summaryrefslogtreecommitdiffstats
path: root/kernel/trace/trace_probe.h
blob: b6bdd82fa4856f13379e5b1e2f73bf8e7459697f (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
// 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/ctype.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 <asm/bitsperlong.h>

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

#define MAX_TRACE_ARGS		128
#define MAX_ARGSTR_LEN		63
#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
#define TP_FLAG_REGISTERED	4

/* 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);
}

/* 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_FOFFS,		/* File offset: .immediate */
	// Stage 2 (dereference) op
	FETCH_OP_DEREF,		/* Dereference: .offset */
	// Stage 3 (store) ops
	FETCH_OP_ST_RAW,	/* Raw: .size */
	FETCH_OP_ST_MEM,	/* Mem: .offset, .size */
	FETCH_OP_ST_STRING,	/* String: .offset, .size */
	// Stage 4 (modify) op
	FETCH_OP_MOD_BF,	/* Bitfield: .basesize, .lshift, .rshift */
	FETCH_OP_END,
};

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;
	};
};

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

/* 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;		/* Fromat 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);

/* 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 __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(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 {}

#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 */
	const char		*name;	/* Name of this argument */
	const char		*comm;	/* Command of this argument */
	const struct fetch_type	*type;	/* Type of this argument */
};

struct trace_probe {
	unsigned int			flags;	/* For TP_FLAG_* */
	struct trace_event_class	class;
	struct trace_event_call		call;
	struct list_head 		files;
	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_is_enabled(struct trace_probe *tp)
{
	return !!(tp->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE));
}

static inline bool trace_probe_is_registered(struct trace_probe *tp)
{
	return !!(tp->flags & TP_FLAG_REGISTERED);
}

/* Check the name is good for event/group/fields */
static inline bool is_good_name(const char *name)
{
	if (!isalpha(*name) && *name != '_')
		return false;
	while (*++name != '\0') {
		if (!isalpha(*name) && !isdigit(*name) && *name != '_')
			return false;
	}
	return true;
}

static inline struct event_file_link *
find_event_file_link(struct trace_probe *tp, struct trace_event_file *file)
{
	struct event_file_link *link;

	list_for_each_entry(link, &tp->files, list)
		if (link->file == file)
			return link;

	return NULL;
}

extern int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
		   struct probe_arg *parg, bool is_return, bool is_kprobe);

extern int traceprobe_conflict_field_name(const char *name,
			       struct probe_arg *args, int narg);

extern void 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);

extern int set_print_fmt(struct trace_probe *tp, bool is_return);

#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);
OpenPOWER on IntegriCloud