ARM: fix get_user_pages_fast (1ee5e87f) · Commits · 戴 / test

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

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)
		{