diff options
| author | Stephen Wilson <wilsons@start.ca> | 2011-03-13 15:49:18 -0400 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2011-03-23 16:36:56 -0400 |
| commit | e7f22e207bacdba5b73f2893a3abe935a5373e2e (patch) | |
| tree | 02e9f01788742db409587475a0aa10f3a0347e38 | |
| parent | cae5d39032acf26c265f6b1dc73d7ce6ff4bc387 (diff) | |
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>
| -rw-r--r-- | mm/memory.c | 18 |
1 files changed, 11 insertions, 7 deletions
diff --git a/mm/memory.c b/mm/memory.c index 5f5b5de5a40..5f585b65d73 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -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 (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 @@ 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 |