Several net tests requires an XDP program build under the ebpf
directory, and error out if such program is not available.

That makes running successful net test hard, let's duplicate into the
net dir the [very small] program, re-using the existing rules to build
it, and finally dropping the bogus dependency.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/28e7af7c031557f691dc8045ee41dd549dd5e74c.1706131762.git.pabeni@redhat.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Still a bit unclear whether each directory should have its own
config file, but assuming they should lets add one for tcp_ao.

The following tests still fail with this config in place:
 - rst_ipv4,
 - rst_ipv6,
 - bench-lookups_ipv6.
other 21 pass.

Fixes: d11301f6 ("selftests/net: Add TCP-AO ICMPs accept test")
Reviewed-by: Dmitry Safonov <0x7f454c46@gmail.com>
Link: https://lore.kernel.org/r/20240124192550.1865743-1-kuba@kernel.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Pull networking fixes from Paolo Abeni:
 "Including fixes from bpf, netfilter and WiFi.

  Jakub is doing a lot of work to include the self-tests in our CI, as a
  result a significant amount of self-tests related fixes is flowing in
  (and will likely continue in the next few weeks).

  Current release - regressions:

   - bpf: fix a kernel crash for the riscv 64 JIT

   - bnxt_en: fix memory leak in bnxt_hwrm_get_rings()

   - revert "net: macsec: use skb_ensure_writable_head_tail to expand
     the skb"

  Previous releases - regressions:

   - core: fix removing a namespace with conflicting altnames

   - tc/flower: fix chain template offload memory leak

   - tcp:
      - make sure init the accept_queue's spinlocks once
      - fix autocork on CPUs with weak memory model

   - udp: fix busy polling

   - mlx5e:
      - fix out-of-bound read in port timestamping
      - fix peer flow lists corruption

   - iwlwifi: fix a memory corruption

  Previous releases - always broken:

   - netfilter:
      - nft_chain_filter: handle NETDEV_UNREGISTER for inet/ingress
        basechain
      - nft_limit: reject configurations that cause integer overflow

   - bpf: fix bpf_xdp_adjust_tail() with XSK zero-copy mbuf, avoiding a
     NULL pointer dereference upon shrinking

   - llc: make llc_ui_sendmsg() more robust against bonding changes

   - smc: fix illegal rmb_desc access in SMC-D connection dump

   - dpll: fix pin dump crash for rebound module

   - bnxt_en: fix possible crash after creating sw mqprio TCs

   - hv_netvsc: calculate correct ring size when PAGE_SIZE is not 4kB

  Misc:

   - several self-tests fixes for better integration with the netdev CI

   - added several missing modules descriptions"

* tag 'net-6.8-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (88 commits)
  tsnep: Fix XDP_RING_NEED_WAKEUP for empty fill ring
  tsnep: Remove FCS for XDP data path
  net: fec: fix the unhandled context fault from smmu
  selftests: bonding: do not test arp/ns target with mode balance-alb/tlb
  fjes: fix memleaks in fjes_hw_setup
  i40e: update xdp_rxq_info::frag_size for ZC enabled Rx queue
  i40e: set xdp_rxq_info::frag_size
  xdp: reflect tail increase for MEM_TYPE_XSK_BUFF_POOL
  ice: update xdp_rxq_info::frag_size for ZC enabled Rx queue
  intel: xsk: initialize skb_frag_t::bv_offset in ZC drivers
  ice: remove redundant xdp_rxq_info registration
  i40e: handle multi-buffer packets that are shrunk by xdp prog
  ice: work on pre-XDP prog frag count
  xsk: fix usage of multi-buffer BPF helpers for ZC XDP
  xsk: make xsk_buff_pool responsible for clearing xdp_buff::flags
  xsk: recycle buffer in case Rx queue was full
  net: fill in MODULE_DESCRIPTION()s for rvu_mbox
  net: fill in MODULE_DESCRIPTION()s for litex
  net: fill in MODULE_DESCRIPTION()s for fsl_pq_mdio
  net: fill in MODULE_DESCRIPTION()s for fec
  ...

Pull overlayfs fix from Amir Goldstein:
 "Change the on-disk format for the new "xwhiteouts" feature introduced
  in v6.7

  The change reduces unneeded overhead of an extra getxattr per readdir.
  The only user of the "xwhiteout" feature is the external composefs
  tool, which has been updated to support the new on-disk format.

  This change is also designated for 6.7.y"

* tag 'ovl-fixes-6.8-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/overlayfs/vfs:
  ovl: mark xwhiteouts directory with overlay.opaque='x'

Pull netfs fixes from Christian Brauner:
 "This contains various fixes for the netfs work merged earlier this
  cycle:

  afs:
   - Fix locking imbalance in afs_proc_addr_prefs_show()
   - Remove afs_dynroot_d_revalidate() which is redundant
   - Fix error handling during lookup
   - Hide sillyrenames from userspace. This fixes a race between
     silly-rename files being created/removed and userspace iterating
     over directory entries
   - Don't use unnecessary folio_*() functions

  cifs:
   - Don't use unnecessary folio_*() functions

  cachefiles:
   - erofs: Fix Null dereference when cachefiles are not doing
     ondemand-mode
   - Update mailing list

  netfs library:
   - Add Jeff Layton as reviewer
   - Update mailing list
   - Fix a error checking in netfs_perform_write()
   - fscache: Check error before dereferencing
   - Don't use unnecessary folio_*() functions"

* tag 'vfs-6.8-rc2.netfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  afs: Fix missing/incorrect unlocking of RCU read lock
  afs: Remove afs_dynroot_d_revalidate() as it is redundant
  afs: Fix error handling with lookup via FS.InlineBulkStatus
  afs: Hide silly-rename files from userspace
  cachefiles, erofs: Fix NULL deref in when cachefiles is not doing ondemand-mode
  netfs: Fix a NULL vs IS_ERR() check in netfs_perform_write()
  netfs, fscache: Prevent Oops in fscache_put_cache()
  cifs: Don't use certain unnecessary folio_*() functions
  afs: Don't use certain unnecessary folio_*() functions
  netfs: Don't use certain unnecessary folio_*() functions
  netfs: Add Jeff Layton as reviewer
  netfs, cachefiles: Change mailing list

Pull nfsd fixes from Chuck Lever:

 - Fix in-kernel RPC UDP transport

 - Fix NFSv4.0 RELEASE_LOCKOWNER

* tag 'nfsd-6.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux:
  nfsd: fix RELEASE_LOCKOWNER
  SUNRPC: use request size to initialize bio_vec in svc_udp_sendto()

Pull RCU fix from Neeraj Upadhyay:
 "This fixes RCU grace period stalls, which are observed when an
  outgoing CPU's quiescent state reporting results in wakeup of one of
  the grace period kthreads, to complete the grace period.

  If those kthreads have SCHED_FIFO policy, the wake up can indirectly
  arm the RT bandwith timer to the local offline CPU.

  Earlier migration of the hrtimers from the CPU introduced in commit
  5c0930cc ("hrtimers: Push pending hrtimers away from outgoing CPU
  earlier") results in this timer getting ignored.

  If the RCU grace period kthreads are waiting for RT bandwidth to be
  available, they may never be actually scheduled, resulting in RCU
  stall warnings"

* tag 'urgent-rcu.2024.01.24a' of https://github.com/neeraju/linux:
  rcu: Defer RCU kthreads wakeup when CPU is dying

Gerhard Engleder says:

====================
tsnep: XDP fixes

Found two driver specific problems during XDP and XSK testing.
====================

Link: https://lore.kernel.org/r/20240123200918.61219-1-gerhard@engleder-embedded.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>

The fill ring of the XDP socket may contain not enough buffers to
completey fill the RX queue during socket creation. In this case the
flag XDP_RING_NEED_WAKEUP is not set as this flag is only set if the RX
queue is not completely filled during polling.

Set XDP_RING_NEED_WAKEUP flag also if RX queue is not completely filled
during XDP socket creation.

Fixes: 3fc23339 ("tsnep: Add XDP socket zero-copy RX support")
Signed-off-by: Gerhard Engleder <gerhard@engleder-embedded.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

The RX data buffer includes the FCS. The FCS is already stripped for the
normal data path. But for the XDP data path the FCS is included and
acts like additional/useless data.

Remove the FCS from the RX data buffer also for XDP.

Fixes: 65b28c81 ("tsnep: Add XDP RX support")
Fixes: 3fc23339 ("tsnep: Add XDP socket zero-copy RX support")
Signed-off-by: Gerhard Engleder <gerhard@engleder-embedded.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Saeed Mahameed says:

====================
mlx5 fixes 2024-01-24

This series provides bug fixes to mlx5 driver.
Please pull and let me know if there is any problem.

* tag 'mlx5-fixes-2024-01-24' of git://git.kernel.org/pub/scm/linux/kernel/git/saeed/linux:
  net/mlx5e: fix a potential double-free in fs_any_create_groups
  net/mlx5e: fix a double-free in arfs_create_groups
  net/mlx5e: Ignore IPsec replay window values on sender side
  net/mlx5e: Allow software parsing when IPsec crypto is enabled
  net/mlx5: Use mlx5 device constant for selecting CQ period mode for ASO
  net/mlx5: DR, Can't go to uplink vport on RX rule
  net/mlx5: DR, Use the right GVMI number for drop action
  net/mlx5: Bridge, fix multicast packets sent to uplink
  net/mlx5: Fix a WARN upon a callback command failure
  net/mlx5e: Fix peer flow lists handling
  net/mlx5e: Fix inconsistent hairpin RQT sizes
  net/mlx5e: Fix operation precedence bug in port timestamping napi_poll context
  net/mlx5: Fix query of sd_group field
  net/mlx5e: Use the correct lag ports number when creating TISes
====================

Link: https://lore.kernel.org/r/20240124081855.115410-1-saeed@kernel.orgSigned-off-by: Paolo Abeni <pabeni@redhat.com>

Daniel Borkmann says:

====================
pull-request: bpf 2024-01-25

The following pull-request contains BPF updates for your *net* tree.

We've added 12 non-merge commits during the last 2 day(s) which contain
a total of 13 files changed, 190 insertions(+), 91 deletions(-).

The main changes are:

1) Fix bpf_xdp_adjust_tail() in context of XSK zero-copy drivers which
   support XDP multi-buffer. The former triggered a NULL pointer
   dereference upon shrinking, from Maciej Fijalkowski & Tirthendu Sarkar.

2) Fix a bug in riscv64 BPF JIT which emitted a wrong prologue and
   epilogue for struct_ops programs, from Pu Lehui.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  i40e: update xdp_rxq_info::frag_size for ZC enabled Rx queue
  i40e: set xdp_rxq_info::frag_size
  xdp: reflect tail increase for MEM_TYPE_XSK_BUFF_POOL
  ice: update xdp_rxq_info::frag_size for ZC enabled Rx queue
  intel: xsk: initialize skb_frag_t::bv_offset in ZC drivers
  ice: remove redundant xdp_rxq_info registration
  i40e: handle multi-buffer packets that are shrunk by xdp prog
  ice: work on pre-XDP prog frag count
  xsk: fix usage of multi-buffer BPF helpers for ZC XDP
  xsk: make xsk_buff_pool responsible for clearing xdp_buff::flags
  xsk: recycle buffer in case Rx queue was full
  riscv, bpf: Fix unpredictable kernel crash about RV64 struct_ops
====================

Link: https://lore.kernel.org/r/20240125084416.10876-1-daniel@iogearbox.netSigned-off-by: Paolo Abeni <pabeni@redhat.com>

When repeatedly changing the interface link speed using the command below:

ethtool -s eth0 speed 100 duplex full
ethtool -s eth0 speed 1000 duplex full

The following errors may sometimes be reported by the ARM SMMU driver:

[ 5395.035364] fec 5b040000.ethernet eth0: Link is Down
[ 5395.039255] arm-smmu 51400000.iommu: Unhandled context fault:
fsr=0x402, iova=0x00000000, fsynr=0x100001, cbfrsynra=0x852, cb=2
[ 5398.108460] fec 5b040000.ethernet eth0: Link is Up - 100Mbps/Full -
flow control off

It is identified that the FEC driver does not properly stop the TX queue
during the link speed transitions, and this results in the invalid virtual
I/O address translations from the SMMU and causes the context faults.

Fixes: dbc64a8e ("net: fec: move calls to quiesce/resume packet processing out of fec_restart()")
Signed-off-by: Shenwei Wang <shenwei.wang@nxp.com>
Link: https://lore.kernel.org/r/20240123165141.2008104-1-shenwei.wang@nxp.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>

The prio_arp/ns tests hard code the mode to active-backup. At the same
time, The balance-alb/tlb modes do not support arp/ns target. So remove
the prio_arp/ns tests from the loop and only test active-backup mode.

Fixes: 481b56e0 ("selftests: bonding: re-format bond option tests")
Reported-by: Jay Vosburgh <jay.vosburgh@canonical.com>
Closes: https://lore.kernel.org/netdev/17415.1705965957@famine/Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Acked-by: Jay Vosburgh <jay.vosburgh@canonical.com>
Link: https://lore.kernel.org/r/20240123075917.1576360-1-liuhangbin@gmail.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for net:

1) Update nf_tables kdoc to keep it in sync with the code, from George Guo.

2) Handle NETDEV_UNREGISTER event for inet/ingress basechain.

3) Reject configuration that cause nft_limit to overflow,
   from Florian Westphal.

4) Restrict anonymous set/map names to 16 bytes, from Florian Westphal.

5) Disallow to encode queue number and error in verdicts. This reverts
   a patch which seems to have introduced an early attempt to support for
   nfqueue maps, which is these days supported via nft_queue expression.

6) Sanitize family via .validate for expressions that explicitly refer
   to NF_INET_* hooks.

* tag 'nf-24-01-24' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  netfilter: nf_tables: validate NFPROTO_* family
  netfilter: nf_tables: reject QUEUE/DROP verdict parameters
  netfilter: nf_tables: restrict anonymous set and map names to 16 bytes
  netfilter: nft_limit: reject configurations that cause integer overflow
  netfilter: nft_chain_filter: handle NETDEV_UNREGISTER for inet/ingress basechain
  netfilter: nf_tables: cleanup documentation
====================

Link: https://lore.kernel.org/r/20240124191248.75463-1-pablo@netfilter.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

In fjes_hw_setup, it allocates several memory and delay the deallocation
to the fjes_hw_exit in fjes_probe through the following call chain:

fjes_probe
  |-> fjes_hw_init
        |-> fjes_hw_setup
  |-> fjes_hw_exit

However, when fjes_hw_setup fails, fjes_hw_exit won't be called and thus
all the resources allocated in fjes_hw_setup will be leaked. In this
patch, we free those resources in fjes_hw_setup and prevents such leaks.

Fixes: 2fcbca68 ("fjes: platform_driver's .probe and .remove routine")
Signed-off-by: Zhipeng Lu <alexious@zju.edu.cn>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240122172445.3841883-1-alexious@zju.edu.cnSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Pull ceph fixes from Ilya Dryomov:
 "A fix to avoid triggering an assert in some cases where RBD exclusive
  mappings are involved and a deprecated API cleanup"

* tag 'ceph-for-6.8-rc2' of https://github.com/ceph/ceph-client:
  rbd: don't move requests to the running list on errors
  rbd: remove usage of the deprecated ida_simple_*() API

Merge tag 'integrity-v6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity

Pull integrity fix from Mimi Zohar:
 "Revert patch that required user-provided key data, since keys can be
  created from kernel-generated random numbers"

* tag 'integrity-v6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
  Revert "KEYS: encrypted: Add check for strsep"

Maciej Fijalkowski says:

====================
net: bpf_xdp_adjust_tail() and Intel mbuf fixes

Hey,

after a break followed by dealing with sickness, here is a v6 that makes
bpf_xdp_adjust_tail() actually usable for ZC drivers that support XDP
multi-buffer. Since v4 I tried also using bpf_xdp_adjust_tail() with
positive offset which exposed yet another issues, which can be observed
by increased commit count when compared to v3.

John, in the end I think we should remove handling
MEM_TYPE_XSK_BUFF_POOL from __xdp_return(), but it is out of the scope
for fixes set, IMHO.

Thanks,
Maciej

v6:
- add acks [Magnus]
- fix spelling mistakes [Magnus]
- avoid touching xdp_buff in xp_alloc_{reused,new_from_fq}() [Magnus]
- s/shrink_data/bpf_xdp_shrink_data [Jakub]
- remove __shrink_data() [Jakub]
- check retvals from __xdp_rxq_info_reg() [Magnus]

v5:
- pick correct version of patch 5 [Simon]
- elaborate a bit more on what patch 2 fixes

v4:
- do not clear frags flag when deleting tail; xsk_buff_pool now does
  that
- skip some NULL tests for xsk_buff_get_tail [Martin, John]
- address problems around registering xdp_rxq_info
- fix bpf_xdp_frags_increase_tail() for ZC mbuf

v3:
- add acks
- s/xsk_buff_tail_del/xsk_buff_del_tail
- address i40e as well (thanks Tirthendu)

v2:
- fix !CONFIG_XDP_SOCKETS builds
- add reviewed-by tag to patch 3
====================

Link: https://lore.kernel.org/r/20240124191602.566724-1-maciej.fijalkowski@intel.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Now that i40e driver correctly sets up frag_size in xdp_rxq_info, let us
make it work for ZC multi-buffer as well. i40e_ring::rx_buf_len for ZC
is being set via xsk_pool_get_rx_frame_size() and this needs to be
propagated up to xdp_rxq_info.

Fixes: 1c9ba9c1 ("i40e: xsk: add RX multi-buffer support")
Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/r/20240124191602.566724-12-maciej.fijalkowski@intel.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

i40e support XDP multi-buffer so it is supposed to use
__xdp_rxq_info_reg() instead of xdp_rxq_info_reg() and set the
frag_size. It can not be simply converted at existing callsite because
rx_buf_len could be un-initialized, so let us register xdp_rxq_info
within i40e_configure_rx_ring(), which happen to be called with already
initialized rx_buf_len value.

Commit 5180ff13 ("i40e: use int for i40e_status") converted 'err' to
int, so two variables to deal with return codes are not needed within
i40e_configure_rx_ring(). Remove 'ret' and use 'err' to handle status
from xdp_rxq_info registration.

Fixes: e213ced1 ("i40e: add support for XDP multi-buffer Rx")
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/r/20240124191602.566724-11-maciej.fijalkowski@intel.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

XSK ZC Rx path calculates the size of data that will be posted to XSK Rx
queue via subtracting xdp_buff::data_end from xdp_buff::data.

In bpf_xdp_frags_increase_tail(), when underlying memory type of
xdp_rxq_info is MEM_TYPE_XSK_BUFF_POOL, add offset to data_end in tail
fragment, so that later on user space will be able to take into account
the amount of bytes added by XDP program.

Fixes: 24ea5012 ("xsk: support mbuf on ZC RX")
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/r/20240124191602.566724-10-maciej.fijalkowski@intel.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Now that ice driver correctly sets up frag_size in xdp_rxq_info, let us
make it work for ZC multi-buffer as well. ice_rx_ring::rx_buf_len for ZC
is being set via xsk_pool_get_rx_frame_size() and this needs to be
propagated up to xdp_rxq_info.

Use a bigger hammer and instead of unregistering only xdp_rxq_info's
memory model, unregister it altogether and register it again and have
xdp_rxq_info with correct frag_size value.

Fixes: 1bbc04de ("ice: xsk: add RX multi-buffer support")
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/r/20240124191602.566724-9-maciej.fijalkowski@intel.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Ice and i40e ZC drivers currently set offset of a frag within
skb_shared_info to 0, which is incorrect. xdp_buffs that come from
xsk_buff_pool always have 256 bytes of a headroom, so they need to be
taken into account to retrieve xdp_buff::data via skb_frag_address().
Otherwise, bpf_xdp_frags_increase_tail() would be starting its job from
xdp_buff::data_hard_start which would result in overwriting existing
payload.

Fixes: 1c9ba9c1 ("i40e: xsk: add RX multi-buffer support")
Fixes: 1bbc04de ("ice: xsk: add RX multi-buffer support")
Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/r/20240124191602.566724-8-maciej.fijalkowski@intel.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

xdp_rxq_info struct can be registered by drivers via two functions -
xdp_rxq_info_reg() and __xdp_rxq_info_reg(). The latter one allows
drivers that support XDP multi-buffer to set up xdp_rxq_info::frag_size
which in turn will make it possible to grow the packet via
bpf_xdp_adjust_tail() BPF helper.

Currently, ice registers xdp_rxq_info in two spots:
1) ice_setup_rx_ring() // via xdp_rxq_info_reg(), BUG
2) ice_vsi_cfg_rxq()   // via __xdp_rxq_info_reg(), OK

Cited commit under fixes tag took care of setting up frag_size and
updated registration scheme in 2) but it did not help as
1) is called before 2) and as shown above it uses old registration
function. This means that 2) sees that xdp_rxq_info is already
registered and never calls __xdp_rxq_info_reg() which leaves us with
xdp_rxq_info::frag_size being set to 0.

To fix this misbehavior, simply remove xdp_rxq_info_reg() call from
ice_setup_rx_ring().

Fixes: 2fba7dc5 ("ice: Add support for XDP multi-buffer on Rx side")
Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/r/20240124191602.566724-7-maciej.fijalkowski@intel.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

XDP programs can shrink packets by calling the bpf_xdp_adjust_tail()
helper function. For multi-buffer packets this may lead to reduction of
frag count stored in skb_shared_info area of the xdp_buff struct. This
results in issues with the current handling of XDP_PASS and XDP_DROP
cases.

For XDP_PASS, currently skb is being built using frag count of
xdp_buffer before it was processed by XDP prog and thus will result in
an inconsistent skb when frag count gets reduced by XDP prog. To fix
this, get correct frag count while building the skb instead of using
pre-obtained frag count.

For XDP_DROP, current page recycling logic will not reuse the page but
instead will adjust the pagecnt_bias so that the page can be freed. This
again results in inconsistent behavior as the page refcnt has already
been changed by the helper while freeing the frag(s) as part of
shrinking the packet. To fix this, only adjust pagecnt_bias for buffers
that are stillpart of the packet post-xdp prog run.

Fixes: e213ced1 ("i40e: add support for XDP multi-buffer Rx")
Reported-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Tirthendu Sarkar <tirthendu.sarkar@intel.com>
Link: https://lore.kernel.org/r/20240124191602.566724-6-maciej.fijalkowski@intel.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Fix an OOM panic in XDP_DRV mode when a XDP program shrinks a
multi-buffer packet by 4k bytes and then redirects it to an AF_XDP
socket.

Since support for handling multi-buffer frames was added to XDP, usage
of bpf_xdp_adjust_tail() helper within XDP program can free the page
that given fragment occupies and in turn decrease the fragment count
within skb_shared_info that is embedded in xdp_buff struct. In current
ice driver codebase, it can become problematic when page recycling logic
decides not to reuse the page. In such case, __page_frag_cache_drain()
is used with ice_rx_buf::pagecnt_bias that was not adjusted after
refcount of page was changed by XDP prog which in turn does not drain
the refcount to 0 and page is never freed.

To address this, let us store the count of frags before the XDP program
was executed on Rx ring struct. This will be used to compare with
current frag count from skb_shared_info embedded in xdp_buff. A smaller
value in the latter indicates that XDP prog freed frag(s). Then, for
given delta decrement pagecnt_bias for XDP_DROP verdict.

While at it, let us also handle the EOP frag within
ice_set_rx_bufs_act() to make our life easier, so all of the adjustments
needed to be applied against freed frags are performed in the single
place.

Fixes: 2fba7dc5 ("ice: Add support for XDP multi-buffer on Rx side")
Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/r/20240124191602.566724-5-maciej.fijalkowski@intel.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Currently when packet is shrunk via bpf_xdp_adjust_tail() and memory
type is set to MEM_TYPE_XSK_BUFF_POOL, null ptr dereference happens:

[1136314.192256] BUG: kernel NULL pointer dereference, address:
0000000000000034
[1136314.203943] #PF: supervisor read access in kernel mode
[1136314.213768] #PF: error_code(0x0000) - not-present page
[1136314.223550] PGD 0 P4D 0
[1136314.230684] Oops: 0000 [#1] PREEMPT SMP NOPTI
[1136314.239621] CPU: 8 PID: 54203 Comm: xdpsock Not tainted 6.6.0+ #257
[1136314.250469] Hardware name: Intel Corporation S2600WFT/S2600WFT,
BIOS SE5C620.86B.02.01.0008.031920191559 03/19/2019
[1136314.265615] RIP: 0010:__xdp_return+0x6c/0x210
[1136314.274653] Code: ad 00 48 8b 47 08 49 89 f8 a8 01 0f 85 9b 01 00 00 0f 1f 44 00 00 f0 41 ff 48 34 75 32 4c 89 c7 e9 79 cd 80 ff 83 fe 03 75 17 <f6> 41 34 01 0f 85 02 01 00 00 48 89 cf e9 22 cc 1e 00 e9 3d d2 86
[1136314.302907] RSP: 0018:ffffc900089f8db0 EFLAGS: 00010246
[1136314.312967] RAX: ffffc9003168aed0 RBX: ffff8881c3300000 RCX:
0000000000000000
[1136314.324953] RDX: 0000000000000000 RSI: 0000000000000003 RDI:
ffffc9003168c000
[1136314.336929] RBP: 0000000000000ae0 R08: 0000000000000002 R09:
0000000000010000
[1136314.348844] R10: ffffc9000e495000 R11: 0000000000000040 R12:
0000000000000001
[1136314.360706] R13: 0000000000000524 R14: ffffc9003168aec0 R15:
0000000000000001
[1136314.373298] FS:  00007f8df8bbcb80(0000) GS:ffff8897e0e00000(0000)
knlGS:0000000000000000
[1136314.386105] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[1136314.396532] CR2: 0000000000000034 CR3: 00000001aa912002 CR4:
00000000007706f0
[1136314.408377] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
0000000000000000
[1136314.420173] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7:
0000000000000400
[1136314.431890] PKRU: 55555554
[1136314.439143] Call Trace:
[1136314.446058]  <IRQ>
[1136314.452465]  ? __die+0x20/0x70
[1136314.459881]  ? page_fault_oops+0x15b/0x440
[1136314.468305]  ? exc_page_fault+0x6a/0x150
[1136314.476491]  ? asm_exc_page_fault+0x22/0x30
[1136314.484927]  ? __xdp_return+0x6c/0x210
[1136314.492863]  bpf_xdp_adjust_tail+0x155/0x1d0
[1136314.501269]  bpf_prog_ccc47ae29d3b6570_xdp_sock_prog+0x15/0x60
[1136314.511263]  ice_clean_rx_irq_zc+0x206/0xc60 [ice]
[1136314.520222]  ? ice_xmit_zc+0x6e/0x150 [ice]
[1136314.528506]  ice_napi_poll+0x467/0x670 [ice]
[1136314.536858]  ? ttwu_do_activate.constprop.0+0x8f/0x1a0
[1136314.546010]  __napi_poll+0x29/0x1b0
[1136314.553462]  net_rx_action+0x133/0x270
[1136314.561619]  __do_softirq+0xbe/0x28e
[1136314.569303]  do_softirq+0x3f/0x60

This comes from __xdp_return() call with xdp_buff argument passed as
NULL which is supposed to be consumed by xsk_buff_free() call.

To address this properly, in ZC case, a node that represents the frag
being removed has to be pulled out of xskb_list. Introduce
appropriate xsk helpers to do such node operation and use them
accordingly within bpf_xdp_adjust_tail().

Fixes: 24ea5012 ("xsk: support mbuf on ZC RX")
Acked-by: Magnus Karlsson <magnus.karlsson@intel.com> # For the xsk header part
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/r/20240124191602.566724-4-maciej.fijalkowski@intel.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

XDP multi-buffer support introduced XDP_FLAGS_HAS_FRAGS flag that is
used by drivers to notify data path whether xdp_buff contains fragments
or not. Data path looks up mentioned flag on first buffer that occupies
the linear part of xdp_buff, so drivers only modify it there. This is
sufficient for SKB and XDP_DRV modes as usually xdp_buff is allocated on
stack or it resides within struct representing driver's queue and
fragments are carried via skb_frag_t structs. IOW, we are dealing with
only one xdp_buff.

ZC mode though relies on list of xdp_buff structs that is carried via
xsk_buff_pool::xskb_list, so ZC data path has to make sure that
fragments do *not* have XDP_FLAGS_HAS_FRAGS set. Otherwise,
xsk_buff_free() could misbehave if it would be executed against xdp_buff
that carries a frag with XDP_FLAGS_HAS_FRAGS flag set. Such scenario can
take place when within supplied XDP program bpf_xdp_adjust_tail() is
used with negative offset that would in turn release the tail fragment
from multi-buffer frame.

Calling xsk_buff_free() on tail fragment with XDP_FLAGS_HAS_FRAGS would
result in releasing all the nodes from xskb_list that were produced by
driver before XDP program execution, which is not what is intended -
only tail fragment should be deleted from xskb_list and then it should
be put onto xsk_buff_pool::free_list. Such multi-buffer frame will never
make it up to user space, so from AF_XDP application POV there would be
no traffic running, however due to free_list getting constantly new
nodes, driver will be able to feed HW Rx queue with recycled buffers.
Bottom line is that instead of traffic being redirected to user space,
it would be continuously dropped.

To fix this, let us clear the mentioned flag on xsk_buff_pool side
during xdp_buff initialization, which is what should have been done
right from the start of XSK multi-buffer support.

Fixes: 1bbc04de ("ice: xsk: add RX multi-buffer support")
Fixes: 1c9ba9c1 ("i40e: xsk: add RX multi-buffer support")
Fixes: 24ea5012 ("xsk: support mbuf on ZC RX")
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/r/20240124191602.566724-3-maciej.fijalkowski@intel.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Add missing xsk_buff_free() call when __xsk_rcv_zc() failed to produce
descriptor to XSK Rx queue.

Fixes: 24ea5012 ("xsk: support mbuf on ZC RX")
Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/r/20240124191602.566724-2-maciej.fijalkowski@intel.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Breno Leitao says:

====================
Fix MODULE_DESCRIPTION() for net (p2)

There are hundreds of network modules that misses MODULE_DESCRIPTION(),
causing a warnning when compiling with W=1. Example:

        WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/net/arcnet/com90io.o
        WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/net/arcnet/arc-rimi.o
        WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/net/arcnet/com20020.o

This part2 of the patchset focus on the drivers/net/ethernet drivers.
There are still some missing warnings in drivers/net/ethernet that will
be fixed in an upcoming patchset.

v1: https://lore.kernel.org/all/20240122184543.2501493-2-leitao@debian.org/
====================

Link: https://lore.kernel.org/r/20240123190332.677489-1-leitao@debian.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

W=1 builds now warn if module is built without a MODULE_DESCRIPTION().
Add descriptions to the Marvel RVU mbox driver.
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://lore.kernel.org/r/20240123190332.677489-11-leitao@debian.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

W=1 builds now warn if module is built without a MODULE_DESCRIPTION().
Add descriptions to the LiteX Liteeth Ethernet device.
Signed-off-by: Breno Leitao <leitao@debian.org>
Acked-by: Gabriel Somlo <gsomlo@gmail.com>
Link: https://lore.kernel.org/r/20240123190332.677489-10-leitao@debian.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

W=1 builds now warn if module is built without a MODULE_DESCRIPTION().
Add descriptions to the Freescale PQ MDIO driver.
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://lore.kernel.org/r/20240123190332.677489-9-leitao@debian.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

W=1 builds now warn if module is built without a MODULE_DESCRIPTION().
Add descriptions to the FEC (MPC8xx) Ethernet controller.
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Wei Fang <wei.fang@nxp.com>
Link: https://lore.kernel.org/r/20240123190332.677489-8-leitao@debian.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

W=1 builds now warn if module is built without a MODULE_DESCRIPTION().
Add descriptions to the NXP ENETC Ethernet driver.
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://lore.kernel.org/r/20240123190332.677489-7-leitao@debian.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

W=1 builds now warn if module is built without a MODULE_DESCRIPTION().
Add descriptions to the EZchip NPS ethernet driver.
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://lore.kernel.org/r/20240123190332.677489-6-leitao@debian.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

W=1 builds now warn if module is built without a MODULE_DESCRIPTION().
Add descriptions to the Cirrus EP93xx ethernet driver.
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://lore.kernel.org/r/20240123190332.677489-5-leitao@debian.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

W=1 builds now warn if module is built without a MODULE_DESCRIPTION().
Add descriptions to the Cavium Liquidio.
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://lore.kernel.org/r/20240123190332.677489-4-leitao@debian.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

W=1 builds now warn if module is built without a MODULE_DESCRIPTION().
Add descriptions to the Broadcom iProc GBit driver.
Signed-off-by: Breno Leitao <leitao@debian.org>
Acked-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://lore.kernel.org/r/20240123190332.677489-3-leitao@debian.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>