diff options
Diffstat (limited to 'mm/nommu.c')
| -rw-r--r-- | mm/nommu.c | 44 |
1 files changed, 33 insertions, 11 deletions
diff --git a/mm/nommu.c b/mm/nommu.c index ed75bc962fb..2696b24f2bb 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -34,6 +34,8 @@ #include <asm/tlb.h> #include <asm/tlbflush.h> +#include "internal.h" + void *high_memory; struct page *mem_map; unsigned long max_mapnr; @@ -128,20 +130,16 @@ unsigned int kobjsize(const void *objp) return PAGE_SIZE << compound_order(page); } -/* - * get a list of pages in an address range belonging to the specified process - * and indicate the VMA that covers each page - * - this is potentially dodgy as we may end incrementing the page count of a - * slab page or a secondary page from a compound page - * - don't permit access to VMAs that don't support it, such as I/O mappings - */ -int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, - unsigned long start, int len, int write, int force, - struct page **pages, struct vm_area_struct **vmas) +int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, + unsigned long start, int len, int flags, + struct page **pages, struct vm_area_struct **vmas) { struct vm_area_struct *vma; unsigned long vm_flags; int i; + int write = !!(flags & GUP_FLAGS_WRITE); + int force = !!(flags & GUP_FLAGS_FORCE); + int ignore = !!(flags & GUP_FLAGS_IGNORE_VMA_PERMISSIONS); /* calculate required read or write permissions. * - if 'force' is set, we only require the "MAY" flags. @@ -156,7 +154,7 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, /* protect what we can, including chardevs */ if (vma->vm_flags & (VM_IO | VM_PFNMAP) || - !(vm_flags & vma->vm_flags)) + (!ignore && !(vm_flags & vma->vm_flags))) goto finish_or_fault; if (pages) { @@ -174,6 +172,30 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, finish_or_fault: return i ? : -EFAULT; } + + +/* + * get a list of pages in an address range belonging to the specified process + * and indicate the VMA that covers each page + * - this is potentially dodgy as we may end incrementing the page count of a + * slab page or a secondary page from a compound page + * - don't permit access to VMAs that don't support it, such as I/O mappings + */ +int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, + unsigned long start, int len, int write, int force, + struct page **pages, struct vm_area_struct **vmas) +{ + int flags = 0; + + if (write) + flags |= GUP_FLAGS_WRITE; + if (force) + flags |= GUP_FLAGS_FORCE; + + return __get_user_pages(tsk, mm, + start, len, flags, + pages, vmas); +} EXPORT_SYMBOL(get_user_pages); DEFINE_RWLOCK(vmlist_lock); |