On Fri, Dec 29, 2017 at 10:47:06AM +0100, Mark Kettenis wrote:
> The Aarch32 assembly code in libcrypto assumes that armv7 supports
> unaligned access. It does, but only if you don't enable the bit that
> makes it trap on unaligned access. And we enable that bit on OpenBSD.
> So doing a SHA256 of an unaligned buffer (something ftp(1) ends up
> doing) you SIGBUS.
>
> This currently isn't an issue since our base GCC does not advertise
> that we're compiling for armv7 and up only. It barely knows about
> armv7 at all. But with clang that is no longer true. And we really
> want to build for armv7 and up only because that gives us proper
> atomic operations and such.
>
> So here is a diff that avoids the unaligned access bits that matter
> when compiling on OpenBSD.
>
> ok?
>
> P.S. Ports people might want to apply a similar diff to the OpenSSSL
> port if we still have it.
Any reason to not use __STRICT_ALIGNMENT for this?
>
>
> Index: lib/libcrypto/aes/asm/aes-armv4.pl
> ===================================================================
> RCS file: /cvs/src/lib/libcrypto/aes/asm/aes-armv4.pl,v
> retrieving revision 1.2
> diff -u -p -r1.2 aes-armv4.pl
> --- lib/libcrypto/aes/asm/aes-armv4.pl 9 Jul 2014 09:10:07 -0000
> 1.2
> +++ lib/libcrypto/aes/asm/aes-armv4.pl 29 Dec 2017 09:38:11 -0000
> @@ -172,7 +172,7 @@ AES_encrypt:
> mov $rounds,r0 @ inp
> mov $key,r2
> sub $tbl,r3,#AES_encrypt-AES_Te @ Te
> -#if __ARM_ARCH__<7
> +#if __ARM_ARCH__<7 || defined(__OpenBSD__)
> ldrb $s0,[$rounds,#3] @ load input data in endian-neutral
> ldrb $t1,[$rounds,#2] @ manner...
> ldrb $t2,[$rounds,#1]
> @@ -216,7 +216,7 @@ AES_encrypt:
> bl _armv4_AES_encrypt
>
> ldr $rounds,[sp],#4 @ pop out
> -#if __ARM_ARCH__>=7
> +#if __ARM_ARCH__>=7 && !defined(__OpenBSD__)
> #ifdef __ARMEL__
> rev $s0,$s0
> rev $s1,$s1
> @@ -432,7 +432,7 @@ _armv4_AES_set_encrypt_key:
> mov lr,r1 @ bits
> mov $key,r2 @ key
>
> -#if __ARM_ARCH__<7
> +#if __ARM_ARCH__<7 || defined(__OpenBSD__)
> ldrb $s0,[$rounds,#3] @ load input data in endian-neutral
> ldrb $t1,[$rounds,#2] @ manner...
> ldrb $t2,[$rounds,#1]
> @@ -517,7 +517,7 @@ _armv4_AES_set_encrypt_key:
> b .Ldone
>
> .Lnot128:
> -#if __ARM_ARCH__<7
> +#if __ARM_ARCH__<7 || defined(__OpenBSD__)
> ldrb $i2,[$rounds,#19]
> ldrb $t1,[$rounds,#18]
> ldrb $t2,[$rounds,#17]
> @@ -588,7 +588,7 @@ _armv4_AES_set_encrypt_key:
> b .L192_loop
>
> .Lnot192:
> -#if __ARM_ARCH__<7
> +#if __ARM_ARCH__<7 || defined(__OpenBSD__)
> ldrb $i2,[$rounds,#27]
> ldrb $t1,[$rounds,#26]
> ldrb $t2,[$rounds,#25]
> @@ -888,7 +888,7 @@ AES_decrypt:
> mov $rounds,r0 @ inp
> mov $key,r2
> sub $tbl,r3,#AES_decrypt-AES_Td @ Td
> -#if __ARM_ARCH__<7
> +#if __ARM_ARCH__<7 || defined(__OpenBSD__)
> ldrb $s0,[$rounds,#3] @ load input data in endian-neutral
> ldrb $t1,[$rounds,#2] @ manner...
> ldrb $t2,[$rounds,#1]
> @@ -932,7 +932,7 @@ AES_decrypt:
> bl _armv4_AES_decrypt
>
> ldr $rounds,[sp],#4 @ pop out
> -#if __ARM_ARCH__>=7
> +#if __ARM_ARCH__>=7 && !defined(__OpenBSD__)
> #ifdef __ARMEL__
> rev $s0,$s0
> rev $s1,$s1
> Index: lib/libcrypto/sha/asm/sha1-armv4-large.pl
> ===================================================================
> RCS file: /cvs/src/lib/libcrypto/sha/asm/sha1-armv4-large.pl,v
> retrieving revision 1.1.1.4
> diff -u -p -r1.1.1.4 sha1-armv4-large.pl
> --- lib/libcrypto/sha/asm/sha1-armv4-large.pl 13 Apr 2014 15:16:35 -0000
> 1.1.1.4
> +++ lib/libcrypto/sha/asm/sha1-armv4-large.pl 29 Dec 2017 09:38:11 -0000
> @@ -95,7 +95,7 @@ ___
> sub BODY_00_15 {
> my ($a,$b,$c,$d,$e)=@_;
> $code.=<<___;
> -#if __ARM_ARCH__<7
> +#if __ARM_ARCH__<7 || defined(__OpenBSD__)
> ldrb $t1,[$inp,#2]
> ldrb $t0,[$inp,#3]
> ldrb $t2,[$inp,#1]
> Index: lib/libcrypto/sha/asm/sha256-armv4.pl
> ===================================================================
> RCS file: /cvs/src/lib/libcrypto/sha/asm/sha256-armv4.pl,v
> retrieving revision 1.1.1.3
> diff -u -p -r1.1.1.3 sha256-armv4.pl
> --- lib/libcrypto/sha/asm/sha256-armv4.pl 13 Oct 2012 21:23:43 -0000
> 1.1.1.3
> +++ lib/libcrypto/sha/asm/sha256-armv4.pl 29 Dec 2017 09:38:11 -0000
> @@ -51,7 +51,7 @@ sub BODY_00_15 {
> my ($i,$a,$b,$c,$d,$e,$f,$g,$h) = @_;
>
> $code.=<<___ if ($i<16);
> -#if __ARM_ARCH__>=7
> +#if __ARM_ARCH__>=7 && !defined(__OpenBSD__)
> ldr $T1,[$inp],#4
> #else
> ldrb $T1,[$inp,#3] @ $i
> @@ -70,7 +70,7 @@ $code.=<<___;
> eor $t1,$f,$g
> #if $i>=16
> add $T1,$T1,$t3 @ from BODY_16_xx
> -#elif __ARM_ARCH__>=7 && defined(__ARMEL__)
> +#elif __ARM_ARCH__>=7 && defined(__ARMEL__) && !defined(__OpenBSD__)
> rev $T1,$T1
> #endif
> #if $i==15
> Index: lib/libcrypto/sha/asm/sha512-armv4.pl
> ===================================================================
> RCS file: /cvs/src/lib/libcrypto/sha/asm/sha512-armv4.pl,v
> retrieving revision 1.1.1.3
> diff -u -p -r1.1.1.3 sha512-armv4.pl
> --- lib/libcrypto/sha/asm/sha512-armv4.pl 13 Oct 2012 21:23:43 -0000
> 1.1.1.3
> +++ lib/libcrypto/sha/asm/sha512-armv4.pl 29 Dec 2017 09:38:11 -0000
> @@ -270,7 +270,7 @@ sha512_block_data_order:
> str $Thi,[sp,#$Foff+4]
>
> .L00_15:
> -#if __ARM_ARCH__<7
> +#if __ARM_ARCH__<7 || defined(__OpenBSD__)
> ldrb $Tlo,[$inp,#7]
> ldrb $t0, [$inp,#6]
> ldrb $t1, [$inp,#5]
>
