Commit | Line | Data |
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5024c2ac JR |
1 | /* |
2 | * Copyright 2020 EfficiOS, Inc. | |
3 | * | |
4 | * SPDX-License-Identifier: GPL-2.0-only | |
5 | * | |
6 | */ | |
7 | ||
8 | #include "bytecode.h" | |
9 | ||
10 | #include <errno.h> | |
11 | ||
12 | #include "common/align.h" | |
13 | ||
14 | #define INIT_ALLOC_SIZE 4 | |
15 | ||
16 | static inline int get_count_order(unsigned int count) | |
17 | { | |
18 | int order; | |
19 | ||
20 | order = lttng_fls(count) - 1; | |
21 | if (count & (count - 1)) | |
22 | order++; | |
23 | return order; | |
24 | } | |
25 | ||
26 | LTTNG_HIDDEN | |
27 | int bytecode_init(struct lttng_bytecode_alloc **fb) | |
28 | { | |
29 | uint32_t alloc_len; | |
30 | ||
31 | alloc_len = sizeof(struct lttng_bytecode_alloc) + INIT_ALLOC_SIZE; | |
32 | *fb = calloc(alloc_len, 1); | |
33 | if (!*fb) { | |
34 | return -ENOMEM; | |
35 | } else { | |
36 | (*fb)->alloc_len = alloc_len; | |
37 | return 0; | |
38 | } | |
39 | } | |
40 | ||
41 | LTTNG_HIDDEN | |
42 | int32_t bytecode_reserve(struct lttng_bytecode_alloc **fb, uint32_t align, uint32_t len) | |
43 | { | |
44 | int32_t ret; | |
45 | uint32_t padding = offset_align((*fb)->b.len, align); | |
46 | uint32_t new_len = (*fb)->b.len + padding + len; | |
47 | uint32_t new_alloc_len = sizeof(struct lttng_bytecode_alloc) + new_len; | |
48 | uint32_t old_alloc_len = (*fb)->alloc_len; | |
49 | ||
50 | if (new_len > LTTNG_FILTER_MAX_LEN) | |
51 | return -EINVAL; | |
52 | ||
53 | if (new_alloc_len > old_alloc_len) { | |
54 | struct lttng_bytecode_alloc *newptr; | |
55 | ||
56 | new_alloc_len = | |
57 | max_t(uint32_t, 1U << get_count_order(new_alloc_len), old_alloc_len << 1); | |
58 | newptr = realloc(*fb, new_alloc_len); | |
59 | if (!newptr) | |
60 | return -ENOMEM; | |
61 | *fb = newptr; | |
62 | /* We zero directly the memory from start of allocation. */ | |
63 | memset(&((char *) *fb)[old_alloc_len], 0, new_alloc_len - old_alloc_len); | |
64 | (*fb)->alloc_len = new_alloc_len; | |
65 | } | |
66 | (*fb)->b.len += padding; | |
67 | ret = (*fb)->b.len; | |
68 | (*fb)->b.len += len; | |
69 | return ret; | |
70 | } | |
71 | ||
72 | LTTNG_HIDDEN | |
73 | int bytecode_push(struct lttng_bytecode_alloc **fb, const void *data, | |
74 | uint32_t align, uint32_t len) | |
75 | { | |
76 | int32_t offset; | |
77 | ||
78 | offset = bytecode_reserve(fb, align, len); | |
79 | if (offset < 0) | |
80 | return offset; | |
81 | memcpy(&(*fb)->b.data[offset], data, len); | |
82 | return 0; | |
83 | } | |
84 | ||
85 | LTTNG_HIDDEN | |
86 | int bytecode_push_logical(struct lttng_bytecode_alloc **fb, | |
87 | struct logical_op *data, | |
88 | uint32_t align, uint32_t len, | |
89 | uint16_t *skip_offset) | |
90 | { | |
91 | int32_t offset; | |
92 | ||
93 | offset = bytecode_reserve(fb, align, len); | |
94 | if (offset < 0) | |
95 | return offset; | |
96 | memcpy(&(*fb)->b.data[offset], data, len); | |
97 | *skip_offset = | |
98 | (void *) &((struct logical_op *) &(*fb)->b.data[offset])->skip_offset | |
99 | - (void *) &(*fb)->b.data[0]; | |
100 | return 0; | |
101 | } | |
102 | ||
103 | LTTNG_HIDDEN | |
104 | int bytecode_push_get_payload_root(struct lttng_bytecode_alloc **bytecode) | |
105 | { | |
106 | struct load_op *insn; | |
107 | uint32_t insn_len = sizeof(struct load_op); | |
108 | int ret; | |
109 | ||
110 | insn = calloc(insn_len, 1); | |
111 | if (!insn) | |
112 | return -ENOMEM; | |
113 | ||
114 | insn->op = BYTECODE_OP_GET_PAYLOAD_ROOT; | |
115 | ret = bytecode_push(bytecode, insn, 1, insn_len); | |
116 | free(insn); | |
117 | ||
118 | return ret; | |
119 | } | |
120 | ||
121 | LTTNG_HIDDEN | |
122 | int bytecode_push_get_context_root(struct lttng_bytecode_alloc **bytecode) | |
123 | { | |
124 | struct load_op *insn; | |
125 | uint32_t insn_len = sizeof(struct load_op); | |
126 | int ret; | |
127 | ||
128 | insn = calloc(insn_len, 1); | |
129 | if (!insn) | |
130 | return -ENOMEM; | |
131 | ||
132 | insn->op = BYTECODE_OP_GET_CONTEXT_ROOT; | |
133 | ret = bytecode_push(bytecode, insn, 1, insn_len); | |
134 | free(insn); | |
135 | ||
136 | return ret; | |
137 | } | |
138 | ||
139 | LTTNG_HIDDEN | |
140 | int bytecode_push_get_app_context_root(struct lttng_bytecode_alloc **bytecode) | |
141 | { | |
142 | struct load_op *insn; | |
143 | uint32_t insn_len = sizeof(struct load_op); | |
144 | int ret; | |
145 | ||
146 | insn = calloc(insn_len, 1); | |
147 | if (!insn) | |
148 | return -ENOMEM; | |
149 | ||
150 | insn->op = BYTECODE_OP_GET_APP_CONTEXT_ROOT; | |
151 | ret = bytecode_push(bytecode, insn, 1, insn_len); | |
152 | free(insn); | |
153 | ||
154 | return ret; | |
155 | } | |
156 | ||
157 | LTTNG_HIDDEN | |
158 | int bytecode_push_get_index_u64(struct lttng_bytecode_alloc **bytecode, | |
159 | uint64_t index) | |
160 | { | |
161 | struct load_op *insn; | |
162 | uint32_t insn_len = sizeof(struct load_op) | |
163 | + sizeof(struct get_index_u64); | |
164 | struct get_index_u64 index_op_data; | |
165 | int ret; | |
166 | ||
167 | insn = calloc(insn_len, 1); | |
168 | if (!insn) | |
169 | return -ENOMEM; | |
170 | ||
171 | insn->op = BYTECODE_OP_GET_INDEX_U64; | |
172 | index_op_data.index = index; | |
173 | memcpy(insn->data, &index_op_data, sizeof(index)); | |
174 | ret = bytecode_push(bytecode, insn, 1, insn_len); | |
175 | ||
176 | free(insn); | |
177 | ||
178 | return ret; | |
179 | } | |
180 | ||
181 | LTTNG_HIDDEN | |
182 | int bytecode_push_get_symbol(struct lttng_bytecode_alloc **bytecode, | |
183 | struct lttng_bytecode_alloc **bytecode_reloc, | |
184 | const char *symbol) | |
185 | { | |
186 | struct load_op *insn; | |
187 | uint32_t insn_len = sizeof(struct load_op) | |
188 | + sizeof(struct get_symbol); | |
189 | struct get_symbol symbol_offset; | |
190 | uint32_t reloc_offset_u32; | |
191 | uint16_t reloc_offset; | |
192 | uint32_t bytecode_reloc_offset_u32; | |
193 | int ret; | |
194 | ||
195 | insn = calloc(insn_len, 1); | |
196 | if (!insn) { | |
197 | ret = -ENOMEM; | |
198 | goto end; | |
199 | } | |
200 | ||
201 | insn->op = BYTECODE_OP_GET_SYMBOL; | |
202 | ||
203 | /* | |
204 | * Get offset in the reloc portion at which the symbol name | |
205 | * will end up at (GET_SYMBOL's operand points there). | |
206 | */ | |
207 | bytecode_reloc_offset_u32 = | |
208 | bytecode_get_len(&(*bytecode_reloc)->b) | |
209 | + sizeof(reloc_offset); | |
210 | symbol_offset.offset = (uint16_t) bytecode_reloc_offset_u32; | |
211 | memcpy(insn->data, &symbol_offset, sizeof(symbol_offset)); | |
212 | ||
213 | /* | |
214 | * Get offset in the bytecode where the opcode will end up at, | |
215 | * the reloc offset points to it. | |
216 | */ | |
217 | reloc_offset_u32 = bytecode_get_len(&(*bytecode)->b); | |
218 | if (reloc_offset_u32 > LTTNG_FILTER_MAX_LEN - 1) { | |
219 | ret = -EINVAL; | |
220 | goto end; | |
221 | } | |
222 | reloc_offset = (uint16_t) reloc_offset_u32; | |
223 | ||
224 | /* Append op in bytecode. */ | |
225 | ret = bytecode_push(bytecode, insn, 1, insn_len); | |
226 | if (ret) { | |
227 | goto end; | |
228 | } | |
229 | ||
230 | /* Append reloc offset. */ | |
231 | ret = bytecode_push(bytecode_reloc, &reloc_offset, | |
232 | 1, sizeof(reloc_offset)); | |
233 | if (ret) { | |
234 | goto end; | |
235 | } | |
236 | ||
237 | /* Append symbol name. */ | |
238 | ret = bytecode_push(bytecode_reloc, symbol, 1, strlen(symbol) + 1); | |
239 | ||
240 | end: | |
241 | free(insn); | |
242 | return ret; | |
243 | } | |
244 | ||
245 | /* | |
246 | * Allocate an lttng_bytecode object and copy the given original bytecode. | |
247 | * | |
248 | * Return allocated bytecode or NULL on error. | |
249 | */ | |
250 | struct lttng_bytecode *bytecode_copy( | |
251 | const struct lttng_bytecode *orig_f) | |
252 | { | |
253 | struct lttng_bytecode *bytecode = NULL; | |
254 | ||
255 | bytecode = zmalloc(sizeof(*bytecode) + orig_f->len); | |
256 | if (!bytecode) { | |
257 | goto error; | |
258 | } | |
259 | ||
260 | memcpy(bytecode, orig_f, sizeof(*bytecode) + orig_f->len); | |
261 | ||
262 | error: | |
263 | return bytecode; | |
264 | } |