lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Message-Id: <20230406094245.3633290-19-dhowells@redhat.com> Date: Thu, 6 Apr 2023 10:42:44 +0100 From: David Howells <dhowells@...hat.com> To: netdev@...r.kernel.org Cc: David Howells <dhowells@...hat.com>, "David S. Miller" <davem@...emloft.net>, Eric Dumazet <edumazet@...gle.com>, Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>, Willem de Bruijn <willemdebruijn.kernel@...il.com>, Matthew Wilcox <willy@...radead.org>, Al Viro <viro@...iv.linux.org.uk>, Christoph Hellwig <hch@...radead.org>, Jens Axboe <axboe@...nel.dk>, Jeff Layton <jlayton@...nel.org>, Christian Brauner <brauner@...nel.org>, Chuck Lever III <chuck.lever@...cle.com>, Linus Torvalds <torvalds@...ux-foundation.org>, linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org, linux-mm@...ck.org, Kuniyuki Iwashima <kuniyu@...zon.com> Subject: [PATCH net-next v5 18/19] af_unix: Support MSG_SPLICE_PAGES Make AF_UNIX sendmsg() support MSG_SPLICE_PAGES, splicing in pages from the source iterator if possible and copying the data in otherwise. This allows ->sendpage() to be replaced by something that can handle multiple multipage folios in a single transaction. Signed-off-by: David Howells <dhowells@...hat.com> cc: "David S. Miller" <davem@...emloft.net> cc: Eric Dumazet <edumazet@...gle.com> cc: Jakub Kicinski <kuba@...nel.org> cc: Paolo Abeni <pabeni@...hat.com> cc: Kuniyuki Iwashima <kuniyu@...zon.com> cc: Jens Axboe <axboe@...nel.dk> cc: Matthew Wilcox <willy@...radead.org> cc: netdev@...r.kernel.org --- net/unix/af_unix.c | 93 ++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 77 insertions(+), 16 deletions(-) diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index fb31e8a4409e..fee431a089d3 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -2157,6 +2157,53 @@ static int queue_oob(struct socket *sock, struct msghdr *msg, struct sock *other } #endif +/* + * Extract pages from an iterator and add them to the socket buffer. + */ +static ssize_t unix_extract_bvec_to_skb(struct sk_buff *skb, + struct iov_iter *iter, ssize_t maxsize) +{ + struct page *pages[8], **ppages = pages; + unsigned int i, nr; + ssize_t ret = 0; + + while (iter->count > 0) { + size_t off, len; + + nr = min_t(size_t, MAX_SKB_FRAGS - skb_shinfo(skb)->nr_frags, + ARRAY_SIZE(pages)); + if (nr == 0) + break; + + len = iov_iter_extract_pages(iter, &ppages, maxsize, nr, 0, &off); + if (len <= 0) { + if (!ret) + ret = len ?: -EIO; + break; + } + + i = 0; + do { + size_t part = min_t(size_t, PAGE_SIZE - off, len); + + if (skb_append_pagefrags(skb, pages[i++], off, part) < 0) { + if (!ret) + ret = -EMSGSIZE; + goto out; + } + off = 0; + ret += part; + maxsize -= part; + len -= part; + } while (len > 0); + if (maxsize <= 0) + break; + } + +out: + return ret; +} + static int unix_stream_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) { @@ -2200,19 +2247,25 @@ static int unix_stream_sendmsg(struct socket *sock, struct msghdr *msg, while (sent < len) { size = len - sent; - /* Keep two messages in the pipe so it schedules better */ - size = min_t(int, size, (sk->sk_sndbuf >> 1) - 64); + if (unlikely(msg->msg_flags & MSG_SPLICE_PAGES)) { + skb = sock_alloc_send_pskb(sk, 0, 0, + msg->msg_flags & MSG_DONTWAIT, + &err, 0); + } else { + /* Keep two messages in the pipe so it schedules better */ + size = min_t(int, size, (sk->sk_sndbuf >> 1) - 64); - /* allow fallback to order-0 allocations */ - size = min_t(int, size, SKB_MAX_HEAD(0) + UNIX_SKB_FRAGS_SZ); + /* allow fallback to order-0 allocations */ + size = min_t(int, size, SKB_MAX_HEAD(0) + UNIX_SKB_FRAGS_SZ); - data_len = max_t(int, 0, size - SKB_MAX_HEAD(0)); + data_len = max_t(int, 0, size - SKB_MAX_HEAD(0)); - data_len = min_t(size_t, size, PAGE_ALIGN(data_len)); + data_len = min_t(size_t, size, PAGE_ALIGN(data_len)); - skb = sock_alloc_send_pskb(sk, size - data_len, data_len, - msg->msg_flags & MSG_DONTWAIT, &err, - get_order(UNIX_SKB_FRAGS_SZ)); + skb = sock_alloc_send_pskb(sk, size - data_len, data_len, + msg->msg_flags & MSG_DONTWAIT, &err, + get_order(UNIX_SKB_FRAGS_SZ)); + } if (!skb) goto out_err; @@ -2224,13 +2277,21 @@ static int unix_stream_sendmsg(struct socket *sock, struct msghdr *msg, } fds_sent = true; - skb_put(skb, size - data_len); - skb->data_len = data_len; - skb->len = size; - err = skb_copy_datagram_from_iter(skb, 0, &msg->msg_iter, size); - if (err) { - kfree_skb(skb); - goto out_err; + if (unlikely(msg->msg_flags & MSG_SPLICE_PAGES)) { + size = unix_extract_bvec_to_skb(skb, &msg->msg_iter, size); + skb->data_len += size; + skb->len += size; + skb->truesize += size; + refcount_add(size, &sk->sk_wmem_alloc); + } else { + skb_put(skb, size - data_len); + skb->data_len = data_len; + skb->len = size; + err = skb_copy_datagram_from_iter(skb, 0, &msg->msg_iter, size); + if (err) { + kfree_skb(skb); + goto out_err; + } } unix_state_lock(other);
Powered by blists - more mailing lists