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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
46#define FIELD_STRING_IP "__probe_ip"
47#define FIELD_STRING_RETIP "__probe_ret_ip"
48#define FIELD_STRING_FUNC "__probe_func"
49
50const 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
62typedef 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
68#define DEFINE_BASIC_PRINT_TYPE_FUNC(type, fmt, cast) \
69static __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} \
75static const char PRINT_TYPE_FMT_NAME(type)[] = fmt;
76
77DEFINE_BASIC_PRINT_TYPE_FUNC(u8, "%x", unsigned int)
78DEFINE_BASIC_PRINT_TYPE_FUNC(u16, "%x", unsigned int)
79DEFINE_BASIC_PRINT_TYPE_FUNC(u32, "%lx", unsigned long)
80DEFINE_BASIC_PRINT_TYPE_FUNC(u64, "%llx", unsigned long long)
81DEFINE_BASIC_PRINT_TYPE_FUNC(s8, "%d", int)
82DEFINE_BASIC_PRINT_TYPE_FUNC(s16, "%d", int)
83DEFINE_BASIC_PRINT_TYPE_FUNC(s32, "%ld", long)
84DEFINE_BASIC_PRINT_TYPE_FUNC(s64, "%lld", long long)
85
86
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
92static inline void *get_rloc_data(u32 *dl)
93{
94 return (u8 *)dl + get_rloc_offs(*dl);
95}
96
97
98static inline void *get_loc_data(u32 *dl, void *ent)
99{
100 return (u8 *)ent + get_rloc_offs(*dl);
101}
102
103
104
105
106
107
108#define convert_rloc_to_loc(dl, offs) ((u32)(dl) + (offs))
109
110
111typedef u32 string;
112typedef u32 string_size;
113
114
115static __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}
127static const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\"";
128
129
130typedef void (*fetch_func_t)(struct pt_regs *, void *, void *);
131
132struct fetch_param {
133 fetch_func_t fn;
134 void *data;
135};
136
137static __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
146
147
148#define DEFINE_BASIC_FETCH_FUNCS(method) \
149DEFINE_FETCH_##method(u8) \
150DEFINE_FETCH_##method(u16) \
151DEFINE_FETCH_##method(u32) \
152DEFINE_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
164#define DEFINE_FETCH_reg(type) \
165static __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}
171DEFINE_BASIC_FETCH_FUNCS(reg)
172
173#define fetch_reg_string NULL
174#define fetch_reg_string_size NULL
175
176#define DEFINE_FETCH_stack(type) \
177static __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}
183DEFINE_BASIC_FETCH_FUNCS(stack)
184
185#define fetch_stack_string NULL
186#define fetch_stack_string_size NULL
187
188#define DEFINE_FETCH_retval(type) \
189static __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}
194DEFINE_BASIC_FETCH_FUNCS(retval)
195
196#define fetch_retval_string NULL
197#define fetch_retval_string_size NULL
198
199#define DEFINE_FETCH_memory(type) \
200static __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}
209DEFINE_BASIC_FETCH_FUNCS(memory)
210
211
212
213
214static __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
226
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) {
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
245static __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)
262 *(u32 *)dest = 0;
263 else
264 *(u32 *)dest = len;
265}
266
267
268struct symbol_cache {
269 char *symbol;
270 long offset;
271 unsigned long addr;
272};
273
274static 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
282static void free_symbol_cache(struct symbol_cache *sc)
283{
284 kfree(sc->symbol);
285 kfree(sc);
286}
287
288static 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) \
310static __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}
319DEFINE_BASIC_FETCH_FUNCS(symbol)
320DEFINE_FETCH_symbol(string)
321DEFINE_FETCH_symbol(string_size)
322
323
324struct deref_fetch_param {
325 struct fetch_param orig;
326 long offset;
327};
328
329#define DEFINE_FETCH_deref(type) \
330static __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}
342DEFINE_BASIC_FETCH_FUNCS(deref)
343DEFINE_FETCH_deref(string)
344DEFINE_FETCH_deref(string_size)
345
346static __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
354static __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
364struct 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) \
371static __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}
383DEFINE_BASIC_FETCH_FUNCS(bitfield)
384#define fetch_bitfield_string NULL
385#define fetch_bitfield_string_size NULL
386
387static __kprobes void
388update_bitfield_fetch_param(struct bitfield_fetch_param *data)
389{
390
391
392
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
400static __kprobes void
401free_bitfield_fetch_param(struct bitfield_fetch_param *data)
402{
403
404
405
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
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
421enum {
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 = { \
443ASSIGN_FETCH_FUNC(reg, ftype), \
444ASSIGN_FETCH_FUNC(stack, ftype), \
445ASSIGN_FETCH_FUNC(retval, ftype), \
446ASSIGN_FETCH_FUNC(memory, ftype), \
447ASSIGN_FETCH_FUNC(symbol, ftype), \
448ASSIGN_FETCH_FUNC(deref, ftype), \
449ASSIGN_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
460static const struct fetch_type {
461 const char *name;
462 size_t size;
463 int is_signed;
464 print_type_func_t print;
465 const char *fmt;
466 const char *fmttype;
467
468 fetch_func_t fetch[FETCH_MTD_END];
469} fetch_type_table[] = {
470
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
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
486static 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
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];
519fail:
520 return NULL;
521}
522
523
524static __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
530static 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;
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);
542 return NULL;
543}
544
545
546
547
548
549struct probe_arg {
550 struct fetch_param fetch;
551 struct fetch_param fetch_size;
552 unsigned int offset;
553 const char *name;
554 const char *comm;
555 const struct fetch_type *type;
556};
557
558
559#define TP_FLAG_TRACE 1
560#define TP_FLAG_PROFILE 2
561#define TP_FLAG_REGISTERED 4
562
563struct trace_probe {
564 struct list_head list;
565 struct kretprobe rp;
566 unsigned long nhit;
567 unsigned int flags;
568 const char *symbol;
569 struct ftrace_event_class class;
570 struct ftrace_event_call call;
571 ssize_t 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
581static __kprobes int trace_probe_is_return(struct trace_probe *tp)
582{
583 return tp->rp.handler != NULL;
584}
585
586static __kprobes const char *trace_probe_symbol(struct trace_probe *tp)
587{
588 return tp->symbol ? tp->symbol : "unknown";
589}
590
591static __kprobes unsigned long trace_probe_offset(struct trace_probe *tp)
592{
593 return tp->rp.kp.offset;
594}
595
596static __kprobes bool trace_probe_is_enabled(struct trace_probe *tp)
597{
598 return !!(tp->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE));
599}
600
601static __kprobes bool trace_probe_is_registered(struct trace_probe *tp)
602{
603 return !!(tp->flags & TP_FLAG_REGISTERED);
604}
605
606static __kprobes bool trace_probe_has_gone(struct trace_probe *tp)
607{
608 return !!(kprobe_gone(&tp->rp.kp));
609}
610
611static __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
619static __kprobes bool trace_probe_is_on_module(struct trace_probe *tp)
620{
621 return !!strchr(trace_probe_symbol(tp), ':');
622}
623
624static int register_probe_event(struct trace_probe *tp);
625static void unregister_probe_event(struct trace_probe *tp);
626
627static DEFINE_MUTEX(probe_lock);
628static LIST_HEAD(probe_list);
629
630static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs);
631static int kretprobe_dispatcher(struct kretprobe_instance *ri,
632 struct pt_regs *regs);
633
634
635static 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
648
649static 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;
698error:
699 kfree(tp->call.name);
700 kfree(tp->symbol);
701 kfree(tp);
702 return ERR_PTR(ret);
703}
704
705static 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
715static 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
727static 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
740static 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
753static 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
770static 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
782static 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
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
824static 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
833 if (tp->rp.kp.symbol_name)
834 tp->rp.kp.addr = NULL;
835 }
836}
837
838
839static int unregister_trace_probe(struct trace_probe *tp)
840{
841
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
853static 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
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
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
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
883end:
884 mutex_unlock(&probe_lock);
885 return ret;
886}
887
888
889static 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
900 mutex_lock(&probe_lock);
901 list_for_each_entry(tp, &probe_list, list) {
902 if (trace_probe_within_module(tp, mod)) {
903
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
917static struct notifier_block trace_probe_module_nb = {
918 .notifier_call = trace_probe_module_callback,
919 .priority = 1
920};
921
922
923static 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
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
946static 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, ¶m);
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
979static 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 '%':
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 '@':
1000 if (isdigit(arg[1])) {
1001 ret = strict_strtoul(arg + 1, 0, ¶m);
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 '+':
1016 arg++;
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) {
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
1058static 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);
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
1091static 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
1130static 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
1143static int create_trace_probe(int argc, char **argv)
1144{
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
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
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
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
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
1241 symbol = argv[1];
1242
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
1256 if (!event) {
1257
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
1275 ret = 0;
1276 for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
1277
1278 tp->nr_args++;
1279
1280
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
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
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
1325error:
1326 free_trace_probe(tp);
1327 return ret;
1328}
1329
1330static int release_all_trace_probes(void)
1331{
1332 struct trace_probe *tp;
1333 int ret = 0;
1334
1335 mutex_lock(&probe_lock);
1336
1337 list_for_each_entry(tp, &probe_list, list)
1338 if (trace_probe_is_enabled(tp)) {
1339 ret = -EBUSY;
1340 goto end;
1341 }
1342
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
1349end:
1350 mutex_unlock(&probe_lock);
1351
1352 return ret;
1353}
1354
1355
1356static 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
1362static 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
1367static void probes_seq_stop(struct seq_file *m, void *v)
1368{
1369 mutex_unlock(&probe_lock);
1370}
1371
1372static 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
1395static 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
1402static 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
1415static 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
1433static 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
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;
1476out:
1477 kfree(kbuf);
1478 return ret;
1479}
1480
1481static 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
1491static 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
1501static 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
1508static int profile_open(struct inode *inode, struct file *file)
1509{
1510 return seq_open(file, &profile_seq_op);
1511}
1512
1513static 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
1522static __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
1538static __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;
1545
1546 for (i = 0; i < tp->nr_args; i++) {
1547 if (unlikely(tp->args[i].fetch_size.fn)) {
1548
1549
1550
1551
1552 dl = (u32 *)(data + tp->args[i].offset);
1553 *dl = make_data_rloc(maxlen, end - tp->args[i].offset);
1554
1555 call_fetch(&tp->args[i].fetch, regs, dl);
1556
1557 end += get_rloc_len(*dl);
1558 maxlen -= get_rloc_len(*dl);
1559
1560 *dl = convert_rloc_to_loc(*dl,
1561 ent_size + tp->args[i].offset);
1562 } else
1563
1564 call_fetch(&tp->args[i].fetch, regs,
1565 data + tp->args[i].offset);
1566 }
1567}
1568
1569
1570static __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
1603static __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
1636enum print_line_t
1637print_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;
1668partial:
1669 return TRACE_TYPE_PARTIAL_LINE;
1670}
1671
1672enum print_line_t
1673print_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;
1710partial:
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
1725static 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
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
1746static 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
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
1768static 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
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
1808 return pos;
1809}
1810
1811static int set_print_fmt(struct trace_probe *tp)
1812{
1813 int len;
1814 char *print_fmt;
1815
1816
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
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
1832static __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
1863static __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
1893
1894static __kprobes
1895int kprobe_register(struct ftrace_event_call *event, enum trace_reg type)
1896{
1897 struct trace_probe *tp = (struct trace_probe *)event->data;
1898
1899 switch (type) {
1900 case TRACE_REG_REGISTER:
1901 return enable_trace_probe(tp, TP_FLAG_TRACE);
1902 case TRACE_REG_UNREGISTER:
1903 disable_trace_probe(tp, TP_FLAG_TRACE);
1904 return 0;
1905
1906#ifdef CONFIG_PERF_EVENTS
1907 case TRACE_REG_PERF_REGISTER:
1908 return enable_trace_probe(tp, TP_FLAG_PROFILE);
1909 case TRACE_REG_PERF_UNREGISTER:
1910 disable_trace_probe(tp, TP_FLAG_PROFILE);
1911 return 0;
1912#endif
1913 }
1914 return 0;
1915}
1916
1917static __kprobes
1918int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs)
1919{
1920 struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
1921
1922 if (tp->flags & TP_FLAG_TRACE)
1923 kprobe_trace_func(kp, regs);
1924#ifdef CONFIG_PERF_EVENTS
1925 if (tp->flags & TP_FLAG_PROFILE)
1926 kprobe_perf_func(kp, regs);
1927#endif
1928 return 0;
1929}
1930
1931static __kprobes
1932int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs)
1933{
1934 struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
1935
1936 if (tp->flags & TP_FLAG_TRACE)
1937 kretprobe_trace_func(ri, regs);
1938#ifdef CONFIG_PERF_EVENTS
1939 if (tp->flags & TP_FLAG_PROFILE)
1940 kretprobe_perf_func(ri, regs);
1941#endif
1942 return 0;
1943}
1944
1945static struct trace_event_functions kretprobe_funcs = {
1946 .trace = print_kretprobe_event
1947};
1948
1949static struct trace_event_functions kprobe_funcs = {
1950 .trace = print_kprobe_event
1951};
1952
1953static int register_probe_event(struct trace_probe *tp)
1954{
1955 struct ftrace_event_call *call = &tp->call;
1956 int ret;
1957
1958
1959 INIT_LIST_HEAD(&call->class->fields);
1960 if (trace_probe_is_return(tp)) {
1961 call->event.funcs = &kretprobe_funcs;
1962 call->class->define_fields = kretprobe_event_define_fields;
1963 } else {
1964 call->event.funcs = &kprobe_funcs;
1965 call->class->define_fields = kprobe_event_define_fields;
1966 }
1967 if (set_print_fmt(tp) < 0)
1968 return -ENOMEM;
1969 ret = register_ftrace_event(&call->event);
1970 if (!ret) {
1971 kfree(call->print_fmt);
1972 return -ENODEV;
1973 }
1974 call->flags = 0;
1975 call->class->reg = kprobe_register;
1976 call->data = tp;
1977 ret = trace_add_event_call(call);
1978 if (ret) {
1979 pr_info("Failed to register kprobe event: %s\n", call->name);
1980 kfree(call->print_fmt);
1981 unregister_ftrace_event(&call->event);
1982 }
1983 return ret;
1984}
1985
1986static void unregister_probe_event(struct trace_probe *tp)
1987{
1988
1989 trace_remove_event_call(&tp->call);
1990 kfree(tp->call.print_fmt);
1991}
1992
1993
1994static __init int init_kprobe_trace(void)
1995{
1996 struct dentry *d_tracer;
1997 struct dentry *entry;
1998
1999 if (register_module_notifier(&trace_probe_module_nb))
2000 return -EINVAL;
2001
2002 d_tracer = tracing_init_dentry();
2003 if (!d_tracer)
2004 return 0;
2005
2006 entry = debugfs_create_file("kprobe_events", 0644, d_tracer,
2007 NULL, &kprobe_events_ops);
2008
2009
2010 if (!entry)
2011 pr_warning("Could not create debugfs "
2012 "'kprobe_events' entry\n");
2013
2014
2015 entry = debugfs_create_file("kprobe_profile", 0444, d_tracer,
2016 NULL, &kprobe_profile_ops);
2017
2018 if (!entry)
2019 pr_warning("Could not create debugfs "
2020 "'kprobe_profile' entry\n");
2021 return 0;
2022}
2023fs_initcall(init_kprobe_trace);
2024
2025
2026#ifdef CONFIG_FTRACE_STARTUP_TEST
2027
2028
2029
2030
2031
2032static __used int kprobe_trace_selftest_target(int a1, int a2, int a3,
2033 int a4, int a5, int a6)
2034{
2035 return a1 + a2 + a3 + a4 + a5 + a6;
2036}
2037
2038static __init int kprobe_trace_self_tests_init(void)
2039{
2040 int ret, warn = 0;
2041 int (*target)(int, int, int, int, int, int);
2042 struct trace_probe *tp;
2043
2044 target = kprobe_trace_selftest_target;
2045
2046 pr_info("Testing kprobe tracing: ");
2047
2048 ret = command_trace_probe("p:testprobe kprobe_trace_selftest_target "
2049 "$stack $stack0 +0($stack)");
2050 if (WARN_ON_ONCE(ret)) {
2051 pr_warning("error on probing function entry.\n");
2052 warn++;
2053 } else {
2054
2055 tp = find_trace_probe("testprobe", KPROBE_EVENT_SYSTEM);
2056 if (WARN_ON_ONCE(tp == NULL)) {
2057 pr_warning("error on getting new probe.\n");
2058 warn++;
2059 } else
2060 enable_trace_probe(tp, TP_FLAG_TRACE);
2061 }
2062
2063 ret = command_trace_probe("r:testprobe2 kprobe_trace_selftest_target "
2064 "$retval");
2065 if (WARN_ON_ONCE(ret)) {
2066 pr_warning("error on probing function return.\n");
2067 warn++;
2068 } else {
2069
2070 tp = find_trace_probe("testprobe2", KPROBE_EVENT_SYSTEM);
2071 if (WARN_ON_ONCE(tp == NULL)) {
2072 pr_warning("error on getting new probe.\n");
2073 warn++;
2074 } else
2075 enable_trace_probe(tp, TP_FLAG_TRACE);
2076 }
2077
2078 if (warn)
2079 goto end;
2080
2081 ret = target(1, 2, 3, 4, 5, 6);
2082
2083
2084 tp = find_trace_probe("testprobe", KPROBE_EVENT_SYSTEM);
2085 if (WARN_ON_ONCE(tp == NULL)) {
2086 pr_warning("error on getting test probe.\n");
2087 warn++;
2088 } else
2089 disable_trace_probe(tp, TP_FLAG_TRACE);
2090
2091 tp = find_trace_probe("testprobe2", KPROBE_EVENT_SYSTEM);
2092 if (WARN_ON_ONCE(tp == NULL)) {
2093 pr_warning("error on getting 2nd test probe.\n");
2094 warn++;
2095 } else
2096 disable_trace_probe(tp, TP_FLAG_TRACE);
2097
2098 ret = command_trace_probe("-:testprobe");
2099 if (WARN_ON_ONCE(ret)) {
2100 pr_warning("error on deleting a probe.\n");
2101 warn++;
2102 }
2103
2104 ret = command_trace_probe("-:testprobe2");
2105 if (WARN_ON_ONCE(ret)) {
2106 pr_warning("error on deleting a probe.\n");
2107 warn++;
2108 }
2109
2110end:
2111 release_all_trace_probes();
2112 if (warn)
2113 pr_cont("NG: Some tests are failed. Please check them.\n");
2114 else
2115 pr_cont("OK\n");
2116 return 0;
2117}
2118
2119late_initcall(kprobe_trace_self_tests_init);
2120
2121#endif
2122
