From f68fa9a7de96d486acb7f503e6a34c68ae8569c9 Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Tue, 14 Dec 2021 15:27:12 +0000 Subject: [PATCH] arm64: Add macro version of the BTI instruction BTI is only available from v8.5 so we need to encode it using HINT in generic code and for older toolchains. Add an assembler macro based on one written by Mark Rutland which lets us use the mnemonic and update the existing users. Suggested-by: Mark Rutland Acked-by: Ard Biesheuvel Acked-by: Will Deacon Signed-off-by: Mark Brown Acked-by: Mark Rutland Link: https://lore.kernel.org/r/20211214152714.2380849-2-broonie@kernel.org Signed-off-by: Catalin Marinas --- arch/arm64/crypto/aes-modes.S | 10 +++++----- arch/arm64/include/asm/assembler.h | 10 ++++++++++ arch/arm64/include/asm/linkage.h | 7 +------ 3 files changed, 16 insertions(+), 11 deletions(-) diff --git a/arch/arm64/crypto/aes-modes.S b/arch/arm64/crypto/aes-modes.S index b495de22bb380..ff01f0167ba2c 100644 --- a/arch/arm64/crypto/aes-modes.S +++ b/arch/arm64/crypto/aes-modes.S @@ -363,15 +363,15 @@ ST5( mov v4.16b, vctr.16b ) adr x16, 1f sub x16, x16, x12, lsl #3 br x16 - hint 34 // bti c + bti c mov v0.d[0], vctr.d[0] - hint 34 // bti c + bti c mov v1.d[0], vctr.d[0] - hint 34 // bti c + bti c mov v2.d[0], vctr.d[0] - hint 34 // bti c + bti c mov v3.d[0], vctr.d[0] -ST5( hint 34 ) +ST5( bti c ) ST5( mov v4.d[0], vctr.d[0] ) 1: b 2f .previous diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h index 136d13f3d6e92..e8bd0af0141c3 100644 --- a/arch/arm64/include/asm/assembler.h +++ b/arch/arm64/include/asm/assembler.h @@ -790,6 +790,16 @@ alternative_endif .Lnoyield_\@: .endm +/* + * Branch Target Identifier (BTI) + */ + .macro bti, targets + .equ .L__bti_targets_c, 34 + .equ .L__bti_targets_j, 36 + .equ .L__bti_targets_jc,38 + hint #.L__bti_targets_\targets + .endm + /* * This macro emits a program property note section identifying * architecture features which require special handling, mainly for diff --git a/arch/arm64/include/asm/linkage.h b/arch/arm64/include/asm/linkage.h index 9906541a68619..c5d0c11d7709b 100644 --- a/arch/arm64/include/asm/linkage.h +++ b/arch/arm64/include/asm/linkage.h @@ -6,12 +6,7 @@ #if defined(CONFIG_ARM64_BTI_KERNEL) && defined(__aarch64__) -/* - * Since current versions of gas reject the BTI instruction unless we - * set the architecture version to v8.5 we use the hint instruction - * instead. - */ -#define BTI_C hint 34 ; +#define BTI_C bti c ; /* * When using in-kernel BTI we need to ensure that PCS-conformant assembly -- 2.39.5