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-rw-r--r--mm/nommu.c33
1 files changed, 26 insertions, 7 deletions
diff --git a/mm/nommu.c b/mm/nommu.c
index 2fd2ad5da98e..53cab10fece4 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -173,8 +173,8 @@ unsigned int kobjsize(const void *objp)
173} 173}
174 174
175int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, 175int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
176 unsigned long start, int len, int flags, 176 unsigned long start, int nr_pages, int flags,
177 struct page **pages, struct vm_area_struct **vmas) 177 struct page **pages, struct vm_area_struct **vmas)
178{ 178{
179 struct vm_area_struct *vma; 179 struct vm_area_struct *vma;
180 unsigned long vm_flags; 180 unsigned long vm_flags;
@@ -189,7 +189,7 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
189 vm_flags = write ? (VM_WRITE | VM_MAYWRITE) : (VM_READ | VM_MAYREAD); 189 vm_flags = write ? (VM_WRITE | VM_MAYWRITE) : (VM_READ | VM_MAYREAD);
190 vm_flags &= force ? (VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE); 190 vm_flags &= force ? (VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE);
191 191
192 for (i = 0; i < len; i++) { 192 for (i = 0; i < nr_pages; i++) {
193 vma = find_vma(mm, start); 193 vma = find_vma(mm, start);
194 if (!vma) 194 if (!vma)
195 goto finish_or_fault; 195 goto finish_or_fault;
@@ -224,7 +224,7 @@ finish_or_fault:
224 * - don't permit access to VMAs that don't support it, such as I/O mappings 224 * - don't permit access to VMAs that don't support it, such as I/O mappings
225 */ 225 */
226int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, 226int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
227 unsigned long start, int len, int write, int force, 227 unsigned long start, int nr_pages, int write, int force,
228 struct page **pages, struct vm_area_struct **vmas) 228 struct page **pages, struct vm_area_struct **vmas)
229{ 229{
230 int flags = 0; 230 int flags = 0;
@@ -234,12 +234,31 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
234 if (force) 234 if (force)
235 flags |= GUP_FLAGS_FORCE; 235 flags |= GUP_FLAGS_FORCE;
236 236
237 return __get_user_pages(tsk, mm, 237 return __get_user_pages(tsk, mm, start, nr_pages, flags, pages, vmas);
238 start, len, flags,
239 pages, vmas);
240} 238}
241EXPORT_SYMBOL(get_user_pages); 239EXPORT_SYMBOL(get_user_pages);
242 240
241/**
242 * follow_pfn - look up PFN at a user virtual address
243 * @vma: memory mapping
244 * @address: user virtual address
245 * @pfn: location to store found PFN
246 *
247 * Only IO mappings and raw PFN mappings are allowed.
248 *
249 * Returns zero and the pfn at @pfn on success, -ve otherwise.
250 */
251int follow_pfn(struct vm_area_struct *vma, unsigned long address,
252 unsigned long *pfn)
253{
254 if (!(vma->vm_flags & (VM_IO | VM_PFNMAP)))
255 return -EINVAL;
256
257 *pfn = address >> PAGE_SHIFT;
258 return 0;
259}
260EXPORT_SYMBOL(follow_pfn);
261
243DEFINE_RWLOCK(vmlist_lock); 262DEFINE_RWLOCK(vmlist_lock);
244struct vm_struct *vmlist; 263struct vm_struct *vmlist;
245 264