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authorJoey Gouly <joey.gouly@arm.com>2023-06-06 16:58:50 +0200
committerCatalin Marinas <catalin.marinas@arm.com>2023-06-06 17:52:41 +0200
commitf0af339fc408a55c9f48f5d9ca47059ef1eb36b8 (patch)
treef71ee516598e602503bfcfea30789697cfdbcbca /arch/arm64
parentKVM: arm64: expose ID_AA64MMFR3_EL1 to guests (diff)
downloadlinux-f0af339fc408a55c9f48f5d9ca47059ef1eb36b8.tar.xz
linux-f0af339fc408a55c9f48f5d9ca47059ef1eb36b8.zip
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>
Diffstat (limited to 'arch/arm64')
-rw-r--r--arch/arm64/include/asm/kernel-pgtable.h8
-rw-r--r--arch/arm64/kernel/head.S8
-rw-r--r--arch/arm64/mm/proc.S4
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 */