[kbuild] fs/afs/cell.c:558:21: warning: use of uninitialized value '<unknown>' [CWE-457]

:::::: :::::: Manual check reason: "low confidence bisect report" :::::: Manual check reason: "low confidence static check warning: fs/afs/cell.c:558:21: warning: use of uninitialized value '<unknown>' [CWE-457] [-Wanalyzer-use-of-uninitialized-value]" :::::: BCC: lkp(a)intel.com CC: kbuild-all(a)lists.01.org CC: linux-kernel(a)vger.kernel.org TO: David Howells <dhowells(a)redhat.com&gt; CC: Marc Dionne <marc.dionne(a)auristor.com&gt; tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 521a547ced6477c54b4b0cc206000406c221b4d6 commit: c56f9ec8b20f931014574b943590c4d830109380 afs: Use refcount_t rather than atomic_t date: 7 weeks ago :::::: branch date: 28 hours ago :::::: commit date: 7 weeks ago config: arm-randconfig-c002-20220917 (https://download.01.org/0day-ci/archive/20220920/202209200839.HnHrDGAT-lk...) compiler: arm-linux-gnueabi-gcc (GCC) 12.1.0 reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit... git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git git fetch --no-tags linus master git checkout c56f9ec8b20f931014574b943590c4d830109380 # save the config file COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross ARCH=arm KBUILD_USERCFLAGS='-fanalyzer -Wno-error' If you fix the issue, kindly add following tag where applicable Reported-by: kernel test robot <lkp(a)intel.com&gt; gcc_analyzer warnings: (new ones prefixed by >>) fs/afs/cell.c: In function 'afs_put_cell': 558 | int r; | ^ 'afs_put_cell': events 1-3 | | 554 | if (cell) { | | ^ | | | | | (1) following 'true' branch (when 'cell' is non-NULL)... |...... | 558 | int r; | | ~ | | | | | (2) ...to here | | (3) use of uninitialized value '<unknown>' here | vim +558 fs/afs/cell.c 8b2a464ced77fe David Howells 2017-11-02 548 ^1da177e4c3f41 Linus Torvalds 2005-04-16 549 /* 989782dcdc91a5 David Howells 2017-11-02 550 * Drop a reference on a cell record. ^1da177e4c3f41 Linus Torvalds 2005-04-16 551 */ dca54a7bbb8ca9 David Howells 2020-10-13 552 void afs_put_cell(struct afs_cell *cell, enum afs_cell_trace reason) 88c853c3f5c0a0 David Howells 2019-07-23 553 { 88c853c3f5c0a0 David Howells 2019-07-23 554 if (cell) { dca54a7bbb8ca9 David Howells 2020-10-13 555 unsigned int debug_id = cell->debug_id; c56f9ec8b20f93 David Howells 2022-07-06 556 unsigned int a; c56f9ec8b20f93 David Howells 2022-07-06 557 bool zero; c56f9ec8b20f93 David Howells 2022-07-06 @558 int r; 88c853c3f5c0a0 David Howells 2019-07-23 559 dca54a7bbb8ca9 David Howells 2020-10-13 560 a = atomic_read(&cell->active); c56f9ec8b20f93 David Howells 2022-07-06 561 zero = __refcount_dec_and_test(&cell->ref, &r); c56f9ec8b20f93 David Howells 2022-07-06 562 trace_afs_cell(debug_id, r - 1, a, reason); c56f9ec8b20f93 David Howells 2022-07-06 563 if (zero) { 88c853c3f5c0a0 David Howells 2019-07-23 564 a = atomic_read(&cell->active); 88c853c3f5c0a0 David Howells 2019-07-23 565 WARN(a != 0, "Cell active count %u > 0\n", a); 88c853c3f5c0a0 David Howells 2019-07-23 566 call_rcu(&cell->rcu, afs_cell_destroy); 88c853c3f5c0a0 David Howells 2019-07-23 567 } 88c853c3f5c0a0 David Howells 2019-07-23 568 } 88c853c3f5c0a0 David Howells 2019-07-23 569 } 88c853c3f5c0a0 David Howells 2019-07-23 570 -- 0-DAY CI Kernel Test Service https://01.org/lkp