refactor(apport): Make public variable pidstat private

Make public variable `pidstat` private and pass it around where needed.

Signed-off-by: Benjamin Drung <benjamin.drung@canonical.com>

data/apport

@@ -108,9 +108,6 @@ def check_lock():
         signal.signal(signal.SIGALRM, original_handler)
 
 
-pidstat = None
-
-
 def get_core_path(
     options: argparse.Namespace,
     crash_user: UserGroupID,
@@ -123,12 +120,8 @@ def get_core_path(
     )[1]
 
 
-def get_pid_info(proc_pid: ProcPid) -> UserGroupID:
+def get_pid_info(proc_pid: ProcPid) -> typing.Tuple[UserGroupID, os.stat_result]:
     """Read /proc information about pid"""
-
-    # pylint: disable=global-statement
-    global pidstat
-
     # unhandled exceptions on missing or invalidly formatted files are okay
     # here -- we want to know in the log file
     pidstat = os.stat("stat", dir_fd=proc_pid.fd)
@@ -142,7 +135,7 @@ def get_pid_info(proc_pid: ProcPid) -> UserGroupID:
 
     assert crash_uid is not None, "failed to parse Uid"
     assert crash_gid is not None, "failed to parse Gid"
-    return UserGroupID(crash_uid, crash_gid)
+    return UserGroupID(crash_uid, crash_gid), pidstat
 
 
 def get_process_starttime(proc_pid: ProcPid) -> int:
@@ -237,6 +230,7 @@ def write_user_coredump(
     limit: int,
     proc_pid: ProcPid,
     crash_user: UserGroupID,
+    pidstat: os.stat_result,
     coredump_fd=None,
     from_report=None,
 ) -> None:
@@ -257,7 +251,6 @@ def write_user_coredump(
     # (suid_dumpable==2 and core_pattern restrictions); when this happens,
     # /proc/pid/stat is owned by root (or the user suid'ed to), but we already
     # changed to the crashed process' uid
-    assert pidstat, "pidstat not initialized"
     if UserGroupID(pidstat.st_uid, pidstat.st_gid) != crash_user:
         logger.error("disabling core dump for suid/sgid/unreadable executable")
         return
@@ -917,7 +910,7 @@ def process_crash_with_proc_pid(options: argparse.Namespace, proc_pid: ProcPid)
     logger = logging.getLogger()
 
     coredump_fd = sys.stdin.fileno()
-    crash_user = get_pid_info(proc_pid)
+    crash_user, pidstat = get_pid_info(proc_pid)
 
     process_start = get_process_starttime(proc_pid)
     if not consistency_checks(options, process_start, proc_pid, crash_user):
@@ -937,7 +930,9 @@ def process_crash_with_proc_pid(options: argparse.Namespace, proc_pid: ProcPid)
 
     # ignore SIGQUIT (it's usually deliberately generated by users)
     if options.signal_number == int(signal.SIGQUIT):
-        write_user_coredump(core_path, core_ulimit, proc_pid, crash_user, coredump_fd)
+        write_user_coredump(
+            core_path, core_ulimit, proc_pid, crash_user, pidstat, coredump_fd
+        )
         return 0
 
     info = apport.report.Report("Crash")
@@ -994,7 +989,7 @@ def process_crash_with_proc_pid(options: argparse.Namespace, proc_pid: ProcPid)
             # check if the user wants a core dump
             recover_privileges()
             write_user_coredump(
-                core_path, core_ulimit, proc_pid, crash_user, coredump_fd
+                core_path, core_ulimit, proc_pid, crash_user, pidstat, coredump_fd
             )
             return 0
 
@@ -1006,7 +1001,9 @@ def process_crash_with_proc_pid(options: argparse.Namespace, proc_pid: ProcPid)
             options.signal_number,
         )
         recover_privileges()
-        write_user_coredump(core_path, core_ulimit, proc_pid, crash_user, coredump_fd)
+        write_user_coredump(
+            core_path, core_ulimit, proc_pid, crash_user, pidstat, coredump_fd
+        )
         return 0
 
     if info.check_ignored():
@@ -1042,7 +1039,7 @@ def process_crash_with_proc_pid(options: argparse.Namespace, proc_pid: ProcPid)
             if skip_msg:
                 logger.error("%s", skip_msg)
                 write_user_coredump(
-                    core_path, core_ulimit, proc_pid, crash_user, coredump_fd
+                    core_path, core_ulimit, proc_pid, crash_user, pidstat, coredump_fd
                 )
                 return 0
             # remove the old file, so that we can create the new one
@@ -1100,7 +1097,7 @@ def process_crash_with_proc_pid(options: argparse.Namespace, proc_pid: ProcPid)
     # than the core size.
     reportfile.seek(0)
     write_user_coredump(
-        core_path, core_ulimit, proc_pid, crash_user, from_report=reportfile
+        core_path, core_ulimit, proc_pid, crash_user, pidstat, from_report=reportfile
     )
     return 0