Using RBP as a temporary register breaks frame pointer convention and breaks stack traces when unwinding from an interrupt in the crypto code. Mix things up a little bit to get rid of the RBP usage, without hurting performance too much. Use RDI instead of RBP for the TBL pointer. That will clobber CTX, so spill CTX onto the stack and use R12 to read it in the outer loop. R12 is used as a non-persistent temporary variable elsewhere, so it's safe to use. Also remove the unused y4 variable. Reported-by: Eric Biggers <ebiggers3@xxxxxxxxx> 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/sha512-avx2-asm.S | 75 ++++++++++++++++++++------------------- 1 file changed, 39 insertions(+), 36 deletions(-) diff --git a/arch/x86/crypto/sha512-avx2-asm.S b/arch/x86/crypto/sha512-avx2-asm.S index 7f5f6c6ec72e..b16d56005162 100644 --- a/arch/x86/crypto/sha512-avx2-asm.S +++ b/arch/x86/crypto/sha512-avx2-asm.S @@ -69,8 +69,9 @@ XFER = YTMP0 BYTE_FLIP_MASK = %ymm9 -# 1st arg -CTX = %rdi +# 1st arg is %rdi, which is saved to the stack and accessed later via %r12 +CTX1 = %rdi +CTX2 = %r12 # 2nd arg INP = %rsi # 3rd arg @@ -81,7 +82,7 @@ d = %r8 e = %rdx y3 = %rsi -TBL = %rbp +TBL = %rdi # clobbers CTX1 a = %rax b = %rbx @@ -91,26 +92,26 @@ g = %r10 h = %r11 old_h = %r11 -T1 = %r12 +T1 = %r12 # clobbers CTX2 y0 = %r13 y1 = %r14 y2 = %r15 -y4 = %r12 - # Local variables (stack frame) XFER_SIZE = 4*8 SRND_SIZE = 1*8 INP_SIZE = 1*8 INPEND_SIZE = 1*8 +CTX_SIZE = 1*8 RSPSAVE_SIZE = 1*8 -GPRSAVE_SIZE = 6*8 +GPRSAVE_SIZE = 5*8 frame_XFER = 0 frame_SRND = frame_XFER + XFER_SIZE frame_INP = frame_SRND + SRND_SIZE frame_INPEND = frame_INP + INP_SIZE -frame_RSPSAVE = frame_INPEND + INPEND_SIZE +frame_CTX = frame_INPEND + INPEND_SIZE +frame_RSPSAVE = frame_CTX + CTX_SIZE frame_GPRSAVE = frame_RSPSAVE + RSPSAVE_SIZE frame_size = frame_GPRSAVE + GPRSAVE_SIZE @@ -576,12 +577,11 @@ ENTRY(sha512_transform_rorx) mov %rax, frame_RSPSAVE(%rsp) # Save GPRs - mov %rbp, frame_GPRSAVE(%rsp) - mov %rbx, 8*1+frame_GPRSAVE(%rsp) - mov %r12, 8*2+frame_GPRSAVE(%rsp) - mov %r13, 8*3+frame_GPRSAVE(%rsp) - mov %r14, 8*4+frame_GPRSAVE(%rsp) - mov %r15, 8*5+frame_GPRSAVE(%rsp) + mov %rbx, 8*0+frame_GPRSAVE(%rsp) + mov %r12, 8*1+frame_GPRSAVE(%rsp) + mov %r13, 8*2+frame_GPRSAVE(%rsp) + mov %r14, 8*3+frame_GPRSAVE(%rsp) + mov %r15, 8*4+frame_GPRSAVE(%rsp) shl $7, NUM_BLKS # convert to bytes jz done_hash @@ -589,14 +589,17 @@ ENTRY(sha512_transform_rorx) mov NUM_BLKS, frame_INPEND(%rsp) ## load initial digest - mov 8*0(CTX),a - mov 8*1(CTX),b - mov 8*2(CTX),c - mov 8*3(CTX),d - mov 8*4(CTX),e - mov 8*5(CTX),f - mov 8*6(CTX),g - mov 8*7(CTX),h + mov 8*0(CTX1), a + mov 8*1(CTX1), b + mov 8*2(CTX1), c + mov 8*3(CTX1), d + mov 8*4(CTX1), e + mov 8*5(CTX1), f + mov 8*6(CTX1), g + mov 8*7(CTX1), h + + # save %rdi (CTX) before it gets clobbered + mov %rdi, frame_CTX(%rsp) vmovdqa PSHUFFLE_BYTE_FLIP_MASK(%rip), BYTE_FLIP_MASK @@ -652,14 +655,15 @@ loop2: subq $1, frame_SRND(%rsp) jne loop2 - addm 8*0(CTX),a - addm 8*1(CTX),b - addm 8*2(CTX),c - addm 8*3(CTX),d - addm 8*4(CTX),e - addm 8*5(CTX),f - addm 8*6(CTX),g - addm 8*7(CTX),h + mov frame_CTX(%rsp), CTX2 + addm 8*0(CTX2), a + addm 8*1(CTX2), b + addm 8*2(CTX2), c + addm 8*3(CTX2), d + addm 8*4(CTX2), e + addm 8*5(CTX2), f + addm 8*6(CTX2), g + addm 8*7(CTX2), h mov frame_INP(%rsp), INP add $128, INP @@ -669,12 +673,11 @@ loop2: done_hash: # Restore GPRs - mov frame_GPRSAVE(%rsp) ,%rbp - mov 8*1+frame_GPRSAVE(%rsp) ,%rbx - mov 8*2+frame_GPRSAVE(%rsp) ,%r12 - mov 8*3+frame_GPRSAVE(%rsp) ,%r13 - mov 8*4+frame_GPRSAVE(%rsp) ,%r14 - mov 8*5+frame_GPRSAVE(%rsp) ,%r15 + mov 8*0+frame_GPRSAVE(%rsp), %rbx + mov 8*1+frame_GPRSAVE(%rsp), %r12 + mov 8*2+frame_GPRSAVE(%rsp), %r13 + mov 8*3+frame_GPRSAVE(%rsp), %r14 + mov 8*4+frame_GPRSAVE(%rsp), %r15 # Restore Stack Pointer mov frame_RSPSAVE(%rsp), %rsp -- 2.13.5
