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Commit 4c79a2d8 authored by Roland McGrath's avatar Roland McGrath Committed by Ingo Molnar
Browse files

x86: x86 user_regset TLS 



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

Signed-off-by: default avatarRoland McGrath <roland@redhat.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 1bd5718c

arch/x86/kernel/tls.c

+83 −6
Original line number Diff line number Diff line
@@ -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();



	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;

}

arch/x86/kernel/tls.h

0 → 100644
+21 −0
Original line number Diff line number Diff line 
/*

 * 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 */