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8ab83f56 SD |
1 | /* |
2 | * Common header file 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.h 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 | */ | |
24 | ||
25 | #include <linux/seq_file.h> | |
26 | #include <linux/slab.h> | |
27 | #include <linux/smp.h> | |
28 | #include <linux/debugfs.h> | |
29 | #include <linux/types.h> | |
30 | #include <linux/string.h> | |
31 | #include <linux/ctype.h> | |
32 | #include <linux/ptrace.h> | |
33 | #include <linux/perf_event.h> | |
34 | #include <linux/kprobes.h> | |
35 | #include <linux/stringify.h> | |
36 | #include <linux/limits.h> | |
37 | #include <linux/uaccess.h> | |
38 | #include <asm/bitsperlong.h> | |
39 | ||
40 | #include "trace.h" | |
41 | #include "trace_output.h" | |
42 | ||
43 | #define MAX_TRACE_ARGS 128 | |
44 | #define MAX_ARGSTR_LEN 63 | |
45 | #define MAX_EVENT_NAME_LEN 64 | |
46 | #define MAX_STRING_SIZE PATH_MAX | |
47 | ||
48 | /* Reserved field names */ | |
49 | #define FIELD_STRING_IP "__probe_ip" | |
50 | #define FIELD_STRING_RETIP "__probe_ret_ip" | |
51 | #define FIELD_STRING_FUNC "__probe_func" | |
52 | ||
53 | #undef DEFINE_FIELD | |
54 | #define DEFINE_FIELD(type, item, name, is_signed) \ | |
55 | do { \ | |
56 | ret = trace_define_field(event_call, #type, name, \ | |
57 | offsetof(typeof(field), item), \ | |
58 | sizeof(field.item), is_signed, \ | |
59 | FILTER_OTHER); \ | |
60 | if (ret) \ | |
61 | return ret; \ | |
62 | } while (0) | |
63 | ||
64 | ||
65 | /* Flags for trace_probe */ | |
66 | #define TP_FLAG_TRACE 1 | |
67 | #define TP_FLAG_PROFILE 2 | |
68 | #define TP_FLAG_REGISTERED 4 | |
69 | ||
70 | ||
71 | /* data_rloc: data relative location, compatible with u32 */ | |
72 | #define make_data_rloc(len, roffs) \ | |
73 | (((u32)(len) << 16) | ((u32)(roffs) & 0xffff)) | |
74 | #define get_rloc_len(dl) ((u32)(dl) >> 16) | |
75 | #define get_rloc_offs(dl) ((u32)(dl) & 0xffff) | |
76 | ||
77 | /* | |
78 | * Convert data_rloc to data_loc: | |
79 | * data_rloc stores the offset from data_rloc itself, but data_loc | |
80 | * stores the offset from event entry. | |
81 | */ | |
82 | #define convert_rloc_to_loc(dl, offs) ((u32)(dl) + (offs)) | |
83 | ||
3da0f180 | 84 | static nokprobe_inline void *get_rloc_data(u32 *dl) |
b26c74e1 NK |
85 | { |
86 | return (u8 *)dl + get_rloc_offs(*dl); | |
87 | } | |
88 | ||
89 | /* For data_loc conversion */ | |
3da0f180 | 90 | static nokprobe_inline void *get_loc_data(u32 *dl, void *ent) |
b26c74e1 NK |
91 | { |
92 | return (u8 *)ent + get_rloc_offs(*dl); | |
93 | } | |
94 | ||
8ab83f56 SD |
95 | /* Data fetch function type */ |
96 | typedef void (*fetch_func_t)(struct pt_regs *, void *, void *); | |
97 | /* Printing function type */ | |
98 | typedef int (*print_type_func_t)(struct trace_seq *, const char *, void *, void *); | |
99 | ||
100 | /* Fetch types */ | |
101 | enum { | |
102 | FETCH_MTD_reg = 0, | |
103 | FETCH_MTD_stack, | |
104 | FETCH_MTD_retval, | |
105 | FETCH_MTD_memory, | |
106 | FETCH_MTD_symbol, | |
107 | FETCH_MTD_deref, | |
108 | FETCH_MTD_bitfield, | |
b7e0bf34 | 109 | FETCH_MTD_file_offset, |
8ab83f56 SD |
110 | FETCH_MTD_END, |
111 | }; | |
112 | ||
113 | /* Fetch type information table */ | |
114 | struct fetch_type { | |
115 | const char *name; /* Name of type */ | |
116 | size_t size; /* Byte size of type */ | |
117 | int is_signed; /* Signed flag */ | |
118 | print_type_func_t print; /* Print functions */ | |
119 | const char *fmt; /* Fromat string */ | |
120 | const char *fmttype; /* Name in format file */ | |
121 | /* Fetch functions */ | |
122 | fetch_func_t fetch[FETCH_MTD_END]; | |
123 | }; | |
124 | ||
125 | struct fetch_param { | |
126 | fetch_func_t fn; | |
127 | void *data; | |
128 | }; | |
129 | ||
34fee3a1 NK |
130 | /* For defining macros, define string/string_size types */ |
131 | typedef u32 string; | |
132 | typedef u32 string_size; | |
133 | ||
b26c74e1 NK |
134 | #define PRINT_TYPE_FUNC_NAME(type) print_type_##type |
135 | #define PRINT_TYPE_FMT_NAME(type) print_type_format_##type | |
136 | ||
137 | /* Printing in basic type function template */ | |
138 | #define DECLARE_BASIC_PRINT_TYPE_FUNC(type) \ | |
3da0f180 MH |
139 | int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, const char *name, \ |
140 | void *data, void *ent); \ | |
b26c74e1 NK |
141 | extern const char PRINT_TYPE_FMT_NAME(type)[] |
142 | ||
143 | DECLARE_BASIC_PRINT_TYPE_FUNC(u8); | |
144 | DECLARE_BASIC_PRINT_TYPE_FUNC(u16); | |
145 | DECLARE_BASIC_PRINT_TYPE_FUNC(u32); | |
146 | DECLARE_BASIC_PRINT_TYPE_FUNC(u64); | |
147 | DECLARE_BASIC_PRINT_TYPE_FUNC(s8); | |
148 | DECLARE_BASIC_PRINT_TYPE_FUNC(s16); | |
149 | DECLARE_BASIC_PRINT_TYPE_FUNC(s32); | |
150 | DECLARE_BASIC_PRINT_TYPE_FUNC(s64); | |
151 | DECLARE_BASIC_PRINT_TYPE_FUNC(string); | |
152 | ||
34fee3a1 NK |
153 | #define FETCH_FUNC_NAME(method, type) fetch_##method##_##type |
154 | ||
155 | /* Declare macro for basic types */ | |
156 | #define DECLARE_FETCH_FUNC(method, type) \ | |
157 | extern void FETCH_FUNC_NAME(method, type)(struct pt_regs *regs, \ | |
158 | void *data, void *dest) | |
159 | ||
160 | #define DECLARE_BASIC_FETCH_FUNCS(method) \ | |
161 | DECLARE_FETCH_FUNC(method, u8); \ | |
162 | DECLARE_FETCH_FUNC(method, u16); \ | |
163 | DECLARE_FETCH_FUNC(method, u32); \ | |
164 | DECLARE_FETCH_FUNC(method, u64) | |
165 | ||
166 | DECLARE_BASIC_FETCH_FUNCS(reg); | |
167 | #define fetch_reg_string NULL | |
168 | #define fetch_reg_string_size NULL | |
169 | ||
34fee3a1 NK |
170 | DECLARE_BASIC_FETCH_FUNCS(retval); |
171 | #define fetch_retval_string NULL | |
172 | #define fetch_retval_string_size NULL | |
173 | ||
34fee3a1 NK |
174 | DECLARE_BASIC_FETCH_FUNCS(symbol); |
175 | DECLARE_FETCH_FUNC(symbol, string); | |
176 | DECLARE_FETCH_FUNC(symbol, string_size); | |
177 | ||
178 | DECLARE_BASIC_FETCH_FUNCS(deref); | |
179 | DECLARE_FETCH_FUNC(deref, string); | |
180 | DECLARE_FETCH_FUNC(deref, string_size); | |
181 | ||
182 | DECLARE_BASIC_FETCH_FUNCS(bitfield); | |
183 | #define fetch_bitfield_string NULL | |
184 | #define fetch_bitfield_string_size NULL | |
185 | ||
3fd996a2 NK |
186 | /* |
187 | * Define macro for basic types - we don't need to define s* types, because | |
188 | * we have to care only about bitwidth at recording time. | |
189 | */ | |
190 | #define DEFINE_BASIC_FETCH_FUNCS(method) \ | |
191 | DEFINE_FETCH_##method(u8) \ | |
192 | DEFINE_FETCH_##method(u16) \ | |
193 | DEFINE_FETCH_##method(u32) \ | |
194 | DEFINE_FETCH_##method(u64) | |
195 | ||
b26c74e1 NK |
196 | /* Default (unsigned long) fetch type */ |
197 | #define __DEFAULT_FETCH_TYPE(t) u##t | |
198 | #define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t) | |
199 | #define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG) | |
200 | #define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE) | |
201 | ||
202 | #define ASSIGN_FETCH_FUNC(method, type) \ | |
203 | [FETCH_MTD_##method] = FETCH_FUNC_NAME(method, type) | |
204 | ||
205 | #define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \ | |
206 | {.name = _name, \ | |
207 | .size = _size, \ | |
208 | .is_signed = sign, \ | |
209 | .print = PRINT_TYPE_FUNC_NAME(ptype), \ | |
210 | .fmt = PRINT_TYPE_FMT_NAME(ptype), \ | |
211 | .fmttype = _fmttype, \ | |
212 | .fetch = { \ | |
213 | ASSIGN_FETCH_FUNC(reg, ftype), \ | |
214 | ASSIGN_FETCH_FUNC(stack, ftype), \ | |
215 | ASSIGN_FETCH_FUNC(retval, ftype), \ | |
216 | ASSIGN_FETCH_FUNC(memory, ftype), \ | |
217 | ASSIGN_FETCH_FUNC(symbol, ftype), \ | |
218 | ASSIGN_FETCH_FUNC(deref, ftype), \ | |
219 | ASSIGN_FETCH_FUNC(bitfield, ftype), \ | |
b7e0bf34 | 220 | ASSIGN_FETCH_FUNC(file_offset, ftype), \ |
b26c74e1 NK |
221 | } \ |
222 | } | |
223 | ||
224 | #define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \ | |
225 | __ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #ptype) | |
226 | ||
34fee3a1 NK |
227 | #define ASSIGN_FETCH_TYPE_END {} |
228 | ||
b26c74e1 NK |
229 | #define FETCH_TYPE_STRING 0 |
230 | #define FETCH_TYPE_STRSIZE 1 | |
231 | ||
34fee3a1 NK |
232 | /* |
233 | * Fetch type information table. | |
234 | * It's declared as a weak symbol due to conditional compilation. | |
235 | */ | |
236 | extern __weak const struct fetch_type kprobes_fetch_type_table[]; | |
237 | extern __weak const struct fetch_type uprobes_fetch_type_table[]; | |
b26c74e1 | 238 | |
1301a44e NK |
239 | #ifdef CONFIG_KPROBE_EVENT |
240 | struct symbol_cache; | |
241 | unsigned long update_symbol_cache(struct symbol_cache *sc); | |
242 | void free_symbol_cache(struct symbol_cache *sc); | |
243 | struct symbol_cache *alloc_symbol_cache(const char *sym, long offset); | |
244 | #else | |
e0d18fe0 NK |
245 | /* uprobes do not support symbol fetch methods */ |
246 | #define fetch_symbol_u8 NULL | |
247 | #define fetch_symbol_u16 NULL | |
248 | #define fetch_symbol_u32 NULL | |
249 | #define fetch_symbol_u64 NULL | |
250 | #define fetch_symbol_string NULL | |
251 | #define fetch_symbol_string_size NULL | |
252 | ||
1301a44e NK |
253 | struct symbol_cache { |
254 | }; | |
255 | static inline unsigned long __used update_symbol_cache(struct symbol_cache *sc) | |
256 | { | |
257 | return 0; | |
258 | } | |
259 | ||
260 | static inline void __used free_symbol_cache(struct symbol_cache *sc) | |
261 | { | |
262 | } | |
263 | ||
264 | static inline struct symbol_cache * __used | |
265 | alloc_symbol_cache(const char *sym, long offset) | |
266 | { | |
267 | return NULL; | |
268 | } | |
269 | #endif /* CONFIG_KPROBE_EVENT */ | |
270 | ||
8ab83f56 SD |
271 | struct probe_arg { |
272 | struct fetch_param fetch; | |
273 | struct fetch_param fetch_size; | |
274 | unsigned int offset; /* Offset from argument entry */ | |
275 | const char *name; /* Name of this argument */ | |
276 | const char *comm; /* Command of this argument */ | |
277 | const struct fetch_type *type; /* Type of this argument */ | |
278 | }; | |
279 | ||
c31ffb3f NK |
280 | struct trace_probe { |
281 | unsigned int flags; /* For TP_FLAG_* */ | |
282 | struct ftrace_event_class class; | |
283 | struct ftrace_event_call call; | |
284 | struct list_head files; | |
285 | ssize_t size; /* trace entry size */ | |
286 | unsigned int nr_args; | |
287 | struct probe_arg args[]; | |
288 | }; | |
289 | ||
70ed91c6 J |
290 | struct event_file_link { |
291 | struct ftrace_event_file *file; | |
292 | struct list_head list; | |
293 | }; | |
294 | ||
c31ffb3f NK |
295 | static inline bool trace_probe_is_enabled(struct trace_probe *tp) |
296 | { | |
297 | return !!(tp->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE)); | |
298 | } | |
299 | ||
300 | static inline bool trace_probe_is_registered(struct trace_probe *tp) | |
301 | { | |
302 | return !!(tp->flags & TP_FLAG_REGISTERED); | |
303 | } | |
304 | ||
3da0f180 | 305 | static nokprobe_inline void call_fetch(struct fetch_param *fprm, |
8ab83f56 SD |
306 | struct pt_regs *regs, void *dest) |
307 | { | |
308 | return fprm->fn(regs, fprm->data, dest); | |
309 | } | |
310 | ||
311 | /* Check the name is good for event/group/fields */ | |
312 | static inline int is_good_name(const char *name) | |
313 | { | |
314 | if (!isalpha(*name) && *name != '_') | |
315 | return 0; | |
316 | while (*++name != '\0') { | |
317 | if (!isalpha(*name) && !isdigit(*name) && *name != '_') | |
318 | return 0; | |
319 | } | |
320 | return 1; | |
321 | } | |
322 | ||
70ed91c6 J |
323 | static inline struct event_file_link * |
324 | find_event_file_link(struct trace_probe *tp, struct ftrace_event_file *file) | |
325 | { | |
326 | struct event_file_link *link; | |
327 | ||
328 | list_for_each_entry(link, &tp->files, list) | |
329 | if (link->file == file) | |
330 | return link; | |
331 | ||
332 | return NULL; | |
333 | } | |
334 | ||
8ab83f56 | 335 | extern int traceprobe_parse_probe_arg(char *arg, ssize_t *size, |
f3f096cf | 336 | struct probe_arg *parg, bool is_return, bool is_kprobe); |
8ab83f56 SD |
337 | |
338 | extern int traceprobe_conflict_field_name(const char *name, | |
339 | struct probe_arg *args, int narg); | |
340 | ||
341 | extern void traceprobe_update_arg(struct probe_arg *arg); | |
342 | extern void traceprobe_free_probe_arg(struct probe_arg *arg); | |
343 | ||
344 | extern int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset); | |
345 | ||
346 | extern ssize_t traceprobe_probes_write(struct file *file, | |
347 | const char __user *buffer, size_t count, loff_t *ppos, | |
348 | int (*createfn)(int, char**)); | |
349 | ||
350 | extern int traceprobe_command(const char *buf, int (*createfn)(int, char**)); | |
2dc10183 NK |
351 | |
352 | /* Sum up total data length for dynamic arraies (strings) */ | |
3da0f180 | 353 | static nokprobe_inline int |
2dc10183 NK |
354 | __get_data_size(struct trace_probe *tp, struct pt_regs *regs) |
355 | { | |
356 | int i, ret = 0; | |
357 | u32 len; | |
358 | ||
359 | for (i = 0; i < tp->nr_args; i++) | |
360 | if (unlikely(tp->args[i].fetch_size.fn)) { | |
361 | call_fetch(&tp->args[i].fetch_size, regs, &len); | |
362 | ret += len; | |
363 | } | |
364 | ||
365 | return ret; | |
366 | } | |
367 | ||
368 | /* Store the value of each argument */ | |
3da0f180 | 369 | static nokprobe_inline void |
2dc10183 NK |
370 | store_trace_args(int ent_size, struct trace_probe *tp, struct pt_regs *regs, |
371 | u8 *data, int maxlen) | |
372 | { | |
373 | int i; | |
374 | u32 end = tp->size; | |
375 | u32 *dl; /* Data (relative) location */ | |
376 | ||
377 | for (i = 0; i < tp->nr_args; i++) { | |
378 | if (unlikely(tp->args[i].fetch_size.fn)) { | |
379 | /* | |
380 | * First, we set the relative location and | |
381 | * maximum data length to *dl | |
382 | */ | |
383 | dl = (u32 *)(data + tp->args[i].offset); | |
384 | *dl = make_data_rloc(maxlen, end - tp->args[i].offset); | |
385 | /* Then try to fetch string or dynamic array data */ | |
386 | call_fetch(&tp->args[i].fetch, regs, dl); | |
387 | /* Reduce maximum length */ | |
388 | end += get_rloc_len(*dl); | |
389 | maxlen -= get_rloc_len(*dl); | |
390 | /* Trick here, convert data_rloc to data_loc */ | |
391 | *dl = convert_rloc_to_loc(*dl, | |
392 | ent_size + tp->args[i].offset); | |
393 | } else | |
394 | /* Just fetching data normally */ | |
395 | call_fetch(&tp->args[i].fetch, regs, | |
396 | data + tp->args[i].offset); | |
397 | } | |
398 | } | |
5bf652aa NK |
399 | |
400 | extern int set_print_fmt(struct trace_probe *tp, bool is_return); |