Commit e7f22e20 authored by Stephen Wilson's avatar Stephen Wilson Committed by Al Viro
Browse files

mm: use mm_struct to resolve gate vma's in __get_user_pages 



We now check if a requested user page overlaps a gate vma using the supplied mm
instead of the supplied task.  The given task is now used solely for accounting
purposes and may be NULL.

Signed-off-by: default avatarStephen Wilson <wilsons@start.ca>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent cae5d390

mm/memory.c

+11 −7
Original line number Diff line number Diff line
@@ -1486,9 +1486,9 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, 
		struct vm_area_struct *vma;



		vma = find_extend_vma(mm, start);

		if (!vma && in_gate_area(tsk->mm, start)) {

		if (!vma && in_gate_area(mm, start)) {

			unsigned long pg = start & PAGE_MASK;

			struct vm_area_struct *gate_vma = get_gate_vma(tsk->mm);

			struct vm_area_struct *gate_vma = get_gate_vma(mm);

			pgd_t *pgd;

			pud_t *pud;

			pmd_t *pmd;
@@ -1589,10 +1589,13 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, 
						return i ? i : -EFAULT;

					BUG();

				}



				if (tsk) {

					if (ret & VM_FAULT_MAJOR)

						tsk->maj_flt++;

					else

						tsk->min_flt++;

				}



				if (ret & VM_FAULT_RETRY) {

					*nonblocking = 0;
@@ -1638,7 +1641,8 @@ EXPORT_SYMBOL(__get_user_pages); 


/**

 * get_user_pages() - pin user pages in memory

 * @tsk:	task_struct of target task

 * @tsk:	the task_struct to use for page fault accounting, or

 *		NULL if faults are not to be recorded.

 * @mm:		mm_struct of target mm

 * @start:	starting user address

 * @nr_pages:	number of pages from start to pin