Re: [PATCH v2] riscv: add support for SECCOMP and SECCOMP_FILTER

From: Kees Cook <keescook@chromium.org>
To: Paul Walmsley <paul.walmsley@sifive.com>
Cc: David Abdurachmanov <david.abdurachmanov@gmail.com>,
	Tycho Andersen <tycho@tycho.ws>,
	Palmer Dabbelt <palmer@sifive.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	Oleg Nesterov <oleg@redhat.com>,
	Andy Lutomirski <luto@amacapital.net>,
	Will Drewry <wad@chromium.org>, Shuah Khan <shuah@kernel.org>,
	Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
	Yonghong Song <yhs@fb.com>,
	David Abdurachmanov <david.abdurachmanov@sifive.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Allison Randal <allison@lohutok.net>,
	Alexios Zavras <alexios.zavras@intel.com>,
	Anup Patel <Anup.Patel@wdc.com>,
	Vincent Chen <vincentc@andestech.com>,
	Alan Kao <alankao@andestech.com>,
	linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
	linux-kselftest@vger.kernel.org, netdev@vger.kernel.org,
	bpf@vger.kernel.org, me@carlosedp.com
Subject: Re: [PATCH v2] riscv: add support for SECCOMP and SECCOMP_FILTER
Date: Sun, 25 Aug 2019 14:51:42 -0700	[thread overview]
Message-ID: <201908251446.04BCB8C@keescook> (raw)
In-Reply-To: <alpine.DEB.2.21.9999.1908231717550.25649@viisi.sifive.com>

On Fri, Aug 23, 2019 at 05:30:53PM -0700, Paul Walmsley wrote:
> On Thu, 22 Aug 2019, David Abdurachmanov wrote:
> 
> > There is one failing kernel selftest: global.user_notification_signal
> 
> Is this the only failing test?  Or are the rest of the selftests skipped 
> when this test fails, and no further tests are run, as seems to be shown 
> here:
> 
>   https://lore.kernel.org/linux-riscv/CADnnUqcmDMRe1f+3jG8SPR6jRrnBsY8VVD70VbKEm0NqYeoicA@mail.gmail.com/
> 
> For example, looking at the source, I'd naively expect to see the 
> user_notification_closed_listener test result -- which follows right 
> after the failing test in the selftest source.  But there aren't any 
> results?
> 
> Also - could you follow up with the author of this failing test to see if 
> we can get some more clarity about what might be going wrong here?  It 
> appears that the failing test was added in commit 6a21cc50f0c7f ("seccomp: 
> add a return code to trap to userspace") by Tycho Andersen 
> <tycho@tycho.ws>.

So, the original email says the riscv series is tested on top of 5.2-rc7,
but just for fun, can you confirm that you're building a tree that includes
9dd3fcb0ab73 ("selftests/seccomp: Handle namespace failures gracefully")? I
assume it does, but I suspect something similar is happening, where the
environment is slightly different than expected and the test stalls.

Does it behave the same way under emulation (i.e. can I hope to
reproduce this myself?)

-- 
Kees Cook