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| author |   Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2025-05-12 11:27:26 +0200 |
|---|---|---|
| committer |   Paolo Abeni <pabeni@redhat.com> | 2025-05-15 15:23:31 +0200 |
| commit | b9eef3391de028fdd88fd7a2f81a4834fc98c9ac (patch) | |
| tree | fb4f484eb9d2268562c7036059d8f70b2d858ab0 /net/core/dev.c | |
| parent | ipv6: sr: Use nested-BH locking for hmac_storage (diff) | |
| download | wireguard-linux-b9eef3391de028fdd88fd7a2f81a4834fc98c9ac.tar.xz wireguard-linux-b9eef3391de028fdd88fd7a2f81a4834fc98c9ac.zip | |
xdp: Use nested-BH locking for system_page_pool
system_page_pool is a per-CPU variable and relies on disabled BH for its
locking. Without per-CPU locking in local_bh_disable() on PREEMPT_RT
this data structure requires explicit locking.
Make a struct with a page_pool member (original system_page_pool) and a
local_lock_t and use local_lock_nested_bh() for locking. This change
adds only lockdep coverage and does not alter the functional behaviour
for !PREEMPT_RT.
Cc: Andrew Lunn <andrew+netdev@lunn.ch>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jesper Dangaard Brouer <hawk@kernel.org>
Cc: John Fastabend <john.fastabend@gmail.com>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://patch.msgid.link/20250512092736.229935-6-bigeasy@linutronix.de
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Diffstat (limited to 'net/core/dev.c')
| -rw-r--r-- | net/core/dev.c | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index 33d5e95209cb..eea26162a585 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -462,7 +462,9 @@ EXPORT_PER_CPU_SYMBOL(softnet_data); * PP consumers must pay attention to run APIs in the appropriate context * (e.g. NAPI context). */ -DEFINE_PER_CPU(struct page_pool *, system_page_pool); +DEFINE_PER_CPU(struct page_pool_bh, system_page_pool) = { + .bh_lock = INIT_LOCAL_LOCK(bh_lock), +}; #ifdef CONFIG_LOCKDEP /* @@ -5322,7 +5324,10 @@ netif_skb_check_for_xdp(struct sk_buff **pskb, const struct bpf_prog *prog) struct sk_buff *skb = *pskb; int err, hroom, troom; - if (!skb_cow_data_for_xdp(this_cpu_read(system_page_pool), pskb, prog)) + local_lock_nested_bh(&system_page_pool.bh_lock); + err = skb_cow_data_for_xdp(this_cpu_read(system_page_pool.pool), pskb, prog); + local_unlock_nested_bh(&system_page_pool.bh_lock); + if (!err) return 0; /* In case we have to go down the path and also linearize, @@ -12712,7 +12717,7 @@ static int net_page_pool_create(int cpuid) return err; } - per_cpu(system_page_pool, cpuid) = pp_ptr; + per_cpu(system_page_pool.pool, cpuid) = pp_ptr; #endif return 0; } @@ -12842,13 +12847,13 @@ out: for_each_possible_cpu(i) { struct page_pool *pp_ptr; - pp_ptr = per_cpu(system_page_pool, i); + pp_ptr = per_cpu(system_page_pool.pool, i); if (!pp_ptr) continue; xdp_unreg_page_pool(pp_ptr); page_pool_destroy(pp_ptr); - per_cpu(system_page_pool, i) = NULL; + per_cpu(system_page_pool.pool, i) = NULL; } } |