Patchwork crypto: arm/aes-cipher - move S-box to .rodata section

login
register
mail settings
Submitter Jinbum Park
Date Feb. 12, 2018, 1:52 p.m.
Message ID <20180212135237.GA3011@pjb1027-Latitude-E5410>
Download mbox | patch
Permalink /patch/10213051/
State Accepted
Delegated to: Herbert Xu
Headers show

Comments

Jinbum Park - Feb. 12, 2018, 1:52 p.m.
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@gmail.com>
---
 arch/arm/crypto/aes-cipher-core.S | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)
Ard Biesheuvel - Feb. 13, 2018, 10:57 a.m.
On 12 February 2018 at 13:52, Jinbum Park <jinb.park7@gmail.com> wrote:
> 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@gmail.com>

Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

> ---
>  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
>
Herbert Xu - Feb. 22, 2018, 3:11 p.m.
On Mon, Feb 12, 2018 at 10:52:37PM +0900, Jinbum Park wrote:
> 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@gmail.com>

Patch applied.  Thanks.

Patch

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)