Using RBP as a temporary register breaks frame pointer convention and breaks stack traces when unwinding from an interrupt in the crypto code. There's no need to use RBP as a temporary register for the TBL value, because it always stores the same value: the address of the K256 table. Instead just reference the address of K256 directly. Reported-by: Eric Biggers <ebiggers@xxxxxxxxxx> Reported-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Tested-by: Eric Biggers <ebiggers@xxxxxxxxxx> Acked-by: Eric Biggers <ebiggers@xxxxxxxxxx> Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> --- arch/x86/crypto/sha256-avx2-asm.S | 22 +++++++--------------- 1 file changed, 7 insertions(+), 15 deletions(-) diff --git a/arch/x86/crypto/sha256-avx2-asm.S b/arch/x86/crypto/sha256-avx2-asm.S index 89c8f09787d2..1420db15dcdd 100644 --- a/arch/x86/crypto/sha256-avx2-asm.S +++ b/arch/x86/crypto/sha256-avx2-asm.S @@ -98,8 +98,6 @@ d = %r8d e = %edx # clobbers NUM_BLKS y3 = %esi # clobbers INP - -TBL = %rbp SRND = CTX # SRND is same register as CTX a = %eax @@ -531,7 +529,6 @@ STACK_SIZE = _RSP + _RSP_SIZE ENTRY(sha256_transform_rorx) .align 32 pushq %rbx - pushq %rbp pushq %r12 pushq %r13 pushq %r14 @@ -568,8 +565,6 @@ ENTRY(sha256_transform_rorx) mov CTX, _CTX(%rsp) loop0: - lea K256(%rip), TBL - ## Load first 16 dwords from two blocks VMOVDQ 0*32(INP),XTMP0 VMOVDQ 1*32(INP),XTMP1 @@ -597,19 +592,19 @@ last_block_enter: .align 16 loop1: - vpaddd 0*32(TBL, SRND), X0, XFER + vpaddd K256+0*32(SRND), X0, XFER vmovdqa XFER, 0*32+_XFER(%rsp, SRND) FOUR_ROUNDS_AND_SCHED _XFER + 0*32 - vpaddd 1*32(TBL, SRND), X0, XFER + vpaddd K256+1*32(SRND), X0, XFER vmovdqa XFER, 1*32+_XFER(%rsp, SRND) FOUR_ROUNDS_AND_SCHED _XFER + 1*32 - vpaddd 2*32(TBL, SRND), X0, XFER + vpaddd K256+2*32(SRND), X0, XFER vmovdqa XFER, 2*32+_XFER(%rsp, SRND) FOUR_ROUNDS_AND_SCHED _XFER + 2*32 - vpaddd 3*32(TBL, SRND), X0, XFER + vpaddd K256+3*32(SRND), X0, XFER vmovdqa XFER, 3*32+_XFER(%rsp, SRND) FOUR_ROUNDS_AND_SCHED _XFER + 3*32 @@ -619,10 +614,11 @@ loop1: loop2: ## Do last 16 rounds with no scheduling - vpaddd 0*32(TBL, SRND), X0, XFER + vpaddd K256+0*32(SRND), X0, XFER vmovdqa XFER, 0*32+_XFER(%rsp, SRND) DO_4ROUNDS _XFER + 0*32 - vpaddd 1*32(TBL, SRND), X1, XFER + + vpaddd K256+1*32(SRND), X1, XFER vmovdqa XFER, 1*32+_XFER(%rsp, SRND) DO_4ROUNDS _XFER + 1*32 add $2*32, SRND @@ -676,9 +672,6 @@ loop3: ja done_hash do_last_block: - #### do last block - lea K256(%rip), TBL - VMOVDQ 0*16(INP),XWORD0 VMOVDQ 1*16(INP),XWORD1 VMOVDQ 2*16(INP),XWORD2 @@ -718,7 +711,6 @@ done_hash: popq %r14 popq %r13 popq %r12 - popq %rbp popq %rbx ret ENDPROC(sha256_transform_rorx) -- 2.13.5
