[PATCH] crypto: arm/aes-cipher - move S-box to .rodata section

From: Jinbum Park
Date: Mon Feb 12 2018 - 08:52:53 EST


Move the AES inverse S-box to the .rodata section
where it is safe from abuse by speculation.

Signed-off-by: Jinbum Park <jinb.park7@xxxxxxxxx>
---
arch/arm/crypto/aes-cipher-core.S | 19 ++++++++++---------
1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/arch/arm/crypto/aes-cipher-core.S b/arch/arm/crypto/aes-cipher-core.S
index 54b3840..184d6c2 100644
--- a/arch/arm/crypto/aes-cipher-core.S
+++ b/arch/arm/crypto/aes-cipher-core.S
@@ -174,6 +174,16 @@
.ltorg
.endm

+ENTRY(__aes_arm_encrypt)
+ do_crypt fround, crypto_ft_tab, crypto_ft_tab + 1, 2
+ENDPROC(__aes_arm_encrypt)
+
+ .align 5
+ENTRY(__aes_arm_decrypt)
+ do_crypt iround, crypto_it_tab, __aes_arm_inverse_sbox, 0
+ENDPROC(__aes_arm_decrypt)
+
+ .section ".rodata", "a"
.align L1_CACHE_SHIFT
.type __aes_arm_inverse_sbox, %object
__aes_arm_inverse_sbox:
@@ -210,12 +220,3 @@ __aes_arm_inverse_sbox:
.byte 0x17, 0x2b, 0x04, 0x7e, 0xba, 0x77, 0xd6, 0x26
.byte 0xe1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0c, 0x7d
.size __aes_arm_inverse_sbox, . - __aes_arm_inverse_sbox
-
-ENTRY(__aes_arm_encrypt)
- do_crypt fround, crypto_ft_tab, crypto_ft_tab + 1, 2
-ENDPROC(__aes_arm_encrypt)
-
- .align 5
-ENTRY(__aes_arm_decrypt)
- do_crypt iround, crypto_it_tab, __aes_arm_inverse_sbox, 0
-ENDPROC(__aes_arm_decrypt)
--
1.9.1