| 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 | } |
| 102 | |
| 103 | /* |
| 104 | * Allocate an lttng_bytecode object and copy the given original bytecode. |
| 105 | * |
| 106 | * Return allocated bytecode or NULL on error. |
| 107 | */ |
| 108 | LTTNG_HIDDEN |
| 109 | struct lttng_filter_bytecode *lttng_filter_bytecode_copy( |
| 110 | const struct lttng_filter_bytecode *orig_f) |
| 111 | { |
| 112 | struct lttng_filter_bytecode *bytecode = NULL; |
| 113 | |
| 114 | bytecode = zmalloc(sizeof(*bytecode) + orig_f->len); |
| 115 | if (!bytecode) { |
| 116 | goto error; |
| 117 | } |
| 118 | |
| 119 | memcpy(bytecode, orig_f, sizeof(*bytecode) + orig_f->len); |
| 120 | |
| 121 | error: |
| 122 | return bytecode; |
| 123 | } |