diff options
| -rw-r--r-- | mm/nommu.c | 45 |
1 files changed, 44 insertions, 1 deletions
diff --git a/mm/nommu.c b/mm/nommu.c index f3bfd015c40b..5d8ae086f74e 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(¤t->mm->mmap_sem); + vma = find_vma(current->mm, (unsigned long)ret); + if (vma) + vma->vm_flags |= VM_USERMAP; + up_write(¤t->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) { } |