Commit c5cc87fa authored Jul 29, 2014 by Russell King

ARM: idmap: add identity mapping usage note

Add a note about the usage of the identity mapping; we do not support
accesses outside of the identity map region and kernel image while a
CPU is using the identity map. This is because the identity mapping
may overwrite vmalloc space, IO mappings, the vectors pages, etc.

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

parent 811a2407

arch/arm/mm/idmap.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -9,6 +9,11 @@
		#include <asm/sections.h>
		#include <asm/system_info.h>

		/*
		* Note: accesses outside of the kernel image and the identity map area
		* are not supported on any CPU using the idmap tables as its current
		* page tables.
		*/
		pgd_t *idmap_pgd;
		phys_addr_t (*arch_virt_to_idmap) (unsigned long x);