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firewire: ohci: sanity-check MMIO resource
[linux-2.6.git] / kernel / trace / trace_kprobe.c
blob580a05ec926b46acad474f729f76b62845c8e200
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 int unregister_trace_probe(struct trace_probe *tp)
840 {
841 /* Enabled event can not be unregistered */
842 if (trace_probe_is_enabled(tp))
843 return -EBUSY;
844
845 __unregister_trace_probe(tp);
846 list_del(&tp->list);
847 unregister_probe_event(tp);
848
849 return 0;
850 }
851
852 /* Register a trace_probe and probe_event */
853 static int register_trace_probe(struct trace_probe *tp)
854 {
855 struct trace_probe *old_tp;
856 int ret;
857
858 mutex_lock(&probe_lock);
859
860 /* Delete old (same name) event if exist */
861 old_tp = find_trace_probe(tp->call.name, tp->call.class->system);
862 if (old_tp) {
863 ret = unregister_trace_probe(old_tp);
864 if (ret < 0)
865 goto end;
866 free_trace_probe(old_tp);
867 }
868
869 /* Register new event */
870 ret = register_probe_event(tp);
871 if (ret) {
872 pr_warning("Failed to register probe event(%d)\n", ret);
873 goto end;
874 }
875
876 /* Register k*probe */
877 ret = __register_trace_probe(tp);
878 if (ret < 0)
879 unregister_probe_event(tp);
880 else
881 list_add_tail(&tp->list, &probe_list);
882
883 end:
884 mutex_unlock(&probe_lock);
885 return ret;
886 }
887
888 /* Module notifier call back, checking event on the module */
889 static int trace_probe_module_callback(struct notifier_block *nb,
890 unsigned long val, void *data)
891 {
892 struct module *mod = data;
893 struct trace_probe *tp;
894 int ret;
895
896 if (val != MODULE_STATE_COMING)
897 return NOTIFY_DONE;
898
899 /* Update probes on coming module */
900 mutex_lock(&probe_lock);
901 list_for_each_entry(tp, &probe_list, list) {
902 if (trace_probe_within_module(tp, mod)) {
903 /* Don't need to check busy - this should have gone. */
904 __unregister_trace_probe(tp);
905 ret = __register_trace_probe(tp);
906 if (ret)
907 pr_warning("Failed to re-register probe %s on"
908 "%s: %d\n",
909 tp->call.name, mod->name, ret);
910 }
911 }
912 mutex_unlock(&probe_lock);
913
914 return NOTIFY_DONE;
915 }
916
917 static struct notifier_block trace_probe_module_nb = {
918 .notifier_call = trace_probe_module_callback,
919 .priority = 1 /* Invoked after kprobe module callback */
920 };
921
922 /* Split symbol and offset. */
923 static int split_symbol_offset(char *symbol, unsigned long *offset)
924 {
925 char *tmp;
926 int ret;
927
928 if (!offset)
929 return -EINVAL;
930
931 tmp = strchr(symbol, '+');
932 if (tmp) {
933 /* skip sign because strict_strtol doesn't accept '+' */
934 ret = strict_strtoul(tmp + 1, 0, offset);
935 if (ret)
936 return ret;
937 *tmp = '\0';
938 } else
939 *offset = 0;
940 return 0;
941 }
942
943 #define PARAM_MAX_ARGS 16
944 #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
945
946 static int parse_probe_vars(char *arg, const struct fetch_type *t,
947 struct fetch_param *f, int is_return)
948 {
949 int ret = 0;
950 unsigned long param;
951
952 if (strcmp(arg, "retval") == 0) {
953 if (is_return)
954 f->fn = t->fetch[FETCH_MTD_retval];
955 else
956 ret = -EINVAL;
957 } else if (strncmp(arg, "stack", 5) == 0) {
958 if (arg[5] == '\0') {
959 if (strcmp(t->name, DEFAULT_FETCH_TYPE_STR) == 0)
960 f->fn = fetch_stack_address;
961 else
962 ret = -EINVAL;
963 } else if (isdigit(arg[5])) {
964 ret = strict_strtoul(arg + 5, 10, &param);
965 if (ret || param > PARAM_MAX_STACK)
966 ret = -EINVAL;
967 else {
968 f->fn = t->fetch[FETCH_MTD_stack];
969 f->data = (void *)param;
970 }
971 } else
972 ret = -EINVAL;
973 } else
974 ret = -EINVAL;
975 return ret;
976 }
977
978 /* Recursive argument parser */
979 static int __parse_probe_arg(char *arg, const struct fetch_type *t,
980 struct fetch_param *f, int is_return)
981 {
982 int ret = 0;
983 unsigned long param;
984 long offset;
985 char *tmp;
986
987 switch (arg[0]) {
988 case '$':
989 ret = parse_probe_vars(arg + 1, t, f, is_return);
990 break;
991 case '%': /* named register */
992 ret = regs_query_register_offset(arg + 1);
993 if (ret >= 0) {
994 f->fn = t->fetch[FETCH_MTD_reg];
995 f->data = (void *)(unsigned long)ret;
996 ret = 0;
997 }
998 break;
999 case '@': /* memory or symbol */
1000 if (isdigit(arg[1])) {
1001 ret = strict_strtoul(arg + 1, 0, &param);
1002 if (ret)
1003 break;
1004 f->fn = t->fetch[FETCH_MTD_memory];
1005 f->data = (void *)param;
1006 } else {
1007 ret = split_symbol_offset(arg + 1, &offset);
1008 if (ret)
1009 break;
1010 f->data = alloc_symbol_cache(arg + 1, offset);
1011 if (f->data)
1012 f->fn = t->fetch[FETCH_MTD_symbol];
1013 }
1014 break;
1015 case '+': /* deref memory */
1016 arg++; /* Skip '+', because strict_strtol() rejects it. */
1017 case '-':
1018 tmp = strchr(arg, '(');
1019 if (!tmp)
1020 break;
1021 *tmp = '\0';
1022 ret = strict_strtol(arg, 0, &offset);
1023 if (ret)
1024 break;
1025 arg = tmp + 1;
1026 tmp = strrchr(arg, ')');
1027 if (tmp) {
1028 struct deref_fetch_param *dprm;
1029 const struct fetch_type *t2 = find_fetch_type(NULL);
1030 *tmp = '\0';
1031 dprm = kzalloc(sizeof(struct deref_fetch_param),
1032 GFP_KERNEL);
1033 if (!dprm)
1034 return -ENOMEM;
1035 dprm->offset = offset;
1036 ret = __parse_probe_arg(arg, t2, &dprm->orig,
1037 is_return);
1038 if (ret)
1039 kfree(dprm);
1040 else {
1041 f->fn = t->fetch[FETCH_MTD_deref];
1042 f->data = (void *)dprm;
1043 }
1044 }
1045 break;
1046 }
1047 if (!ret && !f->fn) { /* Parsed, but do not find fetch method */
1048 pr_info("%s type has no corresponding fetch method.\n",
1049 t->name);
1050 ret = -EINVAL;
1051 }
1052 return ret;
1053 }
1054
1055 #define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long))
1056
1057 /* Bitfield type needs to be parsed into a fetch function */
1058 static int __parse_bitfield_probe_arg(const char *bf,
1059 const struct fetch_type *t,
1060 struct fetch_param *f)
1061 {
1062 struct bitfield_fetch_param *bprm;
1063 unsigned long bw, bo;
1064 char *tail;
1065
1066 if (*bf != 'b')
1067 return 0;
1068
1069 bprm = kzalloc(sizeof(*bprm), GFP_KERNEL);
1070 if (!bprm)
1071 return -ENOMEM;
1072 bprm->orig = *f;
1073 f->fn = t->fetch[FETCH_MTD_bitfield];
1074 f->data = (void *)bprm;
1075
1076 bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */
1077 if (bw == 0 || *tail != '@')
1078 return -EINVAL;
1079
1080 bf = tail + 1;
1081 bo = simple_strtoul(bf, &tail, 0);
1082 if (tail == bf || *tail != '/')
1083 return -EINVAL;
1084
1085 bprm->hi_shift = BYTES_TO_BITS(t->size) - (bw + bo);
1086 bprm->low_shift = bprm->hi_shift + bo;
1087 return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0;
1088 }
1089
1090 /* String length checking wrapper */
1091 static int parse_probe_arg(char *arg, struct trace_probe *tp,
1092 struct probe_arg *parg, int is_return)
1093 {
1094 const char *t;
1095 int ret;
1096
1097 if (strlen(arg) > MAX_ARGSTR_LEN) {
1098 pr_info("Argument is too long.: %s\n", arg);
1099 return -ENOSPC;
1100 }
1101 parg->comm = kstrdup(arg, GFP_KERNEL);
1102 if (!parg->comm) {
1103 pr_info("Failed to allocate memory for command '%s'.\n", arg);
1104 return -ENOMEM;
1105 }
1106 t = strchr(parg->comm, ':');
1107 if (t) {
1108 arg[t - parg->comm] = '\0';
1109 t++;
1110 }
1111 parg->type = find_fetch_type(t);
1112 if (!parg->type) {
1113 pr_info("Unsupported type: %s\n", t);
1114 return -EINVAL;
1115 }
1116 parg->offset = tp->size;
1117 tp->size += parg->type->size;
1118 ret = __parse_probe_arg(arg, parg->type, &parg->fetch, is_return);
1119 if (ret >= 0 && t != NULL)
1120 ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch);
1121 if (ret >= 0) {
1122 parg->fetch_size.fn = get_fetch_size_function(parg->type,
1123 parg->fetch.fn);
1124 parg->fetch_size.data = parg->fetch.data;
1125 }
1126 return ret;
1127 }
1128
1129 /* Return 1 if name is reserved or already used by another argument */
1130 static int conflict_field_name(const char *name,
1131 struct probe_arg *args, int narg)
1132 {
1133 int i;
1134 for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++)
1135 if (strcmp(reserved_field_names[i], name) == 0)
1136 return 1;
1137 for (i = 0; i < narg; i++)
1138 if (strcmp(args[i].name, name) == 0)
1139 return 1;
1140 return 0;
1141 }
1142
1143 static int create_trace_probe(int argc, char **argv)
1144 {
1145 /*
1146 * Argument syntax:
1147 * - Add kprobe: p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS]
1148 * - Add kretprobe: r[:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS]
1149 * Fetch args:
1150 * $retval : fetch return value
1151 * $stack : fetch stack address
1152 * $stackN : fetch Nth of stack (N:0-)
1153 * @ADDR : fetch memory at ADDR (ADDR should be in kernel)
1154 * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol)
1155 * %REG : fetch register REG
1156 * Dereferencing memory fetch:
1157 * +|-offs(ARG) : fetch memory at ARG +|- offs address.
1158 * Alias name of args:
1159 * NAME=FETCHARG : set NAME as alias of FETCHARG.
1160 * Type of args:
1161 * FETCHARG:TYPE : use TYPE instead of unsigned long.
1162 */
1163 struct trace_probe *tp;
1164 int i, ret = 0;
1165 int is_return = 0, is_delete = 0;
1166 char *symbol = NULL, *event = NULL, *group = NULL;
1167 char *arg;
1168 unsigned long offset = 0;
1169 void *addr = NULL;
1170 char buf[MAX_EVENT_NAME_LEN];
1171
1172 /* argc must be >= 1 */
1173 if (argv[0][0] == 'p')
1174 is_return = 0;
1175 else if (argv[0][0] == 'r')
1176 is_return = 1;
1177 else if (argv[0][0] == '-')
1178 is_delete = 1;
1179 else {
1180 pr_info("Probe definition must be started with 'p', 'r' or"
1181 " '-'.\n");
1182 return -EINVAL;
1183 }
1184
1185 if (argv[0][1] == ':') {
1186 event = &argv[0][2];
1187 if (strchr(event, '/')) {
1188 group = event;
1189 event = strchr(group, '/') + 1;
1190 event[-1] = '\0';
1191 if (strlen(group) == 0) {
1192 pr_info("Group name is not specified\n");
1193 return -EINVAL;
1194 }
1195 }
1196 if (strlen(event) == 0) {
1197 pr_info("Event name is not specified\n");
1198 return -EINVAL;
1199 }
1200 }
1201 if (!group)
1202 group = KPROBE_EVENT_SYSTEM;
1203
1204 if (is_delete) {
1205 if (!event) {
1206 pr_info("Delete command needs an event name.\n");
1207 return -EINVAL;
1208 }
1209 mutex_lock(&probe_lock);
1210 tp = find_trace_probe(event, group);
1211 if (!tp) {
1212 mutex_unlock(&probe_lock);
1213 pr_info("Event %s/%s doesn't exist.\n", group, event);
1214 return -ENOENT;
1215 }
1216 /* delete an event */
1217 ret = unregister_trace_probe(tp);
1218 if (ret == 0)
1219 free_trace_probe(tp);
1220 mutex_unlock(&probe_lock);
1221 return ret;
1222 }
1223
1224 if (argc < 2) {
1225 pr_info("Probe point is not specified.\n");
1226 return -EINVAL;
1227 }
1228 if (isdigit(argv[1][0])) {
1229 if (is_return) {
1230 pr_info("Return probe point must be a symbol.\n");
1231 return -EINVAL;
1232 }
1233 /* an address specified */
1234 ret = strict_strtoul(&argv[1][0], 0, (unsigned long *)&addr);
1235 if (ret) {
1236 pr_info("Failed to parse address.\n");
1237 return ret;
1238 }
1239 } else {
1240 /* a symbol specified */
1241 symbol = argv[1];
1242 /* TODO: support .init module functions */
1243 ret = split_symbol_offset(symbol, &offset);
1244 if (ret) {
1245 pr_info("Failed to parse symbol.\n");
1246 return ret;
1247 }
1248 if (offset && is_return) {
1249 pr_info("Return probe must be used without offset.\n");
1250 return -EINVAL;
1251 }
1252 }
1253 argc -= 2; argv += 2;
1254
1255 /* setup a probe */
1256 if (!event) {
1257 /* Make a new event name */
1258 if (symbol)
1259 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld",
1260 is_return ? 'r' : 'p', symbol, offset);
1261 else
1262 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p",
1263 is_return ? 'r' : 'p', addr);
1264 event = buf;
1265 }
1266 tp = alloc_trace_probe(group, event, addr, symbol, offset, argc,
1267 is_return);
1268 if (IS_ERR(tp)) {
1269 pr_info("Failed to allocate trace_probe.(%d)\n",
1270 (int)PTR_ERR(tp));
1271 return PTR_ERR(tp);
1272 }
1273
1274 /* parse arguments */
1275 ret = 0;
1276 for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
1277 /* Increment count for freeing args in error case */
1278 tp->nr_args++;
1279
1280 /* Parse argument name */
1281 arg = strchr(argv[i], '=');
1282 if (arg) {
1283 *arg++ = '\0';
1284 tp->args[i].name = kstrdup(argv[i], GFP_KERNEL);
1285 } else {
1286 arg = argv[i];
1287 /* If argument name is omitted, set "argN" */
1288 snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1);
1289 tp->args[i].name = kstrdup(buf, GFP_KERNEL);
1290 }
1291
1292 if (!tp->args[i].name) {
1293 pr_info("Failed to allocate argument[%d] name.\n", i);
1294 ret = -ENOMEM;
1295 goto error;
1296 }
1297
1298 if (!is_good_name(tp->args[i].name)) {
1299 pr_info("Invalid argument[%d] name: %s\n",
1300 i, tp->args[i].name);
1301 ret = -EINVAL;
1302 goto error;
1303 }
1304
1305 if (conflict_field_name(tp->args[i].name, tp->args, i)) {
1306 pr_info("Argument[%d] name '%s' conflicts with "
1307 "another field.\n", i, argv[i]);
1308 ret = -EINVAL;
1309 goto error;
1310 }
1311
1312 /* Parse fetch argument */
1313 ret = parse_probe_arg(arg, tp, &tp->args[i], is_return);
1314 if (ret) {
1315 pr_info("Parse error at argument[%d]. (%d)\n", i, ret);
1316 goto error;
1317 }
1318 }
1319
1320 ret = register_trace_probe(tp);
1321 if (ret)
1322 goto error;
1323 return 0;
1324
1325 error:
1326 free_trace_probe(tp);
1327 return ret;
1328 }
1329
1330 static int release_all_trace_probes(void)
1331 {
1332 struct trace_probe *tp;
1333 int ret = 0;
1334
1335 mutex_lock(&probe_lock);
1336 /* Ensure no probe is in use. */
1337 list_for_each_entry(tp, &probe_list, list)
1338 if (trace_probe_is_enabled(tp)) {
1339 ret = -EBUSY;
1340 goto end;
1341 }
1342 /* TODO: Use batch unregistration */
1343 while (!list_empty(&probe_list)) {
1344 tp = list_entry(probe_list.next, struct trace_probe, list);
1345 unregister_trace_probe(tp);
1346 free_trace_probe(tp);
1347 }
1348
1349 end:
1350 mutex_unlock(&probe_lock);
1351
1352 return ret;
1353 }
1354
1355 /* Probes listing interfaces */
1356 static void *probes_seq_start(struct seq_file *m, loff_t *pos)
1357 {
1358 mutex_lock(&probe_lock);
1359 return seq_list_start(&probe_list, *pos);
1360 }
1361
1362 static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos)
1363 {
1364 return seq_list_next(v, &probe_list, pos);
1365 }
1366
1367 static void probes_seq_stop(struct seq_file *m, void *v)
1368 {
1369 mutex_unlock(&probe_lock);
1370 }
1371
1372 static int probes_seq_show(struct seq_file *m, void *v)
1373 {
1374 struct trace_probe *tp = v;
1375 int i;
1376
1377 seq_printf(m, "%c", trace_probe_is_return(tp) ? 'r' : 'p');
1378 seq_printf(m, ":%s/%s", tp->call.class->system, tp->call.name);
1379
1380 if (!tp->symbol)
1381 seq_printf(m, " 0x%p", tp->rp.kp.addr);
1382 else if (tp->rp.kp.offset)
1383 seq_printf(m, " %s+%u", trace_probe_symbol(tp),
1384 tp->rp.kp.offset);
1385 else
1386 seq_printf(m, " %s", trace_probe_symbol(tp));
1387
1388 for (i = 0; i < tp->nr_args; i++)
1389 seq_printf(m, " %s=%s", tp->args[i].name, tp->args[i].comm);
1390 seq_printf(m, "\n");
1391
1392 return 0;
1393 }
1394
1395 static const struct seq_operations probes_seq_op = {
1396 .start = probes_seq_start,
1397 .next = probes_seq_next,
1398 .stop = probes_seq_stop,
1399 .show = probes_seq_show
1400 };
1401
1402 static int probes_open(struct inode *inode, struct file *file)
1403 {
1404 int ret;
1405
1406 if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
1407 ret = release_all_trace_probes();
1408 if (ret < 0)
1409 return ret;
1410 }
1411
1412 return seq_open(file, &probes_seq_op);
1413 }
1414
1415 static int command_trace_probe(const char *buf)
1416 {
1417 char **argv;
1418 int argc = 0, ret = 0;
1419
1420 argv = argv_split(GFP_KERNEL, buf, &argc);
1421 if (!argv)
1422 return -ENOMEM;
1423
1424 if (argc)
1425 ret = create_trace_probe(argc, argv);
1426
1427 argv_free(argv);
1428 return ret;
1429 }
1430
1431 #define WRITE_BUFSIZE 4096
1432
1433 static ssize_t probes_write(struct file *file, const char __user *buffer,
1434 size_t count, loff_t *ppos)
1435 {
1436 char *kbuf, *tmp;
1437 int ret;
1438 size_t done;
1439 size_t size;
1440
1441 kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL);
1442 if (!kbuf)
1443 return -ENOMEM;
1444
1445 ret = done = 0;
1446 while (done < count) {
1447 size = count - done;
1448 if (size >= WRITE_BUFSIZE)
1449 size = WRITE_BUFSIZE - 1;
1450 if (copy_from_user(kbuf, buffer + done, size)) {
1451 ret = -EFAULT;
1452 goto out;
1453 }
1454 kbuf[size] = '\0';
1455 tmp = strchr(kbuf, '\n');
1456 if (tmp) {
1457 *tmp = '\0';
1458 size = tmp - kbuf + 1;
1459 } else if (done + size < count) {
1460 pr_warning("Line length is too long: "
1461 "Should be less than %d.", WRITE_BUFSIZE);
1462 ret = -EINVAL;
1463 goto out;
1464 }
1465 done += size;
1466 /* Remove comments */
1467 tmp = strchr(kbuf, '#');
1468 if (tmp)
1469 *tmp = '\0';
1470
1471 ret = command_trace_probe(kbuf);
1472 if (ret)
1473 goto out;
1474 }
1475 ret = done;
1476 out:
1477 kfree(kbuf);
1478 return ret;
1479 }
1480
1481 static const struct file_operations kprobe_events_ops = {
1482 .owner = THIS_MODULE,
1483 .open = probes_open,
1484 .read = seq_read,
1485 .llseek = seq_lseek,
1486 .release = seq_release,
1487 .write = probes_write,
1488 };
1489
1490 /* Probes profiling interfaces */
1491 static int probes_profile_seq_show(struct seq_file *m, void *v)
1492 {
1493 struct trace_probe *tp = v;
1494
1495 seq_printf(m, " %-44s %15lu %15lu\n", tp->call.name, tp->nhit,
1496 tp->rp.kp.nmissed);
1497
1498 return 0;
1499 }
1500
1501 static const struct seq_operations profile_seq_op = {
1502 .start = probes_seq_start,
1503 .next = probes_seq_next,
1504 .stop = probes_seq_stop,
1505 .show = probes_profile_seq_show
1506 };
1507
1508 static int profile_open(struct inode *inode, struct file *file)
1509 {
1510 return seq_open(file, &profile_seq_op);
1511 }
1512
1513 static const struct file_operations kprobe_profile_ops = {
1514 .owner = THIS_MODULE,
1515 .open = profile_open,
1516 .read = seq_read,
1517 .llseek = seq_lseek,
1518 .release = seq_release,
1519 };
1520
1521 /* Sum up total data length for dynamic arraies (strings) */
1522 static __kprobes int __get_data_size(struct trace_probe *tp,
1523 struct pt_regs *regs)
1524 {
1525 int i, ret = 0;
1526 u32 len;
1527
1528 for (i = 0; i < tp->nr_args; i++)
1529 if (unlikely(tp->args[i].fetch_size.fn)) {
1530 call_fetch(&tp->args[i].fetch_size, regs, &len);
1531 ret += len;
1532 }
1533
1534 return ret;
1535 }
1536
1537 /* Store the value of each argument */
1538 static __kprobes void store_trace_args(int ent_size, struct trace_probe *tp,
1539 struct pt_regs *regs,
1540 u8 *data, int maxlen)
1541 {
1542 int i;
1543 u32 end = tp->size;
1544 u32 *dl; /* Data (relative) location */
1545
1546 for (i = 0; i < tp->nr_args; i++) {
1547 if (unlikely(tp->args[i].fetch_size.fn)) {
1548 /*
1549 * First, we set the relative location and
1550 * maximum data length to *dl
1551 */
1552 dl = (u32 *)(data + tp->args[i].offset);
1553 *dl = make_data_rloc(maxlen, end - tp->args[i].offset);
1554 /* Then try to fetch string or dynamic array data */
1555 call_fetch(&tp->args[i].fetch, regs, dl);
1556 /* Reduce maximum length */
1557 end += get_rloc_len(*dl);
1558 maxlen -= get_rloc_len(*dl);
1559 /* Trick here, convert data_rloc to data_loc */
1560 *dl = convert_rloc_to_loc(*dl,
1561 ent_size + tp->args[i].offset);
1562 } else
1563 /* Just fetching data normally */
1564 call_fetch(&tp->args[i].fetch, regs,
1565 data + tp->args[i].offset);
1566 }
1567 }
1568
1569 /* Kprobe handler */
1570 static __kprobes void kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs)
1571 {
1572 struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
1573 struct kprobe_trace_entry_head *entry;
1574 struct ring_buffer_event *event;
1575 struct ring_buffer *buffer;
1576 int size, dsize, pc;
1577 unsigned long irq_flags;
1578 struct ftrace_event_call *call = &tp->call;
1579
1580 tp->nhit++;
1581
1582 local_save_flags(irq_flags);
1583 pc = preempt_count();
1584
1585 dsize = __get_data_size(tp, regs);
1586 size = sizeof(*entry) + tp->size + dsize;
1587
1588 event = trace_current_buffer_lock_reserve(&buffer, call->event.type,
1589 size, irq_flags, pc);
1590 if (!event)
1591 return;
1592
1593 entry = ring_buffer_event_data(event);
1594 entry->ip = (unsigned long)kp->addr;
1595 store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize);
1596
1597 if (!filter_current_check_discard(buffer, call, entry, event))
1598 trace_nowake_buffer_unlock_commit_regs(buffer, event,
1599 irq_flags, pc, regs);
1600 }
1601
1602 /* Kretprobe handler */
1603 static __kprobes void kretprobe_trace_func(struct kretprobe_instance *ri,
1604 struct pt_regs *regs)
1605 {
1606 struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
1607 struct kretprobe_trace_entry_head *entry;
1608 struct ring_buffer_event *event;
1609 struct ring_buffer *buffer;
1610 int size, pc, dsize;
1611 unsigned long irq_flags;
1612 struct ftrace_event_call *call = &tp->call;
1613
1614 local_save_flags(irq_flags);
1615 pc = preempt_count();
1616
1617 dsize = __get_data_size(tp, regs);
1618 size = sizeof(*entry) + tp->size + dsize;
1619
1620 event = trace_current_buffer_lock_reserve(&buffer, call->event.type,
1621 size, irq_flags, pc);
1622 if (!event)
1623 return;
1624
1625 entry = ring_buffer_event_data(event);
1626 entry->func = (unsigned long)tp->rp.kp.addr;
1627 entry->ret_ip = (unsigned long)ri->ret_addr;
1628 store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize);
1629
1630 if (!filter_current_check_discard(buffer, call, entry, event))
1631 trace_nowake_buffer_unlock_commit_regs(buffer, event,
1632 irq_flags, pc, regs);
1633 }
1634
1635 /* Event entry printers */
1636 enum print_line_t
1637 print_kprobe_event(struct trace_iterator *iter, int flags,
1638 struct trace_event *event)
1639 {
1640 struct kprobe_trace_entry_head *field;
1641 struct trace_seq *s = &iter->seq;
1642 struct trace_probe *tp;
1643 u8 *data;
1644 int i;
1645
1646 field = (struct kprobe_trace_entry_head *)iter->ent;
1647 tp = container_of(event, struct trace_probe, call.event);
1648
1649 if (!trace_seq_printf(s, "%s: (", tp->call.name))
1650 goto partial;
1651
1652 if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET))
1653 goto partial;
1654
1655 if (!trace_seq_puts(s, ")"))
1656 goto partial;
1657
1658 data = (u8 *)&field[1];
1659 for (i = 0; i < tp->nr_args; i++)
1660 if (!tp->args[i].type->print(s, tp->args[i].name,
1661 data + tp->args[i].offset, field))
1662 goto partial;
1663
1664 if (!trace_seq_puts(s, "\n"))
1665 goto partial;
1666
1667 return TRACE_TYPE_HANDLED;
1668 partial:
1669 return TRACE_TYPE_PARTIAL_LINE;
1670 }
1671
1672 enum print_line_t
1673 print_kretprobe_event(struct trace_iterator *iter, int flags,
1674 struct trace_event *event)
1675 {
1676 struct kretprobe_trace_entry_head *field;
1677 struct trace_seq *s = &iter->seq;
1678 struct trace_probe *tp;
1679 u8 *data;
1680 int i;
1681
1682 field = (struct kretprobe_trace_entry_head *)iter->ent;
1683 tp = container_of(event, struct trace_probe, call.event);
1684
1685 if (!trace_seq_printf(s, "%s: (", tp->call.name))
1686 goto partial;
1687
1688 if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET))
1689 goto partial;
1690
1691 if (!trace_seq_puts(s, " <- "))
1692 goto partial;
1693
1694 if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET))
1695 goto partial;
1696
1697 if (!trace_seq_puts(s, ")"))
1698 goto partial;
1699
1700 data = (u8 *)&field[1];
1701 for (i = 0; i < tp->nr_args; i++)
1702 if (!tp->args[i].type->print(s, tp->args[i].name,
1703 data + tp->args[i].offset, field))
1704 goto partial;
1705
1706 if (!trace_seq_puts(s, "\n"))
1707 goto partial;
1708
1709 return TRACE_TYPE_HANDLED;
1710 partial:
1711 return TRACE_TYPE_PARTIAL_LINE;
1712 }
1713
1714 #undef DEFINE_FIELD
1715 #define DEFINE_FIELD(type, item, name, is_signed) \
1716 do { \
1717 ret = trace_define_field(event_call, #type, name, \
1718 offsetof(typeof(field), item), \
1719 sizeof(field.item), is_signed, \
1720 FILTER_OTHER); \
1721 if (ret) \
1722 return ret; \
1723 } while (0)
1724
1725 static int kprobe_event_define_fields(struct ftrace_event_call *event_call)
1726 {
1727 int ret, i;
1728 struct kprobe_trace_entry_head field;
1729 struct trace_probe *tp = (struct trace_probe *)event_call->data;
1730
1731 DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0);
1732 /* Set argument names as fields */
1733 for (i = 0; i < tp->nr_args; i++) {
1734 ret = trace_define_field(event_call, tp->args[i].type->fmttype,
1735 tp->args[i].name,
1736 sizeof(field) + tp->args[i].offset,
1737 tp->args[i].type->size,
1738 tp->args[i].type->is_signed,
1739 FILTER_OTHER);
1740 if (ret)
1741 return ret;
1742 }
1743 return 0;
1744 }
1745
1746 static int kretprobe_event_define_fields(struct ftrace_event_call *event_call)
1747 {
1748 int ret, i;
1749 struct kretprobe_trace_entry_head field;
1750 struct trace_probe *tp = (struct trace_probe *)event_call->data;
1751
1752 DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0);
1753 DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0);
1754 /* Set argument names as fields */
1755 for (i = 0; i < tp->nr_args; i++) {
1756 ret = trace_define_field(event_call, tp->args[i].type->fmttype,
1757 tp->args[i].name,
1758 sizeof(field) + tp->args[i].offset,
1759 tp->args[i].type->size,
1760 tp->args[i].type->is_signed,
1761 FILTER_OTHER);
1762 if (ret)
1763 return ret;
1764 }
1765 return 0;
1766 }
1767
1768 static int __set_print_fmt(struct trace_probe *tp, char *buf, int len)
1769 {
1770 int i;
1771 int pos = 0;
1772
1773 const char *fmt, *arg;
1774
1775 if (!trace_probe_is_return(tp)) {
1776 fmt = "(%lx)";
1777 arg = "REC->" FIELD_STRING_IP;
1778 } else {
1779 fmt = "(%lx <- %lx)";
1780 arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP;
1781 }
1782
1783 /* When len=0, we just calculate the needed length */
1784 #define LEN_OR_ZERO (len ? len - pos : 0)
1785
1786 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt);
1787
1788 for (i = 0; i < tp->nr_args; i++) {
1789 pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%s",
1790 tp->args[i].name, tp->args[i].type->fmt);
1791 }
1792
1793 pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg);
1794
1795 for (i = 0; i < tp->nr_args; i++) {
1796 if (strcmp(tp->args[i].type->name, "string") == 0)
1797 pos += snprintf(buf + pos, LEN_OR_ZERO,
1798 ", __get_str(%s)",
1799 tp->args[i].name);
1800 else
1801 pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s",
1802 tp->args[i].name);
1803 }
1804
1805 #undef LEN_OR_ZERO
1806
1807 /* return the length of print_fmt */
1808 return pos;
1809 }
1810
1811 static int set_print_fmt(struct trace_probe *tp)
1812 {
1813 int len;
1814 char *print_fmt;
1815
1816 /* First: called with 0 length to calculate the needed length */
1817 len = __set_print_fmt(tp, NULL, 0);
1818 print_fmt = kmalloc(len + 1, GFP_KERNEL);
1819 if (!print_fmt)
1820 return -ENOMEM;
1821
1822 /* Second: actually write the @print_fmt */
1823 __set_print_fmt(tp, print_fmt, len + 1);
1824 tp->call.print_fmt = print_fmt;
1825
1826 return 0;
1827 }
1828
1829 #ifdef CONFIG_PERF_EVENTS
1830
1831 /* Kprobe profile handler */
1832 static __kprobes void kprobe_perf_func(struct kprobe *kp,
1833 struct pt_regs *regs)
1834 {
1835 struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
1836 struct ftrace_event_call *call = &tp->call;
1837 struct kprobe_trace_entry_head *entry;
1838 struct hlist_head *head;
1839 int size, __size, dsize;
1840 int rctx;
1841
1842 dsize = __get_data_size(tp, regs);
1843 __size = sizeof(*entry) + tp->size + dsize;
1844 size = ALIGN(__size + sizeof(u32), sizeof(u64));
1845 size -= sizeof(u32);
1846 if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
1847 "profile buffer not large enough"))
1848 return;
1849
1850 entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx);
1851 if (!entry)
1852 return;
1853
1854 entry->ip = (unsigned long)kp->addr;
1855 memset(&entry[1], 0, dsize);
1856 store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize);
1857
1858 head = this_cpu_ptr(call->perf_events);
1859 perf_trace_buf_submit(entry, size, rctx, entry->ip, 1, regs, head);
1860 }
1861
1862 /* Kretprobe profile handler */
1863 static __kprobes void kretprobe_perf_func(struct kretprobe_instance *ri,
1864 struct pt_regs *regs)
1865 {
1866 struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
1867 struct ftrace_event_call *call = &tp->call;
1868 struct kretprobe_trace_entry_head *entry;
1869 struct hlist_head *head;
1870 int size, __size, dsize;
1871 int rctx;
1872
1873 dsize = __get_data_size(tp, regs);
1874 __size = sizeof(*entry) + tp->size + dsize;
1875 size = ALIGN(__size + sizeof(u32), sizeof(u64));
1876 size -= sizeof(u32);
1877 if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
1878 "profile buffer not large enough"))
1879 return;
1880
1881 entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx);
1882 if (!entry)
1883 return;
1884
1885 entry->func = (unsigned long)tp->rp.kp.addr;
1886 entry->ret_ip = (unsigned long)ri->ret_addr;
1887 store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize);
1888
1889 head = this_cpu_ptr(call->perf_events);
1890 perf_trace_buf_submit(entry, size, rctx, entry->ret_ip, 1, regs, head);
1891 }
1892 #endif /* CONFIG_PERF_EVENTS */
1893
1894 static __kprobes
1895 int kprobe_register(struct ftrace_event_call *event,
1896 enum trace_reg type, void *data)
1897 {
1898 struct trace_probe *tp = (struct trace_probe *)event->data;
1899
1900 switch (type) {
1901 case TRACE_REG_REGISTER:
1902 return enable_trace_probe(tp, TP_FLAG_TRACE);
1903 case TRACE_REG_UNREGISTER:
1904 disable_trace_probe(tp, TP_FLAG_TRACE);
1905 return 0;
1906
1907 #ifdef CONFIG_PERF_EVENTS
1908 case TRACE_REG_PERF_REGISTER:
1909 return enable_trace_probe(tp, TP_FLAG_PROFILE);
1910 case TRACE_REG_PERF_UNREGISTER:
1911 disable_trace_probe(tp, TP_FLAG_PROFILE);
1912 return 0;
1913 case TRACE_REG_PERF_OPEN:
1914 case TRACE_REG_PERF_CLOSE:
1915 case TRACE_REG_PERF_ADD:
1916 case TRACE_REG_PERF_DEL:
1917 return 0;
1918 #endif
1919 }
1920 return 0;
1921 }
1922
1923 static __kprobes
1924 int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs)
1925 {
1926 struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
1927
1928 if (tp->flags & TP_FLAG_TRACE)
1929 kprobe_trace_func(kp, regs);
1930 #ifdef CONFIG_PERF_EVENTS
1931 if (tp->flags & TP_FLAG_PROFILE)
1932 kprobe_perf_func(kp, regs);
1933 #endif
1934 return 0; /* We don't tweek kernel, so just return 0 */
1935 }
1936
1937 static __kprobes
1938 int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs)
1939 {
1940 struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
1941
1942 if (tp->flags & TP_FLAG_TRACE)
1943 kretprobe_trace_func(ri, regs);
1944 #ifdef CONFIG_PERF_EVENTS
1945 if (tp->flags & TP_FLAG_PROFILE)
1946 kretprobe_perf_func(ri, regs);
1947 #endif
1948 return 0; /* We don't tweek kernel, so just return 0 */
1949 }
1950
1951 static struct trace_event_functions kretprobe_funcs = {
1952 .trace = print_kretprobe_event
1953 };
1954
1955 static struct trace_event_functions kprobe_funcs = {
1956 .trace = print_kprobe_event
1957 };
1958
1959 static int register_probe_event(struct trace_probe *tp)
1960 {
1961 struct ftrace_event_call *call = &tp->call;
1962 int ret;
1963
1964 /* Initialize ftrace_event_call */
1965 INIT_LIST_HEAD(&call->class->fields);
1966 if (trace_probe_is_return(tp)) {
1967 call->event.funcs = &kretprobe_funcs;
1968 call->class->define_fields = kretprobe_event_define_fields;
1969 } else {
1970 call->event.funcs = &kprobe_funcs;
1971 call->class->define_fields = kprobe_event_define_fields;
1972 }
1973 if (set_print_fmt(tp) < 0)
1974 return -ENOMEM;
1975 ret = register_ftrace_event(&call->event);
1976 if (!ret) {
1977 kfree(call->print_fmt);
1978 return -ENODEV;
1979 }
1980 call->flags = 0;
1981 call->class->reg = kprobe_register;
1982 call->data = tp;
1983 ret = trace_add_event_call(call);
1984 if (ret) {
1985 pr_info("Failed to register kprobe event: %s\n", call->name);
1986 kfree(call->print_fmt);
1987 unregister_ftrace_event(&call->event);
1988 }
1989 return ret;
1990 }
1991
1992 static void unregister_probe_event(struct trace_probe *tp)
1993 {
1994 /* tp->event is unregistered in trace_remove_event_call() */
1995 trace_remove_event_call(&tp->call);
1996 kfree(tp->call.print_fmt);
1997 }
1998
1999 /* Make a debugfs interface for controlling probe points */
2000 static __init int init_kprobe_trace(void)
2001 {
2002 struct dentry *d_tracer;
2003 struct dentry *entry;
2004
2005 if (register_module_notifier(&trace_probe_module_nb))
2006 return -EINVAL;
2007
2008 d_tracer = tracing_init_dentry();
2009 if (!d_tracer)
2010 return 0;
2011
2012 entry = debugfs_create_file("kprobe_events", 0644, d_tracer,
2013 NULL, &kprobe_events_ops);
2014
2015 /* Event list interface */
2016 if (!entry)
2017 pr_warning("Could not create debugfs "
2018 "'kprobe_events' entry\n");
2019
2020 /* Profile interface */
2021 entry = debugfs_create_file("kprobe_profile", 0444, d_tracer,
2022 NULL, &kprobe_profile_ops);
2023
2024 if (!entry)
2025 pr_warning("Could not create debugfs "
2026 "'kprobe_profile' entry\n");
2027 return 0;
2028 }
2029 fs_initcall(init_kprobe_trace);
2030
2031
2032 #ifdef CONFIG_FTRACE_STARTUP_TEST
2033
2034 /*
2035 * The "__used" keeps gcc from removing the function symbol
2036 * from the kallsyms table.
2037 */
2038 static __used int kprobe_trace_selftest_target(int a1, int a2, int a3,
2039 int a4, int a5, int a6)
2040 {
2041 return a1 + a2 + a3 + a4 + a5 + a6;
2042 }
2043
2044 static __init int kprobe_trace_self_tests_init(void)
2045 {
2046 int ret, warn = 0;
2047 int (*target)(int, int, int, int, int, int);
2048 struct trace_probe *tp;
2049
2050 target = kprobe_trace_selftest_target;
2051
2052 pr_info("Testing kprobe tracing: ");
2053
2054 ret = command_trace_probe("p:testprobe kprobe_trace_selftest_target "
2055 "$stack $stack0 +0($stack)");
2056 if (WARN_ON_ONCE(ret)) {
2057 pr_warning("error on probing function entry.\n");
2058 warn++;
2059 } else {
2060 /* Enable trace point */
2061 tp = find_trace_probe("testprobe", KPROBE_EVENT_SYSTEM);
2062 if (WARN_ON_ONCE(tp == NULL)) {
2063 pr_warning("error on getting new probe.\n");
2064 warn++;
2065 } else
2066 enable_trace_probe(tp, TP_FLAG_TRACE);
2067 }
2068
2069 ret = command_trace_probe("r:testprobe2 kprobe_trace_selftest_target "
2070 "$retval");
2071 if (WARN_ON_ONCE(ret)) {
2072 pr_warning("error on probing function return.\n");
2073 warn++;
2074 } else {
2075 /* Enable trace point */
2076 tp = find_trace_probe("testprobe2", KPROBE_EVENT_SYSTEM);
2077 if (WARN_ON_ONCE(tp == NULL)) {
2078 pr_warning("error on getting new probe.\n");
2079 warn++;
2080 } else
2081 enable_trace_probe(tp, TP_FLAG_TRACE);
2082 }
2083
2084 if (warn)
2085 goto end;
2086
2087 ret = target(1, 2, 3, 4, 5, 6);
2088
2089 /* Disable trace points before removing it */
2090 tp = find_trace_probe("testprobe", KPROBE_EVENT_SYSTEM);
2091 if (WARN_ON_ONCE(tp == NULL)) {
2092 pr_warning("error on getting test probe.\n");
2093 warn++;
2094 } else
2095 disable_trace_probe(tp, TP_FLAG_TRACE);
2096
2097 tp = find_trace_probe("testprobe2", KPROBE_EVENT_SYSTEM);
2098 if (WARN_ON_ONCE(tp == NULL)) {
2099 pr_warning("error on getting 2nd test probe.\n");
2100 warn++;
2101 } else
2102 disable_trace_probe(tp, TP_FLAG_TRACE);
2103
2104 ret = command_trace_probe("-:testprobe");
2105 if (WARN_ON_ONCE(ret)) {
2106 pr_warning("error on deleting a probe.\n");
2107 warn++;
2108 }
2109
2110 ret = command_trace_probe("-:testprobe2");
2111 if (WARN_ON_ONCE(ret)) {
2112 pr_warning("error on deleting a probe.\n");
2113 warn++;
2114 }
2115
2116 end:
2117 release_all_trace_probes();
2118 if (warn)
2119 pr_cont("NG: Some tests are failed. Please check them.\n");
2120 else
2121 pr_cont("OK\n");
2122 return 0;
2123 }
2124
2125 late_initcall(kprobe_trace_self_tests_init);
2126
2127 #endif
Linus' kernel tree