From: Stephen Smalley <sds@tycho.nsa.gov>
To: Paul Moore <paul@paul-moore.com>
Cc: Ondrej Mosnacek <omosnace@redhat.com>,
Jeff Vander Stoep <jeffv@google.com>,
SElinux list <selinux@vger.kernel.org>,
Will Deacon <will@kernel.org>,
"Paul E. McKenney" <paulmck@kernel.org>,
rcu@vger.kernel.org, Jovana Knezevic <jovanak@google.com>
Subject: Re: [PATCH v9] selinux: sidtab: reverse lookup hash table
Date: Fri, 6 Dec 2019 08:45:07 -0500 [thread overview]
Message-ID: <4257992a-e4d8-eff4-3421-61da3376d930@tycho.nsa.gov> (raw)
In-Reply-To: <CAHC9VhQOb5skqQofnrESFuAqfRE1+xq9OD48JcYzq77v0XJsog@mail.gmail.com>
On 12/5/19 7:50 PM, Paul Moore wrote:
> On Thu, Dec 5, 2019 at 1:14 PM Paul Moore <paul@paul-moore.com> wrote:
>> On Thu, Dec 5, 2019 at 1:10 PM Stephen Smalley <sds@tycho.nsa.gov> wrote:
>>> On 12/5/19 12:41 PM, Paul Moore wrote:
>>>> Hmm. I haven't done any debugging yet, but the BPF tests are failing
>>>> (they pass with kernel-5.5.0-0.rc0.git5.1.2.secnext.fc32.x86_64):
>
> ...
>
>>> They all pass for me (with your next-queue branch, using the
>>> selinux-testsuite defconfig fragment merged with the Fedora config).
>>
>> Oh goodie, I'm special :/
>>
>> FWIW, my current test kernel is the next-queue branch rebased on top
>> of Linus' current tree, using the latest config from the secnext
>> kernel builds (Fedora Rawhide + stuff for the test suite).
>>
>>> The error above doesn't look SELinux-related; it looks like your kernel
>>> is rejecting the trivial bpf program used in the test code as being
>>> invalid for some reason.
>>
>> That's where I'm at as well, I'm building an instrumented kernel right
>> now to try and track down the source. I'm sure it is something silly
>> like a messed up kernel config or something, but I'd like to
>> understand *why*.
>
> I traced the "./bpf_test -p" failure down to a BTF check in the BPF
> verifier, there is a comment in that code block which helpfully reads:
> "Either gcc or pahole or kernel are broken.".
>
> :/
>
> The relevant commit is 8580ac9404f6 ("bpf: Process in-kernel BTF"),
> and it appears to be new for v5.5; it isn't present in selinux/next or
> selinux/next-queue. Recompiling with CONFIG_DEBUG_INFO_BTF disabled
> does allow "./bpf_test -p" to succeed, but I hit other BPF test
> failures further along. For reasons I don't understand, the secnext
> kernel builds (which should have this code, and have
> CONFIG_DEBUG_INFO_BTF enabled) are not hitting this problem, but that
> may be due to differences in the build tools on the two systems
> (although they *should* be the same).
>
> Given that we haven't hit -rc1 yet, and everyone else's builds are
> working just fine, I'm going to leave this alone for now. Whatever
> the problems may be, they definitely don't appear to be SELinux
> related.
I re-based next-queue on top of -linus, enabled CONFIG_DEBUG_INFO_BTF,
rebuilt and booted new kernel, did a git clean -fdx in the
selinux-testsuite directory, and built/ran the testsuite; bpf tests
still passed for me. This was on F31.
next prev parent reply other threads:[~2019-12-06 13:45 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-22 9:33 [PATCH v9] selinux: sidtab: reverse lookup hash table Jeff Vander Stoep
2019-11-22 14:21 ` Stephen Smalley
2019-12-03 0:32 ` Paul Moore
2019-12-04 9:11 ` Ondrej Mosnacek
2019-12-04 15:48 ` Stephen Smalley
2019-12-04 23:52 ` Paul Moore
2019-12-05 11:48 ` Ondrej Mosnacek
2019-12-05 14:08 ` Paul Moore
2019-12-05 17:41 ` Paul Moore
2019-12-05 18:10 ` Stephen Smalley
2019-12-05 18:14 ` Paul Moore
2019-12-06 0:50 ` Paul Moore
2019-12-06 13:45 ` Stephen Smalley [this message]
2019-12-06 15:08 ` Paul Moore
2019-12-09 21:17 ` Paul Moore
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