[HDFS-15922] Use memcpy for copying non-null terminated string in jni_helper.c

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.4.0
• Fix Version/s: 3.4.0
• Component/s: libhdfs++
• Labels: pull-request-available
• Hadoop Flags: Reviewed
• Assignee: Gautham Banasandra
• Reporter: Gautham Banasandra
• Due: 26/Mar/21
• Created: 25/Mar/21 16:04
• Updated: 29/Mar/21 17:36
• Resolved: 26/Mar/21 16:26

Description

We currently get a warning while compiling HDFS native client -

[WARNING]     inlined from 'wildcard_expandPath' at /home/jenkins/jenkins-home/workspace/hadoop-multibranch_PR-2792/src/hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfs/jni_helper.c:427:21,
[WARNING] /usr/include/x86_64-linux-gnu/bits/string_fortified.h:106:10: warning: '__builtin_strncpy' output truncated before terminating nul copying as many bytes from a string as its length [-Wstringop-truncation]
[WARNING] /home/jenkins/jenkins-home/workspace/hadoop-multibranch_PR-2792/src/hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfs/jni_helper.c:402:43: note: length computed here

The scenario here is such that the copied string is deliberately not null terminated, since we want to insert a PATH_SEPARATOR ourselves. The warning reported by strncpy is valid, but not applicable in this scenario. Thus, we need to use memcpy which doesn't mind if the string is null terminated or not.

Issue Links

• relates to: HDFS-15935 Use memcpy for copying non-null terminated string
• links to: GitHub Pull Request #2818