On 2015/07/07 13:00, Vince Weaver wrote: > On Tue, 7 Jul 2015, Masami Hiramatsu wrote: > >> On 2015/07/07 6:27, Vince Weaver wrote: >>> Hello >>> >>> I've been working on trying to get the perf_fuzzer to start fuzzing the >>> PERF_EVENT_IOC_SET_BPF so I've added some really hackish kprobe support. >>> >>> However before I can get to the BPF testing the kprobe code generates a >>> constant stream of WARNINGS which make the machine more or less useless >>> until I stop it. I've included a small selection here. >>> >>> Is this expected? >> >> Did you get same message without BPF hack? And also, could you tell us >> your kernel version and configuration? > > It's a Hawell machine running 4.2-rc1. I can post the .config if it's of > interest.
Yes, I'm interested in. > Well the BPF hack is in the fuzzer, not the kernel. And it's not really a > hack, it just turned out to be a huge pain to figure out how to > manually create a valid BPF program in conjunction with a valid kprobe > event. > > I did have to sprinkle printks in the kprobe and bpf code to find out > where various EINVAL returns were coming from, so potentially this is just > a problem of printks happening where they shouldn't. I'll remove those > changes and try to reproduce this tomorrow. OK, and also, if you have a chance, please run the ftracetest as below. $ cd tools/testing/selftest/ftrace/ $ sudo ./ftracetest This will do a series of basic tests on ftrace and report it. > This is possibly a long standing issue, until now I never ran the fuzzer > as root so these particular code paths weren't tested. Thanks, -- Masami HIRAMATSU Linux Technology Research Center, System Productivity Research Dept. Center for Technology Innovation - Systems Engineering Hitachi, Ltd., Research & Development Group E-mail: masami.hiramatsu...@hitachi.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
