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1/*
2 * Common code for probe-based Dynamic events.
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License
14 * along with this program; if not, write to the Free Software
15 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
16 *
17 * This code was copied from kernel/trace/trace_kprobe.c written by
18 * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
19 *
20 * Updates to make this generic:
21 * Copyright (C) IBM Corporation, 2010-2011
22 * Author: Srikar Dronamraju
23 */
24
25#include "trace_probe.h"
26
27const char *reserved_field_names[] = {
28 "common_type",
29 "common_flags",
30 "common_preempt_count",
31 "common_pid",
32 "common_tgid",
33 FIELD_STRING_IP,
34 FIELD_STRING_RETIP,
35 FIELD_STRING_FUNC,
36};
37
38/* Printing function type */
39#define PRINT_TYPE_FUNC_NAME(type) print_type_##type
40#define PRINT_TYPE_FMT_NAME(type) print_type_format_##type
41
42/* Printing in basic type function template */
43#define DEFINE_BASIC_PRINT_TYPE_FUNC(type, fmt, cast) \
44static __kprobes int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, \
45 const char *name, \
46 void *data, void *ent)\
47{ \
48 return trace_seq_printf(s, " %s=" fmt, name, (cast)*(type *)data);\
49} \
50static const char PRINT_TYPE_FMT_NAME(type)[] = fmt;
51
52DEFINE_BASIC_PRINT_TYPE_FUNC(u8, "%x", unsigned int)
53DEFINE_BASIC_PRINT_TYPE_FUNC(u16, "%x", unsigned int)
54DEFINE_BASIC_PRINT_TYPE_FUNC(u32, "%lx", unsigned long)
55DEFINE_BASIC_PRINT_TYPE_FUNC(u64, "%llx", unsigned long long)
56DEFINE_BASIC_PRINT_TYPE_FUNC(s8, "%d", int)
57DEFINE_BASIC_PRINT_TYPE_FUNC(s16, "%d", int)
58DEFINE_BASIC_PRINT_TYPE_FUNC(s32, "%ld", long)
59DEFINE_BASIC_PRINT_TYPE_FUNC(s64, "%lld", long long)
60
61static inline void *get_rloc_data(u32 *dl)
62{
63 return (u8 *)dl + get_rloc_offs(*dl);
64}
65
66/* For data_loc conversion */
67static inline void *get_loc_data(u32 *dl, void *ent)
68{
69 return (u8 *)ent + get_rloc_offs(*dl);
70}
71
72/* For defining macros, define string/string_size types */
73typedef u32 string;
74typedef u32 string_size;
75
76/* Print type function for string type */
77static __kprobes int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s,
78 const char *name,
79 void *data, void *ent)
80{
81 int len = *(u32 *)data >> 16;
82
83 if (!len)
84 return trace_seq_printf(s, " %s=(fault)", name);
85 else
86 return trace_seq_printf(s, " %s=\"%s\"", name,
87 (const char *)get_loc_data(data, ent));
88}
89
90static const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\"";
91
92#define FETCH_FUNC_NAME(method, type) fetch_##method##_##type
93/*
94 * Define macro for basic types - we don't need to define s* types, because
95 * we have to care only about bitwidth at recording time.
96 */
97#define DEFINE_BASIC_FETCH_FUNCS(method) \
98DEFINE_FETCH_##method(u8) \
99DEFINE_FETCH_##method(u16) \
100DEFINE_FETCH_##method(u32) \
101DEFINE_FETCH_##method(u64)
102
103#define CHECK_FETCH_FUNCS(method, fn) \
104 (((FETCH_FUNC_NAME(method, u8) == fn) || \
105 (FETCH_FUNC_NAME(method, u16) == fn) || \
106 (FETCH_FUNC_NAME(method, u32) == fn) || \
107 (FETCH_FUNC_NAME(method, u64) == fn) || \
108 (FETCH_FUNC_NAME(method, string) == fn) || \
109 (FETCH_FUNC_NAME(method, string_size) == fn)) \
110 && (fn != NULL))
111
112/* Data fetch function templates */
113#define DEFINE_FETCH_reg(type) \
114static __kprobes void FETCH_FUNC_NAME(reg, type)(struct pt_regs *regs, \
115 void *offset, void *dest) \
116{ \
117 *(type *)dest = (type)regs_get_register(regs, \
118 (unsigned int)((unsigned long)offset)); \
119}
120DEFINE_BASIC_FETCH_FUNCS(reg)
121/* No string on the register */
122#define fetch_reg_string NULL
123#define fetch_reg_string_size NULL
124
125#define DEFINE_FETCH_stack(type) \
126static __kprobes void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,\
127 void *offset, void *dest) \
128{ \
129 *(type *)dest = (type)regs_get_kernel_stack_nth(regs, \
130 (unsigned int)((unsigned long)offset)); \
131}
132DEFINE_BASIC_FETCH_FUNCS(stack)
133/* No string on the stack entry */
134#define fetch_stack_string NULL
135#define fetch_stack_string_size NULL
136
137#define DEFINE_FETCH_retval(type) \
138static __kprobes void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs,\
139 void *dummy, void *dest) \
140{ \
141 *(type *)dest = (type)regs_return_value(regs); \
142}
143DEFINE_BASIC_FETCH_FUNCS(retval)
144/* No string on the retval */
145#define fetch_retval_string NULL
146#define fetch_retval_string_size NULL
147
148#define DEFINE_FETCH_memory(type) \
149static __kprobes void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs,\
150 void *addr, void *dest) \
151{ \
152 type retval; \
153 if (probe_kernel_address(addr, retval)) \
154 *(type *)dest = 0; \
155 else \
156 *(type *)dest = retval; \
157}
158DEFINE_BASIC_FETCH_FUNCS(memory)
159/*
160 * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
161 * length and relative data location.
162 */
163static __kprobes void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs,
164 void *addr, void *dest)
165{
166 long ret;
167 int maxlen = get_rloc_len(*(u32 *)dest);
168 u8 *dst = get_rloc_data(dest);
169 u8 *src = addr;
170 mm_segment_t old_fs = get_fs();
171
172 if (!maxlen)
173 return;
174
175 /*
176 * Try to get string again, since the string can be changed while
177 * probing.
178 */
179 set_fs(KERNEL_DS);
180 pagefault_disable();
181
182 do
183 ret = __copy_from_user_inatomic(dst++, src++, 1);
184 while (dst[-1] && ret == 0 && src - (u8 *)addr < maxlen);
185
186 dst[-1] = '\0';
187 pagefault_enable();
188 set_fs(old_fs);
189
190 if (ret < 0) { /* Failed to fetch string */
191 ((u8 *)get_rloc_data(dest))[0] = '\0';
192 *(u32 *)dest = make_data_rloc(0, get_rloc_offs(*(u32 *)dest));
193 } else {
194 *(u32 *)dest = make_data_rloc(src - (u8 *)addr,
195 get_rloc_offs(*(u32 *)dest));
196 }
197}
198
199/* Return the length of string -- including null terminal byte */
200static __kprobes void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs,
201 void *addr, void *dest)
202{
203 mm_segment_t old_fs;
204 int ret, len = 0;
205 u8 c;
206
207 old_fs = get_fs();
208 set_fs(KERNEL_DS);
209 pagefault_disable();
210
211 do {
212 ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1);
213 len++;
214 } while (c && ret == 0 && len < MAX_STRING_SIZE);
215
216 pagefault_enable();
217 set_fs(old_fs);
218
219 if (ret < 0) /* Failed to check the length */
220 *(u32 *)dest = 0;
221 else
222 *(u32 *)dest = len;
223}
224
225/* Memory fetching by symbol */
226struct symbol_cache {
227 char *symbol;
228 long offset;
229 unsigned long addr;
230};
231
232static unsigned long update_symbol_cache(struct symbol_cache *sc)
233{
234 sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol);
235
236 if (sc->addr)
237 sc->addr += sc->offset;
238
239 return sc->addr;
240}
241
242static void free_symbol_cache(struct symbol_cache *sc)
243{
244 kfree(sc->symbol);
245 kfree(sc);
246}
247
248static struct symbol_cache *alloc_symbol_cache(const char *sym, long offset)
249{
250 struct symbol_cache *sc;
251
252 if (!sym || strlen(sym) == 0)
253 return NULL;
254
255 sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL);
256 if (!sc)
257 return NULL;
258
259 sc->symbol = kstrdup(sym, GFP_KERNEL);
260 if (!sc->symbol) {
261 kfree(sc);
262 return NULL;
263 }
264 sc->offset = offset;
265 update_symbol_cache(sc);
266
267 return sc;
268}
269
270#define DEFINE_FETCH_symbol(type) \
271static __kprobes void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs,\
272 void *data, void *dest) \
273{ \
274 struct symbol_cache *sc = data; \
275 if (sc->addr) \
276 fetch_memory_##type(regs, (void *)sc->addr, dest); \
277 else \
278 *(type *)dest = 0; \
279}
280DEFINE_BASIC_FETCH_FUNCS(symbol)
281DEFINE_FETCH_symbol(string)
282DEFINE_FETCH_symbol(string_size)
283
284/* Dereference memory access function */
285struct deref_fetch_param {
286 struct fetch_param orig;
287 long offset;
288};
289
290#define DEFINE_FETCH_deref(type) \
291static __kprobes void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs,\
292 void *data, void *dest) \
293{ \
294 struct deref_fetch_param *dprm = data; \
295 unsigned long addr; \
296 call_fetch(&dprm->orig, regs, &addr); \
297 if (addr) { \
298 addr += dprm->offset; \
299 fetch_memory_##type(regs, (void *)addr, dest); \
300 } else \
301 *(type *)dest = 0; \
302}
303DEFINE_BASIC_FETCH_FUNCS(deref)
304DEFINE_FETCH_deref(string)
305DEFINE_FETCH_deref(string_size)
306
307static __kprobes void update_deref_fetch_param(struct deref_fetch_param *data)
308{
309 if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
310 update_deref_fetch_param(data->orig.data);
311 else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
312 update_symbol_cache(data->orig.data);
313}
314
315static __kprobes void free_deref_fetch_param(struct deref_fetch_param *data)
316{
317 if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
318 free_deref_fetch_param(data->orig.data);
319 else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
320 free_symbol_cache(data->orig.data);
321 kfree(data);
322}
323
324/* Bitfield fetch function */
325struct bitfield_fetch_param {
326 struct fetch_param orig;
327 unsigned char hi_shift;
328 unsigned char low_shift;
329};
330
331#define DEFINE_FETCH_bitfield(type) \
332static __kprobes void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs,\
333 void *data, void *dest) \
334{ \
335 struct bitfield_fetch_param *bprm = data; \
336 type buf = 0; \
337 call_fetch(&bprm->orig, regs, &buf); \
338 if (buf) { \
339 buf <<= bprm->hi_shift; \
340 buf >>= bprm->low_shift; \
341 } \
342 *(type *)dest = buf; \
343}
344
345DEFINE_BASIC_FETCH_FUNCS(bitfield)
346#define fetch_bitfield_string NULL
347#define fetch_bitfield_string_size NULL
348
349static __kprobes void
350update_bitfield_fetch_param(struct bitfield_fetch_param *data)
351{
352 /*
353 * Don't check the bitfield itself, because this must be the
354 * last fetch function.
355 */
356 if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
357 update_deref_fetch_param(data->orig.data);
358 else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
359 update_symbol_cache(data->orig.data);
360}
361
362static __kprobes void
363free_bitfield_fetch_param(struct bitfield_fetch_param *data)
364{
365 /*
366 * Don't check the bitfield itself, because this must be the
367 * last fetch function.
368 */
369 if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
370 free_deref_fetch_param(data->orig.data);
371 else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
372 free_symbol_cache(data->orig.data);
373
374 kfree(data);
375}
376
377/* Default (unsigned long) fetch type */
378#define __DEFAULT_FETCH_TYPE(t) u##t
379#define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t)
380#define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG)
381#define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE)
382
383#define ASSIGN_FETCH_FUNC(method, type) \
384 [FETCH_MTD_##method] = FETCH_FUNC_NAME(method, type)
385
386#define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \
387 {.name = _name, \
388 .size = _size, \
389 .is_signed = sign, \
390 .print = PRINT_TYPE_FUNC_NAME(ptype), \
391 .fmt = PRINT_TYPE_FMT_NAME(ptype), \
392 .fmttype = _fmttype, \
393 .fetch = { \
394ASSIGN_FETCH_FUNC(reg, ftype), \
395ASSIGN_FETCH_FUNC(stack, ftype), \
396ASSIGN_FETCH_FUNC(retval, ftype), \
397ASSIGN_FETCH_FUNC(memory, ftype), \
398ASSIGN_FETCH_FUNC(symbol, ftype), \
399ASSIGN_FETCH_FUNC(deref, ftype), \
400ASSIGN_FETCH_FUNC(bitfield, ftype), \
401 } \
402 }
403
404#define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \
405 __ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #ptype)
406
407#define FETCH_TYPE_STRING 0
408#define FETCH_TYPE_STRSIZE 1
409
410/* Fetch type information table */
411static const struct fetch_type fetch_type_table[] = {
412 /* Special types */
413 [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string,
414 sizeof(u32), 1, "__data_loc char[]"),
415 [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32,
416 string_size, sizeof(u32), 0, "u32"),
417 /* Basic types */
418 ASSIGN_FETCH_TYPE(u8, u8, 0),
419 ASSIGN_FETCH_TYPE(u16, u16, 0),
420 ASSIGN_FETCH_TYPE(u32, u32, 0),
421 ASSIGN_FETCH_TYPE(u64, u64, 0),
422 ASSIGN_FETCH_TYPE(s8, u8, 1),
423 ASSIGN_FETCH_TYPE(s16, u16, 1),
424 ASSIGN_FETCH_TYPE(s32, u32, 1),
425 ASSIGN_FETCH_TYPE(s64, u64, 1),
426};
427
428static const struct fetch_type *find_fetch_type(const char *type)
429{
430 int i;
431
432 if (!type)
433 type = DEFAULT_FETCH_TYPE_STR;
434
435 /* Special case: bitfield */
436 if (*type == 'b') {
437 unsigned long bs;
438
439 type = strchr(type, '/');
440 if (!type)
441 goto fail;
442
443 type++;
444 if (strict_strtoul(type, 0, &bs))
445 goto fail;
446
447 switch (bs) {
448 case 8:
449 return find_fetch_type("u8");
450 case 16:
451 return find_fetch_type("u16");
452 case 32:
453 return find_fetch_type("u32");
454 case 64:
455 return find_fetch_type("u64");
456 default:
457 goto fail;
458 }
459 }
460
461 for (i = 0; i < ARRAY_SIZE(fetch_type_table); i++)
462 if (strcmp(type, fetch_type_table[i].name) == 0)
463 return &fetch_type_table[i];
464
465fail:
466 return NULL;
467}
468
469/* Special function : only accept unsigned long */
470static __kprobes void fetch_stack_address(struct pt_regs *regs,
471 void *dummy, void *dest)
472{
473 *(unsigned long *)dest = kernel_stack_pointer(regs);
474}
475
476static fetch_func_t get_fetch_size_function(const struct fetch_type *type,
477 fetch_func_t orig_fn)
478{
479 int i;
480
481 if (type != &fetch_type_table[FETCH_TYPE_STRING])
482 return NULL; /* Only string type needs size function */
483
484 for (i = 0; i < FETCH_MTD_END; i++)
485 if (type->fetch[i] == orig_fn)
486 return fetch_type_table[FETCH_TYPE_STRSIZE].fetch[i];
487
488 WARN_ON(1); /* This should not happen */
489
490 return NULL;
491}
492
493/* Split symbol and offset. */
494int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset)
495{
496 char *tmp;
497 int ret;
498
499 if (!offset)
500 return -EINVAL;
501
502 tmp = strchr(symbol, '+');
503 if (tmp) {
504 /* skip sign because strict_strtol doesn't accept '+' */
505 ret = strict_strtoul(tmp + 1, 0, offset);
506 if (ret)
507 return ret;
508
509 *tmp = '\0';
510 } else
511 *offset = 0;
512
513 return 0;
514}
515
516#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
517
518static int parse_probe_vars(char *arg, const struct fetch_type *t,
519 struct fetch_param *f, bool is_return)
520{
521 int ret = 0;
522 unsigned long param;
523
524 if (strcmp(arg, "retval") == 0) {
525 if (is_return)
526 f->fn = t->fetch[FETCH_MTD_retval];
527 else
528 ret = -EINVAL;
529 } else if (strncmp(arg, "stack", 5) == 0) {
530 if (arg[5] == '\0') {
531 if (strcmp(t->name, DEFAULT_FETCH_TYPE_STR) == 0)
532 f->fn = fetch_stack_address;
533 else
534 ret = -EINVAL;
535 } else if (isdigit(arg[5])) {
536 ret = strict_strtoul(arg + 5, 10, ¶m);
537 if (ret || param > PARAM_MAX_STACK)
538 ret = -EINVAL;
539 else {
540 f->fn = t->fetch[FETCH_MTD_stack];
541 f->data = (void *)param;
542 }
543 } else
544 ret = -EINVAL;
545 } else
546 ret = -EINVAL;
547
548 return ret;
549}
550
551/* Recursive argument parser */
552static int parse_probe_arg(char *arg, const struct fetch_type *t,
553 struct fetch_param *f, bool is_return, bool is_kprobe)
554{
555 unsigned long param;
556 long offset;
557 char *tmp;
558 int ret;
559
560 ret = 0;
561
562 /* Until uprobe_events supports only reg arguments */
563 if (!is_kprobe && arg[0] != '%')
564 return -EINVAL;
565
566 switch (arg[0]) {
567 case '$':
568 ret = parse_probe_vars(arg + 1, t, f, is_return);
569 break;
570
571 case '%': /* named register */
572 ret = regs_query_register_offset(arg + 1);
573 if (ret >= 0) {
574 f->fn = t->fetch[FETCH_MTD_reg];
575 f->data = (void *)(unsigned long)ret;
576 ret = 0;
577 }
578 break;
579
580 case '@': /* memory or symbol */
581 if (isdigit(arg[1])) {
582 ret = strict_strtoul(arg + 1, 0, ¶m);
583 if (ret)
584 break;
585
586 f->fn = t->fetch[FETCH_MTD_memory];
587 f->data = (void *)param;
588 } else {
589 ret = traceprobe_split_symbol_offset(arg + 1, &offset);
590 if (ret)
591 break;
592
593 f->data = alloc_symbol_cache(arg + 1, offset);
594 if (f->data)
595 f->fn = t->fetch[FETCH_MTD_symbol];
596 }
597 break;
598
599 case '+': /* deref memory */
600 arg++; /* Skip '+', because strict_strtol() rejects it. */
601 case '-':
602 tmp = strchr(arg, '(');
603 if (!tmp)
604 break;
605
606 *tmp = '\0';
607 ret = strict_strtol(arg, 0, &offset);
608
609 if (ret)
610 break;
611
612 arg = tmp + 1;
613 tmp = strrchr(arg, ')');
614
615 if (tmp) {
616 struct deref_fetch_param *dprm;
617 const struct fetch_type *t2;
618
619 t2 = find_fetch_type(NULL);
620 *tmp = '\0';
621 dprm = kzalloc(sizeof(struct deref_fetch_param), GFP_KERNEL);
622
623 if (!dprm)
624 return -ENOMEM;
625
626 dprm->offset = offset;
627 ret = parse_probe_arg(arg, t2, &dprm->orig, is_return,
628 is_kprobe);
629 if (ret)
630 kfree(dprm);
631 else {
632 f->fn = t->fetch[FETCH_MTD_deref];
633 f->data = (void *)dprm;
634 }
635 }
636 break;
637 }
638 if (!ret && !f->fn) { /* Parsed, but do not find fetch method */
639 pr_info("%s type has no corresponding fetch method.\n", t->name);
640 ret = -EINVAL;
641 }
642
643 return ret;
644}
645
646#define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long))
647
648/* Bitfield type needs to be parsed into a fetch function */
649static int __parse_bitfield_probe_arg(const char *bf,
650 const struct fetch_type *t,
651 struct fetch_param *f)
652{
653 struct bitfield_fetch_param *bprm;
654 unsigned long bw, bo;
655 char *tail;
656
657 if (*bf != 'b')
658 return 0;
659
660 bprm = kzalloc(sizeof(*bprm), GFP_KERNEL);
661 if (!bprm)
662 return -ENOMEM;
663
664 bprm->orig = *f;
665 f->fn = t->fetch[FETCH_MTD_bitfield];
666 f->data = (void *)bprm;
667 bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */
668
669 if (bw == 0 || *tail != '@')
670 return -EINVAL;
671
672 bf = tail + 1;
673 bo = simple_strtoul(bf, &tail, 0);
674
675 if (tail == bf || *tail != '/')
676 return -EINVAL;
677
678 bprm->hi_shift = BYTES_TO_BITS(t->size) - (bw + bo);
679 bprm->low_shift = bprm->hi_shift + bo;
680
681 return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0;
682}
683
684/* String length checking wrapper */
685int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
686 struct probe_arg *parg, bool is_return, bool is_kprobe)
687{
688 const char *t;
689 int ret;
690
691 if (strlen(arg) > MAX_ARGSTR_LEN) {
692 pr_info("Argument is too long.: %s\n", arg);
693 return -ENOSPC;
694 }
695 parg->comm = kstrdup(arg, GFP_KERNEL);
696 if (!parg->comm) {
697 pr_info("Failed to allocate memory for command '%s'.\n", arg);
698 return -ENOMEM;
699 }
700 t = strchr(parg->comm, ':');
701 if (t) {
702 arg[t - parg->comm] = '\0';
703 t++;
704 }
705 parg->type = find_fetch_type(t);
706 if (!parg->type) {
707 pr_info("Unsupported type: %s\n", t);
708 return -EINVAL;
709 }
710 parg->offset = *size;
711 *size += parg->type->size;
712 ret = parse_probe_arg(arg, parg->type, &parg->fetch, is_return, is_kprobe);
713
714 if (ret >= 0 && t != NULL)
715 ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch);
716
717 if (ret >= 0) {
718 parg->fetch_size.fn = get_fetch_size_function(parg->type,
719 parg->fetch.fn);
720 parg->fetch_size.data = parg->fetch.data;
721 }
722
723 return ret;
724}
725
726/* Return 1 if name is reserved or already used by another argument */
727int traceprobe_conflict_field_name(const char *name,
728 struct probe_arg *args, int narg)
729{
730 int i;
731
732 for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++)
733 if (strcmp(reserved_field_names[i], name) == 0)
734 return 1;
735
736 for (i = 0; i < narg; i++)
737 if (strcmp(args[i].name, name) == 0)
738 return 1;
739
740 return 0;
741}
742
743void traceprobe_update_arg(struct probe_arg *arg)
744{
745 if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))
746 update_bitfield_fetch_param(arg->fetch.data);
747 else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
748 update_deref_fetch_param(arg->fetch.data);
749 else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn))
750 update_symbol_cache(arg->fetch.data);
751}
752
753void traceprobe_free_probe_arg(struct probe_arg *arg)
754{
755 if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))
756 free_bitfield_fetch_param(arg->fetch.data);
757 else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
758 free_deref_fetch_param(arg->fetch.data);
759 else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn))
760 free_symbol_cache(arg->fetch.data);
761
762 kfree(arg->name);
763 kfree(arg->comm);
764}
765
766int traceprobe_command(const char *buf, int (*createfn)(int, char **))
767{
768 char **argv;
769 int argc, ret;
770
771 argc = 0;
772 ret = 0;
773 argv = argv_split(GFP_KERNEL, buf, &argc);
774 if (!argv)
775 return -ENOMEM;
776
777 if (argc)
778 ret = createfn(argc, argv);
779
780 argv_free(argv);
781
782 return ret;
783}
784
785#define WRITE_BUFSIZE 4096
786
787ssize_t traceprobe_probes_write(struct file *file, const char __user *buffer,
788 size_t count, loff_t *ppos,
789 int (*createfn)(int, char **))
790{
791 char *kbuf, *tmp;
792 int ret = 0;
793 size_t done = 0;
794 size_t size;
795
796 kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL);
797 if (!kbuf)
798 return -ENOMEM;
799
800 while (done < count) {
801 size = count - done;
802
803 if (size >= WRITE_BUFSIZE)
804 size = WRITE_BUFSIZE - 1;
805
806 if (copy_from_user(kbuf, buffer + done, size)) {
807 ret = -EFAULT;
808 goto out;
809 }
810 kbuf[size] = '\0';
811 tmp = strchr(kbuf, '\n');
812
813 if (tmp) {
814 *tmp = '\0';
815 size = tmp - kbuf + 1;
816 } else if (done + size < count) {
817 pr_warning("Line length is too long: "
818 "Should be less than %d.", WRITE_BUFSIZE);
819 ret = -EINVAL;
820 goto out;
821 }
822 done += size;
823 /* Remove comments */
824 tmp = strchr(kbuf, '#');
825
826 if (tmp)
827 *tmp = '\0';
828
829 ret = traceprobe_command(kbuf, createfn);
830 if (ret)
831 goto out;
832 }
833 ret = done;
834
835out:
836 kfree(kbuf);
837
838 return ret;
839}
1/*
2 * Common code for probe-based Dynamic events.
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License
14 * along with this program; if not, write to the Free Software
15 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
16 *
17 * This code was copied from kernel/trace/trace_kprobe.c written by
18 * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
19 *
20 * Updates to make this generic:
21 * Copyright (C) IBM Corporation, 2010-2011
22 * Author: Srikar Dronamraju
23 */
24
25#include "trace_probe.h"
26
27const char *reserved_field_names[] = {
28 "common_type",
29 "common_flags",
30 "common_preempt_count",
31 "common_pid",
32 "common_tgid",
33 FIELD_STRING_IP,
34 FIELD_STRING_RETIP,
35 FIELD_STRING_FUNC,
36};
37
38/* Printing in basic type function template */
39#define DEFINE_BASIC_PRINT_TYPE_FUNC(tname, type, fmt) \
40int PRINT_TYPE_FUNC_NAME(tname)(struct trace_seq *s, const char *name, \
41 void *data, void *ent) \
42{ \
43 trace_seq_printf(s, " %s=" fmt, name, *(type *)data); \
44 return !trace_seq_has_overflowed(s); \
45} \
46const char PRINT_TYPE_FMT_NAME(tname)[] = fmt; \
47NOKPROBE_SYMBOL(PRINT_TYPE_FUNC_NAME(tname));
48
49DEFINE_BASIC_PRINT_TYPE_FUNC(u8, u8, "%u")
50DEFINE_BASIC_PRINT_TYPE_FUNC(u16, u16, "%u")
51DEFINE_BASIC_PRINT_TYPE_FUNC(u32, u32, "%u")
52DEFINE_BASIC_PRINT_TYPE_FUNC(u64, u64, "%Lu")
53DEFINE_BASIC_PRINT_TYPE_FUNC(s8, s8, "%d")
54DEFINE_BASIC_PRINT_TYPE_FUNC(s16, s16, "%d")
55DEFINE_BASIC_PRINT_TYPE_FUNC(s32, s32, "%d")
56DEFINE_BASIC_PRINT_TYPE_FUNC(s64, s64, "%Ld")
57DEFINE_BASIC_PRINT_TYPE_FUNC(x8, u8, "0x%x")
58DEFINE_BASIC_PRINT_TYPE_FUNC(x16, u16, "0x%x")
59DEFINE_BASIC_PRINT_TYPE_FUNC(x32, u32, "0x%x")
60DEFINE_BASIC_PRINT_TYPE_FUNC(x64, u64, "0x%Lx")
61
62/* Print type function for string type */
63int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, const char *name,
64 void *data, void *ent)
65{
66 int len = *(u32 *)data >> 16;
67
68 if (!len)
69 trace_seq_printf(s, " %s=(fault)", name);
70 else
71 trace_seq_printf(s, " %s=\"%s\"", name,
72 (const char *)get_loc_data(data, ent));
73 return !trace_seq_has_overflowed(s);
74}
75NOKPROBE_SYMBOL(PRINT_TYPE_FUNC_NAME(string));
76
77const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\"";
78
79#define CHECK_FETCH_FUNCS(method, fn) \
80 (((FETCH_FUNC_NAME(method, u8) == fn) || \
81 (FETCH_FUNC_NAME(method, u16) == fn) || \
82 (FETCH_FUNC_NAME(method, u32) == fn) || \
83 (FETCH_FUNC_NAME(method, u64) == fn) || \
84 (FETCH_FUNC_NAME(method, string) == fn) || \
85 (FETCH_FUNC_NAME(method, string_size) == fn)) \
86 && (fn != NULL))
87
88/* Data fetch function templates */
89#define DEFINE_FETCH_reg(type) \
90void FETCH_FUNC_NAME(reg, type)(struct pt_regs *regs, void *offset, void *dest) \
91{ \
92 *(type *)dest = (type)regs_get_register(regs, \
93 (unsigned int)((unsigned long)offset)); \
94} \
95NOKPROBE_SYMBOL(FETCH_FUNC_NAME(reg, type));
96DEFINE_BASIC_FETCH_FUNCS(reg)
97/* No string on the register */
98#define fetch_reg_string NULL
99#define fetch_reg_string_size NULL
100
101#define DEFINE_FETCH_retval(type) \
102void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs, \
103 void *dummy, void *dest) \
104{ \
105 *(type *)dest = (type)regs_return_value(regs); \
106} \
107NOKPROBE_SYMBOL(FETCH_FUNC_NAME(retval, type));
108DEFINE_BASIC_FETCH_FUNCS(retval)
109/* No string on the retval */
110#define fetch_retval_string NULL
111#define fetch_retval_string_size NULL
112
113/* Dereference memory access function */
114struct deref_fetch_param {
115 struct fetch_param orig;
116 long offset;
117 fetch_func_t fetch;
118 fetch_func_t fetch_size;
119};
120
121#define DEFINE_FETCH_deref(type) \
122void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs, \
123 void *data, void *dest) \
124{ \
125 struct deref_fetch_param *dprm = data; \
126 unsigned long addr; \
127 call_fetch(&dprm->orig, regs, &addr); \
128 if (addr) { \
129 addr += dprm->offset; \
130 dprm->fetch(regs, (void *)addr, dest); \
131 } else \
132 *(type *)dest = 0; \
133} \
134NOKPROBE_SYMBOL(FETCH_FUNC_NAME(deref, type));
135DEFINE_BASIC_FETCH_FUNCS(deref)
136DEFINE_FETCH_deref(string)
137
138void FETCH_FUNC_NAME(deref, string_size)(struct pt_regs *regs,
139 void *data, void *dest)
140{
141 struct deref_fetch_param *dprm = data;
142 unsigned long addr;
143
144 call_fetch(&dprm->orig, regs, &addr);
145 if (addr && dprm->fetch_size) {
146 addr += dprm->offset;
147 dprm->fetch_size(regs, (void *)addr, dest);
148 } else
149 *(string_size *)dest = 0;
150}
151NOKPROBE_SYMBOL(FETCH_FUNC_NAME(deref, string_size));
152
153static void update_deref_fetch_param(struct deref_fetch_param *data)
154{
155 if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
156 update_deref_fetch_param(data->orig.data);
157 else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
158 update_symbol_cache(data->orig.data);
159}
160NOKPROBE_SYMBOL(update_deref_fetch_param);
161
162static void free_deref_fetch_param(struct deref_fetch_param *data)
163{
164 if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
165 free_deref_fetch_param(data->orig.data);
166 else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
167 free_symbol_cache(data->orig.data);
168 kfree(data);
169}
170NOKPROBE_SYMBOL(free_deref_fetch_param);
171
172/* Bitfield fetch function */
173struct bitfield_fetch_param {
174 struct fetch_param orig;
175 unsigned char hi_shift;
176 unsigned char low_shift;
177};
178
179#define DEFINE_FETCH_bitfield(type) \
180void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs, \
181 void *data, void *dest) \
182{ \
183 struct bitfield_fetch_param *bprm = data; \
184 type buf = 0; \
185 call_fetch(&bprm->orig, regs, &buf); \
186 if (buf) { \
187 buf <<= bprm->hi_shift; \
188 buf >>= bprm->low_shift; \
189 } \
190 *(type *)dest = buf; \
191} \
192NOKPROBE_SYMBOL(FETCH_FUNC_NAME(bitfield, type));
193DEFINE_BASIC_FETCH_FUNCS(bitfield)
194#define fetch_bitfield_string NULL
195#define fetch_bitfield_string_size NULL
196
197static void
198update_bitfield_fetch_param(struct bitfield_fetch_param *data)
199{
200 /*
201 * Don't check the bitfield itself, because this must be the
202 * last fetch function.
203 */
204 if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
205 update_deref_fetch_param(data->orig.data);
206 else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
207 update_symbol_cache(data->orig.data);
208}
209
210static void
211free_bitfield_fetch_param(struct bitfield_fetch_param *data)
212{
213 /*
214 * Don't check the bitfield itself, because this must be the
215 * last fetch function.
216 */
217 if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
218 free_deref_fetch_param(data->orig.data);
219 else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
220 free_symbol_cache(data->orig.data);
221
222 kfree(data);
223}
224
225void FETCH_FUNC_NAME(comm, string)(struct pt_regs *regs,
226 void *data, void *dest)
227{
228 int maxlen = get_rloc_len(*(u32 *)dest);
229 u8 *dst = get_rloc_data(dest);
230 long ret;
231
232 if (!maxlen)
233 return;
234
235 ret = strlcpy(dst, current->comm, maxlen);
236 *(u32 *)dest = make_data_rloc(ret, get_rloc_offs(*(u32 *)dest));
237}
238NOKPROBE_SYMBOL(FETCH_FUNC_NAME(comm, string));
239
240void FETCH_FUNC_NAME(comm, string_size)(struct pt_regs *regs,
241 void *data, void *dest)
242{
243 *(u32 *)dest = strlen(current->comm) + 1;
244}
245NOKPROBE_SYMBOL(FETCH_FUNC_NAME(comm, string_size));
246
247static const struct fetch_type *find_fetch_type(const char *type,
248 const struct fetch_type *ftbl)
249{
250 int i;
251
252 if (!type)
253 type = DEFAULT_FETCH_TYPE_STR;
254
255 /* Special case: bitfield */
256 if (*type == 'b') {
257 unsigned long bs;
258
259 type = strchr(type, '/');
260 if (!type)
261 goto fail;
262
263 type++;
264 if (kstrtoul(type, 0, &bs))
265 goto fail;
266
267 switch (bs) {
268 case 8:
269 return find_fetch_type("u8", ftbl);
270 case 16:
271 return find_fetch_type("u16", ftbl);
272 case 32:
273 return find_fetch_type("u32", ftbl);
274 case 64:
275 return find_fetch_type("u64", ftbl);
276 default:
277 goto fail;
278 }
279 }
280
281 for (i = 0; ftbl[i].name; i++) {
282 if (strcmp(type, ftbl[i].name) == 0)
283 return &ftbl[i];
284 }
285
286fail:
287 return NULL;
288}
289
290/* Special function : only accept unsigned long */
291static void fetch_kernel_stack_address(struct pt_regs *regs, void *dummy, void *dest)
292{
293 *(unsigned long *)dest = kernel_stack_pointer(regs);
294}
295NOKPROBE_SYMBOL(fetch_kernel_stack_address);
296
297static void fetch_user_stack_address(struct pt_regs *regs, void *dummy, void *dest)
298{
299 *(unsigned long *)dest = user_stack_pointer(regs);
300}
301NOKPROBE_SYMBOL(fetch_user_stack_address);
302
303static fetch_func_t get_fetch_size_function(const struct fetch_type *type,
304 fetch_func_t orig_fn,
305 const struct fetch_type *ftbl)
306{
307 int i;
308
309 if (type != &ftbl[FETCH_TYPE_STRING])
310 return NULL; /* Only string type needs size function */
311
312 for (i = 0; i < FETCH_MTD_END; i++)
313 if (type->fetch[i] == orig_fn)
314 return ftbl[FETCH_TYPE_STRSIZE].fetch[i];
315
316 WARN_ON(1); /* This should not happen */
317
318 return NULL;
319}
320
321/* Split symbol and offset. */
322int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset)
323{
324 char *tmp;
325 int ret;
326
327 if (!offset)
328 return -EINVAL;
329
330 tmp = strchr(symbol, '+');
331 if (tmp) {
332 /* skip sign because kstrtoul doesn't accept '+' */
333 ret = kstrtoul(tmp + 1, 0, offset);
334 if (ret)
335 return ret;
336
337 *tmp = '\0';
338 } else
339 *offset = 0;
340
341 return 0;
342}
343
344#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
345
346static int parse_probe_vars(char *arg, const struct fetch_type *t,
347 struct fetch_param *f, bool is_return,
348 bool is_kprobe)
349{
350 int ret = 0;
351 unsigned long param;
352
353 if (strcmp(arg, "retval") == 0) {
354 if (is_return)
355 f->fn = t->fetch[FETCH_MTD_retval];
356 else
357 ret = -EINVAL;
358 } else if (strncmp(arg, "stack", 5) == 0) {
359 if (arg[5] == '\0') {
360 if (strcmp(t->name, DEFAULT_FETCH_TYPE_STR))
361 return -EINVAL;
362
363 if (is_kprobe)
364 f->fn = fetch_kernel_stack_address;
365 else
366 f->fn = fetch_user_stack_address;
367 } else if (isdigit(arg[5])) {
368 ret = kstrtoul(arg + 5, 10, ¶m);
369 if (ret || (is_kprobe && param > PARAM_MAX_STACK))
370 ret = -EINVAL;
371 else {
372 f->fn = t->fetch[FETCH_MTD_stack];
373 f->data = (void *)param;
374 }
375 } else
376 ret = -EINVAL;
377 } else if (strcmp(arg, "comm") == 0) {
378 if (strcmp(t->name, "string") != 0 &&
379 strcmp(t->name, "string_size") != 0)
380 return -EINVAL;
381 f->fn = t->fetch[FETCH_MTD_comm];
382 } else
383 ret = -EINVAL;
384
385 return ret;
386}
387
388/* Recursive argument parser */
389static int parse_probe_arg(char *arg, const struct fetch_type *t,
390 struct fetch_param *f, bool is_return, bool is_kprobe,
391 const struct fetch_type *ftbl)
392{
393 unsigned long param;
394 long offset;
395 char *tmp;
396 int ret = 0;
397
398 switch (arg[0]) {
399 case '$':
400 ret = parse_probe_vars(arg + 1, t, f, is_return, is_kprobe);
401 break;
402
403 case '%': /* named register */
404 ret = regs_query_register_offset(arg + 1);
405 if (ret >= 0) {
406 f->fn = t->fetch[FETCH_MTD_reg];
407 f->data = (void *)(unsigned long)ret;
408 ret = 0;
409 }
410 break;
411
412 case '@': /* memory, file-offset or symbol */
413 if (isdigit(arg[1])) {
414 ret = kstrtoul(arg + 1, 0, ¶m);
415 if (ret)
416 break;
417
418 f->fn = t->fetch[FETCH_MTD_memory];
419 f->data = (void *)param;
420 } else if (arg[1] == '+') {
421 /* kprobes don't support file offsets */
422 if (is_kprobe)
423 return -EINVAL;
424
425 ret = kstrtol(arg + 2, 0, &offset);
426 if (ret)
427 break;
428
429 f->fn = t->fetch[FETCH_MTD_file_offset];
430 f->data = (void *)offset;
431 } else {
432 /* uprobes don't support symbols */
433 if (!is_kprobe)
434 return -EINVAL;
435
436 ret = traceprobe_split_symbol_offset(arg + 1, &offset);
437 if (ret)
438 break;
439
440 f->data = alloc_symbol_cache(arg + 1, offset);
441 if (f->data)
442 f->fn = t->fetch[FETCH_MTD_symbol];
443 }
444 break;
445
446 case '+': /* deref memory */
447 arg++; /* Skip '+', because kstrtol() rejects it. */
448 case '-':
449 tmp = strchr(arg, '(');
450 if (!tmp)
451 break;
452
453 *tmp = '\0';
454 ret = kstrtol(arg, 0, &offset);
455
456 if (ret)
457 break;
458
459 arg = tmp + 1;
460 tmp = strrchr(arg, ')');
461
462 if (tmp) {
463 struct deref_fetch_param *dprm;
464 const struct fetch_type *t2;
465
466 t2 = find_fetch_type(NULL, ftbl);
467 *tmp = '\0';
468 dprm = kzalloc(sizeof(struct deref_fetch_param), GFP_KERNEL);
469
470 if (!dprm)
471 return -ENOMEM;
472
473 dprm->offset = offset;
474 dprm->fetch = t->fetch[FETCH_MTD_memory];
475 dprm->fetch_size = get_fetch_size_function(t,
476 dprm->fetch, ftbl);
477 ret = parse_probe_arg(arg, t2, &dprm->orig, is_return,
478 is_kprobe, ftbl);
479 if (ret)
480 kfree(dprm);
481 else {
482 f->fn = t->fetch[FETCH_MTD_deref];
483 f->data = (void *)dprm;
484 }
485 }
486 break;
487 }
488 if (!ret && !f->fn) { /* Parsed, but do not find fetch method */
489 pr_info("%s type has no corresponding fetch method.\n", t->name);
490 ret = -EINVAL;
491 }
492
493 return ret;
494}
495
496#define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long))
497
498/* Bitfield type needs to be parsed into a fetch function */
499static int __parse_bitfield_probe_arg(const char *bf,
500 const struct fetch_type *t,
501 struct fetch_param *f)
502{
503 struct bitfield_fetch_param *bprm;
504 unsigned long bw, bo;
505 char *tail;
506
507 if (*bf != 'b')
508 return 0;
509
510 bprm = kzalloc(sizeof(*bprm), GFP_KERNEL);
511 if (!bprm)
512 return -ENOMEM;
513
514 bprm->orig = *f;
515 f->fn = t->fetch[FETCH_MTD_bitfield];
516 f->data = (void *)bprm;
517 bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */
518
519 if (bw == 0 || *tail != '@')
520 return -EINVAL;
521
522 bf = tail + 1;
523 bo = simple_strtoul(bf, &tail, 0);
524
525 if (tail == bf || *tail != '/')
526 return -EINVAL;
527
528 bprm->hi_shift = BYTES_TO_BITS(t->size) - (bw + bo);
529 bprm->low_shift = bprm->hi_shift + bo;
530
531 return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0;
532}
533
534/* String length checking wrapper */
535int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
536 struct probe_arg *parg, bool is_return, bool is_kprobe,
537 const struct fetch_type *ftbl)
538{
539 const char *t;
540 int ret;
541
542 if (strlen(arg) > MAX_ARGSTR_LEN) {
543 pr_info("Argument is too long.: %s\n", arg);
544 return -ENOSPC;
545 }
546 parg->comm = kstrdup(arg, GFP_KERNEL);
547 if (!parg->comm) {
548 pr_info("Failed to allocate memory for command '%s'.\n", arg);
549 return -ENOMEM;
550 }
551 t = strchr(parg->comm, ':');
552 if (t) {
553 arg[t - parg->comm] = '\0';
554 t++;
555 }
556 /*
557 * The default type of $comm should be "string", and it can't be
558 * dereferenced.
559 */
560 if (!t && strcmp(arg, "$comm") == 0)
561 t = "string";
562 parg->type = find_fetch_type(t, ftbl);
563 if (!parg->type) {
564 pr_info("Unsupported type: %s\n", t);
565 return -EINVAL;
566 }
567 parg->offset = *size;
568 *size += parg->type->size;
569 ret = parse_probe_arg(arg, parg->type, &parg->fetch, is_return,
570 is_kprobe, ftbl);
571
572 if (ret >= 0 && t != NULL)
573 ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch);
574
575 if (ret >= 0) {
576 parg->fetch_size.fn = get_fetch_size_function(parg->type,
577 parg->fetch.fn,
578 ftbl);
579 parg->fetch_size.data = parg->fetch.data;
580 }
581
582 return ret;
583}
584
585/* Return 1 if name is reserved or already used by another argument */
586int traceprobe_conflict_field_name(const char *name,
587 struct probe_arg *args, int narg)
588{
589 int i;
590
591 for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++)
592 if (strcmp(reserved_field_names[i], name) == 0)
593 return 1;
594
595 for (i = 0; i < narg; i++)
596 if (strcmp(args[i].name, name) == 0)
597 return 1;
598
599 return 0;
600}
601
602void traceprobe_update_arg(struct probe_arg *arg)
603{
604 if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))
605 update_bitfield_fetch_param(arg->fetch.data);
606 else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
607 update_deref_fetch_param(arg->fetch.data);
608 else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn))
609 update_symbol_cache(arg->fetch.data);
610}
611
612void traceprobe_free_probe_arg(struct probe_arg *arg)
613{
614 if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))
615 free_bitfield_fetch_param(arg->fetch.data);
616 else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
617 free_deref_fetch_param(arg->fetch.data);
618 else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn))
619 free_symbol_cache(arg->fetch.data);
620
621 kfree(arg->name);
622 kfree(arg->comm);
623}
624
625int traceprobe_command(const char *buf, int (*createfn)(int, char **))
626{
627 char **argv;
628 int argc, ret;
629
630 argc = 0;
631 ret = 0;
632 argv = argv_split(GFP_KERNEL, buf, &argc);
633 if (!argv)
634 return -ENOMEM;
635
636 if (argc)
637 ret = createfn(argc, argv);
638
639 argv_free(argv);
640
641 return ret;
642}
643
644#define WRITE_BUFSIZE 4096
645
646ssize_t traceprobe_probes_write(struct file *file, const char __user *buffer,
647 size_t count, loff_t *ppos,
648 int (*createfn)(int, char **))
649{
650 char *kbuf, *tmp;
651 int ret = 0;
652 size_t done = 0;
653 size_t size;
654
655 kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL);
656 if (!kbuf)
657 return -ENOMEM;
658
659 while (done < count) {
660 size = count - done;
661
662 if (size >= WRITE_BUFSIZE)
663 size = WRITE_BUFSIZE - 1;
664
665 if (copy_from_user(kbuf, buffer + done, size)) {
666 ret = -EFAULT;
667 goto out;
668 }
669 kbuf[size] = '\0';
670 tmp = strchr(kbuf, '\n');
671
672 if (tmp) {
673 *tmp = '\0';
674 size = tmp - kbuf + 1;
675 } else if (done + size < count) {
676 pr_warn("Line length is too long: Should be less than %d\n",
677 WRITE_BUFSIZE);
678 ret = -EINVAL;
679 goto out;
680 }
681 done += size;
682 /* Remove comments */
683 tmp = strchr(kbuf, '#');
684
685 if (tmp)
686 *tmp = '\0';
687
688 ret = traceprobe_command(kbuf, createfn);
689 if (ret)
690 goto out;
691 }
692 ret = done;
693
694out:
695 kfree(kbuf);
696
697 return ret;
698}
699
700static int __set_print_fmt(struct trace_probe *tp, char *buf, int len,
701 bool is_return)
702{
703 int i;
704 int pos = 0;
705
706 const char *fmt, *arg;
707
708 if (!is_return) {
709 fmt = "(%lx)";
710 arg = "REC->" FIELD_STRING_IP;
711 } else {
712 fmt = "(%lx <- %lx)";
713 arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP;
714 }
715
716 /* When len=0, we just calculate the needed length */
717#define LEN_OR_ZERO (len ? len - pos : 0)
718
719 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt);
720
721 for (i = 0; i < tp->nr_args; i++) {
722 pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%s",
723 tp->args[i].name, tp->args[i].type->fmt);
724 }
725
726 pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg);
727
728 for (i = 0; i < tp->nr_args; i++) {
729 if (strcmp(tp->args[i].type->name, "string") == 0)
730 pos += snprintf(buf + pos, LEN_OR_ZERO,
731 ", __get_str(%s)",
732 tp->args[i].name);
733 else
734 pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s",
735 tp->args[i].name);
736 }
737
738#undef LEN_OR_ZERO
739
740 /* return the length of print_fmt */
741 return pos;
742}
743
744int set_print_fmt(struct trace_probe *tp, bool is_return)
745{
746 int len;
747 char *print_fmt;
748
749 /* First: called with 0 length to calculate the needed length */
750 len = __set_print_fmt(tp, NULL, 0, is_return);
751 print_fmt = kmalloc(len + 1, GFP_KERNEL);
752 if (!print_fmt)
753 return -ENOMEM;
754
755 /* Second: actually write the @print_fmt */
756 __set_print_fmt(tp, print_fmt, len + 1, is_return);
757 tp->call.print_fmt = print_fmt;
758
759 return 0;
760}