From: Wander Lairson Costa <wander@xxxxxxxxxx> 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@xxxxxxxxxx> --- 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
