• Will Deacon's avatar
    tools headers barrier: Fix arm64 tools build failure wrt smp_load_{acquire,release} · 51f5fd2e
    Will Deacon authored
    Cheers for reporting this. I managed to reproduce the build failure with
    gcc version 6.3.0 20170516 (Debian 6.3.0-18+deb9u1).
    
    The code in question is the arm64 versions of smp_load_acquire() and
    smp_store_release(). Unlike other architectures, these are not built
    around READ_ONCE() and WRITE_ONCE() since we have instructions we can
    use instead of fences. Bringing our macros up-to-date with those (i.e.
    tweaking the union initialisation and using the special "uXX_alias_t"
    types) appears to fix the issue for me.
    
    Committer notes:
    
    Testing it in the systems previously failing:
    
      # time dm android-ndk:r12b-arm \
             android-ndk:r15c-arm \
             debian:experimental-x-arm64 \
             ubuntu:14.04.4-x-linaro-arm64 \
             ubuntu:16.04-x-arm \
             ubuntu:16.04-x-arm64 \
             ubuntu:18.04-x-arm \
             ubuntu:18.04-x-arm64
        1 android-ndk:r12b-arm          : Ok   arm-linux-androideabi-gcc (GCC) 4.9.x 20150123 (prerelease)
        2 android-ndk:r15c-arm          : Ok   arm-linux-androideabi-gcc (GCC) 4.9.x 20150123 (prerelease)
        3 debian:experimental-x-arm64   : Ok   aarch64-linux-gnu-gcc (Debian 8.2.0-7) 8.2.0
        4 ubuntu:14.04.4-x-linaro-arm64 : Ok   aarch64-linux-gnu-gcc (Linaro GCC 5.5-2017.10) 5.5.0
        5 ubuntu:16.04-x-arm            : Ok   arm-linux-gnueabihf-gcc (Ubuntu/Linaro 5.4.0-6ubuntu1~16.04.9) 5.4.0 20160609
        6 ubuntu:16.04-x-arm64          : Ok   aarch64-linux-gnu-gcc (Ubuntu/Linaro 5.4.0-6ubuntu1~16.04.9) 5.4.0 20160609
        7 ubuntu:18.04-x-arm            : Ok   arm-linux-gnueabihf-gcc (Ubuntu/Linaro 7.3.0-27ubuntu1~18.04) 7.3.0
        8 ubuntu:18.04-x-arm64          : Ok   aarch64-linux-gnu-gcc (Ubuntu/Linaro 7.3.0-27ubuntu1~18.04) 7.3.0
    Reported-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
    Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
    Tested-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
    Tested-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Link: http://lkml.kernel.org/r/20181031174408.GA27871@arm.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
    51f5fd2e
barrier.h 2.34 KB