On Wed, Apr 12, 2023 at 8:31 AM Lorenz Bauer <lmb@xxxxxxxxxxxxx> wrote: > > On Fri, Apr 7, 2023 at 12:42 AM Andrii Nakryiko <andrii@xxxxxxxxxx> wrote: > > > > This patch set changes BPF verifier log behavior to behave as a rotating log, > > by default. If user-supplied log buffer is big enough to contain entire > > verifier log output, there is no effective difference. But where previously > > user supplied too small log buffer and would get -ENOSPC error result and the > > beginning part of the verifier log, now there will be no error and user will > > get ending part of verifier log filling up user-supplied log buffer. Which > > is, in absolute majority of cases, is exactly what's useful, relevant, and > > what users want and need, as the ending of the verifier log is containing > > details of verifier failure and relevant state that got us to that failure. So > > this rotating mode is made default, but for some niche advanced debugging > > scenarios it's possible to request old behavior by specifying additional > > BPF_LOG_FIXED (8) flag. > > I just ran selftest/bpf/test_verifier_log on top of bpf-next which now > fails with: > > Test log_level 0... > Test log_size < 128... > ERROR: Program load returned: ret:-1/errno:28, expected ret:-1/errno:22 > > Seems like these tests are now superseded by test_progs? I didn't even know we have a separate test_verifier_log binary. It seems like newly added tests in test_prog indeed cover all the same use cases. I'll send a patch to remove test_verifier_log.c. Thanks for spotting this!
