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Commit | Line | Data |
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413d37d1 | 1 | /* |
77b44d1b | 2 | * Kprobes-based tracing events |
413d37d1 MH |
3 | * |
4 | * Created by Masami Hiramatsu <mhiramat@redhat.com> | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program; if not, write to the Free Software | |
17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
18 | */ | |
19 | ||
20 | #include <linux/module.h> | |
21 | #include <linux/uaccess.h> | |
22 | #include <linux/kprobes.h> | |
23 | #include <linux/seq_file.h> | |
24 | #include <linux/slab.h> | |
25 | #include <linux/smp.h> | |
26 | #include <linux/debugfs.h> | |
27 | #include <linux/types.h> | |
28 | #include <linux/string.h> | |
29 | #include <linux/ctype.h> | |
30 | #include <linux/ptrace.h> | |
d7a4b414 | 31 | #include <linux/perf_event.h> |
93ccae7a | 32 | #include <linux/stringify.h> |
e09c8614 | 33 | #include <linux/limits.h> |
93ccae7a | 34 | #include <asm/bitsperlong.h> |
413d37d1 MH |
35 | |
36 | #include "trace.h" | |
37 | #include "trace_output.h" | |
38 | ||
a82378d8 | 39 | #define MAX_TRACE_ARGS 128 |
413d37d1 | 40 | #define MAX_ARGSTR_LEN 63 |
4263565d | 41 | #define MAX_EVENT_NAME_LEN 64 |
e09c8614 | 42 | #define MAX_STRING_SIZE PATH_MAX |
f52487e9 | 43 | #define KPROBE_EVENT_SYSTEM "kprobes" |
413d37d1 | 44 | |
a703d946 | 45 | /* Reserved field names */ |
e93f4d85 | 46 | #define FIELD_STRING_IP "__probe_ip" |
e93f4d85 MH |
47 | #define FIELD_STRING_RETIP "__probe_ret_ip" |
48 | #define FIELD_STRING_FUNC "__probe_func" | |
a703d946 MH |
49 | |
50 | const char *reserved_field_names[] = { | |
51 | "common_type", | |
52 | "common_flags", | |
53 | "common_preempt_count", | |
54 | "common_pid", | |
55 | "common_tgid", | |
56 | "common_lock_depth", | |
57 | FIELD_STRING_IP, | |
a703d946 MH |
58 | FIELD_STRING_RETIP, |
59 | FIELD_STRING_FUNC, | |
60 | }; | |
61 | ||
93ccae7a | 62 | /* Printing function type */ |
e09c8614 MH |
63 | typedef int (*print_type_func_t)(struct trace_seq *, const char *, void *, |
64 | void *); | |
93ccae7a MH |
65 | #define PRINT_TYPE_FUNC_NAME(type) print_type_##type |
66 | #define PRINT_TYPE_FMT_NAME(type) print_type_format_##type | |
67 | ||
68 | /* Printing in basic type function template */ | |
69 | #define DEFINE_BASIC_PRINT_TYPE_FUNC(type, fmt, cast) \ | |
70 | static __kprobes int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, \ | |
e09c8614 MH |
71 | const char *name, \ |
72 | void *data, void *ent)\ | |
93ccae7a MH |
73 | { \ |
74 | return trace_seq_printf(s, " %s=" fmt, name, (cast)*(type *)data);\ | |
75 | } \ | |
76 | static const char PRINT_TYPE_FMT_NAME(type)[] = fmt; | |
77 | ||
78 | DEFINE_BASIC_PRINT_TYPE_FUNC(u8, "%x", unsigned int) | |
79 | DEFINE_BASIC_PRINT_TYPE_FUNC(u16, "%x", unsigned int) | |
80 | DEFINE_BASIC_PRINT_TYPE_FUNC(u32, "%lx", unsigned long) | |
81 | DEFINE_BASIC_PRINT_TYPE_FUNC(u64, "%llx", unsigned long long) | |
82 | DEFINE_BASIC_PRINT_TYPE_FUNC(s8, "%d", int) | |
83 | DEFINE_BASIC_PRINT_TYPE_FUNC(s16, "%d", int) | |
84 | DEFINE_BASIC_PRINT_TYPE_FUNC(s32, "%ld", long) | |
85 | DEFINE_BASIC_PRINT_TYPE_FUNC(s64, "%lld", long long) | |
86 | ||
e09c8614 MH |
87 | /* data_rloc: data relative location, compatible with u32 */ |
88 | #define make_data_rloc(len, roffs) \ | |
89 | (((u32)(len) << 16) | ((u32)(roffs) & 0xffff)) | |
90 | #define get_rloc_len(dl) ((u32)(dl) >> 16) | |
91 | #define get_rloc_offs(dl) ((u32)(dl) & 0xffff) | |
92 | ||
93 | static inline void *get_rloc_data(u32 *dl) | |
94 | { | |
95 | return (u8 *)dl + get_rloc_offs(*dl); | |
96 | } | |
97 | ||
98 | /* For data_loc conversion */ | |
99 | static inline void *get_loc_data(u32 *dl, void *ent) | |
100 | { | |
101 | return (u8 *)ent + get_rloc_offs(*dl); | |
102 | } | |
103 | ||
104 | /* | |
105 | * Convert data_rloc to data_loc: | |
106 | * data_rloc stores the offset from data_rloc itself, but data_loc | |
107 | * stores the offset from event entry. | |
108 | */ | |
109 | #define convert_rloc_to_loc(dl, offs) ((u32)(dl) + (offs)) | |
110 | ||
111 | /* For defining macros, define string/string_size types */ | |
112 | typedef u32 string; | |
113 | typedef u32 string_size; | |
114 | ||
115 | /* Print type function for string type */ | |
116 | static __kprobes int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, | |
117 | const char *name, | |
118 | void *data, void *ent) | |
119 | { | |
120 | int len = *(u32 *)data >> 16; | |
121 | ||
122 | if (!len) | |
123 | return trace_seq_printf(s, " %s=(fault)", name); | |
124 | else | |
125 | return trace_seq_printf(s, " %s=\"%s\"", name, | |
126 | (const char *)get_loc_data(data, ent)); | |
127 | } | |
128 | static const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\""; | |
129 | ||
93ccae7a MH |
130 | /* Data fetch function type */ |
131 | typedef void (*fetch_func_t)(struct pt_regs *, void *, void *); | |
132 | ||
133 | struct fetch_param { | |
134 | fetch_func_t fn; | |
413d37d1 MH |
135 | void *data; |
136 | }; | |
137 | ||
93ccae7a MH |
138 | static __kprobes void call_fetch(struct fetch_param *fprm, |
139 | struct pt_regs *regs, void *dest) | |
413d37d1 | 140 | { |
93ccae7a | 141 | return fprm->fn(regs, fprm->data, dest); |
413d37d1 MH |
142 | } |
143 | ||
e09c8614 | 144 | #define FETCH_FUNC_NAME(method, type) fetch_##method##_##type |
93ccae7a MH |
145 | /* |
146 | * Define macro for basic types - we don't need to define s* types, because | |
147 | * we have to care only about bitwidth at recording time. | |
148 | */ | |
e09c8614 MH |
149 | #define DEFINE_BASIC_FETCH_FUNCS(method) \ |
150 | DEFINE_FETCH_##method(u8) \ | |
151 | DEFINE_FETCH_##method(u16) \ | |
152 | DEFINE_FETCH_##method(u32) \ | |
153 | DEFINE_FETCH_##method(u64) | |
154 | ||
155 | #define CHECK_FETCH_FUNCS(method, fn) \ | |
156 | (((FETCH_FUNC_NAME(method, u8) == fn) || \ | |
157 | (FETCH_FUNC_NAME(method, u16) == fn) || \ | |
158 | (FETCH_FUNC_NAME(method, u32) == fn) || \ | |
159 | (FETCH_FUNC_NAME(method, u64) == fn) || \ | |
160 | (FETCH_FUNC_NAME(method, string) == fn) || \ | |
161 | (FETCH_FUNC_NAME(method, string_size) == fn)) \ | |
162 | && (fn != NULL)) | |
93ccae7a MH |
163 | |
164 | /* Data fetch function templates */ | |
165 | #define DEFINE_FETCH_reg(type) \ | |
166 | static __kprobes void FETCH_FUNC_NAME(reg, type)(struct pt_regs *regs, \ | |
e09c8614 | 167 | void *offset, void *dest) \ |
93ccae7a MH |
168 | { \ |
169 | *(type *)dest = (type)regs_get_register(regs, \ | |
170 | (unsigned int)((unsigned long)offset)); \ | |
413d37d1 | 171 | } |
93ccae7a | 172 | DEFINE_BASIC_FETCH_FUNCS(reg) |
e09c8614 MH |
173 | /* No string on the register */ |
174 | #define fetch_reg_string NULL | |
175 | #define fetch_reg_string_size NULL | |
93ccae7a MH |
176 | |
177 | #define DEFINE_FETCH_stack(type) \ | |
178 | static __kprobes void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,\ | |
179 | void *offset, void *dest) \ | |
180 | { \ | |
181 | *(type *)dest = (type)regs_get_kernel_stack_nth(regs, \ | |
182 | (unsigned int)((unsigned long)offset)); \ | |
413d37d1 | 183 | } |
93ccae7a | 184 | DEFINE_BASIC_FETCH_FUNCS(stack) |
e09c8614 MH |
185 | /* No string on the stack entry */ |
186 | #define fetch_stack_string NULL | |
187 | #define fetch_stack_string_size NULL | |
413d37d1 | 188 | |
93ccae7a MH |
189 | #define DEFINE_FETCH_retval(type) \ |
190 | static __kprobes void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs,\ | |
191 | void *dummy, void *dest) \ | |
192 | { \ | |
193 | *(type *)dest = (type)regs_return_value(regs); \ | |
413d37d1 | 194 | } |
93ccae7a | 195 | DEFINE_BASIC_FETCH_FUNCS(retval) |
e09c8614 MH |
196 | /* No string on the retval */ |
197 | #define fetch_retval_string NULL | |
198 | #define fetch_retval_string_size NULL | |
93ccae7a MH |
199 | |
200 | #define DEFINE_FETCH_memory(type) \ | |
201 | static __kprobes void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs,\ | |
202 | void *addr, void *dest) \ | |
203 | { \ | |
204 | type retval; \ | |
205 | if (probe_kernel_address(addr, retval)) \ | |
206 | *(type *)dest = 0; \ | |
207 | else \ | |
208 | *(type *)dest = retval; \ | |
413d37d1 | 209 | } |
93ccae7a | 210 | DEFINE_BASIC_FETCH_FUNCS(memory) |
e09c8614 MH |
211 | /* |
212 | * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max | |
213 | * length and relative data location. | |
214 | */ | |
215 | static __kprobes void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs, | |
216 | void *addr, void *dest) | |
217 | { | |
218 | long ret; | |
219 | int maxlen = get_rloc_len(*(u32 *)dest); | |
220 | u8 *dst = get_rloc_data(dest); | |
221 | u8 *src = addr; | |
222 | mm_segment_t old_fs = get_fs(); | |
223 | if (!maxlen) | |
224 | return; | |
225 | /* | |
226 | * Try to get string again, since the string can be changed while | |
227 | * probing. | |
228 | */ | |
229 | set_fs(KERNEL_DS); | |
230 | pagefault_disable(); | |
231 | do | |
232 | ret = __copy_from_user_inatomic(dst++, src++, 1); | |
233 | while (dst[-1] && ret == 0 && src - (u8 *)addr < maxlen); | |
234 | dst[-1] = '\0'; | |
235 | pagefault_enable(); | |
236 | set_fs(old_fs); | |
237 | ||
238 | if (ret < 0) { /* Failed to fetch string */ | |
239 | ((u8 *)get_rloc_data(dest))[0] = '\0'; | |
240 | *(u32 *)dest = make_data_rloc(0, get_rloc_offs(*(u32 *)dest)); | |
241 | } else | |
242 | *(u32 *)dest = make_data_rloc(src - (u8 *)addr, | |
243 | get_rloc_offs(*(u32 *)dest)); | |
244 | } | |
245 | /* Return the length of string -- including null terminal byte */ | |
246 | static __kprobes void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs, | |
247 | void *addr, void *dest) | |
248 | { | |
249 | int ret, len = 0; | |
250 | u8 c; | |
251 | mm_segment_t old_fs = get_fs(); | |
252 | ||
253 | set_fs(KERNEL_DS); | |
254 | pagefault_disable(); | |
255 | do { | |
256 | ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1); | |
257 | len++; | |
258 | } while (c && ret == 0 && len < MAX_STRING_SIZE); | |
259 | pagefault_enable(); | |
260 | set_fs(old_fs); | |
261 | ||
262 | if (ret < 0) /* Failed to check the length */ | |
263 | *(u32 *)dest = 0; | |
264 | else | |
265 | *(u32 *)dest = len; | |
266 | } | |
413d37d1 MH |
267 | |
268 | /* Memory fetching by symbol */ | |
269 | struct symbol_cache { | |
270 | char *symbol; | |
271 | long offset; | |
272 | unsigned long addr; | |
273 | }; | |
274 | ||
275 | static unsigned long update_symbol_cache(struct symbol_cache *sc) | |
276 | { | |
277 | sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol); | |
278 | if (sc->addr) | |
279 | sc->addr += sc->offset; | |
280 | return sc->addr; | |
281 | } | |
282 | ||
283 | static void free_symbol_cache(struct symbol_cache *sc) | |
284 | { | |
285 | kfree(sc->symbol); | |
286 | kfree(sc); | |
287 | } | |
288 | ||
289 | static struct symbol_cache *alloc_symbol_cache(const char *sym, long offset) | |
290 | { | |
291 | struct symbol_cache *sc; | |
292 | ||
293 | if (!sym || strlen(sym) == 0) | |
294 | return NULL; | |
295 | sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL); | |
296 | if (!sc) | |
297 | return NULL; | |
298 | ||
299 | sc->symbol = kstrdup(sym, GFP_KERNEL); | |
300 | if (!sc->symbol) { | |
301 | kfree(sc); | |
302 | return NULL; | |
303 | } | |
304 | sc->offset = offset; | |
305 | ||
306 | update_symbol_cache(sc); | |
307 | return sc; | |
308 | } | |
309 | ||
93ccae7a MH |
310 | #define DEFINE_FETCH_symbol(type) \ |
311 | static __kprobes void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs,\ | |
312 | void *data, void *dest) \ | |
313 | { \ | |
314 | struct symbol_cache *sc = data; \ | |
315 | if (sc->addr) \ | |
316 | fetch_memory_##type(regs, (void *)sc->addr, dest); \ | |
317 | else \ | |
318 | *(type *)dest = 0; \ | |
413d37d1 | 319 | } |
93ccae7a | 320 | DEFINE_BASIC_FETCH_FUNCS(symbol) |
e09c8614 MH |
321 | DEFINE_FETCH_symbol(string) |
322 | DEFINE_FETCH_symbol(string_size) | |
413d37d1 | 323 | |
93ccae7a MH |
324 | /* Dereference memory access function */ |
325 | struct deref_fetch_param { | |
326 | struct fetch_param orig; | |
413d37d1 MH |
327 | long offset; |
328 | }; | |
329 | ||
93ccae7a MH |
330 | #define DEFINE_FETCH_deref(type) \ |
331 | static __kprobes void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs,\ | |
332 | void *data, void *dest) \ | |
333 | { \ | |
334 | struct deref_fetch_param *dprm = data; \ | |
335 | unsigned long addr; \ | |
336 | call_fetch(&dprm->orig, regs, &addr); \ | |
337 | if (addr) { \ | |
338 | addr += dprm->offset; \ | |
339 | fetch_memory_##type(regs, (void *)addr, dest); \ | |
340 | } else \ | |
341 | *(type *)dest = 0; \ | |
413d37d1 | 342 | } |
93ccae7a | 343 | DEFINE_BASIC_FETCH_FUNCS(deref) |
e09c8614 MH |
344 | DEFINE_FETCH_deref(string) |
345 | DEFINE_FETCH_deref(string_size) | |
413d37d1 | 346 | |
93ccae7a | 347 | static __kprobes void free_deref_fetch_param(struct deref_fetch_param *data) |
413d37d1 | 348 | { |
e09c8614 | 349 | if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) |
93ccae7a | 350 | free_deref_fetch_param(data->orig.data); |
e09c8614 | 351 | else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) |
413d37d1 MH |
352 | free_symbol_cache(data->orig.data); |
353 | kfree(data); | |
354 | } | |
355 | ||
93ccae7a MH |
356 | /* Default (unsigned long) fetch type */ |
357 | #define __DEFAULT_FETCH_TYPE(t) u##t | |
358 | #define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t) | |
359 | #define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG) | |
360 | #define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE) | |
361 | ||
e09c8614 MH |
362 | /* Fetch types */ |
363 | enum { | |
364 | FETCH_MTD_reg = 0, | |
365 | FETCH_MTD_stack, | |
366 | FETCH_MTD_retval, | |
367 | FETCH_MTD_memory, | |
368 | FETCH_MTD_symbol, | |
369 | FETCH_MTD_deref, | |
370 | FETCH_MTD_END, | |
371 | }; | |
372 | ||
373 | #define ASSIGN_FETCH_FUNC(method, type) \ | |
374 | [FETCH_MTD_##method] = FETCH_FUNC_NAME(method, type) | |
375 | ||
376 | #define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \ | |
377 | {.name = _name, \ | |
378 | .size = _size, \ | |
379 | .is_signed = sign, \ | |
380 | .print = PRINT_TYPE_FUNC_NAME(ptype), \ | |
381 | .fmt = PRINT_TYPE_FMT_NAME(ptype), \ | |
382 | .fmttype = _fmttype, \ | |
383 | .fetch = { \ | |
384 | ASSIGN_FETCH_FUNC(reg, ftype), \ | |
385 | ASSIGN_FETCH_FUNC(stack, ftype), \ | |
386 | ASSIGN_FETCH_FUNC(retval, ftype), \ | |
387 | ASSIGN_FETCH_FUNC(memory, ftype), \ | |
388 | ASSIGN_FETCH_FUNC(symbol, ftype), \ | |
389 | ASSIGN_FETCH_FUNC(deref, ftype), \ | |
390 | } \ | |
93ccae7a MH |
391 | } |
392 | ||
e09c8614 MH |
393 | #define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \ |
394 | __ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #ptype) | |
395 | ||
396 | #define FETCH_TYPE_STRING 0 | |
397 | #define FETCH_TYPE_STRSIZE 1 | |
398 | ||
93ccae7a MH |
399 | /* Fetch type information table */ |
400 | static const struct fetch_type { | |
401 | const char *name; /* Name of type */ | |
402 | size_t size; /* Byte size of type */ | |
403 | int is_signed; /* Signed flag */ | |
404 | print_type_func_t print; /* Print functions */ | |
405 | const char *fmt; /* Fromat string */ | |
e09c8614 | 406 | const char *fmttype; /* Name in format file */ |
93ccae7a | 407 | /* Fetch functions */ |
e09c8614 | 408 | fetch_func_t fetch[FETCH_MTD_END]; |
93ccae7a | 409 | } fetch_type_table[] = { |
e09c8614 MH |
410 | /* Special types */ |
411 | [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string, | |
412 | sizeof(u32), 1, "__data_loc char[]"), | |
413 | [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32, | |
414 | string_size, sizeof(u32), 0, "u32"), | |
415 | /* Basic types */ | |
93ccae7a MH |
416 | ASSIGN_FETCH_TYPE(u8, u8, 0), |
417 | ASSIGN_FETCH_TYPE(u16, u16, 0), | |
418 | ASSIGN_FETCH_TYPE(u32, u32, 0), | |
419 | ASSIGN_FETCH_TYPE(u64, u64, 0), | |
420 | ASSIGN_FETCH_TYPE(s8, u8, 1), | |
421 | ASSIGN_FETCH_TYPE(s16, u16, 1), | |
422 | ASSIGN_FETCH_TYPE(s32, u32, 1), | |
423 | ASSIGN_FETCH_TYPE(s64, u64, 1), | |
424 | }; | |
425 | ||
426 | static const struct fetch_type *find_fetch_type(const char *type) | |
427 | { | |
428 | int i; | |
429 | ||
430 | if (!type) | |
431 | type = DEFAULT_FETCH_TYPE_STR; | |
432 | ||
433 | for (i = 0; i < ARRAY_SIZE(fetch_type_table); i++) | |
434 | if (strcmp(type, fetch_type_table[i].name) == 0) | |
435 | return &fetch_type_table[i]; | |
436 | return NULL; | |
437 | } | |
438 | ||
439 | /* Special function : only accept unsigned long */ | |
440 | static __kprobes void fetch_stack_address(struct pt_regs *regs, | |
441 | void *dummy, void *dest) | |
442 | { | |
443 | *(unsigned long *)dest = kernel_stack_pointer(regs); | |
444 | } | |
445 | ||
e09c8614 MH |
446 | static fetch_func_t get_fetch_size_function(const struct fetch_type *type, |
447 | fetch_func_t orig_fn) | |
448 | { | |
449 | int i; | |
450 | ||
451 | if (type != &fetch_type_table[FETCH_TYPE_STRING]) | |
452 | return NULL; /* Only string type needs size function */ | |
453 | for (i = 0; i < FETCH_MTD_END; i++) | |
454 | if (type->fetch[i] == orig_fn) | |
455 | return fetch_type_table[FETCH_TYPE_STRSIZE].fetch[i]; | |
456 | ||
457 | WARN_ON(1); /* This should not happen */ | |
458 | return NULL; | |
459 | } | |
460 | ||
413d37d1 | 461 | /** |
77b44d1b | 462 | * Kprobe event core functions |
413d37d1 MH |
463 | */ |
464 | ||
eca0d916 | 465 | struct probe_arg { |
93ccae7a | 466 | struct fetch_param fetch; |
e09c8614 | 467 | struct fetch_param fetch_size; |
93ccae7a MH |
468 | unsigned int offset; /* Offset from argument entry */ |
469 | const char *name; /* Name of this argument */ | |
470 | const char *comm; /* Command of this argument */ | |
471 | const struct fetch_type *type; /* Type of this argument */ | |
eca0d916 MH |
472 | }; |
473 | ||
50d78056 MH |
474 | /* Flags for trace_probe */ |
475 | #define TP_FLAG_TRACE 1 | |
476 | #define TP_FLAG_PROFILE 2 | |
477 | ||
413d37d1 MH |
478 | struct trace_probe { |
479 | struct list_head list; | |
4a846b44 | 480 | struct kretprobe rp; /* Use rp.kp for kprobe use */ |
cd7e7bd5 | 481 | unsigned long nhit; |
50d78056 | 482 | unsigned int flags; /* For TP_FLAG_* */ |
413d37d1 | 483 | const char *symbol; /* symbol name */ |
2239291a | 484 | struct ftrace_event_class class; |
413d37d1 | 485 | struct ftrace_event_call call; |
93ccae7a | 486 | ssize_t size; /* trace entry size */ |
a82378d8 | 487 | unsigned int nr_args; |
eca0d916 | 488 | struct probe_arg args[]; |
413d37d1 MH |
489 | }; |
490 | ||
a82378d8 MH |
491 | #define SIZEOF_TRACE_PROBE(n) \ |
492 | (offsetof(struct trace_probe, args) + \ | |
eca0d916 | 493 | (sizeof(struct probe_arg) * (n))) |
a82378d8 | 494 | |
93ccae7a | 495 | |
413d37d1 MH |
496 | static __kprobes int probe_is_return(struct trace_probe *tp) |
497 | { | |
4a846b44 | 498 | return tp->rp.handler != NULL; |
413d37d1 MH |
499 | } |
500 | ||
501 | static __kprobes const char *probe_symbol(struct trace_probe *tp) | |
502 | { | |
503 | return tp->symbol ? tp->symbol : "unknown"; | |
504 | } | |
505 | ||
413d37d1 MH |
506 | static int register_probe_event(struct trace_probe *tp); |
507 | static void unregister_probe_event(struct trace_probe *tp); | |
508 | ||
509 | static DEFINE_MUTEX(probe_lock); | |
510 | static LIST_HEAD(probe_list); | |
511 | ||
50d78056 MH |
512 | static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs); |
513 | static int kretprobe_dispatcher(struct kretprobe_instance *ri, | |
514 | struct pt_regs *regs); | |
515 | ||
da34634f MH |
516 | /* Check the name is good for event/group/fields */ |
517 | static int is_good_name(const char *name) | |
6f3cf440 MH |
518 | { |
519 | if (!isalpha(*name) && *name != '_') | |
520 | return 0; | |
521 | while (*++name != '\0') { | |
522 | if (!isalpha(*name) && !isdigit(*name) && *name != '_') | |
523 | return 0; | |
524 | } | |
525 | return 1; | |
526 | } | |
527 | ||
4a846b44 MH |
528 | /* |
529 | * Allocate new trace_probe and initialize it (including kprobes). | |
530 | */ | |
f52487e9 MH |
531 | static struct trace_probe *alloc_trace_probe(const char *group, |
532 | const char *event, | |
4a846b44 MH |
533 | void *addr, |
534 | const char *symbol, | |
535 | unsigned long offs, | |
536 | int nargs, int is_return) | |
413d37d1 MH |
537 | { |
538 | struct trace_probe *tp; | |
6f3cf440 | 539 | int ret = -ENOMEM; |
413d37d1 | 540 | |
a82378d8 | 541 | tp = kzalloc(SIZEOF_TRACE_PROBE(nargs), GFP_KERNEL); |
413d37d1 | 542 | if (!tp) |
6f3cf440 | 543 | return ERR_PTR(ret); |
413d37d1 MH |
544 | |
545 | if (symbol) { | |
546 | tp->symbol = kstrdup(symbol, GFP_KERNEL); | |
547 | if (!tp->symbol) | |
548 | goto error; | |
4a846b44 MH |
549 | tp->rp.kp.symbol_name = tp->symbol; |
550 | tp->rp.kp.offset = offs; | |
551 | } else | |
552 | tp->rp.kp.addr = addr; | |
553 | ||
554 | if (is_return) | |
50d78056 | 555 | tp->rp.handler = kretprobe_dispatcher; |
4a846b44 | 556 | else |
50d78056 | 557 | tp->rp.kp.pre_handler = kprobe_dispatcher; |
4a846b44 | 558 | |
da34634f | 559 | if (!event || !is_good_name(event)) { |
6f3cf440 | 560 | ret = -EINVAL; |
4263565d | 561 | goto error; |
6f3cf440 MH |
562 | } |
563 | ||
2239291a | 564 | tp->call.class = &tp->class; |
4263565d MH |
565 | tp->call.name = kstrdup(event, GFP_KERNEL); |
566 | if (!tp->call.name) | |
567 | goto error; | |
413d37d1 | 568 | |
da34634f | 569 | if (!group || !is_good_name(group)) { |
6f3cf440 | 570 | ret = -EINVAL; |
f52487e9 | 571 | goto error; |
6f3cf440 MH |
572 | } |
573 | ||
2239291a SR |
574 | tp->class.system = kstrdup(group, GFP_KERNEL); |
575 | if (!tp->class.system) | |
f52487e9 MH |
576 | goto error; |
577 | ||
413d37d1 MH |
578 | INIT_LIST_HEAD(&tp->list); |
579 | return tp; | |
580 | error: | |
f52487e9 | 581 | kfree(tp->call.name); |
413d37d1 MH |
582 | kfree(tp->symbol); |
583 | kfree(tp); | |
6f3cf440 | 584 | return ERR_PTR(ret); |
413d37d1 MH |
585 | } |
586 | ||
eca0d916 MH |
587 | static void free_probe_arg(struct probe_arg *arg) |
588 | { | |
e09c8614 | 589 | if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn)) |
93ccae7a | 590 | free_deref_fetch_param(arg->fetch.data); |
e09c8614 | 591 | else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn)) |
eca0d916 | 592 | free_symbol_cache(arg->fetch.data); |
eca0d916 | 593 | kfree(arg->name); |
93ccae7a | 594 | kfree(arg->comm); |
eca0d916 MH |
595 | } |
596 | ||
413d37d1 MH |
597 | static void free_trace_probe(struct trace_probe *tp) |
598 | { | |
599 | int i; | |
600 | ||
601 | for (i = 0; i < tp->nr_args; i++) | |
eca0d916 | 602 | free_probe_arg(&tp->args[i]); |
413d37d1 | 603 | |
8f082018 | 604 | kfree(tp->call.class->system); |
413d37d1 MH |
605 | kfree(tp->call.name); |
606 | kfree(tp->symbol); | |
607 | kfree(tp); | |
608 | } | |
609 | ||
dd004c47 MH |
610 | static struct trace_probe *find_probe_event(const char *event, |
611 | const char *group) | |
413d37d1 MH |
612 | { |
613 | struct trace_probe *tp; | |
614 | ||
615 | list_for_each_entry(tp, &probe_list, list) | |
dd004c47 | 616 | if (strcmp(tp->call.name, event) == 0 && |
8f082018 | 617 | strcmp(tp->call.class->system, group) == 0) |
413d37d1 MH |
618 | return tp; |
619 | return NULL; | |
620 | } | |
621 | ||
2d5e067e MH |
622 | /* Unregister a trace_probe and probe_event: call with locking probe_lock */ |
623 | static void unregister_trace_probe(struct trace_probe *tp) | |
413d37d1 MH |
624 | { |
625 | if (probe_is_return(tp)) | |
626 | unregister_kretprobe(&tp->rp); | |
627 | else | |
4a846b44 | 628 | unregister_kprobe(&tp->rp.kp); |
413d37d1 | 629 | list_del(&tp->list); |
2d5e067e | 630 | unregister_probe_event(tp); |
413d37d1 MH |
631 | } |
632 | ||
633 | /* Register a trace_probe and probe_event */ | |
634 | static int register_trace_probe(struct trace_probe *tp) | |
635 | { | |
636 | struct trace_probe *old_tp; | |
637 | int ret; | |
638 | ||
639 | mutex_lock(&probe_lock); | |
640 | ||
2d5e067e | 641 | /* register as an event */ |
8f082018 | 642 | old_tp = find_probe_event(tp->call.name, tp->call.class->system); |
2d5e067e MH |
643 | if (old_tp) { |
644 | /* delete old event */ | |
645 | unregister_trace_probe(old_tp); | |
646 | free_trace_probe(old_tp); | |
647 | } | |
648 | ret = register_probe_event(tp); | |
649 | if (ret) { | |
426d3107 | 650 | pr_warning("Failed to register probe event(%d)\n", ret); |
2d5e067e MH |
651 | goto end; |
652 | } | |
653 | ||
5a0d9050 | 654 | tp->rp.kp.flags |= KPROBE_FLAG_DISABLED; |
413d37d1 MH |
655 | if (probe_is_return(tp)) |
656 | ret = register_kretprobe(&tp->rp); | |
657 | else | |
4a846b44 | 658 | ret = register_kprobe(&tp->rp.kp); |
413d37d1 MH |
659 | |
660 | if (ret) { | |
661 | pr_warning("Could not insert probe(%d)\n", ret); | |
662 | if (ret == -EILSEQ) { | |
663 | pr_warning("Probing address(0x%p) is not an " | |
664 | "instruction boundary.\n", | |
4a846b44 | 665 | tp->rp.kp.addr); |
413d37d1 MH |
666 | ret = -EINVAL; |
667 | } | |
2d5e067e MH |
668 | unregister_probe_event(tp); |
669 | } else | |
670 | list_add_tail(&tp->list, &probe_list); | |
413d37d1 MH |
671 | end: |
672 | mutex_unlock(&probe_lock); | |
673 | return ret; | |
674 | } | |
675 | ||
676 | /* Split symbol and offset. */ | |
2fba0c88 | 677 | static int split_symbol_offset(char *symbol, unsigned long *offset) |
413d37d1 MH |
678 | { |
679 | char *tmp; | |
680 | int ret; | |
681 | ||
682 | if (!offset) | |
683 | return -EINVAL; | |
684 | ||
685 | tmp = strchr(symbol, '+'); | |
413d37d1 MH |
686 | if (tmp) { |
687 | /* skip sign because strict_strtol doesn't accept '+' */ | |
2fba0c88 | 688 | ret = strict_strtoul(tmp + 1, 0, offset); |
413d37d1 MH |
689 | if (ret) |
690 | return ret; | |
413d37d1 MH |
691 | *tmp = '\0'; |
692 | } else | |
693 | *offset = 0; | |
694 | return 0; | |
695 | } | |
696 | ||
697 | #define PARAM_MAX_ARGS 16 | |
698 | #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long)) | |
699 | ||
93ccae7a MH |
700 | static int parse_probe_vars(char *arg, const struct fetch_type *t, |
701 | struct fetch_param *f, int is_return) | |
413d37d1 MH |
702 | { |
703 | int ret = 0; | |
704 | unsigned long param; | |
413d37d1 | 705 | |
2e06ff63 | 706 | if (strcmp(arg, "retval") == 0) { |
93ccae7a | 707 | if (is_return) |
e09c8614 | 708 | f->fn = t->fetch[FETCH_MTD_retval]; |
93ccae7a | 709 | else |
413d37d1 | 710 | ret = -EINVAL; |
2e06ff63 MH |
711 | } else if (strncmp(arg, "stack", 5) == 0) { |
712 | if (arg[5] == '\0') { | |
93ccae7a MH |
713 | if (strcmp(t->name, DEFAULT_FETCH_TYPE_STR) == 0) |
714 | f->fn = fetch_stack_address; | |
715 | else | |
716 | ret = -EINVAL; | |
2e06ff63 MH |
717 | } else if (isdigit(arg[5])) { |
718 | ret = strict_strtoul(arg + 5, 10, ¶m); | |
413d37d1 MH |
719 | if (ret || param > PARAM_MAX_STACK) |
720 | ret = -EINVAL; | |
721 | else { | |
e09c8614 | 722 | f->fn = t->fetch[FETCH_MTD_stack]; |
93ccae7a | 723 | f->data = (void *)param; |
413d37d1 | 724 | } |
2e06ff63 MH |
725 | } else |
726 | ret = -EINVAL; | |
2e06ff63 | 727 | } else |
405b2651 | 728 | ret = -EINVAL; |
405b2651 MH |
729 | return ret; |
730 | } | |
731 | ||
ba8665d7 | 732 | /* Recursive argument parser */ |
93ccae7a MH |
733 | static int __parse_probe_arg(char *arg, const struct fetch_type *t, |
734 | struct fetch_param *f, int is_return) | |
405b2651 MH |
735 | { |
736 | int ret = 0; | |
737 | unsigned long param; | |
738 | long offset; | |
739 | char *tmp; | |
740 | ||
741 | switch (arg[0]) { | |
742 | case '$': | |
93ccae7a | 743 | ret = parse_probe_vars(arg + 1, t, f, is_return); |
405b2651 MH |
744 | break; |
745 | case '%': /* named register */ | |
746 | ret = regs_query_register_offset(arg + 1); | |
747 | if (ret >= 0) { | |
e09c8614 | 748 | f->fn = t->fetch[FETCH_MTD_reg]; |
93ccae7a | 749 | f->data = (void *)(unsigned long)ret; |
405b2651 MH |
750 | ret = 0; |
751 | } | |
752 | break; | |
413d37d1 MH |
753 | case '@': /* memory or symbol */ |
754 | if (isdigit(arg[1])) { | |
755 | ret = strict_strtoul(arg + 1, 0, ¶m); | |
756 | if (ret) | |
757 | break; | |
e09c8614 | 758 | f->fn = t->fetch[FETCH_MTD_memory]; |
93ccae7a | 759 | f->data = (void *)param; |
413d37d1 MH |
760 | } else { |
761 | ret = split_symbol_offset(arg + 1, &offset); | |
762 | if (ret) | |
763 | break; | |
93ccae7a MH |
764 | f->data = alloc_symbol_cache(arg + 1, offset); |
765 | if (f->data) | |
e09c8614 | 766 | f->fn = t->fetch[FETCH_MTD_symbol]; |
413d37d1 MH |
767 | } |
768 | break; | |
93ccae7a | 769 | case '+': /* deref memory */ |
413d37d1 MH |
770 | case '-': |
771 | tmp = strchr(arg, '('); | |
93ccae7a | 772 | if (!tmp) |
413d37d1 | 773 | break; |
413d37d1 MH |
774 | *tmp = '\0'; |
775 | ret = strict_strtol(arg + 1, 0, &offset); | |
776 | if (ret) | |
777 | break; | |
778 | if (arg[0] == '-') | |
779 | offset = -offset; | |
780 | arg = tmp + 1; | |
781 | tmp = strrchr(arg, ')'); | |
782 | if (tmp) { | |
93ccae7a MH |
783 | struct deref_fetch_param *dprm; |
784 | const struct fetch_type *t2 = find_fetch_type(NULL); | |
413d37d1 | 785 | *tmp = '\0'; |
93ccae7a MH |
786 | dprm = kzalloc(sizeof(struct deref_fetch_param), |
787 | GFP_KERNEL); | |
788 | if (!dprm) | |
413d37d1 | 789 | return -ENOMEM; |
93ccae7a MH |
790 | dprm->offset = offset; |
791 | ret = __parse_probe_arg(arg, t2, &dprm->orig, | |
792 | is_return); | |
413d37d1 | 793 | if (ret) |
93ccae7a | 794 | kfree(dprm); |
413d37d1 | 795 | else { |
e09c8614 | 796 | f->fn = t->fetch[FETCH_MTD_deref]; |
93ccae7a | 797 | f->data = (void *)dprm; |
413d37d1 | 798 | } |
93ccae7a | 799 | } |
413d37d1 | 800 | break; |
413d37d1 | 801 | } |
e09c8614 MH |
802 | if (!ret && !f->fn) { /* Parsed, but do not find fetch method */ |
803 | pr_info("%s type has no corresponding fetch method.\n", | |
804 | t->name); | |
93ccae7a | 805 | ret = -EINVAL; |
e09c8614 | 806 | } |
413d37d1 MH |
807 | return ret; |
808 | } | |
809 | ||
ba8665d7 | 810 | /* String length checking wrapper */ |
93ccae7a MH |
811 | static int parse_probe_arg(char *arg, struct trace_probe *tp, |
812 | struct probe_arg *parg, int is_return) | |
ba8665d7 | 813 | { |
93ccae7a | 814 | const char *t; |
e09c8614 | 815 | int ret; |
93ccae7a | 816 | |
ba8665d7 MH |
817 | if (strlen(arg) > MAX_ARGSTR_LEN) { |
818 | pr_info("Argument is too long.: %s\n", arg); | |
819 | return -ENOSPC; | |
820 | } | |
93ccae7a MH |
821 | parg->comm = kstrdup(arg, GFP_KERNEL); |
822 | if (!parg->comm) { | |
823 | pr_info("Failed to allocate memory for command '%s'.\n", arg); | |
824 | return -ENOMEM; | |
825 | } | |
826 | t = strchr(parg->comm, ':'); | |
827 | if (t) { | |
828 | arg[t - parg->comm] = '\0'; | |
829 | t++; | |
830 | } | |
831 | parg->type = find_fetch_type(t); | |
832 | if (!parg->type) { | |
833 | pr_info("Unsupported type: %s\n", t); | |
834 | return -EINVAL; | |
835 | } | |
836 | parg->offset = tp->size; | |
837 | tp->size += parg->type->size; | |
e09c8614 MH |
838 | ret = __parse_probe_arg(arg, parg->type, &parg->fetch, is_return); |
839 | if (ret >= 0) { | |
840 | parg->fetch_size.fn = get_fetch_size_function(parg->type, | |
841 | parg->fetch.fn); | |
842 | parg->fetch_size.data = parg->fetch.data; | |
843 | } | |
844 | return ret; | |
ba8665d7 MH |
845 | } |
846 | ||
a703d946 MH |
847 | /* Return 1 if name is reserved or already used by another argument */ |
848 | static int conflict_field_name(const char *name, | |
849 | struct probe_arg *args, int narg) | |
850 | { | |
851 | int i; | |
852 | for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++) | |
853 | if (strcmp(reserved_field_names[i], name) == 0) | |
854 | return 1; | |
855 | for (i = 0; i < narg; i++) | |
856 | if (strcmp(args[i].name, name) == 0) | |
857 | return 1; | |
858 | return 0; | |
859 | } | |
860 | ||
413d37d1 MH |
861 | static int create_trace_probe(int argc, char **argv) |
862 | { | |
863 | /* | |
864 | * Argument syntax: | |
f52487e9 MH |
865 | * - Add kprobe: p[:[GRP/]EVENT] KSYM[+OFFS]|KADDR [FETCHARGS] |
866 | * - Add kretprobe: r[:[GRP/]EVENT] KSYM[+0] [FETCHARGS] | |
413d37d1 | 867 | * Fetch args: |
2e06ff63 MH |
868 | * $retval : fetch return value |
869 | * $stack : fetch stack address | |
870 | * $stackN : fetch Nth of stack (N:0-) | |
413d37d1 MH |
871 | * @ADDR : fetch memory at ADDR (ADDR should be in kernel) |
872 | * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol) | |
873 | * %REG : fetch register REG | |
93ccae7a | 874 | * Dereferencing memory fetch: |
413d37d1 | 875 | * +|-offs(ARG) : fetch memory at ARG +|- offs address. |
eca0d916 MH |
876 | * Alias name of args: |
877 | * NAME=FETCHARG : set NAME as alias of FETCHARG. | |
93ccae7a MH |
878 | * Type of args: |
879 | * FETCHARG:TYPE : use TYPE instead of unsigned long. | |
413d37d1 MH |
880 | */ |
881 | struct trace_probe *tp; | |
413d37d1 | 882 | int i, ret = 0; |
a7c312be | 883 | int is_return = 0, is_delete = 0; |
93ccae7a | 884 | char *symbol = NULL, *event = NULL, *group = NULL; |
da34634f | 885 | char *arg; |
2fba0c88 | 886 | unsigned long offset = 0; |
413d37d1 | 887 | void *addr = NULL; |
4a846b44 | 888 | char buf[MAX_EVENT_NAME_LEN]; |
413d37d1 | 889 | |
a7c312be | 890 | /* argc must be >= 1 */ |
413d37d1 MH |
891 | if (argv[0][0] == 'p') |
892 | is_return = 0; | |
893 | else if (argv[0][0] == 'r') | |
894 | is_return = 1; | |
a7c312be MH |
895 | else if (argv[0][0] == '-') |
896 | is_delete = 1; | |
e63cc239 | 897 | else { |
a7c312be MH |
898 | pr_info("Probe definition must be started with 'p', 'r' or" |
899 | " '-'.\n"); | |
413d37d1 | 900 | return -EINVAL; |
e63cc239 | 901 | } |
413d37d1 MH |
902 | |
903 | if (argv[0][1] == ':') { | |
904 | event = &argv[0][2]; | |
f52487e9 MH |
905 | if (strchr(event, '/')) { |
906 | group = event; | |
907 | event = strchr(group, '/') + 1; | |
908 | event[-1] = '\0'; | |
909 | if (strlen(group) == 0) { | |
a5efd925 | 910 | pr_info("Group name is not specified\n"); |
f52487e9 MH |
911 | return -EINVAL; |
912 | } | |
913 | } | |
413d37d1 | 914 | if (strlen(event) == 0) { |
a5efd925 | 915 | pr_info("Event name is not specified\n"); |
413d37d1 MH |
916 | return -EINVAL; |
917 | } | |
918 | } | |
a7c312be MH |
919 | if (!group) |
920 | group = KPROBE_EVENT_SYSTEM; | |
413d37d1 | 921 | |
a7c312be MH |
922 | if (is_delete) { |
923 | if (!event) { | |
924 | pr_info("Delete command needs an event name.\n"); | |
925 | return -EINVAL; | |
926 | } | |
9da79ab8 | 927 | mutex_lock(&probe_lock); |
a7c312be MH |
928 | tp = find_probe_event(event, group); |
929 | if (!tp) { | |
9da79ab8 | 930 | mutex_unlock(&probe_lock); |
a7c312be MH |
931 | pr_info("Event %s/%s doesn't exist.\n", group, event); |
932 | return -ENOENT; | |
933 | } | |
934 | /* delete an event */ | |
935 | unregister_trace_probe(tp); | |
936 | free_trace_probe(tp); | |
9da79ab8 | 937 | mutex_unlock(&probe_lock); |
a7c312be MH |
938 | return 0; |
939 | } | |
940 | ||
941 | if (argc < 2) { | |
942 | pr_info("Probe point is not specified.\n"); | |
943 | return -EINVAL; | |
944 | } | |
413d37d1 | 945 | if (isdigit(argv[1][0])) { |
e63cc239 MH |
946 | if (is_return) { |
947 | pr_info("Return probe point must be a symbol.\n"); | |
413d37d1 | 948 | return -EINVAL; |
e63cc239 | 949 | } |
413d37d1 | 950 | /* an address specified */ |
a9bb18f3 | 951 | ret = strict_strtoul(&argv[1][0], 0, (unsigned long *)&addr); |
e63cc239 MH |
952 | if (ret) { |
953 | pr_info("Failed to parse address.\n"); | |
413d37d1 | 954 | return ret; |
e63cc239 | 955 | } |
413d37d1 MH |
956 | } else { |
957 | /* a symbol specified */ | |
958 | symbol = argv[1]; | |
959 | /* TODO: support .init module functions */ | |
960 | ret = split_symbol_offset(symbol, &offset); | |
e63cc239 MH |
961 | if (ret) { |
962 | pr_info("Failed to parse symbol.\n"); | |
413d37d1 | 963 | return ret; |
e63cc239 MH |
964 | } |
965 | if (offset && is_return) { | |
966 | pr_info("Return probe must be used without offset.\n"); | |
413d37d1 | 967 | return -EINVAL; |
e63cc239 | 968 | } |
413d37d1 | 969 | } |
a82378d8 | 970 | argc -= 2; argv += 2; |
413d37d1 MH |
971 | |
972 | /* setup a probe */ | |
4263565d MH |
973 | if (!event) { |
974 | /* Make a new event name */ | |
4263565d | 975 | if (symbol) |
6f3cf440 | 976 | snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld", |
4263565d MH |
977 | is_return ? 'r' : 'p', symbol, offset); |
978 | else | |
6f3cf440 | 979 | snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p", |
4263565d | 980 | is_return ? 'r' : 'p', addr); |
4a846b44 MH |
981 | event = buf; |
982 | } | |
f52487e9 MH |
983 | tp = alloc_trace_probe(group, event, addr, symbol, offset, argc, |
984 | is_return); | |
e63cc239 MH |
985 | if (IS_ERR(tp)) { |
986 | pr_info("Failed to allocate trace_probe.(%d)\n", | |
987 | (int)PTR_ERR(tp)); | |
413d37d1 | 988 | return PTR_ERR(tp); |
e63cc239 | 989 | } |
413d37d1 | 990 | |
413d37d1 | 991 | /* parse arguments */ |
a82378d8 MH |
992 | ret = 0; |
993 | for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { | |
61a52736 MH |
994 | /* Increment count for freeing args in error case */ |
995 | tp->nr_args++; | |
996 | ||
eca0d916 MH |
997 | /* Parse argument name */ |
998 | arg = strchr(argv[i], '='); | |
aba91595 | 999 | if (arg) { |
eca0d916 | 1000 | *arg++ = '\0'; |
aba91595 MH |
1001 | tp->args[i].name = kstrdup(argv[i], GFP_KERNEL); |
1002 | } else { | |
eca0d916 | 1003 | arg = argv[i]; |
aba91595 MH |
1004 | /* If argument name is omitted, set "argN" */ |
1005 | snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1); | |
1006 | tp->args[i].name = kstrdup(buf, GFP_KERNEL); | |
1007 | } | |
a703d946 | 1008 | |
ba8665d7 | 1009 | if (!tp->args[i].name) { |
aba91595 | 1010 | pr_info("Failed to allocate argument[%d] name.\n", i); |
ba8665d7 | 1011 | ret = -ENOMEM; |
413d37d1 MH |
1012 | goto error; |
1013 | } | |
da34634f MH |
1014 | |
1015 | if (!is_good_name(tp->args[i].name)) { | |
1016 | pr_info("Invalid argument[%d] name: %s\n", | |
1017 | i, tp->args[i].name); | |
1018 | ret = -EINVAL; | |
1019 | goto error; | |
1020 | } | |
93ccae7a MH |
1021 | |
1022 | if (conflict_field_name(tp->args[i].name, tp->args, i)) { | |
aba91595 | 1023 | pr_info("Argument[%d] name '%s' conflicts with " |
93ccae7a MH |
1024 | "another field.\n", i, argv[i]); |
1025 | ret = -EINVAL; | |
1026 | goto error; | |
1027 | } | |
ba8665d7 MH |
1028 | |
1029 | /* Parse fetch argument */ | |
93ccae7a | 1030 | ret = parse_probe_arg(arg, tp, &tp->args[i], is_return); |
e63cc239 | 1031 | if (ret) { |
aba91595 | 1032 | pr_info("Parse error at argument[%d]. (%d)\n", i, ret); |
413d37d1 | 1033 | goto error; |
e63cc239 | 1034 | } |
413d37d1 | 1035 | } |
413d37d1 MH |
1036 | |
1037 | ret = register_trace_probe(tp); | |
1038 | if (ret) | |
1039 | goto error; | |
1040 | return 0; | |
1041 | ||
1042 | error: | |
1043 | free_trace_probe(tp); | |
1044 | return ret; | |
1045 | } | |
1046 | ||
1047 | static void cleanup_all_probes(void) | |
1048 | { | |
1049 | struct trace_probe *tp; | |
1050 | ||
1051 | mutex_lock(&probe_lock); | |
1052 | /* TODO: Use batch unregistration */ | |
1053 | while (!list_empty(&probe_list)) { | |
1054 | tp = list_entry(probe_list.next, struct trace_probe, list); | |
1055 | unregister_trace_probe(tp); | |
1056 | free_trace_probe(tp); | |
1057 | } | |
1058 | mutex_unlock(&probe_lock); | |
1059 | } | |
1060 | ||
1061 | ||
1062 | /* Probes listing interfaces */ | |
1063 | static void *probes_seq_start(struct seq_file *m, loff_t *pos) | |
1064 | { | |
1065 | mutex_lock(&probe_lock); | |
1066 | return seq_list_start(&probe_list, *pos); | |
1067 | } | |
1068 | ||
1069 | static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos) | |
1070 | { | |
1071 | return seq_list_next(v, &probe_list, pos); | |
1072 | } | |
1073 | ||
1074 | static void probes_seq_stop(struct seq_file *m, void *v) | |
1075 | { | |
1076 | mutex_unlock(&probe_lock); | |
1077 | } | |
1078 | ||
1079 | static int probes_seq_show(struct seq_file *m, void *v) | |
1080 | { | |
1081 | struct trace_probe *tp = v; | |
93ccae7a | 1082 | int i; |
413d37d1 MH |
1083 | |
1084 | seq_printf(m, "%c", probe_is_return(tp) ? 'r' : 'p'); | |
8f082018 | 1085 | seq_printf(m, ":%s/%s", tp->call.class->system, tp->call.name); |
413d37d1 | 1086 | |
52a11f35 LJ |
1087 | if (!tp->symbol) |
1088 | seq_printf(m, " 0x%p", tp->rp.kp.addr); | |
1089 | else if (tp->rp.kp.offset) | |
4a846b44 | 1090 | seq_printf(m, " %s+%u", probe_symbol(tp), tp->rp.kp.offset); |
413d37d1 | 1091 | else |
52a11f35 | 1092 | seq_printf(m, " %s", probe_symbol(tp)); |
413d37d1 | 1093 | |
93ccae7a MH |
1094 | for (i = 0; i < tp->nr_args; i++) |
1095 | seq_printf(m, " %s=%s", tp->args[i].name, tp->args[i].comm); | |
413d37d1 | 1096 | seq_printf(m, "\n"); |
93ccae7a | 1097 | |
413d37d1 MH |
1098 | return 0; |
1099 | } | |
1100 | ||
1101 | static const struct seq_operations probes_seq_op = { | |
1102 | .start = probes_seq_start, | |
1103 | .next = probes_seq_next, | |
1104 | .stop = probes_seq_stop, | |
1105 | .show = probes_seq_show | |
1106 | }; | |
1107 | ||
1108 | static int probes_open(struct inode *inode, struct file *file) | |
1109 | { | |
1110 | if ((file->f_mode & FMODE_WRITE) && | |
1111 | (file->f_flags & O_TRUNC)) | |
1112 | cleanup_all_probes(); | |
1113 | ||
1114 | return seq_open(file, &probes_seq_op); | |
1115 | } | |
1116 | ||
1117 | static int command_trace_probe(const char *buf) | |
1118 | { | |
1119 | char **argv; | |
1120 | int argc = 0, ret = 0; | |
1121 | ||
1122 | argv = argv_split(GFP_KERNEL, buf, &argc); | |
1123 | if (!argv) | |
1124 | return -ENOMEM; | |
1125 | ||
1126 | if (argc) | |
1127 | ret = create_trace_probe(argc, argv); | |
1128 | ||
1129 | argv_free(argv); | |
1130 | return ret; | |
1131 | } | |
1132 | ||
1133 | #define WRITE_BUFSIZE 128 | |
1134 | ||
1135 | static ssize_t probes_write(struct file *file, const char __user *buffer, | |
1136 | size_t count, loff_t *ppos) | |
1137 | { | |
1138 | char *kbuf, *tmp; | |
1139 | int ret; | |
1140 | size_t done; | |
1141 | size_t size; | |
1142 | ||
1143 | kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL); | |
1144 | if (!kbuf) | |
1145 | return -ENOMEM; | |
1146 | ||
1147 | ret = done = 0; | |
1148 | while (done < count) { | |
1149 | size = count - done; | |
1150 | if (size >= WRITE_BUFSIZE) | |
1151 | size = WRITE_BUFSIZE - 1; | |
1152 | if (copy_from_user(kbuf, buffer + done, size)) { | |
1153 | ret = -EFAULT; | |
1154 | goto out; | |
1155 | } | |
1156 | kbuf[size] = '\0'; | |
1157 | tmp = strchr(kbuf, '\n'); | |
1158 | if (tmp) { | |
1159 | *tmp = '\0'; | |
1160 | size = tmp - kbuf + 1; | |
1161 | } else if (done + size < count) { | |
1162 | pr_warning("Line length is too long: " | |
1163 | "Should be less than %d.", WRITE_BUFSIZE); | |
1164 | ret = -EINVAL; | |
1165 | goto out; | |
1166 | } | |
1167 | done += size; | |
1168 | /* Remove comments */ | |
1169 | tmp = strchr(kbuf, '#'); | |
1170 | if (tmp) | |
1171 | *tmp = '\0'; | |
1172 | ||
1173 | ret = command_trace_probe(kbuf); | |
1174 | if (ret) | |
1175 | goto out; | |
1176 | } | |
1177 | ret = done; | |
1178 | out: | |
1179 | kfree(kbuf); | |
1180 | return ret; | |
1181 | } | |
1182 | ||
1183 | static const struct file_operations kprobe_events_ops = { | |
1184 | .owner = THIS_MODULE, | |
1185 | .open = probes_open, | |
1186 | .read = seq_read, | |
1187 | .llseek = seq_lseek, | |
1188 | .release = seq_release, | |
1189 | .write = probes_write, | |
1190 | }; | |
1191 | ||
cd7e7bd5 MH |
1192 | /* Probes profiling interfaces */ |
1193 | static int probes_profile_seq_show(struct seq_file *m, void *v) | |
1194 | { | |
1195 | struct trace_probe *tp = v; | |
1196 | ||
1197 | seq_printf(m, " %-44s %15lu %15lu\n", tp->call.name, tp->nhit, | |
4a846b44 | 1198 | tp->rp.kp.nmissed); |
cd7e7bd5 MH |
1199 | |
1200 | return 0; | |
1201 | } | |
1202 | ||
1203 | static const struct seq_operations profile_seq_op = { | |
1204 | .start = probes_seq_start, | |
1205 | .next = probes_seq_next, | |
1206 | .stop = probes_seq_stop, | |
1207 | .show = probes_profile_seq_show | |
1208 | }; | |
1209 | ||
1210 | static int profile_open(struct inode *inode, struct file *file) | |
1211 | { | |
1212 | return seq_open(file, &profile_seq_op); | |
1213 | } | |
1214 | ||
1215 | static const struct file_operations kprobe_profile_ops = { | |
1216 | .owner = THIS_MODULE, | |
1217 | .open = profile_open, | |
1218 | .read = seq_read, | |
1219 | .llseek = seq_lseek, | |
1220 | .release = seq_release, | |
1221 | }; | |
1222 | ||
e09c8614 MH |
1223 | /* Sum up total data length for dynamic arraies (strings) */ |
1224 | static __kprobes int __get_data_size(struct trace_probe *tp, | |
1225 | struct pt_regs *regs) | |
1226 | { | |
1227 | int i, ret = 0; | |
1228 | u32 len; | |
1229 | ||
1230 | for (i = 0; i < tp->nr_args; i++) | |
1231 | if (unlikely(tp->args[i].fetch_size.fn)) { | |
1232 | call_fetch(&tp->args[i].fetch_size, regs, &len); | |
1233 | ret += len; | |
1234 | } | |
1235 | ||
1236 | return ret; | |
1237 | } | |
1238 | ||
1239 | /* Store the value of each argument */ | |
1240 | static __kprobes void store_trace_args(int ent_size, struct trace_probe *tp, | |
1241 | struct pt_regs *regs, | |
1242 | u8 *data, int maxlen) | |
1243 | { | |
1244 | int i; | |
1245 | u32 end = tp->size; | |
1246 | u32 *dl; /* Data (relative) location */ | |
1247 | ||
1248 | for (i = 0; i < tp->nr_args; i++) { | |
1249 | if (unlikely(tp->args[i].fetch_size.fn)) { | |
1250 | /* | |
1251 | * First, we set the relative location and | |
1252 | * maximum data length to *dl | |
1253 | */ | |
1254 | dl = (u32 *)(data + tp->args[i].offset); | |
1255 | *dl = make_data_rloc(maxlen, end - tp->args[i].offset); | |
1256 | /* Then try to fetch string or dynamic array data */ | |
1257 | call_fetch(&tp->args[i].fetch, regs, dl); | |
1258 | /* Reduce maximum length */ | |
1259 | end += get_rloc_len(*dl); | |
1260 | maxlen -= get_rloc_len(*dl); | |
1261 | /* Trick here, convert data_rloc to data_loc */ | |
1262 | *dl = convert_rloc_to_loc(*dl, | |
1263 | ent_size + tp->args[i].offset); | |
1264 | } else | |
1265 | /* Just fetching data normally */ | |
1266 | call_fetch(&tp->args[i].fetch, regs, | |
1267 | data + tp->args[i].offset); | |
1268 | } | |
1269 | } | |
1270 | ||
413d37d1 | 1271 | /* Kprobe handler */ |
1e12a4a7 | 1272 | static __kprobes void kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs) |
413d37d1 | 1273 | { |
4a846b44 | 1274 | struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp); |
93ccae7a | 1275 | struct kprobe_trace_entry_head *entry; |
413d37d1 | 1276 | struct ring_buffer_event *event; |
8f8ffe24 | 1277 | struct ring_buffer *buffer; |
e09c8614 | 1278 | int size, dsize, pc; |
413d37d1 | 1279 | unsigned long irq_flags; |
4263565d | 1280 | struct ftrace_event_call *call = &tp->call; |
413d37d1 | 1281 | |
cd7e7bd5 MH |
1282 | tp->nhit++; |
1283 | ||
413d37d1 MH |
1284 | local_save_flags(irq_flags); |
1285 | pc = preempt_count(); | |
1286 | ||
e09c8614 MH |
1287 | dsize = __get_data_size(tp, regs); |
1288 | size = sizeof(*entry) + tp->size + dsize; | |
413d37d1 | 1289 | |
32c0edae SR |
1290 | event = trace_current_buffer_lock_reserve(&buffer, call->event.type, |
1291 | size, irq_flags, pc); | |
413d37d1 | 1292 | if (!event) |
1e12a4a7 | 1293 | return; |
413d37d1 MH |
1294 | |
1295 | entry = ring_buffer_event_data(event); | |
413d37d1 | 1296 | entry->ip = (unsigned long)kp->addr; |
e09c8614 | 1297 | store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize); |
413d37d1 | 1298 | |
8f8ffe24 FW |
1299 | if (!filter_current_check_discard(buffer, call, entry, event)) |
1300 | trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc); | |
413d37d1 MH |
1301 | } |
1302 | ||
1303 | /* Kretprobe handler */ | |
1e12a4a7 | 1304 | static __kprobes void kretprobe_trace_func(struct kretprobe_instance *ri, |
413d37d1 MH |
1305 | struct pt_regs *regs) |
1306 | { | |
1307 | struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp); | |
93ccae7a | 1308 | struct kretprobe_trace_entry_head *entry; |
413d37d1 | 1309 | struct ring_buffer_event *event; |
8f8ffe24 | 1310 | struct ring_buffer *buffer; |
e09c8614 | 1311 | int size, pc, dsize; |
413d37d1 | 1312 | unsigned long irq_flags; |
4263565d | 1313 | struct ftrace_event_call *call = &tp->call; |
413d37d1 MH |
1314 | |
1315 | local_save_flags(irq_flags); | |
1316 | pc = preempt_count(); | |
1317 | ||
e09c8614 MH |
1318 | dsize = __get_data_size(tp, regs); |
1319 | size = sizeof(*entry) + tp->size + dsize; | |
413d37d1 | 1320 | |
32c0edae SR |
1321 | event = trace_current_buffer_lock_reserve(&buffer, call->event.type, |
1322 | size, irq_flags, pc); | |
413d37d1 | 1323 | if (!event) |
1e12a4a7 | 1324 | return; |
413d37d1 MH |
1325 | |
1326 | entry = ring_buffer_event_data(event); | |
4a846b44 | 1327 | entry->func = (unsigned long)tp->rp.kp.addr; |
413d37d1 | 1328 | entry->ret_ip = (unsigned long)ri->ret_addr; |
e09c8614 | 1329 | store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize); |
413d37d1 | 1330 | |
8f8ffe24 FW |
1331 | if (!filter_current_check_discard(buffer, call, entry, event)) |
1332 | trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc); | |
413d37d1 MH |
1333 | } |
1334 | ||
1335 | /* Event entry printers */ | |
1336 | enum print_line_t | |
a9a57763 SR |
1337 | print_kprobe_event(struct trace_iterator *iter, int flags, |
1338 | struct trace_event *event) | |
413d37d1 | 1339 | { |
93ccae7a | 1340 | struct kprobe_trace_entry_head *field; |
413d37d1 | 1341 | struct trace_seq *s = &iter->seq; |
eca0d916 | 1342 | struct trace_probe *tp; |
93ccae7a | 1343 | u8 *data; |
413d37d1 MH |
1344 | int i; |
1345 | ||
93ccae7a | 1346 | field = (struct kprobe_trace_entry_head *)iter->ent; |
80decc70 | 1347 | tp = container_of(event, struct trace_probe, call.event); |
413d37d1 | 1348 | |
6e9f23d1 MH |
1349 | if (!trace_seq_printf(s, "%s: (", tp->call.name)) |
1350 | goto partial; | |
1351 | ||
413d37d1 MH |
1352 | if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET)) |
1353 | goto partial; | |
1354 | ||
6e9f23d1 | 1355 | if (!trace_seq_puts(s, ")")) |
413d37d1 MH |
1356 | goto partial; |
1357 | ||
93ccae7a MH |
1358 | data = (u8 *)&field[1]; |
1359 | for (i = 0; i < tp->nr_args; i++) | |
1360 | if (!tp->args[i].type->print(s, tp->args[i].name, | |
e09c8614 | 1361 | data + tp->args[i].offset, field)) |
413d37d1 MH |
1362 | goto partial; |
1363 | ||
1364 | if (!trace_seq_puts(s, "\n")) | |
1365 | goto partial; | |
1366 | ||
1367 | return TRACE_TYPE_HANDLED; | |
1368 | partial: | |
1369 | return TRACE_TYPE_PARTIAL_LINE; | |
1370 | } | |
1371 | ||
1372 | enum print_line_t | |
a9a57763 SR |
1373 | print_kretprobe_event(struct trace_iterator *iter, int flags, |
1374 | struct trace_event *event) | |
413d37d1 | 1375 | { |
93ccae7a | 1376 | struct kretprobe_trace_entry_head *field; |
413d37d1 | 1377 | struct trace_seq *s = &iter->seq; |
eca0d916 | 1378 | struct trace_probe *tp; |
93ccae7a | 1379 | u8 *data; |
413d37d1 MH |
1380 | int i; |
1381 | ||
93ccae7a | 1382 | field = (struct kretprobe_trace_entry_head *)iter->ent; |
80decc70 | 1383 | tp = container_of(event, struct trace_probe, call.event); |
413d37d1 | 1384 | |
6e9f23d1 MH |
1385 | if (!trace_seq_printf(s, "%s: (", tp->call.name)) |
1386 | goto partial; | |
1387 | ||
413d37d1 MH |
1388 | if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET)) |
1389 | goto partial; | |
1390 | ||
1391 | if (!trace_seq_puts(s, " <- ")) | |
1392 | goto partial; | |
1393 | ||
1394 | if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET)) | |
1395 | goto partial; | |
1396 | ||
6e9f23d1 | 1397 | if (!trace_seq_puts(s, ")")) |
413d37d1 MH |
1398 | goto partial; |
1399 | ||
93ccae7a MH |
1400 | data = (u8 *)&field[1]; |
1401 | for (i = 0; i < tp->nr_args; i++) | |
1402 | if (!tp->args[i].type->print(s, tp->args[i].name, | |
e09c8614 | 1403 | data + tp->args[i].offset, field)) |
413d37d1 MH |
1404 | goto partial; |
1405 | ||
1406 | if (!trace_seq_puts(s, "\n")) | |
1407 | goto partial; | |
1408 | ||
1409 | return TRACE_TYPE_HANDLED; | |
1410 | partial: | |
1411 | return TRACE_TYPE_PARTIAL_LINE; | |
1412 | } | |
1413 | ||
413d37d1 MH |
1414 | static int probe_event_enable(struct ftrace_event_call *call) |
1415 | { | |
1416 | struct trace_probe *tp = (struct trace_probe *)call->data; | |
1417 | ||
50d78056 MH |
1418 | tp->flags |= TP_FLAG_TRACE; |
1419 | if (probe_is_return(tp)) | |
413d37d1 | 1420 | return enable_kretprobe(&tp->rp); |
50d78056 | 1421 | else |
4a846b44 | 1422 | return enable_kprobe(&tp->rp.kp); |
413d37d1 MH |
1423 | } |
1424 | ||
1425 | static void probe_event_disable(struct ftrace_event_call *call) | |
1426 | { | |
1427 | struct trace_probe *tp = (struct trace_probe *)call->data; | |
1428 | ||
50d78056 MH |
1429 | tp->flags &= ~TP_FLAG_TRACE; |
1430 | if (!(tp->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE))) { | |
1431 | if (probe_is_return(tp)) | |
1432 | disable_kretprobe(&tp->rp); | |
1433 | else | |
1434 | disable_kprobe(&tp->rp.kp); | |
1435 | } | |
413d37d1 MH |
1436 | } |
1437 | ||
413d37d1 MH |
1438 | #undef DEFINE_FIELD |
1439 | #define DEFINE_FIELD(type, item, name, is_signed) \ | |
1440 | do { \ | |
1441 | ret = trace_define_field(event_call, #type, name, \ | |
1442 | offsetof(typeof(field), item), \ | |
1443 | sizeof(field.item), is_signed, \ | |
1444 | FILTER_OTHER); \ | |
1445 | if (ret) \ | |
1446 | return ret; \ | |
1447 | } while (0) | |
1448 | ||
1449 | static int kprobe_event_define_fields(struct ftrace_event_call *event_call) | |
1450 | { | |
1451 | int ret, i; | |
93ccae7a | 1452 | struct kprobe_trace_entry_head field; |
413d37d1 MH |
1453 | struct trace_probe *tp = (struct trace_probe *)event_call->data; |
1454 | ||
a703d946 | 1455 | DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0); |
eca0d916 | 1456 | /* Set argument names as fields */ |
93ccae7a | 1457 | for (i = 0; i < tp->nr_args; i++) { |
e09c8614 | 1458 | ret = trace_define_field(event_call, tp->args[i].type->fmttype, |
93ccae7a MH |
1459 | tp->args[i].name, |
1460 | sizeof(field) + tp->args[i].offset, | |
1461 | tp->args[i].type->size, | |
1462 | tp->args[i].type->is_signed, | |
1463 | FILTER_OTHER); | |
1464 | if (ret) | |
1465 | return ret; | |
1466 | } | |
413d37d1 MH |
1467 | return 0; |
1468 | } | |
1469 | ||
1470 | static int kretprobe_event_define_fields(struct ftrace_event_call *event_call) | |
1471 | { | |
1472 | int ret, i; | |
93ccae7a | 1473 | struct kretprobe_trace_entry_head field; |
413d37d1 MH |
1474 | struct trace_probe *tp = (struct trace_probe *)event_call->data; |
1475 | ||
a703d946 MH |
1476 | DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0); |
1477 | DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0); | |
eca0d916 | 1478 | /* Set argument names as fields */ |
93ccae7a | 1479 | for (i = 0; i < tp->nr_args; i++) { |
e09c8614 | 1480 | ret = trace_define_field(event_call, tp->args[i].type->fmttype, |
93ccae7a MH |
1481 | tp->args[i].name, |
1482 | sizeof(field) + tp->args[i].offset, | |
1483 | tp->args[i].type->size, | |
1484 | tp->args[i].type->is_signed, | |
1485 | FILTER_OTHER); | |
1486 | if (ret) | |
1487 | return ret; | |
1488 | } | |
413d37d1 MH |
1489 | return 0; |
1490 | } | |
1491 | ||
a342a028 LJ |
1492 | static int __set_print_fmt(struct trace_probe *tp, char *buf, int len) |
1493 | { | |
1494 | int i; | |
1495 | int pos = 0; | |
1496 | ||
1497 | const char *fmt, *arg; | |
1498 | ||
1499 | if (!probe_is_return(tp)) { | |
1500 | fmt = "(%lx)"; | |
1501 | arg = "REC->" FIELD_STRING_IP; | |
1502 | } else { | |
1503 | fmt = "(%lx <- %lx)"; | |
1504 | arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP; | |
1505 | } | |
1506 | ||
1507 | /* When len=0, we just calculate the needed length */ | |
1508 | #define LEN_OR_ZERO (len ? len - pos : 0) | |
1509 | ||
1510 | pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt); | |
1511 | ||
1512 | for (i = 0; i < tp->nr_args; i++) { | |
93ccae7a MH |
1513 | pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%s", |
1514 | tp->args[i].name, tp->args[i].type->fmt); | |
a342a028 LJ |
1515 | } |
1516 | ||
1517 | pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg); | |
1518 | ||
1519 | for (i = 0; i < tp->nr_args; i++) { | |
e09c8614 MH |
1520 | if (strcmp(tp->args[i].type->name, "string") == 0) |
1521 | pos += snprintf(buf + pos, LEN_OR_ZERO, | |
1522 | ", __get_str(%s)", | |
1523 | tp->args[i].name); | |
1524 | else | |
1525 | pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s", | |
1526 | tp->args[i].name); | |
a342a028 LJ |
1527 | } |
1528 | ||
1529 | #undef LEN_OR_ZERO | |
1530 | ||
1531 | /* return the length of print_fmt */ | |
1532 | return pos; | |
1533 | } | |
1534 | ||
1535 | static int set_print_fmt(struct trace_probe *tp) | |
1536 | { | |
1537 | int len; | |
1538 | char *print_fmt; | |
1539 | ||
1540 | /* First: called with 0 length to calculate the needed length */ | |
1541 | len = __set_print_fmt(tp, NULL, 0); | |
1542 | print_fmt = kmalloc(len + 1, GFP_KERNEL); | |
1543 | if (!print_fmt) | |
1544 | return -ENOMEM; | |
1545 | ||
1546 | /* Second: actually write the @print_fmt */ | |
1547 | __set_print_fmt(tp, print_fmt, len + 1); | |
1548 | tp->call.print_fmt = print_fmt; | |
1549 | ||
1550 | return 0; | |
1551 | } | |
1552 | ||
07b139c8 | 1553 | #ifdef CONFIG_PERF_EVENTS |
e08d1c65 MH |
1554 | |
1555 | /* Kprobe profile handler */ | |
97d5a220 | 1556 | static __kprobes void kprobe_perf_func(struct kprobe *kp, |
e08d1c65 MH |
1557 | struct pt_regs *regs) |
1558 | { | |
1559 | struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp); | |
1560 | struct ftrace_event_call *call = &tp->call; | |
93ccae7a | 1561 | struct kprobe_trace_entry_head *entry; |
1c024eca | 1562 | struct hlist_head *head; |
e09c8614 | 1563 | int size, __size, dsize; |
4ed7c92d | 1564 | int rctx; |
e08d1c65 | 1565 | |
e09c8614 MH |
1566 | dsize = __get_data_size(tp, regs); |
1567 | __size = sizeof(*entry) + tp->size + dsize; | |
74ebb63e MH |
1568 | size = ALIGN(__size + sizeof(u32), sizeof(u64)); |
1569 | size -= sizeof(u32); | |
97d5a220 | 1570 | if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, |
a1a138d0 | 1571 | "profile buffer not large enough")) |
1e12a4a7 | 1572 | return; |
ce71b9df | 1573 | |
ff5f149b | 1574 | entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx); |
430ad5a6 | 1575 | if (!entry) |
1e12a4a7 | 1576 | return; |
a1a138d0 | 1577 | |
a1a138d0 | 1578 | entry->ip = (unsigned long)kp->addr; |
e09c8614 MH |
1579 | memset(&entry[1], 0, dsize); |
1580 | store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize); | |
444a2a3b | 1581 | |
3771f077 | 1582 | head = this_cpu_ptr(call->perf_events); |
1c024eca | 1583 | perf_trace_buf_submit(entry, size, rctx, entry->ip, 1, regs, head); |
e08d1c65 MH |
1584 | } |
1585 | ||
1586 | /* Kretprobe profile handler */ | |
97d5a220 | 1587 | static __kprobes void kretprobe_perf_func(struct kretprobe_instance *ri, |
e08d1c65 MH |
1588 | struct pt_regs *regs) |
1589 | { | |
1590 | struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp); | |
1591 | struct ftrace_event_call *call = &tp->call; | |
93ccae7a | 1592 | struct kretprobe_trace_entry_head *entry; |
1c024eca | 1593 | struct hlist_head *head; |
e09c8614 | 1594 | int size, __size, dsize; |
4ed7c92d | 1595 | int rctx; |
e08d1c65 | 1596 | |
e09c8614 MH |
1597 | dsize = __get_data_size(tp, regs); |
1598 | __size = sizeof(*entry) + tp->size + dsize; | |
74ebb63e MH |
1599 | size = ALIGN(__size + sizeof(u32), sizeof(u64)); |
1600 | size -= sizeof(u32); | |
97d5a220 | 1601 | if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, |
a1a138d0 | 1602 | "profile buffer not large enough")) |
1e12a4a7 | 1603 | return; |
444a2a3b | 1604 | |
ff5f149b | 1605 | entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx); |
430ad5a6 | 1606 | if (!entry) |
1e12a4a7 | 1607 | return; |
e08d1c65 | 1608 | |
a1a138d0 MH |
1609 | entry->func = (unsigned long)tp->rp.kp.addr; |
1610 | entry->ret_ip = (unsigned long)ri->ret_addr; | |
e09c8614 | 1611 | store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize); |
444a2a3b | 1612 | |
3771f077 | 1613 | head = this_cpu_ptr(call->perf_events); |
1c024eca | 1614 | perf_trace_buf_submit(entry, size, rctx, entry->ret_ip, 1, regs, head); |
e08d1c65 MH |
1615 | } |
1616 | ||
97d5a220 | 1617 | static int probe_perf_enable(struct ftrace_event_call *call) |
e08d1c65 MH |
1618 | { |
1619 | struct trace_probe *tp = (struct trace_probe *)call->data; | |
1620 | ||
50d78056 | 1621 | tp->flags |= TP_FLAG_PROFILE; |
d7a4b414 | 1622 | |
50d78056 | 1623 | if (probe_is_return(tp)) |
e08d1c65 | 1624 | return enable_kretprobe(&tp->rp); |
50d78056 | 1625 | else |
e08d1c65 | 1626 | return enable_kprobe(&tp->rp.kp); |
e08d1c65 MH |
1627 | } |
1628 | ||
97d5a220 | 1629 | static void probe_perf_disable(struct ftrace_event_call *call) |
e08d1c65 | 1630 | { |
50d78056 MH |
1631 | struct trace_probe *tp = (struct trace_probe *)call->data; |
1632 | ||
d7a4b414 | 1633 | tp->flags &= ~TP_FLAG_PROFILE; |
50d78056 | 1634 | |
d7a4b414 | 1635 | if (!(tp->flags & TP_FLAG_TRACE)) { |
50d78056 MH |
1636 | if (probe_is_return(tp)) |
1637 | disable_kretprobe(&tp->rp); | |
1638 | else | |
1639 | disable_kprobe(&tp->rp.kp); | |
1640 | } | |
e08d1c65 | 1641 | } |
07b139c8 | 1642 | #endif /* CONFIG_PERF_EVENTS */ |
50d78056 | 1643 | |
2239291a SR |
1644 | static __kprobes |
1645 | int kprobe_register(struct ftrace_event_call *event, enum trace_reg type) | |
1646 | { | |
1647 | switch (type) { | |
1648 | case TRACE_REG_REGISTER: | |
1649 | return probe_event_enable(event); | |
1650 | case TRACE_REG_UNREGISTER: | |
1651 | probe_event_disable(event); | |
1652 | return 0; | |
1653 | ||
1654 | #ifdef CONFIG_PERF_EVENTS | |
1655 | case TRACE_REG_PERF_REGISTER: | |
1656 | return probe_perf_enable(event); | |
1657 | case TRACE_REG_PERF_UNREGISTER: | |
1658 | probe_perf_disable(event); | |
1659 | return 0; | |
1660 | #endif | |
1661 | } | |
1662 | return 0; | |
1663 | } | |
50d78056 MH |
1664 | |
1665 | static __kprobes | |
1666 | int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs) | |
1667 | { | |
1668 | struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp); | |
e08d1c65 | 1669 | |
50d78056 MH |
1670 | if (tp->flags & TP_FLAG_TRACE) |
1671 | kprobe_trace_func(kp, regs); | |
07b139c8 | 1672 | #ifdef CONFIG_PERF_EVENTS |
50d78056 | 1673 | if (tp->flags & TP_FLAG_PROFILE) |
97d5a220 | 1674 | kprobe_perf_func(kp, regs); |
07b139c8 | 1675 | #endif |
50d78056 MH |
1676 | return 0; /* We don't tweek kernel, so just return 0 */ |
1677 | } | |
1678 | ||
1679 | static __kprobes | |
1680 | int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs) | |
1681 | { | |
1682 | struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp); | |
1683 | ||
1684 | if (tp->flags & TP_FLAG_TRACE) | |
1685 | kretprobe_trace_func(ri, regs); | |
07b139c8 | 1686 | #ifdef CONFIG_PERF_EVENTS |
50d78056 | 1687 | if (tp->flags & TP_FLAG_PROFILE) |
97d5a220 | 1688 | kretprobe_perf_func(ri, regs); |
07b139c8 | 1689 | #endif |
50d78056 MH |
1690 | return 0; /* We don't tweek kernel, so just return 0 */ |
1691 | } | |
e08d1c65 | 1692 | |
a9a57763 SR |
1693 | static struct trace_event_functions kretprobe_funcs = { |
1694 | .trace = print_kretprobe_event | |
1695 | }; | |
1696 | ||
1697 | static struct trace_event_functions kprobe_funcs = { | |
1698 | .trace = print_kprobe_event | |
1699 | }; | |
1700 | ||
413d37d1 MH |
1701 | static int register_probe_event(struct trace_probe *tp) |
1702 | { | |
1703 | struct ftrace_event_call *call = &tp->call; | |
1704 | int ret; | |
1705 | ||
1706 | /* Initialize ftrace_event_call */ | |
ffb9f995 | 1707 | INIT_LIST_HEAD(&call->class->fields); |
413d37d1 | 1708 | if (probe_is_return(tp)) { |
80decc70 | 1709 | call->event.funcs = &kretprobe_funcs; |
2e33af02 | 1710 | call->class->define_fields = kretprobe_event_define_fields; |
413d37d1 | 1711 | } else { |
80decc70 | 1712 | call->event.funcs = &kprobe_funcs; |
2e33af02 | 1713 | call->class->define_fields = kprobe_event_define_fields; |
413d37d1 | 1714 | } |
a342a028 LJ |
1715 | if (set_print_fmt(tp) < 0) |
1716 | return -ENOMEM; | |
32c0edae SR |
1717 | ret = register_ftrace_event(&call->event); |
1718 | if (!ret) { | |
a342a028 | 1719 | kfree(call->print_fmt); |
ff50d991 | 1720 | return -ENODEV; |
a342a028 | 1721 | } |
553552ce | 1722 | call->flags = 0; |
2239291a | 1723 | call->class->reg = kprobe_register; |
413d37d1 MH |
1724 | call->data = tp; |
1725 | ret = trace_add_event_call(call); | |
ff50d991 | 1726 | if (ret) { |
413d37d1 | 1727 | pr_info("Failed to register kprobe event: %s\n", call->name); |
a342a028 | 1728 | kfree(call->print_fmt); |
80decc70 | 1729 | unregister_ftrace_event(&call->event); |
ff50d991 | 1730 | } |
413d37d1 MH |
1731 | return ret; |
1732 | } | |
1733 | ||
1734 | static void unregister_probe_event(struct trace_probe *tp) | |
1735 | { | |
ff50d991 | 1736 | /* tp->event is unregistered in trace_remove_event_call() */ |
413d37d1 | 1737 | trace_remove_event_call(&tp->call); |
a342a028 | 1738 | kfree(tp->call.print_fmt); |
413d37d1 MH |
1739 | } |
1740 | ||
1741 | /* Make a debugfs interface for controling probe points */ | |
1742 | static __init int init_kprobe_trace(void) | |
1743 | { | |
1744 | struct dentry *d_tracer; | |
1745 | struct dentry *entry; | |
413d37d1 MH |
1746 | |
1747 | d_tracer = tracing_init_dentry(); | |
1748 | if (!d_tracer) | |
1749 | return 0; | |
1750 | ||
1751 | entry = debugfs_create_file("kprobe_events", 0644, d_tracer, | |
1752 | NULL, &kprobe_events_ops); | |
1753 | ||
cd7e7bd5 | 1754 | /* Event list interface */ |
413d37d1 MH |
1755 | if (!entry) |
1756 | pr_warning("Could not create debugfs " | |
1757 | "'kprobe_events' entry\n"); | |
cd7e7bd5 MH |
1758 | |
1759 | /* Profile interface */ | |
1760 | entry = debugfs_create_file("kprobe_profile", 0444, d_tracer, | |
1761 | NULL, &kprobe_profile_ops); | |
1762 | ||
1763 | if (!entry) | |
1764 | pr_warning("Could not create debugfs " | |
1765 | "'kprobe_profile' entry\n"); | |
413d37d1 MH |
1766 | return 0; |
1767 | } | |
1768 | fs_initcall(init_kprobe_trace); | |
1769 | ||
1770 | ||
1771 | #ifdef CONFIG_FTRACE_STARTUP_TEST | |
1772 | ||
1773 | static int kprobe_trace_selftest_target(int a1, int a2, int a3, | |
1774 | int a4, int a5, int a6) | |
1775 | { | |
1776 | return a1 + a2 + a3 + a4 + a5 + a6; | |
1777 | } | |
1778 | ||
1779 | static __init int kprobe_trace_self_tests_init(void) | |
1780 | { | |
231e36f4 | 1781 | int ret, warn = 0; |
413d37d1 | 1782 | int (*target)(int, int, int, int, int, int); |
231e36f4 | 1783 | struct trace_probe *tp; |
413d37d1 MH |
1784 | |
1785 | target = kprobe_trace_selftest_target; | |
1786 | ||
1787 | pr_info("Testing kprobe tracing: "); | |
1788 | ||
1789 | ret = command_trace_probe("p:testprobe kprobe_trace_selftest_target " | |
231e36f4 MH |
1790 | "$stack $stack0 +0($stack)"); |
1791 | if (WARN_ON_ONCE(ret)) { | |
1792 | pr_warning("error on probing function entry.\n"); | |
1793 | warn++; | |
1794 | } else { | |
1795 | /* Enable trace point */ | |
1796 | tp = find_probe_event("testprobe", KPROBE_EVENT_SYSTEM); | |
1797 | if (WARN_ON_ONCE(tp == NULL)) { | |
1798 | pr_warning("error on getting new probe.\n"); | |
1799 | warn++; | |
1800 | } else | |
1801 | probe_event_enable(&tp->call); | |
1802 | } | |
413d37d1 MH |
1803 | |
1804 | ret = command_trace_probe("r:testprobe2 kprobe_trace_selftest_target " | |
f397af06 | 1805 | "$retval"); |
231e36f4 MH |
1806 | if (WARN_ON_ONCE(ret)) { |
1807 | pr_warning("error on probing function return.\n"); | |
1808 | warn++; | |
1809 | } else { | |
1810 | /* Enable trace point */ | |
1811 | tp = find_probe_event("testprobe2", KPROBE_EVENT_SYSTEM); | |
1812 | if (WARN_ON_ONCE(tp == NULL)) { | |
1813 | pr_warning("error on getting new probe.\n"); | |
1814 | warn++; | |
1815 | } else | |
1816 | probe_event_enable(&tp->call); | |
1817 | } | |
1818 | ||
1819 | if (warn) | |
1820 | goto end; | |
413d37d1 MH |
1821 | |
1822 | ret = target(1, 2, 3, 4, 5, 6); | |
1823 | ||
231e36f4 MH |
1824 | ret = command_trace_probe("-:testprobe"); |
1825 | if (WARN_ON_ONCE(ret)) { | |
1826 | pr_warning("error on deleting a probe.\n"); | |
1827 | warn++; | |
1828 | } | |
1829 | ||
1830 | ret = command_trace_probe("-:testprobe2"); | |
1831 | if (WARN_ON_ONCE(ret)) { | |
1832 | pr_warning("error on deleting a probe.\n"); | |
1833 | warn++; | |
1834 | } | |
413d37d1 | 1835 | |
231e36f4 MH |
1836 | end: |
1837 | cleanup_all_probes(); | |
1838 | if (warn) | |
1839 | pr_cont("NG: Some tests are failed. Please check them.\n"); | |
1840 | else | |
1841 | pr_cont("OK\n"); | |
413d37d1 MH |
1842 | return 0; |
1843 | } | |
1844 | ||
1845 | late_initcall(kprobe_trace_self_tests_init); | |
1846 | ||
1847 | #endif |