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Commit 9d73777e authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Linus Torvalds
Browse files

clarify get_user_pages() prototype 



Currently the 4th parameter of get_user_pages() is called len, but its
in pages, not bytes. Rename the thing to nr_pages to avoid future
confusion.

Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent ab420e6d

include/linux/mm.h

+1 −1
Original line number Diff line number Diff line
@@ -826,7 +826,7 @@ extern int make_pages_present(unsigned long addr, unsigned long end); 
extern int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write);



int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,

			unsigned long start, int len, int write, int force,

			unsigned long start, int nr_pages, int write, int force,

			struct page **pages, struct vm_area_struct **vmas);

int get_user_pages_fast(unsigned long start, int nr_pages, int write,

			struct page **pages);

mm/memory.c

+12 −14
Original line number Diff line number Diff line
@@ -1207,7 +1207,7 @@ static inline int use_zero_page(struct vm_area_struct *vma) 




int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,

		     unsigned long start, int len, int flags,

		     unsigned long start, int nr_pages, int flags,

		     struct page **pages, struct vm_area_struct **vmas)

{

	int i;
@@ -1217,7 +1217,7 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, 
	int ignore = !!(flags & GUP_FLAGS_IGNORE_VMA_PERMISSIONS);

	int ignore_sigkill = !!(flags & GUP_FLAGS_IGNORE_SIGKILL);



	if (len <= 0)

	if (nr_pages <= 0)

		return 0;

	/* 

	 * Require read or write permissions.
@@ -1269,7 +1269,7 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, 
				vmas[i] = gate_vma;

			i++;

			start += PAGE_SIZE;

			len--;

			nr_pages--;

			continue;

		}
@@ -1280,7 +1280,7 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, 


		if (is_vm_hugetlb_page(vma)) {

			i = follow_hugetlb_page(mm, vma, pages, vmas,

						&start, &len, i, write);

						&start, &nr_pages, i, write);

			continue;

		}
@@ -1357,9 +1357,9 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, 
				vmas[i] = vma;

			i++;

			start += PAGE_SIZE;

			len--;

		} while (len && start < vma->vm_end);

	} while (len);

			nr_pages--;

		} while (nr_pages && start < vma->vm_end);

	} while (nr_pages);

	return i;

}
@@ -1368,7 +1368,7 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, 
 * @tsk:	task_struct of target task

 * @mm:		mm_struct of target mm

 * @start:	starting user address

 * @len:	number of pages from start to pin

 * @nr_pages:	number of pages from start to pin

 * @write:	whether pages will be written to by the caller

 * @force:	whether to force write access even if user mapping is

 *		readonly. This will result in the page being COWed even
@@ -1380,7 +1380,7 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, 
 *		Or NULL if the caller does not require them.

 *

 * Returns number of pages pinned. This may be fewer than the number

 * requested. If len is 0 or negative, returns 0. If no pages

 * requested. If nr_pages is 0 or negative, returns 0. If no pages

 * were pinned, returns -errno. Each page returned must be released

 * with a put_page() call when it is finished with. vmas will only

 * remain valid while mmap_sem is held.
@@ -1414,7 +1414,7 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, 
 * See also get_user_pages_fast, for performance critical applications.

 */

int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,

		unsigned long start, int len, int write, int force,

		unsigned long start, int nr_pages, int write, int force,

		struct page **pages, struct vm_area_struct **vmas)

{

	int flags = 0;
@@ -1424,9 +1424,7 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, 
	if (force)

		flags |= GUP_FLAGS_FORCE;



	return __get_user_pages(tsk, mm,

				start, len, flags,

				pages, vmas);

	return __get_user_pages(tsk, mm, start, nr_pages, flags, pages, vmas);

}



EXPORT_SYMBOL(get_user_pages);

mm/nommu.c

+5 −7
Original line number Diff line number Diff line
@@ -173,7 +173,7 @@ unsigned int kobjsize(const void *objp) 
}



int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,

		     unsigned long start, int len, int flags,

		     unsigned long start, int nr_pages, int flags,

		     struct page **pages, struct vm_area_struct **vmas)

{

	struct vm_area_struct *vma;
@@ -189,7 +189,7 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, 
	vm_flags  = write ? (VM_WRITE | VM_MAYWRITE) : (VM_READ | VM_MAYREAD);

	vm_flags &= force ? (VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE);



	for (i = 0; i < len; i++) {

	for (i = 0; i < nr_pages; i++) {

		vma = find_vma(mm, start);

		if (!vma)

			goto finish_or_fault;
@@ -224,7 +224,7 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, 
 * - 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,

	unsigned long start, int nr_pages, int write, int force,

	struct page **pages, struct vm_area_struct **vmas)

{

	int flags = 0;
@@ -234,9 +234,7 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, 
	if (force)

		flags |= GUP_FLAGS_FORCE;



	return __get_user_pages(tsk, mm,

				start, len, flags,

				pages, vmas);

	return __get_user_pages(tsk, mm, start, nr_pages, flags, pages, vmas);

}

EXPORT_SYMBOL(get_user_pages);