Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[sfrench/cifs-2.6.git] / kernel / trace / trace_kprobe.c
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
33 #include "trace.h"
34 #include "trace_output.h"
35
36 #define MAX_TRACE_ARGS 128
37 #define MAX_ARGSTR_LEN 63
38 #define MAX_EVENT_NAME_LEN 64
39 #define KPROBE_EVENT_SYSTEM "kprobes"
40
41 /* Reserved field names */
42 #define FIELD_STRING_IP "__probe_ip"
43 #define FIELD_STRING_NARGS "__probe_nargs"
44 #define FIELD_STRING_RETIP "__probe_ret_ip"
45 #define FIELD_STRING_FUNC "__probe_func"
46
47 const char *reserved_field_names[] = {
48         "common_type",
49         "common_flags",
50         "common_preempt_count",
51         "common_pid",
52         "common_tgid",
53         "common_lock_depth",
54         FIELD_STRING_IP,
55         FIELD_STRING_NARGS,
56         FIELD_STRING_RETIP,
57         FIELD_STRING_FUNC,
58 };
59
60 struct fetch_func {
61         unsigned long (*func)(struct pt_regs *, void *);
62         void *data;
63 };
64
65 static __kprobes unsigned long call_fetch(struct fetch_func *f,
66                                           struct pt_regs *regs)
67 {
68         return f->func(regs, f->data);
69 }
70
71 /* fetch handlers */
72 static __kprobes unsigned long fetch_register(struct pt_regs *regs,
73                                               void *offset)
74 {
75         return regs_get_register(regs, (unsigned int)((unsigned long)offset));
76 }
77
78 static __kprobes unsigned long fetch_stack(struct pt_regs *regs,
79                                            void *num)
80 {
81         return regs_get_kernel_stack_nth(regs,
82                                          (unsigned int)((unsigned long)num));
83 }
84
85 static __kprobes unsigned long fetch_memory(struct pt_regs *regs, void *addr)
86 {
87         unsigned long retval;
88
89         if (probe_kernel_address(addr, retval))
90                 return 0;
91         return retval;
92 }
93
94 static __kprobes unsigned long fetch_argument(struct pt_regs *regs, void *num)
95 {
96         return regs_get_argument_nth(regs, (unsigned int)((unsigned long)num));
97 }
98
99 static __kprobes unsigned long fetch_retvalue(struct pt_regs *regs,
100                                               void *dummy)
101 {
102         return regs_return_value(regs);
103 }
104
105 static __kprobes unsigned long fetch_stack_address(struct pt_regs *regs,
106                                                    void *dummy)
107 {
108         return kernel_stack_pointer(regs);
109 }
110
111 /* Memory fetching by symbol */
112 struct symbol_cache {
113         char *symbol;
114         long offset;
115         unsigned long addr;
116 };
117
118 static unsigned long update_symbol_cache(struct symbol_cache *sc)
119 {
120         sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol);
121         if (sc->addr)
122                 sc->addr += sc->offset;
123         return sc->addr;
124 }
125
126 static void free_symbol_cache(struct symbol_cache *sc)
127 {
128         kfree(sc->symbol);
129         kfree(sc);
130 }
131
132 static struct symbol_cache *alloc_symbol_cache(const char *sym, long offset)
133 {
134         struct symbol_cache *sc;
135
136         if (!sym || strlen(sym) == 0)
137                 return NULL;
138         sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL);
139         if (!sc)
140                 return NULL;
141
142         sc->symbol = kstrdup(sym, GFP_KERNEL);
143         if (!sc->symbol) {
144                 kfree(sc);
145                 return NULL;
146         }
147         sc->offset = offset;
148
149         update_symbol_cache(sc);
150         return sc;
151 }
152
153 static __kprobes unsigned long fetch_symbol(struct pt_regs *regs, void *data)
154 {
155         struct symbol_cache *sc = data;
156
157         if (sc->addr)
158                 return fetch_memory(regs, (void *)sc->addr);
159         else
160                 return 0;
161 }
162
163 /* Special indirect memory access interface */
164 struct indirect_fetch_data {
165         struct fetch_func orig;
166         long offset;
167 };
168
169 static __kprobes unsigned long fetch_indirect(struct pt_regs *regs, void *data)
170 {
171         struct indirect_fetch_data *ind = data;
172         unsigned long addr;
173
174         addr = call_fetch(&ind->orig, regs);
175         if (addr) {
176                 addr += ind->offset;
177                 return fetch_memory(regs, (void *)addr);
178         } else
179                 return 0;
180 }
181
182 static __kprobes void free_indirect_fetch_data(struct indirect_fetch_data *data)
183 {
184         if (data->orig.func == fetch_indirect)
185                 free_indirect_fetch_data(data->orig.data);
186         else if (data->orig.func == fetch_symbol)
187                 free_symbol_cache(data->orig.data);
188         kfree(data);
189 }
190
191 /**
192  * Kprobe event core functions
193  */
194
195 struct probe_arg {
196         struct fetch_func       fetch;
197         const char              *name;
198 };
199
200 /* Flags for trace_probe */
201 #define TP_FLAG_TRACE   1
202 #define TP_FLAG_PROFILE 2
203
204 struct trace_probe {
205         struct list_head        list;
206         struct kretprobe        rp;     /* Use rp.kp for kprobe use */
207         unsigned long           nhit;
208         unsigned int            flags;  /* For TP_FLAG_* */
209         const char              *symbol;        /* symbol name */
210         struct ftrace_event_call        call;
211         struct trace_event              event;
212         unsigned int            nr_args;
213         struct probe_arg        args[];
214 };
215
216 #define SIZEOF_TRACE_PROBE(n)                   \
217         (offsetof(struct trace_probe, args) +   \
218         (sizeof(struct probe_arg) * (n)))
219
220 static __kprobes int probe_is_return(struct trace_probe *tp)
221 {
222         return tp->rp.handler != NULL;
223 }
224
225 static __kprobes const char *probe_symbol(struct trace_probe *tp)
226 {
227         return tp->symbol ? tp->symbol : "unknown";
228 }
229
230 static int probe_arg_string(char *buf, size_t n, struct fetch_func *ff)
231 {
232         int ret = -EINVAL;
233
234         if (ff->func == fetch_argument)
235                 ret = snprintf(buf, n, "$arg%lu", (unsigned long)ff->data);
236         else if (ff->func == fetch_register) {
237                 const char *name;
238                 name = regs_query_register_name((unsigned int)((long)ff->data));
239                 ret = snprintf(buf, n, "%%%s", name);
240         } else if (ff->func == fetch_stack)
241                 ret = snprintf(buf, n, "$stack%lu", (unsigned long)ff->data);
242         else if (ff->func == fetch_memory)
243                 ret = snprintf(buf, n, "@0x%p", ff->data);
244         else if (ff->func == fetch_symbol) {
245                 struct symbol_cache *sc = ff->data;
246                 if (sc->offset)
247                         ret = snprintf(buf, n, "@%s%+ld", sc->symbol,
248                                         sc->offset);
249                 else
250                         ret = snprintf(buf, n, "@%s", sc->symbol);
251         } else if (ff->func == fetch_retvalue)
252                 ret = snprintf(buf, n, "$retval");
253         else if (ff->func == fetch_stack_address)
254                 ret = snprintf(buf, n, "$stack");
255         else if (ff->func == fetch_indirect) {
256                 struct indirect_fetch_data *id = ff->data;
257                 size_t l = 0;
258                 ret = snprintf(buf, n, "%+ld(", id->offset);
259                 if (ret >= n)
260                         goto end;
261                 l += ret;
262                 ret = probe_arg_string(buf + l, n - l, &id->orig);
263                 if (ret < 0)
264                         goto end;
265                 l += ret;
266                 ret = snprintf(buf + l, n - l, ")");
267                 ret += l;
268         }
269 end:
270         if (ret >= n)
271                 return -ENOSPC;
272         return ret;
273 }
274
275 static int register_probe_event(struct trace_probe *tp);
276 static void unregister_probe_event(struct trace_probe *tp);
277
278 static DEFINE_MUTEX(probe_lock);
279 static LIST_HEAD(probe_list);
280
281 static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs);
282 static int kretprobe_dispatcher(struct kretprobe_instance *ri,
283                                 struct pt_regs *regs);
284
285 /* Check the name is good for event/group */
286 static int check_event_name(const char *name)
287 {
288         if (!isalpha(*name) && *name != '_')
289                 return 0;
290         while (*++name != '\0') {
291                 if (!isalpha(*name) && !isdigit(*name) && *name != '_')
292                         return 0;
293         }
294         return 1;
295 }
296
297 /*
298  * Allocate new trace_probe and initialize it (including kprobes).
299  */
300 static struct trace_probe *alloc_trace_probe(const char *group,
301                                              const char *event,
302                                              void *addr,
303                                              const char *symbol,
304                                              unsigned long offs,
305                                              int nargs, int is_return)
306 {
307         struct trace_probe *tp;
308         int ret = -ENOMEM;
309
310         tp = kzalloc(SIZEOF_TRACE_PROBE(nargs), GFP_KERNEL);
311         if (!tp)
312                 return ERR_PTR(ret);
313
314         if (symbol) {
315                 tp->symbol = kstrdup(symbol, GFP_KERNEL);
316                 if (!tp->symbol)
317                         goto error;
318                 tp->rp.kp.symbol_name = tp->symbol;
319                 tp->rp.kp.offset = offs;
320         } else
321                 tp->rp.kp.addr = addr;
322
323         if (is_return)
324                 tp->rp.handler = kretprobe_dispatcher;
325         else
326                 tp->rp.kp.pre_handler = kprobe_dispatcher;
327
328         if (!event || !check_event_name(event)) {
329                 ret = -EINVAL;
330                 goto error;
331         }
332
333         tp->call.name = kstrdup(event, GFP_KERNEL);
334         if (!tp->call.name)
335                 goto error;
336
337         if (!group || !check_event_name(group)) {
338                 ret = -EINVAL;
339                 goto error;
340         }
341
342         tp->call.system = kstrdup(group, GFP_KERNEL);
343         if (!tp->call.system)
344                 goto error;
345
346         INIT_LIST_HEAD(&tp->list);
347         return tp;
348 error:
349         kfree(tp->call.name);
350         kfree(tp->symbol);
351         kfree(tp);
352         return ERR_PTR(ret);
353 }
354
355 static void free_probe_arg(struct probe_arg *arg)
356 {
357         if (arg->fetch.func == fetch_symbol)
358                 free_symbol_cache(arg->fetch.data);
359         else if (arg->fetch.func == fetch_indirect)
360                 free_indirect_fetch_data(arg->fetch.data);
361         kfree(arg->name);
362 }
363
364 static void free_trace_probe(struct trace_probe *tp)
365 {
366         int i;
367
368         for (i = 0; i < tp->nr_args; i++)
369                 free_probe_arg(&tp->args[i]);
370
371         kfree(tp->call.system);
372         kfree(tp->call.name);
373         kfree(tp->symbol);
374         kfree(tp);
375 }
376
377 static struct trace_probe *find_probe_event(const char *event,
378                                             const char *group)
379 {
380         struct trace_probe *tp;
381
382         list_for_each_entry(tp, &probe_list, list)
383                 if (strcmp(tp->call.name, event) == 0 &&
384                     strcmp(tp->call.system, group) == 0)
385                         return tp;
386         return NULL;
387 }
388
389 /* Unregister a trace_probe and probe_event: call with locking probe_lock */
390 static void unregister_trace_probe(struct trace_probe *tp)
391 {
392         if (probe_is_return(tp))
393                 unregister_kretprobe(&tp->rp);
394         else
395                 unregister_kprobe(&tp->rp.kp);
396         list_del(&tp->list);
397         unregister_probe_event(tp);
398 }
399
400 /* Register a trace_probe and probe_event */
401 static int register_trace_probe(struct trace_probe *tp)
402 {
403         struct trace_probe *old_tp;
404         int ret;
405
406         mutex_lock(&probe_lock);
407
408         /* register as an event */
409         old_tp = find_probe_event(tp->call.name, tp->call.system);
410         if (old_tp) {
411                 /* delete old event */
412                 unregister_trace_probe(old_tp);
413                 free_trace_probe(old_tp);
414         }
415         ret = register_probe_event(tp);
416         if (ret) {
417                 pr_warning("Faild to register probe event(%d)\n", ret);
418                 goto end;
419         }
420
421         tp->rp.kp.flags |= KPROBE_FLAG_DISABLED;
422         if (probe_is_return(tp))
423                 ret = register_kretprobe(&tp->rp);
424         else
425                 ret = register_kprobe(&tp->rp.kp);
426
427         if (ret) {
428                 pr_warning("Could not insert probe(%d)\n", ret);
429                 if (ret == -EILSEQ) {
430                         pr_warning("Probing address(0x%p) is not an "
431                                    "instruction boundary.\n",
432                                    tp->rp.kp.addr);
433                         ret = -EINVAL;
434                 }
435                 unregister_probe_event(tp);
436         } else
437                 list_add_tail(&tp->list, &probe_list);
438 end:
439         mutex_unlock(&probe_lock);
440         return ret;
441 }
442
443 /* Split symbol and offset. */
444 static int split_symbol_offset(char *symbol, unsigned long *offset)
445 {
446         char *tmp;
447         int ret;
448
449         if (!offset)
450                 return -EINVAL;
451
452         tmp = strchr(symbol, '+');
453         if (tmp) {
454                 /* skip sign because strict_strtol doesn't accept '+' */
455                 ret = strict_strtoul(tmp + 1, 0, offset);
456                 if (ret)
457                         return ret;
458                 *tmp = '\0';
459         } else
460                 *offset = 0;
461         return 0;
462 }
463
464 #define PARAM_MAX_ARGS 16
465 #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
466
467 static int parse_probe_vars(char *arg, struct fetch_func *ff, int is_return)
468 {
469         int ret = 0;
470         unsigned long param;
471
472         if (strcmp(arg, "retval") == 0) {
473                 if (is_return) {
474                         ff->func = fetch_retvalue;
475                         ff->data = NULL;
476                 } else
477                         ret = -EINVAL;
478         } else if (strncmp(arg, "stack", 5) == 0) {
479                 if (arg[5] == '\0') {
480                         ff->func = fetch_stack_address;
481                         ff->data = NULL;
482                 } else if (isdigit(arg[5])) {
483                         ret = strict_strtoul(arg + 5, 10, &param);
484                         if (ret || param > PARAM_MAX_STACK)
485                                 ret = -EINVAL;
486                         else {
487                                 ff->func = fetch_stack;
488                                 ff->data = (void *)param;
489                         }
490                 } else
491                         ret = -EINVAL;
492         } else if (strncmp(arg, "arg", 3) == 0 && isdigit(arg[3])) {
493                 ret = strict_strtoul(arg + 3, 10, &param);
494                 if (ret || param > PARAM_MAX_ARGS)
495                         ret = -EINVAL;
496                 else {
497                         ff->func = fetch_argument;
498                         ff->data = (void *)param;
499                 }
500         } else
501                 ret = -EINVAL;
502         return ret;
503 }
504
505 /* Recursive argument parser */
506 static int __parse_probe_arg(char *arg, struct fetch_func *ff, int is_return)
507 {
508         int ret = 0;
509         unsigned long param;
510         long offset;
511         char *tmp;
512
513         switch (arg[0]) {
514         case '$':
515                 ret = parse_probe_vars(arg + 1, ff, is_return);
516                 break;
517         case '%':       /* named register */
518                 ret = regs_query_register_offset(arg + 1);
519                 if (ret >= 0) {
520                         ff->func = fetch_register;
521                         ff->data = (void *)(unsigned long)ret;
522                         ret = 0;
523                 }
524                 break;
525         case '@':       /* memory or symbol */
526                 if (isdigit(arg[1])) {
527                         ret = strict_strtoul(arg + 1, 0, &param);
528                         if (ret)
529                                 break;
530                         ff->func = fetch_memory;
531                         ff->data = (void *)param;
532                 } else {
533                         ret = split_symbol_offset(arg + 1, &offset);
534                         if (ret)
535                                 break;
536                         ff->data = alloc_symbol_cache(arg + 1, offset);
537                         if (ff->data)
538                                 ff->func = fetch_symbol;
539                         else
540                                 ret = -EINVAL;
541                 }
542                 break;
543         case '+':       /* indirect memory */
544         case '-':
545                 tmp = strchr(arg, '(');
546                 if (!tmp) {
547                         ret = -EINVAL;
548                         break;
549                 }
550                 *tmp = '\0';
551                 ret = strict_strtol(arg + 1, 0, &offset);
552                 if (ret)
553                         break;
554                 if (arg[0] == '-')
555                         offset = -offset;
556                 arg = tmp + 1;
557                 tmp = strrchr(arg, ')');
558                 if (tmp) {
559                         struct indirect_fetch_data *id;
560                         *tmp = '\0';
561                         id = kzalloc(sizeof(struct indirect_fetch_data),
562                                      GFP_KERNEL);
563                         if (!id)
564                                 return -ENOMEM;
565                         id->offset = offset;
566                         ret = __parse_probe_arg(arg, &id->orig, is_return);
567                         if (ret)
568                                 kfree(id);
569                         else {
570                                 ff->func = fetch_indirect;
571                                 ff->data = (void *)id;
572                         }
573                 } else
574                         ret = -EINVAL;
575                 break;
576         default:
577                 /* TODO: support custom handler */
578                 ret = -EINVAL;
579         }
580         return ret;
581 }
582
583 /* String length checking wrapper */
584 static int parse_probe_arg(char *arg, struct fetch_func *ff, int is_return)
585 {
586         if (strlen(arg) > MAX_ARGSTR_LEN) {
587                 pr_info("Argument is too long.: %s\n",  arg);
588                 return -ENOSPC;
589         }
590         return __parse_probe_arg(arg, ff, is_return);
591 }
592
593 /* Return 1 if name is reserved or already used by another argument */
594 static int conflict_field_name(const char *name,
595                                struct probe_arg *args, int narg)
596 {
597         int i;
598         for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++)
599                 if (strcmp(reserved_field_names[i], name) == 0)
600                         return 1;
601         for (i = 0; i < narg; i++)
602                 if (strcmp(args[i].name, name) == 0)
603                         return 1;
604         return 0;
605 }
606
607 static int create_trace_probe(int argc, char **argv)
608 {
609         /*
610          * Argument syntax:
611          *  - Add kprobe: p[:[GRP/]EVENT] KSYM[+OFFS]|KADDR [FETCHARGS]
612          *  - Add kretprobe: r[:[GRP/]EVENT] KSYM[+0] [FETCHARGS]
613          * Fetch args:
614          *  $argN       : fetch Nth of function argument. (N:0-)
615          *  $retval     : fetch return value
616          *  $stack      : fetch stack address
617          *  $stackN     : fetch Nth of stack (N:0-)
618          *  @ADDR       : fetch memory at ADDR (ADDR should be in kernel)
619          *  @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol)
620          *  %REG        : fetch register REG
621          * Indirect memory fetch:
622          *  +|-offs(ARG) : fetch memory at ARG +|- offs address.
623          * Alias name of args:
624          *  NAME=FETCHARG : set NAME as alias of FETCHARG.
625          */
626         struct trace_probe *tp;
627         int i, ret = 0;
628         int is_return = 0, is_delete = 0;
629         char *symbol = NULL, *event = NULL, *arg = NULL, *group = NULL;
630         unsigned long offset = 0;
631         void *addr = NULL;
632         char buf[MAX_EVENT_NAME_LEN];
633
634         /* argc must be >= 1 */
635         if (argv[0][0] == 'p')
636                 is_return = 0;
637         else if (argv[0][0] == 'r')
638                 is_return = 1;
639         else if (argv[0][0] == '-')
640                 is_delete = 1;
641         else {
642                 pr_info("Probe definition must be started with 'p', 'r' or"
643                         " '-'.\n");
644                 return -EINVAL;
645         }
646
647         if (argv[0][1] == ':') {
648                 event = &argv[0][2];
649                 if (strchr(event, '/')) {
650                         group = event;
651                         event = strchr(group, '/') + 1;
652                         event[-1] = '\0';
653                         if (strlen(group) == 0) {
654                                 pr_info("Group name is not specifiled\n");
655                                 return -EINVAL;
656                         }
657                 }
658                 if (strlen(event) == 0) {
659                         pr_info("Event name is not specifiled\n");
660                         return -EINVAL;
661                 }
662         }
663         if (!group)
664                 group = KPROBE_EVENT_SYSTEM;
665
666         if (is_delete) {
667                 if (!event) {
668                         pr_info("Delete command needs an event name.\n");
669                         return -EINVAL;
670                 }
671                 tp = find_probe_event(event, group);
672                 if (!tp) {
673                         pr_info("Event %s/%s doesn't exist.\n", group, event);
674                         return -ENOENT;
675                 }
676                 /* delete an event */
677                 unregister_trace_probe(tp);
678                 free_trace_probe(tp);
679                 return 0;
680         }
681
682         if (argc < 2) {
683                 pr_info("Probe point is not specified.\n");
684                 return -EINVAL;
685         }
686         if (isdigit(argv[1][0])) {
687                 if (is_return) {
688                         pr_info("Return probe point must be a symbol.\n");
689                         return -EINVAL;
690                 }
691                 /* an address specified */
692                 ret = strict_strtoul(&argv[0][2], 0, (unsigned long *)&addr);
693                 if (ret) {
694                         pr_info("Failed to parse address.\n");
695                         return ret;
696                 }
697         } else {
698                 /* a symbol specified */
699                 symbol = argv[1];
700                 /* TODO: support .init module functions */
701                 ret = split_symbol_offset(symbol, &offset);
702                 if (ret) {
703                         pr_info("Failed to parse symbol.\n");
704                         return ret;
705                 }
706                 if (offset && is_return) {
707                         pr_info("Return probe must be used without offset.\n");
708                         return -EINVAL;
709                 }
710         }
711         argc -= 2; argv += 2;
712
713         /* setup a probe */
714         if (!event) {
715                 /* Make a new event name */
716                 if (symbol)
717                         snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld",
718                                  is_return ? 'r' : 'p', symbol, offset);
719                 else
720                         snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p",
721                                  is_return ? 'r' : 'p', addr);
722                 event = buf;
723         }
724         tp = alloc_trace_probe(group, event, addr, symbol, offset, argc,
725                                is_return);
726         if (IS_ERR(tp)) {
727                 pr_info("Failed to allocate trace_probe.(%d)\n",
728                         (int)PTR_ERR(tp));
729                 return PTR_ERR(tp);
730         }
731
732         /* parse arguments */
733         ret = 0;
734         for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
735                 /* Parse argument name */
736                 arg = strchr(argv[i], '=');
737                 if (arg)
738                         *arg++ = '\0';
739                 else
740                         arg = argv[i];
741
742                 if (conflict_field_name(argv[i], tp->args, i)) {
743                         pr_info("Argument%d name '%s' conflicts with "
744                                 "another field.\n", i, argv[i]);
745                         ret = -EINVAL;
746                         goto error;
747                 }
748
749                 tp->args[i].name = kstrdup(argv[i], GFP_KERNEL);
750                 if (!tp->args[i].name) {
751                         pr_info("Failed to allocate argument%d name '%s'.\n",
752                                 i, argv[i]);
753                         ret = -ENOMEM;
754                         goto error;
755                 }
756
757                 /* Parse fetch argument */
758                 ret = parse_probe_arg(arg, &tp->args[i].fetch, is_return);
759                 if (ret) {
760                         pr_info("Parse error at argument%d. (%d)\n", i, ret);
761                         kfree(tp->args[i].name);
762                         goto error;
763                 }
764
765                 tp->nr_args++;
766         }
767
768         ret = register_trace_probe(tp);
769         if (ret)
770                 goto error;
771         return 0;
772
773 error:
774         free_trace_probe(tp);
775         return ret;
776 }
777
778 static void cleanup_all_probes(void)
779 {
780         struct trace_probe *tp;
781
782         mutex_lock(&probe_lock);
783         /* TODO: Use batch unregistration */
784         while (!list_empty(&probe_list)) {
785                 tp = list_entry(probe_list.next, struct trace_probe, list);
786                 unregister_trace_probe(tp);
787                 free_trace_probe(tp);
788         }
789         mutex_unlock(&probe_lock);
790 }
791
792
793 /* Probes listing interfaces */
794 static void *probes_seq_start(struct seq_file *m, loff_t *pos)
795 {
796         mutex_lock(&probe_lock);
797         return seq_list_start(&probe_list, *pos);
798 }
799
800 static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos)
801 {
802         return seq_list_next(v, &probe_list, pos);
803 }
804
805 static void probes_seq_stop(struct seq_file *m, void *v)
806 {
807         mutex_unlock(&probe_lock);
808 }
809
810 static int probes_seq_show(struct seq_file *m, void *v)
811 {
812         struct trace_probe *tp = v;
813         int i, ret;
814         char buf[MAX_ARGSTR_LEN + 1];
815
816         seq_printf(m, "%c", probe_is_return(tp) ? 'r' : 'p');
817         seq_printf(m, ":%s/%s", tp->call.system, tp->call.name);
818
819         if (!tp->symbol)
820                 seq_printf(m, " 0x%p", tp->rp.kp.addr);
821         else if (tp->rp.kp.offset)
822                 seq_printf(m, " %s+%u", probe_symbol(tp), tp->rp.kp.offset);
823         else
824                 seq_printf(m, " %s", probe_symbol(tp));
825
826         for (i = 0; i < tp->nr_args; i++) {
827                 ret = probe_arg_string(buf, MAX_ARGSTR_LEN, &tp->args[i].fetch);
828                 if (ret < 0) {
829                         pr_warning("Argument%d decoding error(%d).\n", i, ret);
830                         return ret;
831                 }
832                 seq_printf(m, " %s=%s", tp->args[i].name, buf);
833         }
834         seq_printf(m, "\n");
835         return 0;
836 }
837
838 static const struct seq_operations probes_seq_op = {
839         .start  = probes_seq_start,
840         .next   = probes_seq_next,
841         .stop   = probes_seq_stop,
842         .show   = probes_seq_show
843 };
844
845 static int probes_open(struct inode *inode, struct file *file)
846 {
847         if ((file->f_mode & FMODE_WRITE) &&
848             (file->f_flags & O_TRUNC))
849                 cleanup_all_probes();
850
851         return seq_open(file, &probes_seq_op);
852 }
853
854 static int command_trace_probe(const char *buf)
855 {
856         char **argv;
857         int argc = 0, ret = 0;
858
859         argv = argv_split(GFP_KERNEL, buf, &argc);
860         if (!argv)
861                 return -ENOMEM;
862
863         if (argc)
864                 ret = create_trace_probe(argc, argv);
865
866         argv_free(argv);
867         return ret;
868 }
869
870 #define WRITE_BUFSIZE 128
871
872 static ssize_t probes_write(struct file *file, const char __user *buffer,
873                             size_t count, loff_t *ppos)
874 {
875         char *kbuf, *tmp;
876         int ret;
877         size_t done;
878         size_t size;
879
880         kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL);
881         if (!kbuf)
882                 return -ENOMEM;
883
884         ret = done = 0;
885         while (done < count) {
886                 size = count - done;
887                 if (size >= WRITE_BUFSIZE)
888                         size = WRITE_BUFSIZE - 1;
889                 if (copy_from_user(kbuf, buffer + done, size)) {
890                         ret = -EFAULT;
891                         goto out;
892                 }
893                 kbuf[size] = '\0';
894                 tmp = strchr(kbuf, '\n');
895                 if (tmp) {
896                         *tmp = '\0';
897                         size = tmp - kbuf + 1;
898                 } else if (done + size < count) {
899                         pr_warning("Line length is too long: "
900                                    "Should be less than %d.", WRITE_BUFSIZE);
901                         ret = -EINVAL;
902                         goto out;
903                 }
904                 done += size;
905                 /* Remove comments */
906                 tmp = strchr(kbuf, '#');
907                 if (tmp)
908                         *tmp = '\0';
909
910                 ret = command_trace_probe(kbuf);
911                 if (ret)
912                         goto out;
913         }
914         ret = done;
915 out:
916         kfree(kbuf);
917         return ret;
918 }
919
920 static const struct file_operations kprobe_events_ops = {
921         .owner          = THIS_MODULE,
922         .open           = probes_open,
923         .read           = seq_read,
924         .llseek         = seq_lseek,
925         .release        = seq_release,
926         .write          = probes_write,
927 };
928
929 /* Probes profiling interfaces */
930 static int probes_profile_seq_show(struct seq_file *m, void *v)
931 {
932         struct trace_probe *tp = v;
933
934         seq_printf(m, "  %-44s %15lu %15lu\n", tp->call.name, tp->nhit,
935                    tp->rp.kp.nmissed);
936
937         return 0;
938 }
939
940 static const struct seq_operations profile_seq_op = {
941         .start  = probes_seq_start,
942         .next   = probes_seq_next,
943         .stop   = probes_seq_stop,
944         .show   = probes_profile_seq_show
945 };
946
947 static int profile_open(struct inode *inode, struct file *file)
948 {
949         return seq_open(file, &profile_seq_op);
950 }
951
952 static const struct file_operations kprobe_profile_ops = {
953         .owner          = THIS_MODULE,
954         .open           = profile_open,
955         .read           = seq_read,
956         .llseek         = seq_lseek,
957         .release        = seq_release,
958 };
959
960 /* Kprobe handler */
961 static __kprobes int kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs)
962 {
963         struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
964         struct kprobe_trace_entry *entry;
965         struct ring_buffer_event *event;
966         struct ring_buffer *buffer;
967         int size, i, pc;
968         unsigned long irq_flags;
969         struct ftrace_event_call *call = &tp->call;
970
971         tp->nhit++;
972
973         local_save_flags(irq_flags);
974         pc = preempt_count();
975
976         size = SIZEOF_KPROBE_TRACE_ENTRY(tp->nr_args);
977
978         event = trace_current_buffer_lock_reserve(&buffer, call->id, size,
979                                                   irq_flags, pc);
980         if (!event)
981                 return 0;
982
983         entry = ring_buffer_event_data(event);
984         entry->nargs = tp->nr_args;
985         entry->ip = (unsigned long)kp->addr;
986         for (i = 0; i < tp->nr_args; i++)
987                 entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
988
989         if (!filter_current_check_discard(buffer, call, entry, event))
990                 trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc);
991         return 0;
992 }
993
994 /* Kretprobe handler */
995 static __kprobes int kretprobe_trace_func(struct kretprobe_instance *ri,
996                                           struct pt_regs *regs)
997 {
998         struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
999         struct kretprobe_trace_entry *entry;
1000         struct ring_buffer_event *event;
1001         struct ring_buffer *buffer;
1002         int size, i, pc;
1003         unsigned long irq_flags;
1004         struct ftrace_event_call *call = &tp->call;
1005
1006         local_save_flags(irq_flags);
1007         pc = preempt_count();
1008
1009         size = SIZEOF_KRETPROBE_TRACE_ENTRY(tp->nr_args);
1010
1011         event = trace_current_buffer_lock_reserve(&buffer, call->id, size,
1012                                                   irq_flags, pc);
1013         if (!event)
1014                 return 0;
1015
1016         entry = ring_buffer_event_data(event);
1017         entry->nargs = tp->nr_args;
1018         entry->func = (unsigned long)tp->rp.kp.addr;
1019         entry->ret_ip = (unsigned long)ri->ret_addr;
1020         for (i = 0; i < tp->nr_args; i++)
1021                 entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
1022
1023         if (!filter_current_check_discard(buffer, call, entry, event))
1024                 trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc);
1025
1026         return 0;
1027 }
1028
1029 /* Event entry printers */
1030 enum print_line_t
1031 print_kprobe_event(struct trace_iterator *iter, int flags)
1032 {
1033         struct kprobe_trace_entry *field;
1034         struct trace_seq *s = &iter->seq;
1035         struct trace_event *event;
1036         struct trace_probe *tp;
1037         int i;
1038
1039         field = (struct kprobe_trace_entry *)iter->ent;
1040         event = ftrace_find_event(field->ent.type);
1041         tp = container_of(event, struct trace_probe, event);
1042
1043         if (!trace_seq_printf(s, "%s: (", tp->call.name))
1044                 goto partial;
1045
1046         if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET))
1047                 goto partial;
1048
1049         if (!trace_seq_puts(s, ")"))
1050                 goto partial;
1051
1052         for (i = 0; i < field->nargs; i++)
1053                 if (!trace_seq_printf(s, " %s=%lx",
1054                                       tp->args[i].name, field->args[i]))
1055                         goto partial;
1056
1057         if (!trace_seq_puts(s, "\n"))
1058                 goto partial;
1059
1060         return TRACE_TYPE_HANDLED;
1061 partial:
1062         return TRACE_TYPE_PARTIAL_LINE;
1063 }
1064
1065 enum print_line_t
1066 print_kretprobe_event(struct trace_iterator *iter, int flags)
1067 {
1068         struct kretprobe_trace_entry *field;
1069         struct trace_seq *s = &iter->seq;
1070         struct trace_event *event;
1071         struct trace_probe *tp;
1072         int i;
1073
1074         field = (struct kretprobe_trace_entry *)iter->ent;
1075         event = ftrace_find_event(field->ent.type);
1076         tp = container_of(event, struct trace_probe, event);
1077
1078         if (!trace_seq_printf(s, "%s: (", tp->call.name))
1079                 goto partial;
1080
1081         if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET))
1082                 goto partial;
1083
1084         if (!trace_seq_puts(s, " <- "))
1085                 goto partial;
1086
1087         if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET))
1088                 goto partial;
1089
1090         if (!trace_seq_puts(s, ")"))
1091                 goto partial;
1092
1093         for (i = 0; i < field->nargs; i++)
1094                 if (!trace_seq_printf(s, " %s=%lx",
1095                                       tp->args[i].name, field->args[i]))
1096                         goto partial;
1097
1098         if (!trace_seq_puts(s, "\n"))
1099                 goto partial;
1100
1101         return TRACE_TYPE_HANDLED;
1102 partial:
1103         return TRACE_TYPE_PARTIAL_LINE;
1104 }
1105
1106 static int probe_event_enable(struct ftrace_event_call *call)
1107 {
1108         struct trace_probe *tp = (struct trace_probe *)call->data;
1109
1110         tp->flags |= TP_FLAG_TRACE;
1111         if (probe_is_return(tp))
1112                 return enable_kretprobe(&tp->rp);
1113         else
1114                 return enable_kprobe(&tp->rp.kp);
1115 }
1116
1117 static void probe_event_disable(struct ftrace_event_call *call)
1118 {
1119         struct trace_probe *tp = (struct trace_probe *)call->data;
1120
1121         tp->flags &= ~TP_FLAG_TRACE;
1122         if (!(tp->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE))) {
1123                 if (probe_is_return(tp))
1124                         disable_kretprobe(&tp->rp);
1125                 else
1126                         disable_kprobe(&tp->rp.kp);
1127         }
1128 }
1129
1130 static int probe_event_raw_init(struct ftrace_event_call *event_call)
1131 {
1132         INIT_LIST_HEAD(&event_call->fields);
1133
1134         return 0;
1135 }
1136
1137 #undef DEFINE_FIELD
1138 #define DEFINE_FIELD(type, item, name, is_signed)                       \
1139         do {                                                            \
1140                 ret = trace_define_field(event_call, #type, name,       \
1141                                          offsetof(typeof(field), item), \
1142                                          sizeof(field.item), is_signed, \
1143                                          FILTER_OTHER);                 \
1144                 if (ret)                                                \
1145                         return ret;                                     \
1146         } while (0)
1147
1148 static int kprobe_event_define_fields(struct ftrace_event_call *event_call)
1149 {
1150         int ret, i;
1151         struct kprobe_trace_entry field;
1152         struct trace_probe *tp = (struct trace_probe *)event_call->data;
1153
1154         DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0);
1155         DEFINE_FIELD(int, nargs, FIELD_STRING_NARGS, 1);
1156         /* Set argument names as fields */
1157         for (i = 0; i < tp->nr_args; i++)
1158                 DEFINE_FIELD(unsigned long, args[i], tp->args[i].name, 0);
1159         return 0;
1160 }
1161
1162 static int kretprobe_event_define_fields(struct ftrace_event_call *event_call)
1163 {
1164         int ret, i;
1165         struct kretprobe_trace_entry field;
1166         struct trace_probe *tp = (struct trace_probe *)event_call->data;
1167
1168         DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0);
1169         DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0);
1170         DEFINE_FIELD(int, nargs, FIELD_STRING_NARGS, 1);
1171         /* Set argument names as fields */
1172         for (i = 0; i < tp->nr_args; i++)
1173                 DEFINE_FIELD(unsigned long, args[i], tp->args[i].name, 0);
1174         return 0;
1175 }
1176
1177 static int __probe_event_show_format(struct trace_seq *s,
1178                                      struct trace_probe *tp, const char *fmt,
1179                                      const char *arg)
1180 {
1181         int i;
1182
1183         /* Show format */
1184         if (!trace_seq_printf(s, "\nprint fmt: \"%s", fmt))
1185                 return 0;
1186
1187         for (i = 0; i < tp->nr_args; i++)
1188                 if (!trace_seq_printf(s, " %s=%%lx", tp->args[i].name))
1189                         return 0;
1190
1191         if (!trace_seq_printf(s, "\", %s", arg))
1192                 return 0;
1193
1194         for (i = 0; i < tp->nr_args; i++)
1195                 if (!trace_seq_printf(s, ", REC->%s", tp->args[i].name))
1196                         return 0;
1197
1198         return trace_seq_puts(s, "\n");
1199 }
1200
1201 #undef SHOW_FIELD
1202 #define SHOW_FIELD(type, item, name)                                    \
1203         do {                                                            \
1204                 ret = trace_seq_printf(s, "\tfield: " #type " %s;\t"    \
1205                                 "offset:%u;\tsize:%u;\n", name,         \
1206                                 (unsigned int)offsetof(typeof(field), item),\
1207                                 (unsigned int)sizeof(type));            \
1208                 if (!ret)                                               \
1209                         return 0;                                       \
1210         } while (0)
1211
1212 static int kprobe_event_show_format(struct ftrace_event_call *call,
1213                                     struct trace_seq *s)
1214 {
1215         struct kprobe_trace_entry field __attribute__((unused));
1216         int ret, i;
1217         struct trace_probe *tp = (struct trace_probe *)call->data;
1218
1219         SHOW_FIELD(unsigned long, ip, FIELD_STRING_IP);
1220         SHOW_FIELD(int, nargs, FIELD_STRING_NARGS);
1221
1222         /* Show fields */
1223         for (i = 0; i < tp->nr_args; i++)
1224                 SHOW_FIELD(unsigned long, args[i], tp->args[i].name);
1225         trace_seq_puts(s, "\n");
1226
1227         return __probe_event_show_format(s, tp, "(%lx)",
1228                                          "REC->" FIELD_STRING_IP);
1229 }
1230
1231 static int kretprobe_event_show_format(struct ftrace_event_call *call,
1232                                        struct trace_seq *s)
1233 {
1234         struct kretprobe_trace_entry field __attribute__((unused));
1235         int ret, i;
1236         struct trace_probe *tp = (struct trace_probe *)call->data;
1237
1238         SHOW_FIELD(unsigned long, func, FIELD_STRING_FUNC);
1239         SHOW_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP);
1240         SHOW_FIELD(int, nargs, FIELD_STRING_NARGS);
1241
1242         /* Show fields */
1243         for (i = 0; i < tp->nr_args; i++)
1244                 SHOW_FIELD(unsigned long, args[i], tp->args[i].name);
1245         trace_seq_puts(s, "\n");
1246
1247         return __probe_event_show_format(s, tp, "(%lx <- %lx)",
1248                                          "REC->" FIELD_STRING_FUNC
1249                                          ", REC->" FIELD_STRING_RETIP);
1250 }
1251
1252 #ifdef CONFIG_EVENT_PROFILE
1253
1254 /* Kprobe profile handler */
1255 static __kprobes int kprobe_profile_func(struct kprobe *kp,
1256                                          struct pt_regs *regs)
1257 {
1258         struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
1259         struct ftrace_event_call *call = &tp->call;
1260         struct kprobe_trace_entry *entry;
1261         struct trace_entry *ent;
1262         int size, __size, i, pc, __cpu;
1263         unsigned long irq_flags;
1264         char *trace_buf;
1265         char *raw_data;
1266         int rctx;
1267
1268         pc = preempt_count();
1269         __size = SIZEOF_KPROBE_TRACE_ENTRY(tp->nr_args);
1270         size = ALIGN(__size + sizeof(u32), sizeof(u64));
1271         size -= sizeof(u32);
1272         if (WARN_ONCE(size > FTRACE_MAX_PROFILE_SIZE,
1273                      "profile buffer not large enough"))
1274                 return 0;
1275
1276         /*
1277          * Protect the non nmi buffer
1278          * This also protects the rcu read side
1279          */
1280         local_irq_save(irq_flags);
1281
1282         rctx = perf_swevent_get_recursion_context();
1283         if (rctx < 0)
1284                 goto end_recursion;
1285
1286         __cpu = smp_processor_id();
1287
1288         if (in_nmi())
1289                 trace_buf = rcu_dereference(perf_trace_buf_nmi);
1290         else
1291                 trace_buf = rcu_dereference(perf_trace_buf);
1292
1293         if (!trace_buf)
1294                 goto end;
1295
1296         raw_data = per_cpu_ptr(trace_buf, __cpu);
1297
1298         /* Zero dead bytes from alignment to avoid buffer leak to userspace */
1299         *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
1300         entry = (struct kprobe_trace_entry *)raw_data;
1301         ent = &entry->ent;
1302
1303         tracing_generic_entry_update(ent, irq_flags, pc);
1304         ent->type = call->id;
1305         entry->nargs = tp->nr_args;
1306         entry->ip = (unsigned long)kp->addr;
1307         for (i = 0; i < tp->nr_args; i++)
1308                 entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
1309         perf_tp_event(call->id, entry->ip, 1, entry, size);
1310
1311 end:
1312         perf_swevent_put_recursion_context(rctx);
1313 end_recursion:
1314         local_irq_restore(irq_flags);
1315
1316         return 0;
1317 }
1318
1319 /* Kretprobe profile handler */
1320 static __kprobes int kretprobe_profile_func(struct kretprobe_instance *ri,
1321                                             struct pt_regs *regs)
1322 {
1323         struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
1324         struct ftrace_event_call *call = &tp->call;
1325         struct kretprobe_trace_entry *entry;
1326         struct trace_entry *ent;
1327         int size, __size, i, pc, __cpu;
1328         unsigned long irq_flags;
1329         char *trace_buf;
1330         char *raw_data;
1331         int rctx;
1332
1333         pc = preempt_count();
1334         __size = SIZEOF_KRETPROBE_TRACE_ENTRY(tp->nr_args);
1335         size = ALIGN(__size + sizeof(u32), sizeof(u64));
1336         size -= sizeof(u32);
1337         if (WARN_ONCE(size > FTRACE_MAX_PROFILE_SIZE,
1338                      "profile buffer not large enough"))
1339                 return 0;
1340
1341         /*
1342          * Protect the non nmi buffer
1343          * This also protects the rcu read side
1344          */
1345         local_irq_save(irq_flags);
1346
1347         rctx = perf_swevent_get_recursion_context();
1348         if (rctx < 0)
1349                 goto end_recursion;
1350
1351         __cpu = smp_processor_id();
1352
1353         if (in_nmi())
1354                 trace_buf = rcu_dereference(perf_trace_buf_nmi);
1355         else
1356                 trace_buf = rcu_dereference(perf_trace_buf);
1357
1358         if (!trace_buf)
1359                 goto end;
1360
1361         raw_data = per_cpu_ptr(trace_buf, __cpu);
1362
1363         /* Zero dead bytes from alignment to avoid buffer leak to userspace */
1364         *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
1365         entry = (struct kretprobe_trace_entry *)raw_data;
1366         ent = &entry->ent;
1367
1368         tracing_generic_entry_update(ent, irq_flags, pc);
1369         ent->type = call->id;
1370         entry->nargs = tp->nr_args;
1371         entry->func = (unsigned long)tp->rp.kp.addr;
1372         entry->ret_ip = (unsigned long)ri->ret_addr;
1373         for (i = 0; i < tp->nr_args; i++)
1374                 entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
1375         perf_tp_event(call->id, entry->ret_ip, 1, entry, size);
1376
1377 end:
1378         perf_swevent_put_recursion_context(rctx);
1379 end_recursion:
1380         local_irq_restore(irq_flags);
1381
1382         return 0;
1383 }
1384
1385 static int probe_profile_enable(struct ftrace_event_call *call)
1386 {
1387         struct trace_probe *tp = (struct trace_probe *)call->data;
1388
1389         tp->flags |= TP_FLAG_PROFILE;
1390
1391         if (probe_is_return(tp))
1392                 return enable_kretprobe(&tp->rp);
1393         else
1394                 return enable_kprobe(&tp->rp.kp);
1395 }
1396
1397 static void probe_profile_disable(struct ftrace_event_call *call)
1398 {
1399         struct trace_probe *tp = (struct trace_probe *)call->data;
1400
1401         tp->flags &= ~TP_FLAG_PROFILE;
1402
1403         if (!(tp->flags & TP_FLAG_TRACE)) {
1404                 if (probe_is_return(tp))
1405                         disable_kretprobe(&tp->rp);
1406                 else
1407                         disable_kprobe(&tp->rp.kp);
1408         }
1409 }
1410 #endif  /* CONFIG_EVENT_PROFILE */
1411
1412
1413 static __kprobes
1414 int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs)
1415 {
1416         struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
1417
1418         if (tp->flags & TP_FLAG_TRACE)
1419                 kprobe_trace_func(kp, regs);
1420 #ifdef CONFIG_EVENT_PROFILE
1421         if (tp->flags & TP_FLAG_PROFILE)
1422                 kprobe_profile_func(kp, regs);
1423 #endif  /* CONFIG_EVENT_PROFILE */
1424         return 0;       /* We don't tweek kernel, so just return 0 */
1425 }
1426
1427 static __kprobes
1428 int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs)
1429 {
1430         struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
1431
1432         if (tp->flags & TP_FLAG_TRACE)
1433                 kretprobe_trace_func(ri, regs);
1434 #ifdef CONFIG_EVENT_PROFILE
1435         if (tp->flags & TP_FLAG_PROFILE)
1436                 kretprobe_profile_func(ri, regs);
1437 #endif  /* CONFIG_EVENT_PROFILE */
1438         return 0;       /* We don't tweek kernel, so just return 0 */
1439 }
1440
1441 static int register_probe_event(struct trace_probe *tp)
1442 {
1443         struct ftrace_event_call *call = &tp->call;
1444         int ret;
1445
1446         /* Initialize ftrace_event_call */
1447         if (probe_is_return(tp)) {
1448                 tp->event.trace = print_kretprobe_event;
1449                 call->raw_init = probe_event_raw_init;
1450                 call->show_format = kretprobe_event_show_format;
1451                 call->define_fields = kretprobe_event_define_fields;
1452         } else {
1453                 tp->event.trace = print_kprobe_event;
1454                 call->raw_init = probe_event_raw_init;
1455                 call->show_format = kprobe_event_show_format;
1456                 call->define_fields = kprobe_event_define_fields;
1457         }
1458         call->event = &tp->event;
1459         call->id = register_ftrace_event(&tp->event);
1460         if (!call->id)
1461                 return -ENODEV;
1462         call->enabled = 0;
1463         call->regfunc = probe_event_enable;
1464         call->unregfunc = probe_event_disable;
1465
1466 #ifdef CONFIG_EVENT_PROFILE
1467         call->profile_enable = probe_profile_enable;
1468         call->profile_disable = probe_profile_disable;
1469 #endif
1470         call->data = tp;
1471         ret = trace_add_event_call(call);
1472         if (ret) {
1473                 pr_info("Failed to register kprobe event: %s\n", call->name);
1474                 unregister_ftrace_event(&tp->event);
1475         }
1476         return ret;
1477 }
1478
1479 static void unregister_probe_event(struct trace_probe *tp)
1480 {
1481         /* tp->event is unregistered in trace_remove_event_call() */
1482         trace_remove_event_call(&tp->call);
1483 }
1484
1485 /* Make a debugfs interface for controling probe points */
1486 static __init int init_kprobe_trace(void)
1487 {
1488         struct dentry *d_tracer;
1489         struct dentry *entry;
1490
1491         d_tracer = tracing_init_dentry();
1492         if (!d_tracer)
1493                 return 0;
1494
1495         entry = debugfs_create_file("kprobe_events", 0644, d_tracer,
1496                                     NULL, &kprobe_events_ops);
1497
1498         /* Event list interface */
1499         if (!entry)
1500                 pr_warning("Could not create debugfs "
1501                            "'kprobe_events' entry\n");
1502
1503         /* Profile interface */
1504         entry = debugfs_create_file("kprobe_profile", 0444, d_tracer,
1505                                     NULL, &kprobe_profile_ops);
1506
1507         if (!entry)
1508                 pr_warning("Could not create debugfs "
1509                            "'kprobe_profile' entry\n");
1510         return 0;
1511 }
1512 fs_initcall(init_kprobe_trace);
1513
1514
1515 #ifdef CONFIG_FTRACE_STARTUP_TEST
1516
1517 static int kprobe_trace_selftest_target(int a1, int a2, int a3,
1518                                         int a4, int a5, int a6)
1519 {
1520         return a1 + a2 + a3 + a4 + a5 + a6;
1521 }
1522
1523 static __init int kprobe_trace_self_tests_init(void)
1524 {
1525         int ret;
1526         int (*target)(int, int, int, int, int, int);
1527
1528         target = kprobe_trace_selftest_target;
1529
1530         pr_info("Testing kprobe tracing: ");
1531
1532         ret = command_trace_probe("p:testprobe kprobe_trace_selftest_target "
1533                                   "$arg1 $arg2 $arg3 $arg4 $stack $stack0");
1534         if (WARN_ON_ONCE(ret))
1535                 pr_warning("error enabling function entry\n");
1536
1537         ret = command_trace_probe("r:testprobe2 kprobe_trace_selftest_target "
1538                                   "$retval");
1539         if (WARN_ON_ONCE(ret))
1540                 pr_warning("error enabling function return\n");
1541
1542         ret = target(1, 2, 3, 4, 5, 6);
1543
1544         cleanup_all_probes();
1545
1546         pr_cont("OK\n");
1547         return 0;
1548 }
1549
1550 late_initcall(kprobe_trace_self_tests_init);
1551
1552 #endif