linux-kernel - [PATCH 3/5] x86/MTRR: Remove wrong address check in __mtrr_type

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Date:	Mon, 11 May 2015 10:15:52 +0200
From:	Borislav Petkov <bp@...en8.de>
To:	Ingo Molnar <mingo@...nel.org>
Cc:	LKML <linux-kernel@...r.kernel.org>
Subject: [PATCH 3/5] x86/MTRR: Remove wrong address check in __mtrr_type_lookup()

From: Toshi Kani <toshi.kani@...com>

__mtrr_type_lookup() checks MTRR fixed ranges when mtrr_state.have_fixed
is set and start is less than 0x100000. However, the 'else if (start
< 0x1000000)' in the code checks with a wrong address as it has an
extra-zero in the address. The code still runs correctly as this check
is meaningless, though.

This patch replaces the wrong address check with 'else' with no
condition.

Signed-off-by: Toshi Kani <toshi.kani@...com>
Cc: linux-mm <linux-mm@...ck.org>
Cc: x86-ml <x86@...nel.org>
Cc: dave.hansen@...el.com
Cc: Elliott@...com
Cc: pebolle@...cali.nl
Cc: Andrew Morton <akpm@...ux-foundation.org>
Cc: H. Peter Anvin <hpa@...or.com>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: mingo@...hat.com
Link: http://lkml.kernel.org/r/1427234921-19737-4-git-send-email-toshi.kani@hp.com
Signed-off-by: Borislav Petkov <bp@...e.de>
---
 arch/x86/kernel/cpu/mtrr/generic.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/mtrr/generic.c b/arch/x86/kernel/cpu/mtrr/generic.c
index 7d74f7b3c6ba..5b239679cfc9 100644
--- a/arch/x86/kernel/cpu/mtrr/generic.c
+++ b/arch/x86/kernel/cpu/mtrr/generic.c
@@ -137,7 +137,7 @@ static u8 __mtrr_type_lookup(u64 start, u64 end, u64 *partial_end, int *repeat)
 			idx = 1 * 8;
 			idx += ((start - 0x80000) >> 14);
 			return mtrr_state.fixed_ranges[idx];
-		} else if (start < 0x1000000) {
+		} else {
 			idx = 3 * 8;
 			idx += ((start - 0xC0000) >> 12);
 			return mtrr_state.fixed_ranges[idx];
-- 
2.3.5

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