From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: [PATCH v3 net-next 0/2] tcp: mmap: rework zerocopy receive Date: Thu, 26 Apr 2018 07:50:54 -0700 Message-ID: <20180426145056.220325-1-edumazet@google.com> Cc: netdev , Andy Lutomirski , linux-kernel , linux-mm , Ka-Cheong Poon , Eric Dumazet , Eric Dumazet To: "David S . Miller" Return-path: Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org syzbot reported a lockdep issue caused by tcp mmap() support. I implemented Andy Lutomirski nice suggestions to resolve the issue and increase scalability as well. First patch is adding a new getsockopt() operation and changes mmap() behavior. Second patch changes tcp_mmap reference program. v3: change TCP_ZEROCOPY_RECEIVE to be a getsockopt() option instead of setsockopt(), feedback from Ka-Cheon Poon v2: Added a missing page align of zc->length in tcp_zerocopy_receive() Properly clear zc->recv_skip_hint in case user request was completed. Eric Dumazet (2): tcp: add TCP_ZEROCOPY_RECEIVE support for zerocopy receive selftests: net: tcp_mmap must use TCP_ZEROCOPY_RECEIVE include/uapi/linux/tcp.h | 8 ++ net/ipv4/tcp.c | 192 +++++++++++++------------ tools/testing/selftests/net/tcp_mmap.c | 64 +++++---- 3 files changed, 146 insertions(+), 118 deletions(-) -- 2.17.0.484.g0c8726318c-goog