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-rw-r--r--mm/gup.c16
1 files changed, 13 insertions, 3 deletions
diff --git a/mm/gup.c b/mm/gup.c
index de24ef4cd1af..b935c2c71ec9 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -610,6 +610,18 @@ next_page:
}
EXPORT_SYMBOL(__get_user_pages);
+bool vma_permits_fault(struct vm_area_struct *vma, unsigned int fault_flags)
+{
+ vm_flags_t vm_flags;
+
+ vm_flags = (fault_flags & FAULT_FLAG_WRITE) ? VM_WRITE : VM_READ;
+
+ if (!(vm_flags & vma->vm_flags))
+ return false;
+
+ return true;
+}
+
/*
* fixup_user_fault() - manually resolve a user page fault
* @tsk: the task_struct to use for page fault accounting, or
@@ -645,7 +657,6 @@ int fixup_user_fault(struct task_struct *tsk, struct mm_struct *mm,
bool *unlocked)
{
struct vm_area_struct *vma;
- vm_flags_t vm_flags;
int ret, major = 0;
if (unlocked)
@@ -656,8 +667,7 @@ retry:
if (!vma || address < vma->vm_start)
return -EFAULT;
- vm_flags = (fault_flags & FAULT_FLAG_WRITE) ? VM_WRITE : VM_READ;
- if (!(vm_flags & vma->vm_flags))
+ if (!vma_permits_fault(vma, fault_flags))
return -EFAULT;
ret = handle_mm_fault(mm, vma, address, fault_flags);