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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/ptrace.h>
20#include <linux/perf_event.h>
21#include <linux/kprobes.h>
22#include <linux/stringify.h>
23#include <linux/limits.h>
24#include <linux/uaccess.h>
25#include <linux/bitops.h>
26#include <asm/bitsperlong.h>
27
28#include "trace.h"
29#include "trace_output.h"
30
31#define MAX_TRACE_ARGS 128
32#define MAX_ARGSTR_LEN 63
33#define MAX_ARRAY_LEN 64
34#define MAX_ARG_NAME_LEN 32
35#define MAX_STRING_SIZE PATH_MAX
36
37/* Reserved field names */
38#define FIELD_STRING_IP "__probe_ip"
39#define FIELD_STRING_RETIP "__probe_ret_ip"
40#define FIELD_STRING_FUNC "__probe_func"
41
42#undef DEFINE_FIELD
43#define DEFINE_FIELD(type, item, name, is_signed) \
44 do { \
45 ret = trace_define_field(event_call, #type, name, \
46 offsetof(typeof(field), item), \
47 sizeof(field.item), is_signed, \
48 FILTER_OTHER); \
49 if (ret) \
50 return ret; \
51 } while (0)
52
53
54/* Flags for trace_probe */
55#define TP_FLAG_TRACE 1
56#define TP_FLAG_PROFILE 2
57
58/* data_loc: data location, compatible with u32 */
59#define make_data_loc(len, offs) \
60 (((u32)(len) << 16) | ((u32)(offs) & 0xffff))
61#define get_loc_len(dl) ((u32)(dl) >> 16)
62#define get_loc_offs(dl) ((u32)(dl) & 0xffff)
63
64static nokprobe_inline void *get_loc_data(u32 *dl, void *ent)
65{
66 return (u8 *)ent + get_loc_offs(*dl);
67}
68
69static nokprobe_inline u32 update_data_loc(u32 loc, int consumed)
70{
71 u32 maxlen = get_loc_len(loc);
72 u32 offset = get_loc_offs(loc);
73
74 return make_data_loc(maxlen - consumed, offset + consumed);
75}
76
77/* Printing function type */
78typedef int (*print_type_func_t)(struct trace_seq *, void *, void *);
79
80enum fetch_op {
81 FETCH_OP_NOP = 0,
82 // Stage 1 (load) ops
83 FETCH_OP_REG, /* Register : .param = offset */
84 FETCH_OP_STACK, /* Stack : .param = index */
85 FETCH_OP_STACKP, /* Stack pointer */
86 FETCH_OP_RETVAL, /* Return value */
87 FETCH_OP_IMM, /* Immediate : .immediate */
88 FETCH_OP_COMM, /* Current comm */
89 FETCH_OP_ARG, /* Function argument : .param */
90 FETCH_OP_FOFFS, /* File offset: .immediate */
91 FETCH_OP_DATA, /* Allocated data: .data */
92 // Stage 2 (dereference) op
93 FETCH_OP_DEREF, /* Dereference: .offset */
94 FETCH_OP_UDEREF, /* User-space 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_UMEM, /* Mem: .offset, .size */
99 FETCH_OP_ST_STRING, /* String: .offset, .size */
100 FETCH_OP_ST_USTRING, /* User String: .offset, .size */
101 FETCH_OP_ST_SYMSTR, /* Kernel Symbol 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_TP_ARG, /* Trace Point argument */
107 FETCH_OP_END,
108 FETCH_NOP_SYMBOL, /* Unresolved Symbol holder */
109};
110
111struct fetch_insn {
112 enum fetch_op op;
113 union {
114 unsigned int param;
115 struct {
116 unsigned int size;
117 int offset;
118 };
119 struct {
120 unsigned char basesize;
121 unsigned char lshift;
122 unsigned char rshift;
123 };
124 unsigned long immediate;
125 void *data;
126 };
127};
128
129/* fetch + deref*N + store + mod + end <= 16, this allows N=12, enough */
130#define FETCH_INSN_MAX 16
131#define FETCH_TOKEN_COMM (-ECOMM)
132
133/* Fetch type information table */
134struct fetch_type {
135 const char *name; /* Name of type */
136 size_t size; /* Byte size of type */
137 bool is_signed; /* Signed flag */
138 bool is_string; /* String flag */
139 print_type_func_t print; /* Print functions */
140 const char *fmt; /* Format string */
141 const char *fmttype; /* Name in format file */
142};
143
144/* For defining macros, define string/string_size types */
145typedef u32 string;
146typedef u32 string_size;
147
148#define PRINT_TYPE_FUNC_NAME(type) print_type_##type
149#define PRINT_TYPE_FMT_NAME(type) print_type_format_##type
150
151/* Printing in basic type function template */
152#define DECLARE_BASIC_PRINT_TYPE_FUNC(type) \
153int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, void *data, void *ent);\
154extern const char PRINT_TYPE_FMT_NAME(type)[]
155
156DECLARE_BASIC_PRINT_TYPE_FUNC(u8);
157DECLARE_BASIC_PRINT_TYPE_FUNC(u16);
158DECLARE_BASIC_PRINT_TYPE_FUNC(u32);
159DECLARE_BASIC_PRINT_TYPE_FUNC(u64);
160DECLARE_BASIC_PRINT_TYPE_FUNC(s8);
161DECLARE_BASIC_PRINT_TYPE_FUNC(s16);
162DECLARE_BASIC_PRINT_TYPE_FUNC(s32);
163DECLARE_BASIC_PRINT_TYPE_FUNC(s64);
164DECLARE_BASIC_PRINT_TYPE_FUNC(x8);
165DECLARE_BASIC_PRINT_TYPE_FUNC(x16);
166DECLARE_BASIC_PRINT_TYPE_FUNC(x32);
167DECLARE_BASIC_PRINT_TYPE_FUNC(x64);
168
169DECLARE_BASIC_PRINT_TYPE_FUNC(string);
170DECLARE_BASIC_PRINT_TYPE_FUNC(symbol);
171
172/* Default (unsigned long) fetch type */
173#define __DEFAULT_FETCH_TYPE(t) x##t
174#define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t)
175#define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG)
176#define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE)
177
178#define __ADDR_FETCH_TYPE(t) u##t
179#define _ADDR_FETCH_TYPE(t) __ADDR_FETCH_TYPE(t)
180#define ADDR_FETCH_TYPE _ADDR_FETCH_TYPE(BITS_PER_LONG)
181
182#define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, str, _fmttype) \
183 {.name = _name, \
184 .size = _size, \
185 .is_signed = (bool)sign, \
186 .is_string = (bool)str, \
187 .print = PRINT_TYPE_FUNC_NAME(ptype), \
188 .fmt = PRINT_TYPE_FMT_NAME(ptype), \
189 .fmttype = _fmttype, \
190 }
191
192/* Non string types can use these macros */
193#define _ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \
194 __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, 0, #_fmttype)
195#define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \
196 _ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, ptype)
197
198/* If ptype is an alias of atype, use this macro (show atype in format) */
199#define ASSIGN_FETCH_TYPE_ALIAS(ptype, atype, ftype, sign) \
200 _ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, atype)
201
202#define ASSIGN_FETCH_TYPE_END {}
203#define MAX_ARRAY_LEN 64
204
205#ifdef CONFIG_KPROBE_EVENTS
206bool trace_kprobe_on_func_entry(struct trace_event_call *call);
207bool trace_kprobe_error_injectable(struct trace_event_call *call);
208#else
209static inline bool trace_kprobe_on_func_entry(struct trace_event_call *call)
210{
211 return false;
212}
213
214static inline bool trace_kprobe_error_injectable(struct trace_event_call *call)
215{
216 return false;
217}
218#endif /* CONFIG_KPROBE_EVENTS */
219
220struct probe_arg {
221 struct fetch_insn *code;
222 bool dynamic;/* Dynamic array (string) is used */
223 unsigned int offset; /* Offset from argument entry */
224 unsigned int count; /* Array count */
225 const char *name; /* Name of this argument */
226 const char *comm; /* Command of this argument */
227 char *fmt; /* Format string if needed */
228 const struct fetch_type *type; /* Type of this argument */
229};
230
231struct trace_uprobe_filter {
232 rwlock_t rwlock;
233 int nr_systemwide;
234 struct list_head perf_events;
235};
236
237/* Event call and class holder */
238struct trace_probe_event {
239 unsigned int flags; /* For TP_FLAG_* */
240 struct trace_event_class class;
241 struct trace_event_call call;
242 struct list_head files;
243 struct list_head probes;
244 struct trace_uprobe_filter filter[];
245};
246
247struct trace_probe {
248 struct list_head list;
249 struct trace_probe_event *event;
250 ssize_t size; /* trace entry size */
251 unsigned int nr_args;
252 struct probe_arg args[];
253};
254
255struct event_file_link {
256 struct trace_event_file *file;
257 struct list_head list;
258};
259
260static inline bool trace_probe_test_flag(struct trace_probe *tp,
261 unsigned int flag)
262{
263 return !!(tp->event->flags & flag);
264}
265
266static inline void trace_probe_set_flag(struct trace_probe *tp,
267 unsigned int flag)
268{
269 tp->event->flags |= flag;
270}
271
272static inline void trace_probe_clear_flag(struct trace_probe *tp,
273 unsigned int flag)
274{
275 tp->event->flags &= ~flag;
276}
277
278static inline bool trace_probe_is_enabled(struct trace_probe *tp)
279{
280 return trace_probe_test_flag(tp, TP_FLAG_TRACE | TP_FLAG_PROFILE);
281}
282
283static inline const char *trace_probe_name(struct trace_probe *tp)
284{
285 return trace_event_name(&tp->event->call);
286}
287
288static inline const char *trace_probe_group_name(struct trace_probe *tp)
289{
290 return tp->event->call.class->system;
291}
292
293static inline struct trace_event_call *
294 trace_probe_event_call(struct trace_probe *tp)
295{
296 return &tp->event->call;
297}
298
299static inline struct trace_probe_event *
300trace_probe_event_from_call(struct trace_event_call *event_call)
301{
302 return container_of(event_call, struct trace_probe_event, call);
303}
304
305static inline struct trace_probe *
306trace_probe_primary_from_call(struct trace_event_call *call)
307{
308 struct trace_probe_event *tpe = trace_probe_event_from_call(call);
309
310 return list_first_entry(&tpe->probes, struct trace_probe, list);
311}
312
313static inline struct list_head *trace_probe_probe_list(struct trace_probe *tp)
314{
315 return &tp->event->probes;
316}
317
318static inline bool trace_probe_has_sibling(struct trace_probe *tp)
319{
320 struct list_head *list = trace_probe_probe_list(tp);
321
322 return !list_empty(list) && !list_is_singular(list);
323}
324
325static inline int trace_probe_unregister_event_call(struct trace_probe *tp)
326{
327 /* tp->event is unregistered in trace_remove_event_call() */
328 return trace_remove_event_call(&tp->event->call);
329}
330
331static inline bool trace_probe_has_single_file(struct trace_probe *tp)
332{
333 return !!list_is_singular(&tp->event->files);
334}
335
336int trace_probe_init(struct trace_probe *tp, const char *event,
337 const char *group, bool alloc_filter);
338void trace_probe_cleanup(struct trace_probe *tp);
339int trace_probe_append(struct trace_probe *tp, struct trace_probe *to);
340void trace_probe_unlink(struct trace_probe *tp);
341int trace_probe_register_event_call(struct trace_probe *tp);
342int trace_probe_add_file(struct trace_probe *tp, struct trace_event_file *file);
343int trace_probe_remove_file(struct trace_probe *tp,
344 struct trace_event_file *file);
345struct event_file_link *trace_probe_get_file_link(struct trace_probe *tp,
346 struct trace_event_file *file);
347int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b);
348bool trace_probe_match_command_args(struct trace_probe *tp,
349 int argc, const char **argv);
350int trace_probe_create(const char *raw_command, int (*createfn)(int, const char **));
351
352#define trace_probe_for_each_link(pos, tp) \
353 list_for_each_entry(pos, &(tp)->event->files, list)
354#define trace_probe_for_each_link_rcu(pos, tp) \
355 list_for_each_entry_rcu(pos, &(tp)->event->files, list)
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_TPOINT BIT(3)
361#define TPARG_FL_USER BIT(4)
362#define TPARG_FL_MASK GENMASK(4, 0)
363
364extern int traceprobe_parse_probe_arg(struct trace_probe *tp, int i,
365 const char *argv, unsigned int flags);
366
367extern int traceprobe_update_arg(struct probe_arg *arg);
368extern void traceprobe_free_probe_arg(struct probe_arg *arg);
369
370extern int traceprobe_split_symbol_offset(char *symbol, long *offset);
371int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
372 char *buf, int offset);
373
374enum probe_print_type {
375 PROBE_PRINT_NORMAL,
376 PROBE_PRINT_RETURN,
377 PROBE_PRINT_EVENT,
378};
379
380extern int traceprobe_set_print_fmt(struct trace_probe *tp, enum probe_print_type ptype);
381
382#ifdef CONFIG_PERF_EVENTS
383extern struct trace_event_call *
384create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
385 bool is_return);
386extern void destroy_local_trace_kprobe(struct trace_event_call *event_call);
387
388extern struct trace_event_call *
389create_local_trace_uprobe(char *name, unsigned long offs,
390 unsigned long ref_ctr_offset, bool is_return);
391extern void destroy_local_trace_uprobe(struct trace_event_call *event_call);
392#endif
393extern int traceprobe_define_arg_fields(struct trace_event_call *event_call,
394 size_t offset, struct trace_probe *tp);
395
396#undef ERRORS
397#define ERRORS \
398 C(FILE_NOT_FOUND, "Failed to find the given file"), \
399 C(NO_REGULAR_FILE, "Not a regular file"), \
400 C(BAD_REFCNT, "Invalid reference counter offset"), \
401 C(REFCNT_OPEN_BRACE, "Reference counter brace is not closed"), \
402 C(BAD_REFCNT_SUFFIX, "Reference counter has wrong suffix"), \
403 C(BAD_UPROBE_OFFS, "Invalid uprobe offset"), \
404 C(MAXACT_NO_KPROBE, "Maxactive is not for kprobe"), \
405 C(BAD_MAXACT, "Invalid maxactive number"), \
406 C(MAXACT_TOO_BIG, "Maxactive is too big"), \
407 C(BAD_PROBE_ADDR, "Invalid probed address or symbol"), \
408 C(BAD_RETPROBE, "Retprobe address must be an function entry"), \
409 C(BAD_ADDR_SUFFIX, "Invalid probed address suffix"), \
410 C(NO_GROUP_NAME, "Group name is not specified"), \
411 C(GROUP_TOO_LONG, "Group name is too long"), \
412 C(BAD_GROUP_NAME, "Group name must follow the same rules as C identifiers"), \
413 C(NO_EVENT_NAME, "Event name is not specified"), \
414 C(EVENT_TOO_LONG, "Event name is too long"), \
415 C(BAD_EVENT_NAME, "Event name must follow the same rules as C identifiers"), \
416 C(EVENT_EXIST, "Given group/event name is already used by another event"), \
417 C(RETVAL_ON_PROBE, "$retval is not available on probe"), \
418 C(BAD_STACK_NUM, "Invalid stack number"), \
419 C(BAD_ARG_NUM, "Invalid argument number"), \
420 C(BAD_VAR, "Invalid $-valiable specified"), \
421 C(BAD_REG_NAME, "Invalid register name"), \
422 C(BAD_MEM_ADDR, "Invalid memory address"), \
423 C(BAD_IMM, "Invalid immediate value"), \
424 C(IMMSTR_NO_CLOSE, "String is not closed with '\"'"), \
425 C(FILE_ON_KPROBE, "File offset is not available with kprobe"), \
426 C(BAD_FILE_OFFS, "Invalid file offset value"), \
427 C(SYM_ON_UPROBE, "Symbol is not available with uprobe"), \
428 C(TOO_MANY_OPS, "Dereference is too much nested"), \
429 C(DEREF_NEED_BRACE, "Dereference needs a brace"), \
430 C(BAD_DEREF_OFFS, "Invalid dereference offset"), \
431 C(DEREF_OPEN_BRACE, "Dereference brace is not closed"), \
432 C(COMM_CANT_DEREF, "$comm can not be dereferenced"), \
433 C(BAD_FETCH_ARG, "Invalid fetch argument"), \
434 C(ARRAY_NO_CLOSE, "Array is not closed"), \
435 C(BAD_ARRAY_SUFFIX, "Array has wrong suffix"), \
436 C(BAD_ARRAY_NUM, "Invalid array size"), \
437 C(ARRAY_TOO_BIG, "Array number is too big"), \
438 C(BAD_TYPE, "Unknown type is specified"), \
439 C(BAD_STRING, "String accepts only memory argument"), \
440 C(BAD_SYMSTRING, "Symbol String doesn't accept data/userdata"), \
441 C(BAD_BITFIELD, "Invalid bitfield"), \
442 C(ARG_NAME_TOO_LONG, "Argument name is too long"), \
443 C(NO_ARG_NAME, "Argument name is not specified"), \
444 C(BAD_ARG_NAME, "Argument name must follow the same rules as C identifiers"), \
445 C(USED_ARG_NAME, "This argument name is already used"), \
446 C(ARG_TOO_LONG, "Argument expression is too long"), \
447 C(NO_ARG_BODY, "No argument expression"), \
448 C(BAD_INSN_BNDRY, "Probe point is not an instruction boundary"),\
449 C(FAIL_REG_PROBE, "Failed to register probe event"),\
450 C(DIFF_PROBE_TYPE, "Probe type is different from existing probe"),\
451 C(DIFF_ARG_TYPE, "Argument type or name is different from existing probe"),\
452 C(SAME_PROBE, "There is already the exact same probe event"),\
453 C(NO_EVENT_INFO, "This requires both group and event name to attach"),\
454 C(BAD_ATTACH_EVENT, "Attached event does not exist"),\
455 C(BAD_ATTACH_ARG, "Attached event does not have this field"),\
456 C(NO_EP_FILTER, "No filter rule after 'if'"),
457
458#undef C
459#define C(a, b) TP_ERR_##a
460
461/* Define TP_ERR_ */
462enum { ERRORS };
463
464/* Error text is defined in trace_probe.c */
465
466struct trace_probe_log {
467 const char *subsystem;
468 const char **argv;
469 int argc;
470 int index;
471};
472
473void trace_probe_log_init(const char *subsystem, int argc, const char **argv);
474void trace_probe_log_set_index(int index);
475void trace_probe_log_clear(void);
476void __trace_probe_log_err(int offset, int err);
477
478#define trace_probe_log_err(offs, err) \
479 __trace_probe_log_err(offs, TP_ERR_##err)