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Maciej Fijalkowski d84f8327af xsk: Fix l2fwd for copy mode + busy poll combo
[ Upstream commit 8de8b71b78 ]

While checking AF_XDP copy mode combined with busy poll, strange
results were observed. rxdrop and txonly scenarios worked fine, but
l2fwd broke immediately.

After a deeper look, it turned out that for l2fwd, Tx side was exiting
early due to xsk_no_wakeup() returning true and in the end
xsk_generic_xmit() was never called. Note that AF_XDP Tx in copy mode
is syscall steered, so the current behavior is broken.

Txonly scenario only worked due to the fact that
sk_mark_napi_id_once_xdp() was never called - since Rx side is not in
the picture for this case and mentioned function is called in
xsk_rcv_check(), sk::sk_napi_id was never set, which in turn meant that
xsk_no_wakeup() was returning false (see the sk->sk_napi_id >=
MIN_NAPI_ID check in there).

To fix this, prefer busy poll in xsk_sendmsg() only when zero copy is
enabled on a given AF_XDP socket. By doing so, busy poll in copy mode
would not exit early on Tx side and eventually xsk_generic_xmit() will
be called.

Fixes: a0731952d9 ("xsk: Add busy-poll support for {recv,send}msg()")
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220406155804.434493-1-maciej.fijalkowski@intel.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-05-09 09:14:32 +02:00
arch arm64: dts: meson: remove CPU opps below 1GHz for SM1 boards 2022-05-09 09:14:31 +02:00
block iocost: don't reset the inuse weight of under-weighted debtors 2022-05-09 09:14:31 +02:00
certs certs: Add support for using elliptic curve keys for signing modules 2021-08-23 19:55:42 +03:00
crypto crypto: xts - Add softdep on ecb 2022-04-08 14:23:55 +02:00
Documentation ext4, doc: fix incorrect h_reserved size 2022-04-27 14:39:01 +02:00
drivers mtd: rawnand: fix ecc parameters for mt7622 2022-05-09 09:14:32 +02:00
fs ceph: fix possible NULL pointer dereference for req->r_session 2022-05-09 09:14:30 +02:00
include hex2bin: make the function hex_to_bin constant-time 2022-05-09 09:14:30 +02:00
init init/main.c: return 1 from handled __setup() functions 2022-04-13 20:59:10 +02:00
ipc ipc/sem: do not sleep with a spin lock held 2022-02-08 18:34:03 +01:00
kernel bpf: Fix crash due to out of bounds access into reg2btf_ids. 2022-05-01 17:22:26 +02:00
lib hex2bin: fix access beyond string end 2022-05-09 09:14:30 +02:00
LICENSES LICENSES/dual/CC-BY-4.0: Git rid of "smart quotes" 2021-07-15 06:31:24 -06:00
mm mm: gup: make fault_in_safe_writeable() use fixup_user_fault() 2022-05-01 17:22:34 +02:00
net xsk: Fix l2fwd for copy mode + busy poll combo 2022-05-09 09:14:32 +02:00
samples samples/bpf, xdpsock: Fix race when running for fix duration of time 2022-04-08 14:23:40 +02:00
scripts gcc-plugins: latent_entropy: use /dev/urandom 2022-04-20 09:34:18 +02:00
security Fix incorrect type in assignment of ipv6 port for audit 2022-04-08 14:23:55 +02:00
sound ASoC: soc-dapm: fix two incorrect uses of list iterator 2022-04-27 14:39:00 +02:00
tools selftests/bpf: Add test for reg2btf_ids out of bounds access 2022-05-01 17:22:34 +02:00
usr usr/include/Makefile: add linux/nfc.h to the compile-test coverage 2022-02-01 17:27:15 +01:00
virt KVM: avoid NULL pointer dereference in kvm_dirty_ring_push 2022-04-13 20:59:26 +02:00
.clang-format clang-format: Update with the latest for_each macro list 2021-05-12 23:32:39 +02:00
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore .gitignore: ignore only top-level modules.builtin 2021-05-02 00:43:35 +09:00
.mailmap mailmap: add Andrej Shadura 2021-10-18 20:22:03 -10:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Daniel Drake to credits 2021-09-21 08:34:58 +03:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS MAINTAINERS: adjust file entry for of_net.c after movement 2022-03-08 19:12:53 +01:00
Makefile Linux 5.15.37 2022-05-01 17:22:35 +02:00
README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
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There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
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the problems which may result by upgrading your kernel.