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x86: x86 user_regset TLS 

This adds accessor functions in the user_regset style for the TLS data.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Roland McGrath 2008-01-30 13:31:52 +01:00 committed by Ingo Molnar
parent 1bd5718ce5
commit 4c79a2d8e5
2 changed files with 104 additions and 6 deletions
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89
arch/x86/kernel/tls.c
View File

@ -2,6 +2,7 @@
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/user.h>
#include <linux/regset.h>
#include <asm/uaccess.h>
#include <asm/desc.h>
@ -10,6 +11,8 @@
#include <asm/processor.h>
#include <asm/proto.h>
#include "tls.h"
/*
* sys_alloc_thread_area: get a yet unused TLS descriptor index.
*/
@ -25,7 +28,7 @@ static int get_free_idx(void)
}
static void set_tls_desc(struct task_struct *p, int idx,
const struct user_desc *info)
const struct user_desc *info, int n)
{
struct thread_struct *t = &p->thread;
struct desc_struct *desc = &t->tls_array[idx - GDT_ENTRY_TLS_MIN];
@ -36,10 +39,14 @@ static void set_tls_desc(struct task_struct *p, int idx,
*/
cpu = get_cpu();
if (LDT_empty(info))
desc->a = desc->b = 0;
else
fill_ldt(desc, info);
while (n-- > 0) {
if (LDT_empty(info))
desc->a = desc->b = 0;
else
fill_ldt(desc, info);
++info;
++desc;
}
if (t == &current->thread)
load_TLS(t, cpu);
@ -77,7 +84,7 @@ int do_set_thread_area(struct task_struct *p, int idx,
if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
return -EINVAL;
set_tls_desc(p, idx, &info);
set_tls_desc(p, idx, &info, 1);
return 0;
}
@ -134,3 +141,73 @@ asmlinkage int sys_get_thread_area(struct user_desc __user *u_info)
{
return do_get_thread_area(current, -1, u_info);
}
int regset_tls_active(struct task_struct *target,
const struct user_regset *regset)
{
struct thread_struct *t = &target->thread;
int n = GDT_ENTRY_TLS_ENTRIES;
while (n > 0 && desc_empty(&t->tls_array[n - 1]))
--n;
return n;
}
int regset_tls_get(struct task_struct *target, const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
const struct desc_struct *tls;
if (pos > GDT_ENTRY_TLS_ENTRIES * sizeof(struct user_desc) ||
(pos % sizeof(struct user_desc)) != 0 ||
(count % sizeof(struct user_desc)) != 0)
return -EINVAL;
pos /= sizeof(struct user_desc);
count /= sizeof(struct user_desc);
tls = &target->thread.tls_array[pos];
if (kbuf) {
struct user_desc *info = kbuf;
while (count-- > 0)
fill_user_desc(info++, GDT_ENTRY_TLS_MIN + pos++,
tls++);
} else {
struct user_desc __user *u_info = ubuf;
while (count-- > 0) {
struct user_desc info;
fill_user_desc(&info, GDT_ENTRY_TLS_MIN + pos++, tls++);
if (__copy_to_user(u_info++, &info, sizeof(info)))
return -EFAULT;
}
}
return 0;
}
int regset_tls_set(struct task_struct *target, const struct user_regset *regset,
unsigned int pos, unsigned int count,
const void *kbuf, const void __user *ubuf)
{
struct user_desc infobuf[GDT_ENTRY_TLS_ENTRIES];
const struct user_desc *info;
if (pos > GDT_ENTRY_TLS_ENTRIES * sizeof(struct user_desc) ||
(pos % sizeof(struct user_desc)) != 0 ||
(count % sizeof(struct user_desc)) != 0)
return -EINVAL;
if (kbuf)
info = kbuf;
else if (__copy_from_user(infobuf, ubuf, count))
return -EFAULT;
else
info = infobuf;
set_tls_desc(target,
GDT_ENTRY_TLS_MIN + (pos / sizeof(struct user_desc)),
info, count / sizeof(struct user_desc));
return 0;
}

21
arch/x86/kernel/tls.h Normal file
View File

@ -0,0 +1,21 @@
/*
* Internal declarations for x86 TLS implementation functions.
*
* Copyright (C) 2007 Red Hat, Inc. All rights reserved.
*
* This copyrighted material is made available to anyone wishing to use,
* modify, copy, or redistribute it subject to the terms and conditions
* of the GNU General Public License v.2.
*
* Red Hat Author: Roland McGrath.
*/
#ifndef _ARCH_X86_KERNEL_TLS_H
#include <linux/regset.h>
extern user_regset_active_fn regset_tls_active;
extern user_regset_get_fn regset_tls_get;
extern user_regset_set_fn regset_tls_set;
#endif /* _ARCH_X86_KERNEL_TLS_H */