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#define TP_FLAG_REGISTERED 4
59
60/* data_loc: data location, compatible with u32 */
61#define make_data_loc(len, offs) \
62 (((u32)(len) << 16) | ((u32)(offs) & 0xffff))
63#define get_loc_len(dl) ((u32)(dl) >> 16)
64#define get_loc_offs(dl) ((u32)(dl) & 0xffff)
65
66static nokprobe_inline void *get_loc_data(u32 *dl, void *ent)
67{
68 return (u8 *)ent + get_loc_offs(*dl);
69}
70
71static nokprobe_inline u32 update_data_loc(u32 loc, int consumed)
72{
73 u32 maxlen = get_loc_len(loc);
74 u32 offset = get_loc_offs(loc);
75
76 return make_data_loc(maxlen - consumed, offset + consumed);
77}
78
79/* Printing function type */
80typedef int (*print_type_func_t)(struct trace_seq *, void *, void *);
81
82enum fetch_op {
83 FETCH_OP_NOP = 0,
84 // Stage 1 (load) ops
85 FETCH_OP_REG, /* Register : .param = offset */
86 FETCH_OP_STACK, /* Stack : .param = index */
87 FETCH_OP_STACKP, /* Stack pointer */
88 FETCH_OP_RETVAL, /* Return value */
89 FETCH_OP_IMM, /* Immediate : .immediate */
90 FETCH_OP_COMM, /* Current comm */
91 FETCH_OP_ARG, /* Function argument : .param */
92 FETCH_OP_FOFFS, /* File offset: .immediate */
93 // Stage 2 (dereference) op
94 FETCH_OP_DEREF, /* Dereference: .offset */
95 // Stage 3 (store) ops
96 FETCH_OP_ST_RAW, /* Raw: .size */
97 FETCH_OP_ST_MEM, /* Mem: .offset, .size */
98 FETCH_OP_ST_STRING, /* String: .offset, .size */
99 // Stage 4 (modify) op
100 FETCH_OP_MOD_BF, /* Bitfield: .basesize, .lshift, .rshift */
101 // Stage 5 (loop) op
102 FETCH_OP_LP_ARRAY, /* Array: .param = loop count */
103 FETCH_OP_END,
104 FETCH_NOP_SYMBOL, /* Unresolved Symbol holder */
105};
106
107struct fetch_insn {
108 enum fetch_op op;
109 union {
110 unsigned int param;
111 struct {
112 unsigned int size;
113 int offset;
114 };
115 struct {
116 unsigned char basesize;
117 unsigned char lshift;
118 unsigned char rshift;
119 };
120 unsigned long immediate;
121 void *data;
122 };
123};
124
125/* fetch + deref*N + store + mod + end <= 16, this allows N=12, enough */
126#define FETCH_INSN_MAX 16
127
128/* Fetch type information table */
129struct fetch_type {
130 const char *name; /* Name of type */
131 size_t size; /* Byte size of type */
132 int is_signed; /* Signed flag */
133 print_type_func_t print; /* Print functions */
134 const char *fmt; /* Fromat string */
135 const char *fmttype; /* Name in format file */
136};
137
138/* For defining macros, define string/string_size types */
139typedef u32 string;
140typedef u32 string_size;
141
142#define PRINT_TYPE_FUNC_NAME(type) print_type_##type
143#define PRINT_TYPE_FMT_NAME(type) print_type_format_##type
144
145/* Printing in basic type function template */
146#define DECLARE_BASIC_PRINT_TYPE_FUNC(type) \
147int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, void *data, void *ent);\
148extern const char PRINT_TYPE_FMT_NAME(type)[]
149
150DECLARE_BASIC_PRINT_TYPE_FUNC(u8);
151DECLARE_BASIC_PRINT_TYPE_FUNC(u16);
152DECLARE_BASIC_PRINT_TYPE_FUNC(u32);
153DECLARE_BASIC_PRINT_TYPE_FUNC(u64);
154DECLARE_BASIC_PRINT_TYPE_FUNC(s8);
155DECLARE_BASIC_PRINT_TYPE_FUNC(s16);
156DECLARE_BASIC_PRINT_TYPE_FUNC(s32);
157DECLARE_BASIC_PRINT_TYPE_FUNC(s64);
158DECLARE_BASIC_PRINT_TYPE_FUNC(x8);
159DECLARE_BASIC_PRINT_TYPE_FUNC(x16);
160DECLARE_BASIC_PRINT_TYPE_FUNC(x32);
161DECLARE_BASIC_PRINT_TYPE_FUNC(x64);
162
163DECLARE_BASIC_PRINT_TYPE_FUNC(string);
164DECLARE_BASIC_PRINT_TYPE_FUNC(symbol);
165
166/* Default (unsigned long) fetch type */
167#define __DEFAULT_FETCH_TYPE(t) x##t
168#define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t)
169#define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG)
170#define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE)
171
172#define __ADDR_FETCH_TYPE(t) u##t
173#define _ADDR_FETCH_TYPE(t) __ADDR_FETCH_TYPE(t)
174#define ADDR_FETCH_TYPE _ADDR_FETCH_TYPE(BITS_PER_LONG)
175
176#define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \
177 {.name = _name, \
178 .size = _size, \
179 .is_signed = sign, \
180 .print = PRINT_TYPE_FUNC_NAME(ptype), \
181 .fmt = PRINT_TYPE_FMT_NAME(ptype), \
182 .fmttype = _fmttype, \
183 }
184#define _ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \
185 __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, #_fmttype)
186#define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \
187 _ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, ptype)
188
189/* If ptype is an alias of atype, use this macro (show atype in format) */
190#define ASSIGN_FETCH_TYPE_ALIAS(ptype, atype, ftype, sign) \
191 _ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, atype)
192
193#define ASSIGN_FETCH_TYPE_END {}
194#define MAX_ARRAY_LEN 64
195
196#ifdef CONFIG_KPROBE_EVENTS
197bool trace_kprobe_on_func_entry(struct trace_event_call *call);
198bool trace_kprobe_error_injectable(struct trace_event_call *call);
199#else
200static inline bool trace_kprobe_on_func_entry(struct trace_event_call *call)
201{
202 return false;
203}
204
205static inline bool trace_kprobe_error_injectable(struct trace_event_call *call)
206{
207 return false;
208}
209#endif /* CONFIG_KPROBE_EVENTS */
210
211struct probe_arg {
212 struct fetch_insn *code;
213 bool dynamic;/* Dynamic array (string) is used */
214 unsigned int offset; /* Offset from argument entry */
215 unsigned int count; /* Array count */
216 const char *name; /* Name of this argument */
217 const char *comm; /* Command of this argument */
218 char *fmt; /* Format string if needed */
219 const struct fetch_type *type; /* Type of this argument */
220};
221
222struct trace_probe {
223 unsigned int flags; /* For TP_FLAG_* */
224 struct trace_event_class class;
225 struct trace_event_call call;
226 struct list_head files;
227 ssize_t size; /* trace entry size */
228 unsigned int nr_args;
229 struct probe_arg args[];
230};
231
232struct event_file_link {
233 struct trace_event_file *file;
234 struct list_head list;
235};
236
237static inline bool trace_probe_is_enabled(struct trace_probe *tp)
238{
239 return !!(tp->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE));
240}
241
242static inline bool trace_probe_is_registered(struct trace_probe *tp)
243{
244 return !!(tp->flags & TP_FLAG_REGISTERED);
245}
246
247/* Check the name is good for event/group/fields */
248static inline bool is_good_name(const char *name)
249{
250 if (!isalpha(*name) && *name != '_')
251 return false;
252 while (*++name != '\0') {
253 if (!isalpha(*name) && !isdigit(*name) && *name != '_')
254 return false;
255 }
256 return true;
257}
258
259static inline struct event_file_link *
260find_event_file_link(struct trace_probe *tp, struct trace_event_file *file)
261{
262 struct event_file_link *link;
263
264 list_for_each_entry(link, &tp->files, list)
265 if (link->file == file)
266 return link;
267
268 return NULL;
269}
270
271#define TPARG_FL_RETURN BIT(0)
272#define TPARG_FL_KERNEL BIT(1)
273#define TPARG_FL_FENTRY BIT(2)
274#define TPARG_FL_MASK GENMASK(2, 0)
275
276extern int traceprobe_parse_probe_arg(struct trace_probe *tp, int i,
277 char *arg, unsigned int flags);
278
279extern int traceprobe_update_arg(struct probe_arg *arg);
280extern void traceprobe_free_probe_arg(struct probe_arg *arg);
281
282extern int traceprobe_split_symbol_offset(char *symbol, long *offset);
283extern int traceprobe_parse_event_name(const char **pevent,
284 const char **pgroup, char *buf);
285
286extern int traceprobe_set_print_fmt(struct trace_probe *tp, bool is_return);
287
288#ifdef CONFIG_PERF_EVENTS
289extern struct trace_event_call *
290create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
291 bool is_return);
292extern void destroy_local_trace_kprobe(struct trace_event_call *event_call);
293
294extern struct trace_event_call *
295create_local_trace_uprobe(char *name, unsigned long offs,
296 unsigned long ref_ctr_offset, bool is_return);
297extern void destroy_local_trace_uprobe(struct trace_event_call *event_call);
298#endif
299extern int traceprobe_define_arg_fields(struct trace_event_call *event_call,
300 size_t offset, struct trace_probe *tp);
301