Move some parts of ProcessReader (in snapshot) to ProcessInfo (in util)

util/posix/process_info.h

+// Copyright 2014 The Crashpad Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef CRASHPAD_UTIL_POSIX_PROCESS_INFO_H_
+#define CRASHPAD_UTIL_POSIX_PROCESS_INFO_H_
+
+#include <sys/sysctl.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <set>
+#include <string>
+#include <vector>
+
+#include "base/basictypes.h"
+#include "build/build_config.h"
+#include "util/misc/initialization_state_dcheck.h"
+
+#if defined(OS_MACOSX)
+#include <mach/mach.h>
+#endif
+
+namespace crashpad {
+
+class ProcessInfo {
+ public:
+  ProcessInfo();
+

[Robert Sesek, 2014/11/14 22:06:18]

No dtor?

+  //! \brief Initializes this object with information about the process whose ID
+  //!     is \a pid.
+  //!
+  //! This method must be called successfully prior to calling any other method
+  //! in this class. This method may only be called once.
+  //!
+  //! It is unspecified whether the information that an object of this class
+  //! returns is loaded at the time Initialize() is called or subsequently, and

[Robert Sesek, 2014/11/14 22:06:18]

This consideration then requires that the target process remain alive for the
duration of the object's lifetime, which is fine, but a little odd in a crash
reporting library.

[Mark Mentovai, 2014/11/14 22:16:45]

Robert Sesek wrote:
It should be OK. A crashing process needs to be accessible for the duration that
the reporter deals with it for other purposes as well. The crashing process is
alive but not scheduleable.

I put this comment here because Arguments() doesn’t cache anything. It’s flaky
and needs to be dealt with specially by the caller, if the caller cares.

+  //! whether this information is cached in the object or not.
+  //!
+  //! \param[in] pid The process ID to obtain information for.
+  //!
+  //! \return `true` on success, `false` on failure with a message logged.
+  bool Initialize(pid_t pid);
+
+#if defined(OS_MACOSX) || DOXYGEN
+  //! \brief Initializes this object with information about a process based on
+  //!     its Mach task.
+  //!
+  //! This method serves as a stand-in for Initialize() and may be called in its
+  //! place with the same restrictions and considerations.
+  //!
+  //! \param[in] task The Mach task to obtain information for.
+  //!
+  //! \return `true` on success, `false` on failure with an message logged.
+  bool InitializeFromTask(task_t task);
+#endif
+
+  //! \return The target task’s process ID.
+  pid_t ProcessID() const;
+
+  //! \return The target task’s parent process ID.
+  pid_t ParentProcessID() const;
+
+  //! \return The target process’ real user ID as would be returned to it by
+  //!     `getuid()`.
+  uid_t RealUserID() const;
+
+  //! \return The target process’ effective user ID as would be returned to it
+  //!     by `geteuid()`.
+  uid_t EffectiveUserID() const;
+
+  //! \return The target process’ saved set-user ID.
+  uid_t SavedUserID() const;
+
+  //! \return the target process’ real group ID as would be returned to it by
+  //!     `getgid()`.
+  gid_t RealGroupID() const;
+
+  //! \return the target process’ effective group ID as would be returned to it
+  //!     by `getegid()`.
+  gid_t EffectiveGroupID() const;
+
+  //! \return The target process’ saved set-group ID.
+  gid_t SavedGroupID() const;
+
+  //! \return the target process’ supplementary group list as would be returned
+  //!     to it by `getgroups()`.
+  std::set<gid_t> SupplementaryGroups() const;
+
+  //! \return All groups that the target process claims membership in, including
+  //!     RealGroupID(), EffectiveGroupID(), SavedGroupID(), and
+  //!     SupplementaryGroups().
+  std::set<gid_t> AllGroups() const;
+
+  //! \brief Determines whether the target process has changed privileges.
+  //!
+  //! A process is considered to have changed privileges if it has changed its
+  //! real, effective, or saved set-user or group IDs with the `setuid()`,
+  //! `seteuid()`, `setreuid()`, `setgid()`, `setegid()`, or `setregid()` system
+  //! calls since its most recent `execve()`, or if its privileges changed at
+  //! `execve()` as a result of executing a setuid or setgid executable.
+  bool DidChangePrivileges() const;
+
+  //! \return `true` if the target task is a 64-bit process.
+  bool Is64Bit() const;
+
+  //! \brief Determines the target process’ start time.
+  //!
+  //! \param[out] start_time The time that the process started.
+  void StartTime(timeval* start_time) const;
+
+  //! \brief Obtains the arguments used to launch a process.
+  //!
+  //! Whether it is possible to obtain this information for a process with
+  //! different privileges than the running program is system-dependent.
+  //!
+  //! \param[out] argv The process’ arguments as passed to its `main()` function
+  //!     as the \a argv parameter, possibly modified by the process.
+  //!
+  //! \return `true` on success, with \a argv populated appropriately.
+  //!     Otherwise, `false` with a message logged.
+  //!
+  //! \note This function may spuriously return `false` when used to examine a
+  //!     process that it is calling `exec()`. If examining such a process, call
+  //!     this function in a retry loop with a small (100ns) delay to avoid an
+  //!     erroneous assumption that \a pid is not running.
+  bool Arguments(std::vector<std::string>* argv) const;
+
+ private:
+#if defined(OS_MACOSX)
+  kinfo_proc kern_proc_info_;
+#endif
+  InitializationStateDcheck initialized_;
+
+  DISALLOW_COPY_AND_ASSIGN(ProcessInfo);
+};
+
+}  // namespace crashpad
+
+#endif  // CRASHPAD_UTIL_POSIX_PROCESS_INFO_H_