linux-kernel - [PATCH 5.12 575/677] powerpc/syscall: switch user_exit_irqoff and trace_hardirqs

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Date:   Wed, 12 May 2021 16:50:21 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Nicholas Piggin <npiggin@...il.com>,
        Michael Ellerman <mpe@...erman.id.au>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH 5.12 575/677] powerpc/syscall: switch user_exit_irqoff and trace_hardirqs_off order

From: Nicholas Piggin <npiggin@...il.com>

[ Upstream commit 5a5a893c4ad897b8a36f846602895515b7407a71 ]

user_exit_irqoff() -> __context_tracking_exit -> vtime_user_exit
warns in __seqprop_assert due to lockdep thinking preemption is enabled
because trace_hardirqs_off() has not yet been called.

Switch the order of these two calls, which matches their ordering in
interrupt_enter_prepare.

Fixes: 5f0b6ac3905f ("powerpc/64/syscall: Reconcile interrupts")
Signed-off-by: Nicholas Piggin <npiggin@...il.com>
Signed-off-by: Michael Ellerman <mpe@...erman.id.au>
Link: https://lore.kernel.org/r/20210316104206.407354-2-npiggin@gmail.com
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 arch/powerpc/kernel/interrupt.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kernel/interrupt.c b/arch/powerpc/kernel/interrupt.c
index c475a229a42a..352346e14a08 100644
--- a/arch/powerpc/kernel/interrupt.c
+++ b/arch/powerpc/kernel/interrupt.c
@@ -34,11 +34,11 @@ notrace long system_call_exception(long r3, long r4, long r5,
 	if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
 		BUG_ON(irq_soft_mask_return() != IRQS_ALL_DISABLED);
 
+	trace_hardirqs_off(); /* finish reconciling */
+
 	CT_WARN_ON(ct_state() == CONTEXT_KERNEL);
 	user_exit_irqoff();
 
-	trace_hardirqs_off(); /* finish reconciling */
-
 	if (!IS_ENABLED(CONFIG_BOOKE) && !IS_ENABLED(CONFIG_40x))
 		BUG_ON(!(regs->msr & MSR_RI));
 	BUG_ON(!(regs->msr & MSR_PR));
-- 
2.30.2