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 | */ | |
ea6eb5e7 | 8 | #define pr_fmt(fmt) "trace_uprobe: " fmt |
f3f096cf | 9 | |
0597c49c | 10 | #include <linux/ctype.h> |
f3f096cf SD |
11 | #include <linux/module.h> |
12 | #include <linux/uaccess.h> | |
13 | #include <linux/uprobes.h> | |
14 | #include <linux/namei.h> | |
b2e902f0 | 15 | #include <linux/string.h> |
b2d09103 | 16 | #include <linux/rculist.h> |
f3f096cf | 17 | |
0597c49c | 18 | #include "trace_dynevent.h" |
f3f096cf | 19 | #include "trace_probe.h" |
53305928 | 20 | #include "trace_probe_tmpl.h" |
f3f096cf SD |
21 | |
22 | #define UPROBE_EVENT_SYSTEM "uprobes" | |
23 | ||
457d1772 ON |
24 | struct uprobe_trace_entry_head { |
25 | struct trace_entry ent; | |
26 | unsigned long vaddr[]; | |
27 | }; | |
28 | ||
29 | #define SIZEOF_TRACE_ENTRY(is_return) \ | |
30 | (sizeof(struct uprobe_trace_entry_head) + \ | |
31 | sizeof(unsigned long) * (is_return ? 2 : 1)) | |
32 | ||
33 | #define DATAOF_TRACE_ENTRY(entry, is_return) \ | |
34 | ((void*)(entry) + SIZEOF_TRACE_ENTRY(is_return)) | |
35 | ||
736288ba ON |
36 | struct trace_uprobe_filter { |
37 | rwlock_t rwlock; | |
38 | int nr_systemwide; | |
39 | struct list_head perf_events; | |
40 | }; | |
41 | ||
0597c49c MH |
42 | static int trace_uprobe_create(int argc, const char **argv); |
43 | static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev); | |
44 | static int trace_uprobe_release(struct dyn_event *ev); | |
45 | static bool trace_uprobe_is_busy(struct dyn_event *ev); | |
46 | static bool trace_uprobe_match(const char *system, const char *event, | |
47 | struct dyn_event *ev); | |
48 | ||
49 | static struct dyn_event_operations trace_uprobe_ops = { | |
50 | .create = trace_uprobe_create, | |
51 | .show = trace_uprobe_show, | |
52 | .is_busy = trace_uprobe_is_busy, | |
53 | .free = trace_uprobe_release, | |
54 | .match = trace_uprobe_match, | |
55 | }; | |
56 | ||
f3f096cf SD |
57 | /* |
58 | * uprobe event core functions | |
59 | */ | |
f3f096cf | 60 | struct trace_uprobe { |
0597c49c | 61 | struct dyn_event devent; |
736288ba | 62 | struct trace_uprobe_filter filter; |
a932b738 | 63 | struct uprobe_consumer consumer; |
0c92c7a3 | 64 | struct path path; |
f3f096cf SD |
65 | struct inode *inode; |
66 | char *filename; | |
67 | unsigned long offset; | |
1cc33161 | 68 | unsigned long ref_ctr_offset; |
f3f096cf | 69 | unsigned long nhit; |
14577c39 | 70 | struct trace_probe tp; |
f3f096cf SD |
71 | }; |
72 | ||
0597c49c MH |
73 | static bool is_trace_uprobe(struct dyn_event *ev) |
74 | { | |
75 | return ev->ops == &trace_uprobe_ops; | |
76 | } | |
77 | ||
78 | static struct trace_uprobe *to_trace_uprobe(struct dyn_event *ev) | |
79 | { | |
80 | return container_of(ev, struct trace_uprobe, devent); | |
81 | } | |
82 | ||
83 | /** | |
84 | * for_each_trace_uprobe - iterate over the trace_uprobe list | |
85 | * @pos: the struct trace_uprobe * for each entry | |
86 | * @dpos: the struct dyn_event * to use as a loop cursor | |
87 | */ | |
88 | #define for_each_trace_uprobe(pos, dpos) \ | |
89 | for_each_dyn_event(dpos) \ | |
90 | if (is_trace_uprobe(dpos) && (pos = to_trace_uprobe(dpos))) | |
91 | ||
14577c39 NK |
92 | #define SIZEOF_TRACE_UPROBE(n) \ |
93 | (offsetof(struct trace_uprobe, tp.args) + \ | |
f3f096cf SD |
94 | (sizeof(struct probe_arg) * (n))) |
95 | ||
96 | static int register_uprobe_event(struct trace_uprobe *tu); | |
c6c2401d | 97 | static int unregister_uprobe_event(struct trace_uprobe *tu); |
f3f096cf | 98 | |
b7e0bf34 NK |
99 | struct uprobe_dispatch_data { |
100 | struct trace_uprobe *tu; | |
101 | unsigned long bp_addr; | |
102 | }; | |
103 | ||
f3f096cf | 104 | static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs); |
c1ae5c75 ON |
105 | static int uretprobe_dispatcher(struct uprobe_consumer *con, |
106 | unsigned long func, struct pt_regs *regs); | |
f3f096cf | 107 | |
3fd996a2 NK |
108 | #ifdef CONFIG_STACK_GROWSUP |
109 | static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n) | |
110 | { | |
111 | return addr - (n * sizeof(long)); | |
112 | } | |
113 | #else | |
114 | static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n) | |
115 | { | |
116 | return addr + (n * sizeof(long)); | |
117 | } | |
118 | #endif | |
119 | ||
120 | static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n) | |
121 | { | |
122 | unsigned long ret; | |
123 | unsigned long addr = user_stack_pointer(regs); | |
124 | ||
125 | addr = adjust_stack_addr(addr, n); | |
126 | ||
127 | if (copy_from_user(&ret, (void __force __user *) addr, sizeof(ret))) | |
128 | return 0; | |
129 | ||
130 | return ret; | |
131 | } | |
132 | ||
133 | /* | |
134 | * Uprobes-specific fetch functions | |
135 | */ | |
53305928 | 136 | static nokprobe_inline int |
9b960a38 | 137 | probe_mem_read(void *dest, void *src, size_t size) |
53305928 MH |
138 | { |
139 | void __user *vaddr = (void __force __user *)src; | |
140 | ||
f3f58935 | 141 | return copy_from_user(dest, vaddr, size) ? -EFAULT : 0; |
5baaa59e | 142 | } |
e65f7ae7 MH |
143 | |
144 | static nokprobe_inline int | |
145 | probe_mem_read_user(void *dest, void *src, size_t size) | |
146 | { | |
147 | return probe_mem_read(dest, src, size); | |
148 | } | |
149 | ||
5baaa59e NK |
150 | /* |
151 | * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max | |
152 | * length and relative data location. | |
153 | */ | |
9178412d MH |
154 | static nokprobe_inline int |
155 | fetch_store_string(unsigned long addr, void *dest, void *base) | |
5baaa59e NK |
156 | { |
157 | long ret; | |
9178412d MH |
158 | u32 loc = *(u32 *)dest; |
159 | int maxlen = get_loc_len(loc); | |
160 | u8 *dst = get_loc_data(dest, base); | |
5baaa59e NK |
161 | void __user *src = (void __force __user *) addr; |
162 | ||
9178412d MH |
163 | if (unlikely(!maxlen)) |
164 | return -ENOMEM; | |
5baaa59e | 165 | |
4dd537ac MH |
166 | if (addr == FETCH_TOKEN_COMM) |
167 | ret = strlcpy(dst, current->comm, maxlen); | |
168 | else | |
169 | ret = strncpy_from_user(dst, src, maxlen); | |
9178412d MH |
170 | if (ret >= 0) { |
171 | if (ret == maxlen) | |
172 | dst[ret - 1] = '\0'; | |
0722069a AZ |
173 | else |
174 | /* | |
175 | * Include the terminating null byte. In this case it | |
176 | * was copied by strncpy_from_user but not accounted | |
177 | * for in ret. | |
178 | */ | |
179 | ret++; | |
9178412d | 180 | *(u32 *)dest = make_data_loc(ret, (void *)dst - base); |
5baaa59e | 181 | } |
9178412d MH |
182 | |
183 | return ret; | |
5baaa59e NK |
184 | } |
185 | ||
88903c46 MH |
186 | static nokprobe_inline int |
187 | fetch_store_string_user(unsigned long addr, void *dest, void *base) | |
188 | { | |
189 | return fetch_store_string(addr, dest, base); | |
190 | } | |
191 | ||
53305928 | 192 | /* Return the length of string -- including null terminal byte */ |
9178412d MH |
193 | static nokprobe_inline int |
194 | fetch_store_strlen(unsigned long addr) | |
5baaa59e NK |
195 | { |
196 | int len; | |
197 | void __user *vaddr = (void __force __user *) addr; | |
198 | ||
4dd537ac MH |
199 | if (addr == FETCH_TOKEN_COMM) |
200 | len = strlen(current->comm) + 1; | |
201 | else | |
202 | len = strnlen_user(vaddr, MAX_STRING_SIZE); | |
5baaa59e | 203 | |
9178412d | 204 | return (len > MAX_STRING_SIZE) ? 0 : len; |
5baaa59e | 205 | } |
3fd996a2 | 206 | |
88903c46 MH |
207 | static nokprobe_inline int |
208 | fetch_store_strlen_user(unsigned long addr) | |
209 | { | |
210 | return fetch_store_strlen(addr); | |
211 | } | |
212 | ||
53305928 | 213 | static unsigned long translate_user_vaddr(unsigned long file_offset) |
b7e0bf34 NK |
214 | { |
215 | unsigned long base_addr; | |
216 | struct uprobe_dispatch_data *udd; | |
217 | ||
218 | udd = (void *) current->utask->vaddr; | |
219 | ||
220 | base_addr = udd->bp_addr - udd->tu->offset; | |
53305928 | 221 | return base_addr + file_offset; |
b7e0bf34 | 222 | } |
b7e0bf34 | 223 | |
53305928 MH |
224 | /* Note that we don't verify it, since the code does not come from user space */ |
225 | static int | |
226 | process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest, | |
9178412d | 227 | void *base) |
53305928 MH |
228 | { |
229 | unsigned long val; | |
53305928 MH |
230 | |
231 | /* 1st stage: get value from context */ | |
232 | switch (code->op) { | |
233 | case FETCH_OP_REG: | |
234 | val = regs_get_register(regs, code->param); | |
235 | break; | |
236 | case FETCH_OP_STACK: | |
237 | val = get_user_stack_nth(regs, code->param); | |
238 | break; | |
239 | case FETCH_OP_STACKP: | |
240 | val = user_stack_pointer(regs); | |
241 | break; | |
242 | case FETCH_OP_RETVAL: | |
243 | val = regs_return_value(regs); | |
244 | break; | |
245 | case FETCH_OP_IMM: | |
246 | val = code->immediate; | |
247 | break; | |
4dd537ac MH |
248 | case FETCH_OP_COMM: |
249 | val = FETCH_TOKEN_COMM; | |
250 | break; | |
53305928 MH |
251 | case FETCH_OP_FOFFS: |
252 | val = translate_user_vaddr(code->immediate); | |
253 | break; | |
254 | default: | |
255 | return -EILSEQ; | |
256 | } | |
257 | code++; | |
258 | ||
9b960a38 | 259 | return process_fetch_insn_bottom(code, val, dest, base); |
53305928 MH |
260 | } |
261 | NOKPROBE_SYMBOL(process_fetch_insn) | |
262 | ||
736288ba ON |
263 | static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter) |
264 | { | |
265 | rwlock_init(&filter->rwlock); | |
266 | filter->nr_systemwide = 0; | |
267 | INIT_LIST_HEAD(&filter->perf_events); | |
268 | } | |
269 | ||
270 | static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter) | |
271 | { | |
272 | return !filter->nr_systemwide && list_empty(&filter->perf_events); | |
273 | } | |
274 | ||
c1ae5c75 ON |
275 | static inline bool is_ret_probe(struct trace_uprobe *tu) |
276 | { | |
277 | return tu->consumer.ret_handler != NULL; | |
278 | } | |
279 | ||
0597c49c MH |
280 | static bool trace_uprobe_is_busy(struct dyn_event *ev) |
281 | { | |
282 | struct trace_uprobe *tu = to_trace_uprobe(ev); | |
283 | ||
284 | return trace_probe_is_enabled(&tu->tp); | |
285 | } | |
286 | ||
287 | static bool trace_uprobe_match(const char *system, const char *event, | |
288 | struct dyn_event *ev) | |
289 | { | |
290 | struct trace_uprobe *tu = to_trace_uprobe(ev); | |
291 | ||
b55ce203 MH |
292 | return strcmp(trace_probe_name(&tu->tp), event) == 0 && |
293 | (!system || strcmp(trace_probe_group_name(&tu->tp), system) == 0); | |
0597c49c MH |
294 | } |
295 | ||
f3f096cf SD |
296 | /* |
297 | * Allocate new trace_uprobe and initialize it (including uprobes). | |
298 | */ | |
299 | static struct trace_uprobe * | |
c1ae5c75 | 300 | alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret) |
f3f096cf SD |
301 | { |
302 | struct trace_uprobe *tu; | |
455b2899 | 303 | int ret; |
f3f096cf SD |
304 | |
305 | tu = kzalloc(SIZEOF_TRACE_UPROBE(nargs), GFP_KERNEL); | |
306 | if (!tu) | |
307 | return ERR_PTR(-ENOMEM); | |
308 | ||
455b2899 MH |
309 | ret = trace_probe_init(&tu->tp, event, group); |
310 | if (ret < 0) | |
f3f096cf SD |
311 | goto error; |
312 | ||
0597c49c | 313 | dyn_event_init(&tu->devent, &trace_uprobe_ops); |
a932b738 | 314 | tu->consumer.handler = uprobe_dispatcher; |
c1ae5c75 ON |
315 | if (is_ret) |
316 | tu->consumer.ret_handler = uretprobe_dispatcher; | |
736288ba | 317 | init_trace_uprobe_filter(&tu->filter); |
f3f096cf SD |
318 | return tu; |
319 | ||
320 | error: | |
f3f096cf SD |
321 | kfree(tu); |
322 | ||
455b2899 | 323 | return ERR_PTR(ret); |
f3f096cf SD |
324 | } |
325 | ||
326 | static void free_trace_uprobe(struct trace_uprobe *tu) | |
327 | { | |
0597c49c MH |
328 | if (!tu) |
329 | return; | |
330 | ||
0c92c7a3 | 331 | path_put(&tu->path); |
455b2899 | 332 | trace_probe_cleanup(&tu->tp); |
f3f096cf SD |
333 | kfree(tu->filename); |
334 | kfree(tu); | |
335 | } | |
336 | ||
337 | static struct trace_uprobe *find_probe_event(const char *event, const char *group) | |
338 | { | |
0597c49c | 339 | struct dyn_event *pos; |
f3f096cf SD |
340 | struct trace_uprobe *tu; |
341 | ||
0597c49c | 342 | for_each_trace_uprobe(tu, pos) |
b55ce203 MH |
343 | if (strcmp(trace_probe_name(&tu->tp), event) == 0 && |
344 | strcmp(trace_probe_group_name(&tu->tp), group) == 0) | |
f3f096cf SD |
345 | return tu; |
346 | ||
347 | return NULL; | |
348 | } | |
349 | ||
0597c49c | 350 | /* Unregister a trace_uprobe and probe_event */ |
c6c2401d | 351 | static int unregister_trace_uprobe(struct trace_uprobe *tu) |
f3f096cf | 352 | { |
c6c2401d SRRH |
353 | int ret; |
354 | ||
355 | ret = unregister_uprobe_event(tu); | |
356 | if (ret) | |
357 | return ret; | |
358 | ||
0597c49c | 359 | dyn_event_remove(&tu->devent); |
f3f096cf | 360 | free_trace_uprobe(tu); |
c6c2401d | 361 | return 0; |
f3f096cf SD |
362 | } |
363 | ||
ccea8727 RB |
364 | /* |
365 | * Uprobe with multiple reference counter is not allowed. i.e. | |
366 | * If inode and offset matches, reference counter offset *must* | |
367 | * match as well. Though, there is one exception: If user is | |
368 | * replacing old trace_uprobe with new one(same group/event), | |
369 | * then we allow same uprobe with new reference counter as far | |
370 | * as the new one does not conflict with any other existing | |
371 | * ones. | |
372 | */ | |
373 | static struct trace_uprobe *find_old_trace_uprobe(struct trace_uprobe *new) | |
374 | { | |
0597c49c | 375 | struct dyn_event *pos; |
ccea8727 RB |
376 | struct trace_uprobe *tmp, *old = NULL; |
377 | struct inode *new_inode = d_real_inode(new->path.dentry); | |
378 | ||
b55ce203 MH |
379 | old = find_probe_event(trace_probe_name(&new->tp), |
380 | trace_probe_group_name(&new->tp)); | |
ccea8727 | 381 | |
0597c49c | 382 | for_each_trace_uprobe(tmp, pos) { |
ccea8727 RB |
383 | if ((old ? old != tmp : true) && |
384 | new_inode == d_real_inode(tmp->path.dentry) && | |
385 | new->offset == tmp->offset && | |
386 | new->ref_ctr_offset != tmp->ref_ctr_offset) { | |
387 | pr_warn("Reference counter offset mismatch."); | |
388 | return ERR_PTR(-EINVAL); | |
389 | } | |
390 | } | |
391 | return old; | |
392 | } | |
393 | ||
f3f096cf SD |
394 | /* Register a trace_uprobe and probe_event */ |
395 | static int register_trace_uprobe(struct trace_uprobe *tu) | |
396 | { | |
14577c39 | 397 | struct trace_uprobe *old_tu; |
f3f096cf SD |
398 | int ret; |
399 | ||
0597c49c | 400 | mutex_lock(&event_mutex); |
f3f096cf SD |
401 | |
402 | /* register as an event */ | |
ccea8727 RB |
403 | old_tu = find_old_trace_uprobe(tu); |
404 | if (IS_ERR(old_tu)) { | |
405 | ret = PTR_ERR(old_tu); | |
406 | goto end; | |
407 | } | |
408 | ||
14577c39 | 409 | if (old_tu) { |
f3f096cf | 410 | /* delete old event */ |
14577c39 | 411 | ret = unregister_trace_uprobe(old_tu); |
c6c2401d SRRH |
412 | if (ret) |
413 | goto end; | |
414 | } | |
f3f096cf SD |
415 | |
416 | ret = register_uprobe_event(tu); | |
417 | if (ret) { | |
a395d6a7 | 418 | pr_warn("Failed to register probe event(%d)\n", ret); |
f3f096cf SD |
419 | goto end; |
420 | } | |
421 | ||
0597c49c | 422 | dyn_event_add(&tu->devent); |
f3f096cf SD |
423 | |
424 | end: | |
0597c49c | 425 | mutex_unlock(&event_mutex); |
f3f096cf SD |
426 | |
427 | return ret; | |
428 | } | |
429 | ||
430 | /* | |
431 | * Argument syntax: | |
306cfe20 | 432 | * - Add uprobe: p|r[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS] |
f3f096cf | 433 | */ |
0597c49c | 434 | static int trace_uprobe_create(int argc, const char **argv) |
f3f096cf SD |
435 | { |
436 | struct trace_uprobe *tu; | |
0597c49c MH |
437 | const char *event = NULL, *group = UPROBE_EVENT_SYSTEM; |
438 | char *arg, *filename, *rctr, *rctr_end, *tmp; | |
f3f096cf SD |
439 | char buf[MAX_EVENT_NAME_LEN]; |
440 | struct path path; | |
1cc33161 | 441 | unsigned long offset, ref_ctr_offset; |
0597c49c | 442 | bool is_return = false; |
f3f096cf SD |
443 | int i, ret; |
444 | ||
f3f096cf | 445 | ret = 0; |
1cc33161 | 446 | ref_ctr_offset = 0; |
f3f096cf | 447 | |
f01098c7 ET |
448 | switch (argv[0][0]) { |
449 | case 'r': | |
4ee5a52e | 450 | is_return = true; |
f01098c7 ET |
451 | break; |
452 | case 'p': | |
453 | break; | |
454 | default: | |
455 | return -ECANCELED; | |
456 | } | |
457 | ||
458 | if (argc < 2) | |
0597c49c | 459 | return -ECANCELED; |
f3f096cf | 460 | |
0597c49c | 461 | if (argv[0][1] == ':') |
f3f096cf | 462 | event = &argv[0][2]; |
f3f096cf | 463 | |
0597c49c MH |
464 | if (!strchr(argv[1], '/')) |
465 | return -ECANCELED; | |
f3f096cf | 466 | |
0597c49c MH |
467 | filename = kstrdup(argv[1], GFP_KERNEL); |
468 | if (!filename) | |
469 | return -ENOMEM; | |
f3f096cf | 470 | |
6496bb72 | 471 | /* Find the last occurrence, in case the path contains ':' too. */ |
0597c49c MH |
472 | arg = strrchr(filename, ':'); |
473 | if (!arg || !isdigit(arg[1])) { | |
474 | kfree(filename); | |
475 | return -ECANCELED; | |
476 | } | |
f3f096cf | 477 | |
ab105a4f MH |
478 | trace_probe_log_init("trace_uprobe", argc, argv); |
479 | trace_probe_log_set_index(1); /* filename is the 2nd argument */ | |
480 | ||
f3f096cf | 481 | *arg++ = '\0'; |
f3f096cf | 482 | ret = kern_path(filename, LOOKUP_FOLLOW, &path); |
0597c49c | 483 | if (ret) { |
ab105a4f | 484 | trace_probe_log_err(0, FILE_NOT_FOUND); |
0597c49c | 485 | kfree(filename); |
ab105a4f | 486 | trace_probe_log_clear(); |
0c92c7a3 | 487 | return ret; |
0597c49c | 488 | } |
0c92c7a3 | 489 | if (!d_is_reg(path.dentry)) { |
ab105a4f | 490 | trace_probe_log_err(0, NO_REGULAR_FILE); |
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, ')'); | |
ab105a4f MH |
499 | if (!rctr_end) { |
500 | ret = -EINVAL; | |
501 | rctr_end = rctr + strlen(rctr); | |
502 | trace_probe_log_err(rctr_end - filename, | |
503 | REFCNT_OPEN_BRACE); | |
504 | goto fail_address_parse; | |
505 | } else if (rctr_end[1] != '\0') { | |
1cc33161 | 506 | ret = -EINVAL; |
ab105a4f MH |
507 | trace_probe_log_err(rctr_end + 1 - filename, |
508 | BAD_REFCNT_SUFFIX); | |
1cc33161 RB |
509 | goto fail_address_parse; |
510 | } | |
511 | ||
512 | *rctr++ = '\0'; | |
513 | *rctr_end = '\0'; | |
514 | ret = kstrtoul(rctr, 0, &ref_ctr_offset); | |
515 | if (ret) { | |
ab105a4f | 516 | trace_probe_log_err(rctr - filename, BAD_REFCNT); |
1cc33161 RB |
517 | goto fail_address_parse; |
518 | } | |
519 | } | |
520 | ||
521 | /* Parse uprobe offset. */ | |
84d7ed79 | 522 | ret = kstrtoul(arg, 0, &offset); |
ab105a4f MH |
523 | if (ret) { |
524 | trace_probe_log_err(arg - filename, BAD_UPROBE_OFFS); | |
84d7ed79 | 525 | goto fail_address_parse; |
ab105a4f | 526 | } |
f3f096cf SD |
527 | |
528 | /* setup a probe */ | |
ab105a4f | 529 | trace_probe_log_set_index(0); |
0597c49c | 530 | if (event) { |
ab105a4f MH |
531 | ret = traceprobe_parse_event_name(&event, &group, buf, |
532 | event - argv[0]); | |
0597c49c MH |
533 | if (ret) |
534 | goto fail_address_parse; | |
535 | } else { | |
b2e902f0 | 536 | char *tail; |
f3f096cf SD |
537 | char *ptr; |
538 | ||
b2e902f0 AS |
539 | tail = kstrdup(kbasename(filename), GFP_KERNEL); |
540 | if (!tail) { | |
f3f096cf SD |
541 | ret = -ENOMEM; |
542 | goto fail_address_parse; | |
543 | } | |
544 | ||
f3f096cf SD |
545 | ptr = strpbrk(tail, ".-_"); |
546 | if (ptr) | |
547 | *ptr = '\0'; | |
548 | ||
549 | snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset); | |
550 | event = buf; | |
551 | kfree(tail); | |
552 | } | |
553 | ||
ab105a4f MH |
554 | argc -= 2; |
555 | argv += 2; | |
556 | ||
4ee5a52e | 557 | tu = alloc_trace_uprobe(group, event, argc, is_return); |
f3f096cf | 558 | if (IS_ERR(tu)) { |
f3f096cf | 559 | ret = PTR_ERR(tu); |
a039480e MH |
560 | /* This must return -ENOMEM otherwise there is a bug */ |
561 | WARN_ON_ONCE(ret != -ENOMEM); | |
f3f096cf SD |
562 | goto fail_address_parse; |
563 | } | |
564 | tu->offset = offset; | |
1cc33161 | 565 | tu->ref_ctr_offset = ref_ctr_offset; |
0c92c7a3 | 566 | tu->path = path; |
0597c49c | 567 | tu->filename = filename; |
f3f096cf SD |
568 | |
569 | /* parse arguments */ | |
f3f096cf | 570 | for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { |
0597c49c MH |
571 | tmp = kstrdup(argv[i], GFP_KERNEL); |
572 | if (!tmp) { | |
573 | ret = -ENOMEM; | |
574 | goto error; | |
575 | } | |
576 | ||
ab105a4f | 577 | trace_probe_log_set_index(i + 2); |
0597c49c | 578 | ret = traceprobe_parse_probe_arg(&tu->tp, i, tmp, |
a1303af5 | 579 | is_return ? TPARG_FL_RETURN : 0); |
0597c49c | 580 | kfree(tmp); |
d00bbea9 | 581 | if (ret) |
f3f096cf | 582 | goto error; |
f3f096cf SD |
583 | } |
584 | ||
b4d4b96b MH |
585 | ret = traceprobe_set_print_fmt(&tu->tp, is_ret_probe(tu)); |
586 | if (ret < 0) | |
587 | goto error; | |
588 | ||
f3f096cf | 589 | ret = register_trace_uprobe(tu); |
ab105a4f MH |
590 | if (!ret) |
591 | goto out; | |
f3f096cf SD |
592 | |
593 | error: | |
594 | free_trace_uprobe(tu); | |
ab105a4f MH |
595 | out: |
596 | trace_probe_log_clear(); | |
f3f096cf SD |
597 | return ret; |
598 | ||
599 | fail_address_parse: | |
ab105a4f | 600 | trace_probe_log_clear(); |
0c92c7a3 | 601 | path_put(&path); |
0597c49c | 602 | kfree(filename); |
f3f096cf | 603 | |
f3f096cf SD |
604 | return ret; |
605 | } | |
606 | ||
0597c49c | 607 | static int create_or_delete_trace_uprobe(int argc, char **argv) |
f3f096cf | 608 | { |
0597c49c | 609 | int ret; |
f3f096cf | 610 | |
0597c49c MH |
611 | if (argv[0][0] == '-') |
612 | return dyn_event_release(argc, argv, &trace_uprobe_ops); | |
f3f096cf | 613 | |
0597c49c MH |
614 | ret = trace_uprobe_create(argc, (const char **)argv); |
615 | return ret == -ECANCELED ? -EINVAL : ret; | |
f3f096cf SD |
616 | } |
617 | ||
0597c49c | 618 | static int trace_uprobe_release(struct dyn_event *ev) |
f3f096cf | 619 | { |
0597c49c | 620 | struct trace_uprobe *tu = to_trace_uprobe(ev); |
f3f096cf | 621 | |
0597c49c | 622 | return unregister_trace_uprobe(tu); |
f3f096cf SD |
623 | } |
624 | ||
0597c49c MH |
625 | /* Probes listing interfaces */ |
626 | static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev) | |
f3f096cf | 627 | { |
0597c49c | 628 | struct trace_uprobe *tu = to_trace_uprobe(ev); |
3ede82dd | 629 | char c = is_ret_probe(tu) ? 'r' : 'p'; |
f3f096cf SD |
630 | int i; |
631 | ||
b55ce203 MH |
632 | seq_printf(m, "%c:%s/%s %s:0x%0*lx", c, trace_probe_group_name(&tu->tp), |
633 | trace_probe_name(&tu->tp), tu->filename, | |
a64b2c01 | 634 | (int)(sizeof(void *) * 2), tu->offset); |
f3f096cf | 635 | |
1cc33161 RB |
636 | if (tu->ref_ctr_offset) |
637 | seq_printf(m, "(0x%lx)", tu->ref_ctr_offset); | |
638 | ||
14577c39 NK |
639 | for (i = 0; i < tu->tp.nr_args; i++) |
640 | seq_printf(m, " %s=%s", tu->tp.args[i].name, tu->tp.args[i].comm); | |
f3f096cf | 641 | |
fa6f0cc7 | 642 | seq_putc(m, '\n'); |
f3f096cf SD |
643 | return 0; |
644 | } | |
645 | ||
0597c49c MH |
646 | static int probes_seq_show(struct seq_file *m, void *v) |
647 | { | |
648 | struct dyn_event *ev = v; | |
649 | ||
650 | if (!is_trace_uprobe(ev)) | |
651 | return 0; | |
652 | ||
653 | return trace_uprobe_show(m, ev); | |
654 | } | |
655 | ||
f3f096cf | 656 | static const struct seq_operations probes_seq_op = { |
0597c49c MH |
657 | .start = dyn_event_seq_start, |
658 | .next = dyn_event_seq_next, | |
659 | .stop = dyn_event_seq_stop, | |
660 | .show = probes_seq_show | |
f3f096cf SD |
661 | }; |
662 | ||
663 | static int probes_open(struct inode *inode, struct file *file) | |
664 | { | |
c6c2401d SRRH |
665 | int ret; |
666 | ||
667 | if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { | |
0597c49c | 668 | ret = dyn_events_release_all(&trace_uprobe_ops); |
c6c2401d SRRH |
669 | if (ret) |
670 | return ret; | |
671 | } | |
f3f096cf SD |
672 | |
673 | return seq_open(file, &probes_seq_op); | |
674 | } | |
675 | ||
676 | static ssize_t probes_write(struct file *file, const char __user *buffer, | |
677 | size_t count, loff_t *ppos) | |
678 | { | |
0597c49c MH |
679 | return trace_parse_run_command(file, buffer, count, ppos, |
680 | create_or_delete_trace_uprobe); | |
f3f096cf SD |
681 | } |
682 | ||
683 | static const struct file_operations uprobe_events_ops = { | |
684 | .owner = THIS_MODULE, | |
685 | .open = probes_open, | |
686 | .read = seq_read, | |
687 | .llseek = seq_lseek, | |
688 | .release = seq_release, | |
689 | .write = probes_write, | |
690 | }; | |
691 | ||
692 | /* Probes profiling interfaces */ | |
693 | static int probes_profile_seq_show(struct seq_file *m, void *v) | |
694 | { | |
0597c49c MH |
695 | struct dyn_event *ev = v; |
696 | struct trace_uprobe *tu; | |
697 | ||
698 | if (!is_trace_uprobe(ev)) | |
699 | return 0; | |
f3f096cf | 700 | |
0597c49c | 701 | tu = to_trace_uprobe(ev); |
de7b2973 | 702 | seq_printf(m, " %s %-44s %15lu\n", tu->filename, |
b55ce203 | 703 | trace_probe_name(&tu->tp), tu->nhit); |
f3f096cf SD |
704 | return 0; |
705 | } | |
706 | ||
707 | static const struct seq_operations profile_seq_op = { | |
0597c49c MH |
708 | .start = dyn_event_seq_start, |
709 | .next = dyn_event_seq_next, | |
710 | .stop = dyn_event_seq_stop, | |
f3f096cf SD |
711 | .show = probes_profile_seq_show |
712 | }; | |
713 | ||
714 | static int profile_open(struct inode *inode, struct file *file) | |
715 | { | |
716 | return seq_open(file, &profile_seq_op); | |
717 | } | |
718 | ||
719 | static const struct file_operations uprobe_profile_ops = { | |
720 | .owner = THIS_MODULE, | |
721 | .open = profile_open, | |
722 | .read = seq_read, | |
723 | .llseek = seq_lseek, | |
724 | .release = seq_release, | |
725 | }; | |
726 | ||
dcad1a20 NK |
727 | struct uprobe_cpu_buffer { |
728 | struct mutex mutex; | |
729 | void *buf; | |
730 | }; | |
731 | static struct uprobe_cpu_buffer __percpu *uprobe_cpu_buffer; | |
732 | static int uprobe_buffer_refcnt; | |
733 | ||
734 | static int uprobe_buffer_init(void) | |
735 | { | |
736 | int cpu, err_cpu; | |
737 | ||
738 | uprobe_cpu_buffer = alloc_percpu(struct uprobe_cpu_buffer); | |
739 | if (uprobe_cpu_buffer == NULL) | |
740 | return -ENOMEM; | |
741 | ||
742 | for_each_possible_cpu(cpu) { | |
743 | struct page *p = alloc_pages_node(cpu_to_node(cpu), | |
744 | GFP_KERNEL, 0); | |
745 | if (p == NULL) { | |
746 | err_cpu = cpu; | |
747 | goto err; | |
748 | } | |
749 | per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf = page_address(p); | |
750 | mutex_init(&per_cpu_ptr(uprobe_cpu_buffer, cpu)->mutex); | |
751 | } | |
752 | ||
753 | return 0; | |
754 | ||
755 | err: | |
756 | for_each_possible_cpu(cpu) { | |
757 | if (cpu == err_cpu) | |
758 | break; | |
759 | free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf); | |
760 | } | |
761 | ||
762 | free_percpu(uprobe_cpu_buffer); | |
763 | return -ENOMEM; | |
764 | } | |
765 | ||
766 | static int uprobe_buffer_enable(void) | |
767 | { | |
768 | int ret = 0; | |
769 | ||
770 | BUG_ON(!mutex_is_locked(&event_mutex)); | |
771 | ||
772 | if (uprobe_buffer_refcnt++ == 0) { | |
773 | ret = uprobe_buffer_init(); | |
774 | if (ret < 0) | |
775 | uprobe_buffer_refcnt--; | |
776 | } | |
777 | ||
778 | return ret; | |
779 | } | |
780 | ||
781 | static void uprobe_buffer_disable(void) | |
782 | { | |
6ea6215f J |
783 | int cpu; |
784 | ||
dcad1a20 NK |
785 | BUG_ON(!mutex_is_locked(&event_mutex)); |
786 | ||
787 | if (--uprobe_buffer_refcnt == 0) { | |
6ea6215f J |
788 | for_each_possible_cpu(cpu) |
789 | free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer, | |
790 | cpu)->buf); | |
791 | ||
dcad1a20 NK |
792 | free_percpu(uprobe_cpu_buffer); |
793 | uprobe_cpu_buffer = NULL; | |
794 | } | |
795 | } | |
796 | ||
797 | static struct uprobe_cpu_buffer *uprobe_buffer_get(void) | |
798 | { | |
799 | struct uprobe_cpu_buffer *ucb; | |
800 | int cpu; | |
801 | ||
802 | cpu = raw_smp_processor_id(); | |
803 | ucb = per_cpu_ptr(uprobe_cpu_buffer, cpu); | |
804 | ||
805 | /* | |
806 | * Use per-cpu buffers for fastest access, but we might migrate | |
807 | * so the mutex makes sure we have sole access to it. | |
808 | */ | |
809 | mutex_lock(&ucb->mutex); | |
810 | ||
811 | return ucb; | |
812 | } | |
813 | ||
814 | static void uprobe_buffer_put(struct uprobe_cpu_buffer *ucb) | |
815 | { | |
816 | mutex_unlock(&ucb->mutex); | |
817 | } | |
818 | ||
a43b9704 | 819 | static void __uprobe_trace_func(struct trace_uprobe *tu, |
dd9fa555 | 820 | unsigned long func, struct pt_regs *regs, |
70ed91c6 | 821 | struct uprobe_cpu_buffer *ucb, int dsize, |
7f1d2f82 | 822 | struct trace_event_file *trace_file) |
f3f096cf SD |
823 | { |
824 | struct uprobe_trace_entry_head *entry; | |
825 | struct ring_buffer_event *event; | |
826 | struct ring_buffer *buffer; | |
457d1772 | 827 | void *data; |
dd9fa555 | 828 | int size, esize; |
e3dc9f89 | 829 | struct trace_event_call *call = trace_probe_event_call(&tu->tp); |
f3f096cf | 830 | |
7f1d2f82 | 831 | WARN_ON(call != trace_file->event_call); |
70ed91c6 | 832 | |
dd9fa555 | 833 | if (WARN_ON_ONCE(tu->tp.size + dsize > PAGE_SIZE)) |
dcad1a20 NK |
834 | return; |
835 | ||
09a5059a | 836 | if (trace_trigger_soft_disabled(trace_file)) |
ca3b1620 NK |
837 | return; |
838 | ||
dd9fa555 | 839 | esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); |
dcad1a20 | 840 | size = esize + tu->tp.size + dsize; |
7f1d2f82 | 841 | event = trace_event_buffer_lock_reserve(&buffer, trace_file, |
70ed91c6 | 842 | call->event.type, size, 0, 0); |
f3f096cf | 843 | if (!event) |
dd9fa555 | 844 | return; |
f3f096cf SD |
845 | |
846 | entry = ring_buffer_event_data(event); | |
393a736c ON |
847 | if (is_ret_probe(tu)) { |
848 | entry->vaddr[0] = func; | |
849 | entry->vaddr[1] = instruction_pointer(regs); | |
850 | data = DATAOF_TRACE_ENTRY(entry, true); | |
851 | } else { | |
852 | entry->vaddr[0] = instruction_pointer(regs); | |
853 | data = DATAOF_TRACE_ENTRY(entry, false); | |
854 | } | |
855 | ||
dcad1a20 | 856 | memcpy(data, ucb->buf, tu->tp.size + dsize); |
f3f096cf | 857 | |
7f1d2f82 | 858 | event_trigger_unlock_commit(trace_file, buffer, event, entry, 0, 0); |
a51cc604 | 859 | } |
f42d24a1 | 860 | |
a51cc604 | 861 | /* uprobe handler */ |
dd9fa555 NK |
862 | static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs, |
863 | struct uprobe_cpu_buffer *ucb, int dsize) | |
a51cc604 | 864 | { |
70ed91c6 J |
865 | struct event_file_link *link; |
866 | ||
867 | if (is_ret_probe(tu)) | |
868 | return 0; | |
869 | ||
870 | rcu_read_lock(); | |
b5f935ee | 871 | trace_probe_for_each_link_rcu(link, &tu->tp) |
70ed91c6 J |
872 | __uprobe_trace_func(tu, 0, regs, ucb, dsize, link->file); |
873 | rcu_read_unlock(); | |
874 | ||
f42d24a1 | 875 | return 0; |
f3f096cf SD |
876 | } |
877 | ||
c1ae5c75 | 878 | static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func, |
dd9fa555 NK |
879 | struct pt_regs *regs, |
880 | struct uprobe_cpu_buffer *ucb, int dsize) | |
c1ae5c75 | 881 | { |
70ed91c6 J |
882 | struct event_file_link *link; |
883 | ||
884 | rcu_read_lock(); | |
b5f935ee | 885 | trace_probe_for_each_link_rcu(link, &tu->tp) |
70ed91c6 J |
886 | __uprobe_trace_func(tu, func, regs, ucb, dsize, link->file); |
887 | rcu_read_unlock(); | |
c1ae5c75 ON |
888 | } |
889 | ||
f3f096cf SD |
890 | /* Event entry printers */ |
891 | static enum print_line_t | |
892 | print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event) | |
893 | { | |
457d1772 | 894 | struct uprobe_trace_entry_head *entry; |
f3f096cf SD |
895 | struct trace_seq *s = &iter->seq; |
896 | struct trace_uprobe *tu; | |
897 | u8 *data; | |
f3f096cf | 898 | |
457d1772 | 899 | entry = (struct uprobe_trace_entry_head *)iter->ent; |
14577c39 | 900 | tu = container_of(event, struct trace_uprobe, tp.call.event); |
f3f096cf | 901 | |
3ede82dd | 902 | if (is_ret_probe(tu)) { |
8579a107 | 903 | trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)", |
b55ce203 | 904 | trace_probe_name(&tu->tp), |
8579a107 | 905 | entry->vaddr[1], entry->vaddr[0]); |
3ede82dd ON |
906 | data = DATAOF_TRACE_ENTRY(entry, true); |
907 | } else { | |
8579a107 | 908 | trace_seq_printf(s, "%s: (0x%lx)", |
b55ce203 | 909 | trace_probe_name(&tu->tp), |
8579a107 | 910 | entry->vaddr[0]); |
3ede82dd ON |
911 | data = DATAOF_TRACE_ENTRY(entry, false); |
912 | } | |
f3f096cf | 913 | |
56de7630 MH |
914 | if (print_probe_args(s, tu->tp.args, tu->tp.nr_args, data, entry) < 0) |
915 | goto out; | |
f3f096cf | 916 | |
8579a107 | 917 | trace_seq_putc(s, '\n'); |
f3f096cf | 918 | |
8579a107 SRRH |
919 | out: |
920 | return trace_handle_return(s); | |
f3f096cf SD |
921 | } |
922 | ||
31ba3348 ON |
923 | typedef bool (*filter_func_t)(struct uprobe_consumer *self, |
924 | enum uprobe_filter_ctx ctx, | |
925 | struct mm_struct *mm); | |
926 | ||
927 | static int | |
7f1d2f82 | 928 | probe_event_enable(struct trace_uprobe *tu, struct trace_event_file *file, |
70ed91c6 | 929 | filter_func_t filter) |
f3f096cf | 930 | { |
70ed91c6 | 931 | bool enabled = trace_probe_is_enabled(&tu->tp); |
70ed91c6 J |
932 | int ret; |
933 | ||
934 | if (file) { | |
747774d6 | 935 | if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE)) |
48212542 ON |
936 | return -EINTR; |
937 | ||
b5f935ee MH |
938 | ret = trace_probe_add_file(&tu->tp, file); |
939 | if (ret < 0) | |
940 | return ret; | |
48212542 | 941 | } else { |
747774d6 | 942 | if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE)) |
48212542 ON |
943 | return -EINTR; |
944 | ||
747774d6 | 945 | trace_probe_set_flag(&tu->tp, TP_FLAG_PROFILE); |
48212542 | 946 | } |
f3f096cf | 947 | |
736288ba ON |
948 | WARN_ON(!uprobe_filter_is_empty(&tu->filter)); |
949 | ||
70ed91c6 J |
950 | if (enabled) |
951 | return 0; | |
952 | ||
fb6bab6a ON |
953 | ret = uprobe_buffer_enable(); |
954 | if (ret) | |
955 | goto err_flags; | |
956 | ||
31ba3348 | 957 | tu->consumer.filter = filter; |
0c92c7a3 | 958 | tu->inode = d_real_inode(tu->path.dentry); |
1cc33161 RB |
959 | if (tu->ref_ctr_offset) { |
960 | ret = uprobe_register_refctr(tu->inode, tu->offset, | |
961 | tu->ref_ctr_offset, &tu->consumer); | |
962 | } else { | |
963 | ret = uprobe_register(tu->inode, tu->offset, &tu->consumer); | |
964 | } | |
965 | ||
fb6bab6a ON |
966 | if (ret) |
967 | goto err_buffer; | |
968 | ||
969 | return 0; | |
970 | ||
971 | err_buffer: | |
972 | uprobe_buffer_disable(); | |
f3f096cf | 973 | |
fb6bab6a | 974 | err_flags: |
b5f935ee MH |
975 | if (file) |
976 | trace_probe_remove_file(&tu->tp, file); | |
977 | else | |
747774d6 | 978 | trace_probe_clear_flag(&tu->tp, TP_FLAG_PROFILE); |
b5f935ee | 979 | |
4161824f | 980 | return ret; |
f3f096cf SD |
981 | } |
982 | ||
70ed91c6 | 983 | static void |
7f1d2f82 | 984 | probe_event_disable(struct trace_uprobe *tu, struct trace_event_file *file) |
f3f096cf | 985 | { |
14577c39 | 986 | if (!trace_probe_is_enabled(&tu->tp)) |
f3f096cf SD |
987 | return; |
988 | ||
70ed91c6 | 989 | if (file) { |
b5f935ee | 990 | if (trace_probe_remove_file(&tu->tp, file) < 0) |
70ed91c6 J |
991 | return; |
992 | ||
b5f935ee | 993 | if (trace_probe_is_enabled(&tu->tp)) |
70ed91c6 | 994 | return; |
b5f935ee | 995 | } else |
747774d6 | 996 | trace_probe_clear_flag(&tu->tp, TP_FLAG_PROFILE); |
70ed91c6 | 997 | |
736288ba ON |
998 | WARN_ON(!uprobe_filter_is_empty(&tu->filter)); |
999 | ||
a932b738 | 1000 | uprobe_unregister(tu->inode, tu->offset, &tu->consumer); |
0c92c7a3 | 1001 | tu->inode = NULL; |
dcad1a20 NK |
1002 | |
1003 | uprobe_buffer_disable(); | |
f3f096cf SD |
1004 | } |
1005 | ||
2425bcb9 | 1006 | static int uprobe_event_define_fields(struct trace_event_call *event_call) |
f3f096cf | 1007 | { |
eeb07b06 | 1008 | int ret, size; |
f3f096cf | 1009 | struct uprobe_trace_entry_head field; |
457d1772 | 1010 | struct trace_uprobe *tu = event_call->data; |
f3f096cf | 1011 | |
4d1298e2 ON |
1012 | if (is_ret_probe(tu)) { |
1013 | DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_FUNC, 0); | |
1014 | DEFINE_FIELD(unsigned long, vaddr[1], FIELD_STRING_RETIP, 0); | |
1015 | size = SIZEOF_TRACE_ENTRY(true); | |
1016 | } else { | |
1017 | DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0); | |
1018 | size = SIZEOF_TRACE_ENTRY(false); | |
1019 | } | |
f3f096cf | 1020 | |
eeb07b06 | 1021 | return traceprobe_define_arg_fields(event_call, size, &tu->tp); |
f3f096cf SD |
1022 | } |
1023 | ||
f3f096cf | 1024 | #ifdef CONFIG_PERF_EVENTS |
31ba3348 ON |
1025 | static bool |
1026 | __uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm) | |
1027 | { | |
1028 | struct perf_event *event; | |
1029 | ||
1030 | if (filter->nr_systemwide) | |
1031 | return true; | |
1032 | ||
1033 | list_for_each_entry(event, &filter->perf_events, hw.tp_list) { | |
50f16a8b | 1034 | if (event->hw.target->mm == mm) |
31ba3348 ON |
1035 | return true; |
1036 | } | |
1037 | ||
1038 | return false; | |
1039 | } | |
1040 | ||
b2fe8ba6 ON |
1041 | static inline bool |
1042 | uprobe_filter_event(struct trace_uprobe *tu, struct perf_event *event) | |
1043 | { | |
50f16a8b | 1044 | return __uprobe_perf_filter(&tu->filter, event->hw.target->mm); |
b2fe8ba6 ON |
1045 | } |
1046 | ||
ce5f36a5 | 1047 | static int uprobe_perf_close(struct trace_uprobe *tu, struct perf_event *event) |
736288ba | 1048 | { |
b2fe8ba6 ON |
1049 | bool done; |
1050 | ||
736288ba | 1051 | write_lock(&tu->filter.rwlock); |
50f16a8b | 1052 | if (event->hw.target) { |
ce5f36a5 | 1053 | list_del(&event->hw.tp_list); |
b2fe8ba6 | 1054 | done = tu->filter.nr_systemwide || |
50f16a8b | 1055 | (event->hw.target->flags & PF_EXITING) || |
b2fe8ba6 | 1056 | uprobe_filter_event(tu, event); |
b2fe8ba6 | 1057 | } else { |
ce5f36a5 | 1058 | tu->filter.nr_systemwide--; |
b2fe8ba6 | 1059 | done = tu->filter.nr_systemwide; |
b2fe8ba6 | 1060 | } |
736288ba ON |
1061 | write_unlock(&tu->filter.rwlock); |
1062 | ||
b2fe8ba6 | 1063 | if (!done) |
927d6874 | 1064 | return uprobe_apply(tu->inode, tu->offset, &tu->consumer, false); |
31ba3348 | 1065 | |
736288ba ON |
1066 | return 0; |
1067 | } | |
1068 | ||
ce5f36a5 | 1069 | static int uprobe_perf_open(struct trace_uprobe *tu, struct perf_event *event) |
736288ba | 1070 | { |
b2fe8ba6 | 1071 | bool done; |
927d6874 | 1072 | int err; |
b2fe8ba6 | 1073 | |
736288ba | 1074 | write_lock(&tu->filter.rwlock); |
50f16a8b | 1075 | if (event->hw.target) { |
ce5f36a5 ON |
1076 | /* |
1077 | * event->parent != NULL means copy_process(), we can avoid | |
1078 | * uprobe_apply(). current->mm must be probed and we can rely | |
1079 | * on dup_mmap() which preserves the already installed bp's. | |
1080 | * | |
1081 | * attr.enable_on_exec means that exec/mmap will install the | |
1082 | * breakpoints we need. | |
1083 | */ | |
b2fe8ba6 | 1084 | done = tu->filter.nr_systemwide || |
ce5f36a5 | 1085 | event->parent || event->attr.enable_on_exec || |
b2fe8ba6 | 1086 | uprobe_filter_event(tu, event); |
ce5f36a5 | 1087 | list_add(&event->hw.tp_list, &tu->filter.perf_events); |
b2fe8ba6 | 1088 | } else { |
b2fe8ba6 | 1089 | done = tu->filter.nr_systemwide; |
ce5f36a5 | 1090 | tu->filter.nr_systemwide++; |
b2fe8ba6 | 1091 | } |
736288ba ON |
1092 | write_unlock(&tu->filter.rwlock); |
1093 | ||
927d6874 ON |
1094 | err = 0; |
1095 | if (!done) { | |
1096 | err = uprobe_apply(tu->inode, tu->offset, &tu->consumer, true); | |
1097 | if (err) | |
1098 | uprobe_perf_close(tu, event); | |
1099 | } | |
1100 | return err; | |
736288ba ON |
1101 | } |
1102 | ||
31ba3348 ON |
1103 | static bool uprobe_perf_filter(struct uprobe_consumer *uc, |
1104 | enum uprobe_filter_ctx ctx, struct mm_struct *mm) | |
1105 | { | |
1106 | struct trace_uprobe *tu; | |
1107 | int ret; | |
1108 | ||
1109 | tu = container_of(uc, struct trace_uprobe, consumer); | |
1110 | read_lock(&tu->filter.rwlock); | |
1111 | ret = __uprobe_perf_filter(&tu->filter, mm); | |
1112 | read_unlock(&tu->filter.rwlock); | |
1113 | ||
1114 | return ret; | |
1115 | } | |
1116 | ||
a43b9704 | 1117 | static void __uprobe_perf_func(struct trace_uprobe *tu, |
dd9fa555 NK |
1118 | unsigned long func, struct pt_regs *regs, |
1119 | struct uprobe_cpu_buffer *ucb, int dsize) | |
f3f096cf | 1120 | { |
e3dc9f89 | 1121 | struct trace_event_call *call = trace_probe_event_call(&tu->tp); |
f3f096cf SD |
1122 | struct uprobe_trace_entry_head *entry; |
1123 | struct hlist_head *head; | |
457d1772 | 1124 | void *data; |
dd9fa555 | 1125 | int size, esize; |
dcad1a20 NK |
1126 | int rctx; |
1127 | ||
e87c6bc3 | 1128 | if (bpf_prog_array_valid(call) && !trace_call_bpf(call, regs)) |
04a22fae WN |
1129 | return; |
1130 | ||
dcad1a20 | 1131 | esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); |
f3f096cf | 1132 | |
dcad1a20 NK |
1133 | size = esize + tu->tp.size + dsize; |
1134 | size = ALIGN(size + sizeof(u32), sizeof(u64)) - sizeof(u32); | |
1135 | if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough")) | |
1136 | return; | |
1137 | ||
f3f096cf | 1138 | preempt_disable(); |
515619f2 ON |
1139 | head = this_cpu_ptr(call->perf_events); |
1140 | if (hlist_empty(head)) | |
1141 | goto out; | |
1142 | ||
1e1dcd93 | 1143 | entry = perf_trace_buf_alloc(size, NULL, &rctx); |
f3f096cf SD |
1144 | if (!entry) |
1145 | goto out; | |
1146 | ||
393a736c ON |
1147 | if (is_ret_probe(tu)) { |
1148 | entry->vaddr[0] = func; | |
32520b2c | 1149 | entry->vaddr[1] = instruction_pointer(regs); |
393a736c ON |
1150 | data = DATAOF_TRACE_ENTRY(entry, true); |
1151 | } else { | |
32520b2c | 1152 | entry->vaddr[0] = instruction_pointer(regs); |
393a736c ON |
1153 | data = DATAOF_TRACE_ENTRY(entry, false); |
1154 | } | |
1155 | ||
dcad1a20 NK |
1156 | memcpy(data, ucb->buf, tu->tp.size + dsize); |
1157 | ||
1158 | if (size - esize > tu->tp.size + dsize) { | |
1159 | int len = tu->tp.size + dsize; | |
14577c39 | 1160 | |
dcad1a20 | 1161 | memset(data + len, 0, size - esize - len); |
14577c39 | 1162 | } |
f3f096cf | 1163 | |
1e1dcd93 | 1164 | perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, |
8fd0fbbe | 1165 | head, NULL); |
f3f096cf SD |
1166 | out: |
1167 | preempt_enable(); | |
a51cc604 ON |
1168 | } |
1169 | ||
1170 | /* uprobe profile handler */ | |
dd9fa555 NK |
1171 | static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs, |
1172 | struct uprobe_cpu_buffer *ucb, int dsize) | |
a51cc604 ON |
1173 | { |
1174 | if (!uprobe_perf_filter(&tu->consumer, 0, current->mm)) | |
1175 | return UPROBE_HANDLER_REMOVE; | |
1176 | ||
393a736c | 1177 | if (!is_ret_probe(tu)) |
dd9fa555 | 1178 | __uprobe_perf_func(tu, 0, regs, ucb, dsize); |
f42d24a1 | 1179 | return 0; |
f3f096cf | 1180 | } |
c1ae5c75 ON |
1181 | |
1182 | static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func, | |
dd9fa555 NK |
1183 | struct pt_regs *regs, |
1184 | struct uprobe_cpu_buffer *ucb, int dsize) | |
c1ae5c75 | 1185 | { |
dd9fa555 | 1186 | __uprobe_perf_func(tu, func, regs, ucb, dsize); |
c1ae5c75 | 1187 | } |
41bdc4b4 YS |
1188 | |
1189 | int bpf_get_uprobe_info(const struct perf_event *event, u32 *fd_type, | |
1190 | const char **filename, u64 *probe_offset, | |
1191 | bool perf_type_tracepoint) | |
1192 | { | |
1193 | const char *pevent = trace_event_name(event->tp_event); | |
1194 | const char *group = event->tp_event->class->system; | |
1195 | struct trace_uprobe *tu; | |
1196 | ||
1197 | if (perf_type_tracepoint) | |
1198 | tu = find_probe_event(pevent, group); | |
1199 | else | |
1200 | tu = event->tp_event->data; | |
1201 | if (!tu) | |
1202 | return -EINVAL; | |
1203 | ||
1204 | *fd_type = is_ret_probe(tu) ? BPF_FD_TYPE_URETPROBE | |
1205 | : BPF_FD_TYPE_UPROBE; | |
1206 | *filename = tu->filename; | |
1207 | *probe_offset = tu->offset; | |
1208 | return 0; | |
1209 | } | |
f3f096cf SD |
1210 | #endif /* CONFIG_PERF_EVENTS */ |
1211 | ||
70ed91c6 | 1212 | static int |
2425bcb9 | 1213 | trace_uprobe_register(struct trace_event_call *event, enum trace_reg type, |
70ed91c6 | 1214 | void *data) |
f3f096cf | 1215 | { |
457d1772 | 1216 | struct trace_uprobe *tu = event->data; |
7f1d2f82 | 1217 | struct trace_event_file *file = data; |
f3f096cf SD |
1218 | |
1219 | switch (type) { | |
1220 | case TRACE_REG_REGISTER: | |
70ed91c6 | 1221 | return probe_event_enable(tu, file, NULL); |
f3f096cf SD |
1222 | |
1223 | case TRACE_REG_UNREGISTER: | |
70ed91c6 | 1224 | probe_event_disable(tu, file); |
f3f096cf SD |
1225 | return 0; |
1226 | ||
1227 | #ifdef CONFIG_PERF_EVENTS | |
1228 | case TRACE_REG_PERF_REGISTER: | |
70ed91c6 | 1229 | return probe_event_enable(tu, NULL, uprobe_perf_filter); |
f3f096cf SD |
1230 | |
1231 | case TRACE_REG_PERF_UNREGISTER: | |
70ed91c6 | 1232 | probe_event_disable(tu, NULL); |
f3f096cf | 1233 | return 0; |
736288ba ON |
1234 | |
1235 | case TRACE_REG_PERF_OPEN: | |
1236 | return uprobe_perf_open(tu, data); | |
1237 | ||
1238 | case TRACE_REG_PERF_CLOSE: | |
1239 | return uprobe_perf_close(tu, data); | |
1240 | ||
f3f096cf SD |
1241 | #endif |
1242 | default: | |
1243 | return 0; | |
1244 | } | |
1245 | return 0; | |
1246 | } | |
1247 | ||
1248 | static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs) | |
1249 | { | |
f3f096cf | 1250 | struct trace_uprobe *tu; |
b7e0bf34 | 1251 | struct uprobe_dispatch_data udd; |
dd9fa555 NK |
1252 | struct uprobe_cpu_buffer *ucb; |
1253 | int dsize, esize; | |
f42d24a1 | 1254 | int ret = 0; |
f3f096cf | 1255 | |
dd9fa555 | 1256 | |
a932b738 | 1257 | tu = container_of(con, struct trace_uprobe, consumer); |
1b47aefd | 1258 | tu->nhit++; |
f3f096cf | 1259 | |
b7e0bf34 NK |
1260 | udd.tu = tu; |
1261 | udd.bp_addr = instruction_pointer(regs); | |
1262 | ||
1263 | current->utask->vaddr = (unsigned long) &udd; | |
1264 | ||
dd9fa555 NK |
1265 | if (WARN_ON_ONCE(!uprobe_cpu_buffer)) |
1266 | return 0; | |
1267 | ||
1268 | dsize = __get_data_size(&tu->tp, regs); | |
1269 | esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); | |
1270 | ||
1271 | ucb = uprobe_buffer_get(); | |
9178412d | 1272 | store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize); |
dd9fa555 | 1273 | |
747774d6 | 1274 | if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE)) |
dd9fa555 | 1275 | ret |= uprobe_trace_func(tu, regs, ucb, dsize); |
f3f096cf SD |
1276 | |
1277 | #ifdef CONFIG_PERF_EVENTS | |
747774d6 | 1278 | if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE)) |
dd9fa555 | 1279 | ret |= uprobe_perf_func(tu, regs, ucb, dsize); |
f3f096cf | 1280 | #endif |
dd9fa555 | 1281 | uprobe_buffer_put(ucb); |
f42d24a1 | 1282 | return ret; |
f3f096cf SD |
1283 | } |
1284 | ||
c1ae5c75 ON |
1285 | static int uretprobe_dispatcher(struct uprobe_consumer *con, |
1286 | unsigned long func, struct pt_regs *regs) | |
1287 | { | |
1288 | struct trace_uprobe *tu; | |
b7e0bf34 | 1289 | struct uprobe_dispatch_data udd; |
dd9fa555 NK |
1290 | struct uprobe_cpu_buffer *ucb; |
1291 | int dsize, esize; | |
c1ae5c75 ON |
1292 | |
1293 | tu = container_of(con, struct trace_uprobe, consumer); | |
1294 | ||
b7e0bf34 NK |
1295 | udd.tu = tu; |
1296 | udd.bp_addr = func; | |
1297 | ||
1298 | current->utask->vaddr = (unsigned long) &udd; | |
1299 | ||
dd9fa555 NK |
1300 | if (WARN_ON_ONCE(!uprobe_cpu_buffer)) |
1301 | return 0; | |
1302 | ||
1303 | dsize = __get_data_size(&tu->tp, regs); | |
1304 | esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); | |
1305 | ||
1306 | ucb = uprobe_buffer_get(); | |
9178412d | 1307 | store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize); |
dd9fa555 | 1308 | |
747774d6 | 1309 | if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE)) |
dd9fa555 | 1310 | uretprobe_trace_func(tu, func, regs, ucb, dsize); |
c1ae5c75 ON |
1311 | |
1312 | #ifdef CONFIG_PERF_EVENTS | |
747774d6 | 1313 | if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE)) |
dd9fa555 | 1314 | uretprobe_perf_func(tu, func, regs, ucb, dsize); |
c1ae5c75 | 1315 | #endif |
dd9fa555 | 1316 | uprobe_buffer_put(ucb); |
c1ae5c75 ON |
1317 | return 0; |
1318 | } | |
1319 | ||
f3f096cf SD |
1320 | static struct trace_event_functions uprobe_funcs = { |
1321 | .trace = print_uprobe_event | |
1322 | }; | |
1323 | ||
e3dc9f89 | 1324 | static inline void init_trace_event_call(struct trace_uprobe *tu) |
f3f096cf | 1325 | { |
e3dc9f89 MH |
1326 | struct trace_event_call *call = trace_probe_event_call(&tu->tp); |
1327 | ||
f3f096cf SD |
1328 | call->event.funcs = &uprobe_funcs; |
1329 | call->class->define_fields = uprobe_event_define_fields; | |
1330 | ||
9fd2e48b | 1331 | call->flags = TRACE_EVENT_FL_UPROBE | TRACE_EVENT_FL_CAP_ANY; |
33ea4b24 SL |
1332 | call->class->reg = trace_uprobe_register; |
1333 | call->data = tu; | |
1334 | } | |
1335 | ||
1336 | static int register_uprobe_event(struct trace_uprobe *tu) | |
1337 | { | |
e3dc9f89 | 1338 | init_trace_event_call(tu); |
f3f096cf | 1339 | |
46e5376d | 1340 | return trace_probe_register_event_call(&tu->tp); |
f3f096cf SD |
1341 | } |
1342 | ||
c6c2401d | 1343 | static int unregister_uprobe_event(struct trace_uprobe *tu) |
f3f096cf | 1344 | { |
46e5376d | 1345 | return trace_probe_unregister_event_call(&tu->tp); |
f3f096cf SD |
1346 | } |
1347 | ||
33ea4b24 SL |
1348 | #ifdef CONFIG_PERF_EVENTS |
1349 | struct trace_event_call * | |
a6ca88b2 SL |
1350 | create_local_trace_uprobe(char *name, unsigned long offs, |
1351 | unsigned long ref_ctr_offset, bool is_return) | |
33ea4b24 SL |
1352 | { |
1353 | struct trace_uprobe *tu; | |
33ea4b24 SL |
1354 | struct path path; |
1355 | int ret; | |
1356 | ||
1357 | ret = kern_path(name, LOOKUP_FOLLOW, &path); | |
1358 | if (ret) | |
1359 | return ERR_PTR(ret); | |
1360 | ||
0c92c7a3 SL |
1361 | if (!d_is_reg(path.dentry)) { |
1362 | path_put(&path); | |
33ea4b24 SL |
1363 | return ERR_PTR(-EINVAL); |
1364 | } | |
1365 | ||
1366 | /* | |
0597c49c | 1367 | * local trace_kprobes are not added to dyn_event, so they are never |
33ea4b24 SL |
1368 | * searched in find_trace_kprobe(). Therefore, there is no concern of |
1369 | * duplicated name "DUMMY_EVENT" here. | |
1370 | */ | |
1371 | tu = alloc_trace_uprobe(UPROBE_EVENT_SYSTEM, "DUMMY_EVENT", 0, | |
1372 | is_return); | |
1373 | ||
1374 | if (IS_ERR(tu)) { | |
1375 | pr_info("Failed to allocate trace_uprobe.(%d)\n", | |
1376 | (int)PTR_ERR(tu)); | |
0c92c7a3 | 1377 | path_put(&path); |
33ea4b24 SL |
1378 | return ERR_CAST(tu); |
1379 | } | |
1380 | ||
1381 | tu->offset = offs; | |
0c92c7a3 | 1382 | tu->path = path; |
a6ca88b2 | 1383 | tu->ref_ctr_offset = ref_ctr_offset; |
33ea4b24 | 1384 | tu->filename = kstrdup(name, GFP_KERNEL); |
e3dc9f89 | 1385 | init_trace_event_call(tu); |
33ea4b24 | 1386 | |
0a46c854 | 1387 | if (traceprobe_set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0) { |
33ea4b24 SL |
1388 | ret = -ENOMEM; |
1389 | goto error; | |
1390 | } | |
1391 | ||
e3dc9f89 | 1392 | return trace_probe_event_call(&tu->tp); |
33ea4b24 SL |
1393 | error: |
1394 | free_trace_uprobe(tu); | |
1395 | return ERR_PTR(ret); | |
1396 | } | |
1397 | ||
1398 | void destroy_local_trace_uprobe(struct trace_event_call *event_call) | |
1399 | { | |
1400 | struct trace_uprobe *tu; | |
1401 | ||
1402 | tu = container_of(event_call, struct trace_uprobe, tp.call); | |
1403 | ||
33ea4b24 SL |
1404 | free_trace_uprobe(tu); |
1405 | } | |
1406 | #endif /* CONFIG_PERF_EVENTS */ | |
1407 | ||
f3f096cf SD |
1408 | /* Make a trace interface for controling probe points */ |
1409 | static __init int init_uprobe_trace(void) | |
1410 | { | |
1411 | struct dentry *d_tracer; | |
0597c49c MH |
1412 | int ret; |
1413 | ||
1414 | ret = dyn_event_register(&trace_uprobe_ops); | |
1415 | if (ret) | |
1416 | return ret; | |
f3f096cf SD |
1417 | |
1418 | d_tracer = tracing_init_dentry(); | |
14a5ae40 | 1419 | if (IS_ERR(d_tracer)) |
f3f096cf SD |
1420 | return 0; |
1421 | ||
1422 | trace_create_file("uprobe_events", 0644, d_tracer, | |
1423 | NULL, &uprobe_events_ops); | |
1424 | /* Profile interface */ | |
1425 | trace_create_file("uprobe_profile", 0444, d_tracer, | |
1426 | NULL, &uprobe_profile_ops); | |
1427 | return 0; | |
1428 | } | |
1429 | ||
1430 | fs_initcall(init_uprobe_trace); |