[PATCH] crypto, x86: aesni: add compatibility with IAS

From: Jian Cai
Date: Mon Jun 22 2020 - 19:28:46 EST


Clang's integrated assembler complains "invalid reassignment of
non-absolute variable 'var_ddq_add'" while assembling
arch/x86/crypto/aes_ctrby8_avx-x86_64.S. It was because var_ddq_add was
reassigned with non-absolute values several times, which IAS did not
support. We can avoid the reassignment by replacing the uses of
var_ddq_add with its definitions accordingly to have compatilibility
with IAS.

Link: https://github.com/ClangBuiltLinux/linux/issues/1008
Reported-by: Sedat Dilek <sedat.dilek@xxxxxxxxx>
Reported-by: Fangrui Song <maskray@xxxxxxxxxx>
Tested-by: Sedat Dilek <sedat.dilek@xxxxxxxxx> # build+boot Linux v5.7.5; clang v11.0.0-git
Signed-off-by: Jian Cai <caij2003@xxxxxxxxx>
---
arch/x86/crypto/aes_ctrby8_avx-x86_64.S | 14 +++-----------
1 file changed, 3 insertions(+), 11 deletions(-)

diff --git a/arch/x86/crypto/aes_ctrby8_avx-x86_64.S b/arch/x86/crypto/aes_ctrby8_avx-x86_64.S
index ec437db1fa54..494a3bda8487 100644
--- a/arch/x86/crypto/aes_ctrby8_avx-x86_64.S
+++ b/arch/x86/crypto/aes_ctrby8_avx-x86_64.S
@@ -127,10 +127,6 @@ ddq_add_8:

/* generate a unique variable for ddq_add_x */

-.macro setddq n
- var_ddq_add = ddq_add_\n
-.endm
-
/* generate a unique variable for xmm register */
.macro setxdata n
var_xdata = %xmm\n
@@ -140,9 +136,7 @@ ddq_add_8:

.macro club name, id
.altmacro
- .if \name == DDQ_DATA
- setddq %\id
- .elseif \name == XDATA
+ .if \name == XDATA
setxdata %\id
.endif
.noaltmacro
@@ -165,9 +159,8 @@ ddq_add_8:

.set i, 1
.rept (by - 1)
- club DDQ_DATA, i
club XDATA, i
- vpaddq var_ddq_add(%rip), xcounter, var_xdata
+ vpaddq (ddq_add_1 + 16 * (i - 1))(%rip), xcounter, var_xdata
vptest ddq_low_msk(%rip), var_xdata
jnz 1f
vpaddq ddq_high_add_1(%rip), var_xdata, var_xdata
@@ -180,8 +173,7 @@ ddq_add_8:
vmovdqa 1*16(p_keys), xkeyA

vpxor xkey0, xdata0, xdata0
- club DDQ_DATA, by
- vpaddq var_ddq_add(%rip), xcounter, xcounter
+ vpaddq (ddq_add_1 + 16 * (by - 1))(%rip), xcounter, xcounter
vptest ddq_low_msk(%rip), xcounter
jnz 1f
vpaddq ddq_high_add_1(%rip), xcounter, xcounter
--
2.27.0.111.gc72c7da667-goog