Re: [RFC PATCH] samples/landlock: Fix building on musl libc

From: Mickaël Salaün
Date: Tue Jul 01 2025 - 04:51:32 EST


On Tue, Jul 01, 2025 at 02:02:48AM +0530, Brahmajit Das wrote:
> Building with make allyesconfig on musl results in the following
>
> In file included from samples/landlock/sandboxer.c:22:
> /usr/include/sys/prctl.h:88:8: error: redefinition of 'struct prctl_mm_map'
> 88 | struct prctl_mm_map {
> | ^~~~~~~~~~~~
> In file included from samples/landlock/sandboxer.c:16:
> usr/include/linux/prctl.h:134:8: note: originally defined here
> 134 | struct prctl_mm_map {
> | ^~~~~~~~~~~~
>
> This is mainly due to differnece in the sys/prctl.h between glibC and
> musl. The struct prctl_mm_map is defined in sys/prctl.h in musl.
>
> Signed-off-by: Brahmajit Das <listout@xxxxxxxxxxx>

Thanks, applied to my -next tree. I just moved down the if/include/endif
block.

I tested it with check-linux.sh from
https://github.com/landlock-lsm/landlock-test-tools
ARCH=x86_64 CC=musl-gcc check-linux.sh build

> ---
> samples/landlock/sandboxer.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/samples/landlock/sandboxer.c b/samples/landlock/sandboxer.c
> index 4e2854c6f9a3..3cc990618f5b 100644
> --- a/samples/landlock/sandboxer.c
> +++ b/samples/landlock/sandboxer.c
> @@ -13,7 +13,9 @@
> #include <errno.h>
> #include <fcntl.h>
> #include <linux/landlock.h>
> +#if defined(__GLIBC__)
> #include <linux/prctl.h>
> +#endif
> #include <linux/socket.h>
> #include <stddef.h>
> #include <stdio.h>
> --
> 2.50.0
>
>