linux-kernel - [PATCH 2/3] EDAC, mce_amd_inj: Move bit preparations before the injection

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Date:	Wed, 10 Jun 2015 17:33:45 +0200
From:	Borislav Petkov <bp@...en8.de>
To:	Aravind Gopalakrishnan <Aravind.Gopalakrishnan@....com>
Cc:	linux-edac <linux-edac@...r.kernel.org>,
	LKML <linux-kernel@...r.kernel.org>
Subject: [PATCH 2/3] EDAC, mce_amd_inj: Move bit preparations before the injection

From: Borislav Petkov <bp@...e.de>

We do get_online_cpus() and then start noodling with the bits. Do that
*before* we grab the hotplug lock. This accidentally fixes the other
issue where we check if a CPU is online but then go ahead and find out
the NBC core which might not be the same CPU as the CPU we want to
inject on.

Signed-off-by: Borislav Petkov <bp@...e.de>
---
 drivers/edac/mce_amd_inj.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/edac/mce_amd_inj.c b/drivers/edac/mce_amd_inj.c
index 30227f30e7c6..5001d166f54f 100644
--- a/drivers/edac/mce_amd_inj.c
+++ b/drivers/edac/mce_amd_inj.c
@@ -266,10 +266,6 @@ static void do_inject(void)
 		i_mce.status &= ~MCI_STATUS_UC;
 	}
 
-	get_online_cpus();
-	if (!cpu_online(cpu))
-		goto err;
-
 	/* prep MCE global settings for the injection */
 	mcg_status = MCG_STATUS_MCIP | MCG_STATUS_EIPV;
 
@@ -290,6 +286,10 @@ static void do_inject(void)
 		cpu = get_nbc_for_node(amd_get_nb_id(cpu));
 	}
 
+	get_online_cpus();
+	if (!cpu_online(cpu))
+		goto err;
+
 	toggle_hw_mce_inject(cpu, true);
 
 	wrmsr_on_cpu(cpu, MSR_IA32_MCG_STATUS,
-- 
2.3.5

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