1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
|
/* SPDX-License-Identifier: GPL-2.0 */
/*
* Traceprobe fetch helper inlines
*/
static nokprobe_inline void
fetch_store_raw(unsigned long val, struct fetch_insn *code, void *buf)
{
switch (code->size) {
case 1:
*(u8 *)buf = (u8)val;
break;
case 2:
*(u16 *)buf = (u16)val;
break;
case 4:
*(u32 *)buf = (u32)val;
break;
case 8:
//TBD: 32bit signed
*(u64 *)buf = (u64)val;
break;
default:
*(unsigned long *)buf = val;
}
}
static nokprobe_inline void
fetch_apply_bitfield(struct fetch_insn *code, void *buf)
{
switch (code->basesize) {
case 1:
*(u8 *)buf <<= code->lshift;
*(u8 *)buf >>= code->rshift;
break;
case 2:
*(u16 *)buf <<= code->lshift;
*(u16 *)buf >>= code->rshift;
break;
case 4:
*(u32 *)buf <<= code->lshift;
*(u32 *)buf >>= code->rshift;
break;
case 8:
*(u64 *)buf <<= code->lshift;
*(u64 *)buf >>= code->rshift;
break;
}
}
/*
* These functions must be defined for each callsite.
* Return consumed dynamic data size (>= 0), or error (< 0).
* If dest is NULL, don't store result and return required dynamic data size.
*/
static int
process_fetch_insn(struct fetch_insn *code, void *rec, void *edata,
void *dest, void *base);
static nokprobe_inline int fetch_store_strlen(unsigned long addr);
static nokprobe_inline int
fetch_store_string(unsigned long addr, void *dest, void *base);
static nokprobe_inline int fetch_store_strlen_user(unsigned long addr);
static nokprobe_inline int
fetch_store_string_user(unsigned long addr, void *dest, void *base);
static nokprobe_inline int
probe_mem_read(void *dest, void *src, size_t size);
static nokprobe_inline int
probe_mem_read_user(void *dest, void *src, size_t size);
static nokprobe_inline int
fetch_store_symstrlen(unsigned long addr)
{
char namebuf[KSYM_SYMBOL_LEN];
int ret;
ret = sprint_symbol(namebuf, addr);
if (ret < 0)
return 0;
return ret + 1;
}
/*
* Fetch a null-terminated symbol string + offset. Caller MUST set *(u32 *)buf
* with max length and relative data location.
*/
static nokprobe_inline int
fetch_store_symstring(unsigned long addr, void *dest, void *base)
{
int maxlen = get_loc_len(*(u32 *)dest);
void *__dest;
if (unlikely(!maxlen))
return -ENOMEM;
__dest = get_loc_data(dest, base);
return sprint_symbol(__dest, addr);
}
/* common part of process_fetch_insn*/
static nokprobe_inline int
process_common_fetch_insn(struct fetch_insn *code, unsigned long *val)
{
switch (code->op) {
case FETCH_OP_IMM:
*val = code->immediate;
break;
case FETCH_OP_COMM:
*val = (unsigned long)current->comm;
break;
case FETCH_OP_DATA:
*val = (unsigned long)code->data;
break;
default:
return -EILSEQ;
}
return 0;
}
/* From the 2nd stage, routine is same */
static nokprobe_inline int
process_fetch_insn_bottom(struct fetch_insn *code, unsigned long val,
void *dest, void *base)
{
struct fetch_insn *s3 = NULL;
int total = 0, ret = 0, i = 0;
u32 loc = 0;
unsigned long lval = val;
stage2:
/* 2nd stage: dereference memory if needed */
do {
if (code->op == FETCH_OP_DEREF) {
lval = val;
ret = probe_mem_read(&val, (void *)val + code->offset,
sizeof(val));
} else if (code->op == FETCH_OP_UDEREF) {
lval = val;
ret = probe_mem_read_user(&val,
(void *)val + code->offset, sizeof(val));
} else
break;
if (ret)
return ret;
code++;
} while (1);
s3 = code;
stage3:
/* 3rd stage: store value to buffer */
if (unlikely(!dest)) {
switch (code->op) {
case FETCH_OP_ST_STRING:
ret = fetch_store_strlen(val + code->offset);
code++;
goto array;
case FETCH_OP_ST_USTRING:
ret = fetch_store_strlen_user(val + code->offset);
code++;
goto array;
case FETCH_OP_ST_SYMSTR:
ret = fetch_store_symstrlen(val + code->offset);
code++;
goto array;
default:
return -EILSEQ;
}
}
switch (code->op) {
case FETCH_OP_ST_RAW:
fetch_store_raw(val, code, dest);
break;
case FETCH_OP_ST_MEM:
probe_mem_read(dest, (void *)val + code->offset, code->size);
break;
case FETCH_OP_ST_UMEM:
probe_mem_read_user(dest, (void *)val + code->offset, code->size);
break;
case FETCH_OP_ST_STRING:
loc = *(u32 *)dest;
ret = fetch_store_string(val + code->offset, dest, base);
break;
case FETCH_OP_ST_USTRING:
loc = *(u32 *)dest;
ret = fetch_store_string_user(val + code->offset, dest, base);
break;
case FETCH_OP_ST_SYMSTR:
loc = *(u32 *)dest;
ret = fetch_store_symstring(val + code->offset, dest, base);
break;
default:
return -EILSEQ;
}
code++;
/* 4th stage: modify stored value if needed */
if (code->op == FETCH_OP_MOD_BF) {
fetch_apply_bitfield(code, dest);
code++;
}
array:
/* the last stage: Loop on array */
if (code->op == FETCH_OP_LP_ARRAY) {
if (ret < 0)
ret = 0;
total += ret;
if (++i < code->param) {
code = s3;
if (s3->op != FETCH_OP_ST_STRING &&
s3->op != FETCH_OP_ST_USTRING) {
dest += s3->size;
val += s3->size;
goto stage3;
}
code--;
val = lval + sizeof(char *);
if (dest) {
dest += sizeof(u32);
*(u32 *)dest = update_data_loc(loc, ret);
}
goto stage2;
}
code++;
ret = total;
}
return code->op == FETCH_OP_END ? ret : -EILSEQ;
}
/* Sum up total data length for dynamic arrays (strings) */
static nokprobe_inline int
__get_data_size(struct trace_probe *tp, struct pt_regs *regs, void *edata)
{
struct probe_arg *arg;
int i, len, ret = 0;
for (i = 0; i < tp->nr_args; i++) {
arg = tp->args + i;
if (unlikely(arg->dynamic)) {
len = process_fetch_insn(arg->code, regs, edata, NULL, NULL);
if (len > 0)
ret += len;
}
}
return ret;
}
/* Store the value of each argument */
static nokprobe_inline void
store_trace_args(void *data, struct trace_probe *tp, void *rec, void *edata,
int header_size, int maxlen)
{
struct probe_arg *arg;
void *base = data - header_size;
void *dyndata = data + tp->size;
u32 *dl; /* Data location */
int ret, i;
for (i = 0; i < tp->nr_args; i++) {
arg = tp->args + i;
dl = data + arg->offset;
/* Point the dynamic data area if needed */
if (unlikely(arg->dynamic))
*dl = make_data_loc(maxlen, dyndata - base);
ret = process_fetch_insn(arg->code, rec, edata, dl, base);
if (arg->dynamic && likely(ret > 0)) {
dyndata += ret;
maxlen -= ret;
}
}
}
|
