[Buildroot] [PATCH 1/1] package/libnss: fix build on ARM big endian

[Giulio Benetti]

Hi Fabrice,

On 8/7/21 11:32 PM, Fabrice Fontaine wrote:
> Fix the follownig build failure on ARM big endian raised since bump to
> version 3.68 in commit 0a73b9b962421ce7a72c88e5f5bbd8849f21b041:
> 
> Linux2.6_aarch64_aarch64_be-linux-gnu-gcc_glibc_PTH_64_DBG.OBJ/Linux_SINGLE_SHLIB/sha256-armv8.o: In function `SHA256_Compress_Native':
> sha256-armv8.c:(.text.SHA256_Compress_Native+0x0): multiple definition of `SHA256_Compress_Native'
> Linux2.6_aarch64_aarch64_be-linux-gnu-gcc_glibc_PTH_64_DBG.OBJ/Linux_SINGLE_SHLIB/sha512.o:sha512.c:(.text.SHA256_Compress_Native+0x0): first defined here
> Linux2.6_aarch64_aarch64_be-linux-gnu-gcc_glibc_PTH_64_DBG.OBJ/Linux_SINGLE_SHLIB/sha256-armv8.o: In function `SHA256_Update_Native':
> sha256-armv8.c:(.text.SHA256_Update_Native+0x0): multiple definition of `SHA256_Update_Native'
> Linux2.6_aarch64_aarch64_be-linux-gnu-gcc_glibc_PTH_64_DBG.OBJ/Linux_SINGLE_SHLIB/sha512.o:sha512.c:(.text.SHA256_Update_Native+0x0): first defined here
> 
> Fixes:
>   - http://autobuild.buildroot.org/results/237aba0c16a34fec1b0fe50fe08cace438eda1bf
> 
> Signed-off-by: Fabrice Fontaine <fontaine.fabrice at gmail.com>
> ---
>   ...2.c-fix-SHA256-redefinition-on-ARM-b.patch | 47 +++++++++++++++++++
>   1 file changed, 47 insertions(+)
>   create mode 100644 package/libnss/0001-lib-freebl-sha512.c-fix-SHA256-redefinition-on-ARM-b.patch
> 
> diff --git a/package/libnss/0001-lib-freebl-sha512.c-fix-SHA256-redefinition-on-ARM-b.patch b/package/libnss/0001-lib-freebl-sha512.c-fix-SHA256-redefinition-on-ARM-b.patch
> new file mode 100644
> index 0000000000..f925f20051
> --- /dev/null
> +++ b/package/libnss/0001-lib-freebl-sha512.c-fix-SHA256-redefinition-on-ARM-b.patch
> @@ -0,0 +1,47 @@
> +From 434d79c52db5b680accc531572319bd7094fa470 Mon Sep 17 00:00:00 2001
> +From: Fabrice Fontaine <fontaine.fabrice at gmail.com>
> +Date: Sat, 7 Aug 2021 23:19:01 +0200
> +Subject: [PATCH] lib/freebl/sha512.c: fix SHA256 redefinition on ARM big
> + endian
> +
> +For an unknown reason, SHA256_{Compress,Update}_Native are defined in
> +lib/freebl/sha512.c if IS_LITTLE_ENDIAN is undefined since version 3.68
> +and
> +https://github.com/nss-dev/nss/commit/e1e00f21f2d73e0d5d27651ad5606efa5714abe4
> +
> +This raises the following build failure on ARM big endian:
> +
> +Linux2.6_aarch64_aarch64_be-linux-gnu-gcc_glibc_PTH_64_DBG.OBJ/Linux_SINGLE_SHLIB/sha256-armv8.o: In function `SHA256_Compress_Native':
> +sha256-armv8.c:(.text.SHA256_Compress_Native+0x0): multiple definition of `SHA256_Compress_Native'
> +Linux2.6_aarch64_aarch64_be-linux-gnu-gcc_glibc_PTH_64_DBG.OBJ/Linux_SINGLE_SHLIB/sha512.o:sha512.c:(.text.SHA256_Compress_Native+0x0): first defined here
> +Linux2.6_aarch64_aarch64_be-linux-gnu-gcc_glibc_PTH_64_DBG.OBJ/Linux_SINGLE_SHLIB/sha256-armv8.o: In function `SHA256_Update_Native':
> +sha256-armv8.c:(.text.SHA256_Update_Native+0x0): multiple definition of `SHA256_Update_Native'
> +Linux2.6_aarch64_aarch64_be-linux-gnu-gcc_glibc_PTH_64_DBG.OBJ/Linux_SINGLE_SHLIB/sha512.o:sha512.c:(.text.SHA256_Update_Native+0x0): first defined here
> +
> +Revert this change as it seems completely unrelated to the commit title
> +"Bug 1655493 - Support SHA2 HW acceleration using Intel SHA Extension"

I'm not completely sure about this, since I remember most of armv8 
accelerations only work for LITTLE_ENDIAN. But I can't login to the 
Mozilla Bugzilla because of two factor authentication I've never enabled 
and I've asked help to fix this days ago with no answer. Do you have 
access to it?

Can you please clarify if that acceleration is valid on BIG_ENDIAN too?
It's not written anywhere, but more than one lib/freebl/ lib 
acceleration has been done only for LITTLE_ENDIAN. What worries me is 
the hash table at the top that *maybe* is only suitable for LITTLE_ENDIAN:
https://hg.mozilla.org/projects/nss/file/tip/lib/freebl/sha256-armv8.c#l24

For example check this patch I've sent time ago:
https://hg.mozilla.org/projects/nss/rev/fa0d958de0c3cf99a7ec66e819b128c7bc88ff9f
and the related bug:
https://bugzilla.mozilla.org/show_bug.cgi?id=1580126

That makes me believe that is only LITTLE_ENDIAN compatible also due to 
this:
https://hg.mozilla.org/projects/nss/file/tip/lib/freebl/sha512.c#l167

BUT I can't reach anyone, and they don't sign off the commits, so no 
e-mail to CC. Maybe you can through Mozilla Bugzilla?

Thanks in advance
Best regards
-- 
Giulio Benetti
Benetti Engineering sas

> +Fixes:
> + - http://autobuild.buildroot.org/results/237aba0c16a34fec1b0fe50fe08cace438eda1bf
> +
> +Signed-off-by: Fabrice Fontaine <fontaine.fabrice at gmail.com>
> +---
> + nss/lib/freebl/sha512.c | 2 +-
> + 1 file changed, 1 insertion(+), 1 deletion(-)
> +
> +diff --git a/nss/lib/freebl/sha512.c b/nss/lib/freebl/sha512.c
> +index 946ab9f7f..3ec414b52 100644
> +--- a/nss/lib/freebl/sha512.c
> ++++ b/nss/lib/freebl/sha512.c
> +@@ -164,7 +164,7 @@ static void SHA256_Compress_Generic(SHA256Context *ctx);
> + static void SHA256_Update_Generic(SHA256Context *ctx, const unsigned char *input,
> +                                   unsigned int inputLen);
> +
> +-#if !defined(USE_HW_SHA2) || !defined(IS_LITTLE_ENDIAN)
> ++#if !defined(USE_HW_SHA2)
> + void
> + SHA256_Compress_Native(SHA256Context *ctx)
> + {
> +--
> +2.30.2
> +
>