From: Amery Hung <ameryhung@gmail.com>
To: bpf@vger.kernel.org
Cc: netdev@vger.kernel.org, alexei.starovoitov@gmail.com,
andrii@kernel.org, daniel@iogearbox.net, memxor@gmail.com,
martin.lau@kernel.org, kpsingh@kernel.org,
yonghong.song@linux.dev, song@kernel.org, haoluo@google.com,
ameryhung@gmail.com, kernel-team@meta.com
Subject: [PATCH bpf-next v7 05/17] bpf: Change local_storage->lock and b->lock to rqspinlock
Date: Thu, 5 Feb 2026 14:29:03 -0800 [thread overview]
Message-ID: <20260205222916.1788211-6-ameryhung@gmail.com> (raw)
In-Reply-To: <20260205222916.1788211-1-ameryhung@gmail.com>
Change bpf_local_storage::lock and bpf_local_storage_map_bucket::lock
from raw_spin_lock to rqspinlock.
Finally, propagate errors from raw_res_spin_lock_irqsave() to syscall
return or BPF helper return.
In bpf_local_storage_destroy(), ignore return from
raw_res_spin_lock_irqsave() for now. A later patch will correctly
handle errors correctly in bpf_local_storage_destroy() so that it can
unlink selems even when failing to acquire locks.
For __bpf_local_storage_map_cache(), instead of handling the error,
skip updating the cache.
Signed-off-by: Amery Hung <ameryhung@gmail.com>
---
include/linux/bpf_local_storage.h | 5 ++-
kernel/bpf/bpf_local_storage.c | 64 +++++++++++++++++++++----------
2 files changed, 47 insertions(+), 22 deletions(-)
diff --git a/include/linux/bpf_local_storage.h b/include/linux/bpf_local_storage.h
index f74e0f7656a1..fa50b7afee18 100644
--- a/include/linux/bpf_local_storage.h
+++ b/include/linux/bpf_local_storage.h
@@ -15,12 +15,13 @@
#include <linux/types.h>
#include <linux/bpf_mem_alloc.h>
#include <uapi/linux/btf.h>
+#include <asm/rqspinlock.h>
#define BPF_LOCAL_STORAGE_CACHE_SIZE 16
struct bpf_local_storage_map_bucket {
struct hlist_head list;
- raw_spinlock_t lock;
+ rqspinlock_t lock;
};
/* Thp map is not the primary owner of a bpf_local_storage_elem.
@@ -94,7 +95,7 @@ struct bpf_local_storage {
* bpf_local_storage_elem.
*/
struct rcu_head rcu;
- raw_spinlock_t lock; /* Protect adding/removing from the "list" */
+ rqspinlock_t lock; /* Protect adding/removing from the "list" */
bool use_kmalloc_nolock;
};
diff --git a/kernel/bpf/bpf_local_storage.c b/kernel/bpf/bpf_local_storage.c
index 38f5c3db2957..1138e2293b50 100644
--- a/kernel/bpf/bpf_local_storage.c
+++ b/kernel/bpf/bpf_local_storage.c
@@ -321,14 +321,18 @@ static int bpf_selem_unlink_map(struct bpf_local_storage_elem *selem)
struct bpf_local_storage_map *smap;
struct bpf_local_storage_map_bucket *b;
unsigned long flags;
+ int err;
local_storage = rcu_dereference_check(selem->local_storage,
bpf_rcu_lock_held());
smap = rcu_dereference_check(SDATA(selem)->smap, bpf_rcu_lock_held());
b = select_bucket(smap, local_storage);
- raw_spin_lock_irqsave(&b->lock, flags);
+ err = raw_res_spin_lock_irqsave(&b->lock, flags);
+ if (err)
+ return err;
+
hlist_del_init_rcu(&selem->map_node);
- raw_spin_unlock_irqrestore(&b->lock, flags);
+ raw_res_spin_unlock_irqrestore(&b->lock, flags);
return 0;
}
@@ -344,11 +348,16 @@ int bpf_selem_link_map(struct bpf_local_storage_map *smap,
{
struct bpf_local_storage_map_bucket *b;
unsigned long flags;
+ int err;
b = select_bucket(smap, local_storage);
- raw_spin_lock_irqsave(&b->lock, flags);
+
+ err = raw_res_spin_lock_irqsave(&b->lock, flags);
+ if (err)
+ return err;
+
hlist_add_head_rcu(&selem->map_node, &b->list);
- raw_spin_unlock_irqrestore(&b->lock, flags);
+ raw_res_spin_unlock_irqrestore(&b->lock, flags);
return 0;
}
@@ -365,7 +374,7 @@ int bpf_selem_unlink(struct bpf_local_storage_elem *selem, bool reuse_now)
bool free_local_storage = false;
HLIST_HEAD(selem_free_list);
unsigned long flags;
- int err = 0;
+ int err;
if (unlikely(!selem_linked_to_storage_lockless(selem)))
/* selem has already been unlinked from sk */
@@ -374,7 +383,10 @@ int bpf_selem_unlink(struct bpf_local_storage_elem *selem, bool reuse_now)
local_storage = rcu_dereference_check(selem->local_storage,
bpf_rcu_lock_held());
- raw_spin_lock_irqsave(&local_storage->lock, flags);
+ err = raw_res_spin_lock_irqsave(&local_storage->lock, flags);
+ if (err)
+ return err;
+
if (likely(selem_linked_to_storage(selem))) {
/* Always unlink from map before unlinking from local_storage
* because selem will be freed after successfully unlinked from
@@ -388,7 +400,7 @@ int bpf_selem_unlink(struct bpf_local_storage_elem *selem, bool reuse_now)
local_storage, selem, &selem_free_list);
}
out:
- raw_spin_unlock_irqrestore(&local_storage->lock, flags);
+ raw_res_spin_unlock_irqrestore(&local_storage->lock, flags);
bpf_selem_free_list(&selem_free_list, reuse_now);
@@ -403,16 +415,20 @@ void __bpf_local_storage_insert_cache(struct bpf_local_storage *local_storage,
struct bpf_local_storage_elem *selem)
{
unsigned long flags;
+ int err;
/* spinlock is needed to avoid racing with the
* parallel delete. Otherwise, publishing an already
* deleted sdata to the cache will become a use-after-free
* problem in the next bpf_local_storage_lookup().
*/
- raw_spin_lock_irqsave(&local_storage->lock, flags);
+ err = raw_res_spin_lock_irqsave(&local_storage->lock, flags);
+ if (err)
+ return;
+
if (selem_linked_to_storage(selem))
rcu_assign_pointer(local_storage->cache[smap->cache_idx], SDATA(selem));
- raw_spin_unlock_irqrestore(&local_storage->lock, flags);
+ raw_res_spin_unlock_irqrestore(&local_storage->lock, flags);
}
static int check_flags(const struct bpf_local_storage_data *old_sdata,
@@ -457,14 +473,17 @@ int bpf_local_storage_alloc(void *owner,
RCU_INIT_POINTER(storage->smap, smap);
INIT_HLIST_HEAD(&storage->list);
- raw_spin_lock_init(&storage->lock);
+ raw_res_spin_lock_init(&storage->lock);
storage->owner = owner;
storage->use_kmalloc_nolock = smap->use_kmalloc_nolock;
bpf_selem_link_storage_nolock(storage, first_selem);
b = select_bucket(smap, storage);
- raw_spin_lock_irqsave(&b->lock, flags);
+ err = raw_res_spin_lock_irqsave(&b->lock, flags);
+ if (err)
+ goto uncharge;
+
bpf_selem_link_map_nolock(b, first_selem);
owner_storage_ptr =
@@ -482,11 +501,11 @@ int bpf_local_storage_alloc(void *owner,
prev_storage = cmpxchg(owner_storage_ptr, NULL, storage);
if (unlikely(prev_storage)) {
bpf_selem_unlink_map_nolock(first_selem);
- raw_spin_unlock_irqrestore(&b->lock, flags);
+ raw_res_spin_unlock_irqrestore(&b->lock, flags);
err = -EAGAIN;
goto uncharge;
}
- raw_spin_unlock_irqrestore(&b->lock, flags);
+ raw_res_spin_unlock_irqrestore(&b->lock, flags);
return 0;
@@ -569,7 +588,9 @@ bpf_local_storage_update(void *owner, struct bpf_local_storage_map *smap,
if (!alloc_selem)
return ERR_PTR(-ENOMEM);
- raw_spin_lock_irqsave(&local_storage->lock, flags);
+ err = raw_res_spin_lock_irqsave(&local_storage->lock, flags);
+ if (err)
+ goto free_selem;
/* Recheck local_storage->list under local_storage->lock */
if (unlikely(hlist_empty(&local_storage->list))) {
@@ -596,7 +617,9 @@ bpf_local_storage_update(void *owner, struct bpf_local_storage_map *smap,
b = select_bucket(smap, local_storage);
- raw_spin_lock_irqsave(&b->lock, b_flags);
+ err = raw_res_spin_lock_irqsave(&b->lock, b_flags);
+ if (err)
+ goto unlock;
alloc_selem = NULL;
/* First, link the new selem to the map */
@@ -612,9 +635,10 @@ bpf_local_storage_update(void *owner, struct bpf_local_storage_map *smap,
&old_selem_free_list);
}
- raw_spin_unlock_irqrestore(&b->lock, b_flags);
+ raw_res_spin_unlock_irqrestore(&b->lock, b_flags);
unlock:
- raw_spin_unlock_irqrestore(&local_storage->lock, flags);
+ raw_res_spin_unlock_irqrestore(&local_storage->lock, flags);
+free_selem:
bpf_selem_free_list(&old_selem_free_list, false);
if (alloc_selem) {
mem_uncharge(smap, owner, smap->elem_size);
@@ -699,7 +723,7 @@ void bpf_local_storage_destroy(struct bpf_local_storage *local_storage)
* when unlinking elem from the local_storage->list and
* the map's bucket->list.
*/
- raw_spin_lock_irqsave(&local_storage->lock, flags);
+ raw_res_spin_lock_irqsave(&local_storage->lock, flags);
hlist_for_each_entry_safe(selem, n, &local_storage->list, snode) {
/* Always unlink from map before unlinking from
* local_storage.
@@ -714,7 +738,7 @@ void bpf_local_storage_destroy(struct bpf_local_storage *local_storage)
free_storage = bpf_selem_unlink_storage_nolock(
local_storage, selem, &free_selem_list);
}
- raw_spin_unlock_irqrestore(&local_storage->lock, flags);
+ raw_res_spin_unlock_irqrestore(&local_storage->lock, flags);
bpf_selem_free_list(&free_selem_list, true);
@@ -761,7 +785,7 @@ bpf_local_storage_map_alloc(union bpf_attr *attr,
for (i = 0; i < nbuckets; i++) {
INIT_HLIST_HEAD(&smap->buckets[i].list);
- raw_spin_lock_init(&smap->buckets[i].lock);
+ raw_res_spin_lock_init(&smap->buckets[i].lock);
}
smap->elem_size = offsetof(struct bpf_local_storage_elem,
--
2.47.3
next prev parent reply other threads:[~2026-02-05 22:29 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-05 22:28 [PATCH bpf-next v7 00/17] Remove task and cgroup local storage percpu counters Amery Hung
2026-02-05 22:28 ` [PATCH bpf-next v7 01/17] bpf: Select bpf_local_storage_map_bucket based on bpf_local_storage Amery Hung
2026-02-05 22:29 ` [PATCH bpf-next v7 02/17] bpf: Convert bpf_selem_unlink_map to failable Amery Hung
2026-02-05 22:29 ` [PATCH bpf-next v7 03/17] bpf: Convert bpf_selem_link_map " Amery Hung
2026-02-05 22:29 ` [PATCH bpf-next v7 04/17] bpf: Convert bpf_selem_unlink " Amery Hung
2026-02-05 22:29 ` Amery Hung [this message]
2026-02-05 22:29 ` [PATCH bpf-next v7 06/17] bpf: Remove task local storage percpu counter Amery Hung
2026-02-05 22:29 ` [PATCH bpf-next v7 07/17] bpf: Remove cgroup " Amery Hung
2026-02-05 22:29 ` [PATCH bpf-next v7 08/17] bpf: Remove unused percpu counter from bpf_local_storage_map_free Amery Hung
2026-02-05 22:29 ` [PATCH bpf-next v7 09/17] bpf: Prepare for bpf_selem_unlink_nofail() Amery Hung
2026-02-05 22:29 ` [PATCH bpf-next v7 10/17] bpf: Support lockless unlink when freeing map or local storage Amery Hung
2026-02-06 23:25 ` Martin KaFai Lau
2026-02-05 22:29 ` [PATCH bpf-next v7 11/17] bpf: Switch to bpf_selem_unlink_nofail in bpf_local_storage_{map_free, destroy} Amery Hung
2026-02-05 22:29 ` [PATCH bpf-next v7 12/17] selftests/bpf: Update sk_storage_omem_uncharge test Amery Hung
2026-02-05 22:29 ` [PATCH bpf-next v7 13/17] selftests/bpf: Update task_local_storage/recursion test Amery Hung
2026-02-05 22:29 ` [PATCH bpf-next v7 14/17] selftests/bpf: Update task_local_storage/task_storage_nodeadlock test Amery Hung
2026-02-05 22:29 ` [PATCH bpf-next v7 15/17] selftests/bpf: Remove test_task_storage_map_stress_lookup Amery Hung
2026-02-05 22:29 ` [PATCH bpf-next v7 16/17] selftests/bpf: Choose another percpu variable in bpf for btf_dump test Amery Hung
2026-02-05 22:29 ` [PATCH bpf-next v7 17/17] selftests/bpf: Fix outdated test on storage->smap Amery Hung
2026-02-06 23:00 ` [PATCH bpf-next v7 00/17] Remove task and cgroup local storage percpu counters patchwork-bot+netdevbpf
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