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

[Tyler Hicks]

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 âtracer_ptraceâ:
> seccomp_bpf.c:1792:20: error: âPTRACE_EVENTMSG_SYSCALL_ENTRYâ undeclared (first use in this function); did you mean âPTRACE_EVENT_CLONEâ?
>   EXPECT_EQ(entry ? PTRACE_EVENTMSG_SYSCALL_ENTRY
>                     ^
> ../kselftest_harness.h:608:13: note: in definition of macro â__EXPECTâ
>   __typeof__(_expected) __exp = (_expected); \
>              ^~~~~~~~~
> seccomp_bpf.c:1792:2: note: in expansion of macro âEXPECT_EQâ
>   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 â__EXPECTâ
>   __typeof__(_expected) __exp = (_expected); \
>              ^~~~~~~~~
> seccomp_bpf.c:1792:2: note: in expansion of macro âEXPECT_EQâ
>   EXPECT_EQ(entry ? PTRACE_EVENTMSG_SYSCALL_ENTRY
>   ^~~~~~~~~
> seccomp_bpf.c:1793:6: error: âPTRACE_EVENTMSG_SYSCALL_EXITâ undeclared (first use in this function); did you mean âPTRACE_EVENTMSG_SYSCALL_ENTRYâ?
>     : PTRACE_EVENTMSG_SYSCALL_EXIT, msg);
>       ^
> ../kselftest_harness.h:608:13: note: in definition of macro â__EXPECTâ
>   __typeof__(_expected) __exp = (_expected); \
>              ^~~~~~~~~
> seccomp_bpf.c:1792:2: note: in expansion of macro âEXPECT_EQâ
>   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@xxxxxxxxxxxxx>

Tyler

> Signed-off-by: Christian Brauner <christian.brauner@xxxxxxxxxx>
> Cc: Kees Cook <keescook@xxxxxxxxxxxx>
> Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
> Cc: Will Drewry <wad@xxxxxxxxxxxx>
> Cc: Shuah Khan <shuah@xxxxxxxxxx>
> Cc: Alexei Starovoitov <ast@xxxxxxxxxx>
> Cc: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
> Cc: Martin KaFai Lau <kafai@xxxxxx>
> Cc: Song Liu <songliubraving@xxxxxx>
> Cc: Yonghong Song <yhs@xxxxxx>
> Cc: Tycho Andersen <tycho@xxxxxxxx>
> CC: Tyler Hicks <tyhicks@xxxxxxxxxxxxx>
> Cc: Jann Horn <jannh@xxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> Cc: linux-kselftest@xxxxxxxxxxxxxxx
> Cc: netdev@xxxxxxxxxxxxxxx
> Cc: bpf@xxxxxxxxxxxxxxx
> ---
>  tools/testing/selftests/seccomp/seccomp_bpf.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c
> index 6ef7f16c4cf5..ee52eab01800 100644
> --- a/tools/testing/selftests/seccomp/seccomp_bpf.c
> +++ b/tools/testing/selftests/seccomp/seccomp_bpf.c
> @@ -155,6 +155,14 @@ struct seccomp_data {
>  #ifndef PTRACE_SECCOMP_GET_METADATA
>  #define PTRACE_SECCOMP_GET_METADATA	0x420d
>  
> +#ifndef PTRACE_EVENTMSG_SYSCALL_ENTRY
> +#define PTRACE_EVENTMSG_SYSCALL_ENTRY 1
> +#endif
> +
> +#ifndef PTRACE_EVENTMSG_SYSCALL_EXIT
> +#define PTRACE_EVENTMSG_SYSCALL_EXIT 2
> +#endif
> +
>  struct seccomp_metadata {
>  	__u64 filter_off;       /* Input: which filter */
>  	__u64 flags;             /* Output: filter's flags */
> -- 
> 2.23.0
>