kernel/net/core/xdp.c, branch linux-5.1.y

xdp: remove redundant variable 'headroom'

2018-08-31T23:35:53Z

Variable 'headroom' is being assigned but is never used hence it is redundant and can be removed. Cleans up clang warning: variable ‘headroom’ set but not used [-Wunused-but-set-variable] Signed-off-by: Colin Ian King Acked-by: Björn Töpel Signed-off-by: Alexei Starovoitov Signed-off-by: Daniel Borkmann

xdp: export xdp_rxq_info_unreg_mem_model

2018-08-29T19:25:53Z

Export __xdp_rxq_info_unreg_mem_model as xdp_rxq_info_unreg_mem_model, so it can be used from netdev drivers. Also, add additional checks for the memory type. Signed-off-by: Björn Töpel Signed-off-by: Alexei Starovoitov

xdp: implement convert_to_xdp_frame for MEM_TYPE_ZERO_COPY

2018-08-29T19:25:53Z

This commit adds proper MEM_TYPE_ZERO_COPY support for convert_to_xdp_frame. Converting a MEM_TYPE_ZERO_COPY xdp_buff to an xdp_frame is done by transforming the MEM_TYPE_ZERO_COPY buffer into a MEM_TYPE_PAGE_ORDER0 frame. This is costly, and in the future it might make sense to implement a more sophisticated thread-safe alloc/free scheme for MEM_TYPE_ZERO_COPY, so that no allocation and copy is required in the fast-path. Signed-off-by: Björn Töpel Signed-off-by: Alexei Starovoitov

net/xdp: Fix suspicious RCU usage warning

2018-08-16T19:55:21Z

Fix the warning below by calling rhashtable_lookup_fast. Also, make some code movements for better quality and human readability. [ 342.450870] WARNING: suspicious RCU usage [ 342.455856] 4.18.0-rc2+ #17 Tainted: G O [ 342.462210] ----------------------------- [ 342.467202] ./include/linux/rhashtable.h:481 suspicious rcu_dereference_check() usage! [ 342.476568] [ 342.476568] other info that might help us debug this: [ 342.476568] [ 342.486978] [ 342.486978] rcu_scheduler_active = 2, debug_locks = 1 [ 342.495211] 4 locks held by modprobe/3934: [ 342.500265] #0: 00000000e23116b2 (mlx5_intf_mutex){+.+.}, at: mlx5_unregister_interface+0x18/0x90 [mlx5_core] [ 342.511953] #1: 00000000ca16db96 (rtnl_mutex){+.+.}, at: unregister_netdev+0xe/0x20 [ 342.521109] #2: 00000000a46e2c4b (&priv->state_lock){+.+.}, at: mlx5e_close+0x29/0x60 [mlx5_core] [ 342.531642] #3: 0000000060c5bde3 (mem_id_lock){+.+.}, at: xdp_rxq_info_unreg+0x93/0x6b0 [ 342.541206] [ 342.541206] stack backtrace: [ 342.547075] CPU: 12 PID: 3934 Comm: modprobe Tainted: G O 4.18.0-rc2+ #17 [ 342.556621] Hardware name: Dell Inc. PowerEdge R730/0H21J3, BIOS 1.5.4 10/002/2015 [ 342.565606] Call Trace: [ 342.568861] dump_stack+0x78/0xb3 [ 342.573086] xdp_rxq_info_unreg+0x3f5/0x6b0 [ 342.578285] ? __call_rcu+0x220/0x300 [ 342.582911] mlx5e_free_rq+0x38/0xc0 [mlx5_core] [ 342.588602] mlx5e_close_channel+0x20/0x120 [mlx5_core] [ 342.594976] mlx5e_close_channels+0x26/0x40 [mlx5_core] [ 342.601345] mlx5e_close_locked+0x44/0x50 [mlx5_core] [ 342.607519] mlx5e_close+0x42/0x60 [mlx5_core] [ 342.613005] __dev_close_many+0xb1/0x120 [ 342.617911] dev_close_many+0xa2/0x170 [ 342.622622] rollback_registered_many+0x148/0x460 [ 342.628401] ? __lock_acquire+0x48d/0x11b0 [ 342.633498] ? unregister_netdev+0xe/0x20 [ 342.638495] rollback_registered+0x56/0x90 [ 342.643588] unregister_netdevice_queue+0x7e/0x100 [ 342.649461] unregister_netdev+0x18/0x20 [ 342.654362] mlx5e_remove+0x2a/0x50 [mlx5_core] [ 342.659944] mlx5_remove_device+0xe5/0x110 [mlx5_core] [ 342.666208] mlx5_unregister_interface+0x39/0x90 [mlx5_core] [ 342.673038] cleanup+0x5/0xbfc [mlx5_core] [ 342.678094] __x64_sys_delete_module+0x16b/0x240 [ 342.683725] ? do_syscall_64+0x1c/0x210 [ 342.688476] do_syscall_64+0x5a/0x210 [ 342.693025] entry_SYSCALL_64_after_hwframe+0x49/0xbe Fixes: 8d5d88527587 ("xdp: rhashtable with allocator ID to pointer mapping") Signed-off-by: Tariq Toukan Suggested-by: Daniel Borkmann Cc: Jesper Dangaard Brouer Acked-by: Jesper Dangaard Brouer Signed-off-by: Daniel Borkmann

xdp: Helpers for disabling napi_direct of xdp_return_frame

2018-08-10T14:12:21Z

We need some mechanism to disable napi_direct on calling xdp_return_frame_rx_napi() from some context. When veth gets support of XDP_REDIRECT, it will redirects packets which are redirected from other devices. On redirection veth will reuse xdp_mem_info of the redirection source device to make return_frame work. But in this case .ndo_xdp_xmit() called from veth redirection uses xdp_mem_info which is not guarded by NAPI, because the .ndo_xdp_xmit() is not called directly from the rxq which owns the xdp_mem_info. This approach introduces a flag in bpf_redirect_info to indicate that napi_direct should be disabled even when _rx_napi variant is used as well as helper functions to use it. A NAPI handler who wants to use this flag needs to call xdp_set_return_frame_no_direct() before processing packets, and call xdp_clear_return_frame_no_direct() after xdp_do_flush_map() before exiting NAPI. v4: - Use bpf_redirect_info for storing the flag instead of xdp_mem_info to avoid per-frame copy cost. Signed-off-by: Toshiaki Makita Signed-off-by: Daniel Borkmann

Revert "xdp: add NULL pointer check in __xdp_return()"

2018-08-10T14:06:48Z

This reverts commit 36e0f12bbfd3016f495904b35e41c5711707509f. The reverted commit adds a WARN to check against NULL entries in the mem_id_ht rhashtable. Any kernel path implementing the XDP (generic or driver) fast path is required to make a paired xdp_rxq_info_reg/xdp_rxq_info_unreg call for proper function. In addition, a driver using a different allocation scheme than the default MEM_TYPE_PAGE_SHARED is required to additionally call xdp_rxq_info_reg_mem_model. For MEM_TYPE_ZERO_COPY, an xdp_rxq_info_reg_mem_model call ensures that the mem_id_ht rhashtable has a properly inserted allocator id. If not, this would be a driver bug. A NULL pointer kernel OOPS is preferred to the WARN. Suggested-by: Jesper Dangaard Brouer Signed-off-by: Björn Töpel Acked-by: Jesper Dangaard Brouer Signed-off-by: Daniel Borkmann

Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net

2018-08-02T17:55:32Z

The BTF conflicts were simple overlapping changes. The virtio_net conflict was an overlap of a fix of statistics counter, happening alongisde a move over to a bonafide statistics structure rather than counting value on the stack. Signed-off-by: David S. Miller

xdp: add NULL pointer check in __xdp_return()

2018-07-27T01:43:16Z

rhashtable_lookup() can return NULL. so that NULL pointer check routine should be added. Fixes: 02b55e5657c3 ("xdp: add MEM_TYPE_ZERO_COPY") Signed-off-by: Taehee Yoo Acked-by: Martin KaFai Lau Acked-by: Björn Töpel Signed-off-by: Daniel Borkmann

xdp: factor out common program/flags handling from drivers

2018-07-13T18:26:35Z

Basic operations drivers perform during xdp setup and query can be moved to helpers in the core. Encapsulate program and flags into a structure and add helpers. Note that the structure is intended as the "main" program information source in the driver. Most drivers will additionally place the program pointer in their fast path or ring structures. The helpers don't have a huge impact now, but they will decrease the code duplication when programs can be installed in HW and driver at the same time. Encapsulating the basic operations in helpers will hopefully also reduce the number of changes to drivers which adopt them. Helpers could really be static inline, but they depend on definition of struct netdev_bpf which means they'd have to be placed in netdevice.h, an already 4500 line header. Signed-off-by: Jakub Kicinski Reviewed-by: Quentin Monnet Signed-off-by: Daniel Borkmann

rhashtable: remove nulls_base and related code.

2018-06-22T04:43:27Z

This "feature" is unused, undocumented, and untested and so doesn't really belong. A patch is under development to properly implement support for detecting when a search gets diverted down a different chain, which the common purpose of nulls markers. This patch actually fixes a bug too. The table resizing allows a table to grow to 2^31 buckets, but the hash is truncated to 27 bits - any growth beyond 2^27 is wasteful an ineffective. This patch results in NULLS_MARKER(0) being used for all chains, and leaves the use of rht_is_a_null() to test for it. Acked-by: Herbert Xu Signed-off-by: NeilBrown Signed-off-by: David S. Miller