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uprobes: Move alloc_page() from xol_add_vma() to xol_alloc_area()

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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>
This commit is contained in:
Oleg Nesterov 2012-12-30 17:40:39 +01:00
parent 74e59dfc6b
commit c8a8253800
1 changed files with 13 additions and 19 deletions
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32
kernel/events/uprobes.c
View file

@ -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:
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);
}