Commit 2fe6fb36 authored by Eric Dumazet's avatar Eric Dumazet Committed by Jakub Kicinski
Browse files

net: dst_cache: add two DEBUG_NET warnings 



After fixing four different bugs involving dst_cache
users, it might be worth adding a check about BH being
blocked by dst_cache callers.

DEBUG_NET_WARN_ON_ONCE(!in_softirq());

It is not fatal, if we missed valid case where no
BH deadlock is to be feared, we might change this.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Acked-by: default avatarPaolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/20240531132636.2637995-6-edumazet@google.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent cf28ff8e

net/core/dst_cache.c

+2 −0
Original line number Diff line number Diff line
@@ -27,6 +27,7 @@ struct dst_cache_pcpu { 
static void dst_cache_per_cpu_dst_set(struct dst_cache_pcpu *dst_cache,

				      struct dst_entry *dst, u32 cookie)

{

	DEBUG_NET_WARN_ON_ONCE(!in_softirq());

	dst_release(dst_cache->dst);

	if (dst)

		dst_hold(dst);
@@ -40,6 +41,7 @@ static struct dst_entry *dst_cache_per_cpu_get(struct dst_cache *dst_cache, 
{

	struct dst_entry *dst;



	DEBUG_NET_WARN_ON_ONCE(!in_softirq());

	dst = idst->dst;

	if (!dst)

		goto fail;