# git rev-parse -q --verify 90e603ca59646651c0f13d54d7b2b0c630c96998^{commit}
90e603ca59646651c0f13d54d7b2b0c630c96998
already have revision, skipping fetch
# git checkout -q -f -B kisskb 90e603ca59646651c0f13d54d7b2b0c630c96998
# git clean -qxdf
# < git log -1
# commit 90e603ca59646651c0f13d54d7b2b0c630c96998
# Author: Christophe Leroy <christophe.leroy@csgroup.eu>
# Date:   Mon Oct 19 10:13:39 2020 +0000
# 
#     powerpc/uaccess: Don't use "m<>" constraint with GCC 4.9
#     
#     GCC 4.9 sometimes fails to build with "m<>" constraint in
#     inline assembly.
#     
#       CC      lib/iov_iter.o
#     In file included from ./arch/powerpc/include/asm/cmpxchg.h:6:0,
#                      from ./arch/powerpc/include/asm/atomic.h:11,
#                      from ./include/linux/atomic.h:7,
#                      from ./include/linux/crypto.h:15,
#                      from ./include/crypto/hash.h:11,
#                      from lib/iov_iter.c:2:
#     lib/iov_iter.c: In function 'iovec_from_user.part.30':
#     ./arch/powerpc/include/asm/uaccess.h:287:2: error: 'asm' operand has impossible constraints
#       __asm__ __volatile__(    \
#       ^
#     ./include/linux/compiler.h:78:42: note: in definition of macro 'unlikely'
#      # define unlikely(x) __builtin_expect(!!(x), 0)
#                                               ^
#     ./arch/powerpc/include/asm/uaccess.h:583:34: note: in expansion of macro 'unsafe_op_wrap'
#      #define unsafe_get_user(x, p, e) unsafe_op_wrap(__get_user_allowed(x, p), e)
#                                       ^
#     ./arch/powerpc/include/asm/uaccess.h:329:10: note: in expansion of macro '__get_user_asm'
#       case 4: __get_user_asm(x, (u32 __user *)ptr, retval, "lwz"); break; \
#               ^
#     ./arch/powerpc/include/asm/uaccess.h:363:3: note: in expansion of macro '__get_user_size_allowed'
#        __get_user_size_allowed(__gu_val, __gu_addr, __gu_size, __gu_err); \
#        ^
#     ./arch/powerpc/include/asm/uaccess.h:100:2: note: in expansion of macro '__get_user_nocheck'
#       __get_user_nocheck((x), (ptr), sizeof(*(ptr)), false)
#       ^
#     ./arch/powerpc/include/asm/uaccess.h:583:49: note: in expansion of macro '__get_user_allowed'
#      #define unsafe_get_user(x, p, e) unsafe_op_wrap(__get_user_allowed(x, p), e)
#                                                      ^
#     lib/iov_iter.c:1663:3: note: in expansion of macro 'unsafe_get_user'
#        unsafe_get_user(len, &uiov[i].iov_len, uaccess_end);
#        ^
#     make[1]: *** [scripts/Makefile.build:283: lib/iov_iter.o] Error 1
#     
#     Define a UPD_CONSTR macro that is "<>" by default and
#     only "" with GCC prior to GCC 5.
#     
#     Fixes: fcf1f26895a4 ("powerpc/uaccess: Add pre-update addressing to __put_user_asm_goto()")
#     Fixes: 2f279eeb68b8 ("powerpc/uaccess: Add pre-update addressing to __get_user_asm() and __put_user_asm()")
#     Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
#     Acked-by: Segher Boessenkool <segher@kernel.crashing.org>
#     ---
#     v2: Moved UPD_CONSTR to asm-const.h to avoid circular inclusion issues with patch 3.
# < /opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc --version
# < /opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux-ld --version
# < git log --format=%s --max-count=1 90e603ca59646651c0f13d54d7b2b0c630c96998
# < make -s -j 48 ARCH=powerpc O=/kisskb/build/chleroy_ppc64_defconfig+NO_HUGETLB_powerpc-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux-  ppc64_defconfig
# Added to kconfig CONFIG_HUGETLBFS=n
# < make -s -j 48 ARCH=powerpc O=/kisskb/build/chleroy_ppc64_defconfig+NO_HUGETLB_powerpc-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux-  help
# make -s -j 48 ARCH=powerpc O=/kisskb/build/chleroy_ppc64_defconfig+NO_HUGETLB_powerpc-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux-  olddefconfig
# make -s -j 48 ARCH=powerpc O=/kisskb/build/chleroy_ppc64_defconfig+NO_HUGETLB_powerpc-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux-  
/kisskb/src/fs/btrfs/tree-checker.c: In function 'check_root_item':
/kisskb/src/fs/btrfs/tree-checker.c:1038:9: warning: missing braces around initializer [-Wmissing-braces]
  struct btrfs_root_item ri = { 0 };
         ^
/kisskb/src/fs/btrfs/tree-checker.c:1038:9: warning: (near initialization for 'ri.inode') [-Wmissing-braces]
Completed OK
# rm -rf /kisskb/build/chleroy_ppc64_defconfig+NO_HUGETLB_powerpc-gcc4.9
# Build took: 0:03:25.062293