Commit b9dd04a2 authored by Mike Rapoport's avatar Mike Rapoport Committed by Catalin Marinas
Browse files

arm64/mm: fold check for KFENCE into can_set_direct_map() 



KFENCE requires linear map to be mapped at page granularity, so that it
is possible to protect/unprotect single pages, just like with
rodata_full and DEBUG_PAGEALLOC.

Instead of repating

	can_set_direct_map() || IS_ENABLED(CONFIG_KFENCE)

make can_set_direct_map() handle the KFENCE case.

This also prevents potential false positives in kernel_page_present()
that may return true for non-present page if CONFIG_KFENCE is enabled.

Signed-off-by: default avatarMike Rapoport <rppt@linux.ibm.com>
Reviewed-by: default avatarAnshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/20220921074841.382615-1-rppt@kernel.org


Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 2305b809

arch/arm64/mm/mmu.c

+2 −6
Original line number Diff line number Diff line
@@ -535,7 +535,7 @@ static void __init map_mem(pgd_t *pgdp) 
	 */

	BUILD_BUG_ON(pgd_index(direct_map_end - 1) == pgd_index(direct_map_end));



	if (can_set_direct_map() || IS_ENABLED(CONFIG_KFENCE))

	if (can_set_direct_map())

		flags |= NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS;



	/*
@@ -1542,11 +1542,7 @@ int arch_add_memory(int nid, u64 start, u64 size, 


	VM_BUG_ON(!mhp_range_allowed(start, size, true));



	/*

	 * KFENCE requires linear map to be mapped at page granularity, so that

	 * it is possible to protect/unprotect single pages in the KFENCE pool.

	 */

	if (can_set_direct_map() || IS_ENABLED(CONFIG_KFENCE))

	if (can_set_direct_map())

		flags |= NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS;



	__create_pgd_mapping(swapper_pg_dir, start, __phys_to_virt(start),

arch/arm64/mm/pageattr.c

+7 −1
Original line number Diff line number Diff line
@@ -21,7 +21,13 @@ bool rodata_full __ro_after_init = IS_ENABLED(CONFIG_RODATA_FULL_DEFAULT_ENABLED 


bool can_set_direct_map(void)

{

	return rodata_full || debug_pagealloc_enabled();

	/*

	 * rodata_full, DEBUG_PAGEALLOC and KFENCE require linear map to be

	 * mapped at page granularity, so that it is possible to

	 * protect/unprotect single pages.

	 */

	return rodata_full || debug_pagealloc_enabled() ||

		IS_ENABLED(CONFIG_KFENCE);

}



static int change_page_range(pte_t *ptep, unsigned long addr, void *data)