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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 <linux/btf.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_BTF_ARGS_LEN 128
37#define MAX_STRING_SIZE PATH_MAX
38#define MAX_ARG_BUF_LEN (MAX_TRACE_ARGS * MAX_ARG_NAME_LEN)
39
40/* Reserved field names */
41#define FIELD_STRING_IP "__probe_ip"
42#define FIELD_STRING_RETIP "__probe_ret_ip"
43#define FIELD_STRING_FUNC "__probe_func"
44
45#undef DEFINE_FIELD
46#define DEFINE_FIELD(type, item, name, is_signed) \
47 do { \
48 ret = trace_define_field(event_call, #type, name, \
49 offsetof(typeof(field), item), \
50 sizeof(field.item), is_signed, \
51 FILTER_OTHER); \
52 if (ret) \
53 return ret; \
54 } while (0)
55
56
57/* Flags for trace_probe */
58#define TP_FLAG_TRACE 1
59#define TP_FLAG_PROFILE 2
60
61/* data_loc: data location, compatible with u32 */
62#define make_data_loc(len, offs) \
63 (((u32)(len) << 16) | ((u32)(offs) & 0xffff))
64#define get_loc_len(dl) ((u32)(dl) >> 16)
65#define get_loc_offs(dl) ((u32)(dl) & 0xffff)
66
67static nokprobe_inline void *get_loc_data(u32 *dl, void *ent)
68{
69 return (u8 *)ent + get_loc_offs(*dl);
70}
71
72static nokprobe_inline u32 update_data_loc(u32 loc, int consumed)
73{
74 u32 maxlen = get_loc_len(loc);
75 u32 offset = get_loc_offs(loc);
76
77 return make_data_loc(maxlen - consumed, offset + consumed);
78}
79
80/* Printing function type */
81typedef int (*print_type_func_t)(struct trace_seq *, void *, void *);
82
83enum fetch_op {
84 FETCH_OP_NOP = 0,
85 // Stage 1 (load) ops
86 FETCH_OP_REG, /* Register : .param = offset */
87 FETCH_OP_STACK, /* Stack : .param = index */
88 FETCH_OP_STACKP, /* Stack pointer */
89 FETCH_OP_RETVAL, /* Return value */
90 FETCH_OP_IMM, /* Immediate : .immediate */
91 FETCH_OP_COMM, /* Current comm */
92 FETCH_OP_ARG, /* Function argument : .param */
93 FETCH_OP_FOFFS, /* File offset: .immediate */
94 FETCH_OP_DATA, /* Allocated data: .data */
95 // Stage 2 (dereference) op
96 FETCH_OP_DEREF, /* Dereference: .offset */
97 FETCH_OP_UDEREF, /* User-space Dereference: .offset */
98 // Stage 3 (store) ops
99 FETCH_OP_ST_RAW, /* Raw: .size */
100 FETCH_OP_ST_MEM, /* Mem: .offset, .size */
101 FETCH_OP_ST_UMEM, /* Mem: .offset, .size */
102 FETCH_OP_ST_STRING, /* String: .offset, .size */
103 FETCH_OP_ST_USTRING, /* User String: .offset, .size */
104 FETCH_OP_ST_SYMSTR, /* Kernel Symbol String: .offset, .size */
105 // Stage 4 (modify) op
106 FETCH_OP_MOD_BF, /* Bitfield: .basesize, .lshift, .rshift */
107 // Stage 5 (loop) op
108 FETCH_OP_LP_ARRAY, /* Array: .param = loop count */
109 FETCH_OP_TP_ARG, /* Trace Point argument */
110 FETCH_OP_END,
111 FETCH_NOP_SYMBOL, /* Unresolved Symbol holder */
112};
113
114struct fetch_insn {
115 enum fetch_op op;
116 union {
117 unsigned int param;
118 struct {
119 unsigned int size;
120 int offset;
121 };
122 struct {
123 unsigned char basesize;
124 unsigned char lshift;
125 unsigned char rshift;
126 };
127 unsigned long immediate;
128 void *data;
129 };
130};
131
132/* fetch + deref*N + store + mod + end <= 16, this allows N=12, enough */
133#define FETCH_INSN_MAX 16
134#define FETCH_TOKEN_COMM (-ECOMM)
135
136/* Fetch type information table */
137struct fetch_type {
138 const char *name; /* Name of type */
139 size_t size; /* Byte size of type */
140 bool is_signed; /* Signed flag */
141 bool is_string; /* String flag */
142 print_type_func_t print; /* Print functions */
143 const char *fmt; /* Format string */
144 const char *fmttype; /* Name in format file */
145};
146
147/* For defining macros, define string/string_size types */
148typedef u32 string;
149typedef u32 string_size;
150
151#define PRINT_TYPE_FUNC_NAME(type) print_type_##type
152#define PRINT_TYPE_FMT_NAME(type) print_type_format_##type
153
154/* Printing in basic type function template */
155#define DECLARE_BASIC_PRINT_TYPE_FUNC(type) \
156int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, void *data, void *ent);\
157extern const char PRINT_TYPE_FMT_NAME(type)[]
158
159DECLARE_BASIC_PRINT_TYPE_FUNC(u8);
160DECLARE_BASIC_PRINT_TYPE_FUNC(u16);
161DECLARE_BASIC_PRINT_TYPE_FUNC(u32);
162DECLARE_BASIC_PRINT_TYPE_FUNC(u64);
163DECLARE_BASIC_PRINT_TYPE_FUNC(s8);
164DECLARE_BASIC_PRINT_TYPE_FUNC(s16);
165DECLARE_BASIC_PRINT_TYPE_FUNC(s32);
166DECLARE_BASIC_PRINT_TYPE_FUNC(s64);
167DECLARE_BASIC_PRINT_TYPE_FUNC(x8);
168DECLARE_BASIC_PRINT_TYPE_FUNC(x16);
169DECLARE_BASIC_PRINT_TYPE_FUNC(x32);
170DECLARE_BASIC_PRINT_TYPE_FUNC(x64);
171
172DECLARE_BASIC_PRINT_TYPE_FUNC(char);
173DECLARE_BASIC_PRINT_TYPE_FUNC(string);
174DECLARE_BASIC_PRINT_TYPE_FUNC(symbol);
175
176/* Default (unsigned long) fetch type */
177#define __DEFAULT_FETCH_TYPE(t) x##t
178#define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t)
179#define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG)
180#define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE)
181
182#define __ADDR_FETCH_TYPE(t) u##t
183#define _ADDR_FETCH_TYPE(t) __ADDR_FETCH_TYPE(t)
184#define ADDR_FETCH_TYPE _ADDR_FETCH_TYPE(BITS_PER_LONG)
185
186#define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, str, _fmttype) \
187 {.name = _name, \
188 .size = _size, \
189 .is_signed = (bool)sign, \
190 .is_string = (bool)str, \
191 .print = PRINT_TYPE_FUNC_NAME(ptype), \
192 .fmt = PRINT_TYPE_FMT_NAME(ptype), \
193 .fmttype = _fmttype, \
194 }
195
196/* Non string types can use these macros */
197#define _ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \
198 __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, 0, #_fmttype)
199#define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \
200 _ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, ptype)
201
202/* If ptype is an alias of atype, use this macro (show atype in format) */
203#define ASSIGN_FETCH_TYPE_ALIAS(ptype, atype, ftype, sign) \
204 _ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, atype)
205
206#define ASSIGN_FETCH_TYPE_END {}
207#define MAX_ARRAY_LEN 64
208
209#ifdef CONFIG_KPROBE_EVENTS
210bool trace_kprobe_on_func_entry(struct trace_event_call *call);
211bool trace_kprobe_error_injectable(struct trace_event_call *call);
212#else
213static inline bool trace_kprobe_on_func_entry(struct trace_event_call *call)
214{
215 return false;
216}
217
218static inline bool trace_kprobe_error_injectable(struct trace_event_call *call)
219{
220 return false;
221}
222#endif /* CONFIG_KPROBE_EVENTS */
223
224struct probe_arg {
225 struct fetch_insn *code;
226 bool dynamic;/* Dynamic array (string) is used */
227 unsigned int offset; /* Offset from argument entry */
228 unsigned int count; /* Array count */
229 const char *name; /* Name of this argument */
230 const char *comm; /* Command of this argument */
231 char *fmt; /* Format string if needed */
232 const struct fetch_type *type; /* Type of this argument */
233};
234
235struct trace_uprobe_filter {
236 rwlock_t rwlock;
237 int nr_systemwide;
238 struct list_head perf_events;
239};
240
241/* Event call and class holder */
242struct trace_probe_event {
243 unsigned int flags; /* For TP_FLAG_* */
244 struct trace_event_class class;
245 struct trace_event_call call;
246 struct list_head files;
247 struct list_head probes;
248 struct trace_uprobe_filter filter[];
249};
250
251struct trace_probe {
252 struct list_head list;
253 struct trace_probe_event *event;
254 ssize_t size; /* trace entry size */
255 unsigned int nr_args;
256 struct probe_arg args[];
257};
258
259struct event_file_link {
260 struct trace_event_file *file;
261 struct list_head list;
262};
263
264static inline bool trace_probe_test_flag(struct trace_probe *tp,
265 unsigned int flag)
266{
267 return !!(tp->event->flags & flag);
268}
269
270static inline void trace_probe_set_flag(struct trace_probe *tp,
271 unsigned int flag)
272{
273 tp->event->flags |= flag;
274}
275
276static inline void trace_probe_clear_flag(struct trace_probe *tp,
277 unsigned int flag)
278{
279 tp->event->flags &= ~flag;
280}
281
282static inline bool trace_probe_is_enabled(struct trace_probe *tp)
283{
284 return trace_probe_test_flag(tp, TP_FLAG_TRACE | TP_FLAG_PROFILE);
285}
286
287static inline const char *trace_probe_name(struct trace_probe *tp)
288{
289 return trace_event_name(&tp->event->call);
290}
291
292static inline const char *trace_probe_group_name(struct trace_probe *tp)
293{
294 return tp->event->call.class->system;
295}
296
297static inline struct trace_event_call *
298 trace_probe_event_call(struct trace_probe *tp)
299{
300 return &tp->event->call;
301}
302
303static inline struct trace_probe_event *
304trace_probe_event_from_call(struct trace_event_call *event_call)
305{
306 return container_of(event_call, struct trace_probe_event, call);
307}
308
309static inline struct trace_probe *
310trace_probe_primary_from_call(struct trace_event_call *call)
311{
312 struct trace_probe_event *tpe = trace_probe_event_from_call(call);
313
314 return list_first_entry_or_null(&tpe->probes, struct trace_probe, list);
315}
316
317static inline struct list_head *trace_probe_probe_list(struct trace_probe *tp)
318{
319 return &tp->event->probes;
320}
321
322static inline bool trace_probe_has_sibling(struct trace_probe *tp)
323{
324 struct list_head *list = trace_probe_probe_list(tp);
325
326 return !list_empty(list) && !list_is_singular(list);
327}
328
329static inline int trace_probe_unregister_event_call(struct trace_probe *tp)
330{
331 /* tp->event is unregistered in trace_remove_event_call() */
332 return trace_remove_event_call(&tp->event->call);
333}
334
335static inline bool trace_probe_has_single_file(struct trace_probe *tp)
336{
337 return !!list_is_singular(&tp->event->files);
338}
339
340int trace_probe_init(struct trace_probe *tp, const char *event,
341 const char *group, bool alloc_filter);
342void trace_probe_cleanup(struct trace_probe *tp);
343int trace_probe_append(struct trace_probe *tp, struct trace_probe *to);
344void trace_probe_unlink(struct trace_probe *tp);
345int trace_probe_register_event_call(struct trace_probe *tp);
346int trace_probe_add_file(struct trace_probe *tp, struct trace_event_file *file);
347int trace_probe_remove_file(struct trace_probe *tp,
348 struct trace_event_file *file);
349struct event_file_link *trace_probe_get_file_link(struct trace_probe *tp,
350 struct trace_event_file *file);
351int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b);
352bool trace_probe_match_command_args(struct trace_probe *tp,
353 int argc, const char **argv);
354int trace_probe_create(const char *raw_command, int (*createfn)(int, const char **));
355int trace_probe_print_args(struct trace_seq *s, struct probe_arg *args, int nr_args,
356 u8 *data, void *field);
357
358#define trace_probe_for_each_link(pos, tp) \
359 list_for_each_entry(pos, &(tp)->event->files, list)
360#define trace_probe_for_each_link_rcu(pos, tp) \
361 list_for_each_entry_rcu(pos, &(tp)->event->files, list)
362
363/*
364 * The flags used for parsing trace_probe arguments.
365 * TPARG_FL_RETURN, TPARG_FL_FENTRY and TPARG_FL_TEVENT are mutually exclusive.
366 * TPARG_FL_KERNEL and TPARG_FL_USER are also mutually exclusive.
367 * TPARG_FL_FPROBE and TPARG_FL_TPOINT are optional but it should be with
368 * TPARG_FL_KERNEL.
369 */
370#define TPARG_FL_RETURN BIT(0)
371#define TPARG_FL_KERNEL BIT(1)
372#define TPARG_FL_FENTRY BIT(2)
373#define TPARG_FL_TEVENT BIT(3)
374#define TPARG_FL_USER BIT(4)
375#define TPARG_FL_FPROBE BIT(5)
376#define TPARG_FL_TPOINT BIT(6)
377#define TPARG_FL_LOC_MASK GENMASK(4, 0)
378
379static inline bool tparg_is_function_entry(unsigned int flags)
380{
381 return (flags & TPARG_FL_LOC_MASK) == (TPARG_FL_KERNEL | TPARG_FL_FENTRY);
382}
383
384struct traceprobe_parse_context {
385 struct trace_event_call *event;
386 /* BTF related parameters */
387 const char *funcname; /* Function name in BTF */
388 const struct btf_type *proto; /* Prototype of the function */
389 const struct btf_param *params; /* Parameter of the function */
390 s32 nr_params; /* The number of the parameters */
391 struct btf *btf; /* The BTF to be used */
392 const struct btf_type *last_type; /* Saved type */
393 u32 last_bitoffs; /* Saved bitoffs */
394 u32 last_bitsize; /* Saved bitsize */
395 unsigned int flags;
396 int offset;
397};
398
399extern int traceprobe_parse_probe_arg(struct trace_probe *tp, int i,
400 const char *argv,
401 struct traceprobe_parse_context *ctx);
402const char **traceprobe_expand_meta_args(int argc, const char *argv[],
403 int *new_argc, char *buf, int bufsize,
404 struct traceprobe_parse_context *ctx);
405
406extern int traceprobe_update_arg(struct probe_arg *arg);
407extern void traceprobe_free_probe_arg(struct probe_arg *arg);
408
409/*
410 * If either traceprobe_parse_probe_arg() or traceprobe_expand_meta_args() is called,
411 * this MUST be called for clean up the context and return a resource.
412 */
413void traceprobe_finish_parse(struct traceprobe_parse_context *ctx);
414
415extern int traceprobe_split_symbol_offset(char *symbol, long *offset);
416int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
417 char *buf, int offset);
418
419enum probe_print_type {
420 PROBE_PRINT_NORMAL,
421 PROBE_PRINT_RETURN,
422 PROBE_PRINT_EVENT,
423};
424
425extern int traceprobe_set_print_fmt(struct trace_probe *tp, enum probe_print_type ptype);
426
427#ifdef CONFIG_PERF_EVENTS
428extern struct trace_event_call *
429create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
430 bool is_return);
431extern void destroy_local_trace_kprobe(struct trace_event_call *event_call);
432
433extern struct trace_event_call *
434create_local_trace_uprobe(char *name, unsigned long offs,
435 unsigned long ref_ctr_offset, bool is_return);
436extern void destroy_local_trace_uprobe(struct trace_event_call *event_call);
437#endif
438extern int traceprobe_define_arg_fields(struct trace_event_call *event_call,
439 size_t offset, struct trace_probe *tp);
440
441#undef ERRORS
442#define ERRORS \
443 C(FILE_NOT_FOUND, "Failed to find the given file"), \
444 C(NO_REGULAR_FILE, "Not a regular file"), \
445 C(BAD_REFCNT, "Invalid reference counter offset"), \
446 C(REFCNT_OPEN_BRACE, "Reference counter brace is not closed"), \
447 C(BAD_REFCNT_SUFFIX, "Reference counter has wrong suffix"), \
448 C(BAD_UPROBE_OFFS, "Invalid uprobe offset"), \
449 C(BAD_MAXACT_TYPE, "Maxactive is only for function exit"), \
450 C(BAD_MAXACT, "Invalid maxactive number"), \
451 C(MAXACT_TOO_BIG, "Maxactive is too big"), \
452 C(BAD_PROBE_ADDR, "Invalid probed address or symbol"), \
453 C(NON_UNIQ_SYMBOL, "The symbol is not unique"), \
454 C(BAD_RETPROBE, "Retprobe address must be an function entry"), \
455 C(NO_TRACEPOINT, "Tracepoint is not found"), \
456 C(BAD_ADDR_SUFFIX, "Invalid probed address suffix"), \
457 C(NO_GROUP_NAME, "Group name is not specified"), \
458 C(GROUP_TOO_LONG, "Group name is too long"), \
459 C(BAD_GROUP_NAME, "Group name must follow the same rules as C identifiers"), \
460 C(NO_EVENT_NAME, "Event name is not specified"), \
461 C(EVENT_TOO_LONG, "Event name is too long"), \
462 C(BAD_EVENT_NAME, "Event name must follow the same rules as C identifiers"), \
463 C(EVENT_EXIST, "Given group/event name is already used by another event"), \
464 C(RETVAL_ON_PROBE, "$retval is not available on probe"), \
465 C(NO_RETVAL, "This function returns 'void' type"), \
466 C(BAD_STACK_NUM, "Invalid stack number"), \
467 C(BAD_ARG_NUM, "Invalid argument number"), \
468 C(BAD_VAR, "Invalid $-valiable specified"), \
469 C(BAD_REG_NAME, "Invalid register name"), \
470 C(BAD_MEM_ADDR, "Invalid memory address"), \
471 C(BAD_IMM, "Invalid immediate value"), \
472 C(IMMSTR_NO_CLOSE, "String is not closed with '\"'"), \
473 C(FILE_ON_KPROBE, "File offset is not available with kprobe"), \
474 C(BAD_FILE_OFFS, "Invalid file offset value"), \
475 C(SYM_ON_UPROBE, "Symbol is not available with uprobe"), \
476 C(TOO_MANY_OPS, "Dereference is too much nested"), \
477 C(DEREF_NEED_BRACE, "Dereference needs a brace"), \
478 C(BAD_DEREF_OFFS, "Invalid dereference offset"), \
479 C(DEREF_OPEN_BRACE, "Dereference brace is not closed"), \
480 C(COMM_CANT_DEREF, "$comm can not be dereferenced"), \
481 C(BAD_FETCH_ARG, "Invalid fetch argument"), \
482 C(ARRAY_NO_CLOSE, "Array is not closed"), \
483 C(BAD_ARRAY_SUFFIX, "Array has wrong suffix"), \
484 C(BAD_ARRAY_NUM, "Invalid array size"), \
485 C(ARRAY_TOO_BIG, "Array number is too big"), \
486 C(BAD_TYPE, "Unknown type is specified"), \
487 C(BAD_STRING, "String accepts only memory argument"), \
488 C(BAD_SYMSTRING, "Symbol String doesn't accept data/userdata"), \
489 C(BAD_BITFIELD, "Invalid bitfield"), \
490 C(ARG_NAME_TOO_LONG, "Argument name is too long"), \
491 C(NO_ARG_NAME, "Argument name is not specified"), \
492 C(BAD_ARG_NAME, "Argument name must follow the same rules as C identifiers"), \
493 C(USED_ARG_NAME, "This argument name is already used"), \
494 C(ARG_TOO_LONG, "Argument expression is too long"), \
495 C(NO_ARG_BODY, "No argument expression"), \
496 C(BAD_INSN_BNDRY, "Probe point is not an instruction boundary"),\
497 C(FAIL_REG_PROBE, "Failed to register probe event"),\
498 C(DIFF_PROBE_TYPE, "Probe type is different from existing probe"),\
499 C(DIFF_ARG_TYPE, "Argument type or name is different from existing probe"),\
500 C(SAME_PROBE, "There is already the exact same probe event"),\
501 C(NO_EVENT_INFO, "This requires both group and event name to attach"),\
502 C(BAD_ATTACH_EVENT, "Attached event does not exist"),\
503 C(BAD_ATTACH_ARG, "Attached event does not have this field"),\
504 C(NO_EP_FILTER, "No filter rule after 'if'"), \
505 C(NOSUP_BTFARG, "BTF is not available or not supported"), \
506 C(NO_BTFARG, "This variable is not found at this probe point"),\
507 C(NO_BTF_ENTRY, "No BTF entry for this probe point"), \
508 C(BAD_VAR_ARGS, "$arg* must be an independent parameter without name etc."),\
509 C(NOFENTRY_ARGS, "$arg* can be used only on function entry"), \
510 C(DOUBLE_ARGS, "$arg* can be used only once in the parameters"), \
511 C(ARGS_2LONG, "$arg* failed because the argument list is too long"), \
512 C(ARGIDX_2BIG, "$argN index is too big"), \
513 C(NO_PTR_STRCT, "This is not a pointer to union/structure."), \
514 C(NOSUP_DAT_ARG, "Non pointer structure/union argument is not supported."),\
515 C(BAD_HYPHEN, "Failed to parse single hyphen. Forgot '>'?"), \
516 C(NO_BTF_FIELD, "This field is not found."), \
517 C(BAD_BTF_TID, "Failed to get BTF type info."),\
518 C(BAD_TYPE4STR, "This type does not fit for string."),\
519 C(NEED_STRING_TYPE, "$comm and immediate-string only accepts string type"),
520
521#undef C
522#define C(a, b) TP_ERR_##a
523
524/* Define TP_ERR_ */
525enum { ERRORS };
526
527/* Error text is defined in trace_probe.c */
528
529struct trace_probe_log {
530 const char *subsystem;
531 const char **argv;
532 int argc;
533 int index;
534};
535
536void trace_probe_log_init(const char *subsystem, int argc, const char **argv);
537void trace_probe_log_set_index(int index);
538void trace_probe_log_clear(void);
539void __trace_probe_log_err(int offset, int err);
540
541#define trace_probe_log_err(offs, err) \
542 __trace_probe_log_err(offs, TP_ERR_##err)
543
544struct uprobe_dispatch_data {
545 struct trace_uprobe *tu;
546 unsigned long bp_addr;
547};
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
65static nokprobe_inline void *get_loc_data(u32 *dl, void *ent)
66{
67 return (u8 *)ent + get_loc_offs(*dl);
68}
69
70static 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 */
79typedef int (*print_type_func_t)(struct trace_seq *, void *, void *);
80
81enum 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
110struct 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 */
133struct 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 */
143typedef u32 string;
144typedef 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) \
151int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, void *data, void *ent);\
152extern const char PRINT_TYPE_FMT_NAME(type)[]
153
154DECLARE_BASIC_PRINT_TYPE_FUNC(u8);
155DECLARE_BASIC_PRINT_TYPE_FUNC(u16);
156DECLARE_BASIC_PRINT_TYPE_FUNC(u32);
157DECLARE_BASIC_PRINT_TYPE_FUNC(u64);
158DECLARE_BASIC_PRINT_TYPE_FUNC(s8);
159DECLARE_BASIC_PRINT_TYPE_FUNC(s16);
160DECLARE_BASIC_PRINT_TYPE_FUNC(s32);
161DECLARE_BASIC_PRINT_TYPE_FUNC(s64);
162DECLARE_BASIC_PRINT_TYPE_FUNC(x8);
163DECLARE_BASIC_PRINT_TYPE_FUNC(x16);
164DECLARE_BASIC_PRINT_TYPE_FUNC(x32);
165DECLARE_BASIC_PRINT_TYPE_FUNC(x64);
166
167DECLARE_BASIC_PRINT_TYPE_FUNC(string);
168DECLARE_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
201bool trace_kprobe_on_func_entry(struct trace_event_call *call);
202bool trace_kprobe_error_injectable(struct trace_event_call *call);
203#else
204static inline bool trace_kprobe_on_func_entry(struct trace_event_call *call)
205{
206 return false;
207}
208
209static inline bool trace_kprobe_error_injectable(struct trace_event_call *call)
210{
211 return false;
212}
213#endif /* CONFIG_KPROBE_EVENTS */
214
215struct 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 */
227struct 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};
234
235struct trace_probe {
236 struct list_head list;
237 struct trace_probe_event *event;
238 ssize_t size; /* trace entry size */
239 unsigned int nr_args;
240 struct probe_arg args[];
241};
242
243struct event_file_link {
244 struct trace_event_file *file;
245 struct list_head list;
246};
247
248static inline bool trace_probe_test_flag(struct trace_probe *tp,
249 unsigned int flag)
250{
251 return !!(tp->event->flags & flag);
252}
253
254static inline void trace_probe_set_flag(struct trace_probe *tp,
255 unsigned int flag)
256{
257 tp->event->flags |= flag;
258}
259
260static inline void trace_probe_clear_flag(struct trace_probe *tp,
261 unsigned int flag)
262{
263 tp->event->flags &= ~flag;
264}
265
266static inline bool trace_probe_is_enabled(struct trace_probe *tp)
267{
268 return trace_probe_test_flag(tp, TP_FLAG_TRACE | TP_FLAG_PROFILE);
269}
270
271static inline const char *trace_probe_name(struct trace_probe *tp)
272{
273 return trace_event_name(&tp->event->call);
274}
275
276static inline const char *trace_probe_group_name(struct trace_probe *tp)
277{
278 return tp->event->call.class->system;
279}
280
281static inline struct trace_event_call *
282 trace_probe_event_call(struct trace_probe *tp)
283{
284 return &tp->event->call;
285}
286
287static inline struct trace_probe_event *
288trace_probe_event_from_call(struct trace_event_call *event_call)
289{
290 return container_of(event_call, struct trace_probe_event, call);
291}
292
293static inline struct trace_probe *
294trace_probe_primary_from_call(struct trace_event_call *call)
295{
296 struct trace_probe_event *tpe = trace_probe_event_from_call(call);
297
298 return list_first_entry(&tpe->probes, struct trace_probe, list);
299}
300
301static inline struct list_head *trace_probe_probe_list(struct trace_probe *tp)
302{
303 return &tp->event->probes;
304}
305
306static inline bool trace_probe_has_sibling(struct trace_probe *tp)
307{
308 struct list_head *list = trace_probe_probe_list(tp);
309
310 return !list_empty(list) && !list_is_singular(list);
311}
312
313static inline int trace_probe_unregister_event_call(struct trace_probe *tp)
314{
315 /* tp->event is unregistered in trace_remove_event_call() */
316 return trace_remove_event_call(&tp->event->call);
317}
318
319static inline bool trace_probe_has_single_file(struct trace_probe *tp)
320{
321 return !!list_is_singular(&tp->event->files);
322}
323
324int trace_probe_init(struct trace_probe *tp, const char *event,
325 const char *group);
326void trace_probe_cleanup(struct trace_probe *tp);
327int trace_probe_append(struct trace_probe *tp, struct trace_probe *to);
328void trace_probe_unlink(struct trace_probe *tp);
329int trace_probe_register_event_call(struct trace_probe *tp);
330int trace_probe_add_file(struct trace_probe *tp, struct trace_event_file *file);
331int trace_probe_remove_file(struct trace_probe *tp,
332 struct trace_event_file *file);
333struct event_file_link *trace_probe_get_file_link(struct trace_probe *tp,
334 struct trace_event_file *file);
335int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b);
336bool trace_probe_match_command_args(struct trace_probe *tp,
337 int argc, const char **argv);
338
339#define trace_probe_for_each_link(pos, tp) \
340 list_for_each_entry(pos, &(tp)->event->files, list)
341#define trace_probe_for_each_link_rcu(pos, tp) \
342 list_for_each_entry_rcu(pos, &(tp)->event->files, list)
343
344/* Check the name is good for event/group/fields */
345static inline bool is_good_name(const char *name)
346{
347 if (!isalpha(*name) && *name != '_')
348 return false;
349 while (*++name != '\0') {
350 if (!isalpha(*name) && !isdigit(*name) && *name != '_')
351 return false;
352 }
353 return true;
354}
355
356#define TPARG_FL_RETURN BIT(0)
357#define TPARG_FL_KERNEL BIT(1)
358#define TPARG_FL_FENTRY BIT(2)
359#define TPARG_FL_MASK GENMASK(2, 0)
360
361extern int traceprobe_parse_probe_arg(struct trace_probe *tp, int i,
362 char *arg, unsigned int flags);
363
364extern int traceprobe_update_arg(struct probe_arg *arg);
365extern void traceprobe_free_probe_arg(struct probe_arg *arg);
366
367extern int traceprobe_split_symbol_offset(char *symbol, long *offset);
368int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
369 char *buf, int offset);
370
371extern int traceprobe_set_print_fmt(struct trace_probe *tp, bool is_return);
372
373#ifdef CONFIG_PERF_EVENTS
374extern struct trace_event_call *
375create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
376 bool is_return);
377extern void destroy_local_trace_kprobe(struct trace_event_call *event_call);
378
379extern struct trace_event_call *
380create_local_trace_uprobe(char *name, unsigned long offs,
381 unsigned long ref_ctr_offset, bool is_return);
382extern void destroy_local_trace_uprobe(struct trace_event_call *event_call);
383#endif
384extern int traceprobe_define_arg_fields(struct trace_event_call *event_call,
385 size_t offset, struct trace_probe *tp);
386
387#undef ERRORS
388#define ERRORS \
389 C(FILE_NOT_FOUND, "Failed to find the given file"), \
390 C(NO_REGULAR_FILE, "Not a regular file"), \
391 C(BAD_REFCNT, "Invalid reference counter offset"), \
392 C(REFCNT_OPEN_BRACE, "Reference counter brace is not closed"), \
393 C(BAD_REFCNT_SUFFIX, "Reference counter has wrong suffix"), \
394 C(BAD_UPROBE_OFFS, "Invalid uprobe offset"), \
395 C(MAXACT_NO_KPROBE, "Maxactive is not for kprobe"), \
396 C(BAD_MAXACT, "Invalid maxactive number"), \
397 C(MAXACT_TOO_BIG, "Maxactive is too big"), \
398 C(BAD_PROBE_ADDR, "Invalid probed address or symbol"), \
399 C(BAD_RETPROBE, "Retprobe address must be an function entry"), \
400 C(NO_GROUP_NAME, "Group name is not specified"), \
401 C(GROUP_TOO_LONG, "Group name is too long"), \
402 C(BAD_GROUP_NAME, "Group name must follow the same rules as C identifiers"), \
403 C(NO_EVENT_NAME, "Event name is not specified"), \
404 C(EVENT_TOO_LONG, "Event name is too long"), \
405 C(BAD_EVENT_NAME, "Event name must follow the same rules as C identifiers"), \
406 C(RETVAL_ON_PROBE, "$retval is not available on probe"), \
407 C(BAD_STACK_NUM, "Invalid stack number"), \
408 C(BAD_ARG_NUM, "Invalid argument number"), \
409 C(BAD_VAR, "Invalid $-valiable specified"), \
410 C(BAD_REG_NAME, "Invalid register name"), \
411 C(BAD_MEM_ADDR, "Invalid memory address"), \
412 C(BAD_IMM, "Invalid immediate value"), \
413 C(IMMSTR_NO_CLOSE, "String is not closed with '\"'"), \
414 C(FILE_ON_KPROBE, "File offset is not available with kprobe"), \
415 C(BAD_FILE_OFFS, "Invalid file offset value"), \
416 C(SYM_ON_UPROBE, "Symbol is not available with uprobe"), \
417 C(TOO_MANY_OPS, "Dereference is too much nested"), \
418 C(DEREF_NEED_BRACE, "Dereference needs a brace"), \
419 C(BAD_DEREF_OFFS, "Invalid dereference offset"), \
420 C(DEREF_OPEN_BRACE, "Dereference brace is not closed"), \
421 C(COMM_CANT_DEREF, "$comm can not be dereferenced"), \
422 C(BAD_FETCH_ARG, "Invalid fetch argument"), \
423 C(ARRAY_NO_CLOSE, "Array is not closed"), \
424 C(BAD_ARRAY_SUFFIX, "Array has wrong suffix"), \
425 C(BAD_ARRAY_NUM, "Invalid array size"), \
426 C(ARRAY_TOO_BIG, "Array number is too big"), \
427 C(BAD_TYPE, "Unknown type is specified"), \
428 C(BAD_STRING, "String accepts only memory argument"), \
429 C(BAD_BITFIELD, "Invalid bitfield"), \
430 C(ARG_NAME_TOO_LONG, "Argument name is too long"), \
431 C(NO_ARG_NAME, "Argument name is not specified"), \
432 C(BAD_ARG_NAME, "Argument name must follow the same rules as C identifiers"), \
433 C(USED_ARG_NAME, "This argument name is already used"), \
434 C(ARG_TOO_LONG, "Argument expression is too long"), \
435 C(NO_ARG_BODY, "No argument expression"), \
436 C(BAD_INSN_BNDRY, "Probe point is not an instruction boundary"),\
437 C(FAIL_REG_PROBE, "Failed to register probe event"),\
438 C(DIFF_PROBE_TYPE, "Probe type is different from existing probe"),\
439 C(DIFF_ARG_TYPE, "Argument type or name is different from existing probe"),\
440 C(SAME_PROBE, "There is already the exact same probe event"),
441
442#undef C
443#define C(a, b) TP_ERR_##a
444
445/* Define TP_ERR_ */
446enum { ERRORS };
447
448/* Error text is defined in trace_probe.c */
449
450struct trace_probe_log {
451 const char *subsystem;
452 const char **argv;
453 int argc;
454 int index;
455};
456
457void trace_probe_log_init(const char *subsystem, int argc, const char **argv);
458void trace_probe_log_set_index(int index);
459void trace_probe_log_clear(void);
460void __trace_probe_log_err(int offset, int err);
461
462#define trace_probe_log_err(offs, err) \
463 __trace_probe_log_err(offs, TP_ERR_##err)