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Merge remote-tracking branch 'moduleh/module.h-split'
[linux-2.6/next.git] / kernel / trace / trace_kprobe.c
blob5fb3697bf0e5e982882d208d2321c67dd0edf5c8
1 /*
2 * Kprobes-based tracing events
3 *
4 * Created by Masami Hiramatsu <mhiramat@redhat.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19
20 #include <linux/module.h>
21 #include <linux/uaccess.h>
22 #include <linux/kprobes.h>
23 #include <linux/seq_file.h>
24 #include <linux/slab.h>
25 #include <linux/smp.h>
26 #include <linux/debugfs.h>
27 #include <linux/types.h>
28 #include <linux/string.h>
29 #include <linux/ctype.h>
30 #include <linux/ptrace.h>
31 #include <linux/perf_event.h>
32 #include <linux/stringify.h>
33 #include <linux/limits.h>
34 #include <asm/bitsperlong.h>
35
36 #include "trace.h"
37 #include "trace_output.h"
38
39 #define MAX_TRACE_ARGS 128
40 #define MAX_ARGSTR_LEN 63
41 #define MAX_EVENT_NAME_LEN 64
42 #define MAX_STRING_SIZE PATH_MAX
43 #define KPROBE_EVENT_SYSTEM "kprobes"
44
45 /* Reserved field names */
46 #define FIELD_STRING_IP "__probe_ip"
47 #define FIELD_STRING_RETIP "__probe_ret_ip"
48 #define FIELD_STRING_FUNC "__probe_func"
49
50 const char *reserved_field_names[] = {
51 "common_type",
52 "common_flags",
53 "common_preempt_count",
54 "common_pid",
55 "common_tgid",
56 FIELD_STRING_IP,
57 FIELD_STRING_RETIP,
58 FIELD_STRING_FUNC,
59 };
60
61 /* Printing function type */
62 typedef int (*print_type_func_t)(struct trace_seq *, const char *, void *,
63 void *);
64 #define PRINT_TYPE_FUNC_NAME(type) print_type_##type
65 #define PRINT_TYPE_FMT_NAME(type) print_type_format_##type
66
67 /* Printing in basic type function template */
68 #define DEFINE_BASIC_PRINT_TYPE_FUNC(type, fmt, cast) \
69 static __kprobes int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, \
70 const char *name, \
71 void *data, void *ent)\
72 { \
73 return trace_seq_printf(s, " %s=" fmt, name, (cast)*(type *)data);\
74 } \
75 static const char PRINT_TYPE_FMT_NAME(type)[] = fmt;
76
77 DEFINE_BASIC_PRINT_TYPE_FUNC(u8, "%x", unsigned int)
78 DEFINE_BASIC_PRINT_TYPE_FUNC(u16, "%x", unsigned int)
79 DEFINE_BASIC_PRINT_TYPE_FUNC(u32, "%lx", unsigned long)
80 DEFINE_BASIC_PRINT_TYPE_FUNC(u64, "%llx", unsigned long long)
81 DEFINE_BASIC_PRINT_TYPE_FUNC(s8, "%d", int)
82 DEFINE_BASIC_PRINT_TYPE_FUNC(s16, "%d", int)
83 DEFINE_BASIC_PRINT_TYPE_FUNC(s32, "%ld", long)
84 DEFINE_BASIC_PRINT_TYPE_FUNC(s64, "%lld", long long)
85
86 /* data_rloc: data relative location, compatible with u32 */
87 #define make_data_rloc(len, roffs) \
88 (((u32)(len) << 16) | ((u32)(roffs) & 0xffff))
89 #define get_rloc_len(dl) ((u32)(dl) >> 16)
90 #define get_rloc_offs(dl) ((u32)(dl) & 0xffff)
91
92 static inline void *get_rloc_data(u32 *dl)
93 {
94 return (u8 *)dl + get_rloc_offs(*dl);
95 }
96
97 /* For data_loc conversion */
98 static inline void *get_loc_data(u32 *dl, void *ent)
99 {
100 return (u8 *)ent + get_rloc_offs(*dl);
101 }
102
103 /*
104 * Convert data_rloc to data_loc:
105 * data_rloc stores the offset from data_rloc itself, but data_loc
106 * stores the offset from event entry.
107 */
108 #define convert_rloc_to_loc(dl, offs) ((u32)(dl) + (offs))
109
110 /* For defining macros, define string/string_size types */
111 typedef u32 string;
112 typedef u32 string_size;
113
114 /* Print type function for string type */
115 static __kprobes int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s,
116 const char *name,
117 void *data, void *ent)
118 {
119 int len = *(u32 *)data >> 16;
120
121 if (!len)
122 return trace_seq_printf(s, " %s=(fault)", name);
123 else
124 return trace_seq_printf(s, " %s=\"%s\"", name,
125 (const char *)get_loc_data(data, ent));
126 }
127 static const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\"";
128
129 /* Data fetch function type */
130 typedef void (*fetch_func_t)(struct pt_regs *, void *, void *);
131
132 struct fetch_param {
133 fetch_func_t fn;
134 void *data;
135 };
136
137 static __kprobes void call_fetch(struct fetch_param *fprm,
138 struct pt_regs *regs, void *dest)
139 {
140 return fprm->fn(regs, fprm->data, dest);
141 }
142
143 #define FETCH_FUNC_NAME(method, type) fetch_##method##_##type
144 /*
145 * Define macro for basic types - we don't need to define s* types, because
146 * we have to care only about bitwidth at recording time.
147 */
148 #define DEFINE_BASIC_FETCH_FUNCS(method) \
149 DEFINE_FETCH_##method(u8) \
150 DEFINE_FETCH_##method(u16) \
151 DEFINE_FETCH_##method(u32) \
152 DEFINE_FETCH_##method(u64)
153
154 #define CHECK_FETCH_FUNCS(method, fn) \
155 (((FETCH_FUNC_NAME(method, u8) == fn) || \
156 (FETCH_FUNC_NAME(method, u16) == fn) || \
157 (FETCH_FUNC_NAME(method, u32) == fn) || \
158 (FETCH_FUNC_NAME(method, u64) == fn) || \
159 (FETCH_FUNC_NAME(method, string) == fn) || \
160 (FETCH_FUNC_NAME(method, string_size) == fn)) \
161 && (fn != NULL))
162
163 /* Data fetch function templates */
164 #define DEFINE_FETCH_reg(type) \
165 static __kprobes void FETCH_FUNC_NAME(reg, type)(struct pt_regs *regs, \
166 void *offset, void *dest) \
167 { \
168 *(type *)dest = (type)regs_get_register(regs, \
169 (unsigned int)((unsigned long)offset)); \
170 }
171 DEFINE_BASIC_FETCH_FUNCS(reg)
172 /* No string on the register */
173 #define fetch_reg_string NULL
174 #define fetch_reg_string_size NULL
175
176 #define DEFINE_FETCH_stack(type) \
177 static __kprobes void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,\
178 void *offset, void *dest) \
179 { \
180 *(type *)dest = (type)regs_get_kernel_stack_nth(regs, \
181 (unsigned int)((unsigned long)offset)); \
182 }
183 DEFINE_BASIC_FETCH_FUNCS(stack)
184 /* No string on the stack entry */
185 #define fetch_stack_string NULL
186 #define fetch_stack_string_size NULL
187
188 #define DEFINE_FETCH_retval(type) \
189 static __kprobes void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs,\
190 void *dummy, void *dest) \
191 { \
192 *(type *)dest = (type)regs_return_value(regs); \
193 }
194 DEFINE_BASIC_FETCH_FUNCS(retval)
195 /* No string on the retval */
196 #define fetch_retval_string NULL
197 #define fetch_retval_string_size NULL
198
199 #define DEFINE_FETCH_memory(type) \
200 static __kprobes void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs,\
201 void *addr, void *dest) \
202 { \
203 type retval; \
204 if (probe_kernel_address(addr, retval)) \
205 *(type *)dest = 0; \
206 else \
207 *(type *)dest = retval; \
208 }
209 DEFINE_BASIC_FETCH_FUNCS(memory)
210 /*
211 * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
212 * length and relative data location.
213 */
214 static __kprobes void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs,
215 void *addr, void *dest)
216 {
217 long ret;
218 int maxlen = get_rloc_len(*(u32 *)dest);
219 u8 *dst = get_rloc_data(dest);
220 u8 *src = addr;
221 mm_segment_t old_fs = get_fs();
222 if (!maxlen)
223 return;
224 /*
225 * Try to get string again, since the string can be changed while
226 * probing.
227 */
228 set_fs(KERNEL_DS);
229 pagefault_disable();
230 do
231 ret = __copy_from_user_inatomic(dst++, src++, 1);
232 while (dst[-1] && ret == 0 && src - (u8 *)addr < maxlen);
233 dst[-1] = '\0';
234 pagefault_enable();
235 set_fs(old_fs);
236
237 if (ret < 0) { /* Failed to fetch string */
238 ((u8 *)get_rloc_data(dest))[0] = '\0';
239 *(u32 *)dest = make_data_rloc(0, get_rloc_offs(*(u32 *)dest));
240 } else
241 *(u32 *)dest = make_data_rloc(src - (u8 *)addr,
242 get_rloc_offs(*(u32 *)dest));
243 }
244 /* Return the length of string -- including null terminal byte */
245 static __kprobes void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs,
246 void *addr, void *dest)
247 {
248 int ret, len = 0;
249 u8 c;
250 mm_segment_t old_fs = get_fs();
251
252 set_fs(KERNEL_DS);
253 pagefault_disable();
254 do {
255 ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1);
256 len++;
257 } while (c && ret == 0 && len < MAX_STRING_SIZE);
258 pagefault_enable();
259 set_fs(old_fs);
260
261 if (ret < 0) /* Failed to check the length */
262 *(u32 *)dest = 0;
263 else
264 *(u32 *)dest = len;
265 }
266
267 /* Memory fetching by symbol */
268 struct symbol_cache {
269 char *symbol;
270 long offset;
271 unsigned long addr;
272 };
273
274 static unsigned long update_symbol_cache(struct symbol_cache *sc)
275 {
276 sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol);
277 if (sc->addr)
278 sc->addr += sc->offset;
279 return sc->addr;
280 }
281
282 static void free_symbol_cache(struct symbol_cache *sc)
283 {
284 kfree(sc->symbol);
285 kfree(sc);
286 }
287
288 static struct symbol_cache *alloc_symbol_cache(const char *sym, long offset)
289 {
290 struct symbol_cache *sc;
291
292 if (!sym || strlen(sym) == 0)
293 return NULL;
294 sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL);
295 if (!sc)
296 return NULL;
297
298 sc->symbol = kstrdup(sym, GFP_KERNEL);
299 if (!sc->symbol) {
300 kfree(sc);
301 return NULL;
302 }
303 sc->offset = offset;
304
305 update_symbol_cache(sc);
306 return sc;
307 }
308
309 #define DEFINE_FETCH_symbol(type) \
310 static __kprobes void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs,\
311 void *data, void *dest) \
312 { \
313 struct symbol_cache *sc = data; \
314 if (sc->addr) \
315 fetch_memory_##type(regs, (void *)sc->addr, dest); \
316 else \
317 *(type *)dest = 0; \
318 }
319 DEFINE_BASIC_FETCH_FUNCS(symbol)
320 DEFINE_FETCH_symbol(string)
321 DEFINE_FETCH_symbol(string_size)
322
323 /* Dereference memory access function */
324 struct deref_fetch_param {
325 struct fetch_param orig;
326 long offset;
327 };
328
329 #define DEFINE_FETCH_deref(type) \
330 static __kprobes void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs,\
331 void *data, void *dest) \
332 { \
333 struct deref_fetch_param *dprm = data; \
334 unsigned long addr; \
335 call_fetch(&dprm->orig, regs, &addr); \
336 if (addr) { \
337 addr += dprm->offset; \
338 fetch_memory_##type(regs, (void *)addr, dest); \
339 } else \
340 *(type *)dest = 0; \
341 }
342 DEFINE_BASIC_FETCH_FUNCS(deref)
343 DEFINE_FETCH_deref(string)
344 DEFINE_FETCH_deref(string_size)
345
346 static __kprobes void update_deref_fetch_param(struct deref_fetch_param *data)
347 {
348 if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
349 update_deref_fetch_param(data->orig.data);
350 else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
351 update_symbol_cache(data->orig.data);
352 }
353
354 static __kprobes void free_deref_fetch_param(struct deref_fetch_param *data)
355 {
356 if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
357 free_deref_fetch_param(data->orig.data);
358 else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
359 free_symbol_cache(data->orig.data);
360 kfree(data);
361 }
362
363 /* Bitfield fetch function */
364 struct bitfield_fetch_param {
365 struct fetch_param orig;
366 unsigned char hi_shift;
367 unsigned char low_shift;
368 };
369
370 #define DEFINE_FETCH_bitfield(type) \
371 static __kprobes void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs,\
372 void *data, void *dest) \
373 { \
374 struct bitfield_fetch_param *bprm = data; \
375 type buf = 0; \
376 call_fetch(&bprm->orig, regs, &buf); \
377 if (buf) { \
378 buf <<= bprm->hi_shift; \
379 buf >>= bprm->low_shift; \
380 } \
381 *(type *)dest = buf; \
382 }
383 DEFINE_BASIC_FETCH_FUNCS(bitfield)
384 #define fetch_bitfield_string NULL
385 #define fetch_bitfield_string_size NULL
386
387 static __kprobes void
388 update_bitfield_fetch_param(struct bitfield_fetch_param *data)
389 {
390 /*
391 * Don't check the bitfield itself, because this must be the
392 * last fetch function.
393 */
394 if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
395 update_deref_fetch_param(data->orig.data);
396 else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
397 update_symbol_cache(data->orig.data);
398 }
399
400 static __kprobes void
401 free_bitfield_fetch_param(struct bitfield_fetch_param *data)
402 {
403 /*
404 * Don't check the bitfield itself, because this must be the
405 * last fetch function.
406 */
407 if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
408 free_deref_fetch_param(data->orig.data);
409 else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
410 free_symbol_cache(data->orig.data);
411 kfree(data);
412 }
413
414 /* Default (unsigned long) fetch type */
415 #define __DEFAULT_FETCH_TYPE(t) u##t
416 #define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t)
417 #define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG)
418 #define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE)
419
420 /* Fetch types */
421 enum {
422 FETCH_MTD_reg = 0,
423 FETCH_MTD_stack,
424 FETCH_MTD_retval,
425 FETCH_MTD_memory,
426 FETCH_MTD_symbol,
427 FETCH_MTD_deref,
428 FETCH_MTD_bitfield,
429 FETCH_MTD_END,
430 };
431
432 #define ASSIGN_FETCH_FUNC(method, type) \
433 [FETCH_MTD_##method] = FETCH_FUNC_NAME(method, type)
434
435 #define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \
436 {.name = _name, \
437 .size = _size, \
438 .is_signed = sign, \
439 .print = PRINT_TYPE_FUNC_NAME(ptype), \
440 .fmt = PRINT_TYPE_FMT_NAME(ptype), \
441 .fmttype = _fmttype, \
442 .fetch = { \
443 ASSIGN_FETCH_FUNC(reg, ftype), \
444 ASSIGN_FETCH_FUNC(stack, ftype), \
445 ASSIGN_FETCH_FUNC(retval, ftype), \
446 ASSIGN_FETCH_FUNC(memory, ftype), \
447 ASSIGN_FETCH_FUNC(symbol, ftype), \
448 ASSIGN_FETCH_FUNC(deref, ftype), \
449 ASSIGN_FETCH_FUNC(bitfield, ftype), \
450 } \
451 }
452
453 #define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \
454 __ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #ptype)
455
456 #define FETCH_TYPE_STRING 0
457 #define FETCH_TYPE_STRSIZE 1
458
459 /* Fetch type information table */
460 static const struct fetch_type {
461 const char *name; /* Name of type */
462 size_t size; /* Byte size of type */
463 int is_signed; /* Signed flag */
464 print_type_func_t print; /* Print functions */
465 const char *fmt; /* Fromat string */
466 const char *fmttype; /* Name in format file */
467 /* Fetch functions */
468 fetch_func_t fetch[FETCH_MTD_END];
469 } fetch_type_table[] = {
470 /* Special types */
471 [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string,
472 sizeof(u32), 1, "__data_loc char[]"),
473 [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32,
474 string_size, sizeof(u32), 0, "u32"),
475 /* Basic types */
476 ASSIGN_FETCH_TYPE(u8, u8, 0),
477 ASSIGN_FETCH_TYPE(u16, u16, 0),
478 ASSIGN_FETCH_TYPE(u32, u32, 0),
479 ASSIGN_FETCH_TYPE(u64, u64, 0),
480 ASSIGN_FETCH_TYPE(s8, u8, 1),
481 ASSIGN_FETCH_TYPE(s16, u16, 1),
482 ASSIGN_FETCH_TYPE(s32, u32, 1),
483 ASSIGN_FETCH_TYPE(s64, u64, 1),
484 };
485
486 static const struct fetch_type *find_fetch_type(const char *type)
487 {
488 int i;
489
490 if (!type)
491 type = DEFAULT_FETCH_TYPE_STR;
492
493 /* Special case: bitfield */
494 if (*type == 'b') {
495 unsigned long bs;
496 type = strchr(type, '/');
497 if (!type)
498 goto fail;
499 type++;
500 if (strict_strtoul(type, 0, &bs))
501 goto fail;
502 switch (bs) {
503 case 8:
504 return find_fetch_type("u8");
505 case 16:
506 return find_fetch_type("u16");
507 case 32:
508 return find_fetch_type("u32");
509 case 64:
510 return find_fetch_type("u64");
511 default:
512 goto fail;
513 }
514 }
515
516 for (i = 0; i < ARRAY_SIZE(fetch_type_table); i++)
517 if (strcmp(type, fetch_type_table[i].name) == 0)
518 return &fetch_type_table[i];
519 fail:
520 return NULL;
521 }
522
523 /* Special function : only accept unsigned long */
524 static __kprobes void fetch_stack_address(struct pt_regs *regs,
525 void *dummy, void *dest)
526 {
527 *(unsigned long *)dest = kernel_stack_pointer(regs);
528 }
529
530 static fetch_func_t get_fetch_size_function(const struct fetch_type *type,
531 fetch_func_t orig_fn)
532 {
533 int i;
534
535 if (type != &fetch_type_table[FETCH_TYPE_STRING])
536 return NULL; /* Only string type needs size function */
537 for (i = 0; i < FETCH_MTD_END; i++)
538 if (type->fetch[i] == orig_fn)
539 return fetch_type_table[FETCH_TYPE_STRSIZE].fetch[i];
540
541 WARN_ON(1); /* This should not happen */
542 return NULL;
543 }
544
545 /**
546 * Kprobe event core functions
547 */
548
549 struct probe_arg {
550 struct fetch_param fetch;
551 struct fetch_param fetch_size;
552 unsigned int offset; /* Offset from argument entry */
553 const char *name; /* Name of this argument */
554 const char *comm; /* Command of this argument */
555 const struct fetch_type *type; /* Type of this argument */
556 };
557
558 /* Flags for trace_probe */
559 #define TP_FLAG_TRACE 1
560 #define TP_FLAG_PROFILE 2
561 #define TP_FLAG_REGISTERED 4
562
563 struct trace_probe {
564 struct list_head list;
565 struct kretprobe rp; /* Use rp.kp for kprobe use */
566 unsigned long nhit;
567 unsigned int flags; /* For TP_FLAG_* */
568 const char *symbol; /* symbol name */
569 struct ftrace_event_class class;
570 struct ftrace_event_call call;
571 ssize_t size; /* trace entry size */
572 unsigned int nr_args;
573 struct probe_arg args[];
574 };
575
576 #define SIZEOF_TRACE_PROBE(n) \
577 (offsetof(struct trace_probe, args) + \
578 (sizeof(struct probe_arg) * (n)))
579
580
581 static __kprobes int trace_probe_is_return(struct trace_probe *tp)
582 {
583 return tp->rp.handler != NULL;
584 }
585
586 static __kprobes const char *trace_probe_symbol(struct trace_probe *tp)
587 {
588 return tp->symbol ? tp->symbol : "unknown";
589 }
590
591 static __kprobes unsigned long trace_probe_offset(struct trace_probe *tp)
592 {
593 return tp->rp.kp.offset;
594 }
595
596 static __kprobes bool trace_probe_is_enabled(struct trace_probe *tp)
597 {
598 return !!(tp->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE));
599 }
600
601 static __kprobes bool trace_probe_is_registered(struct trace_probe *tp)
602 {
603 return !!(tp->flags & TP_FLAG_REGISTERED);
604 }
605
606 static __kprobes bool trace_probe_has_gone(struct trace_probe *tp)
607 {
608 return !!(kprobe_gone(&tp->rp.kp));
609 }
610
611 static __kprobes bool trace_probe_within_module(struct trace_probe *tp,
612 struct module *mod)
613 {
614 int len = strlen(mod->name);
615 const char *name = trace_probe_symbol(tp);
616 return strncmp(mod->name, name, len) == 0 && name[len] == ':';
617 }
618
619 static __kprobes bool trace_probe_is_on_module(struct trace_probe *tp)
620 {
621 return !!strchr(trace_probe_symbol(tp), ':');
622 }
623
624 static int register_probe_event(struct trace_probe *tp);
625 static void unregister_probe_event(struct trace_probe *tp);
626
627 static DEFINE_MUTEX(probe_lock);
628 static LIST_HEAD(probe_list);
629
630 static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs);
631 static int kretprobe_dispatcher(struct kretprobe_instance *ri,
632 struct pt_regs *regs);
633
634 /* Check the name is good for event/group/fields */
635 static int is_good_name(const char *name)
636 {
637 if (!isalpha(*name) && *name != '_')
638 return 0;
639 while (*++name != '\0') {
640 if (!isalpha(*name) && !isdigit(*name) && *name != '_')
641 return 0;
642 }
643 return 1;
644 }
645
646 /*
647 * Allocate new trace_probe and initialize it (including kprobes).
648 */
649 static struct trace_probe *alloc_trace_probe(const char *group,
650 const char *event,
651 void *addr,
652 const char *symbol,
653 unsigned long offs,
654 int nargs, int is_return)
655 {
656 struct trace_probe *tp;
657 int ret = -ENOMEM;
658
659 tp = kzalloc(SIZEOF_TRACE_PROBE(nargs), GFP_KERNEL);
660 if (!tp)
661 return ERR_PTR(ret);
662
663 if (symbol) {
664 tp->symbol = kstrdup(symbol, GFP_KERNEL);
665 if (!tp->symbol)
666 goto error;
667 tp->rp.kp.symbol_name = tp->symbol;
668 tp->rp.kp.offset = offs;
669 } else
670 tp->rp.kp.addr = addr;
671
672 if (is_return)
673 tp->rp.handler = kretprobe_dispatcher;
674 else
675 tp->rp.kp.pre_handler = kprobe_dispatcher;
676
677 if (!event || !is_good_name(event)) {
678 ret = -EINVAL;
679 goto error;
680 }
681
682 tp->call.class = &tp->class;
683 tp->call.name = kstrdup(event, GFP_KERNEL);
684 if (!tp->call.name)
685 goto error;
686
687 if (!group || !is_good_name(group)) {
688 ret = -EINVAL;
689 goto error;
690 }
691
692 tp->class.system = kstrdup(group, GFP_KERNEL);
693 if (!tp->class.system)
694 goto error;
695
696 INIT_LIST_HEAD(&tp->list);
697 return tp;
698 error:
699 kfree(tp->call.name);
700 kfree(tp->symbol);
701 kfree(tp);
702 return ERR_PTR(ret);
703 }
704
705 static void update_probe_arg(struct probe_arg *arg)
706 {
707 if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))
708 update_bitfield_fetch_param(arg->fetch.data);
709 else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
710 update_deref_fetch_param(arg->fetch.data);
711 else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn))
712 update_symbol_cache(arg->fetch.data);
713 }
714
715 static void free_probe_arg(struct probe_arg *arg)
716 {
717 if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))
718 free_bitfield_fetch_param(arg->fetch.data);
719 else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
720 free_deref_fetch_param(arg->fetch.data);
721 else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn))
722 free_symbol_cache(arg->fetch.data);
723 kfree(arg->name);
724 kfree(arg->comm);
725 }
726
727 static void free_trace_probe(struct trace_probe *tp)
728 {
729 int i;
730
731 for (i = 0; i < tp->nr_args; i++)
732 free_probe_arg(&tp->args[i]);
733
734 kfree(tp->call.class->system);
735 kfree(tp->call.name);
736 kfree(tp->symbol);
737 kfree(tp);
738 }
739
740 static struct trace_probe *find_trace_probe(const char *event,
741 const char *group)
742 {
743 struct trace_probe *tp;
744
745 list_for_each_entry(tp, &probe_list, list)
746 if (strcmp(tp->call.name, event) == 0 &&
747 strcmp(tp->call.class->system, group) == 0)
748 return tp;
749 return NULL;
750 }
751
752 /* Enable trace_probe - @flag must be TP_FLAG_TRACE or TP_FLAG_PROFILE */
753 static int enable_trace_probe(struct trace_probe *tp, int flag)
754 {
755 int ret = 0;
756
757 tp->flags |= flag;
758 if (trace_probe_is_enabled(tp) && trace_probe_is_registered(tp) &&
759 !trace_probe_has_gone(tp)) {
760 if (trace_probe_is_return(tp))
761 ret = enable_kretprobe(&tp->rp);
762 else
763 ret = enable_kprobe(&tp->rp.kp);
764 }
765
766 return ret;
767 }
768
769 /* Disable trace_probe - @flag must be TP_FLAG_TRACE or TP_FLAG_PROFILE */
770 static void disable_trace_probe(struct trace_probe *tp, int flag)
771 {
772 tp->flags &= ~flag;
773 if (!trace_probe_is_enabled(tp) && trace_probe_is_registered(tp)) {
774 if (trace_probe_is_return(tp))
775 disable_kretprobe(&tp->rp);
776 else
777 disable_kprobe(&tp->rp.kp);
778 }
779 }
780
781 /* Internal register function - just handle k*probes and flags */
782 static int __register_trace_probe(struct trace_probe *tp)
783 {
784 int i, ret;
785
786 if (trace_probe_is_registered(tp))
787 return -EINVAL;
788
789 for (i = 0; i < tp->nr_args; i++)
790 update_probe_arg(&tp->args[i]);
791
792 /* Set/clear disabled flag according to tp->flag */
793 if (trace_probe_is_enabled(tp))
794 tp->rp.kp.flags &= ~KPROBE_FLAG_DISABLED;
795 else
796 tp->rp.kp.flags |= KPROBE_FLAG_DISABLED;
797
798 if (trace_probe_is_return(tp))
799 ret = register_kretprobe(&tp->rp);
800 else
801 ret = register_kprobe(&tp->rp.kp);
802
803 if (ret == 0)
804 tp->flags |= TP_FLAG_REGISTERED;
805 else {
806 pr_warning("Could not insert probe at %s+%lu: %d\n",
807 trace_probe_symbol(tp), trace_probe_offset(tp), ret);
808 if (ret == -ENOENT && trace_probe_is_on_module(tp)) {
809 pr_warning("This probe might be able to register after"
810 "target module is loaded. Continue.\n");
811 ret = 0;
812 } else if (ret == -EILSEQ) {
813 pr_warning("Probing address(0x%p) is not an "
814 "instruction boundary.\n",
815 tp->rp.kp.addr);
816 ret = -EINVAL;
817 }
818 }
819
820 return ret;
821 }
822
823 /* Internal unregister function - just handle k*probes and flags */
824 static void __unregister_trace_probe(struct trace_probe *tp)
825 {
826 if (trace_probe_is_registered(tp)) {
827 if (trace_probe_is_return(tp))
828 unregister_kretprobe(&tp->rp);
829 else
830 unregister_kprobe(&tp->rp.kp);
831 tp->flags &= ~TP_FLAG_REGISTERED;
832 /* Cleanup kprobe for reuse */
833 if (tp->rp.kp.symbol_name)
834 tp->rp.kp.addr = NULL;
835 }
836 }
837
838 /* Unregister a trace_probe and probe_event: call with locking probe_lock */
839 static void unregister_trace_probe(struct trace_probe *tp)
840 {
841 __unregister_trace_probe(tp);
842 list_del(&tp->list);
843 unregister_probe_event(tp);
844 }
845
846 /* Register a trace_probe and probe_event */
847 static int register_trace_probe(struct trace_probe *tp)
848 {
849 struct trace_probe *old_tp;
850 int ret;
851
852 mutex_lock(&probe_lock);
853
854 /* Delete old (same name) event if exist */
855 old_tp = find_trace_probe(tp->call.name, tp->call.class->system);
856 if (old_tp) {
857 unregister_trace_probe(old_tp);
858 free_trace_probe(old_tp);
859 }
860
861 /* Register new event */
862 ret = register_probe_event(tp);
863 if (ret) {
864 pr_warning("Failed to register probe event(%d)\n", ret);
865 goto end;
866 }
867
868 /* Register k*probe */
869 ret = __register_trace_probe(tp);
870 if (ret < 0)
871 unregister_probe_event(tp);
872 else
873 list_add_tail(&tp->list, &probe_list);
874
875 end:
876 mutex_unlock(&probe_lock);
877 return ret;
878 }
879
880 /* Module notifier call back, checking event on the module */
881 static int trace_probe_module_callback(struct notifier_block *nb,
882 unsigned long val, void *data)
883 {
884 struct module *mod = data;
885 struct trace_probe *tp;
886 int ret;
887
888 if (val != MODULE_STATE_COMING)
889 return NOTIFY_DONE;
890
891 /* Update probes on coming module */
892 mutex_lock(&probe_lock);
893 list_for_each_entry(tp, &probe_list, list) {
894 if (trace_probe_within_module(tp, mod)) {
895 __unregister_trace_probe(tp);
896 ret = __register_trace_probe(tp);
897 if (ret)
898 pr_warning("Failed to re-register probe %s on"
899 "%s: %d\n",
900 tp->call.name, mod->name, ret);
901 }
902 }
903 mutex_unlock(&probe_lock);
904
905 return NOTIFY_DONE;
906 }
907
908 static struct notifier_block trace_probe_module_nb = {
909 .notifier_call = trace_probe_module_callback,
910 .priority = 1 /* Invoked after kprobe module callback */
911 };
912
913 /* Split symbol and offset. */
914 static int split_symbol_offset(char *symbol, unsigned long *offset)
915 {
916 char *tmp;
917 int ret;
918
919 if (!offset)
920 return -EINVAL;
921
922 tmp = strchr(symbol, '+');
923 if (tmp) {
924 /* skip sign because strict_strtol doesn't accept '+' */
925 ret = strict_strtoul(tmp + 1, 0, offset);
926 if (ret)
927 return ret;
928 *tmp = '\0';
929 } else
930 *offset = 0;
931 return 0;
932 }
933
934 #define PARAM_MAX_ARGS 16
935 #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
936
937 static int parse_probe_vars(char *arg, const struct fetch_type *t,
938 struct fetch_param *f, int is_return)
939 {
940 int ret = 0;
941 unsigned long param;
942
943 if (strcmp(arg, "retval") == 0) {
944 if (is_return)
945 f->fn = t->fetch[FETCH_MTD_retval];
946 else
947 ret = -EINVAL;
948 } else if (strncmp(arg, "stack", 5) == 0) {
949 if (arg[5] == '\0') {
950 if (strcmp(t->name, DEFAULT_FETCH_TYPE_STR) == 0)
951 f->fn = fetch_stack_address;
952 else
953 ret = -EINVAL;
954 } else if (isdigit(arg[5])) {
955 ret = strict_strtoul(arg + 5, 10, &param);
956 if (ret || param > PARAM_MAX_STACK)
957 ret = -EINVAL;
958 else {
959 f->fn = t->fetch[FETCH_MTD_stack];
960 f->data = (void *)param;
961 }
962 } else
963 ret = -EINVAL;
964 } else
965 ret = -EINVAL;
966 return ret;
967 }
968
969 /* Recursive argument parser */
970 static int __parse_probe_arg(char *arg, const struct fetch_type *t,
971 struct fetch_param *f, int is_return)
972 {
973 int ret = 0;
974 unsigned long param;
975 long offset;
976 char *tmp;
977
978 switch (arg[0]) {
979 case '$':
980 ret = parse_probe_vars(arg + 1, t, f, is_return);
981 break;
982 case '%': /* named register */
983 ret = regs_query_register_offset(arg + 1);
984 if (ret >= 0) {
985 f->fn = t->fetch[FETCH_MTD_reg];
986 f->data = (void *)(unsigned long)ret;
987 ret = 0;
988 }
989 break;
990 case '@': /* memory or symbol */
991 if (isdigit(arg[1])) {
992 ret = strict_strtoul(arg + 1, 0, &param);
993 if (ret)
994 break;
995 f->fn = t->fetch[FETCH_MTD_memory];
996 f->data = (void *)param;
997 } else {
998 ret = split_symbol_offset(arg + 1, &offset);
999 if (ret)
1000 break;
1001 f->data = alloc_symbol_cache(arg + 1, offset);
1002 if (f->data)
1003 f->fn = t->fetch[FETCH_MTD_symbol];
1004 }
1005 break;
1006 case '+': /* deref memory */
1007 arg++; /* Skip '+', because strict_strtol() rejects it. */
1008 case '-':
1009 tmp = strchr(arg, '(');
1010 if (!tmp)
1011 break;
1012 *tmp = '\0';
1013 ret = strict_strtol(arg, 0, &offset);
1014 if (ret)
1015 break;
1016 arg = tmp + 1;
1017 tmp = strrchr(arg, ')');
1018 if (tmp) {
1019 struct deref_fetch_param *dprm;
1020 const struct fetch_type *t2 = find_fetch_type(NULL);
1021 *tmp = '\0';
1022 dprm = kzalloc(sizeof(struct deref_fetch_param),
1023 GFP_KERNEL);
1024 if (!dprm)
1025 return -ENOMEM;
1026 dprm->offset = offset;
1027 ret = __parse_probe_arg(arg, t2, &dprm->orig,
1028 is_return);
1029 if (ret)
1030 kfree(dprm);
1031 else {
1032 f->fn = t->fetch[FETCH_MTD_deref];
1033 f->data = (void *)dprm;
1034 }
1035 }
1036 break;
1037 }
1038 if (!ret && !f->fn) { /* Parsed, but do not find fetch method */
1039 pr_info("%s type has no corresponding fetch method.\n",
1040 t->name);
1041 ret = -EINVAL;
1042 }
1043 return ret;
1044 }
1045
1046 #define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long))
1047
1048 /* Bitfield type needs to be parsed into a fetch function */
1049 static int __parse_bitfield_probe_arg(const char *bf,
1050 const struct fetch_type *t,
1051 struct fetch_param *f)
1052 {
1053 struct bitfield_fetch_param *bprm;
1054 unsigned long bw, bo;
1055 char *tail;
1056
1057 if (*bf != 'b')
1058 return 0;
1059
1060 bprm = kzalloc(sizeof(*bprm), GFP_KERNEL);
1061 if (!bprm)
1062 return -ENOMEM;
1063 bprm->orig = *f;
1064 f->fn = t->fetch[FETCH_MTD_bitfield];
1065 f->data = (void *)bprm;
1066
1067 bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */
1068 if (bw == 0 || *tail != '@')
1069 return -EINVAL;
1070
1071 bf = tail + 1;
1072 bo = simple_strtoul(bf, &tail, 0);
1073 if (tail == bf || *tail != '/')
1074 return -EINVAL;
1075
1076 bprm->hi_shift = BYTES_TO_BITS(t->size) - (bw + bo);
1077 bprm->low_shift = bprm->hi_shift + bo;
1078 return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0;
1079 }
1080
1081 /* String length checking wrapper */
1082 static int parse_probe_arg(char *arg, struct trace_probe *tp,
1083 struct probe_arg *parg, int is_return)
1084 {
1085 const char *t;
1086 int ret;
1087
1088 if (strlen(arg) > MAX_ARGSTR_LEN) {
1089 pr_info("Argument is too long.: %s\n", arg);
1090 return -ENOSPC;
1091 }
1092 parg->comm = kstrdup(arg, GFP_KERNEL);
1093 if (!parg->comm) {
1094 pr_info("Failed to allocate memory for command '%s'.\n", arg);
1095 return -ENOMEM;
1096 }
1097 t = strchr(parg->comm, ':');
1098 if (t) {
1099 arg[t - parg->comm] = '\0';
1100 t++;
1101 }
1102 parg->type = find_fetch_type(t);
1103 if (!parg->type) {
1104 pr_info("Unsupported type: %s\n", t);
1105 return -EINVAL;
1106 }
1107 parg->offset = tp->size;
1108 tp->size += parg->type->size;
1109 ret = __parse_probe_arg(arg, parg->type, &parg->fetch, is_return);
1110 if (ret >= 0 && t != NULL)
1111 ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch);
1112 if (ret >= 0) {
1113 parg->fetch_size.fn = get_fetch_size_function(parg->type,
1114 parg->fetch.fn);
1115 parg->fetch_size.data = parg->fetch.data;
1116 }
1117 return ret;
1118 }
1119
1120 /* Return 1 if name is reserved or already used by another argument */
1121 static int conflict_field_name(const char *name,
1122 struct probe_arg *args, int narg)
1123 {
1124 int i;
1125 for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++)
1126 if (strcmp(reserved_field_names[i], name) == 0)
1127 return 1;
1128 for (i = 0; i < narg; i++)
1129 if (strcmp(args[i].name, name) == 0)
1130 return 1;
1131 return 0;
1132 }
1133
1134 static int create_trace_probe(int argc, char **argv)
1135 {
1136 /*
1137 * Argument syntax:
1138 * - Add kprobe: p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS]
1139 * - Add kretprobe: r[:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS]
1140 * Fetch args:
1141 * $retval : fetch return value
1142 * $stack : fetch stack address
1143 * $stackN : fetch Nth of stack (N:0-)
1144 * @ADDR : fetch memory at ADDR (ADDR should be in kernel)
1145 * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol)
1146 * %REG : fetch register REG
1147 * Dereferencing memory fetch:
1148 * +|-offs(ARG) : fetch memory at ARG +|- offs address.
1149 * Alias name of args:
1150 * NAME=FETCHARG : set NAME as alias of FETCHARG.
1151 * Type of args:
1152 * FETCHARG:TYPE : use TYPE instead of unsigned long.
1153 */
1154 struct trace_probe *tp;
1155 int i, ret = 0;
1156 int is_return = 0, is_delete = 0;
1157 char *symbol = NULL, *event = NULL, *group = NULL;
1158 char *arg;
1159 unsigned long offset = 0;
1160 void *addr = NULL;
1161 char buf[MAX_EVENT_NAME_LEN];
1162
1163 /* argc must be >= 1 */
1164 if (argv[0][0] == 'p')
1165 is_return = 0;
1166 else if (argv[0][0] == 'r')
1167 is_return = 1;
1168 else if (argv[0][0] == '-')
1169 is_delete = 1;
1170 else {
1171 pr_info("Probe definition must be started with 'p', 'r' or"
1172 " '-'.\n");
1173 return -EINVAL;
1174 }
1175
1176 if (argv[0][1] == ':') {
1177 event = &argv[0][2];
1178 if (strchr(event, '/')) {
1179 group = event;
1180 event = strchr(group, '/') + 1;
1181 event[-1] = '\0';
1182 if (strlen(group) == 0) {
1183 pr_info("Group name is not specified\n");
1184 return -EINVAL;
1185 }
1186 }
1187 if (strlen(event) == 0) {
1188 pr_info("Event name is not specified\n");
1189 return -EINVAL;
1190 }
1191 }
1192 if (!group)
1193 group = KPROBE_EVENT_SYSTEM;
1194
1195 if (is_delete) {
1196 if (!event) {
1197 pr_info("Delete command needs an event name.\n");
1198 return -EINVAL;
1199 }
1200 mutex_lock(&probe_lock);
1201 tp = find_trace_probe(event, group);
1202 if (!tp) {
1203 mutex_unlock(&probe_lock);
1204 pr_info("Event %s/%s doesn't exist.\n", group, event);
1205 return -ENOENT;
1206 }
1207 /* delete an event */
1208 unregister_trace_probe(tp);
1209 free_trace_probe(tp);
1210 mutex_unlock(&probe_lock);
1211 return 0;
1212 }
1213
1214 if (argc < 2) {
1215 pr_info("Probe point is not specified.\n");
1216 return -EINVAL;
1217 }
1218 if (isdigit(argv[1][0])) {
1219 if (is_return) {
1220 pr_info("Return probe point must be a symbol.\n");
1221 return -EINVAL;
1222 }
1223 /* an address specified */
1224 ret = strict_strtoul(&argv[1][0], 0, (unsigned long *)&addr);
1225 if (ret) {
1226 pr_info("Failed to parse address.\n");
1227 return ret;
1228 }
1229 } else {
1230 /* a symbol specified */
1231 symbol = argv[1];
1232 /* TODO: support .init module functions */
1233 ret = split_symbol_offset(symbol, &offset);
1234 if (ret) {
1235 pr_info("Failed to parse symbol.\n");
1236 return ret;
1237 }
1238 if (offset && is_return) {
1239 pr_info("Return probe must be used without offset.\n");
1240 return -EINVAL;
1241 }
1242 }
1243 argc -= 2; argv += 2;
1244
1245 /* setup a probe */
1246 if (!event) {
1247 /* Make a new event name */
1248 if (symbol)
1249 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld",
1250 is_return ? 'r' : 'p', symbol, offset);
1251 else
1252 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p",
1253 is_return ? 'r' : 'p', addr);
1254 event = buf;
1255 }
1256 tp = alloc_trace_probe(group, event, addr, symbol, offset, argc,
1257 is_return);
1258 if (IS_ERR(tp)) {
1259 pr_info("Failed to allocate trace_probe.(%d)\n",
1260 (int)PTR_ERR(tp));
1261 return PTR_ERR(tp);
1262 }
1263
1264 /* parse arguments */
1265 ret = 0;
1266 for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
1267 /* Increment count for freeing args in error case */
1268 tp->nr_args++;
1269
1270 /* Parse argument name */
1271 arg = strchr(argv[i], '=');
1272 if (arg) {
1273 *arg++ = '\0';
1274 tp->args[i].name = kstrdup(argv[i], GFP_KERNEL);
1275 } else {
1276 arg = argv[i];
1277 /* If argument name is omitted, set "argN" */
1278 snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1);
1279 tp->args[i].name = kstrdup(buf, GFP_KERNEL);
1280 }
1281
1282 if (!tp->args[i].name) {
1283 pr_info("Failed to allocate argument[%d] name.\n", i);
1284 ret = -ENOMEM;
1285 goto error;
1286 }
1287
1288 if (!is_good_name(tp->args[i].name)) {
1289 pr_info("Invalid argument[%d] name: %s\n",
1290 i, tp->args[i].name);
1291 ret = -EINVAL;
1292 goto error;
1293 }
1294
1295 if (conflict_field_name(tp->args[i].name, tp->args, i)) {
1296 pr_info("Argument[%d] name '%s' conflicts with "
1297 "another field.\n", i, argv[i]);
1298 ret = -EINVAL;
1299 goto error;
1300 }
1301
1302 /* Parse fetch argument */
1303 ret = parse_probe_arg(arg, tp, &tp->args[i], is_return);
1304 if (ret) {
1305 pr_info("Parse error at argument[%d]. (%d)\n", i, ret);
1306 goto error;
1307 }
1308 }
1309
1310 ret = register_trace_probe(tp);
1311 if (ret)
1312 goto error;
1313 return 0;
1314
1315 error:
1316 free_trace_probe(tp);
1317 return ret;
1318 }
1319
1320 static void release_all_trace_probes(void)
1321 {
1322 struct trace_probe *tp;
1323
1324 mutex_lock(&probe_lock);
1325 /* TODO: Use batch unregistration */
1326 while (!list_empty(&probe_list)) {
1327 tp = list_entry(probe_list.next, struct trace_probe, list);
1328 unregister_trace_probe(tp);
1329 free_trace_probe(tp);
1330 }
1331 mutex_unlock(&probe_lock);
1332 }
1333
1334 /* Probes listing interfaces */
1335 static void *probes_seq_start(struct seq_file *m, loff_t *pos)
1336 {
1337 mutex_lock(&probe_lock);
1338 return seq_list_start(&probe_list, *pos);
1339 }
1340
1341 static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos)
1342 {
1343 return seq_list_next(v, &probe_list, pos);
1344 }
1345
1346 static void probes_seq_stop(struct seq_file *m, void *v)
1347 {
1348 mutex_unlock(&probe_lock);
1349 }
1350
1351 static int probes_seq_show(struct seq_file *m, void *v)
1352 {
1353 struct trace_probe *tp = v;
1354 int i;
1355
1356 seq_printf(m, "%c", trace_probe_is_return(tp) ? 'r' : 'p');
1357 seq_printf(m, ":%s/%s", tp->call.class->system, tp->call.name);
1358
1359 if (!tp->symbol)
1360 seq_printf(m, " 0x%p", tp->rp.kp.addr);
1361 else if (tp->rp.kp.offset)
1362 seq_printf(m, " %s+%u", trace_probe_symbol(tp),
1363 tp->rp.kp.offset);
1364 else
1365 seq_printf(m, " %s", trace_probe_symbol(tp));
1366
1367 for (i = 0; i < tp->nr_args; i++)
1368 seq_printf(m, " %s=%s", tp->args[i].name, tp->args[i].comm);
1369 seq_printf(m, "\n");
1370
1371 return 0;
1372 }
1373
1374 static const struct seq_operations probes_seq_op = {
1375 .start = probes_seq_start,
1376 .next = probes_seq_next,
1377 .stop = probes_seq_stop,
1378 .show = probes_seq_show
1379 };
1380
1381 static int probes_open(struct inode *inode, struct file *file)
1382 {
1383 if ((file->f_mode & FMODE_WRITE) &&
1384 (file->f_flags & O_TRUNC))
1385 release_all_trace_probes();
1386
1387 return seq_open(file, &probes_seq_op);
1388 }
1389
1390 static int command_trace_probe(const char *buf)
1391 {
1392 char **argv;
1393 int argc = 0, ret = 0;
1394
1395 argv = argv_split(GFP_KERNEL, buf, &argc);
1396 if (!argv)
1397 return -ENOMEM;
1398
1399 if (argc)
1400 ret = create_trace_probe(argc, argv);
1401
1402 argv_free(argv);
1403 return ret;
1404 }
1405
1406 #define WRITE_BUFSIZE 4096
1407
1408 static ssize_t probes_write(struct file *file, const char __user *buffer,
1409 size_t count, loff_t *ppos)
1410 {
1411 char *kbuf, *tmp;
1412 int ret;
1413 size_t done;
1414 size_t size;
1415
1416 kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL);
1417 if (!kbuf)
1418 return -ENOMEM;
1419
1420 ret = done = 0;
1421 while (done < count) {
1422 size = count - done;
1423 if (size >= WRITE_BUFSIZE)
1424 size = WRITE_BUFSIZE - 1;
1425 if (copy_from_user(kbuf, buffer + done, size)) {
1426 ret = -EFAULT;
1427 goto out;
1428 }
1429 kbuf[size] = '\0';
1430 tmp = strchr(kbuf, '\n');
1431 if (tmp) {
1432 *tmp = '\0';
1433 size = tmp - kbuf + 1;
1434 } else if (done + size < count) {
1435 pr_warning("Line length is too long: "
1436 "Should be less than %d.", WRITE_BUFSIZE);
1437 ret = -EINVAL;
1438 goto out;
1439 }
1440 done += size;
1441 /* Remove comments */
1442 tmp = strchr(kbuf, '#');
1443 if (tmp)
1444 *tmp = '\0';
1445
1446 ret = command_trace_probe(kbuf);
1447 if (ret)
1448 goto out;
1449 }
1450 ret = done;
1451 out:
1452 kfree(kbuf);
1453 return ret;
1454 }
1455
1456 static const struct file_operations kprobe_events_ops = {
1457 .owner = THIS_MODULE,
1458 .open = probes_open,
1459 .read = seq_read,
1460 .llseek = seq_lseek,
1461 .release = seq_release,
1462 .write = probes_write,
1463 };
1464
1465 /* Probes profiling interfaces */
1466 static int probes_profile_seq_show(struct seq_file *m, void *v)
1467 {
1468 struct trace_probe *tp = v;
1469
1470 seq_printf(m, " %-44s %15lu %15lu\n", tp->call.name, tp->nhit,
1471 tp->rp.kp.nmissed);
1472
1473 return 0;
1474 }
1475
1476 static const struct seq_operations profile_seq_op = {
1477 .start = probes_seq_start,
1478 .next = probes_seq_next,
1479 .stop = probes_seq_stop,
1480 .show = probes_profile_seq_show
1481 };
1482
1483 static int profile_open(struct inode *inode, struct file *file)
1484 {
1485 return seq_open(file, &profile_seq_op);
1486 }
1487
1488 static const struct file_operations kprobe_profile_ops = {
1489 .owner = THIS_MODULE,
1490 .open = profile_open,
1491 .read = seq_read,
1492 .llseek = seq_lseek,
1493 .release = seq_release,
1494 };
1495
1496 /* Sum up total data length for dynamic arraies (strings) */
1497 static __kprobes int __get_data_size(struct trace_probe *tp,
1498 struct pt_regs *regs)
1499 {
1500 int i, ret = 0;
1501 u32 len;
1502
1503 for (i = 0; i < tp->nr_args; i++)
1504 if (unlikely(tp->args[i].fetch_size.fn)) {
1505 call_fetch(&tp->args[i].fetch_size, regs, &len);
1506 ret += len;
1507 }
1508
1509 return ret;
1510 }
1511
1512 /* Store the value of each argument */
1513 static __kprobes void store_trace_args(int ent_size, struct trace_probe *tp,
1514 struct pt_regs *regs,
1515 u8 *data, int maxlen)
1516 {
1517 int i;
1518 u32 end = tp->size;
1519 u32 *dl; /* Data (relative) location */
1520
1521 for (i = 0; i < tp->nr_args; i++) {
1522 if (unlikely(tp->args[i].fetch_size.fn)) {
1523 /*
1524 * First, we set the relative location and
1525 * maximum data length to *dl
1526 */
1527 dl = (u32 *)(data + tp->args[i].offset);
1528 *dl = make_data_rloc(maxlen, end - tp->args[i].offset);
1529 /* Then try to fetch string or dynamic array data */
1530 call_fetch(&tp->args[i].fetch, regs, dl);
1531 /* Reduce maximum length */
1532 end += get_rloc_len(*dl);
1533 maxlen -= get_rloc_len(*dl);
1534 /* Trick here, convert data_rloc to data_loc */
1535 *dl = convert_rloc_to_loc(*dl,
1536 ent_size + tp->args[i].offset);
1537 } else
1538 /* Just fetching data normally */
1539 call_fetch(&tp->args[i].fetch, regs,
1540 data + tp->args[i].offset);
1541 }
1542 }
1543
1544 /* Kprobe handler */
1545 static __kprobes void kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs)
1546 {
1547 struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
1548 struct kprobe_trace_entry_head *entry;
1549 struct ring_buffer_event *event;
1550 struct ring_buffer *buffer;
1551 int size, dsize, pc;
1552 unsigned long irq_flags;
1553 struct ftrace_event_call *call = &tp->call;
1554
1555 tp->nhit++;
1556
1557 local_save_flags(irq_flags);
1558 pc = preempt_count();
1559
1560 dsize = __get_data_size(tp, regs);
1561 size = sizeof(*entry) + tp->size + dsize;
1562
1563 event = trace_current_buffer_lock_reserve(&buffer, call->event.type,
1564 size, irq_flags, pc);
1565 if (!event)
1566 return;
1567
1568 entry = ring_buffer_event_data(event);
1569 entry->ip = (unsigned long)kp->addr;
1570 store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize);
1571
1572 if (!filter_current_check_discard(buffer, call, entry, event))
1573 trace_nowake_buffer_unlock_commit_regs(buffer, event,
1574 irq_flags, pc, regs);
1575 }
1576
1577 /* Kretprobe handler */
1578 static __kprobes void kretprobe_trace_func(struct kretprobe_instance *ri,
1579 struct pt_regs *regs)
1580 {
1581 struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
1582 struct kretprobe_trace_entry_head *entry;
1583 struct ring_buffer_event *event;
1584 struct ring_buffer *buffer;
1585 int size, pc, dsize;
1586 unsigned long irq_flags;
1587 struct ftrace_event_call *call = &tp->call;
1588
1589 local_save_flags(irq_flags);
1590 pc = preempt_count();
1591
1592 dsize = __get_data_size(tp, regs);
1593 size = sizeof(*entry) + tp->size + dsize;
1594
1595 event = trace_current_buffer_lock_reserve(&buffer, call->event.type,
1596 size, irq_flags, pc);
1597 if (!event)
1598 return;
1599
1600 entry = ring_buffer_event_data(event);
1601 entry->func = (unsigned long)tp->rp.kp.addr;
1602 entry->ret_ip = (unsigned long)ri->ret_addr;
1603 store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize);
1604
1605 if (!filter_current_check_discard(buffer, call, entry, event))
1606 trace_nowake_buffer_unlock_commit_regs(buffer, event,
1607 irq_flags, pc, regs);
1608 }
1609
1610 /* Event entry printers */
1611 enum print_line_t
1612 print_kprobe_event(struct trace_iterator *iter, int flags,
1613 struct trace_event *event)
1614 {
1615 struct kprobe_trace_entry_head *field;
1616 struct trace_seq *s = &iter->seq;
1617 struct trace_probe *tp;
1618 u8 *data;
1619 int i;
1620
1621 field = (struct kprobe_trace_entry_head *)iter->ent;
1622 tp = container_of(event, struct trace_probe, call.event);
1623
1624 if (!trace_seq_printf(s, "%s: (", tp->call.name))
1625 goto partial;
1626
1627 if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET))
1628 goto partial;
1629
1630 if (!trace_seq_puts(s, ")"))
1631 goto partial;
1632
1633 data = (u8 *)&field[1];
1634 for (i = 0; i < tp->nr_args; i++)
1635 if (!tp->args[i].type->print(s, tp->args[i].name,
1636 data + tp->args[i].offset, field))
1637 goto partial;
1638
1639 if (!trace_seq_puts(s, "\n"))
1640 goto partial;
1641
1642 return TRACE_TYPE_HANDLED;
1643 partial:
1644 return TRACE_TYPE_PARTIAL_LINE;
1645 }
1646
1647 enum print_line_t
1648 print_kretprobe_event(struct trace_iterator *iter, int flags,
1649 struct trace_event *event)
1650 {
1651 struct kretprobe_trace_entry_head *field;
1652 struct trace_seq *s = &iter->seq;
1653 struct trace_probe *tp;
1654 u8 *data;
1655 int i;
1656
1657 field = (struct kretprobe_trace_entry_head *)iter->ent;
1658 tp = container_of(event, struct trace_probe, call.event);
1659
1660 if (!trace_seq_printf(s, "%s: (", tp->call.name))
1661 goto partial;
1662
1663 if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET))
1664 goto partial;
1665
1666 if (!trace_seq_puts(s, " <- "))
1667 goto partial;
1668
1669 if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET))
1670 goto partial;
1671
1672 if (!trace_seq_puts(s, ")"))
1673 goto partial;
1674
1675 data = (u8 *)&field[1];
1676 for (i = 0; i < tp->nr_args; i++)
1677 if (!tp->args[i].type->print(s, tp->args[i].name,
1678 data + tp->args[i].offset, field))
1679 goto partial;
1680
1681 if (!trace_seq_puts(s, "\n"))
1682 goto partial;
1683
1684 return TRACE_TYPE_HANDLED;
1685 partial:
1686 return TRACE_TYPE_PARTIAL_LINE;
1687 }
1688
1689 #undef DEFINE_FIELD
1690 #define DEFINE_FIELD(type, item, name, is_signed) \
1691 do { \
1692 ret = trace_define_field(event_call, #type, name, \
1693 offsetof(typeof(field), item), \
1694 sizeof(field.item), is_signed, \
1695 FILTER_OTHER); \
1696 if (ret) \
1697 return ret; \
1698 } while (0)
1699
1700 static int kprobe_event_define_fields(struct ftrace_event_call *event_call)
1701 {
1702 int ret, i;
1703 struct kprobe_trace_entry_head field;
1704 struct trace_probe *tp = (struct trace_probe *)event_call->data;
1705
1706 DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0);
1707 /* Set argument names as fields */
1708 for (i = 0; i < tp->nr_args; i++) {
1709 ret = trace_define_field(event_call, tp->args[i].type->fmttype,
1710 tp->args[i].name,
1711 sizeof(field) + tp->args[i].offset,
1712 tp->args[i].type->size,
1713 tp->args[i].type->is_signed,
1714 FILTER_OTHER);
1715 if (ret)
1716 return ret;
1717 }
1718 return 0;
1719 }
1720
1721 static int kretprobe_event_define_fields(struct ftrace_event_call *event_call)
1722 {
1723 int ret, i;
1724 struct kretprobe_trace_entry_head field;
1725 struct trace_probe *tp = (struct trace_probe *)event_call->data;
1726
1727 DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0);
1728 DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0);
1729 /* Set argument names as fields */
1730 for (i = 0; i < tp->nr_args; i++) {
1731 ret = trace_define_field(event_call, tp->args[i].type->fmttype,
1732 tp->args[i].name,
1733 sizeof(field) + tp->args[i].offset,
1734 tp->args[i].type->size,
1735 tp->args[i].type->is_signed,
1736 FILTER_OTHER);
1737 if (ret)
1738 return ret;
1739 }
1740 return 0;
1741 }
1742
1743 static int __set_print_fmt(struct trace_probe *tp, char *buf, int len)
1744 {
1745 int i;
1746 int pos = 0;
1747
1748 const char *fmt, *arg;
1749
1750 if (!trace_probe_is_return(tp)) {
1751 fmt = "(%lx)";
1752 arg = "REC->" FIELD_STRING_IP;
1753 } else {
1754 fmt = "(%lx <- %lx)";
1755 arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP;
1756 }
1757
1758 /* When len=0, we just calculate the needed length */
1759 #define LEN_OR_ZERO (len ? len - pos : 0)
1760
1761 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt);
1762
1763 for (i = 0; i < tp->nr_args; i++) {
1764 pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%s",
1765 tp->args[i].name, tp->args[i].type->fmt);
1766 }
1767
1768 pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg);
1769
1770 for (i = 0; i < tp->nr_args; i++) {
1771 if (strcmp(tp->args[i].type->name, "string") == 0)
1772 pos += snprintf(buf + pos, LEN_OR_ZERO,
1773 ", __get_str(%s)",
1774 tp->args[i].name);
1775 else
1776 pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s",
1777 tp->args[i].name);
1778 }
1779
1780 #undef LEN_OR_ZERO
1781
1782 /* return the length of print_fmt */
1783 return pos;
1784 }
1785
1786 static int set_print_fmt(struct trace_probe *tp)
1787 {
1788 int len;
1789 char *print_fmt;
1790
1791 /* First: called with 0 length to calculate the needed length */
1792 len = __set_print_fmt(tp, NULL, 0);
1793 print_fmt = kmalloc(len + 1, GFP_KERNEL);
1794 if (!print_fmt)
1795 return -ENOMEM;
1796
1797 /* Second: actually write the @print_fmt */
1798 __set_print_fmt(tp, print_fmt, len + 1);
1799 tp->call.print_fmt = print_fmt;
1800
1801 return 0;
1802 }
1803
1804 #ifdef CONFIG_PERF_EVENTS
1805
1806 /* Kprobe profile handler */
1807 static __kprobes void kprobe_perf_func(struct kprobe *kp,
1808 struct pt_regs *regs)
1809 {
1810 struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
1811 struct ftrace_event_call *call = &tp->call;
1812 struct kprobe_trace_entry_head *entry;
1813 struct hlist_head *head;
1814 int size, __size, dsize;
1815 int rctx;
1816
1817 dsize = __get_data_size(tp, regs);
1818 __size = sizeof(*entry) + tp->size + dsize;
1819 size = ALIGN(__size + sizeof(u32), sizeof(u64));
1820 size -= sizeof(u32);
1821 if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
1822 "profile buffer not large enough"))
1823 return;
1824
1825 entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx);
1826 if (!entry)
1827 return;
1828
1829 entry->ip = (unsigned long)kp->addr;
1830 memset(&entry[1], 0, dsize);
1831 store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize);
1832
1833 head = this_cpu_ptr(call->perf_events);
1834 perf_trace_buf_submit(entry, size, rctx, entry->ip, 1, regs, head);
1835 }
1836
1837 /* Kretprobe profile handler */
1838 static __kprobes void kretprobe_perf_func(struct kretprobe_instance *ri,
1839 struct pt_regs *regs)
1840 {
1841 struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
1842 struct ftrace_event_call *call = &tp->call;
1843 struct kretprobe_trace_entry_head *entry;
1844 struct hlist_head *head;
1845 int size, __size, dsize;
1846 int rctx;
1847
1848 dsize = __get_data_size(tp, regs);
1849 __size = sizeof(*entry) + tp->size + dsize;
1850 size = ALIGN(__size + sizeof(u32), sizeof(u64));
1851 size -= sizeof(u32);
1852 if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
1853 "profile buffer not large enough"))
1854 return;
1855
1856 entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx);
1857 if (!entry)
1858 return;
1859
1860 entry->func = (unsigned long)tp->rp.kp.addr;
1861 entry->ret_ip = (unsigned long)ri->ret_addr;
1862 store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize);
1863
1864 head = this_cpu_ptr(call->perf_events);
1865 perf_trace_buf_submit(entry, size, rctx, entry->ret_ip, 1, regs, head);
1866 }
1867 #endif /* CONFIG_PERF_EVENTS */
1868
1869 static __kprobes
1870 int kprobe_register(struct ftrace_event_call *event, enum trace_reg type)
1871 {
1872 struct trace_probe *tp = (struct trace_probe *)event->data;
1873
1874 switch (type) {
1875 case TRACE_REG_REGISTER:
1876 return enable_trace_probe(tp, TP_FLAG_TRACE);
1877 case TRACE_REG_UNREGISTER:
1878 disable_trace_probe(tp, TP_FLAG_TRACE);
1879 return 0;
1880
1881 #ifdef CONFIG_PERF_EVENTS
1882 case TRACE_REG_PERF_REGISTER:
1883 return enable_trace_probe(tp, TP_FLAG_PROFILE);
1884 case TRACE_REG_PERF_UNREGISTER:
1885 disable_trace_probe(tp, TP_FLAG_PROFILE);
1886 return 0;
1887 #endif
1888 }
1889 return 0;
1890 }
1891
1892 static __kprobes
1893 int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs)
1894 {
1895 struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
1896
1897 if (tp->flags & TP_FLAG_TRACE)
1898 kprobe_trace_func(kp, regs);
1899 #ifdef CONFIG_PERF_EVENTS
1900 if (tp->flags & TP_FLAG_PROFILE)
1901 kprobe_perf_func(kp, regs);
1902 #endif
1903 return 0; /* We don't tweek kernel, so just return 0 */
1904 }
1905
1906 static __kprobes
1907 int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs)
1908 {
1909 struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
1910
1911 if (tp->flags & TP_FLAG_TRACE)
1912 kretprobe_trace_func(ri, regs);
1913 #ifdef CONFIG_PERF_EVENTS
1914 if (tp->flags & TP_FLAG_PROFILE)
1915 kretprobe_perf_func(ri, regs);
1916 #endif
1917 return 0; /* We don't tweek kernel, so just return 0 */
1918 }
1919
1920 static struct trace_event_functions kretprobe_funcs = {
1921 .trace = print_kretprobe_event
1922 };
1923
1924 static struct trace_event_functions kprobe_funcs = {
1925 .trace = print_kprobe_event
1926 };
1927
1928 static int register_probe_event(struct trace_probe *tp)
1929 {
1930 struct ftrace_event_call *call = &tp->call;
1931 int ret;
1932
1933 /* Initialize ftrace_event_call */
1934 INIT_LIST_HEAD(&call->class->fields);
1935 if (trace_probe_is_return(tp)) {
1936 call->event.funcs = &kretprobe_funcs;
1937 call->class->define_fields = kretprobe_event_define_fields;
1938 } else {
1939 call->event.funcs = &kprobe_funcs;
1940 call->class->define_fields = kprobe_event_define_fields;
1941 }
1942 if (set_print_fmt(tp) < 0)
1943 return -ENOMEM;
1944 ret = register_ftrace_event(&call->event);
1945 if (!ret) {
1946 kfree(call->print_fmt);
1947 return -ENODEV;
1948 }
1949 call->flags = 0;
1950 call->class->reg = kprobe_register;
1951 call->data = tp;
1952 ret = trace_add_event_call(call);
1953 if (ret) {
1954 pr_info("Failed to register kprobe event: %s\n", call->name);
1955 kfree(call->print_fmt);
1956 unregister_ftrace_event(&call->event);
1957 }
1958 return ret;
1959 }
1960
1961 static void unregister_probe_event(struct trace_probe *tp)
1962 {
1963 /* tp->event is unregistered in trace_remove_event_call() */
1964 trace_remove_event_call(&tp->call);
1965 kfree(tp->call.print_fmt);
1966 }
1967
1968 /* Make a debugfs interface for controlling probe points */
1969 static __init int init_kprobe_trace(void)
1970 {
1971 struct dentry *d_tracer;
1972 struct dentry *entry;
1973
1974 if (register_module_notifier(&trace_probe_module_nb))
1975 return -EINVAL;
1976
1977 d_tracer = tracing_init_dentry();
1978 if (!d_tracer)
1979 return 0;
1980
1981 entry = debugfs_create_file("kprobe_events", 0644, d_tracer,
1982 NULL, &kprobe_events_ops);
1983
1984 /* Event list interface */
1985 if (!entry)
1986 pr_warning("Could not create debugfs "
1987 "'kprobe_events' entry\n");
1988
1989 /* Profile interface */
1990 entry = debugfs_create_file("kprobe_profile", 0444, d_tracer,
1991 NULL, &kprobe_profile_ops);
1992
1993 if (!entry)
1994 pr_warning("Could not create debugfs "
1995 "'kprobe_profile' entry\n");
1996 return 0;
1997 }
1998 fs_initcall(init_kprobe_trace);
1999
2000
2001 #ifdef CONFIG_FTRACE_STARTUP_TEST
2002
2003 /*
2004 * The "__used" keeps gcc from removing the function symbol
2005 * from the kallsyms table.
2006 */
2007 static __used int kprobe_trace_selftest_target(int a1, int a2, int a3,
2008 int a4, int a5, int a6)
2009 {
2010 return a1 + a2 + a3 + a4 + a5 + a6;
2011 }
2012
2013 static __init int kprobe_trace_self_tests_init(void)
2014 {
2015 int ret, warn = 0;
2016 int (*target)(int, int, int, int, int, int);
2017 struct trace_probe *tp;
2018
2019 target = kprobe_trace_selftest_target;
2020
2021 pr_info("Testing kprobe tracing: ");
2022
2023 ret = command_trace_probe("p:testprobe kprobe_trace_selftest_target "
2024 "$stack $stack0 +0($stack)");
2025 if (WARN_ON_ONCE(ret)) {
2026 pr_warning("error on probing function entry.\n");
2027 warn++;
2028 } else {
2029 /* Enable trace point */
2030 tp = find_trace_probe("testprobe", KPROBE_EVENT_SYSTEM);
2031 if (WARN_ON_ONCE(tp == NULL)) {
2032 pr_warning("error on getting new probe.\n");
2033 warn++;
2034 } else
2035 enable_trace_probe(tp, TP_FLAG_TRACE);
2036 }
2037
2038 ret = command_trace_probe("r:testprobe2 kprobe_trace_selftest_target "
2039 "$retval");
2040 if (WARN_ON_ONCE(ret)) {
2041 pr_warning("error on probing function return.\n");
2042 warn++;
2043 } else {
2044 /* Enable trace point */
2045 tp = find_trace_probe("testprobe2", KPROBE_EVENT_SYSTEM);
2046 if (WARN_ON_ONCE(tp == NULL)) {
2047 pr_warning("error on getting new probe.\n");
2048 warn++;
2049 } else
2050 enable_trace_probe(tp, TP_FLAG_TRACE);
2051 }
2052
2053 if (warn)
2054 goto end;
2055
2056 ret = target(1, 2, 3, 4, 5, 6);
2057
2058 ret = command_trace_probe("-:testprobe");
2059 if (WARN_ON_ONCE(ret)) {
2060 pr_warning("error on deleting a probe.\n");
2061 warn++;
2062 }
2063
2064 ret = command_trace_probe("-:testprobe2");
2065 if (WARN_ON_ONCE(ret)) {
2066 pr_warning("error on deleting a probe.\n");
2067 warn++;
2068 }
2069
2070 end:
2071 release_all_trace_probes();
2072 if (warn)
2073 pr_cont("NG: Some tests are failed. Please check them.\n");
2074 else
2075 pr_cont("OK\n");
2076 return 0;
2077 }
2078
2079 late_initcall(kprobe_trace_self_tests_init);
2080
2081 #endif
linux-next