jmx-dev RFR: 8366092: [GCC static analyzer] UnixOperatingSystem.c warning: use of uninitialized value 'systemTicks' [v3]

[Matthias Baesken]

> When using gcc static analyzer (-fanalyzer) with gcc 13.2 the following issue is reported :
> 
> /jdk/src/jdk.management/linux/native/libmanagement_ext/UnixOperatingSystem.c: In function 'get_jvmticks':
> /jdk/src/jdk.management/linux/native/libmanagement_ext/UnixOperatingSystem.c:208:24: warning: use of uninitialized value 'systemTicks' [CWE-457] [-Wanalyzer-use-of-uninitialized-value]
>   208 | pticks->usedKernel = systemTicks;
> 
> 
> vsscanf usually/normally reads the systemTicks info from /proc file system. see
> https://github.com/openjdk/jdk/blob/45726a1f8b8f76586037867a32b82f8ab9b96937/src/jdk.management/linux/native/libmanagement_ext/UnixOperatingSystem.c#L163
> but we never check that the *exact* number of params is read with vsscanf :
> n = vsscanf(tmp, fmt, args);
> So potentially we could get a non complete info without systemTicks and the call would still succeed.

Matthias Baesken has updated the pull request incrementally with one additional commit since the last revision:

  Avoid initialization

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/26962/files
  - new: https://git.openjdk.org/jdk/pull/26962/files/cb0f8dfc..daf31fe6

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=26962&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=26962&range=01-02

  Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/26962.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/26962/head:pull/26962

PR: https://git.openjdk.org/jdk/pull/26962