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2023-12-13xsk: Skip polling event check for unbound socketYewon Choi
[ Upstream commit e4d008d49a7135214e0ee70537405b6a069e3a3f ] In xsk_poll(), checking available events and setting mask bits should be executed only when a socket has been bound. Setting mask bits for unbound socket is meaningless. Currently, it checks events even when xsk_check_common() failed. To prevent this, we move goto location (skip_tx) after that checking. Fixes: 1596dae2f17e ("xsk: check IFF_UP earlier in Tx path") Signed-off-by: Yewon Choi <woni9911@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Magnus Karlsson <magnus.karlsson@intel.com> Link: https://lore.kernel.org/bpf/20231201061048.GA1510@libra05 Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-08-16xsk: fix refcount underflow in error pathMagnus Karlsson
commit 85c2c79a07302fe68a1ad5cc449458cc559e314d upstream. Fix a refcount underflow problem reported by syzbot that can happen when a system is running out of memory. If xp_alloc_tx_descs() fails, and it can only fail due to not having enough memory, then the error path is triggered. In this error path, the refcount of the pool is decremented as it has incremented before. However, the reference to the pool in the socket was not nulled. This means that when the socket is closed later, the socket teardown logic will think that there is a pool attached to the socket and try to decrease the refcount again, leading to a refcount underflow. I chose this fix as it involved adding just a single line. Another option would have been to move xp_get_pool() and the assignment of xs->pool to after the if-statement and using xs_umem->pool instead of xs->pool in the whole if-statement resulting in somewhat simpler code, but this would have led to much more churn in the code base perhaps making it harder to backport. Fixes: ba3beec2ec1d ("xsk: Fix possible crash when multiple sockets are created") Reported-by: syzbot+8ada0057e69293a05fd4@syzkaller.appspotmail.com Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Link: https://lore.kernel.org/r/20230809142843.13944-1-magnus.karlsson@gmail.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-08-11net: annotate data-races around sk->sk_markEric Dumazet
[ Upstream commit 3c5b4d69c358a9275a8de98f87caf6eda644b086 ] sk->sk_mark is often read while another thread could change the value. Fixes: 4a19ec5800fc ("[NET]: Introducing socket mark socket option.") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-19xsk: Honor SO_BINDTODEVICE on bindIlya Maximets
[ Upstream commit f7306acec9aae9893d15e745c8791124d42ab10a ] Initial creation of an AF_XDP socket requires CAP_NET_RAW capability. A privileged process might create the socket and pass it to a non-privileged process for later use. However, that process will be able to bind the socket to any network interface. Even though it will not be able to receive any traffic without modification of the BPF map, the situation is not ideal. Sockets already have a mechanism that can be used to restrict what interface they can be attached to. That is SO_BINDTODEVICE. To change the SO_BINDTODEVICE binding the process will need CAP_NET_RAW. Make xsk_bind() honor the SO_BINDTODEVICE in order to allow safer workflow when non-privileged process is using AF_XDP. The intended workflow is following: 1. First process creates a bare socket with socket(AF_XDP, ...). 2. First process loads the XSK program to the interface. 3. First process adds the socket fd to a BPF map. 4. First process ties socket fd to a particular interface using SO_BINDTODEVICE. 5. First process sends socket fd to a second process. 6. Second process allocates UMEM. 7. Second process binds socket to the interface with bind(...). 8. Second process sends/receives the traffic. All the steps above are possible today if the first process is privileged and the second one has sufficient RLIMIT_MEMLOCK and no capabilities. However, the second process will be able to bind the socket to any interface it wants on step 7 and send traffic from it. With the proposed change, the second process will be able to bind the socket only to a specific interface chosen by the first process at step 4. Fixes: 965a99098443 ("xsk: add support for bind for Rx") Signed-off-by: Ilya Maximets <i.maximets@ovn.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Magnus Karlsson <magnus.karlsson@intel.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/bpf/20230703175329.3259672-1-i.maximets@ovn.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-10xsk: check IFF_UP earlier in Tx pathMaciej Fijalkowski
[ Upstream commit 1596dae2f17ec5c6e8c8f0e3fec78c5ae55c1e0b ] Xsk Tx can be triggered via either sendmsg() or poll() syscalls. These two paths share a call to common function xsk_xmit() which has two sanity checks within. A pseudo code example to show the two paths: __xsk_sendmsg() : xsk_poll(): if (unlikely(!xsk_is_bound(xs))) if (unlikely(!xsk_is_bound(xs))) return -ENXIO; return mask; if (unlikely(need_wait)) (...) return -EOPNOTSUPP; xsk_xmit() mark napi id (...) xsk_xmit() xsk_xmit(): if (unlikely(!(xs->dev->flags & IFF_UP))) return -ENETDOWN; if (unlikely(!xs->tx)) return -ENOBUFS; As it can be observed above, in sendmsg() napi id can be marked on interface that was not brought up and this causes a NULL ptr dereference: [31757.505631] BUG: kernel NULL pointer dereference, address: 0000000000000018 [31757.512710] #PF: supervisor read access in kernel mode [31757.517936] #PF: error_code(0x0000) - not-present page [31757.523149] PGD 0 P4D 0 [31757.525726] Oops: 0000 [#1] PREEMPT SMP NOPTI [31757.530154] CPU: 26 PID: 95641 Comm: xdpsock Not tainted 6.2.0-rc5+ #40 [31757.536871] Hardware name: Intel Corporation S2600WFT/S2600WFT, BIOS SE5C620.86B.02.01.0008.031920191559 03/19/2019 [31757.547457] RIP: 0010:xsk_sendmsg+0xde/0x180 [31757.551799] Code: 00 75 a2 48 8b 00 a8 04 75 9b 84 d2 74 69 8b 85 14 01 00 00 85 c0 75 1b 48 8b 85 28 03 00 00 48 8b 80 98 00 00 00 48 8b 40 20 <8b> 40 18 89 85 14 01 00 00 8b bd 14 01 00 00 81 ff 00 01 00 00 0f [31757.570840] RSP: 0018:ffffc90034f27dc0 EFLAGS: 00010246 [31757.576143] RAX: 0000000000000000 RBX: ffffc90034f27e18 RCX: 0000000000000000 [31757.583389] RDX: 0000000000000001 RSI: ffffc90034f27e18 RDI: ffff88984cf3c100 [31757.590631] RBP: ffff88984714a800 R08: ffff88984714a800 R09: 0000000000000000 [31757.597877] R10: 0000000000000001 R11: 0000000000000000 R12: 00000000fffffffa [31757.605123] R13: 0000000000000000 R14: 0000000000000003 R15: 0000000000000000 [31757.612364] FS: 00007fb4c5931180(0000) GS:ffff88afdfa00000(0000) knlGS:0000000000000000 [31757.620571] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [31757.626406] CR2: 0000000000000018 CR3: 000000184b41c003 CR4: 00000000007706e0 [31757.633648] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [31757.640894] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [31757.648139] PKRU: 55555554 [31757.650894] Call Trace: [31757.653385] <TASK> [31757.655524] sock_sendmsg+0x8f/0xa0 [31757.659077] ? sockfd_lookup_light+0x12/0x70 [31757.663416] __sys_sendto+0xfc/0x170 [31757.667051] ? do_sched_setscheduler+0xdb/0x1b0 [31757.671658] __x64_sys_sendto+0x20/0x30 [31757.675557] do_syscall_64+0x38/0x90 [31757.679197] entry_SYSCALL_64_after_hwframe+0x72/0xdc [31757.687969] Code: 8e f6 ff 44 8b 4c 24 2c 4c 8b 44 24 20 41 89 c4 44 8b 54 24 28 48 8b 54 24 18 b8 2c 00 00 00 48 8b 74 24 10 8b 7c 24 08 0f 05 <48> 3d 00 f0 ff ff 77 3a 44 89 e7 48 89 44 24 08 e8 b5 8e f6 ff 48 [31757.707007] RSP: 002b:00007ffd49c73c70 EFLAGS: 00000293 ORIG_RAX: 000000000000002c [31757.714694] RAX: ffffffffffffffda RBX: 000055a996565380 RCX: 00007fb4c5727c16 [31757.721939] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 [31757.729184] RBP: 0000000000000040 R08: 0000000000000000 R09: 0000000000000000 [31757.736429] R10: 0000000000000040 R11: 0000000000000293 R12: 0000000000000000 [31757.743673] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [31757.754940] </TASK> To fix this, let's make xsk_xmit a function that will be responsible for generic Tx, where RCU is handled accordingly and pull out sanity checks and xs->zc handling. Populate sanity checks to __xsk_sendmsg() and xsk_poll(). Fixes: ca2e1a627035 ("xsk: Mark napi_id on sendmsg()") Fixes: 18b1ab7aa76b ("xsk: Fix race at socket teardown") Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com> Link: https://lore.kernel.org/r/20230215143309.13145-1-maciej.fijalkowski@intel.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-09-22xsk: Inherit need_wakeup flag for shared socketsJalal Mostafa
The flag for need_wakeup is not set for xsks with `XDP_SHARED_UMEM` flag and of different queue ids and/or devices. They should inherit the flag from the first socket buffer pool since no flags can be specified once `XDP_SHARED_UMEM` is specified. Fixes: b5aea28dca134 ("xsk: Add shared umem support between queue ids") Signed-off-by: Jalal Mostafa <jalal.a.mostapha@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Magnus Karlsson <magnus.karlsson@intel.com> Link: https://lore.kernel.org/bpf/20220921135701.10199-1-jalal.a.mostapha@gmail.com
2022-08-31xsk: Fix backpressure mechanism on TxMaciej Fijalkowski
Commit d678cbd2f867 ("xsk: Fix handling of invalid descriptors in XSK TX batching API") fixed batch API usage against set of descriptors with invalid ones but introduced a problem when AF_XDP SW rings are smaller than HW ones. Mismatch of reported Tx'ed frames between HW generator and user space app was observed. It turned out that backpressure mechanism became a bottleneck when the amount of produced descriptors to CQ is lower than what we grabbed from XSK Tx ring. Say that 512 entries had been taken from XSK Tx ring but we had only 490 free entries in CQ. Then callsite (ZC driver) will produce only 490 entries onto HW Tx ring but 512 entries will be released from Tx ring and this is what will be seen by the user space. In order to fix this case, mix XSK Tx/CQ ring interractions by moving around internal functions and changing call order: * pull out xskq_prod_nb_free() from xskq_prod_reserve_addr_batch() up to xsk_tx_peek_release_desc_batch(); ** move xskq_cons_release_n() into xskq_cons_read_desc_batch() After doing so, algorithm can be described as follows: 1. lookup Tx entries 2. use value from 1. to reserve space in CQ (*) 3. Read from Tx ring as much descriptors as value from 2 3a. release descriptors from XSK Tx ring (**) 4. Finally produce addresses to CQ Fixes: d678cbd2f867 ("xsk: Fix handling of invalid descriptors in XSK TX batching API") Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20220830121705.8618-1-maciej.fijalkowski@intel.com
2022-07-14xsk: Mark napi_id on sendmsg()Maciej Fijalkowski
When application runs in busy poll mode and does not receive a single packet but only sends them, it is currently impossible to get into napi_busy_loop() as napi_id is only marked on Rx side in xsk_rcv_check(). In there, napi_id is being taken from xdp_rxq_info carried by xdp_buff. From Tx perspective, we do not have access to it. What we have handy is the xsk pool. Xsk pool works on a pool of internal xdp_buff wrappers called xdp_buff_xsk. AF_XDP ZC enabled drivers call xp_set_rxq_info() so each of xdp_buff_xsk has a valid pointer to xdp_rxq_info of underlying queue. Therefore, on Tx side, napi_id can be pulled from xs->pool->heads[0].xdp.rxq->napi_id. Hide this pointer chase under helper function, xsk_pool_get_napi_id(). Do this only for sockets working in ZC mode as otherwise rxq pointers would not be initialized. Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Magnus Karlsson <magnus.karlsson@intel.com> Link: https://lore.kernel.org/bpf/20220707130842.49408-1-maciej.fijalkowski@intel.com
2022-06-14xsk: Fix generic transmit when completion queue reservation failsCiara Loftus
Two points of potential failure in the generic transmit function are: 1. completion queue (cq) reservation failure. 2. skb allocation failure Originally the cq reservation was performed first, followed by the skb allocation. Commit 675716400da6 ("xdp: fix possible cq entry leak") reversed the order because at the time there was no mechanism available to undo the cq reservation which could have led to possible cq entry leaks in the event of skb allocation failure. However if the skb allocation is performed first and the cq reservation then fails, the xsk skb destructor is called which blindly adds the skb address to the already full cq leading to undefined behavior. This commit restores the original order (cq reservation followed by skb allocation) and uses the xskq_prod_cancel helper to undo the cq reserve in event of skb allocation failure. Fixes: 675716400da6 ("xdp: fix possible cq entry leak") Signed-off-by: Ciara Loftus <ciara.loftus@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Magnus Karlsson <magnus.karlsson@intel.com> Link: https://lore.kernel.org/bpf/20220614070746.8871-1-ciara.loftus@intel.com
2022-06-08xsk: Fix handling of invalid descriptors in XSK TX batching APIMaciej Fijalkowski
xdpxceiver run on a AF_XDP ZC enabled driver revealed a problem with XSK Tx batching API. There is a test that checks how invalid Tx descriptors are handled by AF_XDP. Each valid descriptor is followed by invalid one on Tx side whereas the Rx side expects only to receive a set of valid descriptors. In current xsk_tx_peek_release_desc_batch() function, the amount of available descriptors is hidden inside xskq_cons_peek_desc_batch(). This can be problematic in cases where invalid descriptors are present due to the fact that xskq_cons_peek_desc_batch() returns only a count of valid descriptors. This means that it is impossible to properly update XSK ring state when calling xskq_cons_release_n(). To address this issue, pull out the contents of xskq_cons_peek_desc_batch() so that callers (currently only xsk_tx_peek_release_desc_batch()) will always be able to update the state of ring properly, as total count of entries is now available and use this value as an argument in xskq_cons_release_n(). By doing so, xskq_cons_peek_desc_batch() can be dropped altogether. Fixes: 9349eb3a9d2a ("xsk: Introduce batched Tx descriptor interfaces") Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Magnus Karlsson <magnus.karlsson@intel.com> Link: https://lore.kernel.org/bpf/20220607142200.576735-1-maciej.fijalkowski@intel.com
2022-04-28Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
include/linux/netdevice.h net/core/dev.c 6510ea973d8d ("net: Use this_cpu_inc() to increment net->core_stats") 794c24e9921f ("net-core: rx_otherhost_dropped to core_stats") https://lore.kernel.org/all/20220428111903.5f4304e0@canb.auug.org.au/ drivers/net/wan/cosa.c d48fea8401cf ("net: cosa: fix error check return value of register_chrdev()") 89fbca3307d4 ("net: wan: remove support for COSA and SRP synchronous serial boards") https://lore.kernel.org/all/20220428112130.1f689e5e@canb.auug.org.au/ Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-04-26xsk: Fix possible crash when multiple sockets are createdMaciej Fijalkowski
Fix a crash that happens if an Rx only socket is created first, then a second socket is created that is Tx only and bound to the same umem as the first socket and also the same netdev and queue_id together with the XDP_SHARED_UMEM flag. In this specific case, the tx_descs array page pool was not created by the first socket as it was an Rx only socket. When the second socket is bound it needs this tx_descs array of this shared page pool as it has a Tx component, but unfortunately it was never allocated, leading to a crash. Note that this array is only used for zero-copy drivers using the batched Tx APIs, currently only ice and i40e. [ 5511.150360] BUG: kernel NULL pointer dereference, address: 0000000000000008 [ 5511.158419] #PF: supervisor write access in kernel mode [ 5511.164472] #PF: error_code(0x0002) - not-present page [ 5511.170416] PGD 0 P4D 0 [ 5511.173347] Oops: 0002 [#1] PREEMPT SMP PTI [ 5511.178186] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G E 5.18.0-rc1+ #97 [ 5511.187245] Hardware name: Intel Corp. GRANTLEY/GRANTLEY, BIOS GRRFCRB1.86B.0276.D07.1605190235 05/19/2016 [ 5511.198418] RIP: 0010:xsk_tx_peek_release_desc_batch+0x198/0x310 [ 5511.205375] Code: c0 83 c6 01 84 c2 74 6d 8d 46 ff 23 07 44 89 e1 48 83 c0 14 48 c1 e1 04 48 c1 e0 04 48 03 47 10 4c 01 c1 48 8b 50 08 48 8b 00 <48> 89 51 08 48 89 01 41 80 bd d7 00 00 00 00 75 82 48 8b 19 49 8b [ 5511.227091] RSP: 0018:ffffc90000003dd0 EFLAGS: 00010246 [ 5511.233135] RAX: 0000000000000000 RBX: ffff88810c8da600 RCX: 0000000000000000 [ 5511.241384] RDX: 000000000000003c RSI: 0000000000000001 RDI: ffff888115f555c0 [ 5511.249634] RBP: ffffc90000003e08 R08: 0000000000000000 R09: ffff889092296b48 [ 5511.257886] R10: 0000ffffffffffff R11: ffff889092296800 R12: 0000000000000000 [ 5511.266138] R13: ffff88810c8db500 R14: 0000000000000040 R15: 0000000000000100 [ 5511.274387] FS: 0000000000000000(0000) GS:ffff88903f800000(0000) knlGS:0000000000000000 [ 5511.283746] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 5511.290389] CR2: 0000000000000008 CR3: 00000001046e2001 CR4: 00000000003706f0 [ 5511.298640] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 5511.306892] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 5511.315142] Call Trace: [ 5511.317972] <IRQ> [ 5511.320301] ice_xmit_zc+0x68/0x2f0 [ice] [ 5511.324977] ? ktime_get+0x38/0xa0 [ 5511.328913] ice_napi_poll+0x7a/0x6a0 [ice] [ 5511.333784] __napi_poll+0x2c/0x160 [ 5511.337821] net_rx_action+0xdd/0x200 [ 5511.342058] __do_softirq+0xe6/0x2dd [ 5511.346198] irq_exit_rcu+0xb5/0x100 [ 5511.350339] common_interrupt+0xa4/0xc0 [ 5511.354777] </IRQ> [ 5511.357201] <TASK> [ 5511.359625] asm_common_interrupt+0x1e/0x40 [ 5511.364466] RIP: 0010:cpuidle_enter_state+0xd2/0x360 [ 5511.370211] Code: 49 89 c5 0f 1f 44 00 00 31 ff e8 e9 00 7b ff 45 84 ff 74 12 9c 58 f6 c4 02 0f 85 72 02 00 00 31 ff e8 02 0c 80 ff fb 45 85 f6 <0f> 88 11 01 00 00 49 63 c6 4c 2b 2c 24 48 8d 14 40 48 8d 14 90 49 [ 5511.391921] RSP: 0018:ffffffff82a03e60 EFLAGS: 00000202 [ 5511.397962] RAX: ffff88903f800000 RBX: 0000000000000001 RCX: 000000000000001f [ 5511.406214] RDX: 0000000000000000 RSI: ffffffff823400b9 RDI: ffffffff8234c046 [ 5511.424646] RBP: ffff88810a384800 R08: 000005032a28c046 R09: 0000000000000008 [ 5511.443233] R10: 000000000000000b R11: 0000000000000006 R12: ffffffff82bcf700 [ 5511.461922] R13: 000005032a28c046 R14: 0000000000000001 R15: 0000000000000000 [ 5511.480300] cpuidle_enter+0x29/0x40 [ 5511.494329] do_idle+0x1c7/0x250 [ 5511.507610] cpu_startup_entry+0x19/0x20 [ 5511.521394] start_kernel+0x649/0x66e [ 5511.534626] secondary_startup_64_no_verify+0xc3/0xcb [ 5511.549230] </TASK> Detect such case during bind() and allocate this memory region via newly introduced xp_alloc_tx_descs(). Also, use kvcalloc instead of kcalloc as for other buffer pool allocations, so that it matches the kvfree() from xp_destroy(). Fixes: d1bc532e99be ("i40e: xsk: Move tmp desc array from driver to pool") Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Magnus Karlsson <magnus.karlsson@intel.com> Link: https://lore.kernel.org/bpf/20220425153745.481322-1-maciej.fijalkowski@intel.com
2022-04-15xsk: Diversify return codes in xsk_rcv_check()Maciej Fijalkowski
Inspired by patch that made xdp_do_redirect() return values for XSKMAP more meaningful, return -ENXIO instead of -EINVAL for socket being unbound in xsk_rcv_check() as this is the usual value that is returned for such event. In turn, it is now possible to easily distinguish what went wrong, which is a bit harder when for both cases checked, -EINVAL was returned. Return codes can be counted in a nice way via bpftrace oneliner that Jesper has shown: bpftrace -e 'tracepoint:xdp:xdp_redirect* {@err[-args->err] = count();}' Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Link: https://lore.kernel.org/bpf/20220413153015.453864-3-maciej.fijalkowski@intel.com
2022-04-15xsk: Improve xdp_do_redirect() error codesBjörn Töpel
The error codes returned by xdp_do_redirect() when redirecting a frame to an AF_XDP socket has not been very useful. A driver could not distinguish between different errors. Prior this change the following codes where used: Socket not bound or incorrect queue/netdev: EINVAL XDP frame/AF_XDP buffer size mismatch: ENOSPC Could not allocate buffer (copy mode): ENOSPC AF_XDP Rx buffer full: ENOSPC After this change: Socket not bound or incorrect queue/netdev: EINVAL XDP frame/AF_XDP buffer size mismatch: ENOSPC Could not allocate buffer (copy mode): ENOMEM AF_XDP Rx buffer full: ENOBUFS An AF_XDP zero-copy driver can now potentially determine if the failure was due to a full Rx buffer, and if so stop processing more frames, yielding to the userland AF_XDP application. Signed-off-by: Björn Töpel <bjorn@kernel.org> Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Link: https://lore.kernel.org/bpf/20220413153015.453864-2-maciej.fijalkowski@intel.com
2022-04-07xsk: Fix l2fwd for copy mode + busy poll comboMaciej Fijalkowski
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: a0731952d9cd ("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
2022-03-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Merge in overtime fixes, no conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-02-28xsk: Fix race at socket teardownMagnus Karlsson
Fix a race in the xsk socket teardown code that can lead to a NULL pointer dereference splat. The current xsk unbind code in xsk_unbind_dev() starts by setting xs->state to XSK_UNBOUND, sets xs->dev to NULL and then waits for any NAPI processing to terminate using synchronize_net(). After that, the release code starts to tear down the socket state and free allocated memory. BUG: kernel NULL pointer dereference, address: 00000000000000c0 PGD 8000000932469067 P4D 8000000932469067 PUD 0 Oops: 0000 [#1] PREEMPT SMP PTI CPU: 25 PID: 69132 Comm: grpcpp_sync_ser Tainted: G I 5.16.0+ #2 Hardware name: Dell Inc. PowerEdge R730/0599V5, BIOS 1.2.10 03/09/2015 RIP: 0010:__xsk_sendmsg+0x2c/0x690 [...] RSP: 0018:ffffa2348bd13d50 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000040 RCX: ffff8d5fc632d258 RDX: 0000000000400000 RSI: ffffa2348bd13e10 RDI: ffff8d5fc5489800 RBP: ffffa2348bd13db0 R08: 0000000000000000 R09: 00007ffffffff000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8d5fc5489800 R13: ffff8d5fcb0f5140 R14: ffff8d5fcb0f5140 R15: 0000000000000000 FS: 00007f991cff9400(0000) GS:ffff8d6f1f700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000000000c0 CR3: 0000000114888005 CR4: 00000000001706e0 Call Trace: <TASK> ? aa_sk_perm+0x43/0x1b0 xsk_sendmsg+0xf0/0x110 sock_sendmsg+0x65/0x70 __sys_sendto+0x113/0x190 ? debug_smp_processor_id+0x17/0x20 ? fpregs_assert_state_consistent+0x23/0x50 ? exit_to_user_mode_prepare+0xa5/0x1d0 __x64_sys_sendto+0x29/0x30 do_syscall_64+0x3b/0xc0 entry_SYSCALL_64_after_hwframe+0x44/0xae There are two problems with the current code. First, setting xs->dev to NULL before waiting for all users to stop using the socket is not correct. The entry to the data plane functions xsk_poll(), xsk_sendmsg(), and xsk_recvmsg() are all guarded by a test that xs->state is in the state XSK_BOUND and if not, it returns right away. But one process might have passed this test but still have not gotten to the point in which it uses xs->dev in the code. In this interim, a second process executing xsk_unbind_dev() might have set xs->dev to NULL which will lead to a crash for the first process. The solution here is just to get rid of this NULL assignment since it is not used anymore. Before commit 42fddcc7c64b ("xsk: use state member for socket synchronization"), xs->dev was the gatekeeper to admit processes into the data plane functions, but it was replaced with the state variable xs->state in the aforementioned commit. The second problem is that synchronize_net() does not wait for any process in xsk_poll(), xsk_sendmsg(), or xsk_recvmsg() to complete, which means that the state they rely on might be cleaned up prematurely. This can happen when the notifier gets called (at driver unload for example) as it uses xsk_unbind_dev(). Solve this by extending the RCU critical region from just the ndo_xsk_wakeup to the whole functions mentioned above, so that both the test of xs->state == XSK_BOUND and the last use of any member of xs is covered by the RCU critical section. This will guarantee that when synchronize_net() completes, there will be no processes left executing xsk_poll(), xsk_sendmsg(), or xsk_recvmsg() and state can be cleaned up safely. Note that we need to drop the RCU lock for the skb xmit path as it uses functions that might sleep. Due to this, we have to retest the xs->state after we grab the mutex that protects the skb xmit code from, among a number of things, an xsk_unbind_dev() being executed from the notifier at the same time. Fixes: 42fddcc7c64b ("xsk: use state member for socket synchronization") Reported-by: Elza Mathew <elza.mathew@intel.com> Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Björn Töpel <bjorn@kernel.org> Link: https://lore.kernel.org/bpf/20220228094552.10134-1-magnus.karlsson@gmail.com
2022-01-27i40e: xsk: Move tmp desc array from driver to poolMagnus Karlsson
Move desc_array from the driver to the pool. The reason behind this is that we can then reuse this array as a temporary storage for descriptors in all zero-copy drivers that use the batched interface. This will make it easier to add batching to more drivers. i40e is the only driver that has a batched Tx zero-copy implementation, so no need to touch any other driver. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Alexander Lobakin <alexandr.lobakin@intel.com> Link: https://lore.kernel.org/bpf/20220125160446.78976-6-maciej.fijalkowski@intel.com
2022-01-05Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-17Revert "xsk: Do not sleep in poll() when need_wakeup set"Magnus Karlsson
This reverts commit bd0687c18e635b63233dc87f38058cd728802ab4. This patch causes a Tx only workload to go to sleep even when it does not have to, leading to misserable performance in skb mode. It fixed one rare problem but created a much worse one, so this need to be reverted while I try to craft a proper solution to the original problem. Fixes: bd0687c18e63 ("xsk: Do not sleep in poll() when need_wakeup set") Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20211217145646.26449-1-magnus.karlsson@gmail.com
2021-12-16Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-14xsk: Do not sleep in poll() when need_wakeup setMagnus Karlsson
Do not sleep in poll() when the need_wakeup flag is set. When this flag is set, the application needs to explicitly wake up the driver with a syscall (poll, recvmsg, sendmsg, etc.) to guarantee that Rx and/or Tx processing will be processed promptly. But the current code in poll(), sleeps first then wakes up the driver. This means that no driver processing will occur (baring any interrupts) until the timeout has expired. Fix this by checking the need_wakeup flag first and if set, wake the driver and return to the application. Only if need_wakeup is not set should the process sleep if there is a timeout set in the poll() call. Fixes: 77cd0d7b3f25 ("xsk: add support for need_wakeup flag in AF_XDP rings") Reported-by: Keith Wiles <keith.wiles@intel.com> Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Link: https://lore.kernel.org/bpf/20211214102607.7677-1-magnus.karlsson@gmail.com
2021-11-16net: drop nopreempt requirement on sock_prot_inuse_add()Eric Dumazet
This is distracting really, let's make this simpler, because many callers had to take care of this by themselves, even if on x86 this adds more code than really needed. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-28xsk: Optimize for aligned caseMagnus Karlsson
Optimize for the aligned case by precomputing the parameter values of the xdp_buff_xsk and xdp_buff structures in the heads array. We can do this as the heads array size is equal to the number of chunks in the umem for the aligned case. Then every entry in this array will reflect a certain chunk/frame and can therefore be prepopulated with the correct values and we can drop the use of the free_heads stack. Note that it is not possible to allocate more buffers than what has been allocated in the aligned case since each chunk can only contain a single buffer. We can unfortunately not do this in the unaligned case as one chunk might contain multiple buffers. In this case, we keep the old scheme of populating a heads entry every time it is used and using the free_heads stack. Also move xp_release() and xp_get_handle() to xsk_buff_pool.h. They were for some reason in xsk.c even though they are buffer pool operations. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20210922075613.12186-7-magnus.karlsson@gmail.com
2021-06-29net: sock: introduce sk_error_reportAlexander Aring
This patch introduces a function wrapper to call the sk_error_report callback. That will prepare to add additional handling whenever sk_error_report is called, for example to trace socket errors. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-24xdp: Add proper __rcu annotations to redirect map entriesToke Høiland-Jørgensen
XDP_REDIRECT works by a three-step process: the bpf_redirect() and bpf_redirect_map() helpers will lookup the target of the redirect and store it (along with some other metadata) in a per-CPU struct bpf_redirect_info. Next, when the program returns the XDP_REDIRECT return code, the driver will call xdp_do_redirect() which will use the information thus stored to actually enqueue the frame into a bulk queue structure (that differs slightly by map type, but shares the same principle). Finally, before exiting its NAPI poll loop, the driver will call xdp_do_flush(), which will flush all the different bulk queues, thus completing the redirect. Pointers to the map entries will be kept around for this whole sequence of steps, protected by RCU. However, there is no top-level rcu_read_lock() in the core code; instead drivers add their own rcu_read_lock() around the XDP portions of the code, but somewhat inconsistently as Martin discovered[0]. However, things still work because everything happens inside a single NAPI poll sequence, which means it's between a pair of calls to local_bh_disable()/local_bh_enable(). So Paul suggested[1] that we could document this intention by using rcu_dereference_check() with rcu_read_lock_bh_held() as a second parameter, thus allowing sparse and lockdep to verify that everything is done correctly. This patch does just that: we add an __rcu annotation to the map entry pointers and remove the various comments explaining the NAPI poll assurance strewn through devmap.c in favour of a longer explanation in filter.c. The goal is to have one coherent documentation of the entire flow, and rely on the RCU annotations as a "standard" way of communicating the flow in the map code (which can additionally be understood by sparse and lockdep). The RCU annotation replacements result in a fairly straight-forward replacement where READ_ONCE() becomes rcu_dereference_check(), WRITE_ONCE() becomes rcu_assign_pointer() and xchg() and cmpxchg() gets wrapped in the proper constructs to cast the pointer back and forth between __rcu and __kernel address space (for the benefit of sparse). The one complication is that xskmap has a few constructions where double-pointers are passed back and forth; these simply all gain __rcu annotations, and only the final reference/dereference to the inner-most pointer gets changed. With this, everything can be run through sparse without eliciting complaints, and lockdep can verify correctness even without the use of rcu_read_lock() in the drivers. Subsequent patches will clean these up from the drivers. [0] https://lore.kernel.org/bpf/20210415173551.7ma4slcbqeyiba2r@kafai-mbp.dhcp.thefacebook.com/ [1] https://lore.kernel.org/bpf/20210419165837.GA975577@paulmck-ThinkPad-P17-Gen-1/ Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20210624160609.292325-6-toke@redhat.com
2021-04-23xsk: Align XDP socket batch size with DPDKLi RongQing
DPDK default burst size is 32, however, kernel xsk sendto syscall can not handle all 32 at one time, and return with error. So make kernel XDP socket batch size larger to avoid unnecessary syscall fail and context switch which will help to increase performance. Signed-off-by: Li RongQing <lirongqing@baidu.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Magnus Karlsson <magnus.karlsson@intel.com> Link: https://lore.kernel.org/bpf/1618378752-4191-1-git-send-email-lirongqing@baidu.com
2021-02-25xsk: Build skb by page (aka generic zerocopy xmit)Xuan Zhuo
This patch is used to construct skb based on page to save memory copy overhead. This function is implemented based on IFF_TX_SKB_NO_LINEAR. Only the network card priv_flags supports IFF_TX_SKB_NO_LINEAR will use page to directly construct skb. If this feature is not supported, it is still necessary to copy data to construct skb. ---------------- Performance Testing ------------ The test environment is Aliyun ECS server. Test cmd: ``` xdpsock -i eth0 -t -S -s <msg size> ``` Test result data: size 64 512 1024 1500 copy 1916747 1775988 1600203 1440054 page 1974058 1953655 1945463 1904478 percent 3.0% 10.0% 21.58% 32.3% Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Signed-off-by: Alexander Lobakin <alobakin@pm.me> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Dust Li <dust.li@linux.alibaba.com> Acked-by: Magnus Karlsson <magnus.karlsson@intel.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20210218204908.5455-6-alobakin@pm.me
2021-02-25xsk: Respect device's headroom and tailroom on generic xmit pathAlexander Lobakin
xsk_generic_xmit() allocates a new skb and then queues it for xmitting. The size of new skb's headroom is desc->len, so it comes to the driver/device with no reserved headroom and/or tailroom. Lots of drivers need some headroom (and sometimes tailroom) to prepend (and/or append) some headers or data, e.g. CPU tags, device-specific headers/descriptors (LSO, TLS etc.), and if case of no available space skb_cow_head() will reallocate the skb. Reallocations are unwanted on fast-path, especially when it comes to XDP, so generic XSK xmit should reserve the spaces declared in dev->needed_headroom and dev->needed tailroom to avoid them. Note on max(NET_SKB_PAD, L1_CACHE_ALIGN(dev->needed_headroom)): Usually, output functions reserve LL_RESERVED_SPACE(dev), which consists of dev->hard_header_len + dev->needed_headroom, aligned by 16. However, on XSK xmit hard header is already here in the chunk, so hard_header_len is not needed. But it'd still be better to align data up to cacheline, while reserving no less than driver requests for headroom. NET_SKB_PAD here is to double-insure there will be no reallocations even when the driver advertises no needed_headroom, but in fact need it (not so rare case). Fixes: 35fcde7f8deb ("xsk: support for Tx") Signed-off-by: Alexander Lobakin <alobakin@pm.me> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Magnus Karlsson <magnus.karlsson@intel.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20210218204908.5455-5-alobakin@pm.me
2021-01-25xsk: Remove explicit_free parameter from __xsk_rcv()Björn Töpel
The explicit_free parameter of the __xsk_rcv() function was used to mark whether the call was via the generic XDP or the native XDP path. Instead of clutter the code with if-statements and "true/false" parameters which are hard to understand, simply move the explicit free to the __xsk_map_redirect() which is always called from the native XDP path. Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Link: https://lore.kernel.org/bpf/20210122105351.11751-2-bjorn.topel@gmail.com
2021-01-19xsk: Clear pool even for inactive queuesMaxim Mikityanskiy
The number of queues can change by other means, rather than ethtool. For example, attaching an mqprio qdisc with num_tc > 1 leads to creating multiple sets of TX queues, which may be then destroyed when mqprio is deleted. If an AF_XDP socket is created while mqprio is active, dev->_tx[queue_id].pool will be filled, but then real_num_tx_queues may decrease with deletion of mqprio, which will mean that the pool won't be NULLed, and a further increase of the number of TX queues may expose a dangling pointer. To avoid any potential misbehavior, this commit clears pool for RX and TX queues, regardless of real_num_*_queues, still taking into consideration num_*_queues to avoid overflows. Fixes: 1c1efc2af158 ("xsk: Create and free buffer pool independently from umem") Fixes: a41b4f3c58dd ("xsk: simplify xdp_clear_umem_at_qid implementation") Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Björn Töpel <bjorn.topel@intel.com> Link: https://lore.kernel.org/bpf/20210118160333.333439-1-maximmi@mellanox.com
2020-12-18xsk: Rollback reservation at NETDEV_TX_BUSYMagnus Karlsson
Rollback the reservation in the completion ring when we get a NETDEV_TX_BUSY. When this error is received from the driver, we are supposed to let the user application retry the transmit again. And in order to do this, we need to roll back the failed send so it can be retried. Unfortunately, we did not cancel the reservation we had made in the completion ring. By not doing this, we actually make the completion ring one entry smaller per NETDEV_TX_BUSY error we get, and after enough of these errors the completion ring will be of size zero and transmit will stop working. Fix this by cancelling the reservation when we get a NETDEV_TX_BUSY error. Fixes: 642e450b6b59 ("xsk: Do not discard packet when NETDEV_TX_BUSY") Reported-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Björn Töpel <bjorn.topel@intel.com> Link: https://lore.kernel.org/bpf/20201218134525.13119-3-magnus.karlsson@gmail.com
2020-12-18xsk: Fix race in SKB mode transmit with shared cqMagnus Karlsson
Fix a race when multiple sockets are simultaneously calling sendto() when the completion ring is shared in the SKB case. This is the case when you share the same netdev and queue id through the XDP_SHARED_UMEM bind flag. The problem is that multiple processes can be in xsk_generic_xmit() and call the backpressure mechanism in xskq_prod_reserve(xs->pool->cq). As this is a shared resource in this specific scenario, a race might occur since the rings are single-producer single-consumer. Fix this by moving the tx_completion_lock from the socket to the pool as the pool is shared between the sockets that share the completion ring. (The pool is not shared when this is not the case.) And then protect the accesses to xskq_prod_reserve() with this lock. The tx_completion_lock is renamed cq_lock to better reflect that it protects accesses to the potentially shared completion ring. Fixes: 35fcde7f8deb ("xsk: support for Tx") Reported-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Björn Töpel <bjorn.topel@intel.com> Link: https://lore.kernel.org/bpf/20201218134525.13119-2-magnus.karlsson@gmail.com
2020-12-17xsk: Fix memory leak for failed bindMagnus Karlsson
Fix a possible memory leak when a bind of an AF_XDP socket fails. When the fill and completion rings are created, they are tied to the socket. But when the buffer pool is later created at bind time, the ownership of these two rings are transferred to the buffer pool as they might be shared between sockets (and the buffer pool cannot be created until we know what we are binding to). So, before the buffer pool is created, these two rings are cleaned up with the socket, and after they have been transferred they are cleaned up together with the buffer pool. The problem is that ownership was transferred before it was absolutely certain that the buffer pool could be created and initialized correctly and when one of these errors occurred, the fill and completion rings did neither belong to the socket nor the pool and where therefore leaked. Solve this by moving the ownership transfer to the point where the buffer pool has been completely set up and there is no way it can fail. Fixes: 7361f9c3d719 ("xsk: Move fill and completion rings to buffer pool") Reported-by: syzbot+cfa88ddd0655afa88763@syzkaller.appspotmail.com Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Björn Töpel <bjorn.topel@intel.com> Link: https://lore.kernel.org/bpf/20201214085127.3960-1-magnus.karlsson@gmail.com
2020-12-14Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextJakub Kicinski
Daniel Borkmann says: ==================== pull-request: bpf-next 2020-12-14 1) Expose bpf_sk_storage_*() helpers to iterator programs, from Florent Revest. 2) Add AF_XDP selftests based on veth devs to BPF selftests, from Weqaar Janjua. 3) Support for finding BTF based kernel attach targets through libbpf's bpf_program__set_attach_target() API, from Andrii Nakryiko. 4) Permit pointers on stack for helper calls in the verifier, from Yonghong Song. 5) Fix overflows in hash map elem size after rlimit removal, from Eric Dumazet. 6) Get rid of direct invocation of llc in BPF selftests, from Andrew Delgadillo. 7) Fix xsk_recvmsg() to reorder socket state check before access, from Björn Töpel. 8) Add new libbpf API helper to retrieve ring buffer epoll fd, from Brendan Jackman. 9) Batch of minor BPF selftest improvements all over the place, from Florian Lehner, KP Singh, Jiri Olsa and various others. * https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (31 commits) selftests/bpf: Add a test for ptr_to_map_value on stack for helper access bpf: Permits pointers on stack for helper calls libbpf: Expose libbpf ring_buffer epoll_fd selftests/bpf: Add set_attach_target() API selftest for module target libbpf: Support modules in bpf_program__set_attach_target() API selftests/bpf: Silence ima_setup.sh when not running in verbose mode. selftests/bpf: Drop the need for LLVM's llc selftests/bpf: fix bpf_testmod.ko recompilation logic samples/bpf: Fix possible hang in xdpsock with multiple threads selftests/bpf: Make selftest compilation work on clang 11 selftests/bpf: Xsk selftests - adding xdpxceiver to .gitignore selftests/bpf: Drop tcp-{client,server}.py from Makefile selftests/bpf: Xsk selftests - Bi-directional Sockets - SKB, DRV selftests/bpf: Xsk selftests - Socket Teardown - SKB, DRV selftests/bpf: Xsk selftests - DRV POLL, NOPOLL selftests/bpf: Xsk selftests - SKB POLL, NOPOLL selftests/bpf: Xsk selftests framework bpf: Only provide bpf_sock_from_file with CONFIG_NET bpf: Return -ENOTSUPP when attaching to non-kernel BTF xsk: Validate socket state in xsk_recvmsg, prior touching socket members ... ==================== Link: https://lore.kernel.org/r/20201214214316.20642-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-11Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
xdp_return_frame_bulk() needs to pass a xdp_buff to __xdp_return(). strlcpy got converted to strscpy but here it makes no functional difference, so just keep the right code. Conflicts: net/netfilter/nf_tables_api.c Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-08xsk: Validate socket state in xsk_recvmsg, prior touching socket membersBjörn Töpel
In AF_XDP the socket state needs to be checked, prior touching the members of the socket. This was not the case for the recvmsg implementation. Fix that by moving the xsk_is_bound() call. Fixes: 45a86681844e ("xsk: Add support for recvmsg()") Reported-by: kernel test robot <oliver.sang@intel.com> Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Magnus Karlsson <magnus.karlsson@intel.com> Link: https://lore.kernel.org/bpf/20201207082008.132263-1-bjorn.topel@gmail.com
2020-12-04Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextJakub Kicinski
Alexei Starovoitov says: ==================== pull-request: bpf-next 2020-12-03 The main changes are: 1) Support BTF in kernel modules, from Andrii. 2) Introduce preferred busy-polling, from Björn. 3) bpf_ima_inode_hash() and bpf_bprm_opts_set() helpers, from KP Singh. 4) Memcg-based memory accounting for bpf objects, from Roman. 5) Allow bpf_{s,g}etsockopt from cgroup bind{4,6} hooks, from Stanislav. * https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (118 commits) selftests/bpf: Fix invalid use of strncat in test_sockmap libbpf: Use memcpy instead of strncpy to please GCC selftests/bpf: Add fentry/fexit/fmod_ret selftest for kernel module selftests/bpf: Add tp_btf CO-RE reloc test for modules libbpf: Support attachment of BPF tracing programs to kernel modules libbpf: Factor out low-level BPF program loading helper bpf: Allow to specify kernel module BTFs when attaching BPF programs bpf: Remove hard-coded btf_vmlinux assumption from BPF verifier selftests/bpf: Add CO-RE relocs selftest relying on kernel module BTF selftests/bpf: Add support for marking sub-tests as skipped selftests/bpf: Add bpf_testmod kernel module for testing libbpf: Add kernel module BTF support for CO-RE relocations libbpf: Refactor CO-RE relocs to not assume a single BTF object libbpf: Add internal helper to load BTF data by FD bpf: Keep module's btf_data_size intact after load bpf: Fix bpf_put_raw_tracepoint()'s use of __module_address() selftests/bpf: Add Userspace tests for TCP_WINDOW_CLAMP bpf: Adds support for setting window clamp samples/bpf: Fix spelling mistake "recieving" -> "receiving" bpf: Fix cold build of test_progs-no_alu32 ... ==================== Link: https://lore.kernel.org/r/20201204021936.85653-1-alexei.starovoitov@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-03xsk: Change the tx writeable conditionXuan Zhuo
Modify the tx writeable condition from the queue is not full to the number of present tx queues is less than the half of the total number of queues. Because the tx queue not full is a very short time, this will cause a large number of EPOLLOUT events, and cause a large number of process wake up. Fixes: 35fcde7f8deb ("xsk: support for Tx") Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Magnus Karlsson <magnus.karlsson@intel.com> Link: https://lore.kernel.org/bpf/508fef55188d4e1160747ead64c6dcda36735880.1606555939.git.xuanzhuo@linux.alibaba.com
2020-12-03xsk: Replace datagram_poll by sock_poll_waitXuan Zhuo
datagram_poll will judge the current socket status (EPOLLIN, EPOLLOUT) based on the traditional socket information (eg: sk_wmem_alloc), but this does not apply to xsk. So this patch uses sock_poll_wait instead of datagram_poll, and the mask is calculated by xsk_poll. Fixes: c497176cb2e4 ("xsk: add Rx receive functions and poll support") Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Magnus Karlsson <magnus.karlsson@intel.com> Link: https://lore.kernel.org/bpf/e82f4697438cd63edbf271ebe1918db8261b7c09.1606555939.git.xuanzhuo@linux.alibaba.com
2020-12-01xsk: Propagate napi_id to XDP socket Rx pathBjörn Töpel
Add napi_id to the xdp_rxq_info structure, and make sure the XDP socket pick up the napi_id in the Rx path. The napi_id is used to find the corresponding NAPI structure for socket busy polling. Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> Acked-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Tariq Toukan <tariqt@nvidia.com> Link: https://lore.kernel.org/bpf/20201130185205.196029-7-bjorn.topel@gmail.com
2020-12-01xsk: Add busy-poll support for {recv,send}msg()Björn Töpel
Wire-up XDP socket busy-poll support for recvmsg() and sendmsg(). If the XDP socket prefers busy-polling, make sure that no wakeup/IPI is performed. Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Magnus Karlsson <magnus.karlsson@intel.com> Link: https://lore.kernel.org/bpf/20201130185205.196029-6-bjorn.topel@gmail.com
2020-12-01xsk: Check need wakeup flag in sendmsg()Björn Töpel
Add a check for need wake up in sendmsg(), so that if a user calls sendmsg() when no wakeup is needed, do not trigger a wakeup. To simplify the need wakeup check in the syscall, unconditionally enable the need wakeup flag for Tx. This has a side-effect for poll(); If poll() is called for a socket without enabled need wakeup, a Tx wakeup is unconditionally performed. The wakeup matrix for AF_XDP now looks like: need wakeup | poll() | sendmsg() | recvmsg() ------------+--------------+-------------+------------ disabled | wake Tx | wake Tx | nop enabled | check flag; | check flag; | check flag; | wake Tx/Rx | wake Tx | wake Rx Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Magnus Karlsson <magnus.karlsson@intel.com> Link: https://lore.kernel.org/bpf/20201130185205.196029-5-bjorn.topel@gmail.com
2020-12-01xsk: Add support for recvmsg()Björn Töpel
Add support for non-blocking recvmsg() to XDP sockets. Previously, only sendmsg() was supported by XDP socket. Now, for symmetry and the upcoming busy-polling support, recvmsg() is added. Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Magnus Karlsson <magnus.karlsson@intel.com> Link: https://lore.kernel.org/bpf/20201130185205.196029-4-bjorn.topel@gmail.com
2020-11-27xdp: Remove the functions xsk_map_inc and xsk_map_putZhu Yanjun
The functions xsk_map_put() and xsk_map_inc() are simple wrappers and as such, replace these functions with the functions bpf_map_inc() and bpf_map_put() and remove some error testing code. Signed-off-by: Zhu Yanjun <zyjzyj2000@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Magnus Karlsson <magnus.karlsson@intel.com> Link: https://lore.kernel.org/bpf/1606402998-12562-1-git-send-email-yanjunz@nvidia.com
2020-11-24net, xsk: Avoid taking multiple skbuff referencesBjörn Töpel
Commit 642e450b6b59 ("xsk: Do not discard packet when NETDEV_TX_BUSY") addressed the problem that packets were discarded from the Tx AF_XDP ring, when the driver returned NETDEV_TX_BUSY. Part of the fix was bumping the skbuff reference count, so that the buffer would not be freed by dev_direct_xmit(). A reference count larger than one means that the skbuff is "shared", which is not the case. If the "shared" skbuff is sent to the generic XDP receive path, netif_receive_generic_xdp(), and pskb_expand_head() is entered the BUG_ON(skb_shared(skb)) will trigger. This patch adds a variant to dev_direct_xmit(), __dev_direct_xmit(), where a user can select the skbuff free policy. This allows AF_XDP to avoid bumping the reference count, but still keep the NETDEV_TX_BUSY behavior. Fixes: 642e450b6b59 ("xsk: Do not discard packet when NETDEV_TX_BUSY") Reported-by: Yonghong Song <yhs@fb.com> Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20201123175600.146255-1-bjorn.topel@gmail.com
2020-11-20xsk: Fix umem cleanup bug at socket destructMagnus Karlsson
Fix a bug that is triggered when a partially setup socket is destroyed. For a fully setup socket, a socket that has been bound to a device, the cleanup of the umem is performed at the end of the buffer pool's cleanup work queue item. This has to be performed in a work queue, and not in RCU cleanup, as it is doing a vunmap that cannot execute in interrupt context. However, when a socket has only been partially set up so that a umem has been created but the buffer pool has not, the code erroneously directly calls the umem cleanup function instead of using a work queue, and this leads to a BUG_ON() in vunmap(). As there in this case is no buffer pool, we cannot use its work queue, so we need to introduce a work queue for the umem and schedule this for the cleanup. So in the case there is no pool, we are going to use the umem's own work queue to schedule the cleanup. But if there is a pool, the cleanup of the umem is still being performed by the pool's work queue, as it is important that the umem is cleaned up after the pool. Fixes: e5e1a4bc916d ("xsk: Fix possible memory leak at socket close") Reported-by: Marek Majtyka <marekx.majtyka@intel.com> Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Marek Majtyka <marekx.majtyka@intel.com> Link: https://lore.kernel.org/bpf/1605873219-21629-1-git-send-email-magnus.karlsson@gmail.com
2020-11-17xsk: Introduce batched Tx descriptor interfacesMagnus Karlsson
Introduce batched descriptor interfaces in the xsk core code for the Tx path to be used in the driver to write a code path with higher performance. This interface will be used by the i40e driver in the next patch. Though other drivers would likely benefit from this new interface too. Note that batching is only implemented for the common case when there is only one socket bound to the same device and queue id. When this is not the case, we fall back to the old non-batched version of the function. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/1605525167-14450-5-git-send-email-magnus.karlsson@gmail.com
2020-10-29xsk: Fix possible memory leak at socket closeMagnus Karlsson
Fix a possible memory leak at xsk socket close that is caused by the refcounting of the umem object being wrong. The reference count of the umem was decremented only after the pool had been freed. Note that if the buffer pool is destroyed, it is important that the umem is destroyed after the pool, otherwise the umem would disappear while the driver is still running. And as the buffer pool needs to be destroyed in a work queue, the umem is also (if its refcount reaches zero) destroyed after the buffer pool in that same work queue. What was missing is that the refcount also needs to be decremented when the pool is not freed and when the pool has not even been created. The first case happens when the refcount of the pool is higher than 1, i.e. it is still being used by some other socket using the same device and queue id. In this case, it is safe to decrement the refcount of the umem outside of the work queue as the umem will never be freed because the refcount of the umem is always greater than or equal to the refcount of the buffer pool. The second case is if the buffer pool has not been created yet, i.e. the socket was closed before it was bound but after the umem was created. In this case, it is safe to destroy the umem outside of the work queue, since there is no pool that can use it by definition. Fixes: 1c1efc2af158 ("xsk: Create and free buffer pool independently from umem") Reported-by: syzbot+eb71df123dc2be2c1456@syzkaller.appspotmail.com Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Björn Töpel <bjorn.topel@intel.com> Link: https://lore.kernel.org/bpf/1603801921-2712-1-git-send-email-magnus.karlsson@gmail.com
2020-10-05Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller
Rejecting non-native endian BTF overlapped with the addition of support for it. The rest were more simple overlapping changes, except the renesas ravb binding update, which had to follow a file move as well as a YAML conversion. Signed-off-by: David S. Miller <davem@davemloft.net>