From c24e4addacca66cb2269a3c8c8419cbcab94268c Mon Sep 17 00:00:00 2001 From: Andrew Turner Date: Mon, 2 Oct 2023 14:05:58 +0100 Subject: [PATCH] Add BTI landing pads to the AArch64 SHA2 assembly The Arm Branch Target Identification (BTI) extension guards against branching to an unintended instruction. To support BTI add the landing pad instructions to the SHA2 functions. These are from the hint space so are a nop on hardware that lacks BTI support or if BTI isn't enabled. Signed-off-by: Andrew Turner --- module/icp/asm-aarch64/sha2/sha256-armv8.S | 3 +++ module/icp/asm-aarch64/sha2/sha512-armv8.S | 2 ++ 2 files changed, 5 insertions(+) diff --git a/module/icp/asm-aarch64/sha2/sha256-armv8.S b/module/icp/asm-aarch64/sha2/sha256-armv8.S index fa50c4e74d59..7ae486e4e229 100644 --- a/module/icp/asm-aarch64/sha2/sha256-armv8.S +++ b/module/icp/asm-aarch64/sha2/sha256-armv8.S @@ -49,6 +49,7 @@ .type zfs_sha256_block_armv7,%function .align 6 zfs_sha256_block_armv7: + hint #34 // bti c stp x29,x30,[sp,#-128]! add x29,sp,#0 @@ -1015,6 +1016,7 @@ zfs_sha256_block_armv7: .type zfs_sha256_block_armv8,%function .align 6 zfs_sha256_block_armv8: + hint #34 // bti c .Lv8_entry: stp x29,x30,[sp,#-16]! add x29,sp,#0 @@ -1155,6 +1157,7 @@ zfs_sha256_block_armv8: .type zfs_sha256_block_neon,%function .align 4 zfs_sha256_block_neon: + hint #34 // bti c .Lneon_entry: stp x29, x30, [sp, #-16]! mov x29, sp diff --git a/module/icp/asm-aarch64/sha2/sha512-armv8.S b/module/icp/asm-aarch64/sha2/sha512-armv8.S index 1683fc1ca53c..9c61eeee4d7b 100644 --- a/module/icp/asm-aarch64/sha2/sha512-armv8.S +++ b/module/icp/asm-aarch64/sha2/sha512-armv8.S @@ -73,6 +73,7 @@ .type zfs_sha512_block_armv7,%function .align 6 zfs_sha512_block_armv7: + hint #34 // bti c stp x29,x30,[sp,#-128]! add x29,sp,#0 @@ -1040,6 +1041,7 @@ zfs_sha512_block_armv7: .type zfs_sha512_block_armv8,%function .align 6 zfs_sha512_block_armv8: + hint #34 // bti c .Lv8_entry: // Armv8.3-A PAuth: even though x30 is pushed to stack it is not popped later stp x29,x30,[sp,#-16]!