diff options
| author | Joey Gouly <joey.gouly@arm.com> | 2023-06-06 15:58:50 +0100 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2023-06-06 16:52:41 +0100 |
| commit | f0af339fc408a55c9f48f5d9ca47059ef1eb36b8 (patch) | |
| tree | f71ee516598e602503bfcfea30789697cfdbcbca | |
| parent | 8ef67c67e637809a28f0efeb045aa454c7799a51 (diff) | |
arm64: add PTE_UXN/PTE_WRITE to SWAPPER_*_FLAGS
With PIE enabled, the swapper PTEs would have a Permission Indirection Index
(PIIndex) of 0. A PIIndex of 0 is not currently used by any other PTEs.
To avoid using index 0 specifically for the swapper PTEs, mark them as
PTE_UXN and PTE_WRITE, so that they map to a PAGE_KERNEL_EXEC equivalent.
This also adds PTE_WRITE to KPTI_NG_PTE_FLAGS, which was tested by booting
with kpti=on.
Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20230606145859.697944-12-joey.gouly@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
| -rw-r--r-- | arch/arm64/include/asm/kernel-pgtable.h | 8 | ||||
| -rw-r--r-- | arch/arm64/kernel/head.S | 8 | ||||
| -rw-r--r-- | arch/arm64/mm/proc.S | 4 |
3 files changed, 10 insertions, 10 deletions
diff --git a/arch/arm64/include/asm/kernel-pgtable.h b/arch/arm64/include/asm/kernel-pgtable.h index 186dd7f85b14..577773870b66 100644 --- a/arch/arm64/include/asm/kernel-pgtable.h +++ b/arch/arm64/include/asm/kernel-pgtable.h @@ -107,14 +107,14 @@ /* * Initial memory map attributes. */ -#define SWAPPER_PTE_FLAGS (PTE_TYPE_PAGE | PTE_AF | PTE_SHARED) -#define SWAPPER_PMD_FLAGS (PMD_TYPE_SECT | PMD_SECT_AF | PMD_SECT_S) +#define SWAPPER_PTE_FLAGS (PTE_TYPE_PAGE | PTE_AF | PTE_SHARED | PTE_UXN) +#define SWAPPER_PMD_FLAGS (PMD_TYPE_SECT | PMD_SECT_AF | PMD_SECT_S | PTE_UXN) #ifdef CONFIG_ARM64_4K_PAGES -#define SWAPPER_RW_MMUFLAGS (PMD_ATTRINDX(MT_NORMAL) | SWAPPER_PMD_FLAGS) +#define SWAPPER_RW_MMUFLAGS (PMD_ATTRINDX(MT_NORMAL) | SWAPPER_PMD_FLAGS | PTE_WRITE) #define SWAPPER_RX_MMUFLAGS (SWAPPER_RW_MMUFLAGS | PMD_SECT_RDONLY) #else -#define SWAPPER_RW_MMUFLAGS (PTE_ATTRINDX(MT_NORMAL) | SWAPPER_PTE_FLAGS) +#define SWAPPER_RW_MMUFLAGS (PTE_ATTRINDX(MT_NORMAL) | SWAPPER_PTE_FLAGS | PTE_WRITE) #define SWAPPER_RX_MMUFLAGS (SWAPPER_RW_MMUFLAGS | PTE_RDONLY) #endif diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index e92caebff46a..0f5a30f109d9 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -382,7 +382,7 @@ SYM_FUNC_START_LOCAL(create_idmap) adrp x0, init_idmap_pg_dir adrp x3, _text adrp x6, _end + MAX_FDT_SIZE + SWAPPER_BLOCK_SIZE - mov x7, SWAPPER_RX_MMUFLAGS + mov_q x7, SWAPPER_RX_MMUFLAGS map_memory x0, x1, x3, x6, x7, x3, IDMAP_PGD_ORDER, x10, x11, x12, x13, x14, EXTRA_SHIFT @@ -391,7 +391,7 @@ SYM_FUNC_START_LOCAL(create_idmap) adrp x2, init_pg_dir adrp x3, init_pg_end bic x4, x2, #SWAPPER_BLOCK_SIZE - 1 - mov x5, SWAPPER_RW_MMUFLAGS + mov_q x5, SWAPPER_RW_MMUFLAGS mov x6, #SWAPPER_BLOCK_SHIFT bl remap_region @@ -402,7 +402,7 @@ SYM_FUNC_START_LOCAL(create_idmap) bfi x22, x21, #0, #SWAPPER_BLOCK_SHIFT // remapped FDT address add x3, x2, #MAX_FDT_SIZE + SWAPPER_BLOCK_SIZE bic x4, x21, #SWAPPER_BLOCK_SIZE - 1 - mov x5, SWAPPER_RW_MMUFLAGS + mov_q x5, SWAPPER_RW_MMUFLAGS mov x6, #SWAPPER_BLOCK_SHIFT bl remap_region @@ -430,7 +430,7 @@ SYM_FUNC_START_LOCAL(create_kernel_mapping) adrp x3, _text // runtime __pa(_text) sub x6, x6, x3 // _end - _text add x6, x6, x5 // runtime __va(_end) - mov x7, SWAPPER_RW_MMUFLAGS + mov_q x7, SWAPPER_RW_MMUFLAGS map_memory x0, x1, x5, x6, x7, x3, (VA_BITS - PGDIR_SHIFT), x10, x11, x12, x13, x14 diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S index c2cb437821ca..9513a8d2ce0e 100644 --- a/arch/arm64/mm/proc.S +++ b/arch/arm64/mm/proc.S @@ -199,7 +199,7 @@ SYM_FUNC_END(idmap_cpu_replace_ttbr1) #ifdef CONFIG_UNMAP_KERNEL_AT_EL0 -#define KPTI_NG_PTE_FLAGS (PTE_ATTRINDX(MT_NORMAL) | SWAPPER_PTE_FLAGS) +#define KPTI_NG_PTE_FLAGS (PTE_ATTRINDX(MT_NORMAL) | SWAPPER_PTE_FLAGS | PTE_WRITE) .pushsection ".idmap.text", "a" @@ -290,7 +290,7 @@ SYM_TYPED_FUNC_START(idmap_kpti_install_ng_mappings) isb mov temp_pte, x5 - mov pte_flags, #KPTI_NG_PTE_FLAGS + mov_q pte_flags, KPTI_NG_PTE_FLAGS /* Everybody is enjoying the idmap, so we can rewrite swapper. */ /* PGD */ |