Commit Graph

5 Commits

Author SHA1 Message Date
Jeremy Fitzhardinge e5e3a04289 [PATCH] i386: remove default_ldt, and simplify ldt-setting.
This patch removes the default_ldt[] array, as it has been unused since
iBCS stopped being supported.  This means it is now possible to actually
set an empty LDT segment.

In order to deal with this, the set_ldt_desc/load_LDT pair has been
replaced with a single set_ldt() operation which is responsible for both
setting up the LDT descriptor in the GDT, and reloading the LDT register.
If there are no LDT entries, the LDT register is loaded with a NULL
descriptor.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Acked-by: Zachary Amsden <zach@vmware.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
2006-12-07 02:14:01 +01:00
Uwe Zeisberger f30c226954 fix file specification in comments
Many files include the filename at the beginning, serveral used a wrong one.

Signed-off-by: Uwe Zeisberger <Uwe_Zeisberger@digi.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-10-03 23:01:26 +02:00
Adrian Bunk 8d1ed6366b [PATCH] arch/i386/kernel/ldt.c should #include <asm/mmu_context.h>
Every file should #include the header files containing the prototypes of
its global functions

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-07 07:53:29 -08:00
Zachary Amsden f2f30ebca6 [PATCH] x86: introduce a write acessor for updating the current LDT
Introduce a write acessor for updating the current LDT.  This is required
for hypervisors like Xen that do not allow LDT pages to be directly
written.

Testing - here's a fun little LDT test that can be trivially modified to
test limits as well.

/*
 * Copyright (c) 2005, Zachary Amsden (zach@vmware.com)
 * This is licensed under the GPL.
 */

#include <stdio.h>
#include <signal.h>
#include <asm/ldt.h>
#include <asm/segment.h>
#include <sys/types.h>
#include <unistd.h>
#include <sys/mman.h>
#define __KERNEL__
#include <asm/page.h>

void main(void)
{
        struct user_desc desc;
        char *code;
        unsigned long long tsc;

        code = (char *)mmap(0, 8192, PROT_EXEC|PROT_READ|PROT_WRITE,
                                 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
        desc.entry_number = 0;
        desc.base_addr = code;
        desc.limit = 1;
        desc.seg_32bit = 1;
        desc.contents = MODIFY_LDT_CONTENTS_CODE;
        desc.read_exec_only = 0;
        desc.limit_in_pages = 1;
        desc.seg_not_present = 0;
        desc.useable = 1;
        if (modify_ldt(1, &desc, sizeof(desc)) != 0) {
                perror("modify_ldt");
        }
        printf("code base is 0x%08x\n", (unsigned)code);
        code[0x0ffe] = 0x0f;  /* rdtsc */
        code[0x0fff] = 0x31;
        code[0x1000] = 0xcb;  /* lret */
        __asm__ __volatile("lcall $7,$0xffe" : "=A" (tsc));
        printf("TSC is 0x%016llx\n", tsc);
}

Signed-off-by: Zachary Amsden <zach@vmware.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:06:13 -07:00
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00