+/*
+ * Copyright 2020 EfficiOS, Inc.
+ *
+ * SPDX-License-Identifier: GPL-2.0-only
+ *
+ */
+
+#include "bytecode.h"
+
+#include <errno.h>
+#include <algorithm>
+
+#include "common/align.h"
+
+#define INIT_ALLOC_SIZE 4
+
+static inline
+int get_count_order(unsigned int count)
+{
+ int order;
+
+ order = lttng_fls(count) - 1;
+ if (count & (count - 1))
+ order++;
+ return order;
+}
+
+int bytecode_init(struct lttng_bytecode_alloc **fb)
+{
+ uint32_t alloc_len;
+
+ alloc_len = sizeof(struct lttng_bytecode_alloc) + INIT_ALLOC_SIZE;
+ *fb = (lttng_bytecode_alloc *) calloc(alloc_len, 1);
+ if (!*fb) {
+ return -ENOMEM;
+ } else {
+ (*fb)->alloc_len = alloc_len;
+ return 0;
+ }
+}
+
+static
+int32_t bytecode_reserve(struct lttng_bytecode_alloc **fb, uint32_t align, uint32_t len)
+{
+ int32_t ret;
+ uint32_t padding = lttng_offset_align((*fb)->b.len, align);
+ uint32_t new_len = (*fb)->b.len + padding + len;
+ uint32_t new_alloc_len = sizeof(struct lttng_bytecode_alloc) + new_len;
+ uint32_t old_alloc_len = (*fb)->alloc_len;
+
+ if (new_len > LTTNG_FILTER_MAX_LEN)
+ return -EINVAL;
+
+ if (new_alloc_len > old_alloc_len) {
+ struct lttng_bytecode_alloc *newptr;
+
+ new_alloc_len =
+ std::max(1U << get_count_order(new_alloc_len), old_alloc_len << 1);
+ newptr = (lttng_bytecode_alloc *) realloc(*fb, new_alloc_len);
+ if (!newptr)
+ return -ENOMEM;
+ *fb = newptr;
+ /* We zero directly the memory from start of allocation. */
+ memset(&((char *) *fb)[old_alloc_len], 0, new_alloc_len - old_alloc_len);
+ (*fb)->alloc_len = new_alloc_len;
+ }
+ (*fb)->b.len += padding;
+ ret = (*fb)->b.len;
+ (*fb)->b.len += len;
+ return ret;
+}
+
+int bytecode_push(struct lttng_bytecode_alloc **fb, const void *data,
+ uint32_t align, uint32_t len)
+{
+ int32_t offset;
+
+ offset = bytecode_reserve(fb, align, len);
+ if (offset < 0)
+ return offset;
+ memcpy(&(*fb)->b.data[offset], data, len);
+ return 0;
+}
+
+int bytecode_push_logical(struct lttng_bytecode_alloc **fb,
+ struct logical_op *data,
+ uint32_t align, uint32_t len,
+ uint16_t *skip_offset)
+{
+ int32_t offset;
+
+ offset = bytecode_reserve(fb, align, len);
+ if (offset < 0)
+ return offset;
+ memcpy(&(*fb)->b.data[offset], data, len);
+ *skip_offset =
+ (char *) &((struct logical_op *) &(*fb)->b.data[offset])->skip_offset
+ - (char *) &(*fb)->b.data[0];
+ return 0;
+}
+
+int bytecode_push_get_payload_root(struct lttng_bytecode_alloc **bytecode)
+{
+ int ret;
+ struct load_op *insn;
+ const uint32_t insn_len = sizeof(struct load_op);
+
+ insn = (load_op *) calloc(insn_len, 1);
+ if (!insn) {
+ ret = -ENOMEM;
+ goto end;
+ }
+
+ insn->op = BYTECODE_OP_GET_PAYLOAD_ROOT;
+ ret = bytecode_push(bytecode, insn, 1, insn_len);
+ free(insn);
+end:
+ return ret;
+}
+
+int bytecode_push_get_context_root(struct lttng_bytecode_alloc **bytecode)
+{
+ int ret;
+ struct load_op *insn;
+ const uint32_t insn_len = sizeof(struct load_op);
+
+ insn = (load_op *) calloc(insn_len, 1);
+ if (!insn) {
+ ret = -ENOMEM;
+ goto end;
+ }
+
+ insn->op = BYTECODE_OP_GET_CONTEXT_ROOT;
+ ret = bytecode_push(bytecode, insn, 1, insn_len);
+ free(insn);
+end:
+ return ret;
+}
+
+int bytecode_push_get_app_context_root(struct lttng_bytecode_alloc **bytecode)
+{
+ int ret;
+ struct load_op *insn;
+ const uint32_t insn_len = sizeof(struct load_op);
+
+ insn = (load_op *) calloc(insn_len, 1);
+ if (!insn) {
+ ret = -ENOMEM;
+ goto end;
+ }
+
+ insn->op = BYTECODE_OP_GET_APP_CONTEXT_ROOT;
+ ret = bytecode_push(bytecode, insn, 1, insn_len);
+ free(insn);
+end:
+ return ret;
+}
+
+int bytecode_push_get_index_u64(struct lttng_bytecode_alloc **bytecode,
+ uint64_t index)
+{
+ int ret;
+ struct load_op *insn;
+ struct get_index_u64 index_op_data;
+ const uint32_t insn_len =
+ sizeof(struct load_op) + sizeof(struct get_index_u64);
+
+ insn = (load_op *) calloc(insn_len, 1);
+ if (!insn) {
+ ret = -ENOMEM;
+ goto end;
+ }
+
+ insn->op = BYTECODE_OP_GET_INDEX_U64;
+ index_op_data.index = index;
+ memcpy(insn->data, &index_op_data, sizeof(index));
+ ret = bytecode_push(bytecode, insn, 1, insn_len);
+
+ free(insn);
+end:
+ return ret;
+}
+
+int bytecode_push_get_symbol(struct lttng_bytecode_alloc **bytecode,
+ struct lttng_bytecode_alloc **bytecode_reloc,
+ const char *symbol)
+{
+ int ret;
+ struct load_op *insn;
+ struct get_symbol symbol_offset;
+ uint32_t reloc_offset_u32;
+ uint16_t reloc_offset;
+ uint32_t bytecode_reloc_offset_u32;
+ const uint32_t insn_len =
+ sizeof(struct load_op) + sizeof(struct get_symbol);
+
+ insn = (load_op *) calloc(insn_len, 1);
+ if (!insn) {
+ ret = -ENOMEM;
+ goto end;
+ }
+
+ insn->op = BYTECODE_OP_GET_SYMBOL;
+
+ /*
+ * Get offset in the reloc portion at which the symbol name
+ * will end up at (GET_SYMBOL's operand points there).
+ */
+ bytecode_reloc_offset_u32 = bytecode_get_len(&(*bytecode_reloc)->b) +
+ sizeof(reloc_offset);
+ symbol_offset.offset = (uint16_t) bytecode_reloc_offset_u32;
+ memcpy(insn->data, &symbol_offset, sizeof(symbol_offset));
+
+ /*
+ * Get offset in the bytecode where the opcode will end up at,
+ * the reloc offset points to it.
+ */
+ reloc_offset_u32 = bytecode_get_len(&(*bytecode)->b);
+ if (reloc_offset_u32 > LTTNG_FILTER_MAX_LEN - 1) {
+ ret = -EINVAL;
+ goto end;
+ }
+ reloc_offset = (uint16_t) reloc_offset_u32;
+
+ /* Append op in bytecode. */
+ ret = bytecode_push(bytecode, insn, 1, insn_len);
+ if (ret) {
+ goto end;
+ }
+
+ /* Append reloc offset. */
+ ret = bytecode_push(bytecode_reloc, &reloc_offset,
+ 1, sizeof(reloc_offset));
+ if (ret) {
+ goto end;
+ }
+
+ /* Append symbol name. */
+ ret = bytecode_push(bytecode_reloc, symbol, 1, strlen(symbol) + 1);
+
+end:
+ free(insn);
+ return ret;
+}
+
+/*
+ * Allocate an lttng_bytecode object and copy the given original bytecode.
+ *
+ * Return allocated bytecode or NULL on error.
+ */
+struct lttng_bytecode *lttng_bytecode_copy(
+ const struct lttng_bytecode *orig_f)
+{
+ struct lttng_bytecode *bytecode = NULL;
+
+ bytecode = (lttng_bytecode *) zmalloc(sizeof(*bytecode) + orig_f->len);
+ if (!bytecode) {
+ goto error;
+ }
+
+ memcpy(bytecode, orig_f, sizeof(*bytecode) + orig_f->len);
+
+error:
+ return bytecode;
+}
projects / lttng-tools.git / commitdiff
