[PATCH v2 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 <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/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