Re: [PATCH net-next v7 1/4] scm: add SO_PASSPIDFD and SCM_PIDFD

From: Eric Dumazet
Date: Mon Jun 12 2023 - 05:26:25 EST


On Thu, Jun 8, 2023 at 10:26 PM Alexander Mikhalitsyn
<aleksandr.mikhalitsyn@xxxxxxxxxxxxx> wrote:
>
> Implement SCM_PIDFD, a new type of CMSG type analogical to SCM_CREDENTIALS,
> but it contains pidfd instead of plain pid, which allows programmers not
> to care about PID reuse problem.
>
> We mask SO_PASSPIDFD feature if CONFIG_UNIX is not builtin because
> it depends on a pidfd_prepare() API which is not exported to the kernel
> modules.
>
> Idea comes from UAPI kernel group:
> https://uapi-group.org/kernel-features/
>
> Big thanks to Christian Brauner and Lennart Poettering for productive
> discussions about this.
>
> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> Cc: Eric Dumazet <edumazet@xxxxxxxxxx>
> Cc: Jakub Kicinski <kuba@xxxxxxxxxx>
> Cc: Paolo Abeni <pabeni@xxxxxxxxxx>
> Cc: Leon Romanovsky <leon@xxxxxxxxxx>
> Cc: David Ahern <dsahern@xxxxxxxxxx>
> Cc: Arnd Bergmann <arnd@xxxxxxxx>
> Cc: Kees Cook <keescook@xxxxxxxxxxxx>
> Cc: Christian Brauner <brauner@xxxxxxxxxx>
> Cc: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
> Cc: Lennart Poettering <mzxreary@xxxxxxxxxxx>
> Cc: Luca Boccassi <bluca@xxxxxxxxxx>
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Cc: netdev@xxxxxxxxxxxxxxx
> Cc: linux-arch@xxxxxxxxxxxxxxx
> Tested-by: Luca Boccassi <bluca@xxxxxxxxxx>
> Reviewed-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
> Reviewed-by: Christian Brauner <brauner@xxxxxxxxxx>
> Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@xxxxxxxxxxxxx>
> ---

Reviewed-by: Eric Dumazet <edumazet@xxxxxxxxxx>