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Commit c8a82538 authored by Oleg Nesterov's avatar Oleg Nesterov
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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: default avatarOleg Nesterov <oleg@redhat.com>
Acked-by: default avatarAnton Arapov <anton@redhat.com>
Acked-by: default avatarSrikar Dronamraju <srikar@linux.vnet.ibm.com>
parent 74e59dfc

kernel/events/uprobes.c

+13 −19
Original line number Diff line number Diff line
@@ -1041,22 +1041,14 @@ void uprobe_munmap(struct vm_area_struct *vma, unsigned long start, unsigned lon 
/* 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 @@ static int xol_add_vma(struct xol_area *area) 
	smp_wmb();	/* pairs with get_xol_area() */

	mm->uprobes_state.xol_area = area;

	ret = 0;



 fail:

	up_write(&mm->mmap_sem);

	if (ret)

		__free_page(area->page);



	return ret;

}
@@ -1104,21 +1093,26 @@ static struct xol_area *xol_alloc_area(void) 


	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);

}