From: Vivek Goyal <vgoyal@in.ibm.com>
To: linux kernel mailing list <linux-kernel@vger.kernel.org>
Cc: Reloc Kernel List <fastboot@lists.osdl.org>,
ebiederm@xmission.com, akpm@linux-foundation.org, ak@suse.de,
hpa@zytor.com, magnus.damm@gmail.com, lwang@redhat.com,
dzickus@redhat.com, pavel@suse.cz, rjw@sisk.pl
Subject: [PATCH 6/20] x86_64: cleanup segments
Date: Wed, 7 Mar 2007 12:36:25 +0530 [thread overview]
Message-ID: <20070307070625.GG23412@in.ibm.com> (raw)
In-Reply-To: <20070307065703.GA23412@in.ibm.com>
Move __KERNEL32_CS up into the unused gdt entry. __KERNEL32_CS is
used when entering the kernel so putting it first is useful when
trying to keep boot gdt sizes to a minimum.
Set the accessed bit on all gdt entries. We don't care
so there is no need for the cpu to burn the extra cycles,
and it potentially allows the pages to be immutable. Plus
it is confusing when debugging and your gdt entries mysteriously
change.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
---
arch/x86_64/kernel/head.S | 12 ++++++------
include/asm-x86_64/segment.h | 2 +-
2 files changed, 7 insertions(+), 7 deletions(-)
diff -puN arch/x86_64/kernel/head.S~x86_64-cleanup-segments arch/x86_64/kernel/head.S
--- linux-2.6.21-rc2-reloc/arch/x86_64/kernel/head.S~x86_64-cleanup-segments 2007-03-07 01:24:53.000000000 +0530
+++ linux-2.6.21-rc2-reloc-root/arch/x86_64/kernel/head.S 2007-03-07 01:24:53.000000000 +0530
@@ -362,13 +362,13 @@ gdt:
ENTRY(cpu_gdt_table)
.quad 0x0000000000000000 /* NULL descriptor */
+ .quad 0x00cf9b000000ffff /* __KERNEL32_CS */
+ .quad 0x00af9b000000ffff /* __KERNEL_CS */
+ .quad 0x00cf93000000ffff /* __KERNEL_DS */
+ .quad 0x00cffb000000ffff /* __USER32_CS */
+ .quad 0x00cff3000000ffff /* __USER_DS, __USER32_DS */
+ .quad 0x00affb000000ffff /* __USER_CS */
.quad 0x0 /* unused */
- .quad 0x00af9a000000ffff /* __KERNEL_CS */
- .quad 0x00cf92000000ffff /* __KERNEL_DS */
- .quad 0x00cffa000000ffff /* __USER32_CS */
- .quad 0x00cff2000000ffff /* __USER_DS, __USER32_DS */
- .quad 0x00affa000000ffff /* __USER_CS */
- .quad 0x00cf9a000000ffff /* __KERNEL32_CS */
.quad 0,0 /* TSS */
.quad 0,0 /* LDT */
.quad 0,0,0 /* three TLS descriptors */
diff -puN include/asm-x86_64/segment.h~x86_64-cleanup-segments include/asm-x86_64/segment.h
--- linux-2.6.21-rc2-reloc/include/asm-x86_64/segment.h~x86_64-cleanup-segments 2007-03-07 01:24:53.000000000 +0530
+++ linux-2.6.21-rc2-reloc-root/include/asm-x86_64/segment.h 2007-03-07 01:24:53.000000000 +0530
@@ -6,7 +6,7 @@
#define __KERNEL_CS 0x10
#define __KERNEL_DS 0x18
-#define __KERNEL32_CS 0x38
+#define __KERNEL32_CS 0x08
/*
* we cannot use the same code segment descriptor for user and kernel
_
next prev parent reply other threads:[~2007-03-07 7:31 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-03-07 6:57 [PATCH 0/20] x86_64 Relocatable bzImage support (V4) Vivek Goyal
2007-03-07 6:59 ` [PATCH 1/20] x86_64: Assembly safe page.h and pgtable.h Vivek Goyal
2007-03-07 19:24 ` Sam Ravnborg
2007-03-08 6:01 ` Vivek Goyal
2007-03-08 6:16 ` Eric W. Biederman
2007-03-07 7:00 ` [PATCH 2/20] x86_64: Kill temp boot pmds Vivek Goyal
2007-03-07 7:02 ` [PATCH 3/20] x86_64: Clean up the early boot page table Vivek Goyal
2007-03-07 7:03 ` [PATCH 4/20] x86_64: Fix early printk to use standard ISA mapping Vivek Goyal
2007-03-07 7:04 ` [PATCH 5/20] x86_64: modify copy_bootdata to use virtual addresses Vivek Goyal
2007-03-07 7:06 ` Vivek Goyal [this message]
2007-03-07 7:08 ` [PATCH 7/20] x86_64: Add EFER to the register set saved by save_processor_state Vivek Goyal
2007-03-07 7:09 ` [PATCH 8/20] x86_64: 64bit PIC SMP trampoline Vivek Goyal
2007-03-07 7:10 ` [PATCH 9/20] x86_64: Get rid of dead code in suspend resume Vivek Goyal
2007-03-07 7:12 ` [PATCH 10/20] x86_64: wakeup.S rename registers to reflect right names Vivek Goyal
2007-03-07 22:30 ` Pavel Machek
2007-03-07 7:13 ` [PATCH 11/20] x86_64: wakeup.S misc cleanups Vivek Goyal
2007-03-07 22:40 ` Pavel Machek
2007-03-08 4:25 ` Vivek Goyal
2007-03-07 22:41 ` Pavel Machek
2007-03-08 4:29 ` Vivek Goyal
2007-03-08 11:43 ` Pavel Machek
2007-03-08 16:45 ` [Fastboot] " Lombard, David N
2007-03-07 7:14 ` [PATCH 12/20] x86_64: 64bit ACPI wakeup trampoline Vivek Goyal
2007-03-07 22:45 ` Pavel Machek
2007-03-07 22:57 ` [Fastboot] " Bernhard Walle
2007-03-08 4:58 ` Vivek Goyal
2007-03-08 11:44 ` Pavel Machek
2007-03-07 7:16 ` [PATCH 13/20] x86_64: Modify discover_ebda to use virtual addresses Vivek Goyal
2007-03-07 7:17 ` [PATCH 14/20] x86_64: Remove the identity mapping as early as possible Vivek Goyal
2007-03-07 7:18 ` [PATCH 15/20] Move swsusp __pa() dependent code to arch portion Vivek Goyal
2007-03-07 22:47 ` Pavel Machek
2007-03-08 5:34 ` Vivek Goyal
2007-03-08 11:47 ` Pavel Machek
2007-03-07 7:20 ` [PATCH 16/20] swsusp: do not use virt_to_page on kernel data address Vivek Goyal
2007-03-07 22:49 ` Pavel Machek
2007-03-08 5:17 ` Vivek Goyal
2007-03-08 11:47 ` Pavel Machek
2007-03-07 22:50 ` Pavel Machek
2007-03-07 23:15 ` Nigel Cunningham
2007-03-08 5:04 ` Vivek Goyal
2007-03-08 11:44 ` Pavel Machek
2007-03-07 7:21 ` [PATCH 17/20] x86_64: __pa and __pa_symbol address space separation Vivek Goyal
2007-03-07 7:22 ` [PATCH 18/20] x86_64: Relocatable Kernel Support Vivek Goyal
2007-03-07 7:24 ` [PATCH 19/20] x86_64: Extend bzImage protocol for relocatable bzImage Vivek Goyal
2007-03-07 7:25 ` [PATCH 20/20] x86_64: Move cpu verification code to common file Vivek Goyal
2007-03-07 15:07 ` [PATCH 0/20] x86_64 Relocatable bzImage support (V4) Arjan van de Ven
2007-03-07 19:08 ` Eric W. Biederman
2007-03-07 20:49 ` Nigel Cunningham
2007-03-07 23:15 ` Nigel Cunningham
2007-03-08 4:40 ` Vivek Goyal
2007-03-08 8:07 ` Nigel Cunningham
2007-03-08 8:27 ` Vivek Goyal
2007-03-08 7:48 ` Vivek Goyal
2007-03-08 3:36 ` Vivek Goyal
2007-03-14 23:10 ` Andi Kleen
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