fix(proctree): limit saved file path length

File paths are created by concatting the dentries names from the root to the file, and concattign the file name in the end.
Although each dentry and file name has max length, the entire path has none.
To avoid memorly leakage caused by saving file paths, introduce a limit to the save path length.

pkg/proctree/fileinfo.go

@@ -66,9 +66,19 @@ func (fi *FileInfo) SetFeedAt(feed FileInfoFeed, targetTime time.Time) {
 	fi.setFeedAt(feed, targetTime)
 }
 
+// Paths theoretically has no limit, but we do need to set a limit for the sake of
+// managing memory more responsibly.
+const MaxPathLen = 1024
+
 func (fi *FileInfo) setFeedAt(feed FileInfoFeed, targetTime time.Time) {
 	if feed.Path != "" {
-		fi.path.Set(feed.Path, targetTime)
+		filePath := feed.Path
+		if len(filePath) > MaxPathLen {
+			// Take only the end of the path, as the specific file name and location are the most
+			// important parts.
+			filePath = filePath[len(filePath)-MaxPathLen:]
+		}
+		fi.path.Set(filePath, targetTime)
 	}
 	if feed.Dev >= 0 {
 		fi.dev.Set(feed.Dev, targetTime)