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0ae3cfc6 SM |
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_filter_bytecode_alloc **fb) | |
28 | { | |
29 | uint32_t alloc_len; | |
30 | ||
31 | alloc_len = sizeof(struct lttng_filter_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_filter_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_filter_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_filter_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_filter_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_filter_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 | } |