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: Stephen Wilson <wilsons@start.ca>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/mm/memory.c b/mm/memory.c
index 5f5b5de..5f585b6 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1486,9 +1486,9 @@
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 @@
return i ? i : -EFAULT;
BUG();
}
- if (ret & VM_FAULT_MAJOR)
- tsk->maj_flt++;
- else
- tsk->min_flt++;
+
+ 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 @@
/**
* 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