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Date:   Tue, 22 Nov 2022 11:12:04 +0800
From:   Tonghao Zhang <xiangxia.m.yue@...il.com>
To:     Hou Tao <houtao1@...wei.com>
Cc:     netdev@...r.kernel.org, Alexei Starovoitov <ast@...nel.org>,
        Daniel Borkmann <daniel@...earbox.net>,
        Andrii Nakryiko <andrii@...nel.org>,
        Martin KaFai Lau <martin.lau@...ux.dev>,
        Song Liu <song@...nel.org>, Yonghong Song <yhs@...com>,
        John Fastabend <john.fastabend@...il.com>,
        KP Singh <kpsingh@...nel.org>,
        Stanislav Fomichev <sdf@...gle.com>,
        Hao Luo <haoluo@...gle.com>, Jiri Olsa <jolsa@...nel.org>,
        bpf <bpf@...r.kernel.org>
Subject: Re: [net-next] bpf: avoid hashtab deadlock with try_lock

.

On Tue, Nov 22, 2022 at 9:16 AM Hou Tao <houtao1@...wei.com> wrote:
>
> Hi,
>
> On 11/21/2022 6:05 PM, xiangxia.m.yue@...il.com wrote:
> > From: Tonghao Zhang <xiangxia.m.yue@...il.com>
> >
> > The commit 20b6cc34ea74 ("bpf: Avoid hashtab deadlock with map_locked"),
> > try to fix deadlock, but in some case, the deadlock occurs:
> >
> > * CPUn in task context with K1, and taking lock.
> > * CPUn interrupted by NMI context, with K2.
> > * They are using the same bucket, but different map_locked.
> It is possible when n_buckets is less than HASHTAB_MAP_LOCK_COUNT (e.g.,
> n_bucket=4). If using hash & min(HASHTAB_MAP_LOCK_MASK, n_bucket - 1) as the
> index of map_locked, I think the deadlock will be gone.
Yes, but for saving memory, HASHTAB_MAP_LOCK_MASK should not be too
large(now this value is 8-1).
if user define n_bucket ,e.g 8192, the part of bucket only are
selected via hash & min(HASHTAB_MAP_LOCK_MASK, n_bucket - 1).
> >           | Task
> >           |
> >       +---v----+
> >       |  CPUn  |
> >       +---^----+
> >
> >           | NMI
> >
> > Anyway, the lockdep still warn:
> > [   36.092222] ================================
> > [   36.092230] WARNING: inconsistent lock state
> > [   36.092234] 6.1.0-rc5+ #81 Tainted: G            E
> > [   36.092236] --------------------------------
> > [   36.092237] inconsistent {INITIAL USE} -> {IN-NMI} usage.
> > [   36.092238] perf/1515 [HC1[1]:SC0[0]:HE0:SE1] takes:
> > [   36.092242] ffff888341acd1a0 (&htab->lockdep_key){....}-{2:2}, at: htab_lock_bucket+0x4d/0x58
> > [   36.092253] {INITIAL USE} state was registered at:
> > [   36.092255]   mark_usage+0x1d/0x11d
> > [   36.092262]   __lock_acquire+0x3c9/0x6ed
> > [   36.092266]   lock_acquire+0x23d/0x29a
> > [   36.092270]   _raw_spin_lock_irqsave+0x43/0x7f
> > [   36.092274]   htab_lock_bucket+0x4d/0x58
> > [   36.092276]   htab_map_delete_elem+0x82/0xfb
> > [   36.092278]   map_delete_elem+0x156/0x1ac
> > [   36.092282]   __sys_bpf+0x138/0xb71
> > [   36.092285]   __do_sys_bpf+0xd/0x15
> > [   36.092288]   do_syscall_64+0x6d/0x84
> > [   36.092291]   entry_SYSCALL_64_after_hwframe+0x63/0xcd
> > [   36.092295] irq event stamp: 120346
> > [   36.092296] hardirqs last  enabled at (120345): [<ffffffff8180b97f>] _raw_spin_unlock_irq+0x24/0x39
> > [   36.092299] hardirqs last disabled at (120346): [<ffffffff81169e85>] generic_exec_single+0x40/0xb9
> > [   36.092303] softirqs last  enabled at (120268): [<ffffffff81c00347>] __do_softirq+0x347/0x387
> > [   36.092307] softirqs last disabled at (120133): [<ffffffff810ba4f0>] __irq_exit_rcu+0x67/0xc6
> > [   36.092311]
> > [   36.092311] other info that might help us debug this:
> > [   36.092312]  Possible unsafe locking scenario:
> > [   36.092312]
> > [   36.092313]        CPU0
> > [   36.092313]        ----
> > [   36.092314]   lock(&htab->lockdep_key);
> > [   36.092315]   <Interrupt>
> > [   36.092316]     lock(&htab->lockdep_key);
> > [   36.092318]
> > [   36.092318]  *** DEADLOCK ***
> > [   36.092318]
> > [   36.092318] 3 locks held by perf/1515:
> > [   36.092320]  #0: ffff8881b9805cc0 (&cpuctx_mutex){+.+.}-{4:4}, at: perf_event_ctx_lock_nested+0x8e/0xba
> > [   36.092327]  #1: ffff8881075ecc20 (&event->child_mutex){+.+.}-{4:4}, at: perf_event_for_each_child+0x35/0x76
> > [   36.092332]  #2: ffff8881b9805c20 (&cpuctx_lock){-.-.}-{2:2}, at: perf_ctx_lock+0x12/0x27
> > [   36.092339]
> > [   36.092339] stack backtrace:
> > [   36.092341] CPU: 0 PID: 1515 Comm: perf Tainted: G            E      6.1.0-rc5+ #81
> > [   36.092344] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
> > [   36.092349] Call Trace:
> > [   36.092351]  <NMI>
> > [   36.092354]  dump_stack_lvl+0x57/0x81
> > [   36.092359]  lock_acquire+0x1f4/0x29a
> > [   36.092363]  ? handle_pmi_common+0x13f/0x1f0
> > [   36.092366]  ? htab_lock_bucket+0x4d/0x58
> > [   36.092371]  _raw_spin_lock_irqsave+0x43/0x7f
> > [   36.092374]  ? htab_lock_bucket+0x4d/0x58
> > [   36.092377]  htab_lock_bucket+0x4d/0x58
> > [   36.092379]  htab_map_update_elem+0x11e/0x220
> > [   36.092386]  bpf_prog_f3a535ca81a8128a_bpf_prog2+0x3e/0x42
> > [   36.092392]  trace_call_bpf+0x177/0x215
> > [   36.092398]  perf_trace_run_bpf_submit+0x52/0xaa
> > [   36.092403]  ? x86_pmu_stop+0x97/0x97
> > [   36.092407]  perf_trace_nmi_handler+0xb7/0xe0
> > [   36.092415]  nmi_handle+0x116/0x254
> > [   36.092418]  ? x86_pmu_stop+0x97/0x97
> > [   36.092423]  default_do_nmi+0x3d/0xf6
> > [   36.092428]  exc_nmi+0xa1/0x109
> > [   36.092432]  end_repeat_nmi+0x16/0x67
> > [   36.092436] RIP: 0010:wrmsrl+0xd/0x1b
> > [   36.092441] Code: 04 01 00 00 c6 84 07 48 01 00 00 01 5b e9 46 15 80 00 5b c3 cc cc cc cc c3 cc cc cc cc 48 89 f2 89 f9 89 f0 48 c1 ea 20 0f 30 <66> 90 c3 cc cc cc cc 31 d2 e9 2f 04 49 00 0f 1f 44 00 00 40 0f6
> > [   36.092443] RSP: 0018:ffffc900043dfc48 EFLAGS: 00000002
> > [   36.092445] RAX: 000000000000000f RBX: ffff8881b96153e0 RCX: 000000000000038f
> > [   36.092447] RDX: 0000000000000007 RSI: 000000070000000f RDI: 000000000000038f
> > [   36.092449] RBP: 000000070000000f R08: ffffffffffffffff R09: ffff8881053bdaa8
> > [   36.092451] R10: ffff8881b9805d40 R11: 0000000000000005 R12: ffff8881b9805c00
> > [   36.092452] R13: 0000000000000000 R14: 0000000000000000 R15: ffff8881075ec970
> > [   36.092460]  ? wrmsrl+0xd/0x1b
> > [   36.092465]  ? wrmsrl+0xd/0x1b
> > [   36.092469]  </NMI>
> > [   36.092469]  <TASK>
> > [   36.092470]  __intel_pmu_enable_all.constprop.0+0x7c/0xaf
> > [   36.092475]  event_function+0xb6/0xd3
> > [   36.092478]  ? cpu_to_node+0x1a/0x1a
> > [   36.092482]  ? cpu_to_node+0x1a/0x1a
> > [   36.092485]  remote_function+0x1e/0x4c
> > [   36.092489]  generic_exec_single+0x48/0xb9
> > [   36.092492]  ? __lock_acquire+0x666/0x6ed
> > [   36.092497]  smp_call_function_single+0xbf/0x106
> > [   36.092499]  ? cpu_to_node+0x1a/0x1a
> > [   36.092504]  ? kvm_sched_clock_read+0x5/0x11
> > [   36.092508]  ? __perf_event_task_sched_in+0x13d/0x13d
> > [   36.092513]  cpu_function_call+0x47/0x69
> > [   36.092516]  ? perf_event_update_time+0x52/0x52
> > [   36.092519]  event_function_call+0x89/0x117
> > [   36.092521]  ? __perf_event_task_sched_in+0x13d/0x13d
> > [   36.092526]  ? _perf_event_disable+0x4a/0x4a
> > [   36.092528]  perf_event_for_each_child+0x3d/0x76
> > [   36.092532]  ? _perf_event_disable+0x4a/0x4a
> > [   36.092533]  _perf_ioctl+0x564/0x590
> > [   36.092537]  ? __lock_release+0xd5/0x1b0
> > [   36.092543]  ? perf_event_ctx_lock_nested+0x8e/0xba
> > [   36.092547]  perf_ioctl+0x42/0x5f
> > [   36.092551]  vfs_ioctl+0x1e/0x2f
> > [   36.092554]  __do_sys_ioctl+0x66/0x89
> > [   36.092559]  do_syscall_64+0x6d/0x84
> > [   36.092563]  entry_SYSCALL_64_after_hwframe+0x63/0xcd
> > [   36.092566] RIP: 0033:0x7fe7110f362b
> > [   36.092569] Code: 0f 1e fa 48 8b 05 5d b8 2c 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 2d b8 2c 00 f7 d8 64 89 018
> > [   36.092570] RSP: 002b:00007ffebb8e4b08 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
> > [   36.092573] RAX: ffffffffffffffda RBX: 0000000000002400 RCX: 00007fe7110f362b
> > [   36.092575] RDX: 0000000000000000 RSI: 0000000000002400 RDI: 0000000000000013
> > [   36.092576] RBP: 00007ffebb8e4b40 R08: 0000000000000001 R09: 000055c1db4a5b40
> > [   36.092577] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
> > [   36.092579] R13: 000055c1db3b2a30 R14: 0000000000000000 R15: 0000000000000000
> > [   36.092586]  </TASK>
> >
> > Cc: Alexei Starovoitov <ast@...nel.org>
> > Cc: Daniel Borkmann <daniel@...earbox.net>
> > Cc: Andrii Nakryiko <andrii@...nel.org>
> > Cc: Martin KaFai Lau <martin.lau@...ux.dev>
> > Cc: Song Liu <song@...nel.org>
> > Cc: Yonghong Song <yhs@...com>
> > Cc: John Fastabend <john.fastabend@...il.com>
> > Cc: KP Singh <kpsingh@...nel.org>
> > Cc: Stanislav Fomichev <sdf@...gle.com>
> > Cc: Hao Luo <haoluo@...gle.com>
> > Cc: Jiri Olsa <jolsa@...nel.org>
> > Signed-off-by: Tonghao Zhang <xiangxia.m.yue@...il.com>
> > ---
> >  kernel/bpf/hashtab.c | 96 +++++++++++++++++---------------------------
> >  1 file changed, 36 insertions(+), 60 deletions(-)
> >
> > diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c
> > index 22855d6ff6d3..429acd97c869 100644
> > --- a/kernel/bpf/hashtab.c
> > +++ b/kernel/bpf/hashtab.c
> > @@ -80,9 +80,6 @@ struct bucket {
> >       raw_spinlock_t raw_lock;
> >  };
> >
> > -#define HASHTAB_MAP_LOCK_COUNT 8
> > -#define HASHTAB_MAP_LOCK_MASK (HASHTAB_MAP_LOCK_COUNT - 1)
> > -
> >  struct bpf_htab {
> >       struct bpf_map map;
> >       struct bpf_mem_alloc ma;
> > @@ -104,7 +101,6 @@ struct bpf_htab {
> >       u32 elem_size;  /* size of each element in bytes */
> >       u32 hashrnd;
> >       struct lock_class_key lockdep_key;
> > -     int __percpu *map_locked[HASHTAB_MAP_LOCK_COUNT];
> >  };
> >
> >  /* each htab element is struct htab_elem + key + value */
> > @@ -146,35 +142,26 @@ static void htab_init_buckets(struct bpf_htab *htab)
> >       }
> >  }
> >
> > -static inline int htab_lock_bucket(const struct bpf_htab *htab,
> > -                                struct bucket *b, u32 hash,
> > +static inline int htab_lock_bucket(struct bucket *b,
> >                                  unsigned long *pflags)
> >  {
> >       unsigned long flags;
> >
> > -     hash = hash & HASHTAB_MAP_LOCK_MASK;
> > -
> > -     preempt_disable();
> > -     if (unlikely(__this_cpu_inc_return(*(htab->map_locked[hash])) != 1)) {
> > -             __this_cpu_dec(*(htab->map_locked[hash]));
> > -             preempt_enable();
> > -             return -EBUSY;
> > +     if (in_nmi()) {
> > +             if (!raw_spin_trylock_irqsave(&b->raw_lock, flags))
> > +                     return -EBUSY;
> > +     } else {
> > +             raw_spin_lock_irqsave(&b->raw_lock, flags);
> >       }
> >
> > -     raw_spin_lock_irqsave(&b->raw_lock, flags);
> >       *pflags = flags;
> > -
> >       return 0;
> >  }
> map_locked is also used to prevent the re-entrance of htab_lock_bucket() on the
> same CPU, so only check in_nmi() is not enough.
NMI, IRQ, and preempt may interrupt the task context.
In htab_lock_bucket, raw_spin_lock_irqsave disable the preempt and
irq. so only NMI may interrupt the codes, right ?

> > -static inline void htab_unlock_bucket(const struct bpf_htab *htab,
> > -                                   struct bucket *b, u32 hash,
> > +static inline void htab_unlock_bucket(struct bucket *b,
> >                                     unsigned long flags)
> >  {
> > -     hash = hash & HASHTAB_MAP_LOCK_MASK;
> >       raw_spin_unlock_irqrestore(&b->raw_lock, flags);
> > -     __this_cpu_dec(*(htab->map_locked[hash]));
> > -     preempt_enable();
> >  }
> >
> >  static bool htab_lru_map_delete_node(void *arg, struct bpf_lru_node *node);
> > @@ -467,7 +454,7 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
> >       bool percpu_lru = (attr->map_flags & BPF_F_NO_COMMON_LRU);
> >       bool prealloc = !(attr->map_flags & BPF_F_NO_PREALLOC);
> >       struct bpf_htab *htab;
> > -     int err, i;
> > +     int err;
> >
> >       htab = bpf_map_area_alloc(sizeof(*htab), NUMA_NO_NODE);
> >       if (!htab)
> > @@ -513,15 +500,6 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
> >       if (!htab->buckets)
> >               goto free_htab;
> >
> > -     for (i = 0; i < HASHTAB_MAP_LOCK_COUNT; i++) {
> > -             htab->map_locked[i] = bpf_map_alloc_percpu(&htab->map,
> > -                                                        sizeof(int),
> > -                                                        sizeof(int),
> > -                                                        GFP_USER);
> > -             if (!htab->map_locked[i])
> > -                     goto free_map_locked;
> > -     }
> > -
> >       if (htab->map.map_flags & BPF_F_ZERO_SEED)
> >               htab->hashrnd = 0;
> >       else
> > @@ -549,13 +527,13 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
> >       if (htab->use_percpu_counter) {
> >               err = percpu_counter_init(&htab->pcount, 0, GFP_KERNEL);
> >               if (err)
> > -                     goto free_map_locked;
> > +                     goto free_buckets;
> >       }
> >
> >       if (prealloc) {
> >               err = prealloc_init(htab);
> >               if (err)
> > -                     goto free_map_locked;
> > +                     goto free_buckets;
> >
> >               if (!percpu && !lru) {
> >                       /* lru itself can remove the least used element, so
> > @@ -568,12 +546,12 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
> >       } else {
> >               err = bpf_mem_alloc_init(&htab->ma, htab->elem_size, false);
> >               if (err)
> > -                     goto free_map_locked;
> > +                     goto free_buckets;
> >               if (percpu) {
> >                       err = bpf_mem_alloc_init(&htab->pcpu_ma,
> >                                                round_up(htab->map.value_size, 8), true);
> >                       if (err)
> > -                             goto free_map_locked;
> > +                             goto free_buckets;
> >               }
> >       }
> >
> > @@ -581,11 +559,10 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
> >
> >  free_prealloc:
> >       prealloc_destroy(htab);
> > -free_map_locked:
> > +free_buckets:
> >       if (htab->use_percpu_counter)
> >               percpu_counter_destroy(&htab->pcount);
> > -     for (i = 0; i < HASHTAB_MAP_LOCK_COUNT; i++)
> > -             free_percpu(htab->map_locked[i]);
> > +
> >       bpf_map_area_free(htab->buckets);
> >       bpf_mem_alloc_destroy(&htab->pcpu_ma);
> >       bpf_mem_alloc_destroy(&htab->ma);
> > @@ -782,7 +759,7 @@ static bool htab_lru_map_delete_node(void *arg, struct bpf_lru_node *node)
> >       b = __select_bucket(htab, tgt_l->hash);
> >       head = &b->head;
> >
> > -     ret = htab_lock_bucket(htab, b, tgt_l->hash, &flags);
> > +     ret = htab_lock_bucket(b, &flags);
> >       if (ret)
> >               return false;
> >
> > @@ -793,7 +770,7 @@ static bool htab_lru_map_delete_node(void *arg, struct bpf_lru_node *node)
> >                       break;
> >               }
> >
> > -     htab_unlock_bucket(htab, b, tgt_l->hash, flags);
> > +     htab_unlock_bucket(b, flags);
> >
> >       return l == tgt_l;
> >  }
> > @@ -1107,7 +1084,7 @@ static int htab_map_update_elem(struct bpf_map *map, void *key, void *value,
> >                */
> >       }
> >
> > -     ret = htab_lock_bucket(htab, b, hash, &flags);
> > +     ret = htab_lock_bucket(b, &flags);
> >       if (ret)
> >               return ret;
> >
> > @@ -1152,7 +1129,7 @@ static int htab_map_update_elem(struct bpf_map *map, void *key, void *value,
> >       }
> >       ret = 0;
> >  err:
> > -     htab_unlock_bucket(htab, b, hash, flags);
> > +     htab_unlock_bucket(b, flags);
> >       return ret;
> >  }
> >
> > @@ -1198,7 +1175,7 @@ static int htab_lru_map_update_elem(struct bpf_map *map, void *key, void *value,
> >       copy_map_value(&htab->map,
> >                      l_new->key + round_up(map->key_size, 8), value);
> >
> > -     ret = htab_lock_bucket(htab, b, hash, &flags);
> > +     ret = htab_lock_bucket(b, &flags);
> >       if (ret)
> >               return ret;
> >
> > @@ -1219,7 +1196,7 @@ static int htab_lru_map_update_elem(struct bpf_map *map, void *key, void *value,
> >       ret = 0;
> >
> >  err:
> > -     htab_unlock_bucket(htab, b, hash, flags);
> > +     htab_unlock_bucket(b, flags);
> >
> >       if (ret)
> >               htab_lru_push_free(htab, l_new);
> > @@ -1255,7 +1232,7 @@ static int __htab_percpu_map_update_elem(struct bpf_map *map, void *key,
> >       b = __select_bucket(htab, hash);
> >       head = &b->head;
> >
> > -     ret = htab_lock_bucket(htab, b, hash, &flags);
> > +     ret = htab_lock_bucket(b, &flags);
> >       if (ret)
> >               return ret;
> >
> > @@ -1280,7 +1257,7 @@ static int __htab_percpu_map_update_elem(struct bpf_map *map, void *key,
> >       }
> >       ret = 0;
> >  err:
> > -     htab_unlock_bucket(htab, b, hash, flags);
> > +     htab_unlock_bucket(b, flags);
> >       return ret;
> >  }
> >
> > @@ -1321,7 +1298,7 @@ static int __htab_lru_percpu_map_update_elem(struct bpf_map *map, void *key,
> >                       return -ENOMEM;
> >       }
> >
> > -     ret = htab_lock_bucket(htab, b, hash, &flags);
> > +     ret = htab_lock_bucket(b, &flags);
> >       if (ret)
> >               return ret;
> >
> > @@ -1345,7 +1322,7 @@ static int __htab_lru_percpu_map_update_elem(struct bpf_map *map, void *key,
> >       }
> >       ret = 0;
> >  err:
> > -     htab_unlock_bucket(htab, b, hash, flags);
> > +     htab_unlock_bucket(b, flags);
> >       if (l_new)
> >               bpf_lru_push_free(&htab->lru, &l_new->lru_node);
> >       return ret;
> > @@ -1384,7 +1361,7 @@ static int htab_map_delete_elem(struct bpf_map *map, void *key)
> >       b = __select_bucket(htab, hash);
> >       head = &b->head;
> >
> > -     ret = htab_lock_bucket(htab, b, hash, &flags);
> > +     ret = htab_lock_bucket(b, &flags);
> >       if (ret)
> >               return ret;
> >
> > @@ -1397,7 +1374,7 @@ static int htab_map_delete_elem(struct bpf_map *map, void *key)
> >               ret = -ENOENT;
> >       }
> >
> > -     htab_unlock_bucket(htab, b, hash, flags);
> > +     htab_unlock_bucket(b, flags);
> >       return ret;
> >  }
> >
> > @@ -1420,7 +1397,7 @@ static int htab_lru_map_delete_elem(struct bpf_map *map, void *key)
> >       b = __select_bucket(htab, hash);
> >       head = &b->head;
> >
> > -     ret = htab_lock_bucket(htab, b, hash, &flags);
> > +     ret = htab_lock_bucket(b, &flags);
> >       if (ret)
> >               return ret;
> >
> > @@ -1431,7 +1408,7 @@ static int htab_lru_map_delete_elem(struct bpf_map *map, void *key)
> >       else
> >               ret = -ENOENT;
> >
> > -     htab_unlock_bucket(htab, b, hash, flags);
> > +     htab_unlock_bucket(b, flags);
> >       if (l)
> >               htab_lru_push_free(htab, l);
> >       return ret;
> > @@ -1494,7 +1471,6 @@ static void htab_map_free_timers(struct bpf_map *map)
> >  static void htab_map_free(struct bpf_map *map)
> >  {
> >       struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
> > -     int i;
> >
> >       /* bpf_free_used_maps() or close(map_fd) will trigger this map_free callback.
> >        * bpf_free_used_maps() is called after bpf prog is no longer executing.
> > @@ -1517,10 +1493,10 @@ static void htab_map_free(struct bpf_map *map)
> >       bpf_map_area_free(htab->buckets);
> >       bpf_mem_alloc_destroy(&htab->pcpu_ma);
> >       bpf_mem_alloc_destroy(&htab->ma);
> > +
> >       if (htab->use_percpu_counter)
> >               percpu_counter_destroy(&htab->pcount);
> > -     for (i = 0; i < HASHTAB_MAP_LOCK_COUNT; i++)
> > -             free_percpu(htab->map_locked[i]);
> > +
> >       lockdep_unregister_key(&htab->lockdep_key);
> >       bpf_map_area_free(htab);
> >  }
> > @@ -1564,7 +1540,7 @@ static int __htab_map_lookup_and_delete_elem(struct bpf_map *map, void *key,
> >       b = __select_bucket(htab, hash);
> >       head = &b->head;
> >
> > -     ret = htab_lock_bucket(htab, b, hash, &bflags);
> > +     ret = htab_lock_bucket(b, &bflags);
> >       if (ret)
> >               return ret;
> >
> > @@ -1602,7 +1578,7 @@ static int __htab_map_lookup_and_delete_elem(struct bpf_map *map, void *key,
> >                       free_htab_elem(htab, l);
> >       }
> >
> > -     htab_unlock_bucket(htab, b, hash, bflags);
> > +     htab_unlock_bucket(b, bflags);
> >
> >       if (is_lru_map && l)
> >               htab_lru_push_free(htab, l);
> > @@ -1720,7 +1696,7 @@ __htab_map_lookup_and_delete_batch(struct bpf_map *map,
> >       head = &b->head;
> >       /* do not grab the lock unless need it (bucket_cnt > 0). */
> >       if (locked) {
> > -             ret = htab_lock_bucket(htab, b, batch, &flags);
> > +             ret = htab_lock_bucket(b, &flags);
> >               if (ret) {
> >                       rcu_read_unlock();
> >                       bpf_enable_instrumentation();
> > @@ -1743,7 +1719,7 @@ __htab_map_lookup_and_delete_batch(struct bpf_map *map,
> >               /* Note that since bucket_cnt > 0 here, it is implicit
> >                * that the locked was grabbed, so release it.
> >                */
> > -             htab_unlock_bucket(htab, b, batch, flags);
> > +             htab_unlock_bucket(b, flags);
> >               rcu_read_unlock();
> >               bpf_enable_instrumentation();
> >               goto after_loop;
> > @@ -1754,7 +1730,7 @@ __htab_map_lookup_and_delete_batch(struct bpf_map *map,
> >               /* Note that since bucket_cnt > 0 here, it is implicit
> >                * that the locked was grabbed, so release it.
> >                */
> > -             htab_unlock_bucket(htab, b, batch, flags);
> > +             htab_unlock_bucket(b, flags);
> >               rcu_read_unlock();
> >               bpf_enable_instrumentation();
> >               kvfree(keys);
> > @@ -1815,7 +1791,7 @@ __htab_map_lookup_and_delete_batch(struct bpf_map *map,
> >               dst_val += value_size;
> >       }
> >
> > -     htab_unlock_bucket(htab, b, batch, flags);
> > +     htab_unlock_bucket(b, flags);
> >       locked = false;
> >
> >       while (node_to_free) {
>


-- 
Best regards, Tonghao

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