On Thu, Sep 11, 2025 at 2:26 PM Eduard Zingerman <eddyz87@xxxxxxxxx> wrote: > > On Thu, 2025-09-11 at 22:19 +0800, kernel test robot wrote: > > Hi Eduard, > > > > kernel test robot noticed the following build warnings: > > > > [auto build test WARNING on bpf-next/master] > > > > url: https://github.com/intel-lab-lkp/linux/commits/Eduard-Zingerman/bpf-bpf_verifier_state-cleaned-flag-instead-of-REG_LIVE_DONE/20250911-090604 > > base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master > > patch link: https://lore.kernel.org/r/20250911010437.2779173-10-eddyz87%40gmail.com > > patch subject: [PATCH bpf-next v1 09/10] bpf: disable and remove registers chain based liveness > > config: x86_64-buildonly-randconfig-003-20250911 (https://download.01.org/0day-ci/archive/20250911/202509112112.wkWw6wJW-lkp@xxxxxxxxx/config) > > compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261) > > reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250911/202509112112.wkWw6wJW-lkp@xxxxxxxxx/reproduce) > > > > If you fix the issue in a separate patch/commit (i.e. not just a new version of > > the same patch/commit), kindly add following tags > > > Reported-by: kernel test robot <lkp@xxxxxxxxx> > > > Closes: https://lore.kernel.org/oe-kbuild-all/202509112112.wkWw6wJW-lkp@xxxxxxxxx/ > > > > All warnings (new ones prefixed by >>): > > > > > > kernel/bpf/verifier.c:19305:11: warning: variable 'err' is uninitialized when used here [-Wuninitialized] > > 19305 | err = err ? : push_jmp_history(env, cur, 0, 0); > > | ^~~ > > kernel/bpf/verifier.c:19140:12: note: initialize the variable 'err' to silence this warning > > 19140 | int n, err, states_cnt = 0; > > | ^ > > | = 0 > > 1 warning generated. > > > > > > vim +/err +19305 kernel/bpf/verifier.c > > This was sloppy on my side, should look as follows: > > --- a/kernel/bpf/verifier.c > +++ b/kernel/bpf/verifier.c > @@ -19297,9 +19297,12 @@ static int is_state_visited(struct bpf_verifier_env *env, int insn_idx) > * the precision needs to be propagated back in > * the current state. > */ > - if (is_jmp_point(env, env->insn_idx)) > - err = err ? : push_jmp_history(env, cur, 0, 0); > - err = err ? : propagate_precision(env, &sl->state, cur, NULL); > + if (is_jmp_point(env, env->insn_idx)) { > + err = push_jmp_history(env, cur, 0, 0); > + if (err) > + return err; > + } > + err = propagate_precision(env, &sl->state, cur, NULL); hmm. init err=0 instead and avoid explicit if (err)return err ?
