[RFC PATCH v4] ARM: uprobes xol write directly to userspace

[Linus Torvalds]

On Mon, Apr 21, 2014 at 9:16 AM, David Long <dave.long at linaro.org> wrote:
>
> void arch_uprobe_copy_ixol(struct page *page, unsigned long vaddr,
>                         const void *src, int len)
> {
>         void *kaddr = kmap_atomic(page);
>
> #ifdef CONFIG_SMP
>         preempt_disable();
> #endif

That #ifdef seems totally pointless. Make it unconditional, or remove
it entirely (the kmap_atomic() already causes us to be non-preemptible
in practice).

           Linus