This is a note to let you know that I've just added the patch titled socket: don't clear SOCK_TSTAMP_NEW when SO_TIMESTAMPNS is disabled to the 5.8-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: socket-don-t-clear-sock_tstamp_new-when-so_timestampns-is-disabled.patch and it can be found in the queue-5.8 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Sat Oct 17 08:58:17 AM CEST 2020 From: Christian Eggers <ceggers@xxxxxxx> Date: Mon, 12 Oct 2020 11:35:42 +0200 Subject: socket: don't clear SOCK_TSTAMP_NEW when SO_TIMESTAMPNS is disabled From: Christian Eggers <ceggers@xxxxxxx> [ Upstream commit 4e3bbb33e6f36e4b05be1b1b9b02e3dd5aaa3e69 ] SOCK_TSTAMP_NEW (timespec64 instead of timespec) is also used for hardware time stamps (configured via SO_TIMESTAMPING_NEW). User space (ptp4l) first configures hardware time stamping via SO_TIMESTAMPING_NEW which sets SOCK_TSTAMP_NEW. In the next step, ptp4l disables SO_TIMESTAMPNS(_NEW) (software time stamps), but this must not switch hardware time stamps back to "32 bit mode". This problem happens on 32 bit platforms were the libc has already switched to struct timespec64 (from SO_TIMExxx_OLD to SO_TIMExxx_NEW socket options). ptp4l complains with "missing timestamp on transmitted peer delay request" because the wrong format is received (and discarded). Fixes: 887feae36aee ("socket: Add SO_TIMESTAMP[NS]_NEW") Fixes: 783da70e8396 ("net: add sock_enable_timestamps") Signed-off-by: Christian Eggers <ceggers@xxxxxxx> Acked-by: Willem de Bruijn <willemb@xxxxxxxxxx> Acked-by: Deepa Dinamani <deepa.kernel@xxxxxxxxx> Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/core/sock.c | 1 - 1 file changed, 1 deletion(-) --- a/net/core/sock.c +++ b/net/core/sock.c @@ -777,7 +777,6 @@ static void __sock_set_timestamps(struct } else { sock_reset_flag(sk, SOCK_RCVTSTAMP); sock_reset_flag(sk, SOCK_RCVTSTAMPNS); - sock_reset_flag(sk, SOCK_TSTAMP_NEW); } } Patches currently in stable-queue which might be from ceggers@xxxxxxx are queue-5.8/socket-fix-option-so_timestamping_new.patch queue-5.8/net-dsa-microchip-fix-race-condition.patch queue-5.8/socket-don-t-clear-sock_tstamp_new-when-so_timestampns-is-disabled.patch