x86: adjust/fix LDT handling for Xen
Based on patch from Jan Beulich <jbeulich@novell.com>.
Don't rely on kmalloc(PAGE_SIZE) returning PAGE_SIZE aligned memory
(Xen requires GDT *and* LDT to be page-aligned). Using the page
allocator interface also removes the (albeit small) slab allocator
overhead. The same change being done for 64-bits for consistency.
Further, the Xen hypercall interface expects the LDT address to be
virtual, not machine.
[ Adjusted to unified ldt.c - Jeremy ]
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Acked-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/kernel/ldt.c b/arch/x86/kernel/ldt.c
index b8ef462..8a7660c 100644
--- a/arch/x86/kernel/ldt.c
+++ b/arch/x86/kernel/ldt.c
@@ -12,7 +12,6 @@
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/vmalloc.h>
-#include <linux/slab.h>
#include <asm/uaccess.h>
#include <asm/system.h>
@@ -40,7 +39,7 @@
if (mincount * LDT_ENTRY_SIZE > PAGE_SIZE)
newldt = vmalloc(mincount * LDT_ENTRY_SIZE);
else
- newldt = kmalloc(mincount * LDT_ENTRY_SIZE, GFP_KERNEL);
+ newldt = (void *)__get_free_page(GFP_KERNEL);
if (!newldt)
return -ENOMEM;
@@ -78,7 +77,7 @@
if (oldsize * LDT_ENTRY_SIZE > PAGE_SIZE)
vfree(oldldt);
else
- kfree(oldldt);
+ put_page(virt_to_page(oldldt));
}
return 0;
}
@@ -129,7 +128,7 @@
if (mm->context.size * LDT_ENTRY_SIZE > PAGE_SIZE)
vfree(mm->context.ldt);
else
- kfree(mm->context.ldt);
+ put_page(virt_to_page(mm->context.ldt));
mm->context.size = 0;
}
}
