Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit fc2d625c authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Ingo Molnar
Browse files

x86: introduce ldt_write accessor 



Create a ldt write accessor like the 32 bit one.

Preparatory patch for merging ldt.c and anyway necessary for
64bit paravirt ops.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 4edc8f54

arch/x86/kernel/ldt_64.c

+3 −5
Original line number Diff line number Diff line
@@ -172,7 +172,7 @@ static int write_ldt(void __user *ptr, unsigned long bytecount, int oldmode) 
{

	struct task_struct *me = current;

	struct mm_struct *mm = me->mm;

	__u32 entry_1, entry_2, *lp;

	__u32 entry_1, entry_2;

	int error;

	struct user_desc ldt_info;
@@ -202,8 +202,6 @@ static int write_ldt(void __user *ptr, unsigned long bytecount, int oldmode) 
			goto out_unlock;

	}



	lp = (__u32 *)((ldt_info.entry_number << 3) + (char *)mm->context.ldt);



	/* Allow LDTs to be cleared by the user. */

	if (ldt_info.base_addr == 0 && ldt_info.limit == 0) {

		if (oldmode || LDT_empty(&ldt_info)) {
@@ -220,8 +218,8 @@ static int write_ldt(void __user *ptr, unsigned long bytecount, int oldmode) 


	/* Install the new entry ...  */

install:

	*lp	= entry_1;

	*(lp+1)	= entry_2;

	write_ldt_entry(mm->context.ldt, ldt_info.entry_number, entry_1,

			entry_2);

	error = 0;



out_unlock:

include/asm-x86/desc_64.h

+9 −0
Original line number Diff line number Diff line
@@ -38,6 +38,15 @@ extern struct desc_struct default_ldt[]; 
extern struct gate_struct idt_table[];

extern struct desc_ptr cpu_gdt_descr[];



static inline void write_ldt_entry(struct desc_struct *ldt,

				   int entry, u32 entry_low, u32 entry_high)

{

	__u32 *lp = (__u32 *)((entry << 3) + (char *)ldt);



	lp[0] = entry_low;

	lp[1] = entry_high;

}



/* the cpu gdt accessor */

#define cpu_gdt(_cpu) ((struct desc_struct *)cpu_gdt_descr[_cpu].address)