linux.git/net/core/gro.c, branch v6.2 Linux kernel source tree skb: Do mix page pool and page referenced frags in GRO 2023-01-28T07:21:27+00:00 Alexander Duyck alexanderduyck@fb.com 2023-01-26T19:06:59+00:00 7d2c89b325874a35564db5630a459966afab04cc GSO should not merge page pool recycled frames with standard reference counted frames. Traditionally this didn't occur, at least not often. However as we start looking at adding support for wireless adapters there becomes the potential to mix the two due to A-MSDU repartitioning frames in the receive path. There are possibly other places where this may have occurred however I suspect they must be few and far between as we have not seen this issue until now. Fixes: 53e0961da1c7 ("page_pool: add frag page recycling support in page pool") Reported-by: Felix Fietkau <nbd@nbd.name> Signed-off-by: Alexander Duyck <alexanderduyck@fb.com> Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/167475990764.1934330.11960904198087757911.stgit@localhost.localdomain Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
GSO should not merge page pool recycled frames with standard reference
counted frames. Traditionally this didn't occur, at least not often.
However as we start looking at adding support for wireless adapters there
becomes the potential to mix the two due to A-MSDU repartitioning frames in
the receive path. There are possibly other places where this may have
occurred however I suspect they must be few and far between as we have not
seen this issue until now.

Fixes: 53e0961da1c7 ("page_pool: add frag page recycling support in page pool")
Reported-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Alexander Duyck <alexanderduyck@fb.com>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/167475990764.1934330.11960904198087757911.stgit@localhost.localdomain
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
gro: take care of DODGY packets 2023-01-09T07:37:07+00:00 Eric Dumazet edumazet@google.com 2023-01-06T14:25:23+00:00 7871f54e3deed68a27111dda162c4fe9b9c65f8f Jaroslav reported a recent throughput regression with virtio_net caused by blamed commit. It is unclear if DODGY GSO packets coming from user space can be accepted by GRO engine in the future with minimal changes, and if there is any expected gain from it. In the meantime, make sure to detect and flush DODGY packets. Fixes: 5eddb24901ee ("gro: add support of (hw)gro packets to gro stack") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-and-bisected-by: Jaroslav Pulchart <jaroslav.pulchart@gooddata.com> Cc: Coco Li <lixiaoyan@google.com> Cc: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Jaroslav reported a recent throughput regression with virtio_net
caused by blamed commit.

It is unclear if DODGY GSO packets coming from user space
can be accepted by GRO engine in the future with minimal
changes, and if there is any expected gain from it.

In the meantime, make sure to detect and flush DODGY packets.

Fixes: 5eddb24901ee ("gro: add support of (hw)gro packets to gro stack")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-and-bisected-by: Jaroslav Pulchart <jaroslav.pulchart@gooddata.com>
Cc: Coco Li <lixiaoyan@google.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: gro: no longer use skb_vlan_tag_present() 2022-11-12T02:18:05+00:00 Eric Dumazet edumazet@google.com 2022-11-09T09:57:59+00:00 be3ed48683f0d7ed808783fd7d919459b58b5b6b We can remove a conditional test in gro_list_prepare() by comparing vlan_all fields of the two skbs. Notes: While comparing the vlan_proto is not strictly needed, because part of the following compare_ether_header() call, using 32bit word is actually faster than using 16bit values. napi_reuse_skb() makes sure to clear skb->vlan_all, as it already calls __vlan_hwaccel_clear_tag() Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Martin KaFai Lau <martin.lau@kernel.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
We can remove a conditional test in gro_list_prepare()
by comparing vlan_all fields of the two skbs.

Notes:

While comparing the vlan_proto is not strictly needed,
because part of the following compare_ether_header() call,
using 32bit word is actually faster than using 16bit values.

napi_reuse_skb() makes sure to clear skb->vlan_all,
as it already calls __vlan_hwaccel_clear_tag()

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
gro: avoid checking for a failed search 2022-11-10T10:26:47+00:00 Richard Gobert richardbgobert@gmail.com 2022-11-08T12:33:28+00:00 e081ecf084d31809242fb0b9f35484d5fb3a161a After searching for a protocol handler in dev_gro_receive, checking for failure is redundant. Skip the failure code after finding the corresponding handler. Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Richard Gobert <richardbgobert@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20221108123320.GA59373@debian Signed-off-by: Paolo Abeni <pabeni@redhat.com> 
After searching for a protocol handler in dev_gro_receive, checking for
failure is redundant. Skip the failure code after finding the
corresponding handler.

Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Richard Gobert <richardbgobert@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20221108123320.GA59373@debian
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
gro: add support of (hw)gro packets to gro stack 2022-10-03T11:38:34+00:00 Coco Li lixiaoyan@google.com 2022-09-30T22:09:05+00:00 5eddb24901ee49eee23c0bfce6af2e83fd5679bd Current GRO stack only supports incoming packets containing one frame/MSS. This patch changes GRO to accept packets that are already GRO. HW-GRO (aka RSC for some vendors) is very often limited in presence of interleaved packets. Linux SW GRO stack can complete the job and provide larger GRO packets, thus reducing rate of ACK packets and cpu overhead. This also means BIG TCP can still be used, even if HW-GRO/RSC was able to cook ~64 KB GRO packets. v2: fix logic in tcp_gro_receive() Only support TCP for the moment (Paolo) Co-Developed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Coco Li <lixiaoyan@google.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Current GRO stack only supports incoming packets containing
one frame/MSS.

This patch changes GRO to accept packets that are already GRO.

HW-GRO (aka RSC for some vendors) is very often limited in presence
of interleaved packets. Linux SW GRO stack can complete the job
and provide larger GRO packets, thus reducing rate of ACK packets
and cpu overhead.

This also means BIG TCP can still be used, even if HW-GRO/RSC was
able to cook ~64 KB GRO packets.

v2: fix logic in tcp_gro_receive()

    Only support TCP for the moment (Paolo)

Co-Developed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Coco Li <lixiaoyan@google.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: allow gro_max_size to exceed 65536 2022-05-16T09:18:56+00:00 Alexander Duyck alexanderduyck@fb.com 2022-05-13T18:34:03+00:00 0fe79f28bfaf73b66b7b1562d2468f94aa03bd12 Allow the gro_max_size to exceed a value larger than 65536. There weren't really any external limitations that prevented this other than the fact that IPv4 only supports a 16 bit length field. Since we have the option of adding a hop-by-hop header for IPv6 we can allow IPv6 to exceed this value and for IPv4 and non-TCP flows we can cap things at 65536 via a constant rather than relying on gro_max_size. [edumazet] limit GRO_MAX_SIZE to (8 * 65535) to avoid overflows. Signed-off-by: Alexander Duyck <alexanderduyck@fb.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Allow the gro_max_size to exceed a value larger than 65536.

There weren't really any external limitations that prevented this other
than the fact that IPv4 only supports a 16 bit length field. Since we have
the option of adding a hop-by-hop header for IPv6 we can allow IPv6 to
exceed this value and for IPv4 and non-TCP flows we can cap things at 65536
via a constant rather than relying on gro_max_size.

[edumazet] limit GRO_MAX_SIZE to (8 * 65535) to avoid overflows.

Signed-off-by: Alexander Duyck <alexanderduyck@fb.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-03-11T01:16:56+00:00 Jakub Kicinski kuba@kernel.org 2022-03-11T01:16:56+00:00 1e8a3f0d2a1ef544611a7ea4a7c1512c732e0e43 net/dsa/dsa2.c commit afb3cc1a397d ("net: dsa: unlock the rtnl_mutex when dsa_master_setup() fails") commit e83d56537859 ("net: dsa: replay master state events in dsa_tree_{setup,teardown}_master") https://lore.kernel.org/all/20220307101436.7ae87da0@canb.auug.org.au/ drivers/net/ethernet/intel/ice/ice.h commit 97b0129146b1 ("ice: Fix error with handling of bonding MTU") commit 43113ff73453 ("ice: add TTY for GNSS module for E810T device") https://lore.kernel.org/all/20220310112843.3233bcf1@canb.auug.org.au/ drivers/staging/gdm724x/gdm_lte.c commit fc7f750dc9d1 ("staging: gdm724x: fix use after free in gdm_lte_rx()") commit 4bcc4249b4cf ("staging: Use netif_rx().") https://lore.kernel.org/all/20220308111043.1018a59d@canb.auug.org.au/ Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
net/dsa/dsa2.c
  commit afb3cc1a397d ("net: dsa: unlock the rtnl_mutex when dsa_master_setup() fails")
  commit e83d56537859 ("net: dsa: replay master state events in dsa_tree_{setup,teardown}_master")
https://lore.kernel.org/all/20220307101436.7ae87da0@canb.auug.org.au/

drivers/net/ethernet/intel/ice/ice.h
  commit 97b0129146b1 ("ice: Fix error with handling of bonding MTU")
  commit 43113ff73453 ("ice: add TTY for GNSS module for E810T device")
https://lore.kernel.org/all/20220310112843.3233bcf1@canb.auug.org.au/

drivers/staging/gdm724x/gdm_lte.c
  commit fc7f750dc9d1 ("staging: gdm724x: fix use after free in gdm_lte_rx()")
  commit 4bcc4249b4cf ("staging: Use netif_rx().")
https://lore.kernel.org/all/20220308111043.1018a59d@canb.auug.org.au/

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net: Fix esp GSO on inter address family tunnels. 2022-03-07T12:14:04+00:00 Steffen Klassert steffen.klassert@secunet.com 2022-03-07T12:11:41+00:00 23c7f8d7989e1646aac82f75761b7648c355cb8a The esp tunnel GSO handlers use skb_mac_gso_segment to push the inner packet to the segmentation handlers. However, skb_mac_gso_segment takes the Ethernet Protocol ID from 'skb->protocol' which is wrong for inter address family tunnels. We fix this by introducing a new skb_eth_gso_segment function. This function can be used if it is necessary to pass the Ethernet Protocol ID directly to the segmentation handler. First users of this function will be the esp4 and esp6 tunnel segmentation handlers. Fixes: c35fe4106b92 ("xfrm: Add mode handlers for IPsec on layer 2") Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> 
The esp tunnel GSO handlers use skb_mac_gso_segment to
push the inner packet to the segmentation handlers.
However, skb_mac_gso_segment takes the Ethernet Protocol
ID from 'skb->protocol' which is wrong for inter address
family tunnels. We fix this by introducing a new
skb_eth_gso_segment function.

This function can be used if it is necessary to pass the
Ethernet Protocol ID directly to the segmentation handler.
First users of this function will be the esp4 and esp6
tunnel segmentation handlers.

Fixes: c35fe4106b92 ("xfrm: Add mode handlers for IPsec on layer 2")
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
net: gro: minor optimization for dev_gro_receive() 2022-02-05T15:13:52+00:00 Paolo Abeni pabeni@redhat.com 2022-02-04T11:28:37+00:00 de5a1f3ce4c862150dc442530dba19e1d1dc6bc2 While inspecting some perf report, I noticed that the compiler emits suboptimal code for the napi CB initialization, fetching and storing multiple times the memory for flags bitfield. This is with gcc 10.3.1, but I observed the same with older compiler versions. We can help the compiler to do a nicer work clearing several fields at once using an u32 alias. The generated code is quite smaller, with the same number of conditional. Before: objdump -t net/core/gro.o | grep " F .text" 0000000000000bb0 l F .text 0000000000000357 dev_gro_receive After: 0000000000000bb0 l F .text 000000000000033c dev_gro_receive v1 -> v2: - use struct_group (Alexander and Alex) RFC -> v1: - use __struct_group to delimit the zeroed area (Alexander) Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
While inspecting some perf report, I noticed that the compiler
emits suboptimal code for the napi CB initialization, fetching
and storing multiple times the memory for flags bitfield.
This is with gcc 10.3.1, but I observed the same with older compiler
versions.

We can help the compiler to do a nicer work clearing several
fields at once using an u32 alias. The generated code is quite
smaller, with the same number of conditional.

Before:
objdump -t net/core/gro.o | grep " F .text"
0000000000000bb0 l     F .text	0000000000000357 dev_gro_receive

After:
0000000000000bb0 l     F .text	000000000000033c dev_gro_receive

v1  -> v2:
 - use struct_group (Alexander and Alex)

RFC -> v1:
 - use __struct_group to delimit the zeroed area (Alexander)

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: gro: avoid re-computing truesize twice on recycle 2022-02-05T15:13:52+00:00 Paolo Abeni pabeni@redhat.com 2022-02-04T11:28:36+00:00 7881453e4adf497cf9109c84fa21eedda9ac6164 After commit 5e10da5385d2 ("skbuff: allow 'slow_gro' for skb carring sock reference") and commit af352460b465 ("net: fix GRO skb truesize update") the truesize of the skb with stolen head is properly updated by the GRO engine, we don't need anymore resetting it at recycle time. v1 -> v2: - clarify the commit message (Alexander) Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
After commit 5e10da5385d2 ("skbuff: allow 'slow_gro' for skb
carring sock reference") and commit af352460b465 ("net: fix GRO
skb truesize update") the truesize of the skb with stolen head is
properly updated by the GRO engine, we don't need anymore resetting
it at recycle time.

v1 -> v2:
 - clarify the commit message (Alexander)

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>