Commit | Line | Data |
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8ab83f56 SD |
1 | /* |
2 | * Common code for probe-based Dynamic events. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License version 2 as | |
6 | * published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
11 | * GNU General Public License for more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public License | |
14 | * along with this program; if not, write to the Free Software | |
15 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
16 | * | |
17 | * This code was copied from kernel/trace/trace_kprobe.c written by | |
18 | * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> | |
19 | * | |
20 | * Updates to make this generic: | |
21 | * Copyright (C) IBM Corporation, 2010-2011 | |
22 | * Author: Srikar Dronamraju | |
23 | */ | |
72576341 | 24 | #define pr_fmt(fmt) "trace_probe: " fmt |
8ab83f56 SD |
25 | |
26 | #include "trace_probe.h" | |
27 | ||
28 | const char *reserved_field_names[] = { | |
29 | "common_type", | |
30 | "common_flags", | |
31 | "common_preempt_count", | |
32 | "common_pid", | |
33 | "common_tgid", | |
34 | FIELD_STRING_IP, | |
35 | FIELD_STRING_RETIP, | |
36 | FIELD_STRING_FUNC, | |
37 | }; | |
38 | ||
8ab83f56 | 39 | /* Printing in basic type function template */ |
17ce3dc7 MH |
40 | #define DEFINE_BASIC_PRINT_TYPE_FUNC(tname, type, fmt) \ |
41 | int PRINT_TYPE_FUNC_NAME(tname)(struct trace_seq *s, const char *name, \ | |
3da0f180 | 42 | void *data, void *ent) \ |
8ab83f56 | 43 | { \ |
d2b0191a SRRH |
44 | trace_seq_printf(s, " %s=" fmt, name, *(type *)data); \ |
45 | return !trace_seq_has_overflowed(s); \ | |
8ab83f56 | 46 | } \ |
17ce3dc7 MH |
47 | const char PRINT_TYPE_FMT_NAME(tname)[] = fmt; \ |
48 | NOKPROBE_SYMBOL(PRINT_TYPE_FUNC_NAME(tname)); | |
8ab83f56 | 49 | |
bdca79c2 MH |
50 | DEFINE_BASIC_PRINT_TYPE_FUNC(u8, u8, "%u") |
51 | DEFINE_BASIC_PRINT_TYPE_FUNC(u16, u16, "%u") | |
52 | DEFINE_BASIC_PRINT_TYPE_FUNC(u32, u32, "%u") | |
53 | DEFINE_BASIC_PRINT_TYPE_FUNC(u64, u64, "%Lu") | |
17ce3dc7 MH |
54 | DEFINE_BASIC_PRINT_TYPE_FUNC(s8, s8, "%d") |
55 | DEFINE_BASIC_PRINT_TYPE_FUNC(s16, s16, "%d") | |
56 | DEFINE_BASIC_PRINT_TYPE_FUNC(s32, s32, "%d") | |
57 | DEFINE_BASIC_PRINT_TYPE_FUNC(s64, s64, "%Ld") | |
58 | DEFINE_BASIC_PRINT_TYPE_FUNC(x8, u8, "0x%x") | |
59 | DEFINE_BASIC_PRINT_TYPE_FUNC(x16, u16, "0x%x") | |
60 | DEFINE_BASIC_PRINT_TYPE_FUNC(x32, u32, "0x%x") | |
61 | DEFINE_BASIC_PRINT_TYPE_FUNC(x64, u64, "0x%Lx") | |
8ab83f56 | 62 | |
8ab83f56 | 63 | /* Print type function for string type */ |
3da0f180 MH |
64 | int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, const char *name, |
65 | void *data, void *ent) | |
8ab83f56 SD |
66 | { |
67 | int len = *(u32 *)data >> 16; | |
68 | ||
69 | if (!len) | |
d2b0191a | 70 | trace_seq_printf(s, " %s=(fault)", name); |
8ab83f56 | 71 | else |
d2b0191a SRRH |
72 | trace_seq_printf(s, " %s=\"%s\"", name, |
73 | (const char *)get_loc_data(data, ent)); | |
74 | return !trace_seq_has_overflowed(s); | |
8ab83f56 | 75 | } |
3da0f180 | 76 | NOKPROBE_SYMBOL(PRINT_TYPE_FUNC_NAME(string)); |
8ab83f56 | 77 | |
b26c74e1 | 78 | const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\""; |
8ab83f56 | 79 | |
8ab83f56 SD |
80 | #define CHECK_FETCH_FUNCS(method, fn) \ |
81 | (((FETCH_FUNC_NAME(method, u8) == fn) || \ | |
82 | (FETCH_FUNC_NAME(method, u16) == fn) || \ | |
83 | (FETCH_FUNC_NAME(method, u32) == fn) || \ | |
84 | (FETCH_FUNC_NAME(method, u64) == fn) || \ | |
85 | (FETCH_FUNC_NAME(method, string) == fn) || \ | |
86 | (FETCH_FUNC_NAME(method, string_size) == fn)) \ | |
87 | && (fn != NULL)) | |
88 | ||
89 | /* Data fetch function templates */ | |
90 | #define DEFINE_FETCH_reg(type) \ | |
3da0f180 | 91 | void FETCH_FUNC_NAME(reg, type)(struct pt_regs *regs, void *offset, void *dest) \ |
8ab83f56 SD |
92 | { \ |
93 | *(type *)dest = (type)regs_get_register(regs, \ | |
94 | (unsigned int)((unsigned long)offset)); \ | |
3da0f180 MH |
95 | } \ |
96 | NOKPROBE_SYMBOL(FETCH_FUNC_NAME(reg, type)); | |
8ab83f56 SD |
97 | DEFINE_BASIC_FETCH_FUNCS(reg) |
98 | /* No string on the register */ | |
99 | #define fetch_reg_string NULL | |
100 | #define fetch_reg_string_size NULL | |
101 | ||
8ab83f56 | 102 | #define DEFINE_FETCH_retval(type) \ |
3da0f180 MH |
103 | void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs, \ |
104 | void *dummy, void *dest) \ | |
8ab83f56 SD |
105 | { \ |
106 | *(type *)dest = (type)regs_return_value(regs); \ | |
3da0f180 MH |
107 | } \ |
108 | NOKPROBE_SYMBOL(FETCH_FUNC_NAME(retval, type)); | |
8ab83f56 SD |
109 | DEFINE_BASIC_FETCH_FUNCS(retval) |
110 | /* No string on the retval */ | |
111 | #define fetch_retval_string NULL | |
112 | #define fetch_retval_string_size NULL | |
113 | ||
8ab83f56 SD |
114 | /* Dereference memory access function */ |
115 | struct deref_fetch_param { | |
116 | struct fetch_param orig; | |
117 | long offset; | |
3925f4a5 HL |
118 | fetch_func_t fetch; |
119 | fetch_func_t fetch_size; | |
8ab83f56 SD |
120 | }; |
121 | ||
122 | #define DEFINE_FETCH_deref(type) \ | |
3da0f180 MH |
123 | void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs, \ |
124 | void *data, void *dest) \ | |
8ab83f56 SD |
125 | { \ |
126 | struct deref_fetch_param *dprm = data; \ | |
127 | unsigned long addr; \ | |
128 | call_fetch(&dprm->orig, regs, &addr); \ | |
129 | if (addr) { \ | |
130 | addr += dprm->offset; \ | |
3925f4a5 | 131 | dprm->fetch(regs, (void *)addr, dest); \ |
8ab83f56 SD |
132 | } else \ |
133 | *(type *)dest = 0; \ | |
3da0f180 MH |
134 | } \ |
135 | NOKPROBE_SYMBOL(FETCH_FUNC_NAME(deref, type)); | |
8ab83f56 SD |
136 | DEFINE_BASIC_FETCH_FUNCS(deref) |
137 | DEFINE_FETCH_deref(string) | |
3925f4a5 | 138 | |
3da0f180 MH |
139 | void FETCH_FUNC_NAME(deref, string_size)(struct pt_regs *regs, |
140 | void *data, void *dest) | |
3925f4a5 HL |
141 | { |
142 | struct deref_fetch_param *dprm = data; | |
143 | unsigned long addr; | |
144 | ||
145 | call_fetch(&dprm->orig, regs, &addr); | |
146 | if (addr && dprm->fetch_size) { | |
147 | addr += dprm->offset; | |
148 | dprm->fetch_size(regs, (void *)addr, dest); | |
149 | } else | |
150 | *(string_size *)dest = 0; | |
151 | } | |
3da0f180 | 152 | NOKPROBE_SYMBOL(FETCH_FUNC_NAME(deref, string_size)); |
8ab83f56 | 153 | |
3da0f180 | 154 | static void update_deref_fetch_param(struct deref_fetch_param *data) |
8ab83f56 SD |
155 | { |
156 | if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) | |
157 | update_deref_fetch_param(data->orig.data); | |
158 | else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) | |
159 | update_symbol_cache(data->orig.data); | |
160 | } | |
3da0f180 | 161 | NOKPROBE_SYMBOL(update_deref_fetch_param); |
8ab83f56 | 162 | |
3da0f180 | 163 | static void free_deref_fetch_param(struct deref_fetch_param *data) |
8ab83f56 SD |
164 | { |
165 | if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) | |
166 | free_deref_fetch_param(data->orig.data); | |
167 | else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) | |
168 | free_symbol_cache(data->orig.data); | |
169 | kfree(data); | |
170 | } | |
3da0f180 | 171 | NOKPROBE_SYMBOL(free_deref_fetch_param); |
8ab83f56 SD |
172 | |
173 | /* Bitfield fetch function */ | |
174 | struct bitfield_fetch_param { | |
175 | struct fetch_param orig; | |
176 | unsigned char hi_shift; | |
177 | unsigned char low_shift; | |
178 | }; | |
179 | ||
180 | #define DEFINE_FETCH_bitfield(type) \ | |
3da0f180 MH |
181 | void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs, \ |
182 | void *data, void *dest) \ | |
8ab83f56 SD |
183 | { \ |
184 | struct bitfield_fetch_param *bprm = data; \ | |
185 | type buf = 0; \ | |
186 | call_fetch(&bprm->orig, regs, &buf); \ | |
187 | if (buf) { \ | |
188 | buf <<= bprm->hi_shift; \ | |
189 | buf >>= bprm->low_shift; \ | |
190 | } \ | |
191 | *(type *)dest = buf; \ | |
3da0f180 MH |
192 | } \ |
193 | NOKPROBE_SYMBOL(FETCH_FUNC_NAME(bitfield, type)); | |
8ab83f56 SD |
194 | DEFINE_BASIC_FETCH_FUNCS(bitfield) |
195 | #define fetch_bitfield_string NULL | |
196 | #define fetch_bitfield_string_size NULL | |
197 | ||
fbc1963d | 198 | static void |
8ab83f56 SD |
199 | update_bitfield_fetch_param(struct bitfield_fetch_param *data) |
200 | { | |
201 | /* | |
202 | * Don't check the bitfield itself, because this must be the | |
203 | * last fetch function. | |
204 | */ | |
205 | if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) | |
206 | update_deref_fetch_param(data->orig.data); | |
207 | else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) | |
208 | update_symbol_cache(data->orig.data); | |
209 | } | |
210 | ||
fbc1963d | 211 | static void |
8ab83f56 SD |
212 | free_bitfield_fetch_param(struct bitfield_fetch_param *data) |
213 | { | |
214 | /* | |
215 | * Don't check the bitfield itself, because this must be the | |
216 | * last fetch function. | |
217 | */ | |
218 | if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) | |
219 | free_deref_fetch_param(data->orig.data); | |
220 | else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) | |
221 | free_symbol_cache(data->orig.data); | |
222 | ||
223 | kfree(data); | |
224 | } | |
225 | ||
35abb67d OS |
226 | void FETCH_FUNC_NAME(comm, string)(struct pt_regs *regs, |
227 | void *data, void *dest) | |
228 | { | |
229 | int maxlen = get_rloc_len(*(u32 *)dest); | |
230 | u8 *dst = get_rloc_data(dest); | |
231 | long ret; | |
232 | ||
233 | if (!maxlen) | |
234 | return; | |
235 | ||
236 | ret = strlcpy(dst, current->comm, maxlen); | |
237 | *(u32 *)dest = make_data_rloc(ret, get_rloc_offs(*(u32 *)dest)); | |
238 | } | |
239 | NOKPROBE_SYMBOL(FETCH_FUNC_NAME(comm, string)); | |
240 | ||
241 | void FETCH_FUNC_NAME(comm, string_size)(struct pt_regs *regs, | |
242 | void *data, void *dest) | |
243 | { | |
244 | *(u32 *)dest = strlen(current->comm) + 1; | |
245 | } | |
246 | NOKPROBE_SYMBOL(FETCH_FUNC_NAME(comm, string_size)); | |
247 | ||
34fee3a1 NK |
248 | static const struct fetch_type *find_fetch_type(const char *type, |
249 | const struct fetch_type *ftbl) | |
8ab83f56 SD |
250 | { |
251 | int i; | |
252 | ||
253 | if (!type) | |
254 | type = DEFAULT_FETCH_TYPE_STR; | |
255 | ||
256 | /* Special case: bitfield */ | |
257 | if (*type == 'b') { | |
258 | unsigned long bs; | |
259 | ||
260 | type = strchr(type, '/'); | |
261 | if (!type) | |
262 | goto fail; | |
263 | ||
264 | type++; | |
bcd83ea6 | 265 | if (kstrtoul(type, 0, &bs)) |
8ab83f56 SD |
266 | goto fail; |
267 | ||
268 | switch (bs) { | |
269 | case 8: | |
34fee3a1 | 270 | return find_fetch_type("u8", ftbl); |
8ab83f56 | 271 | case 16: |
34fee3a1 | 272 | return find_fetch_type("u16", ftbl); |
8ab83f56 | 273 | case 32: |
34fee3a1 | 274 | return find_fetch_type("u32", ftbl); |
8ab83f56 | 275 | case 64: |
34fee3a1 | 276 | return find_fetch_type("u64", ftbl); |
8ab83f56 SD |
277 | default: |
278 | goto fail; | |
279 | } | |
280 | } | |
281 | ||
34fee3a1 NK |
282 | for (i = 0; ftbl[i].name; i++) { |
283 | if (strcmp(type, ftbl[i].name) == 0) | |
284 | return &ftbl[i]; | |
285 | } | |
8ab83f56 SD |
286 | |
287 | fail: | |
288 | return NULL; | |
289 | } | |
290 | ||
291 | /* Special function : only accept unsigned long */ | |
3da0f180 | 292 | static void fetch_kernel_stack_address(struct pt_regs *regs, void *dummy, void *dest) |
8ab83f56 SD |
293 | { |
294 | *(unsigned long *)dest = kernel_stack_pointer(regs); | |
295 | } | |
3da0f180 | 296 | NOKPROBE_SYMBOL(fetch_kernel_stack_address); |
8ab83f56 | 297 | |
3da0f180 | 298 | static void fetch_user_stack_address(struct pt_regs *regs, void *dummy, void *dest) |
b079d374 NK |
299 | { |
300 | *(unsigned long *)dest = user_stack_pointer(regs); | |
301 | } | |
3da0f180 | 302 | NOKPROBE_SYMBOL(fetch_user_stack_address); |
b079d374 | 303 | |
8ab83f56 | 304 | static fetch_func_t get_fetch_size_function(const struct fetch_type *type, |
34fee3a1 NK |
305 | fetch_func_t orig_fn, |
306 | const struct fetch_type *ftbl) | |
8ab83f56 SD |
307 | { |
308 | int i; | |
309 | ||
34fee3a1 | 310 | if (type != &ftbl[FETCH_TYPE_STRING]) |
8ab83f56 SD |
311 | return NULL; /* Only string type needs size function */ |
312 | ||
313 | for (i = 0; i < FETCH_MTD_END; i++) | |
314 | if (type->fetch[i] == orig_fn) | |
34fee3a1 | 315 | return ftbl[FETCH_TYPE_STRSIZE].fetch[i]; |
8ab83f56 SD |
316 | |
317 | WARN_ON(1); /* This should not happen */ | |
318 | ||
319 | return NULL; | |
320 | } | |
321 | ||
322 | /* Split symbol and offset. */ | |
323 | int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset) | |
324 | { | |
325 | char *tmp; | |
326 | int ret; | |
327 | ||
328 | if (!offset) | |
329 | return -EINVAL; | |
330 | ||
331 | tmp = strchr(symbol, '+'); | |
332 | if (tmp) { | |
bcd83ea6 DW |
333 | /* skip sign because kstrtoul doesn't accept '+' */ |
334 | ret = kstrtoul(tmp + 1, 0, offset); | |
8ab83f56 SD |
335 | if (ret) |
336 | return ret; | |
337 | ||
338 | *tmp = '\0'; | |
339 | } else | |
340 | *offset = 0; | |
341 | ||
342 | return 0; | |
343 | } | |
344 | ||
345 | #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long)) | |
346 | ||
347 | static int parse_probe_vars(char *arg, const struct fetch_type *t, | |
b079d374 NK |
348 | struct fetch_param *f, bool is_return, |
349 | bool is_kprobe) | |
8ab83f56 SD |
350 | { |
351 | int ret = 0; | |
352 | unsigned long param; | |
353 | ||
354 | if (strcmp(arg, "retval") == 0) { | |
355 | if (is_return) | |
356 | f->fn = t->fetch[FETCH_MTD_retval]; | |
357 | else | |
358 | ret = -EINVAL; | |
359 | } else if (strncmp(arg, "stack", 5) == 0) { | |
360 | if (arg[5] == '\0') { | |
b079d374 NK |
361 | if (strcmp(t->name, DEFAULT_FETCH_TYPE_STR)) |
362 | return -EINVAL; | |
363 | ||
364 | if (is_kprobe) | |
365 | f->fn = fetch_kernel_stack_address; | |
8ab83f56 | 366 | else |
b079d374 | 367 | f->fn = fetch_user_stack_address; |
8ab83f56 | 368 | } else if (isdigit(arg[5])) { |
bcd83ea6 | 369 | ret = kstrtoul(arg + 5, 10, ¶m); |
b079d374 | 370 | if (ret || (is_kprobe && param > PARAM_MAX_STACK)) |
8ab83f56 SD |
371 | ret = -EINVAL; |
372 | else { | |
373 | f->fn = t->fetch[FETCH_MTD_stack]; | |
374 | f->data = (void *)param; | |
375 | } | |
376 | } else | |
377 | ret = -EINVAL; | |
35abb67d OS |
378 | } else if (strcmp(arg, "comm") == 0) { |
379 | if (strcmp(t->name, "string") != 0 && | |
380 | strcmp(t->name, "string_size") != 0) | |
381 | return -EINVAL; | |
382 | f->fn = t->fetch[FETCH_MTD_comm]; | |
8ab83f56 SD |
383 | } else |
384 | ret = -EINVAL; | |
385 | ||
386 | return ret; | |
387 | } | |
388 | ||
389 | /* Recursive argument parser */ | |
390 | static int parse_probe_arg(char *arg, const struct fetch_type *t, | |
d9a16d3a SR |
391 | struct fetch_param *f, bool is_return, bool is_kprobe, |
392 | const struct fetch_type *ftbl) | |
8ab83f56 SD |
393 | { |
394 | unsigned long param; | |
395 | long offset; | |
396 | char *tmp; | |
34fee3a1 | 397 | int ret = 0; |
8ab83f56 | 398 | |
8ab83f56 SD |
399 | switch (arg[0]) { |
400 | case '$': | |
b079d374 | 401 | ret = parse_probe_vars(arg + 1, t, f, is_return, is_kprobe); |
8ab83f56 SD |
402 | break; |
403 | ||
404 | case '%': /* named register */ | |
405 | ret = regs_query_register_offset(arg + 1); | |
406 | if (ret >= 0) { | |
407 | f->fn = t->fetch[FETCH_MTD_reg]; | |
408 | f->data = (void *)(unsigned long)ret; | |
409 | ret = 0; | |
410 | } | |
411 | break; | |
412 | ||
b7e0bf34 | 413 | case '@': /* memory, file-offset or symbol */ |
8ab83f56 | 414 | if (isdigit(arg[1])) { |
bcd83ea6 | 415 | ret = kstrtoul(arg + 1, 0, ¶m); |
8ab83f56 SD |
416 | if (ret) |
417 | break; | |
418 | ||
419 | f->fn = t->fetch[FETCH_MTD_memory]; | |
420 | f->data = (void *)param; | |
b7e0bf34 NK |
421 | } else if (arg[1] == '+') { |
422 | /* kprobes don't support file offsets */ | |
423 | if (is_kprobe) | |
424 | return -EINVAL; | |
425 | ||
426 | ret = kstrtol(arg + 2, 0, &offset); | |
427 | if (ret) | |
428 | break; | |
429 | ||
430 | f->fn = t->fetch[FETCH_MTD_file_offset]; | |
431 | f->data = (void *)offset; | |
8ab83f56 | 432 | } else { |
b079d374 NK |
433 | /* uprobes don't support symbols */ |
434 | if (!is_kprobe) | |
435 | return -EINVAL; | |
436 | ||
8ab83f56 SD |
437 | ret = traceprobe_split_symbol_offset(arg + 1, &offset); |
438 | if (ret) | |
439 | break; | |
440 | ||
441 | f->data = alloc_symbol_cache(arg + 1, offset); | |
442 | if (f->data) | |
443 | f->fn = t->fetch[FETCH_MTD_symbol]; | |
444 | } | |
445 | break; | |
446 | ||
447 | case '+': /* deref memory */ | |
bcd83ea6 | 448 | arg++; /* Skip '+', because kstrtol() rejects it. */ |
8ab83f56 SD |
449 | case '-': |
450 | tmp = strchr(arg, '('); | |
451 | if (!tmp) | |
452 | break; | |
453 | ||
454 | *tmp = '\0'; | |
bcd83ea6 | 455 | ret = kstrtol(arg, 0, &offset); |
8ab83f56 SD |
456 | |
457 | if (ret) | |
458 | break; | |
459 | ||
460 | arg = tmp + 1; | |
461 | tmp = strrchr(arg, ')'); | |
462 | ||
463 | if (tmp) { | |
464 | struct deref_fetch_param *dprm; | |
465 | const struct fetch_type *t2; | |
466 | ||
34fee3a1 | 467 | t2 = find_fetch_type(NULL, ftbl); |
8ab83f56 SD |
468 | *tmp = '\0'; |
469 | dprm = kzalloc(sizeof(struct deref_fetch_param), GFP_KERNEL); | |
470 | ||
471 | if (!dprm) | |
472 | return -ENOMEM; | |
473 | ||
474 | dprm->offset = offset; | |
3925f4a5 HL |
475 | dprm->fetch = t->fetch[FETCH_MTD_memory]; |
476 | dprm->fetch_size = get_fetch_size_function(t, | |
477 | dprm->fetch, ftbl); | |
f3f096cf | 478 | ret = parse_probe_arg(arg, t2, &dprm->orig, is_return, |
d9a16d3a | 479 | is_kprobe, ftbl); |
8ab83f56 SD |
480 | if (ret) |
481 | kfree(dprm); | |
482 | else { | |
483 | f->fn = t->fetch[FETCH_MTD_deref]; | |
484 | f->data = (void *)dprm; | |
485 | } | |
486 | } | |
487 | break; | |
488 | } | |
489 | if (!ret && !f->fn) { /* Parsed, but do not find fetch method */ | |
490 | pr_info("%s type has no corresponding fetch method.\n", t->name); | |
491 | ret = -EINVAL; | |
492 | } | |
493 | ||
494 | return ret; | |
495 | } | |
496 | ||
497 | #define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long)) | |
498 | ||
499 | /* Bitfield type needs to be parsed into a fetch function */ | |
500 | static int __parse_bitfield_probe_arg(const char *bf, | |
501 | const struct fetch_type *t, | |
502 | struct fetch_param *f) | |
503 | { | |
504 | struct bitfield_fetch_param *bprm; | |
505 | unsigned long bw, bo; | |
506 | char *tail; | |
507 | ||
508 | if (*bf != 'b') | |
509 | return 0; | |
510 | ||
511 | bprm = kzalloc(sizeof(*bprm), GFP_KERNEL); | |
512 | if (!bprm) | |
513 | return -ENOMEM; | |
514 | ||
515 | bprm->orig = *f; | |
516 | f->fn = t->fetch[FETCH_MTD_bitfield]; | |
517 | f->data = (void *)bprm; | |
518 | bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */ | |
519 | ||
520 | if (bw == 0 || *tail != '@') | |
521 | return -EINVAL; | |
522 | ||
523 | bf = tail + 1; | |
524 | bo = simple_strtoul(bf, &tail, 0); | |
525 | ||
526 | if (tail == bf || *tail != '/') | |
527 | return -EINVAL; | |
528 | ||
529 | bprm->hi_shift = BYTES_TO_BITS(t->size) - (bw + bo); | |
530 | bprm->low_shift = bprm->hi_shift + bo; | |
531 | ||
532 | return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0; | |
533 | } | |
534 | ||
535 | /* String length checking wrapper */ | |
536 | int traceprobe_parse_probe_arg(char *arg, ssize_t *size, | |
d9a16d3a SR |
537 | struct probe_arg *parg, bool is_return, bool is_kprobe, |
538 | const struct fetch_type *ftbl) | |
8ab83f56 SD |
539 | { |
540 | const char *t; | |
541 | int ret; | |
542 | ||
543 | if (strlen(arg) > MAX_ARGSTR_LEN) { | |
544 | pr_info("Argument is too long.: %s\n", arg); | |
545 | return -ENOSPC; | |
546 | } | |
547 | parg->comm = kstrdup(arg, GFP_KERNEL); | |
548 | if (!parg->comm) { | |
549 | pr_info("Failed to allocate memory for command '%s'.\n", arg); | |
550 | return -ENOMEM; | |
551 | } | |
552 | t = strchr(parg->comm, ':'); | |
553 | if (t) { | |
554 | arg[t - parg->comm] = '\0'; | |
555 | t++; | |
556 | } | |
35abb67d OS |
557 | /* |
558 | * The default type of $comm should be "string", and it can't be | |
559 | * dereferenced. | |
560 | */ | |
561 | if (!t && strcmp(arg, "$comm") == 0) | |
562 | t = "string"; | |
34fee3a1 | 563 | parg->type = find_fetch_type(t, ftbl); |
8ab83f56 SD |
564 | if (!parg->type) { |
565 | pr_info("Unsupported type: %s\n", t); | |
566 | return -EINVAL; | |
567 | } | |
568 | parg->offset = *size; | |
569 | *size += parg->type->size; | |
d9a16d3a SR |
570 | ret = parse_probe_arg(arg, parg->type, &parg->fetch, is_return, |
571 | is_kprobe, ftbl); | |
8ab83f56 SD |
572 | |
573 | if (ret >= 0 && t != NULL) | |
574 | ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch); | |
575 | ||
576 | if (ret >= 0) { | |
577 | parg->fetch_size.fn = get_fetch_size_function(parg->type, | |
34fee3a1 NK |
578 | parg->fetch.fn, |
579 | ftbl); | |
8ab83f56 SD |
580 | parg->fetch_size.data = parg->fetch.data; |
581 | } | |
582 | ||
583 | return ret; | |
584 | } | |
585 | ||
586 | /* Return 1 if name is reserved or already used by another argument */ | |
587 | int traceprobe_conflict_field_name(const char *name, | |
588 | struct probe_arg *args, int narg) | |
589 | { | |
590 | int i; | |
591 | ||
592 | for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++) | |
593 | if (strcmp(reserved_field_names[i], name) == 0) | |
594 | return 1; | |
595 | ||
596 | for (i = 0; i < narg; i++) | |
597 | if (strcmp(args[i].name, name) == 0) | |
598 | return 1; | |
599 | ||
600 | return 0; | |
601 | } | |
602 | ||
603 | void traceprobe_update_arg(struct probe_arg *arg) | |
604 | { | |
605 | if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn)) | |
606 | update_bitfield_fetch_param(arg->fetch.data); | |
607 | else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn)) | |
608 | update_deref_fetch_param(arg->fetch.data); | |
609 | else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn)) | |
610 | update_symbol_cache(arg->fetch.data); | |
611 | } | |
612 | ||
613 | void traceprobe_free_probe_arg(struct probe_arg *arg) | |
614 | { | |
615 | if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn)) | |
616 | free_bitfield_fetch_param(arg->fetch.data); | |
617 | else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn)) | |
618 | free_deref_fetch_param(arg->fetch.data); | |
619 | else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn)) | |
620 | free_symbol_cache(arg->fetch.data); | |
621 | ||
622 | kfree(arg->name); | |
623 | kfree(arg->comm); | |
624 | } | |
625 | ||
626 | int traceprobe_command(const char *buf, int (*createfn)(int, char **)) | |
627 | { | |
628 | char **argv; | |
629 | int argc, ret; | |
630 | ||
631 | argc = 0; | |
632 | ret = 0; | |
633 | argv = argv_split(GFP_KERNEL, buf, &argc); | |
634 | if (!argv) | |
635 | return -ENOMEM; | |
636 | ||
637 | if (argc) | |
638 | ret = createfn(argc, argv); | |
639 | ||
640 | argv_free(argv); | |
641 | ||
642 | return ret; | |
643 | } | |
644 | ||
645 | #define WRITE_BUFSIZE 4096 | |
646 | ||
647 | ssize_t traceprobe_probes_write(struct file *file, const char __user *buffer, | |
648 | size_t count, loff_t *ppos, | |
649 | int (*createfn)(int, char **)) | |
650 | { | |
1f9b3546 | 651 | char *kbuf, *buf, *tmp; |
8ab83f56 SD |
652 | int ret = 0; |
653 | size_t done = 0; | |
654 | size_t size; | |
655 | ||
656 | kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL); | |
657 | if (!kbuf) | |
658 | return -ENOMEM; | |
659 | ||
660 | while (done < count) { | |
661 | size = count - done; | |
662 | ||
663 | if (size >= WRITE_BUFSIZE) | |
664 | size = WRITE_BUFSIZE - 1; | |
665 | ||
666 | if (copy_from_user(kbuf, buffer + done, size)) { | |
667 | ret = -EFAULT; | |
668 | goto out; | |
669 | } | |
670 | kbuf[size] = '\0'; | |
1f9b3546 SRV |
671 | buf = kbuf; |
672 | do { | |
673 | tmp = strchr(buf, '\n'); | |
674 | if (tmp) { | |
675 | *tmp = '\0'; | |
676 | size = tmp - buf + 1; | |
677 | } else { | |
678 | size = strlen(buf); | |
679 | if (done + size < count) { | |
680 | if (buf != kbuf) | |
681 | break; | |
bef5da60 | 682 | /* This can accept WRITE_BUFSIZE - 2 ('\n' + '\0') */ |
1f9b3546 | 683 | pr_warn("Line length is too long: Should be less than %d\n", |
bef5da60 | 684 | WRITE_BUFSIZE - 2); |
1f9b3546 SRV |
685 | ret = -EINVAL; |
686 | goto out; | |
687 | } | |
688 | } | |
689 | done += size; | |
8ab83f56 | 690 | |
1f9b3546 SRV |
691 | /* Remove comments */ |
692 | tmp = strchr(buf, '#'); | |
8ab83f56 | 693 | |
1f9b3546 SRV |
694 | if (tmp) |
695 | *tmp = '\0'; | |
8ab83f56 | 696 | |
1f9b3546 SRV |
697 | ret = traceprobe_command(buf, createfn); |
698 | if (ret) | |
699 | goto out; | |
700 | buf += size; | |
701 | ||
702 | } while (done < count); | |
8ab83f56 SD |
703 | } |
704 | ret = done; | |
705 | ||
706 | out: | |
707 | kfree(kbuf); | |
708 | ||
709 | return ret; | |
710 | } | |
5bf652aa NK |
711 | |
712 | static int __set_print_fmt(struct trace_probe *tp, char *buf, int len, | |
713 | bool is_return) | |
714 | { | |
715 | int i; | |
716 | int pos = 0; | |
717 | ||
718 | const char *fmt, *arg; | |
719 | ||
720 | if (!is_return) { | |
721 | fmt = "(%lx)"; | |
722 | arg = "REC->" FIELD_STRING_IP; | |
723 | } else { | |
724 | fmt = "(%lx <- %lx)"; | |
725 | arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP; | |
726 | } | |
727 | ||
728 | /* When len=0, we just calculate the needed length */ | |
729 | #define LEN_OR_ZERO (len ? len - pos : 0) | |
730 | ||
731 | pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt); | |
732 | ||
733 | for (i = 0; i < tp->nr_args; i++) { | |
734 | pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%s", | |
735 | tp->args[i].name, tp->args[i].type->fmt); | |
736 | } | |
737 | ||
738 | pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg); | |
739 | ||
740 | for (i = 0; i < tp->nr_args; i++) { | |
741 | if (strcmp(tp->args[i].type->name, "string") == 0) | |
742 | pos += snprintf(buf + pos, LEN_OR_ZERO, | |
743 | ", __get_str(%s)", | |
744 | tp->args[i].name); | |
745 | else | |
746 | pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s", | |
747 | tp->args[i].name); | |
748 | } | |
749 | ||
750 | #undef LEN_OR_ZERO | |
751 | ||
752 | /* return the length of print_fmt */ | |
753 | return pos; | |
754 | } | |
755 | ||
756 | int set_print_fmt(struct trace_probe *tp, bool is_return) | |
757 | { | |
758 | int len; | |
759 | char *print_fmt; | |
760 | ||
761 | /* First: called with 0 length to calculate the needed length */ | |
762 | len = __set_print_fmt(tp, NULL, 0, is_return); | |
763 | print_fmt = kmalloc(len + 1, GFP_KERNEL); | |
764 | if (!print_fmt) | |
765 | return -ENOMEM; | |
766 | ||
767 | /* Second: actually write the @print_fmt */ | |
768 | __set_print_fmt(tp, print_fmt, len + 1, is_return); | |
769 | tp->call.print_fmt = print_fmt; | |
770 | ||
771 | return 0; | |
772 | } |