Re: [PATCH 2/4] seccomp: add two missing ptrace ifdefines

From: "Dmitry V. Levin" <ldv@altlinux.org>
To: Kees Cook <keescook@chromium.org>
Cc: Tyler Hicks <tyhicks@canonical.com>,
	Christian Brauner <christian.brauner@ubuntu.com>,
	luto@amacapital.net, jannh@google.com, wad@chromium.org,
	shuah@kernel.org, ast@kernel.org, daniel@iogearbox.net,
	kafai@fb.com, songliubraving@fb.com, yhs@fb.com,
	linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org,
	netdev@vger.kernel.org, bpf@vger.kernel.org,
	Tycho Andersen <tycho@tycho.ws>,
	stable@vger.kernel.org
Subject: Re: [PATCH 2/4] seccomp: add two missing ptrace ifdefines
Date: Thu, 19 Sep 2019 13:42:51 +0300	[thread overview]
Message-ID: <20190919104251.GA16834@altlinux.org> (raw)
In-Reply-To: <201909181031.1EE73B4@keescook>

On Wed, Sep 18, 2019 at 10:33:09AM -0700, Kees Cook wrote:
> On Wed, Sep 18, 2019 at 11:15:12AM +0200, Tyler Hicks wrote:
> > On 2019-09-18 10:48:31, Christian Brauner wrote:
> > > Add tw missing ptrace ifdefines to avoid compilation errors on systems
> > > that do not provide PTRACE_EVENTMSG_SYSCALL_ENTRY or
> > > PTRACE_EVENTMSG_SYSCALL_EXIT or:
> > > 
> > > gcc -Wl,-no-as-needed -Wall  seccomp_bpf.c -lpthread -o seccomp_bpf
> > > In file included from seccomp_bpf.c:52:0:
> > > seccomp_bpf.c: In function ‘tracer_ptrace’:
> > > seccomp_bpf.c:1792:20: error: ‘PTRACE_EVENTMSG_SYSCALL_ENTRY’ undeclared (first use in this function); did you mean ‘PTRACE_EVENT_CLONE’?
> > >   EXPECT_EQ(entry ? PTRACE_EVENTMSG_SYSCALL_ENTRY
> > >                     ^
> > > ../kselftest_harness.h:608:13: note: in definition of macro ‘__EXPECT’
> > >   __typeof__(_expected) __exp = (_expected); \
> > >              ^~~~~~~~~
> > > seccomp_bpf.c:1792:2: note: in expansion of macro ‘EXPECT_EQ’
> > >   EXPECT_EQ(entry ? PTRACE_EVENTMSG_SYSCALL_ENTRY
> > >   ^~~~~~~~~
> > > seccomp_bpf.c:1792:20: note: each undeclared identifier is reported only once for each function it appears in
> > >   EXPECT_EQ(entry ? PTRACE_EVENTMSG_SYSCALL_ENTRY
> > >                     ^
> > > ../kselftest_harness.h:608:13: note: in definition of macro ‘__EXPECT’
> > >   __typeof__(_expected) __exp = (_expected); \
> > >              ^~~~~~~~~
> > > seccomp_bpf.c:1792:2: note: in expansion of macro ‘EXPECT_EQ’
> > >   EXPECT_EQ(entry ? PTRACE_EVENTMSG_SYSCALL_ENTRY
> > >   ^~~~~~~~~
> > > seccomp_bpf.c:1793:6: error: ‘PTRACE_EVENTMSG_SYSCALL_EXIT’ undeclared (first use in this function); did you mean ‘PTRACE_EVENTMSG_SYSCALL_ENTRY’?
> > >     : PTRACE_EVENTMSG_SYSCALL_EXIT, msg);
> > >       ^
> > > ../kselftest_harness.h:608:13: note: in definition of macro ‘__EXPECT’
> > >   __typeof__(_expected) __exp = (_expected); \
> > >              ^~~~~~~~~
> > > seccomp_bpf.c:1792:2: note: in expansion of macro ‘EXPECT_EQ’
> > >   EXPECT_EQ(entry ? PTRACE_EVENTMSG_SYSCALL_ENTRY
> > >   ^~~~~~~~~
> > > 
> > > Fixes: 6a21cc50f0c7 ("seccomp: add a return code to trap to userspace")
> > 
> > I think this Fixes line is incorrect and should be changed to:
> > 
> > Fixes: 201766a20e30 ("ptrace: add PTRACE_GET_SYSCALL_INFO request")
> > 
> > With that changed,
> > 
> > Reviewed-by: Tyler Hicks <tyhicks@canonical.com>
> 
> This is actually fixed in -next already (and, yes, with the Fixes line
> Tyler has mentioned):
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest.git/commit/?h=next&id=69b2d3c5924273a0ae968d3818210fc57a1b9d07

Excuse me, does it mean that you expect each selftest to be self-hosted?
I was (and still is) under impression that selftests should be built
with headers installed from the tree. Is it the case, or is it not?

-- 
ldv