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2026-08-27net/sched: sch_htb: limit htb_classify inner-class filter hopsJamal Hadi Salim1-2/+5
htb_classify() follows each filter-selected inner class by switching to cl->filter_list, but never bounds the number of hops. A filter on an inner class can point back to itself or to another inner class that points back, creating an infinite loop in the packet classification path with the qdisc lock held and BH disabled — a soft lockup / panic from a single packet. Bound the traversal with a hop counter and drop the packet with a rate-limited warning once the bound is exceeded. The counter is incremented at the point the inner filter chain is picked up, after the TC_ACT_* switch has consumed the classifier verdict, so a terminal TC_ACT_QUEUED/STOLEN/TRAP on the last permitted chain still sets *qerr to __NET_XMIT_STOLEN and the packet is not charged as a drop by this qdisc or its parent. The bound is TC_HTB_MAXDEPTH, taken from HTB's own parameters rather than from the qdisc hierarchy depth limit. Class levels run from 0 to TC_HTB_MAXDEPTH - 1, so a traversal that strictly descends in level can take at most TC_HTB_MAXDEPTH hops. That descent is what a sane configuration does, but it is assumed here rather than enforced: htb_find() resolves a classid against every class in the qdisc, so a filter may equally select a sibling or an ancestor. The normal root -> inner -> leaf path takes a single hop, so the bound does not affect legitimate classification. htb_classify() can now return NULL irrespective of CONFIG_NET_CLS_ACT, whereas previously every NULL return sat inside that ifdef. The NULL handler in htb_enqueue() therefore cannot stay conditional either, so drop the ifdef around it. This matches hfsc_enqueue(), which has always handled a NULL class unconditionally. Without it, a kernel built without actions would dereference a NULL class instead of dropping. Conditions to recreate the bug: - CONFIG_NET_SCHED, CONFIG_NET_SCH_HTB, CONFIG_NET_CLS_U32, CONFIG_LOCKUP_DETECTOR. - Create an HTB qdisc on a device (e.g. lo), add an inner class 1:1 with a leaf child 1:10, install a root u32 filter selecting 1:1, and an inner-class u32 filter on 1:1 also selecting 1:1. - Send one packet (ping). On the unfixed kernel the classify loop spins with the qdisc lock held; with softlockup_panic=1 it panics. - Reachable from unprivileged user via unshare -Urn (CAP_NET_ADMIN). Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: Vega <vega@nebusec.ai> Co-developed-by: Victor Nogueira <victor@mojatatu.com> Signed-off-by: Victor Nogueira <victor@mojatatu.com> Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260826143339.271935-1-victor@mojatatu.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-20net/sched: Handle TC_ACT_REDIRECT from qdisc filter chainsJamal Hadi Salim1-1/+1
When a TC filter attached to a qdisc filter chain returns TC_ACT_REDIRECT (ex: via an eBPF program calling bpf_redirect() or an act_bpf action), the redirect was silently lost i.e no qdisc classify function handled TC_ACT_REDIRECT, so the packet fell through the switch and was enqueued normally instead of being redirected. This has been broken since bpf_redirect() was introduced for TC in commit 27b29f63058d ("bpf: add bpf_redirect() helper"). We got lucky for a long time because bpf_net_context was a per-CPU variable that was always available. commit 401cb7dae813 ("net: Reference bpf_redirect_info via task_struct on PREEMPT_RT.") turned bpf_net_context into a task_struct member that is only set up by explicit callers. Without a caller setting it up, bpf_redirect() itself crashes with a NULL pointer dereference in bpf_net_ctx_get_ri(). However, even with bpf_net_context available, TC_ACT_REDIRECT from qdisc filter chains cannot be honored without adding skb_do_redirect() calls to every qdisc classify function, which would require changes across net/sched/. Isolate it to ebpf core where it belongs. Instead, add a tcf_classify_qdisc() inline helper in pkt_cls.h, as a wrapper around tcf_classify() for use by qdisc classify functions and tcf_qevent_handle(). When the classify verdict is TC_ACT_REDIRECT, the wrapper converts it to TC_ACT_SHOT, dropping the packet rather than letting it continue silently. Dropping is preferred over letting the packet through because the user immediately sees packet loss. Silently passing the packet through would hide the problem and leave the user wondering why their redirect is not working. The clsact fast path, tc_run() continues to call tcf_classify() directly and is unaffected: TC_ACT_REDIRECT is returned as-is and handled by sch_handle_egress/ingress() calling skb_do_redirect() as before. Fixes: 27b29f63058d ("bpf: add bpf_redirect() helper") Fixes: 401cb7dae813 ("net: Reference bpf_redirect_info via task_struct on PREEMPT_RT.") Tested-by: Victor Nogueira <victor@mojatatu.com> Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Link: https://patch.msgid.link/20260706185609.330006-3-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-19net/sched: sch_htb: fix htb_dump_class_stats() vs offload modeEric Dumazet1-10/+12
htb_dump_class_stats() and htb_offload_aggregate_stats() call gnet_stats_basic_sync_init(&cl->bstats) which is wrong on 32bit arches when syncp is cleared. Make sure to acquire qdisc spinlock and use _bstats_set() to ease future lockless dumps. Fixes: 83271586249c ("sch_htb: Stats for offloaded HTB") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Maxim Mikityanskiy <maximmi@mellanox.com> Cc: Tariq Toukan <tariqt@nvidia.com> Link: https://patch.msgid.link/20260518090518.629245-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-15net/sched: sch_htb: annotate data-races (III)Eric Dumazet1-11/+12
htb_dump_class_stats() will soon run locklessly. (no RTNL, not qdisc spinlock). Add READ_ONCE()/WRITE_ONCE() annotations on these fields: - cl->overlimits - cl->drops - cl->tokens - cl->ctokens Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260514095935.3926276-5-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-15net/sched: sch_htb: annotate data-races (II)Eric Dumazet1-8/+13
htb_dump_class_stats() will soon run locklessly. (no RTNL, not qdisc spinlock). Remove cl->xstats and replace it with two fields: - xstats_lends - xstats_borrows Then use READ_ONCE()/WRITE_ONCE() annotations on them, and change htb_dump_class_stats to use a private struct tc_htb_xstats. Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260514095935.3926276-4-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-15net/sched: sch_htb: annotate data-races (I)Eric Dumazet1-4/+4
htb_dump() runs without holding qdisc spinlock. Add missing READ_ONCE()/WRITE_ONCE() annotations around q->overlimits and q->direct_pkts. Fixes: edb09eb17ed8 ("net: sched: do not acquire qdisc spinlock in qdisc/class stats dump") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260514095935.3926276-3-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-15net/sched: sch_htb: do not change sch->flags in htb_dump()Eric Dumazet1-5/+1
htb_dump() runs without holding qdisc spinlock. It is illegal to touch sch->flags with non locked RMW, as concurrent readers might see intermediate wrong values. Set TCQ_F_OFFLOADED in control path (htb_init()) instead. Fixes: d03b195b5aa0 ("sch_htb: Hierarchical QoS hardware offload") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260514095935.3926276-2-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-11net/sched: annotate data-races around sch->qstats.backlogEric Dumazet1-1/+1
Add qstats_backlog_sub() and qstats_backlog_add() helpers and use them instead of open-coding them. These helpers use WRITE_ONCE() to prevent store-tearing. Also use WRITE_ONCE() in fq_reset() and qdisc_reset() when sch->qstats.backlog is cleared. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Toke Høiland-Jørgensen <toke@toke.dk> Link: https://patch.msgid.link/20260510091455.4039245-4-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-11net/sched: add qdisc_qlen_inc() and qdisc_qlen_dec()Eric Dumazet1-2/+2
Helpers to increment or decrement sch->q.qlen, with appropriate WRITE_ONCE() to prevent store tearing. Add other WRITE_ONCE() when sch->q.qlen is changed. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Toke Høiland-Jørgensen <toke@toke.dk> Link: https://patch.msgid.link/20260510091455.4039245-3-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-09net/sched: do not reset queues in graft operationsEric Dumazet1-2/+2
Following typical script is extremely disruptive, because each graft operation calls dev_deactivate() which resets all the queues of the device. QPARAM="limit 100000 flow_limit 1000 buckets 4096" TXQS=64 for ETH in eth1 do tc qd del dev $ETH root 2>/dev/null tc qd add dev $ETH root handle 1: mq for i in `seq 1 $TXQS` do slot=$( printf %x $(( i )) ) tc qd add dev $ETH parent 1:$slot fq $QPARAM done done One can add "ip link set dev $ETH down/up" to reduce the disruption time: QPARAM="limit 100000 flow_limit 1000 buckets 4096" TXQS=64 for ETH in eth1 do ip link set dev $ETH down tc qd del dev $ETH root 2>/dev/null tc qd add dev $ETH root handle 1: mq for i in `seq 1 $TXQS` do slot=$( printf %x $(( i )) ) tc qd add dev $ETH parent 1:$slot fq $QPARAM done ip link set dev $ETH up done Or we can add a @reset_needed flag to dev_deactivate() and dev_deactivate_many(). This flag is set to true at device dismantle or linkwatch_do_dev(), and to false for graft operations. In the future, we might only stop one queue instead of the whole device, ie call dev_deactivate_queue() instead of dev_deactivate(). I think the problem (quadratic behavior) was added in commit 2fb541c862c9 ("net: sch_generic: aviod concurrent reset and enqueue op for lockless qdisc") but this does not look serious enough to deserve risky backports. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Yunsheng Lin <linyunsheng@huawei.com> Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Reviewed-by: Victor Nogueira <victor@mojatatu.com> Link: https://patch.msgid.link/20260307163430.470644-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-22Convert remaining multi-line kmalloc_obj/flex GFP_KERNEL usesKees Cook1-2/+1
Conversion performed via this Coccinelle script: // SPDX-License-Identifier: GPL-2.0-only // Options: --include-headers-for-types --all-includes --include-headers --keep-comments virtual patch @gfp depends on patch && !(file in "tools") && !(file in "samples")@ identifier ALLOC = {kmalloc_obj,kmalloc_objs,kmalloc_flex, kzalloc_obj,kzalloc_objs,kzalloc_flex, kvmalloc_obj,kvmalloc_objs,kvmalloc_flex, kvzalloc_obj,kvzalloc_objs,kvzalloc_flex}; @@ ALLOC(... - , GFP_KERNEL ) $ make coccicheck MODE=patch COCCI=gfp.cocci Build and boot tested x86_64 with Fedora 42's GCC and Clang: Linux version 6.19.0+ (user@host) (gcc (GCC) 15.2.1 20260123 (Red Hat 15.2.1-7), GNU ld version 2.44-12.fc42) #1 SMP PREEMPT_DYNAMIC 1970-01-01 Linux version 6.19.0+ (user@host) (clang version 20.1.8 (Fedora 20.1.8-4.fc42), LLD 20.1.8) #1 SMP PREEMPT_DYNAMIC 1970-01-01 Signed-off-by: Kees Cook <kees@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21Convert 'alloc_obj' family to use the new default GFP_KERNEL argumentLinus Torvalds1-1/+1
This was done entirely with mindless brute force, using git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' | xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/' to convert the new alloc_obj() users that had a simple GFP_KERNEL argument to just drop that argument. Note that due to the extreme simplicity of the scripting, any slightly more complex cases spread over multiple lines would not be triggered: they definitely exist, but this covers the vast bulk of the cases, and the resulting diff is also then easier to check automatically. For the same reason the 'flex' versions will be done as a separate conversion. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21treewide: Replace kmalloc with kmalloc_obj for non-scalar typesKees Cook1-4/+4
This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook <kees@kernel.org>
2025-08-20net/sched: Remove unnecessary WARNING condition for empty child qdisc in ↵William Liu1-1/+1
htb_activate The WARN_ON trigger based on !cl->leaf.q->q.qlen is unnecessary in htb_activate. htb_dequeue_tree already accounts for that scenario. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: William Liu <will@willsroot.io> Reviewed-by: Savino Dicanosa <savy@syst3mfailure.io> Link: https://patch.msgid.link/20250819033632.579854-1-will@willsroot.io Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-17net/sched: Return NULL when htb_lookup_leaf encounters an empty rbtreeWilliam Liu1-1/+3
htb_lookup_leaf has a BUG_ON that can trigger with the following: tc qdisc del dev lo root tc qdisc add dev lo root handle 1: htb default 1 tc class add dev lo parent 1: classid 1:1 htb rate 64bit tc qdisc add dev lo parent 1:1 handle 2: netem tc qdisc add dev lo parent 2:1 handle 3: blackhole ping -I lo -c1 -W0.001 127.0.0.1 The root cause is the following: 1. htb_dequeue calls htb_dequeue_tree which calls the dequeue handler on the selected leaf qdisc 2. netem_dequeue calls enqueue on the child qdisc 3. blackhole_enqueue drops the packet and returns a value that is not just NET_XMIT_SUCCESS 4. Because of this, netem_dequeue calls qdisc_tree_reduce_backlog, and since qlen is now 0, it calls htb_qlen_notify -> htb_deactivate -> htb_deactiviate_prios -> htb_remove_class_from_row -> htb_safe_rb_erase 5. As this is the only class in the selected hprio rbtree, __rb_change_child in __rb_erase_augmented sets the rb_root pointer to NULL 6. Because blackhole_dequeue returns NULL, netem_dequeue returns NULL, which causes htb_dequeue_tree to call htb_lookup_leaf with the same hprio rbtree, and fail the BUG_ON The function graph for this scenario is shown here: 0) | htb_enqueue() { 0) + 13.635 us | netem_enqueue(); 0) 4.719 us | htb_activate_prios(); 0) # 2249.199 us | } 0) | htb_dequeue() { 0) 2.355 us | htb_lookup_leaf(); 0) | netem_dequeue() { 0) + 11.061 us | blackhole_enqueue(); 0) | qdisc_tree_reduce_backlog() { 0) | qdisc_lookup_rcu() { 0) 1.873 us | qdisc_match_from_root(); 0) 6.292 us | } 0) 1.894 us | htb_search(); 0) | htb_qlen_notify() { 0) 2.655 us | htb_deactivate_prios(); 0) 6.933 us | } 0) + 25.227 us | } 0) 1.983 us | blackhole_dequeue(); 0) + 86.553 us | } 0) # 2932.761 us | qdisc_warn_nonwc(); 0) | htb_lookup_leaf() { 0) | BUG_ON(); ------------------------------------------ The full original bug report can be seen here [1]. We can fix this just by returning NULL instead of the BUG_ON, as htb_dequeue_tree returns NULL when htb_lookup_leaf returns NULL. [1] https://lore.kernel.org/netdev/pF5XOOIim0IuEfhI-SOxTgRvNoDwuux7UHKnE_Y5-zVd4wmGvNk2ceHjKb8ORnzw0cGwfmVu42g9dL7XyJLf1NEzaztboTWcm0Ogxuojoeo=@willsroot.io/ Fixes: 512bb43eb542 ("pkt_sched: sch_htb: Optimize WARN_ONs in htb_dequeue_tree() etc.") Signed-off-by: William Liu <will@willsroot.io> Signed-off-by: Savino Dicanosa <savy@syst3mfailure.io> Link: https://patch.msgid.link/20250717022816.221364-1-will@willsroot.io Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-05-05sch_htb: make htb_deactivate() idempotentCong Wang1-9/+6
Alan reported a NULL pointer dereference in htb_next_rb_node() after we made htb_qlen_notify() idempotent. It turns out in the following case it introduced some regression: htb_dequeue_tree(): |-> fq_codel_dequeue() |-> qdisc_tree_reduce_backlog() |-> htb_qlen_notify() |-> htb_deactivate() |-> htb_next_rb_node() |-> htb_deactivate() For htb_next_rb_node(), after calling the 1st htb_deactivate(), the clprio[prio]->ptr could be already set to NULL, which means htb_next_rb_node() is vulnerable here. For htb_deactivate(), although we checked qlen before calling it, in case of qlen==0 after qdisc_tree_reduce_backlog(), we may call it again which triggers the warning inside. To fix the issues here, we need to: 1) Make htb_deactivate() idempotent, that is, simply return if we already call it before. 2) Make htb_next_rb_node() safe against ptr==NULL. Many thanks to Alan for testing and for the reproducer. Fixes: 5ba8b837b522 ("sch_htb: make htb_qlen_notify() idempotent") Reported-by: Alan J. Wylie <alan@wylie.me.uk> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Link: https://patch.msgid.link/20250428232955.1740419-2-xiyou.wangcong@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-08sch_htb: make htb_qlen_notify() idempotentCong Wang1-0/+2
htb_qlen_notify() always deactivates the HTB class and in fact could trigger a warning if it is already deactivated. Therefore, it is not idempotent and not friendly to its callers, like fq_codel_dequeue(). Let's make it idempotent to ease qdisc_tree_reduce_backlog() callers' life. Reported-by: Gerrard Tai <gerrard.tai@starlabs.sg> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20250403211033.166059-2-xiyou.wangcong@gmail.com Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-11-11net: convert to nla_get_*_default()Johannes Berg1-2/+2
Most of the original conversion is from the spatch below, but I edited some and left out other instances that were either buggy after conversion (where default values don't fit into the type) or just looked strange. @@ expression attr, def; expression val; identifier fn =~ "^nla_get_.*"; fresh identifier dfn = fn ## "_default"; @@ ( -if (attr) - val = fn(attr); -else - val = def; +val = dfn(attr, def); | -if (!attr) - val = def; -else - val = fn(attr); +val = dfn(attr, def); | -if (!attr) - return def; -return fn(attr); +return dfn(attr, def); | -attr ? fn(attr) : def +dfn(attr, def) | -!attr ? def : fn(attr) +dfn(attr, def) ) Signed-off-by: Johannes Berg <johannes.berg@intel.com> Reviewed-by: Toke Høiland-Jørgensen <toke@kernel.org> Link: https://patch.msgid.link/20241108114145.0580b8684e7f.I740beeaa2f70ebfc19bfca1045a24d6151992790@changeid Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-04-26net/sched: fix false lockdep warning on qdisc root lockDavide Caratti1-19/+3
Xiumei and Christoph reported the following lockdep splat, complaining of the qdisc root lock being taken twice: ============================================ WARNING: possible recursive locking detected 6.7.0-rc3+ #598 Not tainted -------------------------------------------- swapper/2/0 is trying to acquire lock: ffff888177190110 (&sch->q.lock){+.-.}-{2:2}, at: __dev_queue_xmit+0x1560/0x2e70 but task is already holding lock: ffff88811995a110 (&sch->q.lock){+.-.}-{2:2}, at: __dev_queue_xmit+0x1560/0x2e70 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&sch->q.lock); lock(&sch->q.lock); *** DEADLOCK *** May be due to missing lock nesting notation 5 locks held by swapper/2/0: #0: ffff888135a09d98 ((&in_dev->mr_ifc_timer)){+.-.}-{0:0}, at: call_timer_fn+0x11a/0x510 #1: ffffffffaaee5260 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x2c0/0x1ed0 #2: ffffffffaaee5200 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x209/0x2e70 #3: ffff88811995a110 (&sch->q.lock){+.-.}-{2:2}, at: __dev_queue_xmit+0x1560/0x2e70 #4: ffffffffaaee5200 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x209/0x2e70 stack backtrace: CPU: 2 PID: 0 Comm: swapper/2 Not tainted 6.7.0-rc3+ #598 Hardware name: Red Hat KVM, BIOS 1.13.0-2.module+el8.3.0+7353+9de0a3cc 04/01/2014 Call Trace: <IRQ> dump_stack_lvl+0x4a/0x80 __lock_acquire+0xfdd/0x3150 lock_acquire+0x1ca/0x540 _raw_spin_lock+0x34/0x80 __dev_queue_xmit+0x1560/0x2e70 tcf_mirred_act+0x82e/0x1260 [act_mirred] tcf_action_exec+0x161/0x480 tcf_classify+0x689/0x1170 prio_enqueue+0x316/0x660 [sch_prio] dev_qdisc_enqueue+0x46/0x220 __dev_queue_xmit+0x1615/0x2e70 ip_finish_output2+0x1218/0x1ed0 __ip_finish_output+0x8b3/0x1350 ip_output+0x163/0x4e0 igmp_ifc_timer_expire+0x44b/0x930 call_timer_fn+0x1a2/0x510 run_timer_softirq+0x54d/0x11a0 __do_softirq+0x1b3/0x88f irq_exit_rcu+0x18f/0x1e0 sysvec_apic_timer_interrupt+0x6f/0x90 </IRQ> This happens when TC does a mirred egress redirect from the root qdisc of device A to the root qdisc of device B. As long as these two locks aren't protecting the same qdisc, they can be acquired in chain: add a per-qdisc lockdep key to silence false warnings. This dynamic key should safely replace the static key we have in sch_htb: it was added to allow enqueueing to the device "direct qdisc" while still holding the qdisc root lock. v2: don't use static keys anymore in HTB direct qdiscs (thanks Eric Dumazet) CC: Maxim Mikityanskiy <maxim@isovalent.com> CC: Xiumei Mu <xmu@redhat.com> Reported-by: Christoph Paasch <cpaasch@apple.com> Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/451 Signed-off-by: Davide Caratti <dcaratti@redhat.com> Link: https://lore.kernel.org/r/7dc06d6158f72053cf877a82e2a7a5bd23692faa.1713448007.git.dcaratti@redhat.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-02-02net/sched: Add module aliases for cls_,sch_,act_ modulesMichal Koutný1-0/+1
No functional change intended, aliases will be used in followup commits. Note for backporters: you may need to add aliases also for modules that are already removed in mainline kernel but still in your version. Patches were generated with the help of Coccinelle scripts like: cat >scripts/coccinelle/misc/tcf_alias.cocci <<EOD virtual patch virtual report @ haskernel @ @@ @ tcf_has_kind depends on report && haskernel @ identifier ops; constant K; @@ static struct tcf_proto_ops ops = { .kind = K, ... }; +char module_alias = K; EOD /usr/bin/spatch -D report --cocci-file scripts/coccinelle/misc/tcf_alias.cocci \ --dir . \ -I ./arch/x86/include -I ./arch/x86/include/generated -I ./include \ -I ./arch/x86/include/uapi -I ./arch/x86/include/generated/uapi \ -I ./include/uapi -I ./include/generated/uapi \ --include ./include/linux/compiler-version.h --include ./include/linux/kconfig.h \ --jobs 8 --chunksize 1 2>/dev/null | \ sed 's/char module_alias = "\([^"]*\)";/MODULE_ALIAS_NET_CLS("\1");/' And analogously for: static struct tc_action_ops ops = { .kind = K, static struct Qdisc_ops ops = { .id = K, (Someone familiar would be able to fit those into one .cocci file without sed post processing.) Signed-off-by: Michal Koutný <mkoutny@suse.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Link: https://lore.kernel.org/r/20240201130943.19536-3-mkoutny@suse.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-11-01net: sched: Fill in missing MODULE_DESCRIPTION for qdiscsVictor Nogueira1-0/+1
W=1 builds now warn if module is built without a MODULE_DESCRIPTION(). Fill in missing MODULE_DESCRIPTIONs for TC qdiscs. Signed-off-by: Victor Nogueira <victor@mojatatu.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Reviewed-by: Vinicius Costa Gomes <vinicius.gomes@intel.com> Link: https://lore.kernel.org/r/20231027155045.46291-4-victor@mojatatu.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-08-01net/sched: sch_htb: warn about class in use while deletingPedro Tammela1-1/+3
Add extack to warn that delete was rejected because the class is still in use Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Pedro Tammela <pctammela@mojatatu.com> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-08-01net/sched: wrap open coded Qdics class filter counterPedro Tammela1-5/+3
The 'filter_cnt' counter is used to control a Qdisc class lifetime. Each filter referecing this class by its id will eventually increment/decrement this counter in their respective 'add/update/delete' routines. As these operations are always serialized under rtnl lock, we don't need an atomic type like 'refcount_t'. It also means that we lose the overflow/underflow checks already present in refcount_t, which are valuable to hunt down bugs where the unsigned counter wraps around as it aids automated tools like syzkaller to scream in such situations. Wrap the open coded increment/decrement into helper functions and add overflow checks to the operations. Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Pedro Tammela <pctammela@mojatatu.com> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-07-21sch_htb: Allow HTB quantum parameter in offload modeNaveen Mamindlapalli1-4/+3
The current implementation of HTB offload returns the EINVAL error for quantum parameter. This patch removes the error returning checks for 'quantum' parameter and populates its value to tc_htb_qopt_offload structure such that driver can use the same. Add quantum parameter check in mlx5 driver, as mlx5 devices are not capable of supporting the quantum parameter when htb offload is used. Report error if quantum parameter is set to a non-default value. Signed-off-by: Naveen Mamindlapalli <naveenm@marvell.com> Signed-off-by: Hariprasad Kelam <hkelam@marvell.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-15sch_htb: Allow HTB priority parameter in offload modeNaveen Mamindlapalli1-4/+3
The current implementation of HTB offload returns the EINVAL error for unsupported parameters like prio and quantum. This patch removes the error returning checks for 'prio' parameter and populates its value to tc_htb_qopt_offload structure such that driver can use the same. Add prio parameter check in mlx5 driver, as mlx5 devices are not capable of supporting the prio parameter when htb offload is used. Report error if prio parameter is set to a non-default value. Signed-off-by: Naveen Mamindlapalli <naveenm@marvell.com> Co-developed-by: Rahul Rameshbabu <rrameshbabu@nvidia.com> Signed-off-by: Rahul Rameshbabu <rrameshbabu@nvidia.com> Signed-off-by: Hariprasad Kelam <hkelam@marvell.com> Signed-off-by: Sunil Kovvuri Goutham <sgoutham@marvell.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-04-23net/sched: sch_htb: use extack on errors messagesPedro Tammela1-8/+9
Some error messages are still being printed to dmesg. Since extack is available, provide error messages there. Reviewed-by: Simon Horman <simon.horman@corigine.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Pedro Tammela <pctammela@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-02-07net: sched: sch: Fix off by one in htb_activate_prios()Dan Carpenter1-1/+1
The > needs be >= to prevent an out of bounds access. Fixes: de5ca4c3852f ("net: sched: sch: Bounds check priority") Signed-off-by: Dan Carpenter <error27@gmail.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/Y+D+KN18FQI2DKLq@kili Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-01-31net: sched: sch: Bounds check priorityKees Cook1-1/+4
Nothing was explicitly bounds checking the priority index used to access clpriop[]. WARN and bail out early if it's pathological. Seen with GCC 13: ../net/sched/sch_htb.c: In function 'htb_activate_prios': ../net/sched/sch_htb.c:437:44: warning: array subscript [0, 31] is outside array bounds of 'struct htb_prio[8]' [-Warray-bounds=] 437 | if (p->inner.clprio[prio].feed.rb_node) | ~~~~~~~~~~~~~~~^~~~~~ ../net/sched/sch_htb.c:131:41: note: while referencing 'clprio' 131 | struct htb_prio clprio[TC_HTB_NUMPRIO]; | ^~~~~~ Cc: Jamal Hadi Salim <jhs@mojatatu.com> Cc: Cong Wang <xiyou.wangcong@gmail.com> Cc: Jiri Pirko <jiri@resnulli.us> Cc: "David S. Miller" <davem@davemloft.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Paolo Abeni <pabeni@redhat.com> Cc: netdev@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Simon Horman <simon.horman@corigine.com> Reviewed-by: Cong Wang <cong.wang@bytedance.com> Link: https://lore.kernel.org/r/20230127224036.never.561-kees@kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-01-13sch_htb: Avoid grafting on htb_destroy_class_offload when destroying htbRahul Rameshbabu1-11/+16
Peek at old qdisc and graft only when deleting a leaf class in the htb, rather than when deleting the htb itself. Do not peek at the qdisc of the netdev queue when destroying the htb. The caller may already have grafted a new qdisc that is not part of the htb structure being destroyed. This fix resolves two use cases. 1. Using tc to destroy the htb. - Netdev was being prematurely activated before the htb was fully destroyed. 2. Using tc to replace the htb with another qdisc (which also leads to the htb being destroyed). - Premature netdev activation like previous case. Newly grafted qdisc was also getting accidentally overwritten when destroying the htb. Fixes: d03b195b5aa0 ("sch_htb: Hierarchical QoS hardware offload") Signed-off-by: Rahul Rameshbabu <rrameshbabu@nvidia.com> Reviewed-by: Saeed Mahameed <saeedm@nvidia.com> Reviewed-by: Maxim Mikityanskiy <maxtram95@gmail.com> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Link: https://lore.kernel.org/r/20230113005528.302625-1-rrameshbabu@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-01-02net: sched: htb: fix htb_classify() kernel-docRandy Dunlap1-2/+6
Fix W=1 kernel-doc warning: net/sched/sch_htb.c:214: warning: expecting prototype for htb_classify(). Prototype was for HTB_DIRECT() instead by moving the HTB_DIRECT() macro above the function. Add kernel-doc notation for function parameters as well. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Jamal Hadi Salim <jhs@mojatatu.com> Cc: Cong Wang <xiyou.wangcong@gmail.com> Cc: Jiri Pirko <jiri@resnulli.us> Cc: "David S. Miller" <davem@davemloft.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-09-22net/sched: use tc_qdisc_stats_dump() in qdiscZhengchao Shao1-8/+1
use tc_qdisc_stats_dump() in qdisc. Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com> Reviewed-by: Victor Nogueira <victor@mojatatu.com> Tested-by: Victor Nogueira <victor@mojatatu.com> Acked-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-09-03net: sched: htb: remove redundant resource cleanup in htb_init()Zhengchao Shao1-27/+9
If htb_init() fails, qdisc_create() invokes htb_destroy() to clear resources. Therefore, remove redundant resource cleanup in htb_init(). Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-08-26net: sched: remove unnecessary init of qdisc skb headZhengchao Shao1-2/+0
The memory allocated by using kzallloc_node and kcalloc has been cleared. Therefore, the structure members of the new qdisc are 0. So there's no need to explicitly assign a value of 0. Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-08-25net: sched: delete duplicate cleanup of backlog and qlenZhengchao Shao1-2/+0
qdisc_reset() is clearing qdisc->q.qlen and qdisc->qstats.backlog _after_ calling qdisc->ops->reset. There is no need to clear them again in the specific reset function. Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com> Link: https://lore.kernel.org/r/20220824005231.345727-1-shaozhengchao@huawei.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-01-25sch_htb: Fail on unsupported parameters when offload is requestedMaxim Mikityanskiy1-0/+20
The current implementation of HTB offload doesn't support some parameters. Instead of ignoring them, actively return the EINVAL error when they are set to non-defaults. As this patch goes to stable, the driver API is not changed here. If future drivers support more offload parameters, the checks can be moved to the driver side. Note that the buffer and cbuffer parameters are also not supported, but the tc userspace tool assigns some default values derived from rate and ceil, and identifying these defaults in sch_htb would be unreliable, so they are still ignored. Fixes: d03b195b5aa0 ("sch_htb: Hierarchical QoS hardware offload") Reported-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com> Reviewed-by: Tariq Toukan <tariqt@nvidia.com> Link: https://lore.kernel.org/r/20220125100654.424570-1-maximmi@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-10-28sch_htb: Add extack messages for EOPNOTSUPP errorsMaxim Mikityanskiy1-2/+6
In order to make the "Operation not supported" message clearer to the user, add extack messages explaining why exactly adding offloaded HTB could be not supported in each case. Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com> Reviewed-by: Tariq Toukan <tariqt@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-18net: sched: Remove Qdisc::running sequence counterAhmed S. Darwish1-4/+3
The Qdisc::running sequence counter has two uses: 1. Reliably reading qdisc's tc statistics while the qdisc is running (a seqcount read/retry loop at gnet_stats_add_basic()). 2. As a flag, indicating whether the qdisc in question is running (without any retry loops). For the first usage, the Qdisc::running sequence counter write section, qdisc_run_begin() => qdisc_run_end(), covers a much wider area than what is actually needed: the raw qdisc's bstats update. A u64_stats sync point was thus introduced (in previous commits) inside the bstats structure itself. A local u64_stats write section is then started and stopped for the bstats updates. Use that u64_stats sync point mechanism for the bstats read/retry loop at gnet_stats_add_basic(). For the second qdisc->running usage, a __QDISC_STATE_RUNNING bit flag, accessed with atomic bitops, is sufficient. Using a bit flag instead of a sequence counter at qdisc_run_begin/end() and qdisc_is_running() leads to the SMP barriers implicitly added through raw_read_seqcount() and write_seqcount_begin/end() getting removed. All call sites have been surveyed though, and no required ordering was identified. Now that the qdisc->running sequence counter is no longer used, remove it. Note, using u64_stats implies no sequence counter protection for 64-bit architectures. This can lead to the qdisc tc statistics "packets" vs. "bytes" values getting out of sync on rare occasions. The individual values will still be valid. Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-18net: sched: Merge Qdisc::bstats and Qdisc::cpu_bstats data typesAhmed S. Darwish1-16/+16
The only factor differentiating per-CPU bstats data type (struct gnet_stats_basic_cpu) from the packed non-per-CPU one (struct gnet_stats_basic_packed) was a u64_stats sync point inside the former. The two data types are now equivalent: earlier commits added a u64_stats sync point to the latter. Combine both data types into "struct gnet_stats_basic_sync". This eliminates redundancy and simplifies the bstats read/write APIs. Use u64_stats_t for bstats "packets" and "bytes" data types. On 64-bit architectures, u64_stats sync points do not use sequence counter protection. Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-18net: sched: Use _bstats_update/set() instead of raw writesAhmed S. Darwish1-10/+15
The Qdisc::running sequence counter, used to protect Qdisc::bstats reads from parallel writes, is in the process of being removed. Qdisc::bstats read/writes will synchronize using an internal u64_stats sync point instead. Modify all bstats writes to use _bstats_update(). This ensures that the internal u64_stats sync point is always acquired and released as appropriate. Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-18net: sched: Protect Qdisc::bstats with u64_statsAhmed S. Darwish1-2/+5
The not-per-CPU variant of qdisc tc (traffic control) statistics, Qdisc::gnet_stats_basic_packed bstats, is protected with Qdisc::running sequence counter. This sequence counter is used for reliably protecting bstats reads from parallel writes. Meanwhile, the seqcount's write section covers a much wider area than bstats update: qdisc_run_begin() => qdisc_run_end(). That read/write section asymmetry can lead to needless retries of the read section. To prepare for removing the Qdisc::running sequence counter altogether, introduce a u64_stats sync point inside bstats instead. Modify _bstats_update() to start/end the bstats u64_stats write section. For bisectability, and finer commits granularity, the bstats read section is still protected with a Qdisc::running read/retry loop and qdisc_run_begin/end() still starts/ends that seqcount write section. Once all call sites are modified to use _bstats_update(), the Qdisc::running seqcount will be removed and bstats read/retry loop will be modified to utilize the internal u64_stats sync point. Note, using u64_stats implies no sequence counter protection for 64-bit architectures. This can lead to the statistics "packets" vs. "bytes" values getting out of sync on rare occasions. The individual values will still be valid. [bigeasy: Minor commit message edits, init all gnet_stats_basic_packed.] Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-30sch_htb: Fix inconsistency when leaf qdisc creation failsMaxim Mikityanskiy1-35/+62
In HTB offload mode, qdiscs of leaf classes are grafted to netdev queues. sch_htb expects the dev_queue field of these qdiscs to point to the corresponding queues. However, qdisc creation may fail, and in that case noop_qdisc is used instead. Its dev_queue doesn't point to the right queue, so sch_htb can lose track of used netdev queues, which will cause internal inconsistencies. This commit fixes this bug by keeping track of the netdev queue inside struct htb_class. All reads of cl->leaf.q->dev_queue are replaced by the new field, the two values are synced on writes, and WARNs are added to assert equality of the two values. The driver API has changed: when TC_HTB_LEAF_DEL needs to move a queue, the driver used to pass the old and new queue IDs to sch_htb. Now that there is a new field (offload_queue) in struct htb_class that needs to be updated on this operation, the driver will pass the old class ID to sch_htb instead (it already knows the new class ID). Fixes: d03b195b5aa0 ("sch_htb: Hierarchical QoS hardware offload") Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com> Reviewed-by: Tariq Toukan <tariqt@nvidia.com> Link: https://lore.kernel.org/r/20210826115425.1744053-1-maximmi@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-07-29net/sched: store the last executed chain also for clsact egressDavide Caratti1-1/+1
currently, only 'ingress' and 'clsact ingress' qdiscs store the tc 'chain id' in the skb extension. However, userspace programs (like ovs) are able to setup egress rules, and datapath gets confused in case it doesn't find the 'chain id' for a packet that's "recirculated" by tc. Change tcf_classify() to have the same semantic as tcf_classify_ingress() so that a single function can be called in ingress / egress, using the tc ingress / egress block respectively. Suggested-by: Alaa Hleilel <alaa@nvidia.com> Signed-off-by: Davide Caratti <dcaratti@redhat.com> Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-07Merge ra.kernel.org:/pub/scm/linux/kernel/git/netdev/netDavid S. Miller1-4/+4
Bug fixes overlapping feature additions and refactoring, mostly. Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-07sch_htb: fix doc warning in htb_lookup_leaf()Yu Kuai1-0/+2
Add description for parameters of htb_lookup_leaf() to fix gcc W=1 warnings: net/sched/sch_htb.c:773: warning: Function parameter or member 'hprio' not described in 'htb_lookup_leaf' net/sched/sch_htb.c:773: warning: Function parameter or member 'prio' not described in 'htb_lookup_leaf' Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-07sch_htb: fix doc warning in htb_do_events()Yu Kuai1-0/+3
Add description for parameters of htb_do_events() to fix gcc W=1 warnings: net/sched/sch_htb.c:708: warning: Function parameter or member 'q' not described in 'htb_do_events' net/sched/sch_htb.c:708: warning: Function parameter or member 'level' not described in 'htb_do_events' net/sched/sch_htb.c:708: warning: Function parameter or member 'start' not described in 'htb_do_events' Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-07sch_htb: fix doc warning in htb_charge_class()Yu Kuai1-0/+4
Add description for parameters of htb_charge_class() to fix gcc W=1 warnings: net/sched/sch_htb.c:663: warning: Function parameter or member 'q' not described in 'htb_charge_class' net/sched/sch_htb.c:663: warning: Function parameter or member 'cl' not described in 'htb_charge_class' net/sched/sch_htb.c:663: warning: Function parameter or member 'level' not described in 'htb_charge_class' net/sched/sch_htb.c:663: warning: Function parameter or member 'skb' not described in 'htb_charge_class' Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-07sch_htb: fix doc warning in htb_deactivate()Yu Kuai1-0/+2
Add description for parameters of htb_deactivate() to fix gcc W=1 warnings: net/sched/sch_htb.c:578: warning: Function parameter or member 'q' not described in 'htb_deactivate' net/sched/sch_htb.c:578: warning: Function parameter or member 'cl' not described in 'htb_deactivate' Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-07sch_htb: fix doc warning in htb_activate()Yu Kuai1-0/+2
Add description for parameters of htb_activate() to fix gcc W=1 warnings: net/sched/sch_htb.c:562: warning: Function parameter or member 'q' not described in 'htb_activate' net/sched/sch_htb.c:562: warning: Function parameter or member 'cl' not described in 'htb_activate' Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-07sch_htb: fix doc warning in htb_change_class_mode()Yu Kuai1-0/+3
Add description for parameters of htb_change_class_mode() to fix gcc W=1 warnings: net/sched/sch_htb.c:533: warning: Function parameter or member 'q' not described in 'htb_change_class_mode' net/sched/sch_htb.c:533: warning: Function parameter or member 'cl' not described in 'htb_change_class_mode' net/sched/sch_htb.c:533: warning: Function parameter or member 'diff' not described in 'htb_change_class_mode' Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-07sch_htb: fix doc warning in htb_class_mode()Yu Kuai1-0/+2
Add description for parameters of htb_class_mode() to fix gcc W=1 warnings: net/sched/sch_htb.c:507: warning: Function parameter or member 'cl' not described in 'htb_class_mode' net/sched/sch_htb.c:507: warning: Function parameter or member 'diff' not described in 'htb_class_mode' Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>