1  // Copyright 2012 Google LLC
  2  //
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 11  // in the documentation and/or other materials provided with the
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 27  // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 28  
 29  // linux_core_dumper.h: Define the google_breakpad::LinuxCoreDumper
 30  // class, which is derived from google_breakpad::LinuxDumper to extract
 31  // information from a crashed process via its core dump and proc files.
 32  
 33  #ifndef CLIENT_LINUX_MINIDUMP_WRITER_LINUX_CORE_DUMPER_H_
 34  #define CLIENT_LINUX_MINIDUMP_WRITER_LINUX_CORE_DUMPER_H_
 35  
 36  #include "client/linux/minidump_writer/linux_dumper.h"
 37  #include "common/linux/elf_core_dump.h"
 38  #include "common/linux/memory_mapped_file.h"
 39  
 40  namespace google_breakpad {
 41  
 42  class LinuxCoreDumper : public LinuxDumper {
 43   public:
 44    // Constructs a dumper for extracting information of a given process
 45    // with a process ID of |pid| via its core dump file at |core_path| and
 46    // its proc files at |procfs_path|. If |procfs_path| is a copy of
 47    // /proc/<pid>, it should contain the following files:
 48    //     auxv, cmdline, environ, exe, maps, status
 49    // See LinuxDumper for the purpose of |root_prefix|.
 50    LinuxCoreDumper(pid_t pid, const char* core_path, const char* procfs_path,
 51                    const char* root_prefix = "");
 52  
 53    // Implements LinuxDumper::BuildProcPath().
 54    // Builds a proc path for a certain pid for a node (/proc/<pid>/<node>).
 55    // |path| is a character array of at least NAME_MAX bytes to return the
 56    // result.|node| is the final node without any slashes. Return true on
 57    // success.
 58    //
 59    // As this dumper performs a post-mortem dump and makes use of a copy
 60    // of the proc files of the crashed process, this derived method does
 61    // not actually make use of |pid| and always returns a subpath of
 62    // |procfs_path_| regardless of whether |pid| corresponds to the main
 63    // process or a thread of the process, i.e. assuming both the main process
 64    // and its threads have the following proc files with the same content:
 65    //     auxv, cmdline, environ, exe, maps, status
 66    virtual bool BuildProcPath(char* path, pid_t pid, const char* node) const;
 67  
 68    // Implements LinuxDumper::CopyFromProcess().
 69    // Copies content of |length| bytes from a given process |child|,
 70    // starting from |src|, into |dest|. This method extracts the content
 71    // the core dump and fills |dest| with a sequence of marker bytes
 72    // if the expected data is not found in the core dump. Returns true if
 73    // the expected data is found in the core dump.
 74    virtual bool CopyFromProcess(void* dest, pid_t child, const void* src,
 75                                 size_t length);
 76  
 77    // Implements LinuxDumper::GetThreadInfoByIndex().
 78    // Reads information about the |index|-th thread of |threads_|.
 79    // Returns true on success. One must have called |ThreadsSuspend| first.
 80    virtual bool GetThreadInfoByIndex(size_t index, ThreadInfo* info);
 81  
 82    // Implements LinuxDumper::IsPostMortem().
 83    // Always returns true to indicate that this dumper performs a
 84    // post-mortem dump of a crashed process via a core dump file.
 85    virtual bool IsPostMortem() const;
 86  
 87    // Implements LinuxDumper::ThreadsSuspend().
 88    // As the dumper performs a post-mortem dump via a core dump file,
 89    // there is no threads to suspend. This method does nothing and
 90    // always returns true.
 91    virtual bool ThreadsSuspend();
 92  
 93    // Implements LinuxDumper::ThreadsResume().
 94    // As the dumper performs a post-mortem dump via a core dump file,
 95    // there is no threads to resume. This method does nothing and
 96    // always returns true.
 97    virtual bool ThreadsResume();
 98  
 99   protected:
100    // Implements LinuxDumper::EnumerateThreads().
101    // Enumerates all threads of the given process into |threads_|.
102    virtual bool EnumerateThreads();
103  
104   private:
105    // Path of the core dump file.
106    const char* core_path_;
107  
108    // Path of the directory containing the proc files of the given process,
109    // which is usually a copy of /proc/<pid>.
110    const char* procfs_path_;
111  
112    // Memory-mapped core dump file at |core_path_|.
113    MemoryMappedFile mapped_core_file_;
114  
115    // Content of the core dump file.
116    ElfCoreDump core_;
117  
118    // Thread info found in the core dump file.
119    wasteful_vector<ThreadInfo> thread_infos_;
120  };
121  
122  }  // namespace google_breakpad
123  
124  #endif  // CLIENT_LINUX_HANDLER_LINUX_CORE_DUMPER_H_