# git rev-parse -q --verify 8dcd71b45df34d9b903450fab147ee8c1e6c16b5^{commit}
8dcd71b45df34d9b903450fab147ee8c1e6c16b5
already have revision, skipping fetch
# git checkout -q -f -B kisskb 8dcd71b45df34d9b903450fab147ee8c1e6c16b5
# git clean -qxdf
# < git log -1
# commit 8dcd71b45df34d9b903450fab147ee8c1e6c16b5
# Author: Nathan Chancellor <natechancellor@gmail.com>
# Date:   Mon Nov 18 21:57:12 2019 -0700
# 
#     powerpc/prom_init: Use -ffreestanding to avoid a reference to bcmp
#     
#     LLVM revision r374662 gives LLVM the ability to convert certain loops
#     into a reference to bcmp as an optimization; this breaks
#     prom_init_check.sh:
#     
#         CALL    arch/powerpc/kernel/prom_init_check.sh
#       Error: External symbol 'bcmp' referenced from prom_init.c
#       make[2]: *** [arch/powerpc/kernel/Makefile:196: prom_init_check] Error 1
#     
#     bcmp is defined in lib/string.c as a wrapper for memcmp so this could
#     be added to the whitelist. However, commit
#     450e7dd4001f ("powerpc/prom_init: don't use string functions from
#     lib/") copied memcmp as prom_memcmp to avoid KASAN instrumentation so
#     having bcmp be resolved to regular memcmp would break that assumption.
#     Furthermore, because the compiler is the one that inserted bcmp, we
#     cannot provide something like prom_bcmp.
#     
#     To prevent LLVM from being clever with optimizations like this, use
#     -ffreestanding to tell LLVM we are not hosted so it is not free to
#     make transformations like this.
#     
#     Reviewed-by: Nick Desaulneris <ndesaulniers@google.com>
#     Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
#     Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
#     Link: https://lore.kernel.org/r/20191119045712.39633-4-natechancellor@gmail.com
# < /opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/aarch64-linux-gcc --version
# < /opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/aarch64-linux-ld --version
# < git log --format=%s --max-count=1 8dcd71b45df34d9b903450fab147ee8c1e6c16b5
# < make -s -j 120 ARCH=arm64 O=/kisskb/build/powerpc-next_arm64-defconfig_arm64-gcc5.4 CROSS_COMPILE=/opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/aarch64-linux-  defconfig
# make -s -j 120 ARCH=arm64 O=/kisskb/build/powerpc-next_arm64-defconfig_arm64-gcc5.4 CROSS_COMPILE=/opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/aarch64-linux-  
arch/arm64/Makefile:27: ld does not support --fix-cortex-a53-843419; kernel may be susceptible to erratum
arch/arm64/Makefile:38: LSE atomics not supported by binutils
arch/arm64/Makefile:62: CROSS_COMPILE_COMPAT not defined or empty, the compat vDSO will not be built
In file included from /kisskb/src/include/linux/list.h:9:0,
                 from /kisskb/src/include/linux/wait.h:7,
                 from /kisskb/src/include/linux/wait_bit.h:8,
                 from /kisskb/src/include/linux/fs.h:6,
                 from /kisskb/src/fs/btrfs/send.c:7:
/kisskb/src/fs/btrfs/send.c: In function 'process_extent':
/kisskb/src/include/linux/kernel.h:37:33: warning: 'clone_src_i_size' may be used uninitialized in this function [-Wmaybe-uninitialized]
 #define IS_ALIGNED(x, a)  (((x) & ((typeof(x))(a) - 1)) == 0)
                                 ^
/kisskb/src/fs/btrfs/send.c:5088:6: note: 'clone_src_i_size' was declared here
  u64 clone_src_i_size;
      ^
/kisskb/src/drivers/i2c/busses/i2c-sh_mobile.c: In function 'sh_mobile_i2c_isr':
/kisskb/src/drivers/i2c/busses/i2c-sh_mobile.c:399:26: warning: 'data' may be used uninitialized in this function [-Wmaybe-uninitialized]
   pd->msg->buf[real_pos] = data;
                          ^
/kisskb/src/drivers/i2c/busses/i2c-sh_mobile.c:372:16: note: 'data' was declared here
  unsigned char data;
                ^
In file included from /kisskb/src/include/linux/rwsem.h:16:0,
                 from /kisskb/src/include/linux/notifier.h:15,
                 from /kisskb/src/include/linux/clk.h:14,
                 from /kisskb/src/drivers/tty/serial/sh-sci.c:24:
/kisskb/src/drivers/tty/serial/sh-sci.c: In function 'sci_dma_rx_submit':
/kisskb/src/include/linux/spinlock.h:288:3: warning: 'flags' may be used uninitialized in this function [-Wmaybe-uninitialized]
   _raw_spin_unlock_irqrestore(lock, flags); \
   ^
/kisskb/src/drivers/tty/serial/sh-sci.c:1351:16: note: 'flags' was declared here
  unsigned long flags;
                ^
Completed OK
# rm -rf /kisskb/build/powerpc-next_arm64-defconfig_arm64-gcc5.4
# Build took: 0:02:44.162105