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

[David Miller]

From: Oleg Nesterov <oleg at redhat.com>
Date: Wed, 16 Apr 2014 21:18:25 +0200

> The last question... area->page = alloc_page(GFP_HIGHUSER), and I am
> not sure that arch/arm/mm/highmem.c:kmap_atomic() can't break the
> aliasing, __fix_to_virt() in this case will use the same (per-cpu) idx.
> 
> Looks like, __kunmap_atomic()->__cpuc_flush_dcache_area() should take
> care, but could you please ack/nack my understanding?

Good point, it might therefore make sense to use a low-mem page.