1 | // Copyright (c) 2013, Google Inc. |
2 | // All rights reserved. |
3 | // |
4 | // Redistribution and use in source and binary forms, with or without |
5 | // modification, are permitted provided that the following conditions are |
6 | // met: |
7 | // |
8 | // * Redistributions of source code must retain the above copyright |
9 | // notice, this list of conditions and the following disclaimer. |
10 | // * Redistributions in binary form must reproduce the above |
11 | // copyright notice, this list of conditions and the following disclaimer |
12 | // in the documentation and/or other materials provided with the |
13 | // distribution. |
14 | // * Neither the name of Google Inc. nor the names of its |
15 | // contributors may be used to endorse or promote products derived from |
16 | // this software without specific prior written permission. |
17 | // |
18 | // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
19 | // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
20 | // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
21 | // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
22 | // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
23 | // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
24 | // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
25 | // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
26 | // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
27 | // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
28 | // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
29 | |
30 | #ifndef CLIENT_LINUX_MINIDUMP_WRITER_PROC_CPUINFO_READER_H_ |
31 | #define CLIENT_LINUX_MINIDUMP_WRITER_PROC_CPUINFO_READER_H_ |
32 | |
33 | #include <stdint.h> |
34 | #include <assert.h> |
35 | #include <string.h> |
36 | |
37 | #include "client/linux/minidump_writer/line_reader.h" |
38 | #include "common/linux/linux_libc_support.h" |
39 | #include "third_party/lss/linux_syscall_support.h" |
40 | |
41 | namespace google_breakpad { |
42 | |
43 | // A class for reading /proc/cpuinfo without using fopen/fgets or other |
44 | // functions which may allocate memory. |
45 | class ProcCpuInfoReader { |
46 | public: |
47 | ProcCpuInfoReader(int fd) |
48 | : line_reader_(fd), pop_count_(-1) { |
49 | } |
50 | |
51 | // Return the next field name, or NULL in case of EOF. |
52 | // field: (output) Pointer to zero-terminated field name. |
53 | // Returns true on success, or false on EOF or error (line too long). |
54 | bool GetNextField(const char** field) { |
55 | for (;;) { |
56 | const char* line; |
57 | unsigned line_len; |
58 | |
59 | // Try to read next line. |
60 | if (pop_count_ >= 0) { |
61 | line_reader_.PopLine(pop_count_); |
62 | pop_count_ = -1; |
63 | } |
64 | |
65 | if (!line_reader_.GetNextLine(&line, &line_len)) |
66 | return false; |
67 | |
68 | pop_count_ = static_cast<int>(line_len); |
69 | |
70 | const char* line_end = line + line_len; |
71 | |
72 | // Expected format: <field-name> <space>+ ':' <space> <value> |
73 | // Note that: |
74 | // - empty lines happen. |
75 | // - <field-name> can contain spaces. |
76 | // - some fields have an empty <value> |
77 | char* sep = static_cast<char*>(my_memchr(line, ':', line_len)); |
78 | if (sep == NULL) |
79 | continue; |
80 | |
81 | // Record the value. Skip leading space after the column to get |
82 | // its start. |
83 | const char* val = sep+1; |
84 | while (val < line_end && my_isspace(*val)) |
85 | val++; |
86 | |
87 | value_ = val; |
88 | value_len_ = static_cast<size_t>(line_end - val); |
89 | |
90 | // Remove trailing spaces before the column to properly 0-terminate |
91 | // the field name. |
92 | while (sep > line && my_isspace(sep[-1])) |
93 | sep--; |
94 | |
95 | if (sep == line) |
96 | continue; |
97 | |
98 | // zero-terminate field name. |
99 | *sep = '\0'; |
100 | |
101 | *field = line; |
102 | return true; |
103 | } |
104 | } |
105 | |
106 | // Return the field value. This must be called after a succesful |
107 | // call to GetNextField(). |
108 | const char* GetValue() { |
109 | assert(value_); |
110 | return value_; |
111 | } |
112 | |
113 | // Same as GetValue(), but also returns the length in characters of |
114 | // the value. |
115 | const char* GetValueAndLen(size_t* length) { |
116 | assert(value_); |
117 | *length = value_len_; |
118 | return value_; |
119 | } |
120 | |
121 | private: |
122 | LineReader line_reader_; |
123 | int pop_count_; |
124 | const char* value_; |
125 | size_t value_len_; |
126 | }; |
127 | |
128 | } // namespace google_breakpad |
129 | |
130 | #endif // CLIENT_LINUX_MINIDUMP_WRITER_PROC_CPUINFO_READER_H_ |
131 | |