From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Howells Date: Fri, 15 May 2020 16:20:02 +0100 Subject: [Ocfs2-devel] [PATCH 27/33] sctp: export sctp_setsockopt_bindx In-Reply-To: <20200514062820.GC8564@lst.de> References: <20200514062820.GC8564@lst.de> <20200513062649.2100053-1-hch@lst.de> <20200513062649.2100053-28-hch@lst.de> <20200513180058.GB2491@localhost.localdomain> Message-ID: <129070.1589556002@warthog.procyon.org.uk> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Christoph Hellwig Cc: Marcelo Ricardo Leitner , linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org, dhowells@redhat.com, linux-sctp@vger.kernel.org, target-devel@vger.kernel.org, linux-afs@lists.infradead.org, linux-cifs@vger.kernel.org, rds-devel@oss.oracle.com, linux-rdma@vger.kernel.org, cluster-devel@redhat.com, Jakub Kicinski , linux-block@vger.kernel.org, Alexey Kuznetsov , drbd-dev@tron.linbit.com, ceph-devel@vger.kernel.org, linux-nfs@vger.kernel.org, Neil Horman , Hideaki YOSHIFUJI , netdev@vger.kernel.org, Vlad Yasevich , Eric Dumazet , Jon Maloy , Ying Xue , "David S. Miller" , ocfs2-devel@oss.oracle.com Christoph Hellwig wrote: > > The advantage on using kernel_setsockopt here is that sctp module will > > only be loaded if dlm actually creates a SCTP socket. With this > > change, sctp will be loaded on setups that may not be actually using > > it. It's a quite big module and might expose the system. > > True. Not that the intent is to kill kernel space callers of setsockopt, > as I plan to remove the set_fs address space override used for it. For getsockopt, does it make sense to have the core kernel load optval/optlen into a buffer before calling the protocol driver? Then the driver need not see the userspace pointer at all. Similar could be done for setsockopt - allocate a buffer of the size requested by the user inside the kernel and pass it into the driver, then copy the data back afterwards. David