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[ Upstream commit df207de9d9e7a4d92f8567e2c539d9c8c12fd99d ]
Matt Dowling reported a weird UDP memory usage issue.
Under normal operation, the UDP memory usage reported in /proc/net/sockstat
remains close to zero. However, it occasionally spiked to 524,288 pages
and never dropped. Moreover, the value doubled when the application was
terminated. Finally, it caused intermittent packet drops.
We can reproduce the issue with the script below [0]:
1. /proc/net/sockstat reports 0 pages
# cat /proc/net/sockstat | grep UDP:
UDP: inuse 1 mem 0
2. Run the script till the report reaches 524,288
# python3 test.py & sleep 5
# cat /proc/net/sockstat | grep UDP:
UDP: inuse 3 mem 524288 <-- (INT_MAX + 1) >> PAGE_SHIFT
3. Kill the socket and confirm the number never drops
# pkill python3 && sleep 5
# cat /proc/net/sockstat | grep UDP:
UDP: inuse 1 mem 524288
4. (necessary since v6.0) Trigger proto_memory_pcpu_drain()
# python3 test.py & sleep 1 && pkill python3
5. The number doubles
# cat /proc/net/sockstat | grep UDP:
UDP: inuse 1 mem 1048577
The application set INT_MAX to SO_RCVBUF, which triggered an integer
overflow in udp_rmem_release().
When a socket is close()d, udp_destruct_common() purges its receive
queue and sums up skb->truesize in the queue. This total is calculated
and stored in a local unsigned integer variable.
The total size is then passed to udp_rmem_release() to adjust memory
accounting. However, because the function takes a signed integer
argument, the total size can wrap around, causing an overflow.
Then, the released amount is calculated as follows:
1) Add size to sk->sk_forward_alloc.
2) Round down sk->sk_forward_alloc to the nearest lower multiple of
PAGE_SIZE and assign it to amount.
3) Subtract amount from sk->sk_forward_alloc.
4) Pass amount >> PAGE_SHIFT to __sk_mem_reduce_allocated().
When the issue occurred, the total in udp_destruct_common() was 2147484480
(INT_MAX + 833), which was cast to -2147482816 in udp_rmem_release().
At 1) sk->sk_forward_alloc is changed from 3264 to -2147479552, and
2) sets -2147479552 to amount. 3) reverts the wraparound, so we don't
see a warning in inet_sock_destruct(). However, udp_memory_allocated
ends up doubling at 4).
Since commit 3cd3399dd7a8 ("net: implement per-cpu reserves for
memory_allocated"), memory usage no longer doubles immediately after
a socket is close()d because __sk_mem_reduce_allocated() caches the
amount in udp_memory_per_cpu_fw_alloc. However, the next time a UDP
socket receives a packet, the subtraction takes effect, causing UDP
memory usage to double.
This issue makes further memory allocation fail once the socket's
sk->sk_rmem_alloc exceeds net.ipv4.udp_rmem_min, resulting in packet
drops.
To prevent this issue, let's use unsigned int for the calculation and
call sk_forward_alloc_add() only once for the small delta.
Note that first_packet_length() also potentially has the same problem.
[0]:
from socket import *
SO_RCVBUFFORCE = 33
INT_MAX = (2 ** 31) - 1
s = socket(AF_INET, SOCK_DGRAM)
s.bind(('', 0))
s.setsockopt(SOL_SOCKET, SO_RCVBUFFORCE, INT_MAX)
c = socket(AF_INET, SOCK_DGRAM)
c.connect(s.getsockname())
data = b'a' * 100
while True:
c.send(data)
Fixes: f970bd9e3a06 ("udp: implement memory accounting helpers")
Reported-by: Matt Dowling <madowlin@amazon.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250401184501.67377-3-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 5a465a0da13ee9fbd7d3cd0b2893309b0fe4b7e3 ]
__udp_enqueue_schedule_skb() has the following condition:
if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf)
goto drop;
sk->sk_rcvbuf is initialised by net.core.rmem_default and later can
be configured by SO_RCVBUF, which is limited by net.core.rmem_max,
or SO_RCVBUFFORCE.
If we set INT_MAX to sk->sk_rcvbuf, the condition is always false
as sk->sk_rmem_alloc is also signed int.
Then, the size of the incoming skb is added to sk->sk_rmem_alloc
unconditionally.
This results in integer overflow (possibly multiple times) on
sk->sk_rmem_alloc and allows a single socket to have skb up to
net.core.udp_mem[1].
For example, if we set a large value to udp_mem[1] and INT_MAX to
sk->sk_rcvbuf and flood packets to the socket, we can see multiple
overflows:
# cat /proc/net/sockstat | grep UDP:
UDP: inuse 3 mem 7956736 <-- (7956736 << 12) bytes > INT_MAX * 15
^- PAGE_SHIFT
# ss -uam
State Recv-Q ...
UNCONN -1757018048 ... <-- flipping the sign repeatedly
skmem:(r2537949248,rb2147483646,t0,tb212992,f1984,w0,o0,bl0,d0)
Previously, we had a boundary check for INT_MAX, which was removed by
commit 6a1f12dd85a8 ("udp: relax atomic operation on sk->sk_rmem_alloc").
A complete fix would be to revert it and cap the right operand by
INT_MAX:
rmem = atomic_add_return(size, &sk->sk_rmem_alloc);
if (rmem > min(size + (unsigned int)sk->sk_rcvbuf, INT_MAX))
goto uncharge_drop;
but we do not want to add the expensive atomic_add_return() back just
for the corner case.
Casting rmem to unsigned int prevents multiple wraparounds, but we still
allow a single wraparound.
# cat /proc/net/sockstat | grep UDP:
UDP: inuse 3 mem 524288 <-- (INT_MAX + 1) >> 12
# ss -uam
State Recv-Q ...
UNCONN -2147482816 ... <-- INT_MAX + 831 bytes
skmem:(r2147484480,rb2147483646,t0,tb212992,f3264,w0,o0,bl0,d14468947)
So, let's define rmem and rcvbuf as unsigned int and check skb->truesize
only when rcvbuf is large enough to lower the overflow possibility.
Note that we still have a small chance to see overflow if multiple skbs
to the same socket are processed on different core at the same time and
each size does not exceed the limit but the total size does.
Note also that we must ignore skb->truesize for a small buffer as
explained in commit 363dc73acacb ("udp: be less conservative with
sock rmem accounting").
Fixes: 6a1f12dd85a8 ("udp: relax atomic operation on sk->sk_rmem_alloc")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250401184501.67377-2-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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Commit 4094871db1d6 ("udp: only do GSO if # of segs > 1") avoided GSO
for small packets. But the kernel currently dismisses GSO requests only
after checking MTU/PMTU on gso_size. This means any packets, regardless
of their payload sizes, could be dropped when PMTU becomes smaller than
requested gso_size. We encountered this issue in production and it
caused a reliability problem that new QUIC connection cannot be
established before PMTU cache expired, while non GSO sockets still
worked fine at the same time.
Ideally, do not check any GSO related constraints when payload size is
smaller than requested gso_size, and return EMSGSIZE instead of EINVAL
on MTU/PMTU check failure to be more specific on the error cause.
Fixes: 4094871db1d6 ("udp: only do GSO if # of segs > 1")
Signed-off-by: Yan Zhai <yan@cloudflare.com>
Suggested-by: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Cross-merge networking fixes after downstream PR (net-6.13-rc8).
Conflicts:
drivers/net/ethernet/realtek/r8169_main.c
1f691a1fc4be ("r8169: remove redundant hwmon support")
152d00a91396 ("r8169: simplify setting hwmon attribute visibility")
https://lore.kernel.org/20250115122152.760b4e8d@canb.auug.org.au
Adjacent changes:
drivers/net/ethernet/broadcom/bnxt/bnxt.c
152f4da05aee ("bnxt_en: add support for rx-copybreak ethtool command")
f0aa6a37a3db ("eth: bnxt: always recalculate features after XDP clearing, fix null-deref")
drivers/net/ethernet/intel/ice/ice_type.h
50327223a8bb ("ice: add lock to protect low latency interface")
dc26548d729e ("ice: Fix quad registers read on E825")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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As discussed in [0], rehash4 could be missed in udp_lib_rehash() when
udp hash4 changes while hash2 doesn't change. This patch fixes this by
moving rehash4 codes out of rehash2 checking, and then rehash2 and
rehash4 are done separately.
By doing this, we no longer need to call rehash4 explicitly in
udp_lib_hash4(), as the rehash callback in __ip4_datagram_connect takes
it. Thus, now udp_lib_hash4() returns directly if the sk is already
hashed.
Note that uhash4 may fail to work under consecutive connect(<dst
address>) calls because rehash() is not called with every connect(). To
overcome this, connect(<AF_UNSPEC>) needs to be called after the next
connect to a new destination.
[0]
https://lore.kernel.org/all/4761e466ab9f7542c68cdc95f248987d127044d2.1733499715.git.pabeni@redhat.com/
Fixes: 78c91ae2c6de ("ipv4/udp: Add 4-tuple hash for connected socket")
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Philo Lu <lulie@linux.alibaba.com>
Link: https://patch.msgid.link/20250110010810.107145-1-lulie@linux.alibaba.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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If a UDP socket changes its local address while it's receiving
datagrams, as a result of connect(), there is a period during which
a lookup operation might fail to find it, after the address is changed
but before the secondary hash (port and address) and the four-tuple
hash (local and remote ports and addresses) are updated.
Secondary hash chains were introduced by commit 30fff9231fad ("udp:
bind() optimisation") and, as a result, a rehash operation became
needed to make a bound socket reachable again after a connect().
This operation was introduced by commit 719f835853a9 ("udp: add
rehash on connect()") which isn't however a complete fix: the
socket will be found once the rehashing completes, but not while
it's pending.
This is noticeable with a socat(1) server in UDP4-LISTEN mode, and a
client sending datagrams to it. After the server receives the first
datagram (cf. _xioopen_ipdgram_listen()), it issues a connect() to
the address of the sender, in order to set up a directed flow.
Now, if the client, running on a different CPU thread, happens to
send a (subsequent) datagram while the server's socket changes its
address, but is not rehashed yet, this will result in a failed
lookup and a port unreachable error delivered to the client, as
apparent from the following reproducer:
LEN=$(($(cat /proc/sys/net/core/wmem_default) / 4))
dd if=/dev/urandom bs=1 count=${LEN} of=tmp.in
while :; do
taskset -c 1 socat UDP4-LISTEN:1337,null-eof OPEN:tmp.out,create,trunc &
sleep 0.1 || sleep 1
taskset -c 2 socat OPEN:tmp.in UDP4:localhost:1337,shut-null
wait
done
where the client will eventually get ECONNREFUSED on a write()
(typically the second or third one of a given iteration):
2024/11/13 21:28:23 socat[46901] E write(6, 0x556db2e3c000, 8192): Connection refused
This issue was first observed as a seldom failure in Podman's tests
checking UDP functionality while using pasta(1) to connect the
container's network namespace, which leads us to a reproducer with
the lookup error resulting in an ICMP packet on a tap device:
LOCAL_ADDR="$(ip -j -4 addr show|jq -rM '.[] | .addr_info[0] | select(.scope == "global").local')"
while :; do
./pasta --config-net -p pasta.pcap -u 1337 socat UDP4-LISTEN:1337,null-eof OPEN:tmp.out,create,trunc &
sleep 0.2 || sleep 1
socat OPEN:tmp.in UDP4:${LOCAL_ADDR}:1337,shut-null
wait
cmp tmp.in tmp.out
done
Once this fails:
tmp.in tmp.out differ: char 8193, line 29
we can finally have a look at what's going on:
$ tshark -r pasta.pcap
1 0.000000 :: ? ff02::16 ICMPv6 110 Multicast Listener Report Message v2
2 0.168690 88.198.0.161 ? 88.198.0.164 UDP 8234 60260 ? 1337 Len=8192
3 0.168767 88.198.0.161 ? 88.198.0.164 UDP 8234 60260 ? 1337 Len=8192
4 0.168806 88.198.0.161 ? 88.198.0.164 UDP 8234 60260 ? 1337 Len=8192
5 0.168827 c6:47:05:8d:dc:04 ? Broadcast ARP 42 Who has 88.198.0.161? Tell 88.198.0.164
6 0.168851 9a:55:9a:55:9a:55 ? c6:47:05:8d:dc:04 ARP 42 88.198.0.161 is at 9a:55:9a:55:9a:55
7 0.168875 88.198.0.161 ? 88.198.0.164 UDP 8234 60260 ? 1337 Len=8192
8 0.168896 88.198.0.164 ? 88.198.0.161 ICMP 590 Destination unreachable (Port unreachable)
9 0.168926 88.198.0.161 ? 88.198.0.164 UDP 8234 60260 ? 1337 Len=8192
10 0.168959 88.198.0.161 ? 88.198.0.164 UDP 8234 60260 ? 1337 Len=8192
11 0.168989 88.198.0.161 ? 88.198.0.164 UDP 4138 60260 ? 1337 Len=4096
12 0.169010 88.198.0.161 ? 88.198.0.164 UDP 42 60260 ? 1337 Len=0
On the third datagram received, the network namespace of the container
initiates an ARP lookup to deliver the ICMP message.
In another variant of this reproducer, starting the client with:
strace -f pasta --config-net -u 1337 socat UDP4-LISTEN:1337,null-eof OPEN:tmp.out,create,trunc 2>strace.log &
and connecting to the socat server using a loopback address:
socat OPEN:tmp.in UDP4:localhost:1337,shut-null
we can more clearly observe a sendmmsg() call failing after the
first datagram is delivered:
[pid 278012] connect(173, 0x7fff96c95fc0, 16) = 0
[...]
[pid 278012] recvmmsg(173, 0x7fff96c96020, 1024, MSG_DONTWAIT, NULL) = -1 EAGAIN (Resource temporarily unavailable)
[pid 278012] sendmmsg(173, 0x561c5ad0a720, 1, MSG_NOSIGNAL) = 1
[...]
[pid 278012] sendmmsg(173, 0x561c5ad0a720, 1, MSG_NOSIGNAL) = -1 ECONNREFUSED (Connection refused)
and, somewhat confusingly, after a connect() on the same socket
succeeded.
Until commit 4cdeeee9252a ("net: udp: prefer listeners bound to an
address"), the race between receive address change and lookup didn't
actually cause visible issues, because, once the lookup based on the
secondary hash chain failed, we would still attempt a lookup based on
the primary hash (destination port only), and find the socket with the
outdated secondary hash.
That change, however, dropped port-only lookups altogether, as side
effect, making the race visible.
To fix this, while avoiding the need to make address changes and
rehash atomic against lookups, reintroduce primary hash lookups as
fallback, if lookups based on four-tuple and secondary hashes fail.
To this end, introduce a simplified lookup implementation, which
doesn't take care of SO_REUSEPORT groups: if we have one, there are
multiple sockets that would match the four-tuple or secondary hash,
meaning that we can't run into this race at all.
v2:
- instead of synchronising lookup operations against address change
plus rehash, reintroduce a simplified version of the original
primary hash lookup as fallback
v1:
- fix build with CONFIG_IPV6=n: add ifdef around sk_v6_rcv_saddr
usage (Kuniyuki Iwashima)
- directly use sk_rcv_saddr for IPv4 receive addresses instead of
fetching inet_rcv_saddr (Kuniyuki Iwashima)
- move inet_update_saddr() to inet_hashtables.h and use that
to set IPv4/IPv6 addresses as suitable (Kuniyuki Iwashima)
- rebase onto net-next, update commit message accordingly
Reported-by: Ed Santiago <santiago@redhat.com>
Link: https://github.com/containers/podman/issues/24147
Analysed-by: David Gibson <david@gibson.dropbear.id.au>
Fixes: 30fff9231fad ("udp: bind() optimisation")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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This reverts commit 612b1c0dec5bc7367f90fc508448b8d0d7c05414. On a
scenario with multiple threads blocking on a recvfrom(), we need to call
sock_def_readable() on every __udp_enqueue_schedule_skb() otherwise the
threads won't be woken up as __skb_wait_for_more_packets() is using
prepare_to_wait_exclusive().
Link: https://bugzilla.redhat.com/2308477
Fixes: 612b1c0dec5b ("udp: avoid calling sock_def_readable() if possible")
Signed-off-by: Fernando Fernandez Mancera <ffmancera@riseup.net>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20241202155620.1719-1-ffmancera@riseup.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Implement ipv6 udp hash4 like that in ipv4. The major difference is that
the hash value should be calculated with udp6_ehashfn(). Besides,
ipv4-mapped ipv6 address is handled before hash() and rehash(). Export
udp_ehashfn because now we use it in udpv6 rehash.
Core procedures of hash/unhash/rehash are same as ipv4, and udpv4 and
udpv6 share the same udptable, so some functions in ipv4 hash4 can also
be shared.
Co-developed-by: Cambda Zhu <cambda@linux.alibaba.com>
Signed-off-by: Cambda Zhu <cambda@linux.alibaba.com>
Co-developed-by: Fred Chen <fred.cc@alibaba-inc.com>
Signed-off-by: Fred Chen <fred.cc@alibaba-inc.com>
Co-developed-by: Yubing Qiu <yubing.qiuyubing@alibaba-inc.com>
Signed-off-by: Yubing Qiu <yubing.qiuyubing@alibaba-inc.com>
Signed-off-by: Philo Lu <lulie@linux.alibaba.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Currently, the udp_table has two hash table, the port hash and portaddr
hash. Usually for UDP servers, all sockets have the same local port and
addr, so they are all on the same hash slot within a reuseport group.
In some applications, UDP servers use connect() to manage clients. In
particular, when firstly receiving from an unseen 4 tuple, a new socket
is created and connect()ed to the remote addr:port, and then the fd is
used exclusively by the client.
Once there are connected sks in a reuseport group, udp has to score all
sks in the same hash2 slot to find the best match. This could be
inefficient with a large number of connections, resulting in high
softirq overhead.
To solve the problem, this patch implement 4-tuple hash for connected
udp sockets. During connect(), hash4 slot is updated, as well as a
corresponding counter, hash4_cnt, in hslot2. In __udp4_lib_lookup(),
hslot4 will be searched firstly if the counter is non-zero. Otherwise,
hslot2 is used like before. Note that only connected sockets enter this
hash4 path, while un-connected ones are not affected.
hlist_nulls is used for hash4, because we probably move to another hslot
wrongly when lookup with concurrent rehash. Then we check nulls at the
list end to see if we should restart lookup. Because udp does not use
SLAB_TYPESAFE_BY_RCU, we don't need to touch sk_refcnt when lookup.
Stress test results (with 1 cpu fully used) are shown below, in pps:
(1) _un-connected_ socket as server
[a] w/o hash4: 1,825176
[b] w/ hash4: 1,831750 (+0.36%)
(2) 500 _connected_ sockets as server
[c] w/o hash4: 290860 (only 16% of [a])
[d] w/ hash4: 1,889658 (+3.1% compared with [b])
With hash4, compute_score is skipped when lookup, so [d] is slightly
better than [b].
Co-developed-by: Cambda Zhu <cambda@linux.alibaba.com>
Signed-off-by: Cambda Zhu <cambda@linux.alibaba.com>
Co-developed-by: Fred Chen <fred.cc@alibaba-inc.com>
Signed-off-by: Fred Chen <fred.cc@alibaba-inc.com>
Co-developed-by: Yubing Qiu <yubing.qiuyubing@alibaba-inc.com>
Signed-off-by: Yubing Qiu <yubing.qiuyubing@alibaba-inc.com>
Signed-off-by: Philo Lu <lulie@linux.alibaba.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Add a new hash list, hash4, in udp table. It will be used to implement
4-tuple hash for connected udp sockets. This patch adds the hlist to
table, and implements helpers and the initialization. 4-tuple hash is
implemented in the following patch.
hash4 uses hlist_nulls to avoid moving wrongly onto another hlist due to
concurrent rehash, because rehash() can happen with lookup().
Co-developed-by: Cambda Zhu <cambda@linux.alibaba.com>
Signed-off-by: Cambda Zhu <cambda@linux.alibaba.com>
Co-developed-by: Fred Chen <fred.cc@alibaba-inc.com>
Signed-off-by: Fred Chen <fred.cc@alibaba-inc.com>
Co-developed-by: Yubing Qiu <yubing.qiuyubing@alibaba-inc.com>
Signed-off-by: Yubing Qiu <yubing.qiuyubing@alibaba-inc.com>
Signed-off-by: Philo Lu <lulie@linux.alibaba.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Preparing for udp 4-tuple hash (uhash4 for short).
To implement uhash4 without cache line missing when lookup, hslot2 is
used to record the number of hashed sockets in hslot4. Thus adding a new
struct udp_hslot_main with field hash4_cnt, which is used by hash2. The
new struct is used to avoid doubling the size of udp_hslot.
Before uhash4 lookup, firstly checking hash4_cnt to see if there are
hashed sks in hslot4. Because hslot2 is always used in lookup, there is
no cache line miss.
Related helpers are updated, and use the helpers as possible.
uhash4 is implemented in following patches.
Signed-off-by: Philo Lu <lulie@linux.alibaba.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Cross-merge networking fixes after downstream PR (net-6.12-rc4).
Conflicts:
107a034d5c1e ("net/mlx5: qos: Store rate groups in a qos domain")
1da9cfd6c41c ("net/mlx5: Unregister notifier on eswitch init failure")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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If:
1) the user requested USO, but
2) there is not enough payload for GSO to kick in, and
3) the egress device doesn't offer checksum offload, then
we want to compute the L4 checksum in software early on.
In the case when we are not taking the GSO path, but it has been requested,
the software checksum fallback in skb_segment doesn't get a chance to
compute the full checksum, if the egress device can't do it. As a result we
end up sending UDP datagrams with only a partial checksum filled in, which
the peer will discard.
Fixes: 10154dbded6d ("udp: Allow GSO transmit from devices with no checksum offload")
Reported-by: Ivan Babrou <ivan@cloudflare.com>
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20241011-uso-swcsum-fixup-v2-1-6e1ddc199af9@cloudflare.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Pass a dscp_t variable to ip_mc_validate_source(), instead of a plain
u8, to prevent accidental setting of ECN bits in ->flowi4_tos.
Callers of ip_mc_validate_source() to consider are:
* ip_route_input_mc() which already has a dscp_t variable to pass as
parameter. We just need to remove the inet_dscp_to_dsfield()
conversion.
* udp_v4_early_demux() which gets the DSCP directly from the IPv4
header and can simply use the ip4h_dscp() helper.
Also, stop including net/inet_dscp.h in udp.c as we don't use any of
its declarations anymore.
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Tested-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/c91b2cca04718b7ee6cf5b9c1d5b40507d65a8d4.1728302212.git.gnault@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Unmask the upper DSCP bits when performing source validation for
multicast packets during early demux. In the future, this will allow us
to perform the FIB lookup which is performed as part of source
validation according to the full DSCP value.
No functional changes intended since the upper DSCP bits are masked when
comparing against the TOS selectors in FIB rules and routes.
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Acked-by: Florian Westphal <fw@strlen.de>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20240821125251.1571445-12-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Following helpers do not touch their 'struct net' argument.
- udp_sk_bound_dev_eq()
- udp4_lib_lookup()
- __udp4_lib_lookup()
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20240802134029.3748005-4-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Cross-merge networking fixes after downstream PR.
Conflicts:
net/sched/act_ct.c
26488172b029 ("net/sched: Fix UAF when resolving a clash")
3abbd7ed8b76 ("act_ct: prepare for stolen verdict coming from conntrack and nat engine")
No adjacent changes.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
syzkaller triggered the warning [0] in udp_v4_early_demux().
In udp_v[46]_early_demux() and sk_lookup(), we do not touch the refcount
of the looked-up sk and use sock_pfree() as skb->destructor, so we check
SOCK_RCU_FREE to ensure that the sk is safe to access during the RCU grace
period.
Currently, SOCK_RCU_FREE is flagged for a bound socket after being put
into the hash table. Moreover, the SOCK_RCU_FREE check is done too early
in udp_v[46]_early_demux() and sk_lookup(), so there could be a small race
window:
CPU1 CPU2
---- ----
udp_v4_early_demux() udp_lib_get_port()
| |- hlist_add_head_rcu()
|- sk = __udp4_lib_demux_lookup() |
|- DEBUG_NET_WARN_ON_ONCE(sk_is_refcounted(sk));
`- sock_set_flag(sk, SOCK_RCU_FREE)
We had the same bug in TCP and fixed it in commit 871019b22d1b ("net:
set SOCK_RCU_FREE before inserting socket into hashtable").
Let's apply the same fix for UDP.
[0]:
WARNING: CPU: 0 PID: 11198 at net/ipv4/udp.c:2599 udp_v4_early_demux+0x481/0xb70 net/ipv4/udp.c:2599
Modules linked in:
CPU: 0 PID: 11198 Comm: syz-executor.1 Not tainted 6.9.0-g93bda33046e7 #13
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
RIP: 0010:udp_v4_early_demux+0x481/0xb70 net/ipv4/udp.c:2599
Code: c5 7a 15 fe bb 01 00 00 00 44 89 e9 31 ff d3 e3 81 e3 bf ef ff ff 89 de e8 2c 74 15 fe 85 db 0f 85 02 06 00 00 e8 9f 7a 15 fe <0f> 0b e8 98 7a 15 fe 49 8d 7e 60 e8 4f 39 2f fe 49 c7 46 60 20 52
RSP: 0018:ffffc9000ce3fa58 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff8318c92c
RDX: ffff888036ccde00 RSI: ffffffff8318c2f1 RDI: 0000000000000001
RBP: ffff88805a2dd6e0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0001ffffffffffff R12: ffff88805a2dd680
R13: 0000000000000007 R14: ffff88800923f900 R15: ffff88805456004e
FS: 00007fc449127640(0000) GS:ffff88807dc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc449126e38 CR3: 000000003de4b002 CR4: 0000000000770ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
PKRU: 55555554
Call Trace:
<TASK>
ip_rcv_finish_core.constprop.0+0xbdd/0xd20 net/ipv4/ip_input.c:349
ip_rcv_finish+0xda/0x150 net/ipv4/ip_input.c:447
NF_HOOK include/linux/netfilter.h:314 [inline]
NF_HOOK include/linux/netfilter.h:308 [inline]
ip_rcv+0x16c/0x180 net/ipv4/ip_input.c:569
__netif_receive_skb_one_core+0xb3/0xe0 net/core/dev.c:5624
__netif_receive_skb+0x21/0xd0 net/core/dev.c:5738
netif_receive_skb_internal net/core/dev.c:5824 [inline]
netif_receive_skb+0x271/0x300 net/core/dev.c:5884
tun_rx_batched drivers/net/tun.c:1549 [inline]
tun_get_user+0x24db/0x2c50 drivers/net/tun.c:2002
tun_chr_write_iter+0x107/0x1a0 drivers/net/tun.c:2048
new_sync_write fs/read_write.c:497 [inline]
vfs_write+0x76f/0x8d0 fs/read_write.c:590
ksys_write+0xbf/0x190 fs/read_write.c:643
__do_sys_write fs/read_write.c:655 [inline]
__se_sys_write fs/read_write.c:652 [inline]
__x64_sys_write+0x41/0x50 fs/read_write.c:652
x64_sys_call+0xe66/0x1990 arch/x86/include/generated/asm/syscalls_64.h:2
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x4b/0x110 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x4b/0x53
RIP: 0033:0x7fc44a68bc1f
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 e9 cf f5 ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 3c d0 f5 ff 48
RSP: 002b:00007fc449126c90 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00000000004bc050 RCX: 00007fc44a68bc1f
RDX: 0000000000000032 RSI: 00000000200000c0 RDI: 00000000000000c8
RBP: 00000000004bc050 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000032 R11: 0000000000000293 R12: 0000000000000000
R13: 000000000000000b R14: 00007fc44a5ec530 R15: 0000000000000000
</TASK>
Fixes: 6acc9b432e67 ("bpf: Add helper to retrieve socket in BPF")
Reported-by: syzkaller <syzkaller@googlegroups.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20240709191356.24010-1-kuniyu@amazon.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
|
|
Today sending a UDP GSO packet from a TUN device results in an EIO error:
import fcntl, os, struct
from socket import *
TUNSETIFF = 0x400454CA
IFF_TUN = 0x0001
IFF_NO_PI = 0x1000
UDP_SEGMENT = 103
tun_fd = os.open("/dev/net/tun", os.O_RDWR)
ifr = struct.pack("16sH", b"tun0", IFF_TUN | IFF_NO_PI)
fcntl.ioctl(tun_fd, TUNSETIFF, ifr)
os.system("ip addr add 192.0.2.1/24 dev tun0")
os.system("ip link set dev tun0 up")
s = socket(AF_INET, SOCK_DGRAM)
s.setsockopt(SOL_UDP, UDP_SEGMENT, 1200)
s.sendto(b"x" * 3000, ("192.0.2.2", 9)) # EIO
This is due to a check in the udp stack if the egress device offers
checksum offload. While TUN/TAP devices, by default, don't advertise this
capability because it requires support from the TUN/TAP reader.
However, the GSO stack has a software fallback for checksum calculation,
which we can use. This way we don't force UDP_SEGMENT users to handle the
EIO error and implement a segmentation fallback.
Lift the restriction so that UDP_SEGMENT can be used with any egress
device. We also need to adjust the UDP GSO code to match the GSO stack
expectation about ip_summed field, as set in commit 8d63bee643f1 ("net:
avoid skb_warn_bad_offload false positives on UFO"). Otherwise we will hit
the bad offload check.
Users should, however, expect a potential performance impact when
batch-sending packets with UDP_SEGMENT without checksum offload on the
egress device. In such case the packet payload is read twice: first during
the sendmsg syscall when copying data from user memory, and then in the GSO
stack for checksum computation. This double memory read can be less
efficient than a regular sendmsg where the checksum is calculated during
the initial data copy from user memory.
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20240626-linux-udpgso-v2-1-422dfcbd6b48@cloudflare.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Replace kfree_skb_reason with sk_skb_reason_drop and pass the receiving
socket to the tracepoint.
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/r/202406011751.NpVN0sSk-lkp@intel.com/
Signed-off-by: Yan Zhai <yan@cloudflare.com>
Acked-by: Jesper Dangaard Brouer <hawk@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Toke mentioned unrcu_pointer() existence, allowing
to remove some of the ugly casts we have when using
xchg() for rcu protected pointers.
Also make inet_rcv_compat const.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Toke Høiland-Jørgensen <toke@redhat.com>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/r/20240604111603.45871-1-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next
Steffen Klassert says:
====================
pull request (net-next): ipsec-next 2024-05-03
1) Remove Obsolete UDP_ENCAP_ESPINUDP_NON_IKE Support.
This was defined by an early version of an IETF draft
that did not make it to a standard.
2) Introduce direction attribute for xfrm states.
xfrm states have a direction, a stsate can be used
either for input or output packet processing.
Add a direction to xfrm states to make it clear
for what a xfrm state is used.
* tag 'ipsec-next-2024-05-03' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next:
xfrm: Restrict SA direction attribute to specific netlink message types
xfrm: Add dir validation to "in" data path lookup
xfrm: Add dir validation to "out" data path lookup
xfrm: Add Direction to the SA in or out
udpencap: Remove Obsolete UDP_ENCAP_ESPINUDP_NON_IKE Support
====================
Link: https://lore.kernel.org/r/20240503082732.2835810-1-steffen.klassert@secunet.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Cross-merge networking fixes after downstream PR.
Conflicts:
include/linux/filter.h
kernel/bpf/core.c
66e13b615a0c ("bpf: verifier: prevent userspace memory access")
d503a04f8bc0 ("bpf: Add support for certain atomics in bpf_arena to x86 JIT")
https://lore.kernel.org/all/20240429114939.210328b0@canb.auug.org.au/
No adjacent changes.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
{inner_}network_offset to napi_gro_cb
Commits a602456 ("udp: Add GRO functions to UDP socket") and 57c67ff ("udp:
additional GRO support") introduce incorrect usage of {ip,ipv6}_hdr in the
complete phase of gro. The functions always return skb->network_header,
which in the case of encapsulated packets at the gro complete phase, is
always set to the innermost L3 of the packet. That means that calling
{ip,ipv6}_hdr for skbs which completed the GRO receive phase (both in
gro_list and *_gro_complete) when parsing an encapsulated packet's _outer_
L3/L4 may return an unexpected value.
This incorrect usage leads to a bug in GRO's UDP socket lookup.
udp{4,6}_lib_lookup_skb functions use ip_hdr/ipv6_hdr respectively. These
*_hdr functions return network_header which will point to the innermost L3,
resulting in the wrong offset being used in __udp{4,6}_lib_lookup with
encapsulated packets.
This patch adds network_offset and inner_network_offset to napi_gro_cb, and
makes sure both are set correctly.
To fix the issue, network_offsets union is used inside napi_gro_cb, in
which both the outer and the inner network offsets are saved.
Reproduction example:
Endpoint configuration example (fou + local address bind)
# ip fou add port 6666 ipproto 4
# ip link add name tun1 type ipip remote 2.2.2.1 local 2.2.2.2 encap fou encap-dport 5555 encap-sport 6666 mode ipip
# ip link set tun1 up
# ip a add 1.1.1.2/24 dev tun1
Netperf TCP_STREAM result on net-next before patch is applied:
net-next main, GRO enabled:
$ netperf -H 1.1.1.2 -t TCP_STREAM -l 5
Recv Send Send
Socket Socket Message Elapsed
Size Size Size Time Throughput
bytes bytes bytes secs. 10^6bits/sec
131072 16384 16384 5.28 2.37
net-next main, GRO disabled:
$ netperf -H 1.1.1.2 -t TCP_STREAM -l 5
Recv Send Send
Socket Socket Message Elapsed
Size Size Size Time Throughput
bytes bytes bytes secs. 10^6bits/sec
131072 16384 16384 5.01 2745.06
patch applied, GRO enabled:
$ netperf -H 1.1.1.2 -t TCP_STREAM -l 5
Recv Send Send
Socket Socket Message Elapsed
Size Size Size Time Throughput
bytes bytes bytes secs. 10^6bits/sec
131072 16384 16384 5.01 2877.38
Fixes: a6024562ffd7 ("udp: Add GRO functions to UDP socket")
Signed-off-by: Richard Gobert <richardbgobert@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
|
|
I added dst_rt6_info() in commit
e8dfd42c17fa ("ipv6: introduce dst_rt6_info() helper")
This patch does a similar change for IPv4.
Instead of (struct rtable *)dst casts, we can use :
#define dst_rtable(_ptr) \
container_of_const(_ptr, struct rtable, dst)
Patch is smaller than IPv6 one, because IPv4 has skb_rtable() helper.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Link: https://lore.kernel.org/r/20240429133009.1227754-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Cross-merge networking fixes after downstream PR.
Conflicts:
drivers/net/ethernet/ti/icssg/icssg_prueth.c
net/mac80211/chan.c
89884459a0b9 ("wifi: mac80211: fix idle calculation with multi-link")
87f5500285fb ("wifi: mac80211: simplify ieee80211_assign_link_chanctx()")
https://lore.kernel.org/all/20240422105623.7b1fbda2@canb.auug.org.au/
net/unix/garbage.c
1971d13ffa84 ("af_unix: Suppress false-positive lockdep splat for spin_lock() in __unix_gc().")
4090fa373f0e ("af_unix: Replace garbage collection algorithm.")
drivers/net/ethernet/ti/icssg/icssg_prueth.c
drivers/net/ethernet/ti/icssg/icssg_common.c
4dcd0e83ea1d ("net: ti: icssg-prueth: Fix signedness bug in prueth_init_rx_chns()")
e2dc7bfd677f ("net: ti: icssg-prueth: Move common functions into a separate file")
No adjacent changes.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
If "udp_cmsg_send()" returned 0 (i.e. only UDP cmsg),
"connected" should not be set to 0. Otherwise it stops
the connected socket from using the cached route.
Fixes: 2e8de8576343 ("udp: add gso segment cmsg")
Signed-off-by: Yick Xie <yick.xie@gmail.com>
Cc: stable@vger.kernel.org
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/20240418170610.867084-1-yick.xie@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
The UDP_ENCAP_ESPINUDP_NON_IKE mode, introduced into the Linux kernel
in 2004 [2], has remained inactive and obsolete for an extended period.
This mode was originally defined in an early version of an IETF draft
[1] from 2001. By the time it was integrated into the kernel in 2004 [2],
it had already been replaced by UDP_ENCAP_ESPINUDP [3] in later
versions of draft-ietf-ipsec-udp-encaps, particularly in version 06.
Over time, UDP_ENCAP_ESPINUDP_NON_IKE has lost its relevance, with no
known use cases.
With this commit, we remove support for UDP_ENCAP_ESPINUDP_NON_IKE,
simplifying the codebase and eliminating unnecessary complexity.
Kernel will return an error -ENOPROTOOPT if the userspace tries to set
this option.
References:
[1] https://datatracker.ietf.org/doc/html/draft-ietf-ipsec-udp-encaps-00.txt
[2] Commit that added UDP_ENCAP_ESPINUDP_NON_IKE to the Linux historic
repository.
Author: Andreas Gruenbacher <agruen@suse.de>
Date: Fri Apr 9 01:47:47 2004 -0700
[IPSEC]: Support draft-ietf-ipsec-udp-encaps-00/01, some ipec impls need it.
[3] Commit that added UDP_ENCAP_ESPINUDP to the Linux historic
repository.
Author: Derek Atkins <derek@ihtfp.com>
Date: Wed Apr 2 13:21:02 2003 -0800
[IPSEC]: Implement UDP Encapsulation framework.
Signed-off-by: Antony Antony <antony.antony@secunet.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
|
|
We've observed a 7-12% performance regression in iperf3 UDP ipv4 and
ipv6 tests with multiple sockets on Zen3 cpus, which we traced back to
commit f0ea27e7bfe1 ("udp: re-score reuseport groups when connected
sockets are present"). The failing tests were those that would spawn
UDP sockets per-cpu on systems that have a high number of cpus.
Unsurprisingly, it is not caused by the extra re-scoring of the reused
socket, but due to the compiler no longer inlining compute_score, once
it has the extra call site in udp4_lib_lookup2. This is augmented by
the "Safe RET" mitigation for SRSO, needed in our Zen3 cpus.
We could just explicitly inline it, but compute_score() is quite a large
function, around 300b. Inlining in two sites would almost double
udp4_lib_lookup2, which is a silly thing to do just to workaround a
mitigation. Instead, this patch shuffles the code a bit to avoid the
multiple calls to compute_score. Since it is a static function used in
one spot, the compiler can safely fold it in, as it did before, without
increasing the text size.
With this patch applied I ran my original iperf3 testcases. The failing
cases all looked like this (ipv4):
iperf3 -c 127.0.0.1 --udp -4 -f K -b $R -l 8920 -t 30 -i 5 -P 64 -O 2
where $R is either 1G/10G/0 (max, unlimited). I ran 3 times each.
baseline is v6.9-rc3. harmean == harmonic mean; CV == coefficient of
variation.
ipv4:
1G 10G MAX
HARMEAN (CV) HARMEAN (CV) HARMEAN (CV)
baseline 1743852.66(0.0208) 1725933.02(0.0167) 1705203.78(0.0386)
patched 1968727.61(0.0035) 1962283.22(0.0195) 1923853.50(0.0256)
ipv6:
1G 10G MAX
HARMEAN (CV) HARMEAN (CV) HARMEAN (CV)
baseline 1729020.03(0.0028) 1691704.49(0.0243) 1692251.34(0.0083)
patched 1900422.19(0.0067) 1900968.01(0.0067) 1568532.72(0.1519)
This restores the performance we had before the change above with this
benchmark. We obviously don't expect any real impact when mitigations
are disabled, but just to be sure it also doesn't regresses:
mitigations=off ipv4:
1G 10G MAX
HARMEAN (CV) HARMEAN (CV) HARMEAN (CV)
baseline 3230279.97(0.0066) 3229320.91(0.0060) 2605693.19(0.0697)
patched 3242802.36(0.0073) 3239310.71(0.0035) 2502427.19(0.0882)
Cc: Lorenz Bauer <lmb@isovalent.com>
Fixes: f0ea27e7bfe1 ("udp: re-score reuseport groups when connected sockets are present")
Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Cross-merge networking fixes after downstream PR.
Conflicts:
net/ipv4/ip_gre.c
17af420545a7 ("erspan: make sure erspan_base_hdr is present in skb->head")
5832c4a77d69 ("ip_tunnel: convert __be16 tunnel flags to bitmaps")
https://lore.kernel.org/all/20240402103253.3b54a1cf@canb.auug.org.au/
Adjacent changes:
net/ipv6/ip6_fib.c
d21d40605bca ("ipv6: Fix infinite recursion in fib6_dump_done().")
5fc68320c1fb ("ipv6: remove RTNL protection from inet6_dump_fib()")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
While looking at UDP receive performance, I saw sk_wake_async()
was no longer inlined.
This matters at least on AMD Zen1-4 platforms (see SRSO)
This might be because rcu_read_lock() and rcu_read_unlock()
are no longer nops in recent kernels ?
Add sk_wake_async_rcu() variant, which must be called from
contexts already holding rcu lock.
As SOCK_FASYNC is deprecated in modern days, use unlikely()
to give a hint to the compiler.
sk_wake_async_rcu() is properly inlined from
__udp_enqueue_schedule_skb() and sock_def_readable().
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240328144032.1864988-5-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
sock_def_readable() is quite expensive (particularly
when ep_poll_callback() is in the picture).
We must call sk->sk_data_ready() when :
- receive queue was empty, or
- SO_PEEK_OFF is enabled on the socket, or
- sk->sk_data_ready is not sock_def_readable.
We still need to call sk_wake_async().
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/20240328144032.1864988-4-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
atomic_add_return() is more expensive than atomic_add()
and seems overkill in UDP rx fast path.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240328144032.1864988-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
sk->sk_rcvbuf is read locklessly twice, while other threads
could change its value.
Use a READ |
