1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Common header file for probe-based Dynamic events.
4 *
5 * This code was copied from kernel/trace/trace_kprobe.h written by
6 * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
7 *
8 * Updates to make this generic:
9 * Copyright (C) IBM Corporation, 2010-2011
10 * Author: Srikar Dronamraju
11 */
12
13 #include <linux/seq_file.h>
14 #include <linux/slab.h>
15 #include <linux/smp.h>
16 #include <linux/tracefs.h>
17 #include <linux/types.h>
18 #include <linux/string.h>
19 #include <linux/ctype.h>
20 #include <linux/ptrace.h>
21 #include <linux/perf_event.h>
22 #include <linux/kprobes.h>
23 #include <linux/stringify.h>
24 #include <linux/limits.h>
25 #include <linux/uaccess.h>
26 #include <linux/bitops.h>
27 #include <asm/bitsperlong.h>
28
29 #include "trace.h"
30 #include "trace_output.h"
31
32 #define MAX_TRACE_ARGS 128
33 #define MAX_ARGSTR_LEN 63
34 #define MAX_ARRAY_LEN 64
35 #define MAX_ARG_NAME_LEN 32
36 #define MAX_STRING_SIZE PATH_MAX
37
38 /* Reserved field names */
39 #define FIELD_STRING_IP "__probe_ip"
40 #define FIELD_STRING_RETIP "__probe_ret_ip"
41 #define FIELD_STRING_FUNC "__probe_func"
42
43 #undef DEFINE_FIELD
44 #define DEFINE_FIELD(type, item, name, is_signed) \
45 do { \
46 ret = trace_define_field(event_call, #type, name, \
47 offsetof(typeof(field), item), \
48 sizeof(field.item), is_signed, \
49 FILTER_OTHER); \
50 if (ret) \
51 return ret; \
52 } while (0)
53
54
55 /* Flags for trace_probe */
56 #define TP_FLAG_TRACE 1
57 #define TP_FLAG_PROFILE 2
58
59 /* data_loc: data location, compatible with u32 */
60 #define make_data_loc(len, offs) \
61 (((u32)(len) << 16) | ((u32)(offs) & 0xffff))
62 #define get_loc_len(dl) ((u32)(dl) >> 16)
63 #define get_loc_offs(dl) ((u32)(dl) & 0xffff)
64
get_loc_data(u32 * dl,void * ent)65 static nokprobe_inline void *get_loc_data(u32 *dl, void *ent)
66 {
67 return (u8 *)ent + get_loc_offs(*dl);
68 }
69
update_data_loc(u32 loc,int consumed)70 static nokprobe_inline u32 update_data_loc(u32 loc, int consumed)
71 {
72 u32 maxlen = get_loc_len(loc);
73 u32 offset = get_loc_offs(loc);
74
75 return make_data_loc(maxlen - consumed, offset + consumed);
76 }
77
78 /* Printing function type */
79 typedef int (*print_type_func_t)(struct trace_seq *, void *, void *);
80
81 enum fetch_op {
82 FETCH_OP_NOP = 0,
83 // Stage 1 (load) ops
84 FETCH_OP_REG, /* Register : .param = offset */
85 FETCH_OP_STACK, /* Stack : .param = index */
86 FETCH_OP_STACKP, /* Stack pointer */
87 FETCH_OP_RETVAL, /* Return value */
88 FETCH_OP_IMM, /* Immediate : .immediate */
89 FETCH_OP_COMM, /* Current comm */
90 FETCH_OP_ARG, /* Function argument : .param */
91 FETCH_OP_FOFFS, /* File offset: .immediate */
92 FETCH_OP_DATA, /* Allocated data: .data */
93 // Stage 2 (dereference) op
94 FETCH_OP_DEREF, /* Dereference: .offset */
95 FETCH_OP_UDEREF, /* User-space Dereference: .offset */
96 // Stage 3 (store) ops
97 FETCH_OP_ST_RAW, /* Raw: .size */
98 FETCH_OP_ST_MEM, /* Mem: .offset, .size */
99 FETCH_OP_ST_UMEM, /* Mem: .offset, .size */
100 FETCH_OP_ST_STRING, /* String: .offset, .size */
101 FETCH_OP_ST_USTRING, /* User String: .offset, .size */
102 // Stage 4 (modify) op
103 FETCH_OP_MOD_BF, /* Bitfield: .basesize, .lshift, .rshift */
104 // Stage 5 (loop) op
105 FETCH_OP_LP_ARRAY, /* Array: .param = loop count */
106 FETCH_OP_END,
107 FETCH_NOP_SYMBOL, /* Unresolved Symbol holder */
108 };
109
110 struct fetch_insn {
111 enum fetch_op op;
112 union {
113 unsigned int param;
114 struct {
115 unsigned int size;
116 int offset;
117 };
118 struct {
119 unsigned char basesize;
120 unsigned char lshift;
121 unsigned char rshift;
122 };
123 unsigned long immediate;
124 void *data;
125 };
126 };
127
128 /* fetch + deref*N + store + mod + end <= 16, this allows N=12, enough */
129 #define FETCH_INSN_MAX 16
130 #define FETCH_TOKEN_COMM (-ECOMM)
131
132 /* Fetch type information table */
133 struct fetch_type {
134 const char *name; /* Name of type */
135 size_t size; /* Byte size of type */
136 int is_signed; /* Signed flag */
137 print_type_func_t print; /* Print functions */
138 const char *fmt; /* Fromat string */
139 const char *fmttype; /* Name in format file */
140 };
141
142 /* For defining macros, define string/string_size types */
143 typedef u32 string;
144 typedef u32 string_size;
145
146 #define PRINT_TYPE_FUNC_NAME(type) print_type_##type
147 #define PRINT_TYPE_FMT_NAME(type) print_type_format_##type
148
149 /* Printing in basic type function template */
150 #define DECLARE_BASIC_PRINT_TYPE_FUNC(type) \
151 int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, void *data, void *ent);\
152 extern const char PRINT_TYPE_FMT_NAME(type)[]
153
154 DECLARE_BASIC_PRINT_TYPE_FUNC(u8);
155 DECLARE_BASIC_PRINT_TYPE_FUNC(u16);
156 DECLARE_BASIC_PRINT_TYPE_FUNC(u32);
157 DECLARE_BASIC_PRINT_TYPE_FUNC(u64);
158 DECLARE_BASIC_PRINT_TYPE_FUNC(s8);
159 DECLARE_BASIC_PRINT_TYPE_FUNC(s16);
160 DECLARE_BASIC_PRINT_TYPE_FUNC(s32);
161 DECLARE_BASIC_PRINT_TYPE_FUNC(s64);
162 DECLARE_BASIC_PRINT_TYPE_FUNC(x8);
163 DECLARE_BASIC_PRINT_TYPE_FUNC(x16);
164 DECLARE_BASIC_PRINT_TYPE_FUNC(x32);
165 DECLARE_BASIC_PRINT_TYPE_FUNC(x64);
166
167 DECLARE_BASIC_PRINT_TYPE_FUNC(string);
168 DECLARE_BASIC_PRINT_TYPE_FUNC(symbol);
169
170 /* Default (unsigned long) fetch type */
171 #define __DEFAULT_FETCH_TYPE(t) x##t
172 #define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t)
173 #define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG)
174 #define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE)
175
176 #define __ADDR_FETCH_TYPE(t) u##t
177 #define _ADDR_FETCH_TYPE(t) __ADDR_FETCH_TYPE(t)
178 #define ADDR_FETCH_TYPE _ADDR_FETCH_TYPE(BITS_PER_LONG)
179
180 #define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \
181 {.name = _name, \
182 .size = _size, \
183 .is_signed = sign, \
184 .print = PRINT_TYPE_FUNC_NAME(ptype), \
185 .fmt = PRINT_TYPE_FMT_NAME(ptype), \
186 .fmttype = _fmttype, \
187 }
188 #define _ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \
189 __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, #_fmttype)
190 #define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \
191 _ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, ptype)
192
193 /* If ptype is an alias of atype, use this macro (show atype in format) */
194 #define ASSIGN_FETCH_TYPE_ALIAS(ptype, atype, ftype, sign) \
195 _ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, atype)
196
197 #define ASSIGN_FETCH_TYPE_END {}
198 #define MAX_ARRAY_LEN 64
199
200 #ifdef CONFIG_KPROBE_EVENTS
201 bool trace_kprobe_on_func_entry(struct trace_event_call *call);
202 bool trace_kprobe_error_injectable(struct trace_event_call *call);
203 #else
trace_kprobe_on_func_entry(struct trace_event_call * call)204 static inline bool trace_kprobe_on_func_entry(struct trace_event_call *call)
205 {
206 return false;
207 }
208
trace_kprobe_error_injectable(struct trace_event_call * call)209 static inline bool trace_kprobe_error_injectable(struct trace_event_call *call)
210 {
211 return false;
212 }
213 #endif /* CONFIG_KPROBE_EVENTS */
214
215 struct probe_arg {
216 struct fetch_insn *code;
217 bool dynamic;/* Dynamic array (string) is used */
218 unsigned int offset; /* Offset from argument entry */
219 unsigned int count; /* Array count */
220 const char *name; /* Name of this argument */
221 const char *comm; /* Command of this argument */
222 char *fmt; /* Format string if needed */
223 const struct fetch_type *type; /* Type of this argument */
224 };
225
226 /* Event call and class holder */
227 struct trace_probe_event {
228 unsigned int flags; /* For TP_FLAG_* */
229 struct trace_event_class class;
230 struct trace_event_call call;
231 struct list_head files;
232 struct list_head probes;
233 char data[0];
234 };
235
236 struct trace_probe {
237 struct list_head list;
238 struct trace_probe_event *event;
239 ssize_t size; /* trace entry size */
240 unsigned int nr_args;
241 struct probe_arg args[];
242 };
243
244 struct event_file_link {
245 struct trace_event_file *file;
246 struct list_head list;
247 };
248
trace_probe_test_flag(struct trace_probe * tp,unsigned int flag)249 static inline bool trace_probe_test_flag(struct trace_probe *tp,
250 unsigned int flag)
251 {
252 return !!(tp->event->flags & flag);
253 }
254
trace_probe_set_flag(struct trace_probe * tp,unsigned int flag)255 static inline void trace_probe_set_flag(struct trace_probe *tp,
256 unsigned int flag)
257 {
258 tp->event->flags |= flag;
259 }
260
trace_probe_clear_flag(struct trace_probe * tp,unsigned int flag)261 static inline void trace_probe_clear_flag(struct trace_probe *tp,
262 unsigned int flag)
263 {
264 tp->event->flags &= ~flag;
265 }
266
trace_probe_is_enabled(struct trace_probe * tp)267 static inline bool trace_probe_is_enabled(struct trace_probe *tp)
268 {
269 return trace_probe_test_flag(tp, TP_FLAG_TRACE | TP_FLAG_PROFILE);
270 }
271
trace_probe_name(struct trace_probe * tp)272 static inline const char *trace_probe_name(struct trace_probe *tp)
273 {
274 return trace_event_name(&tp->event->call);
275 }
276
trace_probe_group_name(struct trace_probe * tp)277 static inline const char *trace_probe_group_name(struct trace_probe *tp)
278 {
279 return tp->event->call.class->system;
280 }
281
282 static inline struct trace_event_call *
trace_probe_event_call(struct trace_probe * tp)283 trace_probe_event_call(struct trace_probe *tp)
284 {
285 return &tp->event->call;
286 }
287
288 static inline struct trace_probe_event *
trace_probe_event_from_call(struct trace_event_call * event_call)289 trace_probe_event_from_call(struct trace_event_call *event_call)
290 {
291 return container_of(event_call, struct trace_probe_event, call);
292 }
293
294 static inline struct trace_probe *
trace_probe_primary_from_call(struct trace_event_call * call)295 trace_probe_primary_from_call(struct trace_event_call *call)
296 {
297 struct trace_probe_event *tpe = trace_probe_event_from_call(call);
298
299 return list_first_entry(&tpe->probes, struct trace_probe, list);
300 }
301
trace_probe_probe_list(struct trace_probe * tp)302 static inline struct list_head *trace_probe_probe_list(struct trace_probe *tp)
303 {
304 return &tp->event->probes;
305 }
306
trace_probe_has_sibling(struct trace_probe * tp)307 static inline bool trace_probe_has_sibling(struct trace_probe *tp)
308 {
309 struct list_head *list = trace_probe_probe_list(tp);
310
311 return !list_empty(list) && !list_is_singular(list);
312 }
313
trace_probe_unregister_event_call(struct trace_probe * tp)314 static inline int trace_probe_unregister_event_call(struct trace_probe *tp)
315 {
316 /* tp->event is unregistered in trace_remove_event_call() */
317 return trace_remove_event_call(&tp->event->call);
318 }
319
trace_probe_has_single_file(struct trace_probe * tp)320 static inline bool trace_probe_has_single_file(struct trace_probe *tp)
321 {
322 return !!list_is_singular(&tp->event->files);
323 }
324
325 int trace_probe_init(struct trace_probe *tp, const char *event,
326 const char *group, size_t event_data_size);
327 void trace_probe_cleanup(struct trace_probe *tp);
328 int trace_probe_append(struct trace_probe *tp, struct trace_probe *to);
329 void trace_probe_unlink(struct trace_probe *tp);
330 int trace_probe_register_event_call(struct trace_probe *tp);
331 int trace_probe_add_file(struct trace_probe *tp, struct trace_event_file *file);
332 int trace_probe_remove_file(struct trace_probe *tp,
333 struct trace_event_file *file);
334 struct event_file_link *trace_probe_get_file_link(struct trace_probe *tp,
335 struct trace_event_file *file);
336 int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b);
337 bool trace_probe_match_command_args(struct trace_probe *tp,
338 int argc, const char **argv);
339
340 #define trace_probe_for_each_link(pos, tp) \
341 list_for_each_entry(pos, &(tp)->event->files, list)
342 #define trace_probe_for_each_link_rcu(pos, tp) \
343 list_for_each_entry_rcu(pos, &(tp)->event->files, list)
344
345 /* Check the name is good for event/group/fields */
is_good_name(const char * name)346 static inline bool is_good_name(const char *name)
347 {
348 if (!isalpha(*name) && *name != '_')
349 return false;
350 while (*++name != '\0') {
351 if (!isalpha(*name) && !isdigit(*name) && *name != '_')
352 return false;
353 }
354 return true;
355 }
356
357 #define TPARG_FL_RETURN BIT(0)
358 #define TPARG_FL_KERNEL BIT(1)
359 #define TPARG_FL_FENTRY BIT(2)
360 #define TPARG_FL_MASK GENMASK(2, 0)
361
362 extern int traceprobe_parse_probe_arg(struct trace_probe *tp, int i,
363 char *arg, unsigned int flags);
364
365 extern int traceprobe_update_arg(struct probe_arg *arg);
366 extern void traceprobe_free_probe_arg(struct probe_arg *arg);
367
368 extern int traceprobe_split_symbol_offset(char *symbol, long *offset);
369 int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
370 char *buf, int offset);
371
372 extern int traceprobe_set_print_fmt(struct trace_probe *tp, bool is_return);
373
374 #ifdef CONFIG_PERF_EVENTS
375 extern struct trace_event_call *
376 create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
377 bool is_return);
378 extern void destroy_local_trace_kprobe(struct trace_event_call *event_call);
379
380 extern struct trace_event_call *
381 create_local_trace_uprobe(char *name, unsigned long offs,
382 unsigned long ref_ctr_offset, bool is_return);
383 extern void destroy_local_trace_uprobe(struct trace_event_call *event_call);
384 #endif
385 extern int traceprobe_define_arg_fields(struct trace_event_call *event_call,
386 size_t offset, struct trace_probe *tp);
387
388 #undef ERRORS
389 #define ERRORS \
390 C(FILE_NOT_FOUND, "Failed to find the given file"), \
391 C(NO_REGULAR_FILE, "Not a regular file"), \
392 C(BAD_REFCNT, "Invalid reference counter offset"), \
393 C(REFCNT_OPEN_BRACE, "Reference counter brace is not closed"), \
394 C(BAD_REFCNT_SUFFIX, "Reference counter has wrong suffix"), \
395 C(BAD_UPROBE_OFFS, "Invalid uprobe offset"), \
396 C(MAXACT_NO_KPROBE, "Maxactive is not for kprobe"), \
397 C(BAD_MAXACT, "Invalid maxactive number"), \
398 C(MAXACT_TOO_BIG, "Maxactive is too big"), \
399 C(BAD_PROBE_ADDR, "Invalid probed address or symbol"), \
400 C(BAD_RETPROBE, "Retprobe address must be an function entry"), \
401 C(NO_GROUP_NAME, "Group name is not specified"), \
402 C(GROUP_TOO_LONG, "Group name is too long"), \
403 C(BAD_GROUP_NAME, "Group name must follow the same rules as C identifiers"), \
404 C(NO_EVENT_NAME, "Event name is not specified"), \
405 C(EVENT_TOO_LONG, "Event name is too long"), \
406 C(BAD_EVENT_NAME, "Event name must follow the same rules as C identifiers"), \
407 C(RETVAL_ON_PROBE, "$retval is not available on probe"), \
408 C(BAD_STACK_NUM, "Invalid stack number"), \
409 C(BAD_ARG_NUM, "Invalid argument number"), \
410 C(BAD_VAR, "Invalid $-valiable specified"), \
411 C(BAD_REG_NAME, "Invalid register name"), \
412 C(BAD_MEM_ADDR, "Invalid memory address"), \
413 C(BAD_IMM, "Invalid immediate value"), \
414 C(IMMSTR_NO_CLOSE, "String is not closed with '\"'"), \
415 C(FILE_ON_KPROBE, "File offset is not available with kprobe"), \
416 C(BAD_FILE_OFFS, "Invalid file offset value"), \
417 C(SYM_ON_UPROBE, "Symbol is not available with uprobe"), \
418 C(TOO_MANY_OPS, "Dereference is too much nested"), \
419 C(DEREF_NEED_BRACE, "Dereference needs a brace"), \
420 C(BAD_DEREF_OFFS, "Invalid dereference offset"), \
421 C(DEREF_OPEN_BRACE, "Dereference brace is not closed"), \
422 C(COMM_CANT_DEREF, "$comm can not be dereferenced"), \
423 C(BAD_FETCH_ARG, "Invalid fetch argument"), \
424 C(ARRAY_NO_CLOSE, "Array is not closed"), \
425 C(BAD_ARRAY_SUFFIX, "Array has wrong suffix"), \
426 C(BAD_ARRAY_NUM, "Invalid array size"), \
427 C(ARRAY_TOO_BIG, "Array number is too big"), \
428 C(BAD_TYPE, "Unknown type is specified"), \
429 C(BAD_STRING, "String accepts only memory argument"), \
430 C(BAD_BITFIELD, "Invalid bitfield"), \
431 C(ARG_NAME_TOO_LONG, "Argument name is too long"), \
432 C(NO_ARG_NAME, "Argument name is not specified"), \
433 C(BAD_ARG_NAME, "Argument name must follow the same rules as C identifiers"), \
434 C(USED_ARG_NAME, "This argument name is already used"), \
435 C(ARG_TOO_LONG, "Argument expression is too long"), \
436 C(NO_ARG_BODY, "No argument expression"), \
437 C(BAD_INSN_BNDRY, "Probe point is not an instruction boundary"),\
438 C(FAIL_REG_PROBE, "Failed to register probe event"),\
439 C(DIFF_PROBE_TYPE, "Probe type is different from existing probe"),\
440 C(DIFF_ARG_TYPE, "Argument type or name is different from existing probe"),\
441 C(SAME_PROBE, "There is already the exact same probe event"),
442
443 #undef C
444 #define C(a, b) TP_ERR_##a
445
446 /* Define TP_ERR_ */
447 enum { ERRORS };
448
449 /* Error text is defined in trace_probe.c */
450
451 struct trace_probe_log {
452 const char *subsystem;
453 const char **argv;
454 int argc;
455 int index;
456 };
457
458 void trace_probe_log_init(const char *subsystem, int argc, const char **argv);
459 void trace_probe_log_set_index(int index);
460 void trace_probe_log_clear(void);
461 void __trace_probe_log_err(int offset, int err);
462
463 #define trace_probe_log_err(offs, err) \
464 __trace_probe_log_err(offs, TP_ERR_##err)
465