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@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-ssse3-asm.S | 15 +++++++-------- 1 file 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 -- 2.13.5
