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From: Kees Cook <keescook@chromium.org>
Date: Tue, 9 Jan 2018 15:24:26 -0800
Message-ID: <CAGXu5jJLinkSF1yHsz2kFcjxBNFzU-7O-LsDGEHBs+n72bb7CQ@mail.gmail.com>
Subject: Re: [PATCH] selftests: seccomp: fix compile error seccomp_bpf
To: Naresh Kamboju <naresh.kamboju@linaro.org>,
        Shuah Khan <shuah@kernel.org>
Cc: Anders Roxell <anders.roxell@linaro.org>,
        "open list:KERNEL SELFTEST FRAMEWORK" 
        <linux-kselftest@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Will Drewry <wad@chromium.org>,
        Andy Lutomirski <luto@amacapital.net>
Content-Type: text/plain; charset="UTF-8"
Sender: linux-kernel-owner@vger.kernel.org

On Tue, Jan 9, 2018 at 3:07 PM, Kees Cook <keescook@chromium.org> wrote:
> On Fri, Jan 5, 2018 at 6:29 PM, Naresh Kamboju
> <naresh.kamboju@linaro.org> wrote:
>> On 5 January 2018 at 22:01, Anders Roxell <anders.roxell@linaro.org> wrote:
>>> aarch64-linux-gnu-gcc -Wl,-no-as-needed -Wall
>>>     -lpthread seccomp_bpf.c -o seccomp_bpf
>>> seccomp_bpf.c: In function 'tracer_ptrace':
>>> seccomp_bpf.c:1720:12: error: '__NR_open' undeclared
>>>     (first use in this function)
>>>   if (nr == __NR_open)
>>>             ^~~~~~~~~
>>> seccomp_bpf.c:1720:12: note: each undeclared identifier is reported
>>>     only once for each function it appears in
>>> In file included from seccomp_bpf.c:48:0:
>>> seccomp_bpf.c: In function 'TRACE_syscall_ptrace_syscall_dropped':
>>> seccomp_bpf.c:1795:39: error: '__NR_open' undeclared
>>>     (first use in this function)
>>>   EXPECT_SYSCALL_RETURN(EPERM, syscall(__NR_open));
>>>                                        ^
>>> open(2) is a legacy syscall, replaced with openat(2) since 2.6.16.
>>> Thus new architectures in the kernel, such as arm64, don't implement
>>> these legacy syscalls.
>>>
>>> Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
>>
>> Thanks for the patch Anders.
>> Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
>
> Did something change recently? This has built fine on arm64 for a
> while -- at least since commit 256d0afb11d6 ("selftests/seccomp: build
> and pass on arm64").

Ah, found it. I broke it in a33b2d0359a0! :) Shuah, can you take this
please, with this tag added:

Fixes: a33b2d0359a0 ("selftests/seccomp: Add tests for basic ptrace actions")

Thanks!

-Kees

>
> -Kees
>
>>
>>> ---
>>>  tools/testing/selftests/seccomp/seccomp_bpf.c | 4 ++--
>>>  1 file changed, 2 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c
>>> index 24dbf634e2dd..0b457e8e0f0c 100644
>>> --- a/tools/testing/selftests/seccomp/seccomp_bpf.c
>>> +++ b/tools/testing/selftests/seccomp/seccomp_bpf.c
>>> @@ -1717,7 +1717,7 @@ void tracer_ptrace(struct __test_metadata *_metadata, pid_t tracee,
>>>
>>>         if (nr == __NR_getpid)
>>>                 change_syscall(_metadata, tracee, __NR_getppid);
>>> -       if (nr == __NR_open)
>>> +       if (nr == __NR_openat)
>>>                 change_syscall(_metadata, tracee, -1);
>>>  }
>>>
>>> @@ -1792,7 +1792,7 @@ TEST_F(TRACE_syscall, ptrace_syscall_dropped)
>>>                                            true);
>>>
>>>         /* Tracer should skip the open syscall, resulting in EPERM. */
>>> -       EXPECT_SYSCALL_RETURN(EPERM, syscall(__NR_open));
>>> +       EXPECT_SYSCALL_RETURN(EPERM, syscall(__NR_openat));
>>>  }
>>>
>>>  TEST_F(TRACE_syscall, syscall_allowed)
>>> --
>>> 2.11.0
>>>
>
>
>
> --
> Kees Cook
> Pixel Security


-- 
Kees Cook
Pixel Security