x86/paravirt/xen: properly fill out the ldt ops

LTP testing showed that Xen does not properly implement
sys_modify_ldt().  This patch does the final little bits needed to
make the ldt work properly.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 8 insertions, 1 deletions

diff --git a/arch/x86/kernel/ldt.c b/arch/x86/kernel/ldt.c
index 3fee2aa50f3f..4895e0634d22 100644
--- a/arch/x86/kernel/ldt.c
+++ b/arch/x86/kernel/ldt.c
@@ -51,6 +51,8 @@ static int alloc_ldt(mm_context_t *pc, int mincount, int reload)
         memset(newldt + oldsize * LDT_ENTRY_SIZE, 0,
                (mincount - oldsize) * LDT_ENTRY_SIZE);
 
+        paravirt_alloc_ldt(newldt, mincount);
+
 #ifdef CONFIG_X86_64
         /* CHECKME: Do we really need this ? */
         wmb();
@@ -75,6 +77,7 @@ static int alloc_ldt(mm_context_t *pc, int mincount, int reload)
 #endif
         }
         if (oldsize) {
+                paravirt_free_ldt(oldldt, oldsize);
                 if (oldsize * LDT_ENTRY_SIZE > PAGE_SIZE)
                         vfree(oldldt);
                 else
@@ -86,10 +89,13 @@ static int alloc_ldt(mm_context_t *pc, int mincount, int reload)
 static inline int copy_ldt(mm_context_t *new, mm_context_t *old)
 {
         int err = alloc_ldt(new, old->size, 0);
+        int i;
 
         if (err < 0)
                 return err;
-        memcpy(new->ldt, old->ldt, old->size * LDT_ENTRY_SIZE);
+
+        for(i = 0; i < old->size; i++)
+                write_ldt_entry(new->ldt, i, old->ldt + i * LDT_ENTRY_SIZE);
         return 0;
 }
 
@@ -126,6 +132,7 @@ void destroy_context(struct mm_struct *mm)
                 if (mm == current->active_mm)
                         clear_LDT();
 #endif
+                paravirt_free_ldt(mm->context.ldt, mm->context.size);
                 if (mm->context.size * LDT_ENTRY_SIZE > PAGE_SIZE)
                         vfree(mm->context.ldt);
                 else