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crypto: x86/sha256-ssse3 - Fix RBP usage

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Using RBP as a temporary register breaks frame pointer convention and
breaks stack traces when unwinding from an interrupt in the crypto code.

Swap the usages of R12 and RBP.  Use R12 for the TBL register, and use
RBP to store the pre-aligned stack pointer.

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>
This commit is contained in:
Josh Poimboeuf 2017-09-18 14:42:09 -05:00 committed by Herbert Xu
parent d3dfbfe2e6
commit 539012dcbd
1 changed files with 7 additions and 8 deletions
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15
arch/x86/crypto/sha256-ssse3-asm.S
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@ -95,7 +95,7 @@ SRND = %rsi # clobbers INP
c = %ecx
d = %r8d
e = %edx
TBL = %rbp
TBL = %r12
a = %eax
b = %ebx
@ -356,13 +356,13 @@ a = TMP_
ENTRY(sha256_transform_ssse3)
.align 32
pushq %rbx
pushq %rbp
pushq %r12
pushq %r13
pushq %r14
pushq %r15
pushq %r12
pushq %rbp
mov %rsp, %rbp
mov %rsp, %r12
subq $STACK_SIZE, %rsp
and $~15, %rsp
@ -462,13 +462,12 @@ loop2:
done_hash:
mov %r12, %rsp
popq %r12
mov %rbp, %rsp
popq %rbp
popq %r15
popq %r14
popq %r13
popq %rbp
popq %r12
popq %rbx
ret