5.15-stable review patch. If anyone has any objections, please let me know.
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From: Sebastian Andrzej Siewior bigeasy@linutronix.de
[ Upstream commit 1c0829788a6e6e165846b9bedd0b908ef16260b6 ]
The statistics are incremented with raw_cpu_inc() assuming it always happens with bottom half disabled. Without per-CPU locking in local_bh_disable() on PREEMPT_RT this is no longer true.
Use this_cpu_inc() on PREEMPT_RT for the increment to not worry about preemption.
Cc: David Ahern dsahern@kernel.org Signed-off-by: Sebastian Andrzej Siewior bigeasy@linutronix.de Link: https://patch.msgid.link/20250512092736.229935-4-bigeasy@linutronix.de Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- net/ipv4/route.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/net/ipv4/route.c b/net/ipv4/route.c index a4884d434038e..cbc584c386e9e 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -200,7 +200,11 @@ const __u8 ip_tos2prio[16] = { EXPORT_SYMBOL(ip_tos2prio);
static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat); +#ifndef CONFIG_PREEMPT_RT #define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field) +#else +#define RT_CACHE_STAT_INC(field) this_cpu_inc(rt_cache_stat.field) +#endif
#ifdef CONFIG_PROC_FS static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)