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1/*
2 * Copyright (C) 2009 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
3 *
4 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation;
8 * version 2.1 of the License (not later!)
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 Lesser General Public License for more details.
14 *
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this program; if not, see <http://www.gnu.org/licenses>
17 *
18 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
19 */
20#include <stdio.h>
21#include <stdlib.h>
22#include <string.h>
23#include <stdarg.h>
24
25#include <asm/bug.h>
26#include "event-parse.h"
27#include "event-utils.h"
28
29/*
30 * The TRACE_SEQ_POISON is to catch the use of using
31 * a trace_seq structure after it was destroyed.
32 */
33#define TRACE_SEQ_POISON ((void *)0xdeadbeef)
34#define TRACE_SEQ_CHECK(s) \
35do { \
36 if (WARN_ONCE((s)->buffer == TRACE_SEQ_POISON, \
37 "Usage of trace_seq after it was destroyed")) \
38 (s)->state = TRACE_SEQ__BUFFER_POISONED; \
39} while (0)
40
41#define TRACE_SEQ_CHECK_RET_N(s, n) \
42do { \
43 TRACE_SEQ_CHECK(s); \
44 if ((s)->state != TRACE_SEQ__GOOD) \
45 return n; \
46} while (0)
47
48#define TRACE_SEQ_CHECK_RET(s) TRACE_SEQ_CHECK_RET_N(s, )
49#define TRACE_SEQ_CHECK_RET0(s) TRACE_SEQ_CHECK_RET_N(s, 0)
50
51/**
52 * trace_seq_init - initialize the trace_seq structure
53 * @s: a pointer to the trace_seq structure to initialize
54 */
55void trace_seq_init(struct trace_seq *s)
56{
57 s->len = 0;
58 s->readpos = 0;
59 s->buffer_size = TRACE_SEQ_BUF_SIZE;
60 s->buffer = malloc(s->buffer_size);
61 if (s->buffer != NULL)
62 s->state = TRACE_SEQ__GOOD;
63 else
64 s->state = TRACE_SEQ__MEM_ALLOC_FAILED;
65}
66
67/**
68 * trace_seq_reset - re-initialize the trace_seq structure
69 * @s: a pointer to the trace_seq structure to reset
70 */
71void trace_seq_reset(struct trace_seq *s)
72{
73 if (!s)
74 return;
75 TRACE_SEQ_CHECK(s);
76 s->len = 0;
77 s->readpos = 0;
78}
79
80/**
81 * trace_seq_destroy - free up memory of a trace_seq
82 * @s: a pointer to the trace_seq to free the buffer
83 *
84 * Only frees the buffer, not the trace_seq struct itself.
85 */
86void trace_seq_destroy(struct trace_seq *s)
87{
88 if (!s)
89 return;
90 TRACE_SEQ_CHECK_RET(s);
91 free(s->buffer);
92 s->buffer = TRACE_SEQ_POISON;
93}
94
95static void expand_buffer(struct trace_seq *s)
96{
97 char *buf;
98
99 buf = realloc(s->buffer, s->buffer_size + TRACE_SEQ_BUF_SIZE);
100 if (WARN_ONCE(!buf, "Can't allocate trace_seq buffer memory")) {
101 s->state = TRACE_SEQ__MEM_ALLOC_FAILED;
102 return;
103 }
104
105 s->buffer = buf;
106 s->buffer_size += TRACE_SEQ_BUF_SIZE;
107}
108
109/**
110 * trace_seq_printf - sequence printing of trace information
111 * @s: trace sequence descriptor
112 * @fmt: printf format string
113 *
114 * It returns 0 if the trace oversizes the buffer's free
115 * space, 1 otherwise.
116 *
117 * The tracer may use either sequence operations or its own
118 * copy to user routines. To simplify formating of a trace
119 * trace_seq_printf is used to store strings into a special
120 * buffer (@s). Then the output may be either used by
121 * the sequencer or pulled into another buffer.
122 */
123int
124trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
125{
126 va_list ap;
127 int len;
128 int ret;
129
130 try_again:
131 TRACE_SEQ_CHECK_RET0(s);
132
133 len = (s->buffer_size - 1) - s->len;
134
135 va_start(ap, fmt);
136 ret = vsnprintf(s->buffer + s->len, len, fmt, ap);
137 va_end(ap);
138
139 if (ret >= len) {
140 expand_buffer(s);
141 goto try_again;
142 }
143
144 s->len += ret;
145
146 return 1;
147}
148
149/**
150 * trace_seq_vprintf - sequence printing of trace information
151 * @s: trace sequence descriptor
152 * @fmt: printf format string
153 *
154 * The tracer may use either sequence operations or its own
155 * copy to user routines. To simplify formating of a trace
156 * trace_seq_printf is used to store strings into a special
157 * buffer (@s). Then the output may be either used by
158 * the sequencer or pulled into another buffer.
159 */
160int
161trace_seq_vprintf(struct trace_seq *s, const char *fmt, va_list args)
162{
163 int len;
164 int ret;
165
166 try_again:
167 TRACE_SEQ_CHECK_RET0(s);
168
169 len = (s->buffer_size - 1) - s->len;
170
171 ret = vsnprintf(s->buffer + s->len, len, fmt, args);
172
173 if (ret >= len) {
174 expand_buffer(s);
175 goto try_again;
176 }
177
178 s->len += ret;
179
180 return len;
181}
182
183/**
184 * trace_seq_puts - trace sequence printing of simple string
185 * @s: trace sequence descriptor
186 * @str: simple string to record
187 *
188 * The tracer may use either the sequence operations or its own
189 * copy to user routines. This function records a simple string
190 * into a special buffer (@s) for later retrieval by a sequencer
191 * or other mechanism.
192 */
193int trace_seq_puts(struct trace_seq *s, const char *str)
194{
195 int len;
196
197 TRACE_SEQ_CHECK_RET0(s);
198
199 len = strlen(str);
200
201 while (len > ((s->buffer_size - 1) - s->len))
202 expand_buffer(s);
203
204 TRACE_SEQ_CHECK_RET0(s);
205
206 memcpy(s->buffer + s->len, str, len);
207 s->len += len;
208
209 return len;
210}
211
212int trace_seq_putc(struct trace_seq *s, unsigned char c)
213{
214 TRACE_SEQ_CHECK_RET0(s);
215
216 while (s->len >= (s->buffer_size - 1))
217 expand_buffer(s);
218
219 TRACE_SEQ_CHECK_RET0(s);
220
221 s->buffer[s->len++] = c;
222
223 return 1;
224}
225
226void trace_seq_terminate(struct trace_seq *s)
227{
228 TRACE_SEQ_CHECK_RET(s);
229
230 /* There's always one character left on the buffer */
231 s->buffer[s->len] = 0;
232}
233
234int trace_seq_do_printf(struct trace_seq *s)
235{
236 TRACE_SEQ_CHECK(s);
237
238 switch (s->state) {
239 case TRACE_SEQ__GOOD:
240 return printf("%.*s", s->len, s->buffer);
241 case TRACE_SEQ__BUFFER_POISONED:
242 puts("Usage of trace_seq after it was destroyed");
243 break;
244 case TRACE_SEQ__MEM_ALLOC_FAILED:
245 puts("Can't allocate trace_seq buffer memory");
246 break;
247 }
248 return -1;
249}
1/*
2 * Copyright (C) 2009 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
3 *
4 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation;
8 * version 2.1 of the License (not later!)
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 Lesser General Public License for more details.
14 *
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
20 */
21#include <stdio.h>
22#include <stdlib.h>
23#include <string.h>
24#include <stdarg.h>
25
26#include "event-parse.h"
27#include "event-utils.h"
28
29/*
30 * The TRACE_SEQ_POISON is to catch the use of using
31 * a trace_seq structure after it was destroyed.
32 */
33#define TRACE_SEQ_POISON ((void *)0xdeadbeef)
34#define TRACE_SEQ_CHECK(s) \
35do { \
36 if ((s)->buffer == TRACE_SEQ_POISON) \
37 die("Usage of trace_seq after it was destroyed"); \
38} while (0)
39
40/**
41 * trace_seq_init - initialize the trace_seq structure
42 * @s: a pointer to the trace_seq structure to initialize
43 */
44void trace_seq_init(struct trace_seq *s)
45{
46 s->len = 0;
47 s->readpos = 0;
48 s->buffer_size = TRACE_SEQ_BUF_SIZE;
49 s->buffer = malloc_or_die(s->buffer_size);
50}
51
52/**
53 * trace_seq_destroy - free up memory of a trace_seq
54 * @s: a pointer to the trace_seq to free the buffer
55 *
56 * Only frees the buffer, not the trace_seq struct itself.
57 */
58void trace_seq_destroy(struct trace_seq *s)
59{
60 if (!s)
61 return;
62 TRACE_SEQ_CHECK(s);
63 free(s->buffer);
64 s->buffer = TRACE_SEQ_POISON;
65}
66
67static void expand_buffer(struct trace_seq *s)
68{
69 s->buffer_size += TRACE_SEQ_BUF_SIZE;
70 s->buffer = realloc(s->buffer, s->buffer_size);
71 if (!s->buffer)
72 die("Can't allocate trace_seq buffer memory");
73}
74
75/**
76 * trace_seq_printf - sequence printing of trace information
77 * @s: trace sequence descriptor
78 * @fmt: printf format string
79 *
80 * It returns 0 if the trace oversizes the buffer's free
81 * space, 1 otherwise.
82 *
83 * The tracer may use either sequence operations or its own
84 * copy to user routines. To simplify formating of a trace
85 * trace_seq_printf is used to store strings into a special
86 * buffer (@s). Then the output may be either used by
87 * the sequencer or pulled into another buffer.
88 */
89int
90trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
91{
92 va_list ap;
93 int len;
94 int ret;
95
96 TRACE_SEQ_CHECK(s);
97
98 try_again:
99 len = (s->buffer_size - 1) - s->len;
100
101 va_start(ap, fmt);
102 ret = vsnprintf(s->buffer + s->len, len, fmt, ap);
103 va_end(ap);
104
105 if (ret >= len) {
106 expand_buffer(s);
107 goto try_again;
108 }
109
110 s->len += ret;
111
112 return 1;
113}
114
115/**
116 * trace_seq_vprintf - sequence printing of trace information
117 * @s: trace sequence descriptor
118 * @fmt: printf format string
119 *
120 * The tracer may use either sequence operations or its own
121 * copy to user routines. To simplify formating of a trace
122 * trace_seq_printf is used to store strings into a special
123 * buffer (@s). Then the output may be either used by
124 * the sequencer or pulled into another buffer.
125 */
126int
127trace_seq_vprintf(struct trace_seq *s, const char *fmt, va_list args)
128{
129 int len;
130 int ret;
131
132 TRACE_SEQ_CHECK(s);
133
134 try_again:
135 len = (s->buffer_size - 1) - s->len;
136
137 ret = vsnprintf(s->buffer + s->len, len, fmt, args);
138
139 if (ret >= len) {
140 expand_buffer(s);
141 goto try_again;
142 }
143
144 s->len += ret;
145
146 return len;
147}
148
149/**
150 * trace_seq_puts - trace sequence printing of simple string
151 * @s: trace sequence descriptor
152 * @str: simple string to record
153 *
154 * The tracer may use either the sequence operations or its own
155 * copy to user routines. This function records a simple string
156 * into a special buffer (@s) for later retrieval by a sequencer
157 * or other mechanism.
158 */
159int trace_seq_puts(struct trace_seq *s, const char *str)
160{
161 int len;
162
163 TRACE_SEQ_CHECK(s);
164
165 len = strlen(str);
166
167 while (len > ((s->buffer_size - 1) - s->len))
168 expand_buffer(s);
169
170 memcpy(s->buffer + s->len, str, len);
171 s->len += len;
172
173 return len;
174}
175
176int trace_seq_putc(struct trace_seq *s, unsigned char c)
177{
178 TRACE_SEQ_CHECK(s);
179
180 while (s->len >= (s->buffer_size - 1))
181 expand_buffer(s);
182
183 s->buffer[s->len++] = c;
184
185 return 1;
186}
187
188void trace_seq_terminate(struct trace_seq *s)
189{
190 TRACE_SEQ_CHECK(s);
191
192 /* There's always one character left on the buffer */
193 s->buffer[s->len] = 0;
194}
195
196int trace_seq_do_printf(struct trace_seq *s)
197{
198 TRACE_SEQ_CHECK(s);
199 return printf("%.*s", s->len, s->buffer);
200}