summaryrefslogtreecommitdiff
path: root/kernel/trace/trace_probe.h
blob: 3b3869ae8cfd1542524e7701ce5f44e1e3a912e9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
// SPDX-License-Identifier: GPL-2.0
/*
 * Common header file for probe-based Dynamic events.
 *
 * This code was copied from kernel/trace/trace_kprobe.h written by
 * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
 *
 * Updates to make this generic:
 * Copyright (C) IBM Corporation, 2010-2011
 * Author:     Srikar Dronamraju
 */

#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/smp.h>
#include <linux/tracefs.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/ptrace.h>
#include <linux/perf_event.h>
#include <linux/kprobes.h>
#include <linux/stringify.h>
#include <linux/limits.h>
#include <linux/uaccess.h>
#include <linux/bitops.h>
#include <asm/bitsperlong.h>

#include "trace.h"
#include "trace_output.h"

#define MAX_TRACE_ARGS		128
#define MAX_ARGSTR_LEN		63
#define MAX_ARRAY_LEN		64
#define MAX_ARG_NAME_LEN	32
#define MAX_STRING_SIZE		PATH_MAX

/* Reserved field names */
#define FIELD_STRING_IP		"__probe_ip"
#define FIELD_STRING_RETIP	"__probe_ret_ip"
#define FIELD_STRING_FUNC	"__probe_func"

#undef DEFINE_FIELD
#define DEFINE_FIELD(type, item, name, is_signed)			\
	do {								\
		ret = trace_define_field(event_call, #type, name,	\
					 offsetof(typeof(field), item),	\
					 sizeof(field.item), is_signed, \
					 FILTER_OTHER);			\
		if (ret)						\
			return ret;					\
	} while (0)


/* Flags for trace_probe */
#define TP_FLAG_TRACE		1
#define TP_FLAG_PROFILE		2

/* data_loc: data location, compatible with u32 */
#define make_data_loc(len, offs)	\
	(((u32)(len) << 16) | ((u32)(offs) & 0xffff))
#define get_loc_len(dl)		((u32)(dl) >> 16)
#define get_loc_offs(dl)	((u32)(dl) & 0xffff)

static nokprobe_inline void *get_loc_data(u32 *dl, void *ent)
{
	return (u8 *)ent + get_loc_offs(*dl);
}

static nokprobe_inline u32 update_data_loc(u32 loc, int consumed)
{
	u32 maxlen = get_loc_len(loc);
	u32 offset = get_loc_offs(loc);

	return make_data_loc(maxlen - consumed, offset + consumed);
}

/* Printing function type */
typedef int (*print_type_func_t)(struct trace_seq *, void *, void *);

enum fetch_op {
	FETCH_OP_NOP = 0,
	// Stage 1 (load) ops
	FETCH_OP_REG,		/* Register : .param = offset */
	FETCH_OP_STACK,		/* Stack : .param = index */
	FETCH_OP_STACKP,	/* Stack pointer */
	FETCH_OP_RETVAL,	/* Return value */
	FETCH_OP_IMM,		/* Immediate : .immediate */
	FETCH_OP_COMM,		/* Current comm */
	FETCH_OP_ARG,		/* Function argument : .param */
	FETCH_OP_FOFFS,		/* File offset: .immediate */
	FETCH_OP_DATA,		/* Allocated data: .data */
	// Stage 2 (dereference) op
	FETCH_OP_DEREF,		/* Dereference: .offset */
	FETCH_OP_UDEREF,	/* User-space Dereference: .offset */
	// Stage 3 (store) ops
	FETCH_OP_ST_RAW,	/* Raw: .size */
	FETCH_OP_ST_MEM,	/* Mem: .offset, .size */
	FETCH_OP_ST_UMEM,	/* Mem: .offset, .size */
	FETCH_OP_ST_STRING,	/* String: .offset, .size */
	FETCH_OP_ST_USTRING,	/* User String: .offset, .size */
	// Stage 4 (modify) op
	FETCH_OP_MOD_BF,	/* Bitfield: .basesize, .lshift, .rshift */
	// Stage 5 (loop) op
	FETCH_OP_LP_ARRAY,	/* Array: .param = loop count */
	FETCH_OP_TP_ARG,	/* Trace Point argument */
	FETCH_OP_END,
	FETCH_NOP_SYMBOL,	/* Unresolved Symbol holder */
};

struct fetch_insn {
	enum fetch_op op;
	union {
		unsigned int param;
		struct {
			unsigned int size;
			int offset;
		};
		struct {
			unsigned char basesize;
			unsigned char lshift;
			unsigned char rshift;
		};
		unsigned long immediate;
		void *data;
	};
};

/* fetch + deref*N + store + mod + end <= 16, this allows N=12, enough */
#define FETCH_INSN_MAX	16
#define FETCH_TOKEN_COMM	(-ECOMM)

/* Fetch type information table */
struct fetch_type {
	const char		*name;		/* Name of type */
	size_t			size;		/* Byte size of type */
	int			is_signed;	/* Signed flag */
	print_type_func_t	print;		/* Print functions */
	const char		*fmt;		/* Format string */
	const char		*fmttype;	/* Name in format file */
};

/* For defining macros, define string/string_size types */
typedef u32 string;
typedef u32 string_size;

#define PRINT_TYPE_FUNC_NAME(type)	print_type_##type
#define PRINT_TYPE_FMT_NAME(type)	print_type_format_##type

/* Printing  in basic type function template */
#define DECLARE_BASIC_PRINT_TYPE_FUNC(type)				\
int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, void *data, void *ent);\
extern const char PRINT_TYPE_FMT_NAME(type)[]

DECLARE_BASIC_PRINT_TYPE_FUNC(u8);
DECLARE_BASIC_PRINT_TYPE_FUNC(u16);
DECLARE_BASIC_PRINT_TYPE_FUNC(u32);
DECLARE_BASIC_PRINT_TYPE_FUNC(u64);
DECLARE_BASIC_PRINT_TYPE_FUNC(s8);
DECLARE_BASIC_PRINT_TYPE_FUNC(s16);
DECLARE_BASIC_PRINT_TYPE_FUNC(s32);
DECLARE_BASIC_PRINT_TYPE_FUNC(s64);
DECLARE_BASIC_PRINT_TYPE_FUNC(x8);
DECLARE_BASIC_PRINT_TYPE_FUNC(x16);
DECLARE_BASIC_PRINT_TYPE_FUNC(x32);
DECLARE_BASIC_PRINT_TYPE_FUNC(x64);

DECLARE_BASIC_PRINT_TYPE_FUNC(string);
DECLARE_BASIC_PRINT_TYPE_FUNC(symbol);

/* Default (unsigned long) fetch type */
#define __DEFAULT_FETCH_TYPE(t) x##t
#define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t)
#define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG)
#define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE)

#define __ADDR_FETCH_TYPE(t) u##t
#define _ADDR_FETCH_TYPE(t) __ADDR_FETCH_TYPE(t)
#define ADDR_FETCH_TYPE _ADDR_FETCH_TYPE(BITS_PER_LONG)

#define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype)	\
	{.name = _name,				\
	 .size = _size,					\
	 .is_signed = sign,				\
	 .print = PRINT_TYPE_FUNC_NAME(ptype),		\
	 .fmt = PRINT_TYPE_FMT_NAME(ptype),		\
	 .fmttype = _fmttype,				\
	}
#define _ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype)	\
	__ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, #_fmttype)
#define ASSIGN_FETCH_TYPE(ptype, ftype, sign)			\
	_ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, ptype)

/* If ptype is an alias of atype, use this macro (show atype in format) */
#define ASSIGN_FETCH_TYPE_ALIAS(ptype, atype, ftype, sign)		\
	_ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, atype)

#define ASSIGN_FETCH_TYPE_END {}
#define MAX_ARRAY_LEN	64

#ifdef CONFIG_KPROBE_EVENTS
bool trace_kprobe_on_func_entry(struct trace_event_call *call);
bool trace_kprobe_error_injectable(struct trace_event_call *call);
#else
static inline bool trace_kprobe_on_func_entry(struct trace_event_call *call)
{
	return false;
}

static inline bool trace_kprobe_error_injectable(struct trace_event_call *call)
{
	return false;
}
#endif /* CONFIG_KPROBE_EVENTS */

struct probe_arg {
	struct fetch_insn	*code;
	bool			dynamic;/* Dynamic array (string) is used */
	unsigned int		offset;	/* Offset from argument entry */
	unsigned int		count;	/* Array count */
	const char		*name;	/* Name of this argument */
	const char		*comm;	/* Command of this argument */
	char			*fmt;	/* Format string if needed */
	const struct fetch_type	*type;	/* Type of this argument */
};

struct trace_uprobe_filter {
	rwlock_t		rwlock;
	int			nr_systemwide;
	struct list_head	perf_events;
};

/* Event call and class holder */
struct trace_probe_event {
	unsigned int			flags;	/* For TP_FLAG_* */
	struct trace_event_class	class;
	struct trace_event_call		call;
	struct list_head 		files;
	struct list_head		probes;
	struct trace_uprobe_filter	filter[];
};

struct trace_probe {
	struct list_head		list;
	struct trace_probe_event	*event;
	ssize_t				size;	/* trace entry size */
	unsigned int			nr_args;
	struct probe_arg		args[];
};

struct event_file_link {
	struct trace_event_file		*file;
	struct list_head		list;
};

static inline bool trace_probe_test_flag(struct trace_probe *tp,
					 unsigned int flag)
{
	return !!(tp->event->flags & flag);
}

static inline void trace_probe_set_flag(struct trace_probe *tp,
					unsigned int flag)
{
	tp->event->flags |= flag;
}

static inline void trace_probe_clear_flag(struct trace_probe *tp,
					  unsigned int flag)
{
	tp->event->flags &= ~flag;
}

static inline bool trace_probe_is_enabled(struct trace_probe *tp)
{
	return trace_probe_test_flag(tp, TP_FLAG_TRACE | TP_FLAG_PROFILE);
}

static inline const char *trace_probe_name(struct trace_probe *tp)
{
	return trace_event_name(&tp->event->call);
}

static inline const char *trace_probe_group_name(struct trace_probe *tp)
{
	return tp->event->call.class->system;
}

static inline struct trace_event_call *
	trace_probe_event_call(struct trace_probe *tp)
{
	return &tp->event->call;
}

static inline struct trace_probe_event *
trace_probe_event_from_call(struct trace_event_call *event_call)
{
	return container_of(event_call, struct trace_probe_event, call);
}

static inline struct trace_probe *
trace_probe_primary_from_call(struct trace_event_call *call)
{
	struct trace_probe_event *tpe = trace_probe_event_from_call(call);

	return list_first_entry(&tpe->probes, struct trace_probe, list);
}

static inline struct list_head *trace_probe_probe_list(struct trace_probe *tp)
{
	return &tp->event->probes;
}

static inline bool trace_probe_has_sibling(struct trace_probe *tp)
{
	struct list_head *list = trace_probe_probe_list(tp);

	return !list_empty(list) && !list_is_singular(list);
}

static inline int trace_probe_unregister_event_call(struct trace_probe *tp)
{
	/* tp->event is unregistered in trace_remove_event_call() */
	return trace_remove_event_call(&tp->event->call);
}

static inline bool trace_probe_has_single_file(struct trace_probe *tp)
{
	return !!list_is_singular(&tp->event->files);
}

int trace_probe_init(struct trace_probe *tp, const char *event,
		     const char *group, bool alloc_filter);
void trace_probe_cleanup(struct trace_probe *tp);
int trace_probe_append(struct trace_probe *tp, struct trace_probe *to);
void trace_probe_unlink(struct trace_probe *tp);
int trace_probe_register_event_call(struct trace_probe *tp);
int trace_probe_add_file(struct trace_probe *tp, struct trace_event_file *file);
int trace_probe_remove_file(struct trace_probe *tp,
			    struct trace_event_file *file);
struct event_file_link *trace_probe_get_file_link(struct trace_probe *tp,
						struct trace_event_file *file);
int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b);
bool trace_probe_match_command_args(struct trace_probe *tp,
				    int argc, const char **argv);
int trace_probe_create(const char *raw_command, int (*createfn)(int, const char **));

#define trace_probe_for_each_link(pos, tp)	\
	list_for_each_entry(pos, &(tp)->event->files, list)
#define trace_probe_for_each_link_rcu(pos, tp)	\
	list_for_each_entry_rcu(pos, &(tp)->event->files, list)

#define TPARG_FL_RETURN BIT(0)
#define TPARG_FL_KERNEL BIT(1)
#define TPARG_FL_FENTRY BIT(2)
#define TPARG_FL_TPOINT BIT(3)
#define TPARG_FL_MASK	GENMASK(3, 0)

extern int traceprobe_parse_probe_arg(struct trace_probe *tp, int i,
				const char *argv, unsigned int flags);

extern int traceprobe_update_arg(struct probe_arg *arg);
extern void traceprobe_free_probe_arg(struct probe_arg *arg);

extern int traceprobe_split_symbol_offset(char *symbol, long *offset);
int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
				char *buf, int offset);

enum probe_print_type {
	PROBE_PRINT_NORMAL,
	PROBE_PRINT_RETURN,
	PROBE_PRINT_EVENT,
};

extern int traceprobe_set_print_fmt(struct trace_probe *tp, enum probe_print_type ptype);

#ifdef CONFIG_PERF_EVENTS
extern struct trace_event_call *
create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
			  bool is_return);
extern void destroy_local_trace_kprobe(struct trace_event_call *event_call);

extern struct trace_event_call *
create_local_trace_uprobe(char *name, unsigned long offs,
			  unsigned long ref_ctr_offset, bool is_return);
extern void destroy_local_trace_uprobe(struct trace_event_call *event_call);
#endif
extern int traceprobe_define_arg_fields(struct trace_event_call *event_call,
					size_t offset, struct trace_probe *tp);

#undef ERRORS
#define ERRORS	\
	C(FILE_NOT_FOUND,	"Failed to find the given file"),	\
	C(NO_REGULAR_FILE,	"Not a regular file"),			\
	C(BAD_REFCNT,		"Invalid reference counter offset"),	\
	C(REFCNT_OPEN_BRACE,	"Reference counter brace is not closed"), \
	C(BAD_REFCNT_SUFFIX,	"Reference counter has wrong suffix"),	\
	C(BAD_UPROBE_OFFS,	"Invalid uprobe offset"),		\
	C(MAXACT_NO_KPROBE,	"Maxactive is not for kprobe"),		\
	C(BAD_MAXACT,		"Invalid maxactive number"),		\
	C(MAXACT_TOO_BIG,	"Maxactive is too big"),		\
	C(BAD_PROBE_ADDR,	"Invalid probed address or symbol"),	\
	C(BAD_RETPROBE,		"Retprobe address must be an function entry"), \
	C(BAD_ADDR_SUFFIX,	"Invalid probed address suffix"), \
	C(NO_GROUP_NAME,	"Group name is not specified"),		\
	C(GROUP_TOO_LONG,	"Group name is too long"),		\
	C(BAD_GROUP_NAME,	"Group name must follow the same rules as C identifiers"), \
	C(NO_EVENT_NAME,	"Event name is not specified"),		\
	C(EVENT_TOO_LONG,	"Event name is too long"),		\
	C(BAD_EVENT_NAME,	"Event name must follow the same rules as C identifiers"), \
	C(EVENT_EXIST,		"Given group/event name is already used by another event"), \
	C(RETVAL_ON_PROBE,	"$retval is not available on probe"),	\
	C(BAD_STACK_NUM,	"Invalid stack number"),		\
	C(BAD_ARG_NUM,		"Invalid argument number"),		\
	C(BAD_VAR,		"Invalid $-valiable specified"),	\
	C(BAD_REG_NAME,		"Invalid register name"),		\
	C(BAD_MEM_ADDR,		"Invalid memory address"),		\
	C(BAD_IMM,		"Invalid immediate value"),		\
	C(IMMSTR_NO_CLOSE,	"String is not closed with '\"'"),	\
	C(FILE_ON_KPROBE,	"File offset is not available with kprobe"), \
	C(BAD_FILE_OFFS,	"Invalid file offset value"),		\
	C(SYM_ON_UPROBE,	"Symbol is not available with uprobe"),	\
	C(TOO_MANY_OPS,		"Dereference is too much nested"), 	\
	C(DEREF_NEED_BRACE,	"Dereference needs a brace"),		\
	C(BAD_DEREF_OFFS,	"Invalid dereference offset"),		\
	C(DEREF_OPEN_BRACE,	"Dereference brace is not closed"),	\
	C(COMM_CANT_DEREF,	"$comm can not be dereferenced"),	\
	C(BAD_FETCH_ARG,	"Invalid fetch argument"),		\
	C(ARRAY_NO_CLOSE,	"Array is not closed"),			\
	C(BAD_ARRAY_SUFFIX,	"Array has wrong suffix"),		\
	C(BAD_ARRAY_NUM,	"Invalid array size"),			\
	C(ARRAY_TOO_BIG,	"Array number is too big"),		\
	C(BAD_TYPE,		"Unknown type is specified"),		\
	C(BAD_STRING,		"String accepts only memory argument"),	\
	C(BAD_BITFIELD,		"Invalid bitfield"),			\
	C(ARG_NAME_TOO_LONG,	"Argument name is too long"),		\
	C(NO_ARG_NAME,		"Argument name is not specified"),	\
	C(BAD_ARG_NAME,		"Argument name must follow the same rules as C identifiers"), \
	C(USED_ARG_NAME,	"This argument name is already used"),	\
	C(ARG_TOO_LONG,		"Argument expression is too long"),	\
	C(NO_ARG_BODY,		"No argument expression"),		\
	C(BAD_INSN_BNDRY,	"Probe point is not an instruction boundary"),\
	C(FAIL_REG_PROBE,	"Failed to register probe event"),\
	C(DIFF_PROBE_TYPE,	"Probe type is different from existing probe"),\
	C(DIFF_ARG_TYPE,	"Argument type or name is different from existing probe"),\
	C(SAME_PROBE,		"There is already the exact same probe event"),\
	C(NO_EVENT_INFO,	"This requires both group and event name to attach"),\
	C(BAD_ATTACH_EVENT,	"Attached event does not exist"),\
	C(BAD_ATTACH_ARG,	"Attached event does not have this field"),

#undef C
#define C(a, b)		TP_ERR_##a

/* Define TP_ERR_ */
enum { ERRORS };

/* Error text is defined in trace_probe.c */

struct trace_probe_log {
	const char	*subsystem;
	const char	**argv;
	int		argc;
	int		index;
};

void trace_probe_log_init(const char *subsystem, int argc, const char **argv);
void trace_probe_log_set_index(int index);
void trace_probe_log_clear(void);
void __trace_probe_log_err(int offset, int err);

#define trace_probe_log_err(offs, err)	\
	__trace_probe_log_err(offs, TP_ERR_##err)