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authorJosh Poimboeuf <jpoimboe@redhat.com>2017-09-18 14:42:08 -0500
committerHerbert Xu <herbert@gondor.apana.org.au>2017-09-20 17:42:36 +0800
commitd3dfbfe2e6e7ecd620531d5201314ad14c4ed5b3 (patch)
tree3ca1e7bf788cdc1a2c3f3b5e58e0cf7f4d99e1e2 /arch/x86
parent673ac6fbc74f835e2125df9ee39e8a2a423832e2 (diff)
crypto: x86/sha256-avx2 - Fix RBP usage
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@google.com> Reported-by: Peter Zijlstra <peterz@infradead.org> Tested-by: Eric Biggers <ebiggers@google.com> Acked-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/crypto/sha256-avx2-asm.S22
1 files 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)