Re: [PATCH v3] selftests/landlock:Fix two build issues

[Mickaël Salaün]

On Fri, Jan 12, 2024 at 03:12:45PM +0800, Hu Yadi wrote:
> From: "Hu.Yadi" <hu.yadi@xxxxxxx>
> 
> Two issues comes up while building selftest/landlock on my side
> (gcc 7.3/glibc-2.28/kernel-4.19)
> 
> the first one is as to gettid
> 
> net_test.c: In function ‘set_service’:
> net_test.c:91:45: warning: implicit declaration of function ‘gettid’; [-Wimplicit-function-declaration]
>     "_selftests-landlock-net-tid%d-index%d", gettid(),
>                                              ^~~~~~
>                                              getgid
> net_test.c:(.text+0x4e0): undefined reference to `gettid'
> 
> the second is compiler error
> gcc -Wall -O2 -isystem   fs_test.c -lcap -o selftests/landlock/fs_test
> fs_test.c:4575:9: error: initializer element is not constant
>   .mnt = mnt_tmp,
>          ^~~~~~~
> 
> this patch is to fix them
> 
> Signed-off-by: Hu.Yadi <hu.yadi@xxxxxxx>
> Suggested-by: Jiao <jiaoxupo@xxxxxxx>
> Reviewed-by: Berlin <berlin@xxxxxxx>
> ---
> Changes v3 -> v2:
>  - add helper of gettid instead of __NR_gettid
>  - add gcc/glibc version info in comments
> Changes v1 -> v2:
>  - fix whitespace error
>  - replace SYS_gettid with _NR_gettid
> 
>  tools/testing/selftests/landlock/fs_test.c  | 5 ++++-
>  tools/testing/selftests/landlock/net_test.c | 9 +++++++++
>  2 files changed, 13 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/testing/selftests/landlock/fs_test.c b/tools/testing/selftests/landlock/fs_test.c
> index 18e1f86a6234..a992cf7c0ad1 100644
> --- a/tools/testing/selftests/landlock/fs_test.c
> +++ b/tools/testing/selftests/landlock/fs_test.c
> @@ -4572,7 +4572,10 @@ FIXTURE_VARIANT(layout3_fs)
>  /* clang-format off */
>  FIXTURE_VARIANT_ADD(layout3_fs, tmpfs) {
>  	/* clang-format on */
> -	.mnt = mnt_tmp,
> +	.mnt = {
> +		.type = "tmpfs",
> +		.data = "size=4m,mode=700",

OK, C doesn't play nice with constants. A better approach would be to
define MNT_TMP_DATA, and use it with this fixture variant and the
mnt_tmp variable.  No need for a MNT_TMP_TYPE though.  While you're at
it, you can also make the mnt_tmp variable static const.

You can create two patches from this one. This first hunk with:

Fixes: 04f9070e99a4 ("selftests/landlock: Add tests for pseudo filesystems")

> +	},
>  	.file_path = file1_s1d1,
>  };
>  
> diff --git a/tools/testing/selftests/landlock/net_test.c b/tools/testing/selftests/landlock/net_test.c
> index 929e21c4db05..12a6744568e2 100644
> --- a/tools/testing/selftests/landlock/net_test.c
> +++ b/tools/testing/selftests/landlock/net_test.c
> @@ -21,6 +21,15 @@
>  
>  #include "common.h"

..and this second hunk for another patch with:

Fixes: a549d055a22e ("selftests/landlock: Add network tests")
Cc: Konstantin Meskhidze <konstantin.meskhidze@xxxxxxxxxx>

>  
> +#ifndef gettid
> +static pid_t gettid(void)
> +{
> +        return syscall(__NR_gettid);
> +}
> +

Please remove this newline.

> +#endif

You can move this gettid hunk to common.h, under the
landlock_restrict_self block.

> +
> +
>  const short sock_port_start = (1 << 10);
>  
>  static const char loopback_ipv4[] = "127.0.0.1";
> -- 
> 2.23.0
>