[PATCH 02/12] x86/crypto: Fix RBP usage in camellia-x86_64-asm_64.S

[Josh Poimboeuf]

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

Use R12 instead of RBP.  Both are callee-saved registers, so the
substitution is straightforward.

Reported-by: Eric Biggers <ebigg...@google.com>
Reported-by: Peter Zijlstra <pet...@infradead.org>
Signed-off-by: Josh Poimboeuf <jpoim...@redhat.com>
---
 arch/x86/crypto/camellia-x86_64-asm_64.S | 26 +++++++++++++-------------
 1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/arch/x86/crypto/camellia-x86_64-asm_64.S 
b/arch/x86/crypto/camellia-x86_64-asm_64.S
index 310319c601ed..95ba6956a7f6 100644
--- a/arch/x86/crypto/camellia-x86_64-asm_64.S
+++ b/arch/x86/crypto/camellia-x86_64-asm_64.S
@@ -75,17 +75,17 @@
 #define RCD1bh %dh
 
 #define RT0 %rsi
-#define RT1 %rbp
+#define RT1 %r12
 #define RT2 %r8
 
 #define RT0d %esi
-#define RT1d %ebp
+#define RT1d %r12d
 #define RT2d %r8d
 
 #define RT2bl %r8b
 
 #define RXOR %r9
-#define RRBP %r10
+#define RR12 %r10
 #define RDST %r11
 
 #define RXORd %r9d
@@ -197,7 +197,7 @@ ENTRY(__camellia_enc_blk)
         *      %rdx: src
         *      %rcx: bool xor
         */
-       movq %rbp, RRBP;
+       movq %r12, RR12;
 
        movq %rcx, RXOR;
        movq %rsi, RDST;
@@ -227,13 +227,13 @@ ENTRY(__camellia_enc_blk)
 
        enc_outunpack(mov, RT1);
 
-       movq RRBP, %rbp;
+       movq RR12, %r12;
        ret;
 
 .L__enc_xor:
        enc_outunpack(xor, RT1);
 
-       movq RRBP, %rbp;
+       movq RR12, %r12;
        ret;
 ENDPROC(__camellia_enc_blk)
 
@@ -248,7 +248,7 @@ ENTRY(camellia_dec_blk)
        movl $24, RXORd;
        cmovel RXORd, RT2d; /* max */
 
-       movq %rbp, RRBP;
+       movq %r12, RR12;
        movq %rsi, RDST;
        movq %rdx, RIO;
 
@@ -271,7 +271,7 @@ ENTRY(camellia_dec_blk)
 
        dec_outunpack();
 
-       movq RRBP, %rbp;
+       movq RR12, %r12;
        ret;
 ENDPROC(camellia_dec_blk)
 
@@ -433,7 +433,7 @@ ENTRY(__camellia_enc_blk_2way)
         */
        pushq %rbx;
 
-       movq %rbp, RRBP;
+       movq %r12, RR12;
        movq %rcx, RXOR;
        movq %rsi, RDST;
        movq %rdx, RIO;
@@ -461,14 +461,14 @@ ENTRY(__camellia_enc_blk_2way)
 
        enc_outunpack2(mov, RT2);
 
-       movq RRBP, %rbp;
+       movq RR12, %r12;
        popq %rbx;
        ret;
 
 .L__enc2_xor:
        enc_outunpack2(xor, RT2);
 
-       movq RRBP, %rbp;
+       movq RR12, %r12;
        popq %rbx;
        ret;
 ENDPROC(__camellia_enc_blk_2way)
@@ -485,7 +485,7 @@ ENTRY(camellia_dec_blk_2way)
        cmovel RXORd, RT2d; /* max */
 
        movq %rbx, RXOR;
-       movq %rbp, RRBP;
+       movq %r12, RR12;
        movq %rsi, RDST;
        movq %rdx, RIO;
 
@@ -508,7 +508,7 @@ ENTRY(camellia_dec_blk_2way)
 
        dec_outunpack2();
 
-       movq RRBP, %rbp;
+       movq RR12, %r12;
        movq RXOR, %rbx;
        ret;
 ENDPROC(camellia_dec_blk_2way)
-- 
2.13.5