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authorJosh Poimboeuf <jpoimboe@redhat.com>2017-09-18 22:42:09 +0300
committerHerbert Xu <herbert@gondor.apana.org.au>2017-09-20 12:42:37 +0300
commit539012dcbdd1ff028268764385ed1f6d600812a7 (patch)
tree70af2b7c2bebc7b31f6a0535eac4585f5fec55de /arch
parentd3dfbfe2e6e7ecd620531d5201314ad14c4ed5b3 (diff)
downloadlinux-539012dcbdd1ff028268764385ed1f6d600812a7.tar.xz
crypto: x86/sha256-ssse3 - 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. 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>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/crypto/sha256-ssse3-asm.S15
1 files changed, 7 insertions, 8 deletions
diff --git a/arch/x86/crypto/sha256-ssse3-asm.S b/arch/x86/crypto/sha256-ssse3-asm.S
index 39b83c93e7fd..c6c05ed2c16a 100644
--- a/arch/x86/crypto/sha256-ssse3-asm.S
+++ b/arch/x86/crypto/sha256-ssse3-asm.S
@@ -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