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| author |   Mike Rapoport <rppt@linux.ibm.com> | 2022-09-21 10:48:41 +0300 |
|---|---|---|
| committer |   Catalin Marinas <catalin.marinas@arm.com> | 2022-09-29 17:59:28 +0100 |
| commit | b9dd04a20f81333e4b99662f1bbaf7c9e3a1e137 (patch) | |
| tree | ea68c3c97d9a48dedd5e4858e156f7d195ec2202 | |
| parent | arm64: uaccess: simplify uaccess_mask_ptr() (diff) | |
| download | linux-dev-b9dd04a20f81333e4b99662f1bbaf7c9e3a1e137.tar.xz linux-dev-b9dd04a20f81333e4b99662f1bbaf7c9e3a1e137.zip | |
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: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/20220921074841.382615-1-rppt@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
| -rw-r--r-- | arch/arm64/mm/mmu.c | 8 | ||||
| -rw-r--r-- | arch/arm64/mm/pageattr.c | 8 |
2 files changed, 9 insertions, 7 deletions
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 69deed27dec8..e8a48dfd550f 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -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), diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c index 64e985eaa52d..d107c3d434e2 100644 --- a/arch/arm64/mm/pageattr.c +++ b/arch/arm64/mm/pageattr.c @@ -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) |