From 2fe6fb36c781b50482b1c3323fb526bc07d1af59 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 31 May 2024 13:26:36 +0000 Subject: [PATCH] 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: Eric Dumazet Acked-by: Paolo Abeni Link: https://lore.kernel.org/r/20240531132636.2637995-6-edumazet@google.com Signed-off-by: Jakub Kicinski --- net/core/dst_cache.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/core/dst_cache.c b/net/core/dst_cache.c index 6a0482e676d3..70c634b9e7b0 100644 --- a/net/core/dst_cache.c +++ b/net/core/dst_cache.c @@ -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;