X-Git-Url: http://git.cascardo.info/?a=blobdiff_plain;f=mm%2Fmlock.c;h=145a4258ddbc775d1d2acf133a21b83280a8f282;hb=d943649831aba0fcdda37a0e9e25b332a634cf5e;hp=14645be06e301cfc4a62301e25818365e766874e;hpb=f44dd184634d401f5cf88a6d8b4a60d5ff4f417f;p=cascardo%2Flinux.git

diff --git a/mm/mlock.c b/mm/mlock.c
index 14645be06e30..145a4258ddbc 100644
--- a/mm/mlock.c
+++ b/mm/mlock.c
@@ -516,6 +516,7 @@ static int mlock_fixup(struct vm_area_struct *vma, struct vm_area_struct **prev,
 	int nr_pages;
 	int ret = 0;
 	int lock = !!(newflags & VM_LOCKED);
+	vm_flags_t old_flags = vma->vm_flags;
 
 	if (newflags == vma->vm_flags || (vma->vm_flags & VM_SPECIAL) ||
 	    is_vm_hugetlb_page(vma) || vma == get_gate_vma(current->mm))
@@ -550,6 +551,8 @@ success:
 	nr_pages = (end - start) >> PAGE_SHIFT;
 	if (!lock)
 		nr_pages = -nr_pages;
+	else if (old_flags & VM_LOCKED)
+		nr_pages = 0;
 	mm->locked_vm += nr_pages;
 
 	/*
@@ -617,6 +620,45 @@ static int apply_vma_lock_flags(unsigned long start, size_t len,
 	return error;
 }
 
+/*
+ * Go through vma areas and sum size of mlocked
+ * vma pages, as return value.
+ * Note deferred memory locking case(mlock2(,,MLOCK_ONFAULT)
+ * is also counted.
+ * Return value: previously mlocked page counts
+ */
+static int count_mm_mlocked_page_nr(struct mm_struct *mm,
+		unsigned long start, size_t len)
+{
+	struct vm_area_struct *vma;
+	int count = 0;
+
+	if (mm == NULL)
+		mm = current->mm;
+
+	vma = find_vma(mm, start);
+	if (vma == NULL)
+		vma = mm->mmap;
+
+	for (; vma ; vma = vma->vm_next) {
+		if (start >= vma->vm_end)
+			continue;
+		if (start + len <=  vma->vm_start)
+			break;
+		if (vma->vm_flags & VM_LOCKED) {
+			if (start > vma->vm_start)
+				count -= (start - vma->vm_start);
+			if (start + len < vma->vm_end) {
+				count += start + len - vma->vm_start;
+				break;
+			}
+			count += vma->vm_end - vma->vm_start;
+		}
+	}
+
+	return count >> PAGE_SHIFT;
+}
+
 static __must_check int do_mlock(unsigned long start, size_t len, vm_flags_t flags)
 {
 	unsigned long locked;
@@ -639,6 +681,16 @@ static __must_check int do_mlock(unsigned long start, size_t len, vm_flags_t fla
 		return -EINTR;
 
 	locked += current->mm->locked_vm;
+	if ((locked > lock_limit) && (!capable(CAP_IPC_LOCK))) {
+		/*
+		 * It is possible that the regions requested intersect with
+		 * previously mlocked areas, that part area in "mm->locked_vm"
+		 * should not be counted to new mlock increment count. So check
+		 * and adjust locked count if necessary.
+		 */
+		locked -= count_mm_mlocked_page_nr(current->mm,
+				start, len);
+	}
 
 	/* check against resource limits */
 	if ((locked <= lock_limit) || capable(CAP_IPC_LOCK))