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From: Eric W. Biederman <ebiederm@xmission.com>
Date: Sun, 30 Jul 2006 10:03:20 +0000 (-0700)
Subject: [PATCH] machine_kexec.c: Fix the description of segment handling
X-Git-Tag: v2.6.18-rc4
X-Git-Url: http://www.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=2a8a3d5b65e86ec1dfef7d268c64a909eab94af7
[PATCH] machine_kexec.c: Fix the description of segment handling
One of my original comments in machine_kexec was unclear
and this should fix it.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Andi Kleen <ak@muc.de>
Acked-by: Horms <horms@verge.net.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---
--- a/arch/i386/kernel/machine_kexec.c
+++ b/arch/i386/kernel/machine_kexec.c
@@ -189,14 +189,11 @@ NORET_TYPE void machine_kexec(struct kim
memcpy((void *)reboot_code_buffer, relocate_new_kernel,
relocate_new_kernel_size);
- /* The segment registers are funny things, they are
- * automatically loaded from a table, in memory wherever you
- * set them to a specific selector, but this table is never
- * accessed again you set the segment to a different selector.
- *
- * The more common model is are caches where the behide
- * the scenes work is done, but is also dropped at arbitrary
- * times.
+ /* The segment registers are funny things, they have both a
+ * visible and an invisible part. Whenever the visible part is
+ * set to a specific selector, the invisible part is loaded
+ * with from a table in memory. At no other time is the
+ * descriptor table in memory accessed.
*
* I take advantage of this here by force loading the
* segments, before I zap the gdt with an invalid value.
--- a/arch/x86_64/kernel/machine_kexec.c
+++ b/arch/x86_64/kernel/machine_kexec.c
@@ -207,14 +207,11 @@ NORET_TYPE void machine_kexec(struct kim
__flush_tlb();
- /* The segment registers are funny things, they are
- * automatically loaded from a table, in memory wherever you
- * set them to a specific selector, but this table is never
- * accessed again unless you set the segment to a different selector.
- *
- * The more common model are caches where the behide
- * the scenes work is done, but is also dropped at arbitrary
- * times.
+ /* The segment registers are funny things, they have both a
+ * visible and an invisible part. Whenever the visible part is
+ * set to a specific selector, the invisible part is loaded
+ * with from a table in memory. At no other time is the
+ * descriptor table in memory accessed.
*
* I take advantage of this here by force loading the
* segments, before I zap the gdt with an invalid value.
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