On Thu, Dec 03, 2020 at 08:28:21AM -0500, Sasha Levin wrote:
From: Peter Zijlstra peterz@infradead.org
[ Upstream commit 58c644ba512cfbc2e39b758dd979edd1d6d00e27 ]
We call arch_cpu_idle() with RCU disabled, but then use local_irq_{en,dis}able(), which invokes tracing, which relies on RCU.
Switch all arch_cpu_idle() implementations to use raw_local_irq_{en,dis}able() and carefully manage the lockdep,rcu,tracing state like we do in entry.
(XXX: we really should change arch_cpu_idle() to not return with interrupts enabled)
Reported-by: Sven Schnelle svens@linux.ibm.com Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Reviewed-by: Mark Rutland mark.rutland@arm.com Tested-by: Mark Rutland mark.rutland@arm.com Link: https://lkml.kernel.org/r/20201120114925.594122626@infradead.org Signed-off-by: Sasha Levin sashal@kernel.org
This patch broke s390 irq state tracing. A patch to fix this is scheduled to be merged upstream today (hopefully). Therefore I think this patch should not yet go into 5.9 stable.