linux-kernel - [PATCH 3.16 003/410] x86, microcode: Fix accessing dis_ucode

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Message-ID: <lsq.1528380321.29558845@decadent.org.uk>
Date:   Thu, 07 Jun 2018 15:05:21 +0100
From:   Ben Hutchings <ben@...adent.org.uk>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
CC:     akpm@...ux-foundation.org, "Borislav Petkov" <bp@...e.de>,
        "Richard Hendershot" <rshendershot@...si.com>
Subject: [PATCH 3.16 003/410] x86, microcode: Fix accessing dis_ucode_ldr
 on 32-bit

3.16.57-rc1 review patch.  If anyone has any objections, please let me know.

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

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

commit 85be07c32496dc264661308e4d9d4e9ccaff8072 upstream.

We should be accessing it through a pointer, like on the BSP.

Tested-by: Richard Hendershot <rshendershot@...si.com>
Fixes: 65cef1311d5d ("x86, microcode: Add a disable chicken bit")
Signed-off-by: Borislav Petkov <bp@...e.de>
Signed-off-by: Ben Hutchings <ben@...adent.org.uk>
---
 arch/x86/kernel/cpu/microcode/core_early.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/kernel/cpu/microcode/core_early.c
+++ b/arch/x86/kernel/cpu/microcode/core_early.c
@@ -124,7 +124,7 @@ void __init load_ucode_bsp(void)
 static bool check_loader_disabled_ap(void)
 {
 #ifdef CONFIG_X86_32
-	return __pa_nodebug(dis_ucode_ldr);
+	return *((bool *)__pa_nodebug(&dis_ucode_ldr));
 #else
 	return dis_ucode_ldr;
 #endif