uprobes: Fold xol_alloc_area() into get_xol_area()
Currently only xol_get_insn_slot() does get_xol_area() + xol_alloc_area(),
but this will have more users and we do not want to copy-and-paste this
code. This patch simply moves xol_alloc_area() into get_xol_area() to
simplify the current and future code.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Anton Arapov <anton@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index ea2e2a8..7e3e5c5 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -1070,27 +1070,21 @@
return ret;
}
-static struct xol_area *get_xol_area(struct mm_struct *mm)
-{
- struct xol_area *area;
-
- area = mm->uprobes_state.xol_area;
- smp_read_barrier_depends(); /* pairs with wmb in xol_add_vma() */
-
- return area;
-}
-
/*
- * xol_alloc_area - Allocate process's xol_area.
- * This area will be used for storing instructions for execution out of
- * line.
+ * get_xol_area - Allocate process's xol_area if necessary.
+ * This area will be used for storing instructions for execution out of line.
*
* Returns the allocated area or NULL.
*/
-static struct xol_area *xol_alloc_area(void)
+static struct xol_area *get_xol_area(void)
{
+ struct mm_struct *mm = current->mm;
struct xol_area *area;
+ area = mm->uprobes_state.xol_area;
+ if (area)
+ goto ret;
+
area = kzalloc(sizeof(*area), GFP_KERNEL);
if (unlikely(!area))
goto out;
@@ -1113,7 +1107,10 @@
free_area:
kfree(area);
out:
- return get_xol_area(current->mm);
+ area = mm->uprobes_state.xol_area;
+ ret:
+ smp_read_barrier_depends(); /* pairs with wmb in xol_add_vma() */
+ return area;
}
/*
@@ -1189,14 +1186,11 @@
unsigned long offset;
void *vaddr;
- area = get_xol_area(current->mm);
- if (!area) {
- area = xol_alloc_area();
- if (!area)
- return 0;
- }
- current->utask->xol_vaddr = xol_take_insn_slot(area);
+ area = get_xol_area();
+ if (!area)
+ return 0;
+ current->utask->xol_vaddr = xol_take_insn_slot(area);
/*
* Initialize the slot if xol_vaddr points to valid
* instruction slot.
