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

From: Kees Cook <[email-masked]>
Date: Wed, 18 Sep 2019 10:33:09 -0700

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 <[email-masked]>

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

-- 
Kees Cook