On Tue, 2023-06-27 at 14:51 +0200, Paolo Abeni wrote: > On Mon, 2023-06-26 at 14:22 -0700, Jakub Kicinski wrote: > > On Mon, 26 Jun 2023 22:14:41 +0100 David Howells wrote: > > > Do you know if ->sendmsg() might alter the msghdr struct it is passed as an > > > argument? Certainly it can alter msg_iter, but can it also modify, > > > say, msg_flags? > > > > I'm not aware of a precedent either way. > > Eric or Paolo would know better than me, tho. > > udp_sendmsg() can set the MSG_TRUNC bit in msg->msg_flags, so I guess > that kind of actions are sort of allowed. Sorry, ENOCOFFEE here. It's actually udp_recvmsg() updating msg- >msg_flags. > Still, AFAICS, the kernel > based msghdr is not copied back to the user-space, so such change > should be almost a no-op in practice. This part should be correct. > @David: which would be the end goal for such action? Sorry for the noisy reply, Paolo
