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Commit f7abb9ac authored by Shiraz Hashim's avatar Shiraz Hashim
Browse files

arm: mm: add missing pieces for CONFIG_FREE_PAGES_RDONLY 



CONFIG_FREE_PAGES_RDONLY, which marks freed kernel pages
as read-only missed the Kconfig and an interface to mark
pages as read-only for 32 bit system. Add them.

Change-Id: Ibb5020a44323fb50febd66e16ca448da8ecb352c
Signed-off-by: default avatarShiraz Hashim <shashim@codeaurora.org>
parent 154827ce

arch/arm/Kconfig.debug

+12 −0
Original line number Diff line number Diff line
@@ -86,6 +86,18 @@ config FORCE_PAGES 


          If unsure say N.



config FREE_PAGES_RDONLY

	bool "Set pages as read only while on the buddy list"

	select FORCE_PAGES

	select PAGE_POISONING

	help

          Pages are always mapped in the kernel. This means that anyone

          can write to the page if they have the address. Enable this option

          to mark pages as read only to trigger a fault if any code attempts

          to write to a page on the buddy list. This may have a performance

          impact.



          If unsure, say N.



# These options are only for real kernel hackers who want to get their hands dirty.

config DEBUG_LL

arch/arm/include/asm/cacheflush.h

+9 −0
Original line number Diff line number Diff line
@@ -539,4 +539,13 @@ static inline void secure_flush_area(const void *addr, size_t size) 
	outer_flush_range(phys, phys + size);

}



#ifdef CONFIG_FREE_PAGES_RDONLY

#define mark_addr_rdonly(a)     set_memory_ro((unsigned long)a, 1)

#define mark_addr_rdwrite(a)    set_memory_rw((unsigned long)a, 1)

#else

#define mark_addr_rdonly(a)

#define mark_addr_rdwrite(a)

#endif





#endif