Merge tag 'v6.6.57' into for/openbmc/dev-6.6

This is the 6.6.57 stable release

net: do not delay dst_entries_add() in dst_release()

[ Upstream commit ac888d58869bb99753e7652be19a151df9ecb35d ]

dst_entries_add() uses per-cpu data that might be freed at netns
dismantle from ip6

net: do not delay dst_entries_add() in dst_release()

[ Upstream commit ac888d58869bb99753e7652be19a151df9ecb35d ]

dst_entries_add() uses per-cpu data that might be freed at netns
dismantle from ip6_route_net_exit() calling dst_entries_destroy()

Before ip6_route_net_exit() can be called, we release all
the dsts associated with this netns, via calls to dst_release(),
which waits an rcu grace period before calling dst_destroy()

dst_entries_add() use in dst_destroy() is racy, because
dst_entries_destroy() could have been called already.

Decrementing the number of dsts must happen sooner.

Notes:

1) in CONFIG_XFRM case, dst_destroy() can call
dst_release_immediate(child), this might also cause UAF
if the child does not have DST_NOCOUNT set.
IPSEC maintainers might take a look and see how to address this.

2) There is also discussion about removing this count of dst,
which might happen in future kernels.

Fixes: f88649721268 ("ipv4: fix dst race in sk_dst_get()")
Closes: https://lore.kernel.org/lkml/CANn89iLCCGsP7SFn9HKpvnKu96Td4KD08xf7aGtiYgZnkjaL=w@mail.gmail.com/T/
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Xin Long <lucien.xin@gmail.com>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Reviewed-by: Xin Long <lucien.xin@gmail.com>
Link: https://patch.msgid.link/20241008143110.1064899-1-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...

Merge drm/drm-fixes into drm-misc-fixes

Forwarding to v6.6-rc1.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>

Merge branch 'next' into for-linus

Prepare input updates for 6.6 merge window.

Merge tag 'net-next-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Pull networking updates from Paolo Abeni:
"Core:

- Increase size limits for to-be-sent skb frag allocat

Merge tag 'net-next-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Pull networking updates from Paolo Abeni:
"Core:

- Increase size limits for to-be-sent skb frag allocations. This
allows tun, tap devices and packet sockets to better cope with
large writes operations

- Store netdevs in an xarray, to simplify iterating over netdevs

- Refactor nexthop selection for multipath routes

- Improve sched class lifetime handling

- Add backup nexthop ID support for bridge

- Implement drop reasons support in openvswitch

- Several data races annotations and fixes

- Constify the sk parameter of routing functions

- Prepend kernel version to netconsole message

Protocols:

- Implement support for TCP probing the peer being under memory
pressure

- Remove hard coded limitation on IPv6 specific info placement inside
the socket struct

- Get rid of sysctl_tcp_adv_win_scale and use an auto-estimated per
socket scaling factor

- Scaling-up the IPv6 expired route GC via a separated list of
expiring routes

- In-kernel support for the TLS alert protocol

- Better support for UDP reuseport with connected sockets

- Add NEXT-C-SID support for SRv6 End.X behavior, reducing the SR
header size

- Get rid of additional ancillary per MPTCP connection struct socket

- Implement support for BPF-based MPTCP packet schedulers

- Format MPTCP subtests selftests results in TAP

- Several new SMC 2.1 features including unique experimental options,
max connections per lgr negotiation, max links per lgr negotiation

BPF:

- Multi-buffer support in AF_XDP

- Add multi uprobe BPF links for attaching multiple uprobes and usdt
probes, which is significantly faster and saves extra fds

- Implement an fd-based tc BPF attach API (TCX) and BPF link support
on top of it

- Add SO_REUSEPORT support for TC bpf_sk_assign

- Support new instructions from cpu v4 to simplify the generated code
and feature completeness, for x86, arm64, riscv64

- Support defragmenting IPv(4|6) packets in BPF

- Teach verifier actual bounds of bpf_get_smp_processor_id() and fix
perf+libbpf issue related to custom section handling

- Introduce bpf map element count and enable it for all program types

- Add a BPF hook in sys_socket() to change the protocol ID from
IPPROTO_TCP to IPPROTO_MPTCP to cover migration for legacy

- Introduce bpf_me_mcache_free_rcu() and fix OOM under stress

- Add uprobe support for the bpf_get_func_ip helper

- Check skb ownership against full socket

- Support for up to 12 arguments in BPF trampoline

- Extend link_info for kprobe_multi and perf_event links

Netfilter:

- Speed-up process exit by aborting ruleset validation if a fatal
signal is pending

- Allow NLA_POLICY_MASK to be used with BE16/BE32 types

Driver API:

- Page pool optimizations, to improve data locality and cache usage

- Introduce ndo_hwtstamp_get() and ndo_hwtstamp_set() to avoid the
need for raw ioctl() handling in drivers

- Simplify genetlink dump operations (doit/dumpit) providing them the
common information already populated in struct genl_info

- Extend and use the yaml devlink specs to [re]generate the split ops

- Introduce devlink selective dumps, to allow SF filtering SF based
on handle and other attributes

- Add yaml netlink spec for netlink-raw families, allow route, link
and address related queries via the ynl tool

- Remove phylink legacy mode support

- Support offload LED blinking to phy

- Add devlink port function attributes for IPsec

New hardware / drivers:

- Ethernet:
- Broadcom ASP 2.0 (72165) ethernet controller
- MediaTek MT7988 SoC
- Texas Instruments AM654 SoC
- Texas Instruments IEP driver
- Atheros qca8081 phy
- Marvell 88Q2110 phy
- NXP TJA1120 phy

- WiFi:
- MediaTek mt7981 support

- Can:
- Kvaser SmartFusion2 PCI Express devices
- Allwinner T113 controllers
- Texas Instruments tcan4552/4553 chips

- Bluetooth:
- Intel Gale Peak
- Qualcomm WCN3988 and WCN7850
- NXP AW693 and IW624
- Mediatek MT2925

Drivers:

- Ethernet NICs:
- nVidia/Mellanox:
- mlx5:
- support UDP encapsulation in packet offload mode
- IPsec packet offload support in eswitch mode
- improve aRFS observability by adding new set of counters
- extends MACsec offload support to cover RoCE traffic
- dynamic completion EQs
- mlx4:
- convert to use auxiliary bus instead of custom interface
logic
- Intel
- ice:
- implement switchdev bridge offload, even for LAG
interfaces
- implement SRIOV support for LAG interfaces
- igc:
- add support for multiple in-flight TX timestamps
- Broadcom:
- bnxt:
- use the unified RX page pool buffers for XDP and non-XDP
- use the NAPI skb allocation cache
- OcteonTX2:
- support Round Robin scheduling HTB offload
- TC flower offload support for SPI field
- Freescale:
- add XDP_TX feature support
- AMD:
- ionic: add support for PCI FLR event
- sfc:
- basic conntrack offload
- introduce eth, ipv4 and ipv6 pedit offloads
- ST Microelectronics:
- stmmac: maximze PTP timestamping resolution

- Virtual NICs:
- Microsoft vNIC:
- batch ringing RX queue doorbell on receiving packets
- add page pool for RX buffers
- Virtio vNIC:
- add per queue interrupt coalescing support
- Google vNIC:
- add queue-page-list mode support

- Ethernet high-speed switches:
- nVidia/Mellanox (mlxsw):
- add port range matching tc-flower offload
- permit enslavement to netdevices with uppers

- Ethernet embedded switches:
- Marvell (mv88e6xxx):
- convert to phylink_pcs
- Renesas:
- r8A779fx: add speed change support
- rzn1: enables vlan support

- Ethernet PHYs:
- convert mv88e6xxx to phylink_pcs

- WiFi:
- Qualcomm Wi-Fi 7 (ath12k):
- extremely High Throughput (EHT) PHY support
- RealTek (rtl8xxxu):
- enable AP mode for: RTL8192FU, RTL8710BU (RTL8188GU),
RTL8192EU and RTL8723BU
- RealTek (rtw89):
- Introduce Time Averaged SAR (TAS) support

- Connector:
- support for event filtering"

* tag 'net-next-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1806 commits)
net: ethernet: mtk_wed: minor change in wed_{tx,rx}info_show
net: ethernet: mtk_wed: add some more info in wed_txinfo_show handler
net: stmmac: clarify difference between "interface" and "phy_interface"
r8152: add vendor/device ID pair for D-Link DUB-E250
devlink: move devlink_notify_register/unregister() to dev.c
devlink: move small_ops definition into netlink.c
devlink: move tracepoint definitions into core.c
devlink: push linecard related code into separate file
devlink: push rate related code into separate file
devlink: push trap related code into separate file
devlink: use tracepoint_enabled() helper
devlink: push region related code into separate file
devlink: push param related code into separate file
devlink: push resource related code into separate file
devlink: push dpipe related code into separate file
devlink: move and rename devlink_dpipe_send_and_alloc_skb() helper
devlink: push shared buffer related code into separate file
devlink: push port related code into separate file
devlink: push object register/unregister notifications into separate helpers
inet: fix IP_TRANSPARENT error handling
...

show more ...

net: remove unnecessary input parameter 'how' in ifdown function

When the ifdown function in the dst_ops structure is referenced, the input
parameter 'how' is always true. In the current implementat

net: remove unnecessary input parameter 'how' in ifdown function

When the ifdown function in the dst_ops structure is referenced, the input
parameter 'how' is always true. In the current implementation of the
ifdown interface, ip6_dst_ifdown does not use the input parameter 'how',
xfrm6_dst_ifdown and xfrm4_dst_ifdown functions use the input parameter
'unregister'. But false judgment on 'unregister' in xfrm6_dst_ifdown and
xfrm4_dst_ifdown is false, so remove the input parameter 'how' in ifdown
function.

Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20230821084104.3812233-1-shaozhengchao@huawei.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

show more ...

Merge tag 'v6.4' into next

Sync up with mainline to bring in updates to shared infrastructure.

Merge drm/drm-next into drm-misc-next-fixes

Backmerging to sync drm-misc-next-fixes with drm-misc-next.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>

Merge branch 'drm-next' of git://anongit.freedesktop.org/drm/drm into msm-next-lumag-base

Merge the drm-next tree to pick up the DRM DSC helpers (merged via
drm-intel-next tree). MSM DSC v1.2 patche

Merge branch 'drm-next' of git://anongit.freedesktop.org/drm/drm into msm-next-lumag-base

Merge the drm-next tree to pick up the DRM DSC helpers (merged via
drm-intel-next tree). MSM DSC v1.2 patches depend on these helpers.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

show more ...

Merge tag 'v6.4-rc4' into wpan-next/staging

Linux 6.4-rc4

Merge drm/drm-next into drm-intel-gt-next

For conflict avoidance we need the following commit:

c9a9f18d3ad8 drm/i915/huc: use const struct bus_type pointers

Signed-off-by: Tvrtko Ursulin <tvrtko

Merge drm/drm-next into drm-intel-gt-next

For conflict avoidance we need the following commit:

c9a9f18d3ad8 drm/i915/huc: use const struct bus_type pointers

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

show more ...

Merge drm/drm-next into drm-intel-next

Backmerge to get some hwmon dependencies.

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

Merge drm/drm-fixes into drm-misc-fixes

Let's bring 6.4-rc1 in drm-misc-fixes to start the new fix cycle.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>

Merge drm/drm-next into drm-misc-next

Start the 6.5 release cycle.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>

Merge branch 'next' into for-linus

Prepare input updates for 6.4 merge window.

Merge tag 'net-next-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Pull networking updates from Paolo Abeni:
"Core:

- Introduce a config option to tweak MAX_SKB_FRAGS. In

Merge tag 'net-next-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Pull networking updates from Paolo Abeni:
"Core:

- Introduce a config option to tweak MAX_SKB_FRAGS. Increasing the
default value allows for better BIG TCP performances

- Reduce compound page head access for zero-copy data transfers

- RPS/RFS improvements, avoiding unneeded NET_RX_SOFTIRQ when
possible

- Threaded NAPI improvements, adding defer skb free support and
unneeded softirq avoidance

- Address dst_entry reference count scalability issues, via false
sharing avoidance and optimize refcount tracking

- Add lockless accesses annotation to sk_err[_soft]

- Optimize again the skb struct layout

- Extends the skb drop reasons to make it usable by multiple
subsystems

- Better const qualifier awareness for socket casts

BPF:

- Add skb and XDP typed dynptrs which allow BPF programs for more
ergonomic and less brittle iteration through data and
variable-sized accesses

- Add a new BPF netfilter program type and minimal support to hook
BPF programs to netfilter hooks such as prerouting or forward

- Add more precise memory usage reporting for all BPF map types

- Adds support for using {FOU,GUE} encap with an ipip device
operating in collect_md mode and add a set of BPF kfuncs for
controlling encap params

- Allow BPF programs to detect at load time whether a particular
kfunc exists or not, and also add support for this in light
skeleton

- Bigger batch of BPF verifier improvements to prepare for upcoming
BPF open-coded iterators allowing for less restrictive looping
capabilities

- Rework RCU enforcement in the verifier, add kptr_rcu and enforce
BPF programs to NULL-check before passing such pointers into kfunc

- Add support for kptrs in percpu hashmaps, percpu LRU hashmaps and
in local storage maps

- Enable RCU semantics for task BPF kptrs and allow referenced kptr
tasks to be stored in BPF maps

- Add support for refcounted local kptrs to the verifier for allowing
shared ownership, useful for adding a node to both the BPF list and
rbtree

- Add BPF verifier support for ST instructions in
convert_ctx_access() which will help new -mcpu=v4 clang flag to
start emitting them

- Add ARM32 USDT support to libbpf

- Improve bpftool's visual program dump which produces the control
flow graph in a DOT format by adding C source inline annotations

Protocols:

- IPv4: Allow adding to IPv4 address a 'protocol' tag. Such value
indicates the provenance of the IP address

- IPv6: optimize route lookup, dropping unneeded R/W lock acquisition

- Add the handshake upcall mechanism, allowing the user-space to
implement generic TLS handshake on kernel's behalf

- Bridge: support per-{Port, VLAN} neighbor suppression, increasing
resilience to nodes failures

- SCTP: add support for Fair Capacity and Weighted Fair Queueing
schedulers

- MPTCP: delay first subflow allocation up to its first usage. This
will allow for later better LSM interaction

- xfrm: Remove inner/outer modes from input/output path. These are
not needed anymore

- WiFi:
- reduced neighbor report (RNR) handling for AP mode
- HW timestamping support
- support for randomized auth/deauth TA for PASN privacy
- per-link debugfs for multi-link
- TC offload support for mac80211 drivers
- mac80211 mesh fast-xmit and fast-rx support
- enable Wi-Fi 7 (EHT) mesh support

Netfilter:

- Add nf_tables 'brouting' support, to force a packet to be routed
instead of being bridged

- Update bridge netfilter and ovs conntrack helpers to handle IPv6
Jumbo packets properly, i.e. fetch the packet length from
hop-by-hop extension header. This is needed for BIT TCP support

- The iptables 32bit compat interface isn't compiled in by default
anymore

- Move ip(6)tables builtin icmp matches to the udptcp one. This has
the advantage that icmp/icmpv6 match doesn't load the
iptables/ip6tables modules anymore when iptables-nft is used

- Extended netlink error report for netdevice in flowtables and
netdev/chains. Allow for incrementally add/delete devices to netdev
basechain. Allow to create netdev chain without device

Driver API:

- Remove redundant Device Control Error Reporting Enable, as PCI core
has already error reporting enabled at enumeration time

- Move Multicast DB netlink handlers to core, allowing devices other
then bridge to use them

- Allow the page_pool to directly recycle the pages from safely
localized NAPI

- Implement lockless TX queue stop/wake combo macros, allowing for
further code de-duplication and sanitization

- Add YNL support for user headers and struct attrs

- Add partial YNL specification for devlink

- Add partial YNL specification for ethtool

- Add tc-mqprio and tc-taprio support for preemptible traffic classes

- Add tx push buf len param to ethtool, specifies the maximum number
of bytes of a transmitted packet a driver can push directly to the
underlying device

- Add basic LED support for switch/phy

- Add NAPI documentation, stop relaying on external links

- Convert dsa_master_ioctl() to netdev notifier. This is a
preparatory work to make the hardware timestamping layer selectable
by user space

- Add transceiver support and improve the error messages for CAN-FD
controllers

New hardware / drivers:

- Ethernet:
- AMD/Pensando core device support
- MediaTek MT7981 SoC
- MediaTek MT7988 SoC
- Broadcom BCM53134 embedded switch
- Texas Instruments CPSW9G ethernet switch
- Qualcomm EMAC3 DWMAC ethernet
- StarFive JH7110 SoC
- NXP CBTX ethernet PHY

- WiFi:
- Apple M1 Pro/Max devices
- RealTek rtl8710bu/rtl8188gu
- RealTek rtl8822bs, rtl8822cs and rtl8821cs SDIO chipset

- Bluetooth:
- Realtek RTL8821CS, RTL8851B, RTL8852BS
- Mediatek MT7663, MT7922
- NXP w8997
- Actions Semi ATS2851
- QTI WCN6855
- Marvell 88W8997

- Can:
- STMicroelectronics bxcan stm32f429

Drivers:

- Ethernet NICs:
- Intel (1G, icg):
- add tracking and reporting of QBV config errors
- add support for configuring max SDU for each Tx queue
- Intel (100G, ice):
- refactor mailbox overflow detection to support Scalable IOV
- GNSS interface optimization
- Intel (i40e):
- support XDP multi-buffer
- nVidia/Mellanox:
- add the support for linux bridge multicast offload
- enable TC offload for egress and engress MACVLAN over bond
- add support for VxLAN GBP encap/decap flows offload
- extend packet offload to fully support libreswan
- support tunnel mode in mlx5 IPsec packet offload
- extend XDP multi-buffer support
- support MACsec VLAN offload
- add support for dynamic msix vectors allocation
- drop RX page_cache and fully use page_pool
- implement thermal zone to report NIC temperature
- Netronome/Corigine:
- add support for multi-zone conntrack offload
- Solarflare/Xilinx:
- support offloading TC VLAN push/pop actions to the MAE
- support TC decap rules
- support unicast PTP

- Other NICs:
- Broadcom (bnxt): enforce software based freq adjustments only on
shared PHC NIC
- RealTek (r8169): refactor to addess ASPM issues during NAPI poll
- Micrel (lan8841): add support for PTP_PF_PEROUT
- Cadence (macb): enable PTP unicast
- Engleder (tsnep): add XDP socket zero-copy support
- virtio-net: implement exact header length guest feature
- veth: add page_pool support for page recycling
- vxlan: add MDB data path support
- gve: add XDP support for GQI-QPL format
- geneve: accept every ethertype
- macvlan: allow some packets to bypass broadcast queue
- mana: add support for jumbo frame

- Ethernet high-speed switches:
- Microchip (sparx5): Add support for TC flower templates

- Ethernet embedded switches:
- Broadcom (b54):
- configure 6318 and 63268 RGMII ports
- Marvell (mv88e6xxx):
- faster C45 bus scan
- Microchip:
- lan966x:
- add support for IS1 VCAP
- better TX/RX from/to CPU performances
- ksz9477: add ETS Qdisc support
- ksz8: enhance static MAC table operations and error handling
- sama7g5: add PTP capability
- NXP (ocelot):
- add support for external ports
- add support for preemptible traffic classes
- Texas Instruments:
- add CPSWxG SGMII support for J7200 and J721E

- Intel WiFi (iwlwifi):
- preparation for Wi-Fi 7 EHT and multi-link support
- EHT (Wi-Fi 7) sniffer support
- hardware timestamping support for some devices/firwmares
- TX beacon protection on newer hardware

- Qualcomm 802.11ax WiFi (ath11k):
- MU-MIMO parameters support
- ack signal support for management packets

- RealTek WiFi (rtw88):
- SDIO bus support
- better support for some SDIO devices (e.g. MAC address from
efuse)

- RealTek WiFi (rtw89):
- HW scan support for 8852b
- better support for 6 GHz scanning
- support for various newer firmware APIs
- framework firmware backwards compatibility

- MediaTek WiFi (mt76):
- P2P support
- mesh A-MSDU support
- EHT (Wi-Fi 7) support
- coredump support"

* tag 'net-next-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2078 commits)
net: phy: hide the PHYLIB_LEDS knob
net: phy: marvell-88x2222: remove unnecessary (void*) conversions
tcp/udp: Fix memleaks of sk and zerocopy skbs with TX timestamp.
net: amd: Fix link leak when verifying config failed
net: phy: marvell: Fix inconsistent indenting in led_blink_set
lan966x: Don't use xdp_frame when action is XDP_TX
tsnep: Add XDP socket zero-copy TX support
tsnep: Add XDP socket zero-copy RX support
tsnep: Move skb receive action to separate function
tsnep: Add functions for queue enable/disable
tsnep: Rework TX/RX queue initialization
tsnep: Replace modulo operation with mask
net: phy: dp83867: Add led_brightness_set support
net: phy: Fix reading LED reg property
drivers: nfc: nfcsim: remove return value check of `dev_dir`
net: phy: dp83867: Remove unnecessary (void*) conversions
net: ethtool: coalesce: try to make user settings stick twice
net: mana: Check if netdev/napi_alloc_frag returns single page
net: mana: Rename mana_refill_rxoob and remove some empty lines
net: veth: add page_pool stats
...

show more ...

net: dst: fix missing initialization of rt_uncached

xfrm_alloc_dst() followed by xfrm4_dst_destroy(), without a
xfrm4_fill_dst() call in between, causes the following BUG:

BUG: spinlock bad magic

net: dst: fix missing initialization of rt_uncached

xfrm_alloc_dst() followed by xfrm4_dst_destroy(), without a
xfrm4_fill_dst() call in between, causes the following BUG:

BUG: spinlock bad magic on CPU#0, fbxhostapd/732
lock: 0x890b7668, .magic: 890b7668, .owner: <none>/-1, .owner_cpu: 0
CPU: 0 PID: 732 Comm: fbxhostapd Not tainted 6.3.0-rc6-next-20230414-00613-ge8de66369925-dirty #9
Hardware name: Marvell Kirkwood (Flattened Device Tree)
unwind_backtrace from show_stack+0x10/0x14
show_stack from dump_stack_lvl+0x28/0x30
dump_stack_lvl from do_raw_spin_lock+0x20/0x80
do_raw_spin_lock from rt_del_uncached_list+0x30/0x64
rt_del_uncached_list from xfrm4_dst_destroy+0x3c/0xbc
xfrm4_dst_destroy from dst_destroy+0x5c/0xb0
dst_destroy from rcu_process_callbacks+0xc4/0xec
rcu_process_callbacks from __do_softirq+0xb4/0x22c
__do_softirq from call_with_stack+0x1c/0x24
call_with_stack from do_softirq+0x60/0x6c
do_softirq from __local_bh_enable_ip+0xa0/0xcc

Patch "net: dst: Prevent false sharing vs. dst_entry:: __refcnt" moved
rt_uncached and rt_uncached_list fields from rtable struct to dst
struct, so they are more zeroed by memset_after(xdst, 0, u.dst) in
xfrm_alloc_dst().

Note that rt_uncached (list_head) was never properly initialized at
alloc time, but xfrm[46]_dst_destroy() is written in such a way that
it was not an issue thanks to the memset:

if (xdst->u.rt.dst.rt_uncached_list)
rt_del_uncached_list(&xdst->u.rt);

The route code does it the other way around: rt_uncached_list is
assumed to be valid IIF rt_uncached list_head is not empty:

void rt_del_uncached_list(struct rtable *rt)
{
if (!list_empty(&rt->dst.rt_uncached)) {
struct uncached_list *ul = rt->dst.rt_uncached_list;

spin_lock_bh(&ul->lock);
list_del_init(&rt->dst.rt_uncached);
spin_unlock_bh(&ul->lock);
}
}

This patch adds mandatory rt_uncached list_head initialization in
generic dst_init(), and adapt xfrm[46]_dst_destroy logic to match the
rest of the code.

Fixes: d288a162dd1c ("net: dst: Prevent false sharing vs. dst_entry:: __refcnt")
Reported-by: kernel test robot <oliver.sang@intel.com>
Link: https://lore.kernel.org/oe-lkp/202304162125.18b7bcdd-oliver.sang@intel.com
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
CC: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Maxime Bizon <mbizon@freebox.fr>
Link: https://lore.kernel.org/r/20230420182508.2417582-1-mbizon@freebox.fr
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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Merge drm/drm-next into drm-intel-gt-next

Need to pull in commit from drm-next (earlier in drm-intel-next):

1eca0778f4b3 ("drm/i915: add struct i915_dsm to wrap dsm members together")

In order to

Merge drm/drm-next into drm-intel-gt-next

Need to pull in commit from drm-next (earlier in drm-intel-next):

1eca0778f4b3 ("drm/i915: add struct i915_dsm to wrap dsm members together")

In order to merge following patch to drm-intel-gt-next:

https://patchwork.freedesktop.org/patch/530942/?series=114925&rev=6

Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

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Merge branch 'net-refcount-address-dst_entry-reference-count-scalability-issues'

Thomas Gleixner says:

====================
net, refcount: Address dst_entry reference count scalability issues

This

Merge branch 'net-refcount-address-dst_entry-reference-count-scalability-issues'

Thomas Gleixner says:

====================
net, refcount: Address dst_entry reference count scalability issues

This is version 3 of this series. Version 2 can be found here:

https://lore.kernel.org/lkml/20230307125358.772287565@linutronix.de

Wangyang and Arjan reported a bottleneck in the networking code related to
struct dst_entry::__refcnt. Performance tanks massively when concurrency on
a dst_entry increases.

This happens when there are a large amount of connections to or from the
same IP address. The memtier benchmark when run on the same host as
memcached amplifies this massively. But even over real network connections
this issue can be observed at an obviously smaller scale (due to the
network bandwith limitations in my setup, i.e. 1Gb). How to reproduce:

Run memcached with -t $N and memtier_benchmark with -t $M and --ratio=1:100
on the same machine. localhost connections amplify the problem.

Start with the defaults for $N and $M and increase them. Depending on
your machine this will tank at some point. But even in reasonably small
$N, $M scenarios the refcount operations and the resulting false sharing
fallout becomes visible in perf top. At some point it becomes the
dominating issue.

There are two factors which make this reference count a scalability issue:

1) False sharing

dst_entry:__refcnt is located at offset 64 of dst_entry, which puts
it into a seperate cacheline vs. the read mostly members located at
the beginning of the struct.

That prevents false sharing vs. the struct members in the first 64
bytes of the structure, but there is also

dst_entry::lwtstate

which is located after the reference count and in the same cache
line. This member is read after a reference count has been acquired.

The other problem is struct rtable, which embeds a struct dst_entry
at offset 0. struct dst_entry has a size of 112 bytes, which means
that the struct members of rtable which follow the dst member share
the same cache line as dst_entry::__refcnt. Especially

rtable::rt_genid

is also read by the contexts which have a reference count acquired
already.

When dst_entry:__refcnt is incremented or decremented via an atomic
operation these read accesses stall and contribute to the performance
problem.

2) atomic_inc_not_zero()

A reference on dst_entry:__refcnt is acquired via
atomic_inc_not_zero() and released via atomic_dec_return().

atomic_inc_not_zero() is implemted via a atomic_try_cmpxchg() loop,
which exposes O(N^2) behaviour under contention with N concurrent
operations. Contention scalability is degrading with even a small
amount of contenders and gets worse from there.

Lightweight instrumentation exposed an average of 8!! retry loops per
atomic_inc_not_zero() invocation in a inc()/dec() loop running
concurrently on 112 CPUs.

There is nothing which can be done to make atomic_inc_not_zero() more
scalable.

The following series addresses these issues:

1) Reorder and pad struct dst_entry to prevent the false sharing.

2) Implement and use a reference count implementation which avoids the
atomic_inc_not_zero() problem.

It is slightly less performant in the case of the final 0 -> -1
transition, but the deconstruction of these objects is a low
frequency event. get()/put() pairs are in the hotpath and that's
what this implementation optimizes for.

The algorithm of this reference count is only suitable for RCU
managed objects. Therefore it cannot replace the refcount_t
algorithm, which is also based on atomic_inc_not_zero(), due to a
subtle race condition related to the 0 -> -1 transition and the final
verdict to mark the reference count dead. See details in patch 2/3.

It might be just my lack of imagination which declares this to be
impossible and I'd be happy to be proven wrong.

As a bonus the new rcuref implementation provides underflow/overflow
detection and mitigation while being performance wise on par with
open coded atomic_inc_not_zero() / atomic_dec_return() pairs even in
the non-contended case.

The combination of these two changes results in performance gains in micro
benchmarks and also localhost and networked memtier benchmarks talking to
memcached. It's hard to quantify the benchmark results as they depend
heavily on the micro-architecture and the number of concurrent operations.

The overall gain of both changes for localhost memtier ranges from 1.2X to
3.2X and from +2% to %5% range for networked operations on a 1Gb connection.

A micro benchmark which enforces maximized concurrency shows a gain between
1.2X and 4.7X!!!

Obviously this is focussed on a particular problem and therefore needs to
be discussed in detail. It also requires wider testing outside of the cases
which this is focussed on.

Though the false sharing issue is obvious and should be addressed
independent of the more focussed reference count changes.

The series is also available from git:

git://git.kernel.org/pub/scm/linux/kernel/git/tglx/devel.git rcuref

Changes vs. V2:

- Rename __refcnt to __rcuref (Linus)

- Fix comments and changelogs (Mark, Qiuxu)

- Fixup kernel doc of generated atomic_add_negative() variants

I want to say thanks to Wangyang who analyzed the issue and provided the
initial fix for the false sharing problem. Further thanks go to Arjan
Peter, Marc, Will and Borislav for valuable input and providing test
results on machines which I do not have access to, and to Linus and
Eric, Qiuxu and Mark for helpful feedback.
====================

Link: https://lore.kernel.org/r/20230323102649.764958589@linutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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net: dst: Switch to rcuref_t reference counting

Under high contention dst_entry::__refcnt becomes a significant bottleneck.

atomic_inc_not_zero() is implemented with a cmpxchg() loop, which goes in

net: dst: Switch to rcuref_t reference counting

Under high contention dst_entry::__refcnt becomes a significant bottleneck.

atomic_inc_not_zero() is implemented with a cmpxchg() loop, which goes into
high retry rates on contention.

Switch the reference count to rcuref_t which results in a significant
performance gain. Rename the reference count member to __rcuref to reflect
the change.

The gain depends on the micro-architecture and the number of concurrent
operations and has been measured in the range of +25% to +130% with a
localhost memtier/memcached benchmark which amplifies the problem
massively.

Running the memtier/memcached benchmark over a real (1Gb) network
connection the conversion on top of the false sharing fix for struct
dst_entry::__refcnt results in a total gain in the 2%-5% range over the
upstream baseline.

Reported-by: Wangyang Guo <wangyang.guo@intel.com>
Reported-by: Arjan Van De Ven <arjan.van.de.ven@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230307125538.989175656@linutronix.de
Link: https://lore.kernel.org/r/20230323102800.215027837@linutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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Merge drm/drm-next into drm-intel-next

Catch up with 6.3-rc cycle...

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

Merge remote-tracking branch 'drm/drm-next' into msm-next

Merge drm-next into msm-next to pick up external clk and PM dependencies
for improved a6xx GPU reset sequence.

Signed-off-by: Rob Clark <ro

Merge remote-tracking branch 'drm/drm-next' into msm-next

Merge drm-next into msm-next to pick up external clk and PM dependencies
for improved a6xx GPU reset sequence.

Signed-off-by: Rob Clark <robdclark@chromium.org>

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Merge tag 'v6.3-rc2' into next

Merge with mainline to get of_property_present() and other newer APIs.

Merge drm/drm-fixes into drm-misc-fixes

Backmerging to get latest upstream.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>

Merge drm/drm-next into drm-misc-next

Backmerging to get v6.3-rc1 and sync with the other DRM trees.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>