From: Stas Sergeev <stsp2@xxxxxxxxx> Date: Sat, 16 Nov 2024 13:11:20 +0300 > Currently SCM_PIDFD cmsg cannot be sent via unix socket > (returns -EINVAL) and SO_PASSPIDFD doesn't support flags. > The created pidfd always has flags set to 0. > > This patch implements SCM_PIDFD cmsg in AF_UNIX socket, which > can be used to send flags to SO_PASSPIDFD-enabled recipient. > > Self-test is added for the propagation of PIDFD_NONBLOCK flag. > > This is mainly needed for the future extensions, like eg this one: > https://lore.kernel.org/lkml/8288a08e-448b-43c2-82dc-59f87d0d9072@xxxxxxxxx/T/#me1237e46deba8574b77834b7704e63559ffef9cb > where it was suggested to try solving the supplementary groups > problem with pidfd. > > Changes in v3: specify target tree in patch subject It seems you missed other feedback, especially __scm_recv_common() needs a small change. net-next is closed during the merge window for v6.13-rc1, so please post v4 after Dec 2nd. https://lore.kernel.org/netdev/20241118071654.695bb1a2@xxxxxxxxxx/
