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: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/ldt_64.c b/arch/x86/kernel/ldt_64.c
index 6c41db3..d72dc7a 100644
--- a/arch/x86/kernel/ldt_64.c
+++ b/arch/x86/kernel/ldt_64.c
@@ -172,7 +172,7 @@
{
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 @@
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 @@
/* 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:
diff --git a/include/asm-x86/desc_64.h b/include/asm-x86/desc_64.h
index bb2009e..7d48df7 100644
--- a/include/asm-x86/desc_64.h
+++ b/include/asm-x86/desc_64.h
@@ -38,6 +38,15 @@
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)
