RFR: 8339331: GCC fortify error in vm_version_linux_aarch64.cpp [v3]

SendaoYan syan at openjdk.org
Tue Dec 17 10:01:20 UTC 2024


> Hi all,
> The file src/hotspot/os_cpu/linux_aarch64/vm_version_linux_aarch64.cpp report nullptr compile warning by gcc14 with fastdebug configure. I think it's false positive, since the statement 'assert(buf != nullptr, "invalid argument");' has make sure the buf should not be nullptr before execute '::read(int, void*, int)'. The call chain is `void VM_Version::initialize_cpu_information(void)` -> `void VM_Version::get_compatible_board(char *buf, int buflen)` -> `static bool read_fully(const char *fname, char *buf, size_t buflen)`, `*buf` is defined as `char  Abstract_VM_Version::_cpu_desc[4096] = {0};` and then right shift 8 bytes, so `*buf` should not be nullptr.
> This PR use guarantee instead of assert to suppress false positive gcc compile warning to make fastdebug configure make success on linux-aarch64 by gcc14.2.0.
> Risk is low.
> 
> Additional testing:
> 
> - [x]  jtreg tests(include tier1/2/3) on linux-x64 with release build
> - [x]  jtreg tests(include tier1/2/3) on linux-x64 with fastdebug build
> - [x]  jtreg tests(include tier1/2/3) on linux-aarch64 with release build
> - [x]  jtreg tests(include tier1/2/3) on linux-aarch64 with fastdebug build

SendaoYan has updated the pull request incrementally with two additional commits since the last revision:

 - revert to "invalid argument"
 - Use PRAGMA_NONNULL_IGNORED to suppress gcc compile warning, and add comments about the gcc bug

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/22655/files
  - new: https://git.openjdk.org/jdk/pull/22655/files/110539b0..5b4e28c7

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=22655&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=22655&range=01-02

  Stats: 7 lines in 1 file changed: 6 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/22655.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22655/head:pull/22655

PR: https://git.openjdk.org/jdk/pull/22655


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