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Commit 1ee5e87f authored by Russell King's avatar Russell King
Browse files

ARM: fix get_user_pages_fast 



Ensure that get_user_pages_fast() is not able to access memory which
has been mapped with PROT_NONE.

Reported-by: default avatarAl Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: default avatarRussell King <rmk+kernel@armlinux.org.uk>
parent b9dd05c7

arch/arm/include/asm/pgtable.h

+12 −0
Original line number Diff line number Diff line
@@ -232,6 +232,18 @@ static inline pte_t *pmd_page_vaddr(pmd_t pmd) 
#define pte_valid_user(pte)	\

	(pte_valid(pte) && pte_isset((pte), L_PTE_USER) && pte_young(pte))



static inline bool pte_access_permitted(pte_t pte, bool write)

{

	pteval_t mask = L_PTE_PRESENT | L_PTE_USER;

	pteval_t needed = mask;



	if (write)

		mask |= L_PTE_RDONLY;



	return (pte_val(pte) & mask) == needed;

}

#define pte_access_permitted pte_access_permitted



#if __LINUX_ARM_ARCH__ < 6

static inline void __sync_icache_dcache(pte_t pteval)

{