crypto: x86/sha1-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.

Use R11 instead of RBP.  Since R11 isn't a callee-saved register, it
doesn't need to be saved and restored on the stack.

Reported-by: Eric Biggers <[email protected]>
Reported-by: Peter Zijlstra <[email protected]>
Tested-by: Eric Biggers <[email protected]>
Acked-by: Eric Biggers <[email protected]>
Signed-off-by: Josh Poimboeuf <[email protected]>
Signed-off-by: Herbert Xu <[email protected]>

diff --git a/arch/x86/crypto/sha1_avx2_x86_64_asm.S b/arch/x86/crypto/sha1_avx2_x86_64_asm.S
index 1eab79c9ac484172a63d9cc0c4a409b7fffe7e8b..9f712a7dfd797cc499e1ef52ba7999078530494a 100644 (file)
--- a/arch/x86/crypto/sha1_avx2_x86_64_asm.S
+++ b/arch/x86/crypto/sha1_avx2_x86_64_asm.S
@@ -89,7 +89,7 @@
 #define        REG_RE  %rdx
 #define        REG_RTA %r12
 #define        REG_RTB %rbx
-#define        REG_T1  %ebp
+#define        REG_T1  %r11d
 #define        xmm_mov vmovups
 #define        avx2_zeroupper  vzeroupper
 #define        RND_F1  1
@@ -637,7 +637,6 @@ _loop3:
        ENTRY(\name)
 
        push    %rbx
-       push    %rbp
        push    %r12
        push    %r13
        push    %r14
@@ -673,7 +672,6 @@ _loop3:
        pop     %r14
        pop     %r13
        pop     %r12
-       pop     %rbp
        pop     %rbx
 
        ret