Line data    Source code

       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 "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           0 :   ProcCpuInfoReader(int fd)
      48           0 :     : line_reader_(fd), pop_count_(-1) {
      49           0 :   }
      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           0 :   bool GetNextField(const char** field) {
      55             :     for (;;) {
      56             :       const char* line;
      57             :       unsigned line_len;
      58             : 
      59             :       // Try to read next line.
      60           0 :       if (pop_count_ >= 0) {
      61           0 :         line_reader_.PopLine(pop_count_);
      62           0 :         pop_count_ = -1;
      63             :       }
      64             : 
      65           0 :       if (!line_reader_.GetNextLine(&line, &line_len))
      66           0 :         return false;
      67             : 
      68           0 :       pop_count_ = static_cast<int>(line_len);
      69             : 
      70           0 :       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           0 :       char* sep = static_cast<char*>(my_memchr(line, ':', line_len));
      78           0 :       if (sep == NULL)
      79           0 :         continue;
      80             : 
      81             :       // Record the value. Skip leading space after the column to get
      82             :       // its start.
      83           0 :       const char* val = sep+1;
      84           0 :       while (val < line_end && my_isspace(*val))
      85           0 :         val++;
      86             : 
      87           0 :       value_ = val;
      88           0 :       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           0 :       while (sep > line && my_isspace(sep[-1]))
      93           0 :         sep--;
      94             : 
      95           0 :       if (sep == line)
      96           0 :         continue;
      97             : 
      98             :       // zero-terminate field name.
      99           0 :       *sep = '\0';
     100             : 
     101           0 :       *field = line;
     102           0 :       return true;
     103           0 :     }
     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           0 :   const char* GetValueAndLen(size_t* length) {
     116           0 :     assert(value_);
     117           0 :     *length = value_len_;
     118           0 :     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_