linux-kernel - [PATCH 2/5] x86/pvh: Use correct size value in GDT descriptor

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Message-ID: <20240926104113.80146-9-ardb+git@google.com>
Date: Thu, 26 Sep 2024 12:41:16 +0200
From: Ard Biesheuvel <ardb+git@...gle.com>
To: linux-kernel@...r.kernel.org
Cc: Ard Biesheuvel <ardb@...nel.org>, Jason Andryuk <jason.andryuk@....com>, 
	Juergen Gross <jgross@...e.com>, Boris Ostrovsky <boris.ostrovsky@...cle.com>, x86@...nel.org, 
	xen-devel@...ts.xenproject.org
Subject: [PATCH 2/5] x86/pvh: Use correct size value in GDT descriptor

From: Ard Biesheuvel <ardb@...nel.org>

The size field in a GDT descriptor is offset by 1, so subtract 1 from
the calculated range.

Signed-off-by: Ard Biesheuvel <ardb@...nel.org>
---
 arch/x86/platform/pvh/head.S | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/platform/pvh/head.S b/arch/x86/platform/pvh/head.S
index 98ddd552885a..f09e0fb832e4 100644
--- a/arch/x86/platform/pvh/head.S
+++ b/arch/x86/platform/pvh/head.S
@@ -223,7 +223,7 @@ SYM_CODE_END(pvh_start_xen)
 	.section ".init.data","aw"
 	.balign 8
 SYM_DATA_START_LOCAL(gdt)
-	.word gdt_end - gdt_start
+	.word gdt_end - gdt_start - 1
 	.long _pa(gdt_start) /* x86-64 will overwrite if relocated. */
 	.word 0
 SYM_DATA_END(gdt)
-- 
2.46.0.792.g87dc391469-goog