python-linux-procfs: Fix when pids complete

- Propagate an error to the user when a pid completes
- Handle a pid disappearing in pflags

Resolves: rhbz#2012288
Signed-off-by: John Kacur <jkacur@redhat.com>

python-linux-procfs-Propagate-error-to-user-if-a-pid.patch

@@ -0,0 +1,68 @@
+From b7ea06b21456d465f2d9d11358fb803eb277357f Mon Sep 17 00:00:00 2001
+From: John Kacur <jkacur@redhat.com>
+Date: Tue, 23 Nov 2021 09:58:58 -0500
+Subject: [PATCH 1/3] python-linux-procfs: Propagate error to user if a pid is
+ completed
+
+If a pid is completed and disappears a FileNotFoundError will occur
+because /proc/pid/stat will disappear too.
+
+It is not possible to check for the file first because it could still
+disappear between the time of the check and the time of use.
+
+Propagate this error to the user.
+The user should handle this with a try, except clause and ignore it if
+an exception occurs.
+
+Signed-off-by: John Kacur <jkacur@redhat.com>
+---
+ procfs/procfs.py | 19 ++++++++++++++++---
+ 1 file changed, 16 insertions(+), 3 deletions(-)
+
+diff --git a/procfs/procfs.py b/procfs/procfs.py
+index 408b2bcd0a31..a0e9977214fe 100755
+--- a/procfs/procfs.py
++++ b/procfs/procfs.py
+@@ -130,7 +130,12 @@ class pidstat:
+ 
+     def __init__(self, pid, basedir="/proc"):
+         self.pid = pid
+-        self.load(basedir)
++        try:
++            self.load(basedir)
++        except FileNotFoundError:
++            # The file representing the pid has disappeared
++            #  propagate the error to the user to handle
++            raise
+ 
+     def __getitem__(self, fieldname):
+         return self.fields[fieldname]
+@@ -151,7 +156,11 @@ class pidstat:
+         return fieldname in self.fields
+ 
+     def load(self, basedir="/proc"):
+-        f = open("%s/%d/stat" % (basedir, self.pid))
++        try:
++            f = open("%s/%d/stat" % (basedir, self.pid))
++        except FileNotFoundError:
++            # The pid has disappeared, propagate the error
++            raise
+         fields = f.readline().strip().split(') ')
+         f.close()
+         fields = fields[0].split(' (') + fields[1].split()
+@@ -338,7 +347,11 @@ class process:
+                 else:
+                     sclass = pidstatus
+ 
+-                setattr(self, attr, sclass(self.pid, self.basedir))
++                try:
++                    setattr(self, attr, sclass(self.pid, self.basedir))
++                except FileNotFoundError:
++                    # The pid has disappeared, progate the error
++                    raise
+             elif attr == "cmdline":
+                 self.load_cmdline()
+             elif attr == "threads":
+-- 
+2.31.1
+

python-linux-procfs-pflags-Handle-pids-that-complete.patch

@@ -0,0 +1,50 @@
+From eb984b30e325bbf27844bf9c1f90767504468db5 Mon Sep 17 00:00:00 2001
+From: John Kacur <jkacur@redhat.com>
+Date: Tue, 23 Nov 2021 13:01:05 -0500
+Subject: [PATCH 2/3] python-linux-procfs: pflags: Handle pids that completed
+
+Sometimes pids disappear when they are completed.
+
+Programs such as pflags that use procfs must account for that.
+The solution is to simply recognize this situation, and to continue.
+
+Signed-off-by: John Kacur <jkacur@redhat.com>
+---
+ pflags | 15 +++++++++++++--
+ 1 file changed, 13 insertions(+), 2 deletions(-)
+
+diff --git a/pflags b/pflags
+index 3407b6f51c96..46d396c87c2b 100755
+--- a/pflags
++++ b/pflags
+@@ -50,14 +50,25 @@ def main(argv):
+         pids = list(ps.processes.keys())
+ 
+     pids.sort()
+-    len_comms = [len(ps[pid]["stat"]["comm"]) for pid in pids if pid in ps]
++    len_comms = []
++    for pid in pids:
++        if pid in ps:
++            try:
++                len(ps[pid]["stat"]["comm"])
++            except (TypeError, FileNotFoundError):
++                continue
++            len_comms.append(len(ps[pid]["stat"]["comm"]))
++
+     max_comm_len = max(len_comms, default=0)
+     del len_comms
+ 
+     for pid in pids:
+         if pid not in ps:
+             continue
+-        flags = ps[pid].stat.process_flags()
++        try:
++            flags = ps[pid].stat.process_flags()
++        except AttributeError:
++            continue
+         # Remove flags that were superseeded
+         if "PF_THREAD_BOUND" in flags and "PF_NO_SETAFFINITY" in flags:
+             flags.remove("PF_THREAD_BOUND")
+-- 
+2.31.1
+

python-linux-procfs.spec

@@ -1,6 +1,6 @@
 Name: python-linux-procfs
 Version: 0.6.3
-Release: 3%{?dist}
+Release: 4%{?dist}
 License: GPLv2
 Summary: Linux /proc abstraction classes
 URL: https://git.kernel.org/pub/scm/libs/python/%{name}/%{name}.git
@@ -14,6 +14,8 @@ Abstractions to extract information from the Linux kernel /proc files.
 
 # PATCHES
 Patch1: python-linux-procfs-Fix-traceback-with-non-utf8-char.patch
+Patch2: python-linux-procfs-Propagate-error-to-user-if-a-pid.patch
+Patch3: python-linux-procfs-pflags-Handle-pids-that-complete.patch
 
 %description %_description
 
@@ -21,7 +23,7 @@ Patch1: python-linux-procfs-Fix-traceback-with-non-utf8-char.patch
 Summary: %summary
 %{?python_provide:%python_provide python3-linux-procfs}
 
-Requires: python3-six
+Requires: python3
 
 %description -n python3-linux-procfs %_description
 
@@ -44,6 +46,11 @@ rm -rf %{buildroot}
 %license COPYING
 
 %changelog
+* Tue Nov 23 2021 John Kacur <jkacur@redhat.com> - 0.6.3-4
+- Propagate error to user if pid completed
+- Handle pid completed in pflags
+Resolves: rhbz#2012288
+
 * Mon Nov 22 2021 John Kacur <jkacur@redhat.com> - 0.6.3-3
 - Fix traceback with non-utf8 chars
 Resolves: rhbz#2022530