perf: Fix get_recursion_context()

stable inclusion
from linux-4.19.158
commit 0f4eb125c56b524776a2f396bb7a7c119bb2e0a1

--------------------------------

[ Upstream commit ce0f17fc ]

One should use in_serving_softirq() to detect SoftIRQ context.

Fixes: 96f6d444 ("perf_counter: avoid recursion")
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201030151955.120572175@infradead.orgSigned-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
Signed-off-by: NCheng Jian <cj.chengjian@huawei.com>

kernel/events/internal.h

@@ -209,7 +209,7 @@ static inline int get_recursion_context(int *recursion)
 		rctx = 3;
 	else if (in_irq())
 		rctx = 2;
-	else if (in_softirq())
+	else if (in_serving_softirq())
 		rctx = 1;
 	else
 		rctx = 0;