x86/crypto/sha512-ssse3: Standardize stack alignment prologue

Use a more standard prologue for saving the stack pointer before
realigning the stack.

This enables ORC unwinding by allowing objtool to understand the stack
realignment.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Tested-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Sami Tolvanen <samitolvanen@google.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Link: https://lore.kernel.org/r/6ecaaac9f3828fbb903513bf90c34a08380a8e35.1614182415.git.jpoimboe@redhat.com

diff --git a/arch/x86/crypto/sha512-ssse3-asm.S b/arch/x86/crypto/sha512-ssse3-asm.S
index 50812af0b08350ec6f2d53e5b982101929e6e2e8..bd51c9070bedc32465b2464cfb88e26a5d78fde0 100644 (file)
--- a/arch/x86/crypto/sha512-ssse3-asm.S
+++ b/arch/x86/crypto/sha512-ssse3-asm.S
@@ -74,14 +74,10 @@ tmp0 =              %rax
 
 W_SIZE = 80*8
 WK_SIZE = 2*8
-RSPSAVE_SIZE = 1*8
-GPRSAVE_SIZE = 5*8
 
 frame_W = 0
 frame_WK = frame_W + W_SIZE
-frame_RSPSAVE = frame_WK + WK_SIZE
-frame_GPRSAVE = frame_RSPSAVE + RSPSAVE_SIZE
-frame_size = frame_GPRSAVE + GPRSAVE_SIZE
+frame_size = frame_WK + WK_SIZE
 
 # Useful QWORD "arrays" for simpler memory references
 # MSG, DIGEST, K_t, W_t are arrays
@@ -283,18 +279,18 @@ SYM_FUNC_START(sha512_transform_ssse3)
        test msglen, msglen
        je nowork
 
+       # Save GPRs
+       push    %rbx
+       push    %r12
+       push    %r13
+       push    %r14
+       push    %r15
+
        # Allocate Stack Space
-       mov     %rsp, %rax
+       push    %rbp
+       mov     %rsp, %rbp
        sub     $frame_size, %rsp
        and     $~(0x20 - 1), %rsp
-       mov     %rax, frame_RSPSAVE(%rsp)
-
-       # Save GPRs
-       mov     %rbx, frame_GPRSAVE(%rsp)
-       mov     %r12, frame_GPRSAVE +8*1(%rsp)
-       mov     %r13, frame_GPRSAVE +8*2(%rsp)
-       mov     %r14, frame_GPRSAVE +8*3(%rsp)
-       mov     %r15, frame_GPRSAVE +8*4(%rsp)
 
 updateblock:
 
@@ -355,15 +351,16 @@ updateblock:
        dec     msglen
        jnz     updateblock
 
-       # Restore GPRs
-       mov     frame_GPRSAVE(%rsp),      %rbx
-       mov     frame_GPRSAVE +8*1(%rsp), %r12
-       mov     frame_GPRSAVE +8*2(%rsp), %r13
-       mov     frame_GPRSAVE +8*3(%rsp), %r14
-       mov     frame_GPRSAVE +8*4(%rsp), %r15
-
        # Restore Stack Pointer
-       mov     frame_RSPSAVE(%rsp), %rsp
+       mov     %rbp, %rsp
+       pop     %rbp
+
+       # Restore GPRs
+       pop     %r15
+       pop     %r14
+       pop     %r13
+       pop     %r12
+       pop     %rbx
 
 nowork:
        ret