Subject: Re: [PATCH bpf-next v2 1/6] bpf: change logging calls from verbose() to bpf_log() and use log pointer

From: Dan Carpenter <[email-masked]>
Date: Thu, 16 Jul 2020 13:10:42 +0300

Hi Toke,

url:    https://github.com/0day-ci/linux/commits/Toke-H-iland-J-rgensen/bpf-Support-multi-attach-for-freplace-programs/20200715-211145
base:   https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
config: x86_64-randconfig-m001-20200715 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-14) 9.3.0

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <[email-masked]>
Reported-by: Dan Carpenter <[email-masked]>

smatch warnings:
include/linux/bpf_verifier.h:351 bpf_verifier_log_needed() error: we previously assumed 'log' could be null (see line 350)
include/linux/bpf_verifier.h:351 bpf_verifier_log_needed() error: we previously assumed 'log' could be null (see line 350)

# https://github.com/0day-ci/linux/commit/e33243ff1dd2cbb3628e4044dd9e00a6abf99c7e
git remote add linux-review https://github.com/0day-ci/linux
git remote update linux-review
git checkout e33243ff1dd2cbb3628e4044dd9e00a6abf99c7e
vim +/log +351 include/linux/bpf_verifier.h

06ee7115b0d174 Alexei Starovoitov     2019-04-01  347  
77d2e05abd4588 Martin KaFai Lau       2018-03-24  348  static inline bool bpf_verifier_log_needed(const struct bpf_verifier_log *log)
77d2e05abd4588 Martin KaFai Lau       2018-03-24  349  {
e33243ff1dd2cb Toke Høiland-Jørgensen 2020-07-15 @350  	return (log && log->level && log->ubuf && !bpf_verifier_log_full(log)) ||
                                                                ^^^
If "log" is NULL

8580ac9404f624 Alexei Starovoitov     2019-10-15 @351  		log->level == BPF_LOG_KERNEL;
                                                                ^^^^^^^^^^
then we are toasted.

77d2e05abd4588 Martin KaFai Lau       2018-03-24  352  }
77d2e05abd4588 Martin KaFai Lau       2018-03-24  353  

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0-DAY CI Kernel Test Service, Intel Corporation
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