1 /*
2 * Copyright (c) Huawei Technologies Co., Ltd. 2021. All rights reserved.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15 #include "ftrace_field_parser.h"
16 #include "logging.h"
17 #include "printk_formats_parser.h"
18 #include "securec.h"
19
20 #include <cinttypes>
21 #include <cstring>
22 #include <fcntl.h>
23 #include <memory>
24 #include <unistd.h>
25
26 FTRACE_NS_BEGIN
27 namespace {
28 constexpr uint32_t DATALOC_OFFSET_MASK = 0xffff;
29 constexpr uint32_t DATALOC_LENGTH_MASK = 0xffff;
30 constexpr uint32_t DATALOC_LENGTH_SHIFT = 16;
31
ReadString(const uint8_t start[],const uint8_t end[],int size)32 std::string ReadString(const uint8_t start[], const uint8_t end[], int size)
33 {
34 std::string str;
35
36 if (end - start < static_cast<ptrdiff_t>(size)) {
37 return str;
38 }
39
40 const uint8_t* cursor = start;
41 const uint8_t* sectionEnd = start + size;
42 while (*cursor && cursor < sectionEnd) {
43 cursor++;
44 }
45
46 str.assign(start, cursor);
47 return str;
48 }
49 } // namespace
50
ReadData(const uint8_t start[],const uint8_t end[],void * out,size_t size)51 bool FtraceFieldParser::ReadData(const uint8_t start[], const uint8_t end[], void* out, size_t size)
52 {
53 ptrdiff_t memSize = end - start;
54 if (memSize < static_cast<ptrdiff_t>(size)) {
55 return false;
56 }
57
58 CHECK_TRUE(memcpy_s(out, size, start, size) == EOK, false, "copy %zu byte to memory FAILED!", size);
59 return true;
60 }
61
ParseStrField(const FieldFormat & format,uint8_t data[],size_t size)62 std::string FtraceFieldParser::ParseStrField(const FieldFormat& format, uint8_t data[], size_t size)
63 {
64 std::string retval;
65 if ((format.offset + format.size) > size) {
66 return retval;
67 }
68
69 uint8_t* start = data + format.offset;
70 uint8_t* end = data + size;
71 size_t strSize = 0;
72 uint64_t strPtr = 0;
73 uint32_t dataLoc = 0;
74 uint32_t dataOffset = 0;
75 uint32_t dataLength = 0;
76
77 switch (format.filedType) {
78 case FIELD_TYPE_FIXEDCSTRING:
79 retval = ReadString(start, end, format.size);
80 break;
81 case FIELD_TYPE_CSTRING:
82 strSize = format.size;
83 if (strSize == 0) {
84 strSize = end - start;
85 retval = ReadString(start, end, strSize);
86 } else {
87 retval = ReadString(start, end, strSize);
88 }
89 break;
90 case FIELD_TYPE_STRINGPTR:
91 strSize = std::min(static_cast<size_t>(format.size), sizeof(strPtr));
92 CHECK_TRUE(memcpy_s(&strPtr, sizeof(strPtr), start, strSize) == EOK, "",
93 "parse STRINGPTR at %" PRIx64 " with %zu size FAILED!", strPtr, strSize);
94 retval = PrintkFormatsParser::GetInstance().GetSymbol(strPtr);
95 break;
96 case FIELD_TYPE_DATALOC:
97 dataLoc = 0;
98 ReadData(start, end, &dataLoc, sizeof(dataLoc));
99 dataOffset = dataLoc & DATALOC_OFFSET_MASK;
100 dataLength = (dataLoc >> DATALOC_LENGTH_SHIFT) & DATALOC_LENGTH_MASK;
101 if (dataOffset > 0 && data + dataOffset + dataLength <= end) {
102 retval = ReadString(data + dataOffset, end, dataLength);
103 }
104 break;
105 default:
106 break;
107 }
108 return retval;
109 }
110 FTRACE_NS_END
111