[Buildroot] [PATCH 1/4] package/libnss: fix build failure with ARM without NEON extension

[Giulio Benetti <giulio.benetti@benettiengineering.com>]

Hi Arnout,

On 10/23/19 11:44 PM, Arnout Vandecappelle wrote:
> 
> 
> On 23/10/2019 12:23, Giulio Benetti wrote:
>> At the moment libnss assumes that every ARM has NEON extension but it's
>> not that way. So add a patch to make it aware of it and use native
>> functions in place of NEON optimized ones.
>>
>> Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
> 
>   You forgot:
> 
> Fixes:
> http://autobuild.buildroot.net/results/1342d305d1aeebef7af54a83afc094fda12421e2

Oops, yes.

>> ---
>> Already sent upstream:
>> https://bugzilla.mozilla.org/show_bug.cgi?id=1590676
>> ---
>>   ...ix-build-if-arm-doesn-t-support-NEON.patch | 47 +++++++++++++++++++
>>   1 file changed, 47 insertions(+)
>>   create mode 100644 package/libnss/0003-Bug-1590676-Fix-build-if-arm-doesn-t-support-NEON.patch
>>
>> diff --git a/package/libnss/0003-Bug-1590676-Fix-build-if-arm-doesn-t-support-NEON.patch b/package/libnss/0003-Bug-1590676-Fix-build-if-arm-doesn-t-support-NEON.patch
>> new file mode 100644
>> index 0000000000..e536282371
>> --- /dev/null
>> +++ b/package/libnss/0003-Bug-1590676-Fix-build-if-arm-doesn-t-support-NEON.patch
>> @@ -0,0 +1,47 @@
>> +From 946bc2864b0de7b63a4ec415e42e622d591a8753 Mon Sep 17 00:00:00 2001
>> +From: Giulio Benetti <giulio.benetti@benettiengineering.com>
>> +Date: Wed, 23 Oct 2019 11:47:03 +0200
>> +Subject: [PATCH] Bug 1590676 - Fix build if arm doesn't support NEON
>> +
>> +At the moment NSS assumes that ARM supports NEON extension but this is
>> +not true and leads to build failure on ARM without NEON extension.
>> +Add check to assure USE_HW_AES is not defined if ARM without NEON
>> +extension is used.
>> +
>> +Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
>> +---
>> + nss/lib/freebl/aes-armv8.c | 3 ++-
>> + nss/lib/freebl/rijndael.c  | 3 ++-
>> + 2 files changed, 4 insertions(+), 2 deletions(-)
>> +
>> +diff --git a/nss/lib/freebl/aes-armv8.c b/nss/lib/freebl/aes-armv8.c
>> +index 40d5e2d34..a5df53891 100644
>> +--- a/nss/lib/freebl/aes-armv8.c
>> ++++ b/nss/lib/freebl/aes-armv8.c
> 
>   That looks as if it is something that should be built only on armv8... Since
> the build failure is in fact for an armv4, don't we have a bigger issue here?
> 
>   I believe 32-bit armv8 always has neon.

Would it be a good idea to provide a variable to enable or not building 
aes-armv8 and define or not USE_HW_AES? I mean, this is a Makefile and I 
don't know how to make libnss capable of understand if there is NEON 
support or not, do you have any suggestions?

>> +@@ -7,7 +7,8 @@
>> +
>> + #if (defined(__clang__) ||                            \
>> +      (defined(__GNUC__) && defined(__GNUC_MINOR__) && \
>> +-      (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ > 8))))
>> ++      (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ > 8))) && \
>> ++      (defined(__ARM_NEON) || defined(__ARM_NEON__)))
> 
>   That parenthesis matching doesn't look right... I suppose with clang it doesn't
> magically support neon, right? So there should be an additional set of
> parenthesis around the defined(__clang__) ... > 8 part.

Oops again, you're right.

Thanks for reviewing
Best regards
-- 
Giulio Benetti
Benetti Engineering sas