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6#include "trace-seq.h"
7
8#include <stdio.h>
9#include <stdlib.h>
10#include <string.h>
11#include <stdarg.h>
12
13#include <asm/bug.h>
14#include "event-parse.h"
15#include "event-utils.h"
16
17
18
19
20
21#define TRACE_SEQ_POISON ((void *)0xdeadbeef)
22#define TRACE_SEQ_CHECK(s) \
23do { \
24 if (WARN_ONCE((s)->buffer == TRACE_SEQ_POISON, \
25 "Usage of trace_seq after it was destroyed")) \
26 (s)->state = TRACE_SEQ__BUFFER_POISONED; \
27} while (0)
28
29#define TRACE_SEQ_CHECK_RET_N(s, n) \
30do { \
31 TRACE_SEQ_CHECK(s); \
32 if ((s)->state != TRACE_SEQ__GOOD) \
33 return n; \
34} while (0)
35
36#define TRACE_SEQ_CHECK_RET(s) TRACE_SEQ_CHECK_RET_N(s, )
37#define TRACE_SEQ_CHECK_RET0(s) TRACE_SEQ_CHECK_RET_N(s, 0)
38
39
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41
42
43void trace_seq_init(struct trace_seq *s)
44{
45 s->len = 0;
46 s->readpos = 0;
47 s->buffer_size = TRACE_SEQ_BUF_SIZE;
48 s->buffer = malloc(s->buffer_size);
49 if (s->buffer != NULL)
50 s->state = TRACE_SEQ__GOOD;
51 else
52 s->state = TRACE_SEQ__MEM_ALLOC_FAILED;
53}
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58
59void trace_seq_reset(struct trace_seq *s)
60{
61 if (!s)
62 return;
63 TRACE_SEQ_CHECK(s);
64 s->len = 0;
65 s->readpos = 0;
66}
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72
73
74void trace_seq_destroy(struct trace_seq *s)
75{
76 if (!s)
77 return;
78 TRACE_SEQ_CHECK_RET(s);
79 free(s->buffer);
80 s->buffer = TRACE_SEQ_POISON;
81}
82
83static void expand_buffer(struct trace_seq *s)
84{
85 char *buf;
86
87 buf = realloc(s->buffer, s->buffer_size + TRACE_SEQ_BUF_SIZE);
88 if (WARN_ONCE(!buf, "Can't allocate trace_seq buffer memory")) {
89 s->state = TRACE_SEQ__MEM_ALLOC_FAILED;
90 return;
91 }
92
93 s->buffer = buf;
94 s->buffer_size += TRACE_SEQ_BUF_SIZE;
95}
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112int
113trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
114{
115 va_list ap;
116 int len;
117 int ret;
118
119 try_again:
120 TRACE_SEQ_CHECK_RET0(s);
121
122 len = (s->buffer_size - 1) - s->len;
123
124 va_start(ap, fmt);
125 ret = vsnprintf(s->buffer + s->len, len, fmt, ap);
126 va_end(ap);
127
128 if (ret >= len) {
129 expand_buffer(s);
130 goto try_again;
131 }
132
133 if (ret > 0)
134 s->len += ret;
135
136 return ret;
137}
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153
154int
155trace_seq_vprintf(struct trace_seq *s, const char *fmt, va_list args)
156{
157 int len;
158 int ret;
159
160 try_again:
161 TRACE_SEQ_CHECK_RET0(s);
162
163 len = (s->buffer_size - 1) - s->len;
164
165 ret = vsnprintf(s->buffer + s->len, len, fmt, args);
166
167 if (ret >= len) {
168 expand_buffer(s);
169 goto try_again;
170 }
171
172 if (ret > 0)
173 s->len += ret;
174
175 return ret;
176}
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186
187
188int trace_seq_puts(struct trace_seq *s, const char *str)
189{
190 int len;
191
192 TRACE_SEQ_CHECK_RET0(s);
193
194 len = strlen(str);
195
196 while (len > ((s->buffer_size - 1) - s->len))
197 expand_buffer(s);
198
199 TRACE_SEQ_CHECK_RET0(s);
200
201 memcpy(s->buffer + s->len, str, len);
202 s->len += len;
203
204 return len;
205}
206
207int trace_seq_putc(struct trace_seq *s, unsigned char c)
208{
209 TRACE_SEQ_CHECK_RET0(s);
210
211 while (s->len >= (s->buffer_size - 1))
212 expand_buffer(s);
213
214 TRACE_SEQ_CHECK_RET0(s);
215
216 s->buffer[s->len++] = c;
217
218 return 1;
219}
220
221void trace_seq_terminate(struct trace_seq *s)
222{
223 TRACE_SEQ_CHECK_RET(s);
224
225
226 s->buffer[s->len] = 0;
227}
228
229int trace_seq_do_fprintf(struct trace_seq *s, FILE *fp)
230{
231 TRACE_SEQ_CHECK(s);
232
233 switch (s->state) {
234 case TRACE_SEQ__GOOD:
235 return fprintf(fp, "%.*s", s->len, s->buffer);
236 case TRACE_SEQ__BUFFER_POISONED:
237 fprintf(fp, "%s\n", "Usage of trace_seq after it was destroyed");
238 break;
239 case TRACE_SEQ__MEM_ALLOC_FAILED:
240 fprintf(fp, "%s\n", "Can't allocate trace_seq buffer memory");
241 break;
242 }
243 return -1;
244}
245
246int trace_seq_do_printf(struct trace_seq *s)
247{
248 return trace_seq_do_fprintf(s, stdout);
249}
250