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From:   zhong jiang <zhongjiang@huawei.com>
To:     <mpe@ellerman.id.au>, <paulus@samba.org>,
        <akpm@linux-foundation.org>
CC:     <npiggin@gmail.com>, <fbarrat@linux.vnet.ibm.com>,
        <fthain@telegraphics.com.au>, <linuxppc-dev@lists.ozlabs.org>,
        <linux-kernel@vger.kernel.org>
Subject: [PATCH] powerpc: xive: Move a dereference below a NULL test
Date:   Wed, 26 Sep 2018 20:09:32 +0800
Message-ID: <1537963772-15309-1-git-send-email-zhongjiang@huawei.com>
MIME-Version: 1.0
Content-Type: text/plain
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

It is safe to move dereference below a NULL test.

Signed-off-by: zhong jiang <zhongjiang@huawei.com>
---
 arch/powerpc/sysdev/xive/common.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/sysdev/xive/common.c b/arch/powerpc/sysdev/xive/common.c
index 959a2a6..9824074 100644
--- a/arch/powerpc/sysdev/xive/common.c
+++ b/arch/powerpc/sysdev/xive/common.c
@@ -1010,12 +1010,13 @@ static void xive_ipi_eoi(struct irq_data *d)
 {
 	struct xive_cpu *xc = __this_cpu_read(xive_cpu);
 
-	DBG_VERBOSE("IPI eoi: irq=%d [0x%lx] (HW IRQ 0x%x) pending=%02x\n",
-		    d->irq, irqd_to_hwirq(d), xc->hw_ipi, xc->pending_prio);
-
 	/* Handle possible race with unplug and drop stale IPIs */
 	if (!xc)
 		return;
+
+	DBG_VERBOSE("IPI eoi: irq=%d [0x%lx] (HW IRQ 0x%x) pending=%02x\n",
+		    d->irq, irqd_to_hwirq(d), xc->hw_ipi, xc->pending_prio);
+
 	xive_do_source_eoi(xc->hw_ipi, &xc->ipi_data);
 	xive_do_queue_eoi(xc);
 }
-- 
1.7.12.4