From: Andrew Hastings <abh@cray.com>
Date: Fri, 11 May 2007 09:23:19 +0000 (+0200)
Subject: x86_64: off-by-two error in aperture.c
X-Git-Tag: v2.6.22-rc1~26
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=547c5355d1b1167af39e315c82aa9ff1398596f4;p=linux-2.6

x86_64: off-by-two error in aperture.c

I'm using a custom BIOS to configure the northbridge GART at address
0x80000000, size 2G.  Linux complains:

"Aperture from northbridge cpu 0 beyond 4GB. Ignoring."

I think there's an off-by-two error in arch/x86_64/kernel/aperture.c:

AK: use correct types for i386

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/arch/x86_64/kernel/aperture.c b/arch/x86_64/kernel/aperture.c
index a52af58205..a3d450d6c1 100644
--- a/arch/x86_64/kernel/aperture.c
+++ b/arch/x86_64/kernel/aperture.c
@@ -86,7 +86,7 @@ static int __init aperture_valid(u64 aper_base, u32 aper_size)
 		printk("Aperture too small (%d MB)\n", aper_size>>20);
 		return 0;
 	}
-	if (aper_base + aper_size >= 0xffffffff) { 
+	if (aper_base + aper_size > 0x100000000UL) {
 		printk("Aperture beyond 4GB. Ignoring.\n");
 		return 0; 
 	}
diff --git a/arch/x86_64/kernel/pci-gart.c b/arch/x86_64/kernel/pci-gart.c
index 373ef66ca1..ae091cdc1a 100644
--- a/arch/x86_64/kernel/pci-gart.c
+++ b/arch/x86_64/kernel/pci-gart.c
@@ -476,7 +476,7 @@ static __init unsigned read_aperture(struct pci_dev *dev, u32 *size)
 	aper_base <<= 25;
 
 	aper_size = (32 * 1024 * 1024) << aper_order; 
-	if (aper_base + aper_size >= 0xffffffff || !aper_size)
+       if (aper_base + aper_size > 0x100000000UL || !aper_size)
 		aper_base = 0;
 
 	*size = aper_size;
diff --git a/drivers/char/agp/amd64-agp.c b/drivers/char/agp/amd64-agp.c
index c9f0f250d7..801abdd290 100644
--- a/drivers/char/agp/amd64-agp.c
+++ b/drivers/char/agp/amd64-agp.c
@@ -268,7 +268,7 @@ static int __devinit aperture_valid(u64 aper, u32 size)
 		printk(KERN_ERR PFX "Aperture too small (%d MB)\n", size>>20);
 		return 0;
 	}
-	if (aper + size > 0xffffffff) {
+       if ((u64)aper + size > 0x100000000ULL) {
 		printk(KERN_ERR PFX "Aperture out of bounds\n");
 		return 0;
 	}