* Oleg Nesterov <o...@redhat.com> [2012-12-31 18:52:16]:
> 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 <o...@redhat.com>
Acked-by: Srikar Dronamraju <sri...@linux.vnet.ibm.com>
> ---
> kernel/events/uprobes.c | 38 ++++++++++++++++----------------------
> 1 files changed, 16 insertions(+), 22 deletions(-)
>
> diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
> index 1456f7d..ef81162 100644
> --- a/kernel/events/uprobes.c
> +++ b/kernel/events/uprobes.c
> @@ -1070,27 +1070,21 @@ static int xol_add_vma(struct xol_area *area)
> 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_alloc_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 @@ static struct xol_area *xol_alloc_area(void)
> 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 @@ static unsigned long xol_get_insn_slot(struct uprobe
> *uprobe, unsigned long slot
> 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.
> --
> 1.5.5.1
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
