size - esize - len); |
14577c39 | 1193 | } |
f3f096cf | 1194 | |
1e1dcd93 | 1195 | perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, |
8fd0fbbe | 1196 | head, NULL); |
f3f096cf SD |
1197 | out: |
1198 | preempt_enable(); | |
a51cc604 ON |
1199 | } |
1200 | ||
1201 | /* uprobe profile handler */ | |
dd9fa555 NK |
1202 | static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs, |
1203 | struct uprobe_cpu_buffer *ucb, int dsize) | |
a51cc604 ON |
1204 | { |
1205 | if (!uprobe_perf_filter(&tu->consumer, 0, current->mm)) | |
1206 | return UPROBE_HANDLER_REMOVE; | |
1207 | ||
393a736c | 1208 | if (!is_ret_probe(tu)) |
dd9fa555 | 1209 | __uprobe_perf_func(tu, 0, regs, ucb, dsize); |
f42d24a1 | 1210 | return 0; |
f3f096cf | 1211 | } |
c1ae5c75 ON |
1212 | |
1213 | static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func, | |
dd9fa555 NK |
1214 | struct pt_regs *regs, |
1215 | struct uprobe_cpu_buffer *ucb, int dsize) | |
c1ae5c75 | 1216 | { |
dd9fa555 | 1217 | __uprobe_perf_func(tu, func, regs, ucb, dsize); |
c1ae5c75 | 1218 | } |
41bdc4b4 YS |
1219 | |
1220 | int bpf_get_uprobe_info(const struct perf_event *event, u32 *fd_type, | |
1221 | const char **filename, u64 *probe_offset, | |
1222 | bool perf_type_tracepoint) | |
1223 | { | |
1224 | const char *pevent = trace_event_name(event->tp_event); | |
1225 | const char *group = event->tp_event->class->system; | |
1226 | struct trace_uprobe *tu; | |
1227 | ||
1228 | if (perf_type_tracepoint) | |
1229 | tu = find_probe_event(pevent, group); | |
1230 | else | |
1231 | tu = event->tp_event->data; | |
1232 | if (!tu) | |
1233 | return -EINVAL; | |
1234 | ||
1235 | *fd_type = is_ret_probe(tu) ? BPF_FD_TYPE_URETPROBE | |
1236 | : BPF_FD_TYPE_UPROBE; | |
1237 | *filename = tu->filename; | |
1238 | *probe_offset = tu->offset; | |
1239 | return 0; | |
1240 | } | |
f3f096cf SD |
1241 | #endif /* CONFIG_PERF_EVENTS */ |
1242 | ||
70ed91c6 | 1243 | static int |
2425bcb9 | 1244 | trace_uprobe_register(struct trace_event_call *event, enum trace_reg type, |
70ed91c6 | 1245 | void *data) |
f3f096cf | 1246 | { |
457d1772 | 1247 | struct trace_uprobe *tu = event->data; |
7f1d2f82 | 1248 | struct trace_event_file *file = data; |
f3f096cf SD |
1249 | |
1250 | switch (type) { | |
1251 | case TRACE_REG_REGISTER: | |
70ed91c6 | 1252 | return probe_event_enable(tu, file, NULL); |
f3f096cf SD |
1253 | |
1254 | case TRACE_REG_UNREGISTER: | |
70ed91c6 | 1255 | probe_event_disable(tu, file); |
f3f096cf SD |
1256 | return 0; |
1257 | ||
1258 | #ifdef CONFIG_PERF_EVENTS | |
1259 | case TRACE_REG_PERF_REGISTER: | |
70ed91c6 | 1260 | return probe_event_enable(tu, NULL, uprobe_perf_filter); |
f3f096cf SD |
1261 | |
1262 | case TRACE_REG_PERF_UNREGISTER: | |
70ed91c6 | 1263 | probe_event_disable(tu, NULL); |
f3f096cf | 1264 | return 0; |
736288ba ON |
1265 | |
1266 | case TRACE_REG_PERF_OPEN: | |
1267 | return uprobe_perf_open(tu, data); | |
1268 | ||
1269 | case TRACE_REG_PERF_CLOSE: | |
1270 | return uprobe_perf_close(tu, data); | |
1271 | ||
f3f096cf SD |
1272 | #endif |
1273 | default: | |
1274 | return 0; | |
1275 | } | |
1276 | return 0; | |
1277 | } | |
1278 | ||
1279 | static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs) | |
1280 | { | |
f3f096cf | 1281 | struct trace_uprobe *tu; |
b7e0bf34 | 1282 | struct uprobe_dispatch_data udd; |
dd9fa555 NK |
1283 | struct uprobe_cpu_buffer *ucb; |
1284 | int dsize, esize; | |
f42d24a1 | 1285 | int ret = 0; |
f3f096cf | 1286 | |
dd9fa555 | 1287 | |
a932b738 | 1288 | tu = container_of(con, struct trace_uprobe, consumer); |
1b47aefd | 1289 | tu->nhit++; |
f3f096cf | 1290 | |
b7e0bf34 NK |
1291 | udd.tu = tu; |
1292 | udd.bp_addr = instruction_pointer(regs); | |
1293 | ||
1294 | current->utask->vaddr = (unsigned long) &udd; | |
1295 | ||
dd9fa555 NK |
1296 | if (WARN_ON_ONCE(!uprobe_cpu_buffer)) |
1297 | return 0; | |
1298 | ||
1299 | dsize = __get_data_size(&tu->tp, regs); | |
1300 | esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); | |
1301 | ||
1302 | ucb = uprobe_buffer_get(); | |
1303 | store_trace_args(esize, &tu->tp, regs, ucb->buf, dsize); | |
1304 | ||
14577c39 | 1305 | if (tu->tp.flags & TP_FLAG_TRACE) |
dd9fa555 | 1306 | ret |= uprobe_trace_func(tu, regs, ucb, dsize); |
f3f096cf SD |
1307 | |
1308 | #ifdef CONFIG_PERF_EVENTS | |
14577c39 | 1309 | if (tu->tp.flags & TP_FLAG_PROFILE) |
dd9fa555 | 1310 | ret |= uprobe_perf_func(tu, regs, ucb, dsize); |
f3f096cf | 1311 | #endif |
dd9fa555 | 1312 | uprobe_buffer_put(ucb); |
f42d24a1 | 1313 | return ret; |
f3f096cf SD |
1314 | } |
1315 | ||
c1ae5c75 ON |
1316 | static int uretprobe_dispatcher(struct uprobe_consumer *con, |
1317 | unsigned long func, struct pt_regs *regs) | |
1318 | { | |
1319 | struct trace_uprobe *tu; | |
b7e0bf34 | 1320 | struct uprobe_dispatch_data udd; |
dd9fa555 NK |
1321 | struct uprobe_cpu_buffer *ucb; |
1322 | int dsize, esize; | |
c1ae5c75 ON |
1323 | |
1324 | tu = container_of(con, struct trace_uprobe, consumer); | |
1325 | ||
b7e0bf34 NK |
1326 | udd.tu = tu; |
1327 | udd.bp_addr = func; | |
1328 | ||
1329 | current->utask->vaddr = (unsigned long) &udd; | |
1330 | ||
dd9fa555 NK |
1331 | if (WARN_ON_ONCE(!uprobe_cpu_buffer)) |
1332 | return 0; | |
1333 | ||
1334 | dsize = __get_data_size(&tu->tp, regs); | |
1335 | esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); | |
1336 | ||
1337 | ucb = uprobe_buffer_get(); | |
1338 | store_trace_args(esize, &tu->tp, regs, ucb->buf, dsize); | |
1339 | ||
14577c39 | 1340 | if (tu->tp.flags & TP_FLAG_TRACE) |
dd9fa555 | 1341 | uretprobe_trace_func(tu, func, regs, ucb, dsize); |
c1ae5c75 ON |
1342 | |
1343 | #ifdef CONFIG_PERF_EVENTS | |
14577c39 | 1344 | if (tu->tp.flags & TP_FLAG_PROFILE) |
dd9fa555 | 1345 | uretprobe_perf_func(tu, func, regs, ucb, dsize); |
c1ae5c75 | 1346 | #endif |
dd9fa555 | 1347 | uprobe_buffer_put(ucb); |
c1ae5c75 ON |
1348 | return 0; |
1349 | } | |
1350 | ||
f3f096cf SD |
1351 | static struct trace_event_functions uprobe_funcs = { |
1352 | .trace = print_uprobe_event | |
1353 | }; | |
1354 | ||
33ea4b24 SL |
1355 | static inline void init_trace_event_call(struct trace_uprobe *tu, |
1356 | struct trace_event_call *call) | |
f3f096cf | 1357 | { |
f3f096cf SD |
1358 | INIT_LIST_HEAD(&call->class->fields); |
1359 | call->event.funcs = &uprobe_funcs; | |
1360 | call->class->define_fields = uprobe_event_define_fields; | |
1361 | ||
33ea4b24 SL |
1362 | call->flags = TRACE_EVENT_FL_UPROBE; |
1363 | call->class->reg = trace_uprobe_register; | |
1364 | call->data = tu; | |
1365 | } | |
1366 | ||
1367 | static int register_uprobe_event(struct trace_uprobe *tu) | |
1368 | { | |
1369 | struct trace_event_call *call = &tu->tp.call; | |
1370 | int ret = 0; | |
1371 | ||
1372 | init_trace_event_call(tu, call); | |
1373 | ||
5bf652aa | 1374 | if (set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0) |
f3f096cf SD |
1375 | return -ENOMEM; |
1376 | ||
9023c930 | 1377 | ret = register_trace_event(&call->event); |
f3f096cf SD |
1378 | if (!ret) { |
1379 | kfree(call->print_fmt); | |
1380 | return -ENODEV; | |
1381 | } | |
ede392a7 | 1382 | |
f3f096cf SD |
1383 | ret = trace_add_event_call(call); |
1384 | ||
1385 | if (ret) { | |
de7b2973 | 1386 | pr_info("Failed to register uprobe event: %s\n", |
687fcc4a | 1387 | trace_event_name(call)); |
f3f096cf | 1388 | kfree(call->print_fmt); |
9023c930 | 1389 | unregister_trace_event(&call->event); |
f3f096cf SD |
1390 | } |
1391 | ||
1392 | return ret; | |
1393 | } | |
1394 | ||
c6c2401d | 1395 | static int unregister_uprobe_event(struct trace_uprobe *tu) |
f3f096cf | 1396 | { |
c6c2401d SRRH |
1397 | int ret; |
1398 | ||
f3f096cf | 1399 | /* tu->event is unregistered in trace_remove_event_call() */ |
14577c39 | 1400 | ret = trace_remove_event_call(&tu->tp.call); |
c6c2401d SRRH |
1401 | if (ret) |
1402 | return ret; | |
14577c39 NK |
1403 | kfree(tu->tp.call.print_fmt); |
1404 | tu->tp.call.print_fmt = NULL; | |
c6c2401d | 1405 | return 0; |
f3f096cf SD |
1406 | } |
1407 | ||
33ea4b24 SL |
1408 | #ifdef CONFIG_PERF_EVENTS |
1409 | struct trace_event_call * | |
a6ca88b2 SL |
1410 | create_local_trace_uprobe(char *name, unsigned long offs, |
1411 | unsigned long ref_ctr_offset, bool is_return) | |
33ea4b24 SL |
1412 | { |
1413 | struct trace_uprobe *tu; | |
33ea4b24 SL |
1414 | struct path path; |
1415 | int ret; | |
1416 | ||
1417 | ret = kern_path(name, LOOKUP_FOLLOW, &path); | |
1418 | if (ret) | |
1419 | return ERR_PTR(ret); | |
1420 | ||
0c92c7a3 SL |
1421 | if (!d_is_reg(path.dentry)) { |
1422 | path_put(&path); | |
33ea4b24 SL |
1423 | return ERR_PTR(-EINVAL); |
1424 | } | |
1425 | ||
1426 | /* | |
1427 | * local trace_kprobes are not added to probe_list, so they are never | |
1428 | * searched in find_trace_kprobe(). Therefore, there is no concern of | |
1429 | * duplicated name "DUMMY_EVENT" here. | |
1430 | */ | |
1431 | tu = alloc_trace_uprobe(UPROBE_EVENT_SYSTEM, "DUMMY_EVENT", 0, | |
1432 | is_return); | |
1433 | ||
1434 | if (IS_ERR(tu)) { | |
1435 | pr_info("Failed to allocate trace_uprobe.(%d)\n", | |
1436 | (int)PTR_ERR(tu)); | |
0c92c7a3 | 1437 | path_put(&path); |
33ea4b24 SL |
1438 | return ERR_CAST(tu); |
1439 | } | |
1440 | ||
1441 | tu->offset = offs; | |
0c92c7a3 | 1442 | tu->path = path; |
a6ca88b2 | 1443 | tu->ref_ctr_offset = ref_ctr_offset; |
33ea4b24 SL |
1444 | tu->filename = kstrdup(name, GFP_KERNEL); |
1445 | init_trace_event_call(tu, &tu->tp.call); | |
1446 | ||
1447 | if (set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0) { | |
1448 | ret = -ENOMEM; | |
1449 | goto error; | |
1450 | } | |
1451 | ||
1452 | return &tu->tp.call; | |
1453 | error: | |
1454 | free_trace_uprobe(tu); | |
1455 | return ERR_PTR(ret); | |
1456 | } | |
1457 | ||
1458 | void destroy_local_trace_uprobe(struct trace_event_call *event_call) | |
1459 | { | |
1460 | struct trace_uprobe *tu; | |
1461 | ||
1462 | tu = container_of(event_call, struct trace_uprobe, tp.call); | |
1463 | ||
1464 | kfree(tu->tp.call.print_fmt); | |
1465 | tu->tp.call.print_fmt = NULL; | |
1466 | ||
1467 | free_trace_uprobe(tu); | |
1468 | } | |
1469 | #endif /* CONFIG_PERF_EVENTS */ | |
1470 | ||
f3f096cf SD |
1471 | /* Make a trace interface for controling probe points */ |
1472 | static __init int init_uprobe_trace(void) | |
1473 | { | |
1474 | struct dentry *d_tracer; | |
1475 | ||
1476 | d_tracer = tracing_init_dentry(); | |
14a5ae40 | 1477 | if (IS_ERR(d_tracer)) |
f3f096cf SD |
1478 | return 0; |
1479 | ||
1480 | trace_create_file("uprobe_events", 0644, d_tracer, | |
1481 | NULL, &uprobe_events_ops); | |
1482 | /* Profile interface */ | |
1483 | trace_create_file("uprobe_profile", 0444, d_tracer, | |
1484 | NULL, &uprobe_profile_ops); | |
1485 | return 0; | |
1486 | } | |
1487 | ||
1488 | fs_initcall(init_uprobe_trace); |