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authorPaul Mundt <lethal@linux-sh.org>2008-02-04 22:29:59 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2008-02-05 09:44:21 -0800
commitf905bc447c303fefcb180c7e8b641746ffa6cf87 (patch)
tree390d3f3490eb6b22a40598775538dd5bbd9653c1
parentf156ac8c7aeddb2d85294b7a3b849178625e15e2 (diff)
nommu: add new vmalloc_user() and remap_vmalloc_range() interfaces.
This builds on top of the earlier vmalloc_32_user() work introduced by b50731732f926d6c49fd0724616a7344c31cd5cf, as we now have places in the nommu allmodconfig that hit up against these missing APIs. As vmalloc_32_user() is already implemented, this is moved over to vmalloc_user() and simply made a wrapper. As all current nommu platforms are 32-bit addressable, there's no special casing we have to do for ZONE_DMA and things of that nature as per GFP_VMALLOC32. remap_vmalloc_range() needs to check VM_USERMAP in order to figure out whether we permit the remap or not, which means that we also have to rework the vmalloc_user() code to grovel for the VMA and set the flag. Signed-off-by: Paul Mundt <lethal@linux-sh.org> Acked-by: David McCullough <david_mccullough@securecomputing.com> Acked-by: David Howells <dhowells@redhat.com> Acked-by: Greg Ungerer <gerg@snapgear.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--mm/nommu.c45
1 files changed, 44 insertions, 1 deletions
diff --git a/mm/nommu.c b/mm/nommu.c
index f3bfd015c40..5d8ae086f74 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -10,6 +10,7 @@
* Copyright (c) 2000-2003 David McCullough <davidm@snapgear.com>
* Copyright (c) 2000-2001 D Jeff Dionne <jeff@uClinux.org>
* Copyright (c) 2002 Greg Ungerer <gerg@snapgear.com>
+ * Copyright (c) 2007 Paul Mundt <lethal@linux-sh.org>
*/
#include <linux/module.h>
@@ -183,6 +184,26 @@ void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot)
}
EXPORT_SYMBOL(__vmalloc);
+void *vmalloc_user(unsigned long size)
+{
+ void *ret;
+
+ ret = __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO,
+ PAGE_KERNEL);
+ if (ret) {
+ struct vm_area_struct *vma;
+
+ down_write(&current->mm->mmap_sem);
+ vma = find_vma(current->mm, (unsigned long)ret);
+ if (vma)
+ vma->vm_flags |= VM_USERMAP;
+ up_write(&current->mm->mmap_sem);
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL(vmalloc_user);
+
struct page *vmalloc_to_page(const void *addr)
{
return virt_to_page(addr);
@@ -253,10 +274,17 @@ EXPORT_SYMBOL(vmalloc_32);
*
* The resulting memory area is 32bit addressable and zeroed so it can be
* mapped to userspace without leaking data.
+ *
+ * VM_USERMAP is set on the corresponding VMA so that subsequent calls to
+ * remap_vmalloc_range() are permissible.
*/
void *vmalloc_32_user(unsigned long size)
{
- return __vmalloc(size, GFP_KERNEL | __GFP_ZERO, PAGE_KERNEL);
+ /*
+ * We'll have to sort out the ZONE_DMA bits for 64-bit,
+ * but for now this can simply use vmalloc_user() directly.
+ */
+ return vmalloc_user(size);
}
EXPORT_SYMBOL(vmalloc_32_user);
@@ -1216,6 +1244,21 @@ int remap_pfn_range(struct vm_area_struct *vma, unsigned long from,
}
EXPORT_SYMBOL(remap_pfn_range);
+int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
+ unsigned long pgoff)
+{
+ unsigned int size = vma->vm_end - vma->vm_start;
+
+ if (!(vma->vm_flags & VM_USERMAP))
+ return -EINVAL;
+
+ vma->vm_start = (unsigned long)(addr + (pgoff << PAGE_SHIFT));
+ vma->vm_end = vma->vm_start + size;
+
+ return 0;
+}
+EXPORT_SYMBOL(remap_vmalloc_range);
+
void swap_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
{
}