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Commit 80fbb69a authored by Glauber de Oliveira Costa's avatar Glauber de Oliveira Costa Committed by Ingo Molnar
Browse files

x86: introduce fill_ldt 



This patch introduces fill_ldt(), which populates a ldt descriptor
from a user_desc in once, instead of relying in the LDT_entry_a and
LDT_entry_b macros

Signed-off-by: default avatarGlauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 5af72502

arch/x86/kernel/ldt.c

+1 −2
Original line number Original line Diff line number Diff line
@@ -223,8 +223,7 @@ static int write_ldt(void __user *ptr, unsigned long bytecount, int oldmode) 
		}

		}

	}

	}





	ldt.a = LDT_entry_a(&ldt_info);

	fill_ldt(&ldt, &ldt_info);

	ldt.b = LDT_entry_b(&ldt_info);

	if (oldmode)

	if (oldmode)

		ldt.avl = 0;

		ldt.avl = 0;

arch/x86/kernel/process_64.c

+1 −2
Original line number Original line Diff line number Diff line
@@ -457,8 +457,7 @@ static inline void set_32bit_tls(struct task_struct *t, int tls, u32 addr) 
	};

	};

	struct desc_struct *desc = (void *)t->thread.tls_array;

	struct desc_struct *desc = (void *)t->thread.tls_array;

	desc += tls;

	desc += tls;

	desc->a = LDT_entry_a(&ud);

	fill_ldt(desc, &ud);

	desc->b = LDT_entry_b(&ud);

}

}





static inline u32 read_32bit_tls(struct task_struct *t, int tls)

static inline u32 read_32bit_tls(struct task_struct *t, int tls)

arch/x86/kernel/tls.c

+3 −4
Original line number Original line Diff line number Diff line
@@ -67,10 +67,9 @@ int do_set_thread_area(struct task_struct *p, int idx, 
	if (LDT_empty(&info)) {

	if (LDT_empty(&info)) {

		desc[0] = 0;

		desc[0] = 0;

		desc[1] = 0;

		desc[1] = 0;

	} else {

	} else

		desc[0] = LDT_entry_a(&info);

		fill_ldt((struct desc_struct *)desc, &info);

		desc[1] = LDT_entry_b(&info);



	}

	if (t == &current->thread)

	if (t == &current->thread)

		load_TLS(t, cpu);

		load_TLS(t, cpu);

include/asm-x86/desc.h

+29 −0
Original line number Original line Diff line number Diff line 
#ifndef _ASM_DESC_H_

#define _ASM_DESC_H_



#ifndef __ASSEMBLY__

#include <asm/desc_defs.h>

#include <asm/ldt.h>



static inline void fill_ldt(struct desc_struct *desc, struct user_desc *info)

{

	desc->limit0 = info->limit & 0x0ffff;

	desc->base0 = info->base_addr & 0x0000ffff;



	desc->base1 = (info->base_addr & 0x00ff0000) >> 16;

	desc->type = (info->read_exec_only ^ 1) << 1;

	desc->type |= info->contents << 2;

	desc->s = 1;

	desc->dpl = 0x3;

	desc->p = info->seg_not_present ^ 1;

	desc->limit = (info->limit & 0xf0000) >> 16;

	desc->avl = info->useable;

	desc->d = info->seg_32bit;

	desc->g = info->limit_in_pages;

	desc->base2 = (info->base_addr & 0xff000000) >> 24;

}



#endif



#ifdef CONFIG_X86_32

#ifdef CONFIG_X86_32

# include "desc_32.h"

# include "desc_32.h"

#else

#else

# include "desc_64.h"

# include "desc_64.h"

#endif

#endif



#endif

include/asm-x86/desc_32.h

+0 −15
Original line number Original line Diff line number Diff line
@@ -163,21 +163,6 @@ static inline void __set_tss_desc(unsigned int cpu, unsigned int entry, const vo 




#define set_tss_desc(cpu,addr) __set_tss_desc(cpu, GDT_ENTRY_TSS, addr)

#define set_tss_desc(cpu,addr) __set_tss_desc(cpu, GDT_ENTRY_TSS, addr)





#define LDT_entry_a(info) \

	((((info)->base_addr & 0x0000ffff) << 16) | ((info)->limit & 0x0ffff))



#define LDT_entry_b(info) \

	(((info)->base_addr & 0xff000000) | \

	(((info)->base_addr & 0x00ff0000) >> 16) | \

	((info)->limit & 0xf0000) | \

	(((info)->read_exec_only ^ 1) << 9) | \

	((info)->contents << 10) | \

	(((info)->seg_not_present ^ 1) << 15) | \

	((info)->seg_32bit << 22) | \

	((info)->limit_in_pages << 23) | \

	((info)->useable << 20) | \

	0x7000)



#define LDT_empty(info) (\

#define LDT_empty(info) (\

	(info)->base_addr	== 0	&& \

	(info)->base_addr	== 0	&& \

	(info)->limit		== 0	&& \

	(info)->limit		== 0	&& \