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authorCatalin Marinas <catalin.marinas@arm.com>2022-03-03 18:00:44 +0000
committerCatalin Marinas <catalin.marinas@arm.com>2022-03-08 10:03:51 +0000
commit6e2edd6371a497a6350bb735534c9bda2a31f43d (patch)
tree2c7c0ebd1e48ea7301b9674b0d75f7ced5acafe2 /arch/arm64/include
parent4f6de676d94ee8ddfc2e7e7cd935fc7cb2feff3a (diff)
arm64: Ensure execute-only permissions are not allowed without EPAN
Commit 18107f8a2df6 ("arm64: Support execute-only permissions with Enhanced PAN") re-introduced execute-only permissions when EPAN is available. When EPAN is not available, arch_filter_pgprot() is supposed to change a PAGE_EXECONLY permission into PAGE_READONLY_EXEC. However, if BTI or MTE are present, such check does not detect the execute-only pgprot in the presence of PTE_GP (BTI) or MT_NORMAL_TAGGED (MTE), allowing the user to request PROT_EXEC with PROT_BTI or PROT_MTE. Remove the arch_filter_pgprot() function, change the default VM_EXEC permissions to PAGE_READONLY_EXEC and update the protection_map[] array at core_initcall() if EPAN is detected. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Fixes: 18107f8a2df6 ("arm64: Support execute-only permissions with Enhanced PAN") Cc: <stable@vger.kernel.org> # 5.13.x Acked-by: Will Deacon <will@kernel.org> Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com> Tested-by: Vladimir Murzin <vladimir.murzin@arm.com>
Diffstat (limited to 'arch/arm64/include')
-rw-r--r--arch/arm64/include/asm/pgtable-prot.h4
-rw-r--r--arch/arm64/include/asm/pgtable.h11
2 files changed, 2 insertions, 13 deletions
diff --git a/arch/arm64/include/asm/pgtable-prot.h b/arch/arm64/include/asm/pgtable-prot.h
index 7032f04c8ac6..b1e1b74d993c 100644
--- a/arch/arm64/include/asm/pgtable-prot.h
+++ b/arch/arm64/include/asm/pgtable-prot.h
@@ -92,7 +92,7 @@ extern bool arm64_use_ng_mappings;
#define __P001 PAGE_READONLY
#define __P010 PAGE_READONLY
#define __P011 PAGE_READONLY
-#define __P100 PAGE_EXECONLY
+#define __P100 PAGE_READONLY_EXEC /* PAGE_EXECONLY if Enhanced PAN */
#define __P101 PAGE_READONLY_EXEC
#define __P110 PAGE_READONLY_EXEC
#define __P111 PAGE_READONLY_EXEC
@@ -101,7 +101,7 @@ extern bool arm64_use_ng_mappings;
#define __S001 PAGE_READONLY
#define __S010 PAGE_SHARED
#define __S011 PAGE_SHARED
-#define __S100 PAGE_EXECONLY
+#define __S100 PAGE_READONLY_EXEC /* PAGE_EXECONLY if Enhanced PAN */
#define __S101 PAGE_READONLY_EXEC
#define __S110 PAGE_SHARED_EXEC
#define __S111 PAGE_SHARED_EXEC
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index c4ba047a82d2..94e147e5456c 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -1017,17 +1017,6 @@ static inline bool arch_wants_old_prefaulted_pte(void)
}
#define arch_wants_old_prefaulted_pte arch_wants_old_prefaulted_pte
-static inline pgprot_t arch_filter_pgprot(pgprot_t prot)
-{
- if (cpus_have_const_cap(ARM64_HAS_EPAN))
- return prot;
-
- if (pgprot_val(prot) != pgprot_val(PAGE_EXECONLY))
- return prot;
-
- return PAGE_READONLY_EXEC;
-}
-
static inline bool pud_sect_supported(void)
{
return PAGE_SIZE == SZ_4K;