]> git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blame - kernel/trace/trace_probe.h
Merge remote-tracking branch 'mkp-scsi/4.8/scsi-fixes' into fixes
[mirror_ubuntu-artful-kernel.git] / kernel / trace / trace_probe.h
CommitLineData
8ab83f56
SD
1/*
2 * Common header file 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.h 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 <linux/seq_file.h>
26#include <linux/slab.h>
27#include <linux/smp.h>
8434dc93 28#include <linux/tracefs.h>
8ab83f56
SD
29#include <linux/types.h>
30#include <linux/string.h>
31#include <linux/ctype.h>
32#include <linux/ptrace.h>
33#include <linux/perf_event.h>
34#include <linux/kprobes.h>
35#include <linux/stringify.h>
36#include <linux/limits.h>
37#include <linux/uaccess.h>
38#include <asm/bitsperlong.h>
39
40#include "trace.h"
41#include "trace_output.h"
42
43#define MAX_TRACE_ARGS 128
44#define MAX_ARGSTR_LEN 63
45#define MAX_EVENT_NAME_LEN 64
46#define MAX_STRING_SIZE PATH_MAX
47
48/* Reserved field names */
49#define FIELD_STRING_IP "__probe_ip"
50#define FIELD_STRING_RETIP "__probe_ret_ip"
51#define FIELD_STRING_FUNC "__probe_func"
52
53#undef DEFINE_FIELD
54#define DEFINE_FIELD(type, item, name, is_signed) \
55 do { \
56 ret = trace_define_field(event_call, #type, name, \
57 offsetof(typeof(field), item), \
58 sizeof(field.item), is_signed, \
59 FILTER_OTHER); \
60 if (ret) \
61 return ret; \
62 } while (0)
63
64
65/* Flags for trace_probe */
66#define TP_FLAG_TRACE 1
67#define TP_FLAG_PROFILE 2
68#define TP_FLAG_REGISTERED 4
69
70
71/* data_rloc: data relative location, compatible with u32 */
72#define make_data_rloc(len, roffs) \
73 (((u32)(len) << 16) | ((u32)(roffs) & 0xffff))
74#define get_rloc_len(dl) ((u32)(dl) >> 16)
75#define get_rloc_offs(dl) ((u32)(dl) & 0xffff)
76
77/*
78 * Convert data_rloc to data_loc:
79 * data_rloc stores the offset from data_rloc itself, but data_loc
80 * stores the offset from event entry.
81 */
82#define convert_rloc_to_loc(dl, offs) ((u32)(dl) + (offs))
83
3da0f180 84static nokprobe_inline void *get_rloc_data(u32 *dl)
b26c74e1
NK
85{
86 return (u8 *)dl + get_rloc_offs(*dl);
87}
88
89/* For data_loc conversion */
3da0f180 90static nokprobe_inline void *get_loc_data(u32 *dl, void *ent)
b26c74e1
NK
91{
92 return (u8 *)ent + get_rloc_offs(*dl);
93}
94
8ab83f56
SD
95/* Data fetch function type */
96typedef void (*fetch_func_t)(struct pt_regs *, void *, void *);
97/* Printing function type */
98typedef int (*print_type_func_t)(struct trace_seq *, const char *, void *, void *);
99
100/* Fetch types */
101enum {
102 FETCH_MTD_reg = 0,
103 FETCH_MTD_stack,
104 FETCH_MTD_retval,
35abb67d 105 FETCH_MTD_comm,
8ab83f56
SD
106 FETCH_MTD_memory,
107 FETCH_MTD_symbol,
108 FETCH_MTD_deref,
109 FETCH_MTD_bitfield,
b7e0bf34 110 FETCH_MTD_file_offset,
8ab83f56
SD
111 FETCH_MTD_END,
112};
113
114/* Fetch type information table */
115struct fetch_type {
116 const char *name; /* Name of type */
117 size_t size; /* Byte size of type */
118 int is_signed; /* Signed flag */
119 print_type_func_t print; /* Print functions */
120 const char *fmt; /* Fromat string */
121 const char *fmttype; /* Name in format file */
122 /* Fetch functions */
123 fetch_func_t fetch[FETCH_MTD_END];
124};
125
126struct fetch_param {
127 fetch_func_t fn;
128 void *data;
129};
130
34fee3a1
NK
131/* For defining macros, define string/string_size types */
132typedef u32 string;
133typedef u32 string_size;
134
b26c74e1
NK
135#define PRINT_TYPE_FUNC_NAME(type) print_type_##type
136#define PRINT_TYPE_FMT_NAME(type) print_type_format_##type
137
138/* Printing in basic type function template */
139#define DECLARE_BASIC_PRINT_TYPE_FUNC(type) \
3da0f180
MH
140int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, const char *name, \
141 void *data, void *ent); \
b26c74e1
NK
142extern const char PRINT_TYPE_FMT_NAME(type)[]
143
144DECLARE_BASIC_PRINT_TYPE_FUNC(u8);
145DECLARE_BASIC_PRINT_TYPE_FUNC(u16);
146DECLARE_BASIC_PRINT_TYPE_FUNC(u32);
147DECLARE_BASIC_PRINT_TYPE_FUNC(u64);
148DECLARE_BASIC_PRINT_TYPE_FUNC(s8);
149DECLARE_BASIC_PRINT_TYPE_FUNC(s16);
150DECLARE_BASIC_PRINT_TYPE_FUNC(s32);
151DECLARE_BASIC_PRINT_TYPE_FUNC(s64);
152DECLARE_BASIC_PRINT_TYPE_FUNC(string);
153
34fee3a1
NK
154#define FETCH_FUNC_NAME(method, type) fetch_##method##_##type
155
156/* Declare macro for basic types */
157#define DECLARE_FETCH_FUNC(method, type) \
158extern void FETCH_FUNC_NAME(method, type)(struct pt_regs *regs, \
159 void *data, void *dest)
160
161#define DECLARE_BASIC_FETCH_FUNCS(method) \
162DECLARE_FETCH_FUNC(method, u8); \
163DECLARE_FETCH_FUNC(method, u16); \
164DECLARE_FETCH_FUNC(method, u32); \
165DECLARE_FETCH_FUNC(method, u64)
166
167DECLARE_BASIC_FETCH_FUNCS(reg);
168#define fetch_reg_string NULL
169#define fetch_reg_string_size NULL
170
34fee3a1
NK
171DECLARE_BASIC_FETCH_FUNCS(retval);
172#define fetch_retval_string NULL
173#define fetch_retval_string_size NULL
174
34fee3a1
NK
175DECLARE_BASIC_FETCH_FUNCS(symbol);
176DECLARE_FETCH_FUNC(symbol, string);
177DECLARE_FETCH_FUNC(symbol, string_size);
178
179DECLARE_BASIC_FETCH_FUNCS(deref);
180DECLARE_FETCH_FUNC(deref, string);
181DECLARE_FETCH_FUNC(deref, string_size);
182
183DECLARE_BASIC_FETCH_FUNCS(bitfield);
184#define fetch_bitfield_string NULL
185#define fetch_bitfield_string_size NULL
186
35abb67d
OS
187/* comm only makes sense as a string */
188#define fetch_comm_u8 NULL
189#define fetch_comm_u16 NULL
190#define fetch_comm_u32 NULL
191#define fetch_comm_u64 NULL
192DECLARE_FETCH_FUNC(comm, string);
193DECLARE_FETCH_FUNC(comm, string_size);
194
3fd996a2
NK
195/*
196 * Define macro for basic types - we don't need to define s* types, because
197 * we have to care only about bitwidth at recording time.
198 */
199#define DEFINE_BASIC_FETCH_FUNCS(method) \
200DEFINE_FETCH_##method(u8) \
201DEFINE_FETCH_##method(u16) \
202DEFINE_FETCH_##method(u32) \
203DEFINE_FETCH_##method(u64)
204
b26c74e1
NK
205/* Default (unsigned long) fetch type */
206#define __DEFAULT_FETCH_TYPE(t) u##t
207#define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t)
208#define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG)
209#define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE)
210
211#define ASSIGN_FETCH_FUNC(method, type) \
212 [FETCH_MTD_##method] = FETCH_FUNC_NAME(method, type)
213
214#define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \
215 {.name = _name, \
216 .size = _size, \
217 .is_signed = sign, \
218 .print = PRINT_TYPE_FUNC_NAME(ptype), \
219 .fmt = PRINT_TYPE_FMT_NAME(ptype), \
220 .fmttype = _fmttype, \
221 .fetch = { \
222ASSIGN_FETCH_FUNC(reg, ftype), \
223ASSIGN_FETCH_FUNC(stack, ftype), \
224ASSIGN_FETCH_FUNC(retval, ftype), \
35abb67d 225ASSIGN_FETCH_FUNC(comm, ftype), \
b26c74e1
NK
226ASSIGN_FETCH_FUNC(memory, ftype), \
227ASSIGN_FETCH_FUNC(symbol, ftype), \
228ASSIGN_FETCH_FUNC(deref, ftype), \
229ASSIGN_FETCH_FUNC(bitfield, ftype), \
b7e0bf34 230ASSIGN_FETCH_FUNC(file_offset, ftype), \
b26c74e1
NK
231 } \
232 }
233
234#define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \
235 __ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #ptype)
236
34fee3a1
NK
237#define ASSIGN_FETCH_TYPE_END {}
238
b26c74e1
NK
239#define FETCH_TYPE_STRING 0
240#define FETCH_TYPE_STRSIZE 1
241
1301a44e
NK
242#ifdef CONFIG_KPROBE_EVENT
243struct symbol_cache;
244unsigned long update_symbol_cache(struct symbol_cache *sc);
245void free_symbol_cache(struct symbol_cache *sc);
246struct symbol_cache *alloc_symbol_cache(const char *sym, long offset);
247#else
e0d18fe0
NK
248/* uprobes do not support symbol fetch methods */
249#define fetch_symbol_u8 NULL
250#define fetch_symbol_u16 NULL
251#define fetch_symbol_u32 NULL
252#define fetch_symbol_u64 NULL
253#define fetch_symbol_string NULL
254#define fetch_symbol_string_size NULL
255
1301a44e
NK
256struct symbol_cache {
257};
258static inline unsigned long __used update_symbol_cache(struct symbol_cache *sc)
259{
260 return 0;
261}
262
263static inline void __used free_symbol_cache(struct symbol_cache *sc)
264{
265}
266
267static inline struct symbol_cache * __used
268alloc_symbol_cache(const char *sym, long offset)
269{
270 return NULL;
271}
272#endif /* CONFIG_KPROBE_EVENT */
273
8ab83f56
SD
274struct probe_arg {
275 struct fetch_param fetch;
276 struct fetch_param fetch_size;
277 unsigned int offset; /* Offset from argument entry */
278 const char *name; /* Name of this argument */
279 const char *comm; /* Command of this argument */
280 const struct fetch_type *type; /* Type of this argument */
281};
282
c31ffb3f
NK
283struct trace_probe {
284 unsigned int flags; /* For TP_FLAG_* */
2425bcb9
SRRH
285 struct trace_event_class class;
286 struct trace_event_call call;
c31ffb3f
NK
287 struct list_head files;
288 ssize_t size; /* trace entry size */
289 unsigned int nr_args;
290 struct probe_arg args[];
291};
292
70ed91c6 293struct event_file_link {
7f1d2f82 294 struct trace_event_file *file;
70ed91c6
J
295 struct list_head list;
296};
297
c31ffb3f
NK
298static inline bool trace_probe_is_enabled(struct trace_probe *tp)
299{
300 return !!(tp->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE));
301}
302
303static inline bool trace_probe_is_registered(struct trace_probe *tp)
304{
305 return !!(tp->flags & TP_FLAG_REGISTERED);
306}
307
3da0f180 308static nokprobe_inline void call_fetch(struct fetch_param *fprm,
8ab83f56
SD
309 struct pt_regs *regs, void *dest)
310{
311 return fprm->fn(regs, fprm->data, dest);
312}
313
314/* Check the name is good for event/group/fields */
f0132c4e 315static inline bool is_good_name(const char *name)
8ab83f56
SD
316{
317 if (!isalpha(*name) && *name != '_')
f0132c4e 318 return false;
8ab83f56
SD
319 while (*++name != '\0') {
320 if (!isalpha(*name) && !isdigit(*name) && *name != '_')
f0132c4e 321 return false;
8ab83f56 322 }
f0132c4e 323 return true;
8ab83f56
SD
324}
325
70ed91c6 326static inline struct event_file_link *
7f1d2f82 327find_event_file_link(struct trace_probe *tp, struct trace_event_file *file)
70ed91c6
J
328{
329 struct event_file_link *link;
330
331 list_for_each_entry(link, &tp->files, list)
332 if (link->file == file)
333 return link;
334
335 return NULL;
336}
337
8ab83f56 338extern int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
d9a16d3a
SR
339 struct probe_arg *parg, bool is_return, bool is_kprobe,
340 const struct fetch_type *ftbl);
8ab83f56
SD
341
342extern int traceprobe_conflict_field_name(const char *name,
343 struct probe_arg *args, int narg);
344
345extern void traceprobe_update_arg(struct probe_arg *arg);
346extern void traceprobe_free_probe_arg(struct probe_arg *arg);
347
348extern int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset);
349
350extern ssize_t traceprobe_probes_write(struct file *file,
351 const char __user *buffer, size_t count, loff_t *ppos,
352 int (*createfn)(int, char**));
353
354extern int traceprobe_command(const char *buf, int (*createfn)(int, char**));
2dc10183
NK
355
356/* Sum up total data length for dynamic arraies (strings) */
3da0f180 357static nokprobe_inline int
2dc10183
NK
358__get_data_size(struct trace_probe *tp, struct pt_regs *regs)
359{
360 int i, ret = 0;
361 u32 len;
362
363 for (i = 0; i < tp->nr_args; i++)
364 if (unlikely(tp->args[i].fetch_size.fn)) {
365 call_fetch(&tp->args[i].fetch_size, regs, &len);
366 ret += len;
367 }
368
369 return ret;
370}
371
372/* Store the value of each argument */
3da0f180 373static nokprobe_inline void
2dc10183
NK
374store_trace_args(int ent_size, struct trace_probe *tp, struct pt_regs *regs,
375 u8 *data, int maxlen)
376{
377 int i;
378 u32 end = tp->size;
379 u32 *dl; /* Data (relative) location */
380
381 for (i = 0; i < tp->nr_args; i++) {
382 if (unlikely(tp->args[i].fetch_size.fn)) {
383 /*
384 * First, we set the relative location and
385 * maximum data length to *dl
386 */
387 dl = (u32 *)(data + tp->args[i].offset);
388 *dl = make_data_rloc(maxlen, end - tp->args[i].offset);
389 /* Then try to fetch string or dynamic array data */
390 call_fetch(&tp->args[i].fetch, regs, dl);
391 /* Reduce maximum length */
392 end += get_rloc_len(*dl);
393 maxlen -= get_rloc_len(*dl);
394 /* Trick here, convert data_rloc to data_loc */
395 *dl = convert_rloc_to_loc(*dl,
396 ent_size + tp->args[i].offset);
397 } else
398 /* Just fetching data normally */
399 call_fetch(&tp->args[i].fetch, regs,
400 data + tp->args[i].offset);
401 }
402}
5bf652aa
NK
403
404extern int set_print_fmt(struct trace_probe *tp, bool is_return);