uprobes: Move alloc_page() from xol_add_vma() to xol_alloc_area()
Move alloc_page() from xol_add_vma() to xol_alloc_area() to cleanup
the code. This separates the memory allocations and consolidates the
-EALREADY cleanups and the error handling.
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 f1b8078..ea2e2a8 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -1041,22 +1041,14 @@
/* Slot allocation for XOL */
static int xol_add_vma(struct xol_area *area)
{
- struct mm_struct *mm;
- int ret;
-
- area->page = alloc_page(GFP_HIGHUSER);
- if (!area->page)
- return -ENOMEM;
-
- ret = -EALREADY;
- mm = current->mm;
+ struct mm_struct *mm = current->mm;
+ int ret = -EALREADY;
down_write(&mm->mmap_sem);
if (mm->uprobes_state.xol_area)
goto fail;
ret = -ENOMEM;
-
/* Try to map as high as possible, this is only a hint. */
area->vaddr = get_unmapped_area(NULL, TASK_SIZE - PAGE_SIZE, PAGE_SIZE, 0, 0);
if (area->vaddr & ~PAGE_MASK) {
@@ -1072,11 +1064,8 @@
smp_wmb(); /* pairs with get_xol_area() */
mm->uprobes_state.xol_area = area;
ret = 0;
-
-fail:
+ fail:
up_write(&mm->mmap_sem);
- if (ret)
- __free_page(area->page);
return ret;
}
@@ -1104,21 +1093,26 @@
area = kzalloc(sizeof(*area), GFP_KERNEL);
if (unlikely(!area))
- return NULL;
+ goto out;
area->bitmap = kzalloc(BITS_TO_LONGS(UINSNS_PER_PAGE) * sizeof(long), GFP_KERNEL);
-
if (!area->bitmap)
- goto fail;
+ goto free_area;
+
+ area->page = alloc_page(GFP_HIGHUSER);
+ if (!area->page)
+ goto free_bitmap;
init_waitqueue_head(&area->wq);
if (!xol_add_vma(area))
return area;
-fail:
+ __free_page(area->page);
+ free_bitmap:
kfree(area->bitmap);
+ free_area:
kfree(area);
-
+ out:
return get_xol_area(current->mm);
}
