kernel/git/stable/linux-stable.git/include/net/xdp.h, branch linux-6.17.y

bpf: Clear pfmemalloc flag when freeing all fragments

2025-11-13T20:36:53+00:00

[ Upstream commit 8f12d1137c2382c80aada8e05d7cc650cd4e403c ] It is possible for bpf_xdp_adjust_tail() to free all fragments. The kfunc currently clears the XDP_FLAGS_HAS_FRAGS bit, but not XDP_FLAGS_FRAGS_PF_MEMALLOC. So far, this has not caused a issue when building sk_buff from xdp_buff since all readers of xdp_buff->flags use the flag only when there are fragments. Clear the XDP_FLAGS_FRAGS_PF_MEMALLOC bit as well to make the flags correct. Signed-off-by: Amery Hung Signed-off-by: Martin KaFai Lau Reviewed-by: Maciej Fijalkowski Link: https://patch.msgid.link/20250922233356.3356453-2-ameryhung@gmail.com Signed-off-by: Sasha Levin

xdp: create locked/unlocked instances of xdp redirect target setters

2025-04-23T02:57:56+00:00

Commit 03df156dd3a6 ("xdp: double protect netdev->xdp_flags with netdev->lock") introduces the netdev lock to xdp_set_features_flag(). The change includes a _locked version of the method, as it is possible for a driver to have already acquired the netdev lock before calling this helper. However, the same applies to xdp_features_(set|clear)_redirect_flags(), which ends up calling the unlocked version of xdp_set_features_flags() leading to deadlocks in GVE, which grabs the netdev lock as part of its suspend, reset, and shutdown processes: [ 833.265543] WARNING: possible recursive locking detected [ 833.270949] 6.15.0-rc1 #6 Tainted: G E [ 833.276271] -------------------------------------------- [ 833.281681] systemd-shutdow/1 is trying to acquire lock: [ 833.287090] ffff949d2b148c68 (&dev->lock){+.+.}-{4:4}, at: xdp_set_features_flag+0x29/0x90 [ 833.295470] [ 833.295470] but task is already holding lock: [ 833.301400] ffff949d2b148c68 (&dev->lock){+.+.}-{4:4}, at: gve_shutdown+0x44/0x90 [gve] [ 833.309508] [ 833.309508] other info that might help us debug this: [ 833.316130] Possible unsafe locking scenario: [ 833.316130] [ 833.322142] CPU0 [ 833.324681] ---- [ 833.327220] lock(&dev->lock); [ 833.330455] lock(&dev->lock); [ 833.333689] [ 833.333689] *** DEADLOCK *** [ 833.333689] [ 833.339701] May be due to missing lock nesting notation [ 833.339701] [ 833.346582] 5 locks held by systemd-shutdow/1: [ 833.351205] #0: ffffffffa9c89130 (system_transition_mutex){+.+.}-{4:4}, at: __se_sys_reboot+0xe6/0x210 [ 833.360695] #1: ffff93b399e5c1b8 (&dev->mutex){....}-{4:4}, at: device_shutdown+0xb4/0x1f0 [ 833.369144] #2: ffff949d19a471b8 (&dev->mutex){....}-{4:4}, at: device_shutdown+0xc2/0x1f0 [ 833.377603] #3: ffffffffa9eca050 (rtnl_mutex){+.+.}-{4:4}, at: gve_shutdown+0x33/0x90 [gve] [ 833.386138] #4: ffff949d2b148c68 (&dev->lock){+.+.}-{4:4}, at: gve_shutdown+0x44/0x90 [gve] Introduce xdp_features_(set|clear)_redirect_target_locked() versions which assume that the netdev lock has already been acquired before setting the XDP feature flag and update GVE to use the locked version. Fixes: 03df156dd3a6 ("xdp: double protect netdev->xdp_flags with netdev->lock") Tested-by: Mina Almasry Reviewed-by: Willem de Bruijn Reviewed-by: Harshitha Ramamurthy Signed-off-by: Joshua Washington Acked-by: Stanislav Fomichev Acked-by: Martin KaFai Lau Link: https://patch.msgid.link/20250422011643.3509287-1-joshwash@google.com Signed-off-by: Jakub Kicinski

xdp: double protect netdev->xdp_flags with netdev->lock

2025-04-10T00:01:52+00:00

Protect xdp_features with netdev->lock. This way pure readers no longer have to take rtnl_lock to access the field. This includes calling NETDEV_XDP_FEAT_CHANGE under the lock. Looks like that's fine for bonding, the only "real" listener, it's the same as ethtool feature change. In terms of normal drivers - only GVE need special consideration (other drivers don't use instance lock or don't support XDP). It calls xdp_set_features_flag() helper from gve_init_priv() which in turn is called from gve_reset_recovery() (locked), or prior to netdev registration. So switch to _locked. Reviewed-by: Joe Damato Acked-by: Stanislav Fomichev Acked-by: Harshitha Ramamurthy Acked-by: Martin KaFai Lau Link: https://patch.msgid.link/20250408195956.412733-6-kuba@kernel.org Signed-off-by: Jakub Kicinski

xdp: remove xdp_alloc_skb_bulk()

2025-02-27T13:03:52+00:00

The only user was veth, which now uses napi_skb_cache_get_bulk(). It's now preferred over a direct allocation and is exported as well, so remove this one. Reviewed-by: Toke Høiland-Jørgensen Signed-off-by: Alexander Lobakin Signed-off-by: Paolo Abeni

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2025-01-16T18:34:59+00:00

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

xsk: Bring back busy polling support

2025-01-11T02:07:56+00:00

Commit 86e25f40aa1e ("net: napi: Add napi_config") moved napi->napi_id assignment to a later point in time (napi_hash_add_with_id). This breaks __xdp_rxq_info_reg which copies napi_id at an earlier time and now stores 0 napi_id. It also makes sk_mark_napi_id_once_xdp and __sk_mark_napi_id_once useless because they now work against 0 napi_id. Since sk_busy_loop requires valid napi_id to busy-poll on, there is no way to busy-poll AF_XDP sockets anymore. Bring back the ability to busy-poll on XSK by resolving socket's napi_id at bind time. This relies on relatively recent netif_queue_set_napi, but (assume) at this point most popular drivers should have been converted. This also removes per-tx/rx cycles which used to check and/or set the napi_id value. Confirmed by running a busy-polling AF_XDP socket (github.com/fomichev/xskrtt) on mlx5 and looking at BusyPollRxPackets from /proc/net/netstat. Fixes: 86e25f40aa1e ("net: napi: Add napi_config") Signed-off-by: Stanislav Fomichev Acked-by: Magnus Karlsson Reviewed-by: Jakub Kicinski Link: https://patch.msgid.link/20250109003436.2829560-1-sdf@fomichev.me Signed-off-by: Jakub Kicinski

xsk: add generic XSk &xdp_buff -> skb conversion

2024-12-20T03:51:14+00:00

Same as with converting &xdp_buff to skb on Rx, the code which allocates a new skb and copies the XSk frame there is identical across the drivers, so make it generic. This includes copying all the frags if they are present in the original buff. System percpu page_pools greatly improve XDP_PASS performance on XSk: instead of page_alloc() + page_free(), the net core recycles the same pages, so the only overhead left is memcpy()s. When the Page Pool is not compiled in, the whole function is a return-NULL (but it always gets selected when eBPF is enabled). Note that the passed buff gets freed if the conversion is done w/o any error, assuming you don't need this buffer after you convert it to an skb. Reviewed-by: Maciej Fijalkowski Signed-off-by: Alexander Lobakin Link: https://patch.msgid.link/20241218174435.1445282-6-aleksander.lobakin@intel.com Signed-off-by: Jakub Kicinski

xdp: add generic xdp_build_skb_from_buff()

2024-12-20T03:51:14+00:00

The code which builds an skb from an &xdp_buff keeps multiplying itself around the drivers with almost no changes. Let's try to stop that by adding a generic function. Unlike __xdp_build_skb_from_frame(), always allocate an skbuff head using napi_build_skb() and make use of the available xdp_rxq pointer to assign the Rx queue index. In case of PP-backed buffer, mark the skb to be recycled, as every PP user's been switched to recycle skbs. Reviewed-by: Toke Høiland-Jørgensen Signed-off-by: Alexander Lobakin Link: https://patch.msgid.link/20241218174435.1445282-4-aleksander.lobakin@intel.com Signed-off-by: Jakub Kicinski

xdp: add generic xdp_buff_add_frag()

2024-12-20T03:51:13+00:00

The code piece which would attach a frag to &xdp_buff is almost identical across the drivers supporting XDP multi-buffer on Rx. Make it a generic elegant "oneliner". Also, I see lots of drivers calculating frags_truesize as `xdp->frame_sz * nr_frags`. I can't say this is fully correct, since frags might be backed by chunks of different sizes, especially with stuff like the header split. Even page_pool_alloc() can give you two different truesizes on two subsequent requests to allocate the same buffer size. Add a field to &skb_shared_info (unionized as there's no free slot currently on x86_64) to track the "true" truesize. It can be used later when updating the skb. Reviewed-by: Maciej Fijalkowski Signed-off-by: Alexander Lobakin Link: https://patch.msgid.link/20241218174435.1445282-3-aleksander.lobakin@intel.com Signed-off-by: Jakub Kicinski

xdp: make __xdp_return() MP-agnostic

2024-12-13T02:22:52+00:00

Currently, __xdp_return() takes pointer to the virtual memory to free a buffer. Apart from that this sometimes provokes redundant data <--> page conversions, taking data pointer effectively prevents lots of XDP code to support non-page-backed buffers, as there's no mapping for the non-host memory (data is always NULL). Just convert it to always take netmem reference. For xdp_return_{buff,frame*}(), this chops off one page_address() per each frag and adds one virt_to_netmem() (same as virt_to_page()) per header buffer. For __xdp_return() itself, it removes one virt_to_page() for MEM_TYPE_PAGE_POOL and another one for MEM_TYPE_PAGE_ORDER0, adding one page_address() for [not really common nowadays] MEM_TYPE_PAGE_SHARED, but the main effect is that the abovementioned functions won't die or memleak anymore if the frame has non-host memory attached and will correctly free those. Signed-off-by: Alexander Lobakin Link: https://patch.msgid.link/20241211172649.761483-4-aleksander.lobakin@intel.com Signed-off-by: Jakub Kicinski