kernel/linux.git/include/net/udp.h, branch v7.0-rc7

Convert more 'alloc_obj' cases to default GFP_KERNEL arguments

2026-02-22T04:03:00+00:00

This converts some of the visually simpler cases that have been split over multiple lines. I only did the ones that are easy to verify the resulting diff by having just that final GFP_KERNEL argument on the next line. Somebody should probably do a proper coccinelle script for this, but for me the trivial script actually resulted in an assertion failure in the middle of the script. I probably had made it a bit _too_ trivial. So after fighting that far a while I decided to just do some of the syntactically simpler cases with variations of the previous 'sed' scripts. The more syntactically complex multi-line cases would mostly really want whitespace cleanup anyway. Signed-off-by: Linus Torvalds

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

udp: udplite is unlikely

2026-01-07T01:06:03+00:00

Add some unlikely() annotations to speed up the fast path, at least with clang compiler. Signed-off-by: Eric Dumazet Link: https://patch.msgid.link/20260105101719.2378881-1-edumazet@google.com Signed-off-by: Jakub Kicinski

net: Convert proto callbacks from sockaddr to sockaddr_unsized

2025-11-05T03:10:33+00:00

Convert struct proto pre_connect(), connect(), bind(), and bind_add() callback function prototypes from struct sockaddr to struct sockaddr_unsized. This does not change per-implementation use of sockaddr for passing around an arbitrarily sized sockaddr struct. Those will be addressed in future patches. Additionally removes the no longer referenced struct sockaddr from include/net/inet_common.h. No binary changes expected. Signed-off-by: Kees Cook Link: https://patch.msgid.link/20251104002617.2752303-5-kees@kernel.org Signed-off-by: Jakub Kicinski

udp: remove busylock and add per NUMA queues

2025-09-23T23:38:39+00:00

busylock was protecting UDP sockets against packet floods, but unfortunately was not protecting the host itself. Under stress, many cpus could spin while acquiring the busylock, and NIC had to drop packets. Or packets would be dropped in cpu backlog if RPS/RFS were in place. This patch replaces the busylock by intermediate lockless queues. (One queue per NUMA node). This means that fewer number of cpus have to acquire the UDP receive queue lock. Most of the cpus can either: - immediately drop the packet. - or queue it in their NUMA aware lockless queue. Then one of the cpu is chosen to process this lockless queue in a batch. The batch only contains packets that were cooked on the same NUMA node, thus with very limited latency impact. Tested: DDOS targeting a victim UDP socket, on a platform with 6 NUMA nodes (Intel(R) Xeon(R) 6985P-C) Before: nstat -n ; sleep 1 ; nstat | grep Udp Udp6InDatagrams 1004179 0.0 Udp6InErrors 3117 0.0 Udp6RcvbufErrors 3117 0.0 After: nstat -n ; sleep 1 ; nstat | grep Udp Udp6InDatagrams 1116633 0.0 Udp6InErrors 14197275 0.0 Udp6RcvbufErrors 14197275 0.0 We can see this host can now proces 14.2 M more packets per second while under attack, and the victim socket can receive 11 % more packets. I used a small bpftrace program measuring time (in us) spent in __udp_enqueue_schedule_skb(). Before: @udp_enqueue_us[398]: [0] 24901 |@@@ | [1] 63512 |@@@@@@@@@ | [2, 4) 344827 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@| [4, 8) 244673 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ | [8, 16) 54022 |@@@@@@@@ | [16, 32) 222134 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ | [32, 64) 232042 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ | [64, 128) 4219 | | [128, 256) 188 | | After: @udp_enqueue_us[398]: [0] 5608855 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@| [1] 1111277 |@@@@@@@@@@ | [2, 4) 501439 |@@@@ | [4, 8) 102921 | | [8, 16) 29895 | | [16, 32) 43500 | | [32, 64) 31552 | | [64, 128) 979 | | [128, 256) 13 | | Note that the remaining bottleneck for this platform is in udp_drops_inc() because we limited struct numa_drop_counters to only two nodes so far. Signed-off-by: Eric Dumazet Acked-by: Paolo Abeni Reviewed-by: Willem de Bruijn Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250922104240.2182559-1-edumazet@google.com Signed-off-by: Jakub Kicinski

net: ipv4: make udp_v4_early_demux explicitly return drop reason

2025-09-20T00:35:51+00:00

udp_v4_early_demux already returns drop reasons as it either returns 0 or ip_mc_validate_source, which itself returns drop reasons. Its return value is also already used as a drop reason itself. Makes this explicit by making it return drop reasons. Signed-off-by: Antoine Tenart Reviewed-by: David Ahern Link: https://patch.msgid.link/20250915091958.15382-2-atenart@kernel.org Signed-off-by: Jakub Kicinski

udp: make busylock per socket

2025-09-18T08:17:10+00:00

While having all spinlocks packed into an array was a space saver, this also caused NUMA imbalance and hash collisions. UDPv6 socket size becomes 1600 after this patch. Signed-off-by: Eric Dumazet Reviewed-by: Willem de Bruijn Reviewed-by: David Ahern Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250916160951.541279-10-edumazet@google.com Reviewed-by: Jakub Kicinski Signed-off-by: Paolo Abeni

udp: add udp_drops_inc() helper

2025-09-18T08:17:10+00:00

Generic sk_drops_inc() reads sk->sk_drop_counters. We know the precise location for UDP sockets. Move sk_drop_counters out of sock_read_rxtx so that sock_write_rxtx starts at a cache line boundary. Signed-off-by: Eric Dumazet Reviewed-by: Willem de Bruijn Reviewed-by: David Ahern Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250916160951.541279-9-edumazet@google.com Reviewed-by: Jakub Kicinski Signed-off-by: Paolo Abeni

udp: add drop_counters to udp socket

2025-08-28T11:14:50+00:00

When a packet flood hits one or more UDP sockets, many cpus have to update sk->sk_drops. This slows down other cpus, because currently sk_drops is in sock_write_rx group. Add a socket_drop_counters structure to udp sockets. Using dedicated cache lines to hold drop counters makes sure that consumers no longer suffer from false sharing if/when producers only change sk->sk_drops. This adds 128 bytes per UDP socket. Tested with the following stress test, sending about 11 Mpps to a dual socket AMD EPYC 7B13 64-Core. super_netperf 20 -t UDP_STREAM -H DUT -l10 -- -n -P,1000 -m 120 Note: due to socket lookup, only one UDP socket is receiving packets on DUT. Then measure receiver (DUT) behavior. We can see both consumer and BH handlers can process more packets per second. Before: nstat -n ; sleep 1 ; nstat | grep Udp Udp6InDatagrams 615091 0.0 Udp6InErrors 3904277 0.0 Udp6RcvbufErrors 3904277 0.0 After: nstat -n ; sleep 1 ; nstat | grep Udp Udp6InDatagrams 816281 0.0 Udp6InErrors 7497093 0.0 Udp6RcvbufErrors 7497093 0.0 Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250826125031.1578842-5-edumazet@google.com Signed-off-by: Paolo Abeni

net: add sk_drops_skbadd() helper

2025-08-28T11:14:50+00:00

Existing sk_drops_add() helper is renamed to sk_drops_skbadd(). Add sk_drops_add() and convert sk_drops_inc() to use it. Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250826125031.1578842-3-edumazet@google.com Signed-off-by: Paolo Abeni