From: Wander Lairson Costa <wander@redhat.com>
write_msg(netconsole.c:836) calls netpoll_send_udp after a call to
spin_lock_irqsave, which normally disables interrupts; but in PREEMPT_RT
this call just locks an rt_mutex without disabling irqs. In this case,
netpoll_send_udp is called with interrupts enabled.
Signed-off-by: Wander Lairson Costa <wander@redhat.com>
---
net/core/netpoll.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index c310c7c1cef7..0a6b04714558 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -36,6 +36,7 @@
#include <net/ip6_checksum.h>
#include <asm/unaligned.h>
#include <trace/events/napi.h>
+#include <linux/kconfig.h>
/*
* We maintain a small pool of fully-sized skbs, to make sure the
@@ -389,7 +390,8 @@ void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
static atomic_t ip_ident;
struct ipv6hdr *ip6h;
- WARN_ON_ONCE(!irqs_disabled());
+ if (!IS_ENABLED(CONFIG_PREEMPT_RT))
+ WARN_ON_ONCE(!irqs_disabled());
udp_len = len + sizeof(*udph);
if (np->ipv6)
--
2.27.0