Dev queue af xdp upstream squash 2 #4
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Tell hardware to write back completed descriptors even when interrupts are disabled. Otherwise, descriptors might not be written back until the hardware can flush a full cacheline of descriptors. This can cause unnecessary delays when traffic is light (or even trigger Tx queue timeout). The example scenario to reproduce the Tx timeout if the fix is not applied: - configure at least 2 Tx queues to be assigned to the same q_vector, - generate a huge Tx traffic on the first Tx queue - try to send a few packets using the second Tx queue. In such a case Tx timeout will appear on the second Tx queue because no completion descriptors are written back for that queue while interrupts are disabled due to NAPI polling. The patch is necessary to start work on the AF_XDP implementation for the idpf driver, because there may be a case where a regular LAN Tx queue and an XDP queue share the same NAPI. Fixes: c2d548c ("idpf: add TX splitq napi poll support") Fixes: a5ab9ee ("idpf: add singleq start_xmit and napi poll") Reviewed-by: Przemek Kitszel <[email protected]> Reviewed-by: Alexander Lobakin <[email protected]> Signed-off-by: Joshua Hay <[email protected]> Co-developed-by: Michal Kubiak <[email protected]> Signed-off-by: Michal Kubiak <[email protected]>
The page pool feature allows for setting the page offset as a one of creation parameters. Such offset can be used for XDP-specific configuration of page pool when we need some extra space reserved for the packet headroom. Unfortunately, such page offset value (from the page pool) was never used during SKB build what can have a negative impact when XDP_PASS action is returned and the received packet should be passed to the kernel network stack. Address such a problem by adding the page offset from the page pool when SKB offset is being computed. Fixes: 3a8845a ("idpf: add RX splitq napi poll support") Signed-off-by: Michal Kubiak <[email protected]>
The IDPF driver supports the header split feature and that feature is always enabled by default. However, for flexibility reasons and to simplify the implementation of some features it would be useful to have the support for switching the header split off. Address that need by adding the user config parameter and the function for disabling (or enabling) the header split feature. Signed-off-by: Michal Kubiak <[email protected]>
Extend basic structures of the driver (e.g. 'idpf_vport', 'idpf_queue', 'idpf_vport_user_config_data') by adding members necessary to support XDP. Add extra XDP Tx queues needed to support XDP_TX and XDP_REDIRECT actions without interfering a regular Tx traffic. Also add functions dedicated to support XDP initialization for Rx and Tx queues and call those functions from the existing algorithms of queues configuration. Signed-off-by: Michal Kubiak <[email protected]>
Implement loading the XDP program using ndo_bpf callback for splitq and XDP_SETUP_PROG parameter. Add functions for stopping, reconfiguring and restarting all queues when needed. Also, implement the XDP hot swap mechanism when the existing XDP program is replaced by another one (without a necessity of reconfiguring anything). Signed-off-by: Michal Kubiak <[email protected]>
Implement basic setup of the XDP program. Extend the function for creating the page pool by adding a support for XDP headroom configuration. Add handling of XDP_PASS and XDP_DROP action. Signed-off-by: Michal Kubiak <[email protected]>
Implement two separate completion queue cleaning functions which should be used depending on the scheduling mode: - queue-based scheduling (idpf_tx_clean_qb_complq) - flow-based scheduling (idpf_tx_clean_fb_complq). Add 4-byte descriptor for queue-based scheduling mode and perform some refactoring to extract the common code for both scheduling modes. Signed-off-by: Michal Kubiak <[email protected]>
Implement sending the packet from an XDP ring. XDP path functions are separate from the general Tx routines, because this allows to simplify and therefore speedup the process. It also makes code more friendly to future XDP-specific optimizations Signed-off-by: Michal Kubiak <[email protected]>
Implement XDP_REDIRECT action and ndo_xdp_xmit() callback. For now, packets redirected from CPU with index greater than XDP queues number are just dropped with an error. This is a rather common situation and it will be addressed in later patches. Patch also refactors RX XDP handling to use switch statement due to increased number of actions. Signed-off-by: Michal Kubiak <[email protected]>
Port of commit 22bf877 ("ice: introduce XDP_TX fallback path"). The patch handles the case, when queue number is not sufficient for the current number of CPUs. To avoid dropping some packets redirected from other interfaces, XDP TxQs are allowed to be shared between CPUs, which imposes the locking requirement. Static key approach has little to none performance penalties when sharing is not needed. Suggested-by: Larysa Zaremba <[email protected]> Signed-off-by: Michal Kubiak <[email protected]>
Relative queue id is one of the required fields of the Tx queue description in VC 2.0 for splitq mode. In the current VC implementation all Tx queues are configured together, so the relative queue id (the index of the Tx queue in the queue group) can be computed on the fly. However, such a solution is not flexible because it is not easy to configure a single Tx queue. So, instead, introduce a new structure member in 'idpf_queue' dedicated to storing the relative queue id. Then send that value over the VC. This patch is the first step in making the existing VC API more flexible to allow configuration of single queues. Signed-off-by: Michal Kubiak <[email protected]>
Implement VC functions dedicated to enabling, disabling and configuring randomly selected queues. Also, refactor the existing implementation to make the code more modular. Introduce new generic functions for sending VC messages consisting of chunks, in order to isolate the sending algorithm and its implementation for specific VC messages. Finally, rewrite the function for mapping queues to q_vectors using the new modular approach to avoid copying the code that implements the VC message sending algorithm. Signed-off-by: Michal Kubiak <[email protected]>
Move Rx and Tx queue lookup functions from the ethtool implementation to the idpf header. Now, those functions can be used globally, including XDP configuration. Signed-off-by: Michal Kubiak <[email protected]>
Handle completion markers for idpf
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Andrii Nakryiko says: ==================== BPF verifier retval logic fixes This patch set fixes BPF verifier logic around validating and enforcing return values for BPF programs that have specific range of expected return values. Both sync and async callbacks have similar logic and are fixes as well. A few tests are added that would fail without the fixes in this patch set. Also, while at it, we update retval checking logic to use smin/smax range instead of tnum, avoiding future potential issues if expected range cannot be represented precisely by tnum (e.g., [0, 2] is not representable by tnum and is treated as [0, 3]). There is a little bit of refactoring to unify async callback and program exit logic to avoid duplication of checks as much as possible. v4->v5: - fix timer_bad_ret test on no-alu32 flavor (CI); v3->v4: - add back bpf_func_state rearrangement patch; - simplified patch #4 as suggested (Shung-Hsi); v2->v3: - more carefullly switch from umin/umax to smin/smax; v1->v2: - drop tnum from retval checks (Eduard); - use smin/smax instead of umin/umax (Alexei). ==================== Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
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Hou Tao says: ==================== bpf: Fix the release of inner map From: Hou Tao <[email protected]> Hi, The patchset aims to fix the release of inner map in map array or map htab. The release of inner map is different with normal map. For normal map, the map is released after the bpf program which uses the map is destroyed, because the bpf program tracks the used maps. However bpf program can not track the used inner map because these inner map may be updated or deleted dynamically, and for now the ref-counter of inner map is decreased after the inner map is remove from outer map, so the inner map may be freed before the bpf program, which is accessing the inner map, exits and there will be use-after-free problem as demonstrated by patch #6. The patchset fixes the problem by deferring the release of inner map. The freeing of inner map is deferred according to the sleepable attributes of the bpf programs which own the outer map. Patch #1 fixes the warning when running the newly-added selftest under interpreter mode. Patch #2 adds more parameters to .map_fd_put_ptr() to prepare for the fix. Patch #3 fixes the incorrect value of need_defer when freeing the fd array. Patch #4 fixes the potential use-after-free problem by using call_rcu_tasks_trace() and call_rcu() to wait for one tasks trace RCU GP and one RCU GP unconditionally. Patch #5 optimizes the free of inner map by removing the unnecessary RCU GP waiting. Patch #6 adds a selftest to demonstrate the potential use-after-free problem. Patch #7 updates a selftest to update outer map in syscall bpf program. Please see individual patches for more details. And comments are always welcome. Change Log: v5: * patch #3: rename fd_array_map_delete_elem_with_deferred_free() to __fd_array_map_delete_elem() (Alexei) * patch #5: use atomic64_t instead of atomic_t to prevent potential overflow (Alexei) * patch #7: use ptr_to_u64() helper instead of force casting to initialize pointers in bpf_attr (Alexei) v4: https://lore.kernel.org/bpf/[email protected] * patch #2: don't use "deferred", use "need_defer" uniformly * patch #3: newly-added, fix the incorrect value of need_defer during fd array free. * patch #4: doesn't consider the case in which bpf map is not used by any bpf program and only use sleepable_refcnt to remove unnecessary tasks trace RCU GP (Alexei) * patch #4: remove memory barriers added due to cautiousness (Alexei) v3: https://lore.kernel.org/bpf/[email protected] * multiple variable renamings (Martin) * define BPF_MAP_RCU_GP/BPF_MAP_RCU_TT_GP as bit (Martin) * use call_rcu() and its variants instead of synchronize_rcu() (Martin) * remove unnecessary mask in bpf_map_free_deferred() (Martin) * place atomic_or() and the related smp_mb() together (Martin) * add patch #6 to demonstrate that updating outer map in syscall program is dead-lock free (Alexei) * update comments about the memory barrier in bpf_map_fd_put_ptr() * update commit message for patch #3 and #4 to describe more details v2: https://lore.kernel.org/bpf/[email protected] * defer the invocation of ops->map_free() instead of bpf_map_put() (Martin) * update selftest to make it being reproducible under JIT mode (Martin) * remove unnecessary preparatory patches v1: https://lore.kernel.org/bpf/[email protected] ==================== Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
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Hou Tao says: ==================== The patch set aims to fix the problems found when inspecting the code related with maybe_wait_bpf_programs(). Patch #1 removes unnecessary invocation of maybe_wait_bpf_programs(). Patch #2 calls maybe_wait_bpf_programs() only once for batched update. Patch #3 adds the missed waiting when doing batched lookup_deletion on htab of maps. Patch #4 does wait only if the update or deletion operation succeeds. Patch #5 fixes the value of batch.count when memory allocation fails. ==================== Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
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Andrii Nakryiko says: ==================== BPF token support in libbpf's BPF object Add fuller support for BPF token in high-level BPF object APIs. This is the most frequently used way to work with BPF using libbpf, so supporting BPF token there is critical. Patch #1 is improving kernel-side BPF_TOKEN_CREATE behavior by rejecting to create "empty" BPF token with no delegation. This seems like saner behavior which also makes libbpf's caching better overall. If we ever want to create BPF token with no delegate_xxx options set on BPF FS, we can use a new flag to enable that. Patches #2-#5 refactor libbpf internals, mostly feature detection code, to prepare it from BPF token FD. Patch #6 adds options to pass BPF token into BPF object open options. It also adds implicit BPF token creation logic to BPF object load step, even without any explicit involvement of the user. If the environment is setup properly, BPF token will be created transparently and used implicitly. This allows for all existing application to gain BPF token support by just linking with latest version of libbpf library. No source code modifications are required. All that under assumption that privileged container management agent properly set up default BPF FS instance at /sys/bpf/fs to allow BPF token creation. Patches #7-#8 adds more selftests, validating BPF object APIs work as expected under unprivileged user namespaced conditions in the presence of BPF token. Patch alobakin#9 extends libbpf with LIBBPF_BPF_TOKEN_PATH envvar knowledge, which can be used to override custom BPF FS location used for implicit BPF token creation logic without needing to adjust application code. This allows admins or container managers to mount BPF token-enabled BPF FS at non-standard location without the need to coordinate with applications. LIBBPF_BPF_TOKEN_PATH can also be used to disable BPF token implicit creation by setting it to an empty value. Patch alobakin#10 tests this new envvar functionality. v2->v3: - move some stray feature cache refactorings into patch #4 (Alexei); - add LIBBPF_BPF_TOKEN_PATH envvar support (Alexei); v1->v2: - remove minor code redundancies (Eduard, John); - add acks and rebase. ==================== Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
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UBSAN reports the following 'subtraction overflow' error when booting in a virtual machine on Android: | Internal error: UBSAN: integer subtraction overflow: 00000000f2005515 [#1] PREEMPT SMP | Modules linked in: | CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.10.0-00006-g3cbe9e5abd46-dirty #4 | Hardware name: linux,dummy-virt (DT) | pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--) | pc : cancel_delayed_work+0x34/0x44 | lr : cancel_delayed_work+0x2c/0x44 | sp : ffff80008002ba60 | x29: ffff80008002ba60 x28: 0000000000000000 x27: 0000000000000000 | x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000000 | x23: 0000000000000000 x22: 0000000000000000 x21: ffff1f65014cd3c0 | x20: ffffc0e84c9d0da0 x19: ffffc0e84cab3558 x18: ffff800080009058 | x17: 00000000247ee1f8 x16: 00000000247ee1f8 x15: 00000000bdcb279d | x14: 0000000000000001 x13: 0000000000000075 x12: 00000a0000000000 | x11: ffff1f6501499018 x10: 00984901651fffff x9 : ffff5e7cc35af000 | x8 : 0000000000000001 x7 : 3d4d455453595342 x6 : 000000004e514553 | x5 : ffff1f6501499265 x4 : ffff1f650ff60b10 x3 : 0000000000000620 | x2 : ffff80008002ba78 x1 : 0000000000000000 x0 : 0000000000000000 | Call trace: | cancel_delayed_work+0x34/0x44 | deferred_probe_extend_timeout+0x20/0x70 | driver_register+0xa8/0x110 | __platform_driver_register+0x28/0x3c | syscon_init+0x24/0x38 | do_one_initcall+0xe4/0x338 | do_initcall_level+0xac/0x178 | do_initcalls+0x5c/0xa0 | do_basic_setup+0x20/0x30 | kernel_init_freeable+0x8c/0xf8 | kernel_init+0x28/0x1b4 | ret_from_fork+0x10/0x20 | Code: f9000fbf 97fffa2f 39400268 37100048 (d42aa2a0) | ---[ end trace 0000000000000000 ]--- | Kernel panic - not syncing: UBSAN: integer subtraction overflow: Fatal exception This is due to shift_and_mask() using a signed immediate to construct the mask and being called with a shift of 31 (WORK_OFFQ_POOL_SHIFT) so that it ends up decrementing from INT_MIN. Use an unsigned constant '1U' to generate the mask in shift_and_mask(). Cc: Tejun Heo <[email protected]> Cc: Lai Jiangshan <[email protected]> Fixes: 1211f3b ("workqueue: Preserve OFFQ bits in cancel[_sync] paths") Signed-off-by: Will Deacon <[email protected]> Signed-off-by: Tejun Heo <[email protected]>
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Lockdep reported a warning in Linux version 6.6: [ 414.344659] ================================ [ 414.345155] WARNING: inconsistent lock state [ 414.345658] 6.6.0-07439-gba2303cacfda #6 Not tainted [ 414.346221] -------------------------------- [ 414.346712] inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage. [ 414.347545] kworker/u10:3/1152 [HC0[0]:SC0[0]:HE0:SE1] takes: [ 414.349245] ffff88810edd1098 (&sbq->ws[i].wait){+.?.}-{2:2}, at: blk_mq_dispatch_rq_list+0x131c/0x1ee0 [ 414.351204] {IN-SOFTIRQ-W} state was registered at: [ 414.351751] lock_acquire+0x18d/0x460 [ 414.352218] _raw_spin_lock_irqsave+0x39/0x60 [ 414.352769] __wake_up_common_lock+0x22/0x60 [ 414.353289] sbitmap_queue_wake_up+0x375/0x4f0 [ 414.353829] sbitmap_queue_clear+0xdd/0x270 [ 414.354338] blk_mq_put_tag+0xdf/0x170 [ 414.354807] __blk_mq_free_request+0x381/0x4d0 [ 414.355335] blk_mq_free_request+0x28b/0x3e0 [ 414.355847] __blk_mq_end_request+0x242/0xc30 [ 414.356367] scsi_end_request+0x2c1/0x830 [ 414.345155] WARNING: inconsistent lock state [ 414.345658] 6.6.0-07439-gba2303cacfda #6 Not tainted [ 414.346221] -------------------------------- [ 414.346712] inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage. [ 414.347545] kworker/u10:3/1152 [HC0[0]:SC0[0]:HE0:SE1] takes: [ 414.349245] ffff88810edd1098 (&sbq->ws[i].wait){+.?.}-{2:2}, at: blk_mq_dispatch_rq_list+0x131c/0x1ee0 [ 414.351204] {IN-SOFTIRQ-W} state was registered at: [ 414.351751] lock_acquire+0x18d/0x460 [ 414.352218] _raw_spin_lock_irqsave+0x39/0x60 [ 414.352769] __wake_up_common_lock+0x22/0x60 [ 414.353289] sbitmap_queue_wake_up+0x375/0x4f0 [ 414.353829] sbitmap_queue_clear+0xdd/0x270 [ 414.354338] blk_mq_put_tag+0xdf/0x170 [ 414.354807] __blk_mq_free_request+0x381/0x4d0 [ 414.355335] blk_mq_free_request+0x28b/0x3e0 [ 414.355847] __blk_mq_end_request+0x242/0xc30 [ 414.356367] scsi_end_request+0x2c1/0x830 [ 414.356863] scsi_io_completion+0x177/0x1610 [ 414.357379] scsi_complete+0x12f/0x260 [ 414.357856] blk_complete_reqs+0xba/0xf0 [ 414.358338] __do_softirq+0x1b0/0x7a2 [ 414.358796] irq_exit_rcu+0x14b/0x1a0 [ 414.359262] sysvec_call_function_single+0xaf/0xc0 [ 414.359828] asm_sysvec_call_function_single+0x1a/0x20 [ 414.360426] default_idle+0x1e/0x30 [ 414.360873] default_idle_call+0x9b/0x1f0 [ 414.361390] do_idle+0x2d2/0x3e0 [ 414.361819] cpu_startup_entry+0x55/0x60 [ 414.362314] start_secondary+0x235/0x2b0 [ 414.362809] secondary_startup_64_no_verify+0x18f/0x19b [ 414.363413] irq event stamp: 428794 [ 414.363825] hardirqs last enabled at (428793): [<ffffffff816bfd1c>] ktime_get+0x1dc/0x200 [ 414.364694] hardirqs last disabled at (428794): [<ffffffff85470177>] _raw_spin_lock_irq+0x47/0x50 [ 414.365629] softirqs last enabled at (428444): [<ffffffff85474780>] __do_softirq+0x540/0x7a2 [ 414.366522] softirqs last disabled at (428419): [<ffffffff813f65ab>] irq_exit_rcu+0x14b/0x1a0 [ 414.367425] other info that might help us debug this: [ 414.368194] Possible unsafe locking scenario: [ 414.368900] CPU0 [ 414.369225] ---- [ 414.369548] lock(&sbq->ws[i].wait); [ 414.370000] <Interrupt> [ 414.370342] lock(&sbq->ws[i].wait); [ 414.370802] *** DEADLOCK *** [ 414.371569] 5 locks held by kworker/u10:3/1152: [ 414.372088] #0: ffff88810130e938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x357/0x13f0 [ 414.373180] #1: ffff88810201fdb8 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x3a3/0x13f0 [ 414.374384] #2: ffffffff86ffbdc0 (rcu_read_lock){....}-{1:2}, at: blk_mq_run_hw_queue+0x637/0xa00 [ 414.375342] #3: ffff88810edd1098 (&sbq->ws[i].wait){+.?.}-{2:2}, at: blk_mq_dispatch_rq_list+0x131c/0x1ee0 [ 414.376377] #4: ffff888106205a08 (&hctx->dispatch_wait_lock){+.-.}-{2:2}, at: blk_mq_dispatch_rq_list+0x1337/0x1ee0 [ 414.378607] stack backtrace: [ 414.379177] CPU: 0 PID: 1152 Comm: kworker/u10:3 Not tainted 6.6.0-07439-gba2303cacfda #6 [ 414.380032] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [ 414.381177] Workqueue: writeback wb_workfn (flush-253:0) [ 414.381805] Call Trace: [ 414.382136] <TASK> [ 414.382429] dump_stack_lvl+0x91/0xf0 [ 414.382884] mark_lock_irq+0xb3b/0x1260 [ 414.383367] ? __pfx_mark_lock_irq+0x10/0x10 [ 414.383889] ? stack_trace_save+0x8e/0xc0 [ 414.384373] ? __pfx_stack_trace_save+0x10/0x10 [ 414.384903] ? graph_lock+0xcf/0x410 [ 414.385350] ? save_trace+0x3d/0xc70 [ 414.385808] mark_lock.part.20+0x56d/0xa90 [ 414.386317] mark_held_locks+0xb0/0x110 [ 414.386791] ? __pfx_do_raw_spin_lock+0x10/0x10 [ 414.387320] lockdep_hardirqs_on_prepare+0x297/0x3f0 [ 414.387901] ? _raw_spin_unlock_irq+0x28/0x50 [ 414.388422] trace_hardirqs_on+0x58/0x100 [ 414.388917] _raw_spin_unlock_irq+0x28/0x50 [ 414.389422] __blk_mq_tag_busy+0x1d6/0x2a0 [ 414.389920] __blk_mq_get_driver_tag+0x761/0x9f0 [ 414.390899] blk_mq_dispatch_rq_list+0x1780/0x1ee0 [ 414.391473] ? __pfx_blk_mq_dispatch_rq_list+0x10/0x10 [ 414.392070] ? sbitmap_get+0x2b8/0x450 [ 414.392533] ? __blk_mq_get_driver_tag+0x210/0x9f0 [ 414.393095] __blk_mq_sched_dispatch_requests+0xd99/0x1690 [ 414.393730] ? elv_attempt_insert_merge+0x1b1/0x420 [ 414.394302] ? __pfx___blk_mq_sched_dispatch_requests+0x10/0x10 [ 414.394970] ? lock_acquire+0x18d/0x460 [ 414.395456] ? blk_mq_run_hw_queue+0x637/0xa00 [ 414.395986] ? __pfx_lock_acquire+0x10/0x10 [ 414.396499] blk_mq_sched_dispatch_requests+0x109/0x190 [ 414.397100] blk_mq_run_hw_queue+0x66e/0xa00 [ 414.397616] blk_mq_flush_plug_list.part.17+0x614/0x2030 [ 414.398244] ? __pfx_blk_mq_flush_plug_list.part.17+0x10/0x10 [ 414.398897] ? writeback_sb_inodes+0x241/0xcc0 [ 414.399429] blk_mq_flush_plug_list+0x65/0x80 [ 414.399957] __blk_flush_plug+0x2f1/0x530 [ 414.400458] ? __pfx___blk_flush_plug+0x10/0x10 [ 414.400999] blk_finish_plug+0x59/0xa0 [ 414.401467] wb_writeback+0x7cc/0x920 [ 414.401935] ? __pfx_wb_writeback+0x10/0x10 [ 414.402442] ? mark_held_locks+0xb0/0x110 [ 414.402931] ? __pfx_do_raw_spin_lock+0x10/0x10 [ 414.403462] ? lockdep_hardirqs_on_prepare+0x297/0x3f0 [ 414.404062] wb_workfn+0x2b3/0xcf0 [ 414.404500] ? __pfx_wb_workfn+0x10/0x10 [ 414.404989] process_scheduled_works+0x432/0x13f0 [ 414.405546] ? __pfx_process_scheduled_works+0x10/0x10 [ 414.406139] ? do_raw_spin_lock+0x101/0x2a0 [ 414.406641] ? assign_work+0x19b/0x240 [ 414.407106] ? lock_is_held_type+0x9d/0x110 [ 414.407604] worker_thread+0x6f2/0x1160 [ 414.408075] ? __kthread_parkme+0x62/0x210 [ 414.408572] ? lockdep_hardirqs_on_prepare+0x297/0x3f0 [ 414.409168] ? __kthread_parkme+0x13c/0x210 [ 414.409678] ? __pfx_worker_thread+0x10/0x10 [ 414.410191] kthread+0x33c/0x440 [ 414.410602] ? __pfx_kthread+0x10/0x10 [ 414.411068] ret_from_fork+0x4d/0x80 [ 414.411526] ? __pfx_kthread+0x10/0x10 [ 414.411993] ret_from_fork_asm+0x1b/0x30 [ 414.412489] </TASK> When interrupt is turned on while a lock holding by spin_lock_irq it throws a warning because of potential deadlock. blk_mq_prep_dispatch_rq blk_mq_get_driver_tag __blk_mq_get_driver_tag __blk_mq_alloc_driver_tag blk_mq_tag_busy -> tag is already busy // failed to get driver tag blk_mq_mark_tag_wait spin_lock_irq(&wq->lock) -> lock A (&sbq->ws[i].wait) __add_wait_queue(wq, wait) -> wait queue active blk_mq_get_driver_tag __blk_mq_tag_busy -> 1) tag must be idle, which means there can't be inflight IO spin_lock_irq(&tags->lock) -> lock B (hctx->tags) spin_unlock_irq(&tags->lock) -> unlock B, turn on interrupt accidentally -> 2) context must be preempt by IO interrupt to trigger deadlock. As shown above, the deadlock is not possible in theory, but the warning still need to be fixed. Fix it by using spin_lock_irqsave to get lockB instead of spin_lock_irq. Fixes: 4f1731d ("blk-mq: fix potential io hang by wrong 'wake_batch'") Signed-off-by: Li Lingfeng <[email protected]> Reviewed-by: Ming Lei <[email protected]> Reviewed-by: Yu Kuai <[email protected]> Reviewed-by: Bart Van Assche <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jens Axboe <[email protected]>
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…rnel/git/netfilter/nf-next Pablo Neira Ayuso says: ==================== Netfilter updates for net-next The following batch contains Netfilter updates for net-next: Patch #1 fix checksum calculation in nfnetlink_queue with SCTP, segment GSO packet since skb_zerocopy() does not support GSO_BY_FRAGS, from Antonio Ojea. Patch #2 extend nfnetlink_queue coverage to handle SCTP packets, from Antonio Ojea. Patch #3 uses consume_skb() instead of kfree_skb() in nfnetlink, from Donald Hunter. Patch #4 adds a dedicate commit list for sets to speed up intra-transaction lookups, from Florian Westphal. Patch #5 skips removal of element from abort path for the pipapo backend, ditching the shadow copy of this datastructure is sufficient. Patch #6 moves nf_ct_netns_get() out of nf_conncount_init() to let users of conncoiunt decide when to enable conntrack, this is needed by openvswitch, from Xin Long. Patch #7 pass context to all nft_parse_register_load() in preparation for the next patch. Patches #8 and alobakin#9 reject loads from uninitialized registers from control plane to remove register initialization from datapath. From Florian Westphal. * tag 'nf-next-24-08-23' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next: netfilter: nf_tables: don't initialize registers in nft_do_chain() netfilter: nf_tables: allow loads only when register is initialized netfilter: nf_tables: pass context structure to nft_parse_register_load netfilter: move nf_ct_netns_get out of nf_conncount_init netfilter: nf_tables: do not remove elements if set backend implements .abort netfilter: nf_tables: store new sets in dedicated list netfilter: nfnetlink: convert kfree_skb to consume_skb selftests: netfilter: nft_queue.sh: sctp coverage netfilter: nfnetlink_queue: unbreak SCTP traffic ==================== Link: https://patch.msgid.link/[email protected] Signed-off-by: Jakub Kicinski <[email protected]>
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Ido Schimmel says:
====================
Unmask upper DSCP bits - part 2
tl;dr - This patchset continues to unmask the upper DSCP bits in the
IPv4 flow key in preparation for allowing IPv4 FIB rules to match on
DSCP. No functional changes are expected. Part 1 was merged in commit
("Merge branch 'unmask-upper-dscp-bits-part-1'").
The TOS field in the IPv4 flow key ('flowi4_tos') is used during FIB
lookup to match against the TOS selector in FIB rules and routes.
It is currently impossible for user space to configure FIB rules that
match on the DSCP value as the upper DSCP bits are either masked in the
various call sites that initialize the IPv4 flow key or along the path
to the FIB core.
In preparation for adding a DSCP selector to IPv4 and IPv6 FIB rules, we
need to make sure the entire DSCP value is present in the IPv4 flow key.
This patchset continues to unmask the upper DSCP bits, but this time in
the output route path.
Patches #1-#3 unmask the upper DSCP bits in the various places that
invoke the core output route lookup functions directly.
Patches #4-#6 do the same in three helpers that are widely used in the
output path to initialize the TOS field in the IPv4 flow key.
The rest of the patches continue to unmask these bits in call sites that
invoke the following wrappers around the core lookup functions:
Patch #7 - __ip_route_output_key()
Patches #8-alobakin#12 - ip_route_output_flow()
The next patchset will handle the callers of ip_route_output_ports() and
ip_route_output_key().
No functional changes are expected as commit 1fa3314 ("ipv4:
Centralize TOS matching") moved the masking of the upper DSCP bits to
the core where 'flowi4_tos' is matched against the TOS selector.
Changes since v1 [1]:
* Remove IPTOS_RT_MASK in patch #7 instead of in patch #6
[1] https://lore.kernel.org/netdev/[email protected]/
====================
Signed-off-by: David S. Miller <[email protected]>
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When using cachefiles, lockdep may emit something similar to the circular
locking dependency notice below. The problem appears to stem from the
following:
(1) Cachefiles manipulates xattrs on the files in its cache when called
from ->writepages().
(2) The setxattr() and removexattr() system call handlers get the name
(and value) from userspace after taking the sb_writers lock, putting
accesses of the vma->vm_lock and mm->mmap_lock inside of that.
(3) The afs filesystem uses a per-inode lock to prevent multiple
revalidation RPCs and in writeback vs truncate to prevent parallel
operations from deadlocking against the server on one side and local
page locks on the other.
Fix this by moving the getting of the name and value in {get,remove}xattr()
outside of the sb_writers lock. This also has the minor benefits that we
don't need to reget these in the event of a retry and we never try to take
the sb_writers lock in the event we can't pull the name and value into the
kernel.
Alternative approaches that might fix this include moving the dispatch of a
write to the cache off to a workqueue or trying to do without the
validation lock in afs. Note that this might also affect other filesystems
that use netfslib and/or cachefiles.
======================================================
WARNING: possible circular locking dependency detected
6.10.0-build2+ torvalds#956 Not tainted
------------------------------------------------------
fsstress/6050 is trying to acquire lock:
ffff888138fd82f0 (mapping.invalidate_lock#3){++++}-{3:3}, at: filemap_fault+0x26e/0x8b0
but task is already holding lock:
ffff888113f26d18 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x165/0x250
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #4 (&vma->vm_lock->lock){++++}-{3:3}:
__lock_acquire+0xaf0/0xd80
lock_acquire.part.0+0x103/0x280
down_write+0x3b/0x50
vma_start_write+0x6b/0xa0
vma_link+0xcc/0x140
insert_vm_struct+0xb7/0xf0
alloc_bprm+0x2c1/0x390
kernel_execve+0x65/0x1a0
call_usermodehelper_exec_async+0x14d/0x190
ret_from_fork+0x24/0x40
ret_from_fork_asm+0x1a/0x30
-> #3 (&mm->mmap_lock){++++}-{3:3}:
__lock_acquire+0xaf0/0xd80
lock_acquire.part.0+0x103/0x280
__might_fault+0x7c/0xb0
strncpy_from_user+0x25/0x160
removexattr+0x7f/0x100
__do_sys_fremovexattr+0x7e/0xb0
do_syscall_64+0x9f/0x100
entry_SYSCALL_64_after_hwframe+0x76/0x7e
-> #2 (sb_writers#14){.+.+}-{0:0}:
__lock_acquire+0xaf0/0xd80
lock_acquire.part.0+0x103/0x280
percpu_down_read+0x3c/0x90
vfs_iocb_iter_write+0xe9/0x1d0
__cachefiles_write+0x367/0x430
cachefiles_issue_write+0x299/0x2f0
netfs_advance_write+0x117/0x140
netfs_write_folio.isra.0+0x5ca/0x6e0
netfs_writepages+0x230/0x2f0
afs_writepages+0x4d/0x70
do_writepages+0x1e8/0x3e0
filemap_fdatawrite_wbc+0x84/0xa0
__filemap_fdatawrite_range+0xa8/0xf0
file_write_and_wait_range+0x59/0x90
afs_release+0x10f/0x270
__fput+0x25f/0x3d0
__do_sys_close+0x43/0x70
do_syscall_64+0x9f/0x100
entry_SYSCALL_64_after_hwframe+0x76/0x7e
-> #1 (&vnode->validate_lock){++++}-{3:3}:
__lock_acquire+0xaf0/0xd80
lock_acquire.part.0+0x103/0x280
down_read+0x95/0x200
afs_writepages+0x37/0x70
do_writepages+0x1e8/0x3e0
filemap_fdatawrite_wbc+0x84/0xa0
filemap_invalidate_inode+0x167/0x1e0
netfs_unbuffered_write_iter+0x1bd/0x2d0
vfs_write+0x22e/0x320
ksys_write+0xbc/0x130
do_syscall_64+0x9f/0x100
entry_SYSCALL_64_after_hwframe+0x76/0x7e
-> #0 (mapping.invalidate_lock#3){++++}-{3:3}:
check_noncircular+0x119/0x160
check_prev_add+0x195/0x430
__lock_acquire+0xaf0/0xd80
lock_acquire.part.0+0x103/0x280
down_read+0x95/0x200
filemap_fault+0x26e/0x8b0
__do_fault+0x57/0xd0
do_pte_missing+0x23b/0x320
__handle_mm_fault+0x2d4/0x320
handle_mm_fault+0x14f/0x260
do_user_addr_fault+0x2a2/0x500
exc_page_fault+0x71/0x90
asm_exc_page_fault+0x22/0x30
other info that might help us debug this:
Chain exists of:
mapping.invalidate_lock#3 --> &mm->mmap_lock --> &vma->vm_lock->lock
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
rlock(&vma->vm_lock->lock);
lock(&mm->mmap_lock);
lock(&vma->vm_lock->lock);
rlock(mapping.invalidate_lock#3);
*** DEADLOCK ***
1 lock held by fsstress/6050:
#0: ffff888113f26d18 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x165/0x250
stack backtrace:
CPU: 0 PID: 6050 Comm: fsstress Not tainted 6.10.0-build2+ torvalds#956
Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014
Call Trace:
<TASK>
dump_stack_lvl+0x57/0x80
check_noncircular+0x119/0x160
? queued_spin_lock_slowpath+0x4be/0x510
? __pfx_check_noncircular+0x10/0x10
? __pfx_queued_spin_lock_slowpath+0x10/0x10
? mark_lock+0x47/0x160
? init_chain_block+0x9c/0xc0
? add_chain_block+0x84/0xf0
check_prev_add+0x195/0x430
__lock_acquire+0xaf0/0xd80
? __pfx___lock_acquire+0x10/0x10
? __lock_release.isra.0+0x13b/0x230
lock_acquire.part.0+0x103/0x280
? filemap_fault+0x26e/0x8b0
? __pfx_lock_acquire.part.0+0x10/0x10
? rcu_is_watching+0x34/0x60
? lock_acquire+0xd7/0x120
down_read+0x95/0x200
? filemap_fault+0x26e/0x8b0
? __pfx_down_read+0x10/0x10
? __filemap_get_folio+0x25/0x1a0
filemap_fault+0x26e/0x8b0
? __pfx_filemap_fault+0x10/0x10
? find_held_lock+0x7c/0x90
? __pfx___lock_release.isra.0+0x10/0x10
? __pte_offset_map+0x99/0x110
__do_fault+0x57/0xd0
do_pte_missing+0x23b/0x320
__handle_mm_fault+0x2d4/0x320
? __pfx___handle_mm_fault+0x10/0x10
handle_mm_fault+0x14f/0x260
do_user_addr_fault+0x2a2/0x500
exc_page_fault+0x71/0x90
asm_exc_page_fault+0x22/0x30
Signed-off-by: David Howells <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
cc: Alexander Viro <[email protected]>
cc: Christian Brauner <[email protected]>
cc: Jan Kara <[email protected]>
cc: Jeff Layton <[email protected]>
cc: Gao Xiang <[email protected]>
cc: Matthew Wilcox <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
[brauner: fix minor issues]
Signed-off-by: Christian Brauner <[email protected]>
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Use raw_spinlock in order to fix spurious messages about invalid context
when spinlock debugging is enabled. The lock is only used to serialize
register access.
[ 4.239592] =============================
[ 4.239595] [ BUG: Invalid wait context ]
[ 4.239599] 6.13.0-rc7-arm64-renesas-05496-gd088502a519f torvalds#35 Not tainted
[ 4.239603] -----------------------------
[ 4.239606] kworker/u8:5/76 is trying to lock:
[ 4.239609] ffff0000091898a0 (&p->lock){....}-{3:3}, at: gpio_rcar_config_interrupt_input_mode+0x34/0x164
[ 4.239641] other info that might help us debug this:
[ 4.239643] context-{5:5}
[ 4.239646] 5 locks held by kworker/u8:5/76:
[ 4.239651] #0: ffff0000080fb148 ((wq_completion)async){+.+.}-{0:0}, at: process_one_work+0x190/0x62c
[ 4.250180] OF: /soc/sound@ec500000/ports/port@0/endpoint: Read of boolean property 'frame-master' with a value.
[ 4.254094] #1: ffff80008299bd80 ((work_completion)(&entry->work)){+.+.}-{0:0}, at: process_one_work+0x1b8/0x62c
[ 4.254109] #2: ffff00000920c8f8
[ 4.258345] OF: /soc/sound@ec500000/ports/port@1/endpoint: Read of boolean property 'bitclock-master' with a value.
[ 4.264803] (&dev->mutex){....}-{4:4}, at: __device_attach_async_helper+0x3c/0xdc
[ 4.264820] #3: ffff00000a50ca40 (request_class#2){+.+.}-{4:4}, at: __setup_irq+0xa0/0x690
[ 4.264840] #4:
[ 4.268872] OF: /soc/sound@ec500000/ports/port@1/endpoint: Read of boolean property 'frame-master' with a value.
[ 4.273275] ffff00000a50c8c8 (lock_class){....}-{2:2}, at: __setup_irq+0xc4/0x690
[ 4.296130] renesas_sdhi_internal_dmac ee100000.mmc: mmc1 base at 0x00000000ee100000, max clock rate 200 MHz
[ 4.304082] stack backtrace:
[ 4.304086] CPU: 1 UID: 0 PID: 76 Comm: kworker/u8:5 Not tainted 6.13.0-rc7-arm64-renesas-05496-gd088502a519f torvalds#35
[ 4.304092] Hardware name: Renesas Salvator-X 2nd version board based on r8a77965 (DT)
[ 4.304097] Workqueue: async async_run_entry_fn
[ 4.304106] Call trace:
[ 4.304110] show_stack+0x14/0x20 (C)
[ 4.304122] dump_stack_lvl+0x6c/0x90
[ 4.304131] dump_stack+0x14/0x1c
[ 4.304138] __lock_acquire+0xdfc/0x1584
[ 4.426274] lock_acquire+0x1c4/0x33c
[ 4.429942] _raw_spin_lock_irqsave+0x5c/0x80
[ 4.434307] gpio_rcar_config_interrupt_input_mode+0x34/0x164
[ 4.440061] gpio_rcar_irq_set_type+0xd4/0xd8
[ 4.444422] __irq_set_trigger+0x5c/0x178
[ 4.448435] __setup_irq+0x2e4/0x690
[ 4.452012] request_threaded_irq+0xc4/0x190
[ 4.456285] devm_request_threaded_irq+0x7c/0xf4
[ 4.459398] ata1: link resume succeeded after 1 retries
[ 4.460902] mmc_gpiod_request_cd_irq+0x68/0xe0
[ 4.470660] mmc_start_host+0x50/0xac
[ 4.474327] mmc_add_host+0x80/0xe4
[ 4.477817] tmio_mmc_host_probe+0x2b0/0x440
[ 4.482094] renesas_sdhi_probe+0x488/0x6f4
[ 4.486281] renesas_sdhi_internal_dmac_probe+0x60/0x78
[ 4.491509] platform_probe+0x64/0xd8
[ 4.495178] really_probe+0xb8/0x2a8
[ 4.498756] __driver_probe_device+0x74/0x118
[ 4.503116] driver_probe_device+0x3c/0x154
[ 4.507303] __device_attach_driver+0xd4/0x160
[ 4.511750] bus_for_each_drv+0x84/0xe0
[ 4.515588] __device_attach_async_helper+0xb0/0xdc
[ 4.520470] async_run_entry_fn+0x30/0xd8
[ 4.524481] process_one_work+0x210/0x62c
[ 4.528494] worker_thread+0x1ac/0x340
[ 4.532245] kthread+0x10c/0x110
[ 4.535476] ret_from_fork+0x10/0x20
Signed-off-by: Niklas Söderlund <[email protected]>
Reviewed-by: Geert Uytterhoeven <[email protected]>
Tested-by: Geert Uytterhoeven <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Bartosz Golaszewski <[email protected]>
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…/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 fixes for 6.14, take #4 - Fix a couple of bugs affecting pKVM's PSCI relay implementation when running in the hVHE mode, resulting in the host being entered with the MMU in an unknown state, and EL2 being in the wrong mode.
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Chia-Yu Chang says: ==================== AccECN protocol preparation patch series Please find the v7 v7 (03-Mar-2025) - Move 2 new patches added in v6 to the next AccECN patch series v6 (27-Dec-2024) - Avoid removing removing the potential CA_ACK_WIN_UPDATE in ack_ev_flags of patch #1 (Eric Dumazet <[email protected]>) - Add reviewed-by tag in patches #2, #3, #4, #5, #6, #7, #8, alobakin#12, alobakin#14 - Foloiwng 2 new pathces are added after patch alobakin#9 (Patch that adds SKB_GSO_TCP_ACCECN) * New patch alobakin#10 to replace exisiting SKB_GSO_TCP_ECN with SKB_GSO_TCP_ACCECN in the driver to avoid CWR flag corruption * New patch alobakin#11 adds AccECN for virtio by adding new negotiation flag (VIRTIO_NET_F_HOST/GUEST_ACCECN) in feature handshake and translating Accurate ECN GSO flag between virtio_net_hdr (VIRTIO_NET_HDR_GSO_ACCECN) and skb header (SKB_GSO_TCP_ACCECN) - Add detailed changelog and comments in alobakin#13 (Eric Dumazet <[email protected]>) - Move patch alobakin#14 to the next AccECN patch series (Eric Dumazet <[email protected]>) v5 (5-Nov-2024) - Add helper function "tcp_flags_ntohs" to preserve last 2 bytes of TCP flags of patch #4 (Paolo Abeni <[email protected]>) - Fix reverse X-max tree order of patches #4, alobakin#11 (Paolo Abeni <[email protected]>) - Rename variable "delta" as "timestamp_delta" of patch #2 fo clariety - Remove patch alobakin#14 in this series (Paolo Abeni <[email protected]>, Joel Granados <[email protected]>) v4 (21-Oct-2024) - Fix line length warning of patches #2, #4, #8, alobakin#10, alobakin#11, alobakin#14 - Fix spaces preferred around '|' (ctx:VxV) warning of patch #7 - Add missing CC'ed of patches #4, alobakin#12, alobakin#14 v3 (19-Oct-2024) - Fix build error in v2 v2 (18-Oct-2024) - Fix warning caused by NETIF_F_GSO_ACCECN_BIT in patch alobakin#9 (Jakub Kicinski <[email protected]>) The full patch series can be found in https://github.com/L4STeam/linux-net-next/commits/upstream_l4steam/ The Accurate ECN draft can be found in https://datatracker.ietf.org/doc/html/draft-ietf-tcpm-accurate-ecn-28 ==================== Signed-off-by: David S. Miller <[email protected]>
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…cal section
A circular lock dependency splat has been seen involving down_trylock():
======================================================
WARNING: possible circular locking dependency detected
6.12.0-41.el10.s390x+debug
------------------------------------------------------
dd/32479 is trying to acquire lock:
0015a20accd0d4f8 ((console_sem).lock){-.-.}-{2:2}, at: down_trylock+0x26/0x90
but task is already holding lock:
000000017e461698 (&zone->lock){-.-.}-{2:2}, at: rmqueue_bulk+0xac/0x8f0
the existing dependency chain (in reverse order) is:
-> #4 (&zone->lock){-.-.}-{2:2}:
-> #3 (hrtimer_bases.lock){-.-.}-{2:2}:
-> #2 (&rq->__lock){-.-.}-{2:2}:
-> #1 (&p->pi_lock){-.-.}-{2:2}:
-> #0 ((console_sem).lock){-.-.}-{2:2}:
The console_sem -> pi_lock dependency is due to calling try_to_wake_up()
while holding the console_sem raw_spinlock. This dependency can be broken
by using wake_q to do the wakeup instead of calling try_to_wake_up()
under the console_sem lock. This will also make the semaphore's
raw_spinlock become a terminal lock without taking any further locks
underneath it.
The hrtimer_bases.lock is a raw_spinlock while zone->lock is a
spinlock. The hrtimer_bases.lock -> zone->lock dependency happens via
the debug_objects_fill_pool() helper function in the debugobjects code.
-> #4 (&zone->lock){-.-.}-{2:2}:
__lock_acquire+0xe86/0x1cc0
lock_acquire.part.0+0x258/0x630
lock_acquire+0xb8/0xe0
_raw_spin_lock_irqsave+0xb4/0x120
rmqueue_bulk+0xac/0x8f0
__rmqueue_pcplist+0x580/0x830
rmqueue_pcplist+0xfc/0x470
rmqueue.isra.0+0xdec/0x11b0
get_page_from_freelist+0x2ee/0xeb0
__alloc_pages_noprof+0x2c2/0x520
alloc_pages_mpol_noprof+0x1fc/0x4d0
alloc_pages_noprof+0x8c/0xe0
allocate_slab+0x320/0x460
___slab_alloc+0xa58/0x12b0
__slab_alloc.isra.0+0x42/0x60
kmem_cache_alloc_noprof+0x304/0x350
fill_pool+0xf6/0x450
debug_object_activate+0xfe/0x360
enqueue_hrtimer+0x34/0x190
__run_hrtimer+0x3c8/0x4c0
__hrtimer_run_queues+0x1b2/0x260
hrtimer_interrupt+0x316/0x760
do_IRQ+0x9a/0xe0
do_irq_async+0xf6/0x160
Normally a raw_spinlock to spinlock dependency is not legitimate
and will be warned if CONFIG_PROVE_RAW_LOCK_NESTING is enabled,
but debug_objects_fill_pool() is an exception as it explicitly
allows this dependency for non-PREEMPT_RT kernel without causing
PROVE_RAW_LOCK_NESTING lockdep splat. As a result, this dependency is
legitimate and not a bug.
Anyway, semaphore is the only locking primitive left that is still
using try_to_wake_up() to do wakeup inside critical section, all the
other locking primitives had been migrated to use wake_q to do wakeup
outside of the critical section. It is also possible that there are
other circular locking dependencies involving printk/console_sem or
other existing/new semaphores lurking somewhere which may show up in
the future. Let just do the migration now to wake_q to avoid headache
like this.
Reported-by: [email protected]
Signed-off-by: Waiman Long <[email protected]>
Signed-off-by: Boqun Feng <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Cc: Linus Torvalds <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
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Tariq Toukan says: ==================== mlx5e: Support recovery counter in reset This series by Yael adds a recovery counter in ethtool, for any recovery type during port reset cycle. Series starts with some cleanup and refactoring patches. New counter is added and exposed to ethtool stats in patch #4. ==================== Link: https://patch.msgid.link/[email protected] Signed-off-by: Paolo Abeni <[email protected]>
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Mar 27, 2025
…-bridge-ports'
Petr Machata says:
====================
mlxsw: Add VXLAN to the same hardware domain as physical bridge ports
Amit Cohen writes:
Packets which are trapped to CPU for forwarding in software data path
are handled according to driver marking of skb->offload_{,l3}_fwd_mark.
Packets which are marked as L2-forwarded in hardware, will not be flooded
by the bridge to bridge ports which are in the same hardware domain as the
ingress port.
Currently, mlxsw does not add VXLAN bridge ports to the same hardware
domain as physical bridge ports despite the fact that the device is able
to forward packets to and from VXLAN tunnels in hardware. In some
scenarios this can result in remote VTEPs receiving duplicate packets.
To solve such packets duplication, add VXLAN bridge ports to the same
hardware domain as other bridge ports.
One complication is ARP suppression which requires the local VTEP to avoid
flooding ARP packets to remote VTEPs if the local VTEP is able to reply on
behalf of remote hosts. This is currently implemented by having the device
flood ARP packets in hardware and trapping them during VXLAN encapsulation,
but marking them with skb->offload_fwd_mark=1 so that the bridge will not
re-flood them to physical bridge ports.
The above scheme will break when VXLAN bridge ports are added to the same
hardware domain as physical bridge ports as ARP packets that cannot be
suppressed by the bridge will not be able to egress the VXLAN bridge ports
due to hardware domain filtering. This is solved by trapping ARP packets
when they enter the device and not marking them as being forwarded in
hardware.
Patch set overview:
Patch #1 sets hardware to trap ARP packets at layer 2
Patches #2-#4 are preparations for setting hardwarwe domain of VXLAN
Patch #5 sets hardware domain of VXLAN
Patch #6 extends VXLAN flood test to verify that this set solves the
packets duplication
====================
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
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Apr 23, 2025
The commit '245618f8e45f ("block: protect wbt_lat_usec using q->
elevator_lock")' introduced q->elevator_lock to protect updates
to blk-wbt parameters when writing to the sysfs attribute wbt_
lat_usec and the cgroup attribute io.cost.qos. However, both
these attributes also acquire q->rq_qos_mutex, leading to the
following lockdep warning:
======================================================
WARNING: possible circular locking dependency detected
6.14.0-rc5+ torvalds#138 Not tainted
------------------------------------------------------
bash/5902 is trying to acquire lock:
c000000085d495a0 (&q->rq_qos_mutex){+.+.}-{4:4}, at: wbt_init+0x164/0x238
but task is already holding lock:
c000000085d498c8 (&q->elevator_lock){+.+.}-{4:4}, at: queue_wb_lat_store+0xb0/0x20c
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&q->elevator_lock){+.+.}-{4:4}:
__mutex_lock+0xf0/0xa58
ioc_qos_write+0x16c/0x85c
cgroup_file_write+0xc4/0x32c
kernfs_fop_write_iter+0x1b8/0x29c
vfs_write+0x410/0x584
ksys_write+0x84/0x140
system_call_exception+0x134/0x360
system_call_vectored_common+0x15c/0x2ec
-> #0 (&q->rq_qos_mutex){+.+.}-{4:4}:
__lock_acquire+0x1b6c/0x2ae0
lock_acquire+0x140/0x430
__mutex_lock+0xf0/0xa58
wbt_init+0x164/0x238
queue_wb_lat_store+0x1dc/0x20c
queue_attr_store+0x12c/0x164
sysfs_kf_write+0x6c/0xb0
kernfs_fop_write_iter+0x1b8/0x29c
vfs_write+0x410/0x584
ksys_write+0x84/0x140
system_call_exception+0x134/0x360
system_call_vectored_common+0x15c/0x2ec
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&q->elevator_lock);
lock(&q->rq_qos_mutex);
lock(&q->elevator_lock);
lock(&q->rq_qos_mutex);
*** DEADLOCK ***
6 locks held by bash/5902:
#0: c000000051122400 (sb_writers#3){.+.+}-{0:0}, at: ksys_write+0x84/0x140
#1: c00000007383f088 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x174/0x29c
#2: c000000008550428 (kn->active#182){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x180/0x29c
#3: c000000085d493a8 (&q->q_usage_counter(io)#5){++++}-{0:0}, at: blk_mq_freeze_queue_nomemsave+0x28/0x40
#4: c000000085d493e0 (&q->q_usage_counter(queue)#5){++++}-{0:0}, at: blk_mq_freeze_queue_nomemsave+0x28/0x40
#5: c000000085d498c8 (&q->elevator_lock){+.+.}-{4:4}, at: queue_wb_lat_store+0xb0/0x20c
stack backtrace:
CPU: 17 UID: 0 PID: 5902 Comm: bash Kdump: loaded Not tainted 6.14.0-rc5+ torvalds#138
Hardware name: IBM,9043-MRX POWER10 (architected) 0x800200 0xf000006 of:IBM,FW1060.00 (NM1060_028) hv:phyp pSeries
Call Trace:
[c0000000721ef590] [c00000000118f8a8] dump_stack_lvl+0x108/0x18c (unreliable)
[c0000000721ef5c0] [c00000000022563c] print_circular_bug+0x448/0x604
[c0000000721ef670] [c000000000225a44] check_noncircular+0x24c/0x26c
[c0000000721ef740] [c00000000022bf28] __lock_acquire+0x1b6c/0x2ae0
[c0000000721ef870] [c000000000229240] lock_acquire+0x140/0x430
[c0000000721ef970] [c0000000011cfbec] __mutex_lock+0xf0/0xa58
[c0000000721efaa0] [c00000000096c46c] wbt_init+0x164/0x238
[c0000000721efaf0] [c0000000008f8cd8] queue_wb_lat_store+0x1dc/0x20c
[c0000000721efb50] [c0000000008f8fa0] queue_attr_store+0x12c/0x164
[c0000000721efc60] [c0000000007c11cc] sysfs_kf_write+0x6c/0xb0
[c0000000721efca0] [c0000000007bfa4c] kernfs_fop_write_iter+0x1b8/0x29c
[c0000000721efcf0] [c0000000006a281c] vfs_write+0x410/0x584
[c0000000721efdc0] [c0000000006a2cc8] ksys_write+0x84/0x140
[c0000000721efe10] [c000000000031b64] system_call_exception+0x134/0x360
[c0000000721efe50] [c00000000000cedc] system_call_vectored_common+0x15c/0x2ec
>From the above log it's apparent that method which writes to sysfs attr
wbt_lat_usec acquires q->elevator_lock first, and then acquires q->rq_
qos_mutex. However the another method which writes to io.cost.qos,
acquires q->rq_qos_mutex first, and then acquires q->rq_qos_mutex. So
this could potentially cause the deadlock.
A closer look at ioc_qos_write shows that correcting the lock order is
non-trivial because q->rq_qos_mutex is acquired in blkg_conf_open_bdev
and released in blkg_conf_exit. The function blkg_conf_open_bdev is
responsible for parsing user input and finding the corresponding block
device (bdev) from the user provided major:minor number.
Since we do not know the bdev until blkg_conf_open_bdev completes, we
cannot simply move q->elevator_lock acquisition before blkg_conf_open_
bdev. So to address this, we intoduce new helpers blkg_conf_open_bdev_
frozen and blkg_conf_exit_frozen which are just wrappers around blkg_
conf_open_bdev and blkg_conf_exit respectively. The helper blkg_conf_
open_bdev_frozen is similar to blkg_conf_open_bdev, but additionally
freezes the queue, acquires q->elevator_lock and ensures the correct
locking order is followed between q->elevator_lock and q->rq_qos_mutex.
Similarly another helper blkg_conf_exit_frozen in addition to unfreezing
the queue ensures that we release the locks in correct order.
By using these helpers, now we maintain the same locking order in all
code paths where we update blk-wbt parameters.
Fixes: 245618f ("block: protect wbt_lat_usec using q->elevator_lock")
Reported-by: kernel test robot <[email protected]>
Closes: https://lore.kernel.org/oe-lkp/[email protected]
Signed-off-by: Nilay Shroff <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>
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Apr 23, 2025
We have recently seen report of lockdep circular lock dependency warnings on platforms like Skylake and Kabylake: ====================================================== WARNING: possible circular locking dependency detected 6.14.0-rc6-CI_DRM_16276-gca2c04fe76e8+ #1 Not tainted ------------------------------------------------------ swapper/0/1 is trying to acquire lock: ffffffff8360ee48 (iommu_probe_device_lock){+.+.}-{3:3}, at: iommu_probe_device+0x1d/0x70 but task is already holding lock: ffff888102c7efa8 (&device->physical_node_lock){+.+.}-{3:3}, at: intel_iommu_init+0xe75/0x11f0 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #6 (&device->physical_node_lock){+.+.}-{3:3}: __mutex_lock+0xb4/0xe40 mutex_lock_nested+0x1b/0x30 intel_iommu_init+0xe75/0x11f0 pci_iommu_init+0x13/0x70 do_one_initcall+0x62/0x3f0 kernel_init_freeable+0x3da/0x6a0 kernel_init+0x1b/0x200 ret_from_fork+0x44/0x70 ret_from_fork_asm+0x1a/0x30 -> #5 (dmar_global_lock){++++}-{3:3}: down_read+0x43/0x1d0 enable_drhd_fault_handling+0x21/0x110 cpuhp_invoke_callback+0x4c6/0x870 cpuhp_issue_call+0xbf/0x1f0 __cpuhp_setup_state_cpuslocked+0x111/0x320 __cpuhp_setup_state+0xb0/0x220 irq_remap_enable_fault_handling+0x3f/0xa0 apic_intr_mode_init+0x5c/0x110 x86_late_time_init+0x24/0x40 start_kernel+0x895/0xbd0 x86_64_start_reservations+0x18/0x30 x86_64_start_kernel+0xbf/0x110 common_startup_64+0x13e/0x141 -> #4 (cpuhp_state_mutex){+.+.}-{3:3}: __mutex_lock+0xb4/0xe40 mutex_lock_nested+0x1b/0x30 __cpuhp_setup_state_cpuslocked+0x67/0x320 __cpuhp_setup_state+0xb0/0x220 page_alloc_init_cpuhp+0x2d/0x60 mm_core_init+0x18/0x2c0 start_kernel+0x576/0xbd0 x86_64_start_reservations+0x18/0x30 x86_64_start_kernel+0xbf/0x110 common_startup_64+0x13e/0x141 -> #3 (cpu_hotplug_lock){++++}-{0:0}: __cpuhp_state_add_instance+0x4f/0x220 iova_domain_init_rcaches+0x214/0x280 iommu_setup_dma_ops+0x1a4/0x710 iommu_device_register+0x17d/0x260 intel_iommu_init+0xda4/0x11f0 pci_iommu_init+0x13/0x70 do_one_initcall+0x62/0x3f0 kernel_init_freeable+0x3da/0x6a0 kernel_init+0x1b/0x200 ret_from_fork+0x44/0x70 ret_from_fork_asm+0x1a/0x30 -> #2 (&domain->iova_cookie->mutex){+.+.}-{3:3}: __mutex_lock+0xb4/0xe40 mutex_lock_nested+0x1b/0x30 iommu_setup_dma_ops+0x16b/0x710 iommu_device_register+0x17d/0x260 intel_iommu_init+0xda4/0x11f0 pci_iommu_init+0x13/0x70 do_one_initcall+0x62/0x3f0 kernel_init_freeable+0x3da/0x6a0 kernel_init+0x1b/0x200 ret_from_fork+0x44/0x70 ret_from_fork_asm+0x1a/0x30 -> #1 (&group->mutex){+.+.}-{3:3}: __mutex_lock+0xb4/0xe40 mutex_lock_nested+0x1b/0x30 __iommu_probe_device+0x24c/0x4e0 probe_iommu_group+0x2b/0x50 bus_for_each_dev+0x7d/0xe0 iommu_device_register+0xe1/0x260 intel_iommu_init+0xda4/0x11f0 pci_iommu_init+0x13/0x70 do_one_initcall+0x62/0x3f0 kernel_init_freeable+0x3da/0x6a0 kernel_init+0x1b/0x200 ret_from_fork+0x44/0x70 ret_from_fork_asm+0x1a/0x30 -> #0 (iommu_probe_device_lock){+.+.}-{3:3}: __lock_acquire+0x1637/0x2810 lock_acquire+0xc9/0x300 __mutex_lock+0xb4/0xe40 mutex_lock_nested+0x1b/0x30 iommu_probe_device+0x1d/0x70 intel_iommu_init+0xe90/0x11f0 pci_iommu_init+0x13/0x70 do_one_initcall+0x62/0x3f0 kernel_init_freeable+0x3da/0x6a0 kernel_init+0x1b/0x200 ret_from_fork+0x44/0x70 ret_from_fork_asm+0x1a/0x30 other info that might help us debug this: Chain exists of: iommu_probe_device_lock --> dmar_global_lock --> &device->physical_node_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&device->physical_node_lock); lock(dmar_global_lock); lock(&device->physical_node_lock); lock(iommu_probe_device_lock); *** DEADLOCK *** This driver uses a global lock to protect the list of enumerated DMA remapping units. It is necessary due to the driver's support for dynamic addition and removal of remapping units at runtime. Two distinct code paths require iteration over this remapping unit list: - Device registration and probing: the driver iterates the list to register each remapping unit with the upper layer IOMMU framework and subsequently probe the devices managed by that unit. - Global configuration: Upper layer components may also iterate the list to apply configuration changes. The lock acquisition order between these two code paths was reversed. This caused lockdep warnings, indicating a risk of deadlock. Fix this warning by releasing the global lock before invoking upper layer interfaces for device registration. Fixes: b150654 ("iommu/vt-d: Fix suspicious RCU usage") Closes: https://lore.kernel.org/linux-iommu/SJ1PR11MB612953431F94F18C954C4A9CB9D32@SJ1PR11MB6129.namprd11.prod.outlook.com/ Tested-by: Chaitanya Kumar Borah <[email protected]> Cc: [email protected] Signed-off-by: Lu Baolu <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Joerg Roedel <[email protected]>
michalQb
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Jun 16, 2025
This patch enables support for DYNAMIC_FTRACE_WITH_CALL_OPS on RISC-V. This allows each ftrace callsite to provide an ftrace_ops to the common ftrace trampoline, allowing each callsite to invoke distinct tracer functions without the need to fall back to list processing or to allocate custom trampolines for each callsite. This significantly speeds up cases where multiple distinct trace functions are used and callsites are mostly traced by a single tracer. The idea and most of the implementation is taken from the ARM64's implementation of the same feature. The idea is to place a pointer to the ftrace_ops as a literal at a fixed offset from the function entry point, which can be recovered by the common ftrace trampoline. We use -fpatchable-function-entry to reserve 8 bytes above the function entry by emitting 2 4 byte or 4 2 byte nops depending on the presence of CONFIG_RISCV_ISA_C. These 8 bytes are patched at runtime with a pointer to the associated ftrace_ops for that callsite. Functions are aligned to 8 bytes to make sure that the accesses to this literal are atomic. This approach allows for directly invoking ftrace_ops::func even for ftrace_ops which are dynamically-allocated (or part of a module), without going via ftrace_ops_list_func. We've benchamrked this with the ftrace_ops sample module on Spacemit K1 Jupiter: Without this patch: baseline (Linux rivos 6.14.0-09584-g7d06015d936c #3 SMP Sat Mar 29 +-----------------------+-----------------+----------------------------+ | Number of tracers | Total time (ns) | Per-call average time | |-----------------------+-----------------+----------------------------| | Relevant | Irrelevant | 100000 calls | Total (ns) | Overhead (ns) | |----------+------------+-----------------+------------+---------------| | 0 | 0 | 1357958 | 13 | - | | 0 | 1 | 1302375 | 13 | - | | 0 | 2 | 1302375 | 13 | - | | 0 | 10 | 1379084 | 13 | - | | 0 | 100 | 1302458 | 13 | - | | 0 | 200 | 1302333 | 13 | - | |----------+------------+-----------------+------------+---------------| | 1 | 0 | 13677833 | 136 | 123 | | 1 | 1 | 18500916 | 185 | 172 | | 1 | 2 | 2285645 | 228 | 215 | | 1 | 10 | 58824709 | 588 | 575 | | 1 | 100 | 505141584 | 5051 | 5038 | | 1 | 200 | 1580473126 | 15804 | 15791 | |----------+------------+-----------------+------------+---------------| | 1 | 0 | 13561000 | 135 | 122 | | 2 | 0 | 19707292 | 197 | 184 | | 10 | 0 | 67774750 | 677 | 664 | | 100 | 0 | 714123125 | 7141 | 7128 | | 200 | 0 | 1918065668 | 19180 | 19167 | +----------+------------+-----------------+------------+---------------+ Note: per-call overhead is estimated relative to the baseline case with 0 relevant tracers and 0 irrelevant tracers. With this patch: v4-rc4 (Linux rivos 6.14.0-09598-gd75747611c93 #4 SMP Sat Mar 29 +-----------------------+-----------------+----------------------------+ | Number of tracers | Total time (ns) | Per-call average time | |-----------------------+-----------------+----------------------------| | Relevant | Irrelevant | 100000 calls | Total (ns) | Overhead (ns) | |----------+------------+-----------------+------------+---------------| | 0 | 0 | 1459917 | 14 | - | | 0 | 1 | 1408000 | 14 | - | | 0 | 2 | 1383792 | 13 | - | | 0 | 10 | 1430709 | 14 | - | | 0 | 100 | 1383791 | 13 | - | | 0 | 200 | 1383750 | 13 | - | |----------+------------+-----------------+------------+---------------| | 1 | 0 | 5238041 | 52 | 38 | | 1 | 1 | 5228542 | 52 | 38 | | 1 | 2 | 5325917 | 53 | 40 | | 1 | 10 | 5299667 | 52 | 38 | | 1 | 100 | 5245250 | 52 | 39 | | 1 | 200 | 5238459 | 52 | 39 | |----------+------------+-----------------+------------+---------------| | 1 | 0 | 5239083 | 52 | 38 | | 2 | 0 | 19449417 | 194 | 181 | | 10 | 0 | 67718584 | 677 | 663 | | 100 | 0 | 709840708 | 7098 | 7085 | | 200 | 0 | 2203580626 | 22035 | 22022 | +----------+------------+-----------------+------------+---------------+ Note: per-call overhead is estimated relative to the baseline case with 0 relevant tracers and 0 irrelevant tracers. As can be seen from the above: a) Whenever there is a single relevant tracer function associated with a tracee, the overhead of invoking the tracer is constant, and does not scale with the number of tracers which are *not* associated with that tracee. b) The overhead for a single relevant tracer has dropped to ~1/3 of the overhead prior to this series (from 122ns to 38ns). This is largely due to permitting calls to dynamically-allocated ftrace_ops without going through ftrace_ops_list_func. Signed-off-by: Puranjay Mohan <[email protected]> [update kconfig, asm, refactor] Signed-off-by: Andy Chiu <[email protected]> Tested-by: Björn Töpel <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexandre Ghiti <[email protected]> Signed-off-by: Palmer Dabbelt <[email protected]>
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