# git rev-parse -q --verify cafa0010cd51fb711fdcb50fc55f394c5f167a0a^{commit}
cafa0010cd51fb711fdcb50fc55f394c5f167a0a
already have revision, skipping fetch
# git checkout -q -f -B kisskb cafa0010cd51fb711fdcb50fc55f394c5f167a0a
# git clean -qxdf
# < git log -1
# commit cafa0010cd51fb711fdcb50fc55f394c5f167a0a
# Author: Joe Perches <joe@perches.com>
# Date:   Mon Aug 20 13:15:26 2018 -0700
# 
#     Raise the minimum required gcc version to 4.6
#     
#     Various architectures fail to build properly with older versions of the
#     gcc compiler.
#     
#     An example from Guenter Roeck in thread [1]:
#     >
#     >   In file included from ./include/linux/mm.h:17:0,
#     >                    from ./include/linux/pid_namespace.h:7,
#     >                    from ./include/linux/ptrace.h:10,
#     >                    from arch/openrisc/kernel/asm-offsets.c:32:
#     >   ./include/linux/mm_types.h:497:16: error: flexible array member in otherwise empty struct
#     >
#     > This is just an example with gcc 4.5.1 for or32. I have seen the problem
#     > with gcc 4.4 (for unicore32) as well.
#     
#     So update the minimum required version of gcc to 4.6.
#     
#     [1] https://lore.kernel.org/lkml/20180814170904.GA12768@roeck-us.net/
#     
#     Miscellanea:
#     
#      - Update Documentation/process/changes.rst
#     
#      - Remove and consolidate version test blocks in compiler-gcc.h for
#        versions lower than 4.6
#     
#     Signed-off-by: Joe Perches <joe@perches.com>
#     Reviewed-by: Kees Cook <keescook@chromium.org>
#     Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
#     Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
# < /opt/cross/kisskb/fe-x86-64-core-i7-2017.05/bin/x86_64-linux-gcc --version
# < git log --format=%s --max-count=1 cafa0010cd51fb711fdcb50fc55f394c5f167a0a
# < make -s -j 48 ARCH=um O=/kisskb/build/linus_um-defconfig_um-x86_64 CROSS_COMPILE=/opt/cross/kisskb/fe-x86-64-core-i7-2017.05/bin/x86_64-linux- SUBARCH=x86_64 defconfig
# make -s -j 48 ARCH=um O=/kisskb/build/linus_um-defconfig_um-x86_64 CROSS_COMPILE=/opt/cross/kisskb/fe-x86-64-core-i7-2017.05/bin/x86_64-linux- SUBARCH=x86_64 
/kisskb/src/arch/um/os-Linux/skas/process.c: In function 'start_idle_thread':
/kisskb/src/arch/um/os-Linux/skas/process.c:613:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
/kisskb/src/net/core/rtnetlink.c: In function 'rtnl_newlink':
/kisskb/src/net/core/rtnetlink.c:3148:1: warning: the frame size of 1296 bytes is larger than 1024 bytes [-Wframe-larger-than=]
 }
 ^
  LINK linux
Completed OK
# rm -rf /kisskb/build/linus_um-defconfig_um-x86_64
# Build took: 0:00:36.037837