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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/*
2 * Common header file for probe-based Dynamic events.
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License
14 * along with this program; if not, write to the Free Software
15 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
16 *
17 * This code was copied from kernel/trace/trace_kprobe.h written by
18 * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
19 *
20 * Updates to make this generic:
21 * Copyright (C) IBM Corporation, 2010-2011
22 * Author: Srikar Dronamraju
23 */
24
25#include <linux/seq_file.h>
26#include <linux/slab.h>
27#include <linux/smp.h>
28#include <linux/tracefs.h>
29#include <linux/types.h>
30#include <linux/string.h>
31#include <linux/ctype.h>
32#include <linux/ptrace.h>
33#include <linux/perf_event.h>
34#include <linux/kprobes.h>
35#include <linux/stringify.h>
36#include <linux/limits.h>
37#include <linux/uaccess.h>
38#include <asm/bitsperlong.h>
39
40#include "trace.h"
41#include "trace_output.h"
42
43#define MAX_TRACE_ARGS 128
44#define MAX_ARGSTR_LEN 63
45#define MAX_EVENT_NAME_LEN 64
46#define MAX_STRING_SIZE PATH_MAX
47
48/* Reserved field names */
49#define FIELD_STRING_IP "__probe_ip"
50#define FIELD_STRING_RETIP "__probe_ret_ip"
51#define FIELD_STRING_FUNC "__probe_func"
52
53#undef DEFINE_FIELD
54#define DEFINE_FIELD(type, item, name, is_signed) \
55 do { \
56 ret = trace_define_field(event_call, #type, name, \
57 offsetof(typeof(field), item), \
58 sizeof(field.item), is_signed, \
59 FILTER_OTHER); \
60 if (ret) \
61 return ret; \
62 } while (0)
63
64
65/* Flags for trace_probe */
66#define TP_FLAG_TRACE 1
67#define TP_FLAG_PROFILE 2
68#define TP_FLAG_REGISTERED 4
69
70
71/* data_rloc: data relative location, compatible with u32 */
72#define make_data_rloc(len, roffs) \
73 (((u32)(len) << 16) | ((u32)(roffs) & 0xffff))
74#define get_rloc_len(dl) ((u32)(dl) >> 16)
75#define get_rloc_offs(dl) ((u32)(dl) & 0xffff)
76
77/*
78 * Convert data_rloc to data_loc:
79 * data_rloc stores the offset from data_rloc itself, but data_loc
80 * stores the offset from event entry.
81 */
82#define convert_rloc_to_loc(dl, offs) ((u32)(dl) + (offs))
83
84static nokprobe_inline void *get_rloc_data(u32 *dl)
85{
86 return (u8 *)dl + get_rloc_offs(*dl);
87}
88
89/* For data_loc conversion */
90static nokprobe_inline void *get_loc_data(u32 *dl, void *ent)
91{
92 return (u8 *)ent + get_rloc_offs(*dl);
93}
94
95/* Data fetch function type */
96typedef void (*fetch_func_t)(struct pt_regs *, void *, void *);
97/* Printing function type */
98typedef int (*print_type_func_t)(struct trace_seq *, const char *, void *, void *);
99
100/* Fetch types */
101enum {
102 FETCH_MTD_reg = 0,
103 FETCH_MTD_stack,
104 FETCH_MTD_retval,
105 FETCH_MTD_comm,
106 FETCH_MTD_memory,
107 FETCH_MTD_symbol,
108 FETCH_MTD_deref,
109 FETCH_MTD_bitfield,
110 FETCH_MTD_file_offset,
111 FETCH_MTD_END,
112};
113
114/* Fetch type information table */
115struct fetch_type {
116 const char *name; /* Name of type */
117 size_t size; /* Byte size of type */
118 int is_signed; /* Signed flag */
119 print_type_func_t print; /* Print functions */
120 const char *fmt; /* Fromat string */
121 const char *fmttype; /* Name in format file */
122 /* Fetch functions */
123 fetch_func_t fetch[FETCH_MTD_END];
124};
125
126struct fetch_param {
127 fetch_func_t fn;
128 void *data;
129};
130
131/* For defining macros, define string/string_size types */
132typedef u32 string;
133typedef u32 string_size;
134
135#define PRINT_TYPE_FUNC_NAME(type) print_type_##type
136#define PRINT_TYPE_FMT_NAME(type) print_type_format_##type
137
138/* Printing in basic type function template */
139#define DECLARE_BASIC_PRINT_TYPE_FUNC(type) \
140int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, const char *name, \
141 void *data, void *ent); \
142extern const char PRINT_TYPE_FMT_NAME(type)[]
143
144DECLARE_BASIC_PRINT_TYPE_FUNC(u8);
145DECLARE_BASIC_PRINT_TYPE_FUNC(u16);
146DECLARE_BASIC_PRINT_TYPE_FUNC(u32);
147DECLARE_BASIC_PRINT_TYPE_FUNC(u64);
148DECLARE_BASIC_PRINT_TYPE_FUNC(s8);
149DECLARE_BASIC_PRINT_TYPE_FUNC(s16);
150DECLARE_BASIC_PRINT_TYPE_FUNC(s32);
151DECLARE_BASIC_PRINT_TYPE_FUNC(s64);
152DECLARE_BASIC_PRINT_TYPE_FUNC(x8);
153DECLARE_BASIC_PRINT_TYPE_FUNC(x16);
154DECLARE_BASIC_PRINT_TYPE_FUNC(x32);
155DECLARE_BASIC_PRINT_TYPE_FUNC(x64);
156
157DECLARE_BASIC_PRINT_TYPE_FUNC(string);
158
159#define FETCH_FUNC_NAME(method, type) fetch_##method##_##type
160
161/* Declare macro for basic types */
162#define DECLARE_FETCH_FUNC(method, type) \
163extern void FETCH_FUNC_NAME(method, type)(struct pt_regs *regs, \
164 void *data, void *dest)
165
166#define DECLARE_BASIC_FETCH_FUNCS(method) \
167DECLARE_FETCH_FUNC(method, u8); \
168DECLARE_FETCH_FUNC(method, u16); \
169DECLARE_FETCH_FUNC(method, u32); \
170DECLARE_FETCH_FUNC(method, u64)
171
172DECLARE_BASIC_FETCH_FUNCS(reg);
173#define fetch_reg_string NULL
174#define fetch_reg_string_size NULL
175
176DECLARE_BASIC_FETCH_FUNCS(retval);
177#define fetch_retval_string NULL
178#define fetch_retval_string_size NULL
179
180DECLARE_BASIC_FETCH_FUNCS(symbol);
181DECLARE_FETCH_FUNC(symbol, string);
182DECLARE_FETCH_FUNC(symbol, string_size);
183
184DECLARE_BASIC_FETCH_FUNCS(deref);
185DECLARE_FETCH_FUNC(deref, string);
186DECLARE_FETCH_FUNC(deref, string_size);
187
188DECLARE_BASIC_FETCH_FUNCS(bitfield);
189#define fetch_bitfield_string NULL
190#define fetch_bitfield_string_size NULL
191
192/* comm only makes sense as a string */
193#define fetch_comm_u8 NULL
194#define fetch_comm_u16 NULL
195#define fetch_comm_u32 NULL
196#define fetch_comm_u64 NULL
197DECLARE_FETCH_FUNC(comm, string);
198DECLARE_FETCH_FUNC(comm, string_size);
199
200/*
201 * Define macro for basic types - we don't need to define s* types, because
202 * we have to care only about bitwidth at recording time.
203 */
204#define DEFINE_BASIC_FETCH_FUNCS(method) \
205DEFINE_FETCH_##method(u8) \
206DEFINE_FETCH_##method(u16) \
207DEFINE_FETCH_##method(u32) \
208DEFINE_FETCH_##method(u64)
209
210/* Default (unsigned long) fetch type */
211#define __DEFAULT_FETCH_TYPE(t) x##t
212#define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t)
213#define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG)
214#define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE)
215
216#define ASSIGN_FETCH_FUNC(method, type) \
217 [FETCH_MTD_##method] = FETCH_FUNC_NAME(method, type)
218
219#define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \
220 {.name = _name, \
221 .size = _size, \
222 .is_signed = sign, \
223 .print = PRINT_TYPE_FUNC_NAME(ptype), \
224 .fmt = PRINT_TYPE_FMT_NAME(ptype), \
225 .fmttype = _fmttype, \
226 .fetch = { \
227ASSIGN_FETCH_FUNC(reg, ftype), \
228ASSIGN_FETCH_FUNC(stack, ftype), \
229ASSIGN_FETCH_FUNC(retval, ftype), \
230ASSIGN_FETCH_FUNC(comm, ftype), \
231ASSIGN_FETCH_FUNC(memory, ftype), \
232ASSIGN_FETCH_FUNC(symbol, ftype), \
233ASSIGN_FETCH_FUNC(deref, ftype), \
234ASSIGN_FETCH_FUNC(bitfield, ftype), \
235ASSIGN_FETCH_FUNC(file_offset, ftype), \
236 } \
237 }
238
239#define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \
240 __ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #ptype)
241
242/* If ptype is an alias of atype, use this macro (show atype in format) */
243#define ASSIGN_FETCH_TYPE_ALIAS(ptype, atype, ftype, sign) \
244 __ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #atype)
245
246#define ASSIGN_FETCH_TYPE_END {}
247
248#define FETCH_TYPE_STRING 0
249#define FETCH_TYPE_STRSIZE 1
250
251#ifdef CONFIG_KPROBE_EVENT
252struct symbol_cache;
253unsigned long update_symbol_cache(struct symbol_cache *sc);
254void free_symbol_cache(struct symbol_cache *sc);
255struct symbol_cache *alloc_symbol_cache(const char *sym, long offset);
256#else
257/* uprobes do not support symbol fetch methods */
258#define fetch_symbol_u8 NULL
259#define fetch_symbol_u16 NULL
260#define fetch_symbol_u32 NULL
261#define fetch_symbol_u64 NULL
262#define fetch_symbol_string NULL
263#define fetch_symbol_string_size NULL
264
265struct symbol_cache {
266};
267static inline unsigned long __used update_symbol_cache(struct symbol_cache *sc)
268{
269 return 0;
270}
271
272static inline void __used free_symbol_cache(struct symbol_cache *sc)
273{
274}
275
276static inline struct symbol_cache * __used
277alloc_symbol_cache(const char *sym, long offset)
278{
279 return NULL;
280}
281#endif /* CONFIG_KPROBE_EVENT */
282
283struct probe_arg {
284 struct fetch_param fetch;
285 struct fetch_param fetch_size;
286 unsigned int offset; /* Offset from argument entry */
287 const char *name; /* Name of this argument */
288 const char *comm; /* Command of this argument */
289 const struct fetch_type *type; /* Type of this argument */
290};
291
292struct trace_probe {
293 unsigned int flags; /* For TP_FLAG_* */
294 struct trace_event_class class;
295 struct trace_event_call call;
296 struct list_head files;
297 ssize_t size; /* trace entry size */
298 unsigned int nr_args;
299 struct probe_arg args[];
300};
301
302struct event_file_link {
303 struct trace_event_file *file;
304 struct list_head list;
305};
306
307static inline bool trace_probe_is_enabled(struct trace_probe *tp)
308{
309 return !!(tp->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE));
310}
311
312static inline bool trace_probe_is_registered(struct trace_probe *tp)
313{
314 return !!(tp->flags & TP_FLAG_REGISTERED);
315}
316
317static nokprobe_inline void call_fetch(struct fetch_param *fprm,
318 struct pt_regs *regs, void *dest)
319{
320 return fprm->fn(regs, fprm->data, dest);
321}
322
323/* Check the name is good for event/group/fields */
324static inline bool is_good_name(const char *name)
325{
326 if (!isalpha(*name) && *name != '_')
327 return false;
328 while (*++name != '\0') {
329 if (!isalpha(*name) && !isdigit(*name) && *name != '_')
330 return false;
331 }
332 return true;
333}
334
335static inline struct event_file_link *
336find_event_file_link(struct trace_probe *tp, struct trace_event_file *file)
337{
338 struct event_file_link *link;
339
340 list_for_each_entry(link, &tp->files, list)
341 if (link->file == file)
342 return link;
343
344 return NULL;
345}
346
347extern int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
348 struct probe_arg *parg, bool is_return, bool is_kprobe,
349 const struct fetch_type *ftbl);
350
351extern int traceprobe_conflict_field_name(const char *name,
352 struct probe_arg *args, int narg);
353
354extern void traceprobe_update_arg(struct probe_arg *arg);
355extern void traceprobe_free_probe_arg(struct probe_arg *arg);
356
357extern int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset);
358
359extern ssize_t traceprobe_probes_write(struct file *file,
360 const char __user *buffer, size_t count, loff_t *ppos,
361 int (*createfn)(int, char**));
362
363extern int traceprobe_command(const char *buf, int (*createfn)(int, char**));
364
365/* Sum up total data length for dynamic arraies (strings) */
366static nokprobe_inline int
367__get_data_size(struct trace_probe *tp, struct pt_regs *regs)
368{
369 int i, ret = 0;
370 u32 len;
371
372 for (i = 0; i < tp->nr_args; i++)
373 if (unlikely(tp->args[i].fetch_size.fn)) {
374 call_fetch(&tp->args[i].fetch_size, regs, &len);
375 ret += len;
376 }
377
378 return ret;
379}
380
381/* Store the value of each argument */
382static nokprobe_inline void
383store_trace_args(int ent_size, struct trace_probe *tp, struct pt_regs *regs,
384 u8 *data, int maxlen)
385{
386 int i;
387 u32 end = tp->size;
388 u32 *dl; /* Data (relative) location */
389
390 for (i = 0; i < tp->nr_args; i++) {
391 if (unlikely(tp->args[i].fetch_size.fn)) {
392 /*
393 * First, we set the relative location and
394 * maximum data length to *dl
395 */
396 dl = (u32 *)(data + tp->args[i].offset);
397 *dl = make_data_rloc(maxlen, end - tp->args[i].offset);
398 /* Then try to fetch string or dynamic array data */
399 call_fetch(&tp->args[i].fetch, regs, dl);
400 /* Reduce maximum length */
401 end += get_rloc_len(*dl);
402 maxlen -= get_rloc_len(*dl);
403 /* Trick here, convert data_rloc to data_loc */
404 *dl = convert_rloc_to_loc(*dl,
405 ent_size + tp->args[i].offset);
406 } else
407 /* Just fetching data normally */
408 call_fetch(&tp->args[i].fetch, regs,
409 data + tp->args[i].offset);
410 }
411}
412
413extern int set_print_fmt(struct trace_probe *tp, bool is_return);