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-rw-r--r--arch/i386/kernel/ldt.c4
-rw-r--r--arch/i386/kernel/traps.c3
-rw-r--r--include/asm-i386/desc.h50
-rw-r--r--include/asm-i386/mmu_context.h4
4 files changed, 22 insertions, 39 deletions
diff --git a/arch/i386/kernel/ldt.c b/arch/i386/kernel/ldt.c
index 445211eb2d57..b410e5fb034f 100644
--- a/arch/i386/kernel/ldt.c
+++ b/arch/i386/kernel/ldt.c
@@ -160,16 +160,14 @@ static int read_default_ldt(void __user * ptr, unsigned long bytecount)
{
int err;
unsigned long size;
- void *address;
err = 0;
- address = &default_ldt[0];
size = 5*sizeof(struct desc_struct);
if (size > bytecount)
size = bytecount;
err = size;
- if (copy_to_user(ptr, address, size))
+ if (clear_user(ptr, size))
err = -EFAULT;
return err;
diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c
index 48ebfab661b7..56655ea8d98f 100644
--- a/arch/i386/kernel/traps.c
+++ b/arch/i386/kernel/traps.c
@@ -61,9 +61,6 @@ int panic_on_unrecovered_nmi;
asmlinkage int system_call(void);
-struct desc_struct default_ldt[] = { { 0, 0 }, { 0, 0 }, { 0, 0 },
- { 0, 0 }, { 0, 0 } };
-
/* Do we ignore FPU interrupts ? */
char ignore_fpu_irq = 0;
diff --git a/include/asm-i386/desc.h b/include/asm-i386/desc.h
index 5874ef119ffd..a0398f780ca1 100644
--- a/include/asm-i386/desc.h
+++ b/include/asm-i386/desc.h
@@ -33,11 +33,6 @@ static inline struct desc_struct *get_cpu_gdt_table(unsigned int cpu)
return (struct desc_struct *)per_cpu(cpu_gdt_descr, cpu).address;
}
-/*
- * This is the ldt that every process will get unless we need
- * something other than this.
- */
-extern struct desc_struct default_ldt[];
extern struct desc_struct idt_table[];
extern void set_intr_gate(unsigned int irq, void * addr);
@@ -65,7 +60,6 @@ static inline void pack_gate(__u32 *a, __u32 *b,
#define DESCTYPE_S 0x10 /* !system */
#define load_TR_desc() __asm__ __volatile__("ltr %w0"::"q" (GDT_ENTRY_TSS*8))
-#define load_LDT_desc() __asm__ __volatile__("lldt %w0"::"q" (GDT_ENTRY_LDT*8))
#define load_gdt(dtr) __asm__ __volatile("lgdt %0"::"m" (*dtr))
#define load_idt(dtr) __asm__ __volatile("lidt %0"::"m" (*dtr))
@@ -115,13 +109,20 @@ static inline void __set_tss_desc(unsigned int cpu, unsigned int entry, const vo
write_gdt_entry(get_cpu_gdt_table(cpu), entry, a, b);
}
-static inline void set_ldt_desc(unsigned int cpu, void *addr, unsigned int entries)
+static inline void set_ldt(void *addr, unsigned int entries)
{
- __u32 a, b;
- pack_descriptor(&a, &b, (unsigned long)addr,
- entries * sizeof(struct desc_struct) - 1,
- DESCTYPE_LDT, 0);
- write_gdt_entry(get_cpu_gdt_table(cpu), GDT_ENTRY_LDT, a, b);
+ if (likely(entries == 0))
+ __asm__ __volatile__("lldt %w0"::"q" (0));
+ else {
+ unsigned cpu = smp_processor_id();
+ __u32 a, b;
+
+ pack_descriptor(&a, &b, (unsigned long)addr,
+ entries * sizeof(struct desc_struct) - 1,
+ DESCTYPE_LDT, 0);
+ write_gdt_entry(get_cpu_gdt_table(cpu), GDT_ENTRY_LDT, a, b);
+ __asm__ __volatile__("lldt %w0"::"q" (GDT_ENTRY_LDT*8));
+ }
}
#define set_tss_desc(cpu,addr) __set_tss_desc(cpu, GDT_ENTRY_TSS, addr)
@@ -153,35 +154,22 @@ static inline void set_ldt_desc(unsigned int cpu, void *addr, unsigned int entri
static inline void clear_LDT(void)
{
- int cpu = get_cpu();
-
- set_ldt_desc(cpu, &default_ldt[0], 5);
- load_LDT_desc();
- put_cpu();
+ set_ldt(NULL, 0);
}
/*
* load one particular LDT into the current CPU
*/
-static inline void load_LDT_nolock(mm_context_t *pc, int cpu)
+static inline void load_LDT_nolock(mm_context_t *pc)
{
- void *segments = pc->ldt;
- int count = pc->size;
-
- if (likely(!count)) {
- segments = &default_ldt[0];
- count = 5;
- }
-
- set_ldt_desc(cpu, segments, count);
- load_LDT_desc();
+ set_ldt(pc->ldt, pc->size);
}
static inline void load_LDT(mm_context_t *pc)
{
- int cpu = get_cpu();
- load_LDT_nolock(pc, cpu);
- put_cpu();
+ preempt_disable();
+ load_LDT_nolock(pc);
+ preempt_enable();
}
static inline unsigned long get_desc_base(unsigned long *desc)
diff --git a/include/asm-i386/mmu_context.h b/include/asm-i386/mmu_context.h
index 62b7bf184094..1b1495372c4d 100644
--- a/include/asm-i386/mmu_context.h
+++ b/include/asm-i386/mmu_context.h
@@ -44,7 +44,7 @@ static inline void switch_mm(struct mm_struct *prev,
* load the LDT, if the LDT is different:
*/
if (unlikely(prev->context.ldt != next->context.ldt))
- load_LDT_nolock(&next->context, cpu);
+ load_LDT_nolock(&next->context);
}
#ifdef CONFIG_SMP
else {
@@ -56,7 +56,7 @@ static inline void switch_mm(struct mm_struct *prev,
* tlb flush IPI delivery. We must reload %cr3.
*/
load_cr3(next->pgd);
- load_LDT_nolock(&next->context, cpu);
+ load_LDT_nolock(&next->context);
}
}
#endif
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