From: Jeremy Fitzhardinge <jeremy@goop.org>
Date: Sun, 27 Jul 2008 15:42:32 +0000 (-0700)
Subject: x86: fix initialization of 'l' bit in ldt descriptors
X-Git-Tag: v2.6.28-rc1~699^2^2~44
X-Git-Url: http://www.pilppa.org/gitweb/gitweb.cgi?a=commitdiff_plain;h=64f53a0492b4bc11868307990bb8f7c1e0764f89;p=linux-2.6-omap-h63xx.git

x86: fix initialization of 'l' bit in ldt descriptors

Make sure that fill_ldt() initializes the 'l' bit in the descriptor.
It always sets it to 0, ignoring 'lm' in user_desc, preserving original
x86_64 behaviour.

Previously it was leaving 'l' uninitialized.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Glauber de Oliveira Costa <gcosta@redhat.com>
---

diff --git a/include/asm-x86/desc.h b/include/asm-x86/desc.h
index 24a524f5e1a..06f786f4b4f 100644
--- a/include/asm-x86/desc.h
+++ b/include/asm-x86/desc.h
@@ -24,6 +24,11 @@ static inline void fill_ldt(struct desc_struct *desc,
 	desc->d = info->seg_32bit;
 	desc->g = info->limit_in_pages;
 	desc->base2 = (info->base_addr & 0xff000000) >> 24;
+	/*
+	 * Don't allow setting of the lm bit. It is useless anyway
+	 * because 64bit system calls require __USER_CS:
+	 */
+	desc->l = 0;
 }
 
 extern struct desc_ptr idt_descr;