From e979fa412a1763bbf9e3b52fc6d636ad3be8bcc5 Mon Sep 17 00:00:00 2001
From: Vyacheslav Kulakov <kulakov.home@gmail.com>
Date: Tue, 27 Jul 2021 16:23:44 +0300
Subject: [PATCH] Fix data types for ignored stat fields #401

Some ignored fields in the /proc/[pid]/stat file may have values that are bigger than the max value of the current Go type that is used for the ignored variable. That leads to issues in runtime on some systems that use the maximum possible values for the related fields.

See for details:
* https://man7.org/linux/man-pages/man5/proc.5.html
* https://man7.org/linux/man-pages/man3/scanf.3.html

Signed-off-by: Vyacheslav Kulakov <kulakov.home@gmail.com>
---
 proc_stat.go      | 33 +++++++++++++++++----------------
 proc_stat_test.go | 12 ++++++++++++
 2 files changed, 29 insertions(+), 16 deletions(-)

diff --git a/proc_stat.go b/proc_stat.go
index d3a860e4a..8c7b6e80a 100644
--- a/proc_stat.go
+++ b/proc_stat.go
@@ -128,7 +128,8 @@ func (p Proc) Stat() (ProcStat, error) {
 	}
 
 	var (
-		ignore int
+		ignoreInt64  int64
+		ignoreUint64 uint64
 
 		s = ProcStat{PID: p.PID, proc: p.fs}
 		l = bytes.Index(data, []byte("("))
@@ -160,25 +161,25 @@ func (p Proc) Stat() (ProcStat, error) {
 		&s.Priority,
 		&s.Nice,
 		&s.NumThreads,
-		&ignore,
+		&ignoreInt64,
 		&s.Starttime,
 		&s.VSize,
 		&s.RSS,
 		&s.RSSLimit,
-		&ignore,
-		&ignore,
-		&ignore,
-		&ignore,
-		&ignore,
-		&ignore,
-		&ignore,
-		&ignore,
-		&ignore,
-		&ignore,
-		&ignore,
-		&ignore,
-		&ignore,
-		&ignore,
+		&ignoreUint64,
+		&ignoreUint64,
+		&ignoreUint64,
+		&ignoreUint64,
+		&ignoreUint64,
+		&ignoreUint64,
+		&ignoreUint64,
+		&ignoreUint64,
+		&ignoreUint64,
+		&ignoreUint64,
+		&ignoreUint64,
+		&ignoreUint64,
+		&ignoreInt64,
+		&ignoreInt64,
 		&s.RTPriority,
 		&s.Policy,
 		&s.DelayAcctBlkIOTicks,
diff --git a/proc_stat_test.go b/proc_stat_test.go
index eafefb777..53491050e 100644
--- a/proc_stat_test.go
+++ b/proc_stat_test.go
@@ -76,6 +76,18 @@ func TestProcStat(t *testing.T) {
 	}
 }
 
+func TestProcStatIgnored(t *testing.T) {
+	p, err := getProcFixtures(t).Proc(26232)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	_, err = p.Stat()
+	if err != nil {
+		t.Errorf("want not error, have %s", err)
+	}
+}
+
 func TestProcStatComm(t *testing.T) {
 	s1, err := testProcStat(26231)
 	if err != nil {