[PATCH net-next v3 6/7] af_unix: enable handing out pidfds for reaped tasks in SCM_PIDFD

Alexander Mikhalitsyn posted 7 patches 3 months ago
[PATCH net-next v3 6/7] af_unix: enable handing out pidfds for reaped tasks in SCM_PIDFD
Posted by Alexander Mikhalitsyn 3 months ago
Now everything is ready to pass PIDFD_STALE to pidfd_prepare().
This will allow opening pidfd for reaped tasks.

Cc: linux-kernel@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Simon Horman <horms@kernel.org>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Kuniyuki Iwashima <kuniyu@google.com>
Cc: Lennart Poettering <mzxreary@0pointer.de>
Cc: Luca Boccassi <bluca@debian.org>
Cc: David Rheinsberg <david@readahead.eu>
Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Reviewed-by: Christian Brauner <brauner@kernel.org>
---
 net/core/scm.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/core/scm.c b/net/core/scm.c
index 358a4e04d46c..072d5742440a 100644
--- a/net/core/scm.c
+++ b/net/core/scm.c
@@ -23,6 +23,7 @@
 #include <linux/security.h>
 #include <linux/pid_namespace.h>
 #include <linux/pid.h>
+#include <uapi/linux/pidfd.h>
 #include <linux/pidfs.h>
 #include <linux/nsproxy.h>
 #include <linux/slab.h>
@@ -482,7 +483,7 @@ static void scm_pidfd_recv(struct msghdr *msg, struct scm_cookie *scm)
 	if (!scm->pid)
 		return;
 
-	pidfd = pidfd_prepare(scm->pid, 0, &pidfd_file);
+	pidfd = pidfd_prepare(scm->pid, PIDFD_STALE, &pidfd_file);
 
 	if (put_cmsg(msg, SOL_SOCKET, SCM_PIDFD, sizeof(int), &pidfd)) {
 		if (pidfd_file) {
-- 
2.43.0
Re: [PATCH net-next v3 6/7] af_unix: enable handing out pidfds for reaped tasks in SCM_PIDFD
Posted by Kuniyuki Iwashima 3 months ago
On Thu, Jul 3, 2025 at 3:24 PM Alexander Mikhalitsyn
<aleksandr.mikhalitsyn@canonical.com> wrote:
>
> Now everything is ready to pass PIDFD_STALE to pidfd_prepare().
> This will allow opening pidfd for reaped tasks.
>
> Cc: linux-kernel@vger.kernel.org
> Cc: netdev@vger.kernel.org
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Eric Dumazet <edumazet@google.com>
> Cc: Jakub Kicinski <kuba@kernel.org>
> Cc: Paolo Abeni <pabeni@redhat.com>
> Cc: Simon Horman <horms@kernel.org>
> Cc: Willem de Bruijn <willemb@google.com>
> Cc: Leon Romanovsky <leon@kernel.org>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Christian Brauner <brauner@kernel.org>
> Cc: Kuniyuki Iwashima <kuniyu@google.com>
> Cc: Lennart Poettering <mzxreary@0pointer.de>
> Cc: Luca Boccassi <bluca@debian.org>
> Cc: David Rheinsberg <david@readahead.eu>
> Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
> Reviewed-by: Christian Brauner <brauner@kernel.org>

Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>

Overall looks good, thanks!
Re: [PATCH net-next v3 6/7] af_unix: enable handing out pidfds for reaped tasks in SCM_PIDFD
Posted by Aleksandr Mikhalitsyn 3 months ago
On Fri, Jul 4, 2025 at 8:38 AM Kuniyuki Iwashima <kuniyu@google.com> wrote:
>
> On Thu, Jul 3, 2025 at 3:24 PM Alexander Mikhalitsyn
> <aleksandr.mikhalitsyn@canonical.com> wrote:
> >
> > Now everything is ready to pass PIDFD_STALE to pidfd_prepare().
> > This will allow opening pidfd for reaped tasks.
> >
> > Cc: linux-kernel@vger.kernel.org
> > Cc: netdev@vger.kernel.org
> > Cc: "David S. Miller" <davem@davemloft.net>
> > Cc: Eric Dumazet <edumazet@google.com>
> > Cc: Jakub Kicinski <kuba@kernel.org>
> > Cc: Paolo Abeni <pabeni@redhat.com>
> > Cc: Simon Horman <horms@kernel.org>
> > Cc: Willem de Bruijn <willemb@google.com>
> > Cc: Leon Romanovsky <leon@kernel.org>
> > Cc: Arnd Bergmann <arnd@arndb.de>
> > Cc: Christian Brauner <brauner@kernel.org>
> > Cc: Kuniyuki Iwashima <kuniyu@google.com>
> > Cc: Lennart Poettering <mzxreary@0pointer.de>
> > Cc: Luca Boccassi <bluca@debian.org>
> > Cc: David Rheinsberg <david@readahead.eu>
> > Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
> > Reviewed-by: Christian Brauner <brauner@kernel.org>
>
> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
>
> Overall looks good, thanks!

Thanks, Kuniyuki for your help and reviews ;-)

Kind regards,
Alex