# git rev-parse -q --verify 397758385ba96da48a96f82cf3521f994f3a78b3^{commit}
397758385ba96da48a96f82cf3521f994f3a78b3
already have revision, skipping fetch
# git checkout -q -f -B kisskb 397758385ba96da48a96f82cf3521f994f3a78b3
# git clean -qxdf
# < git log -1
# commit 397758385ba96da48a96f82cf3521f994f3a78b3
# Author: Michael Ellerman <mpe@ellerman.id.au>
# Date:   Tue Jul 10 16:20:56 2018 +1000
# 
#     powerpc/uaccess: Enable get_user(u64, *p) on 32-bit
#     
#     Currently if you build a 32-bit powerpc kernel and use get_user() to
#     load a u64 value it will fail to build with eg:
#     
#       kernel/rseq.o: In function `rseq_get_rseq_cs':
#       kernel/rseq.c:123: undefined reference to `__get_user_bad'
#     
#     This is hitting the check in __get_user_size() that makes sure the
#     size we're copying doesn't exceed the size of the destination:
#     
#       #define __get_user_size(x, ptr, size, retval)
#       do {
#       	retval = 0;
#       	__chk_user_ptr(ptr);
#       	if (size > sizeof(x))
#       		(x) = __get_user_bad();
#     
#     Which doesn't immediately make sense because the size of the
#     destination is u64, but it's not really, because __get_user_check()
#     etc. internally create an unsigned long and copy into that:
#     
#       #define __get_user_check(x, ptr, size)
#       ({
#       	long __gu_err = -EFAULT;
#       	unsigned long  __gu_val = 0;
#     
#     The problem being that on 32-bit unsigned long is not big enough to
#     hold a u64. We can fix this with a trick from hpa in the x86 code, we
#     statically check the type of x and set the type of __gu_val to either
#     unsigned long or unsigned long long.
#     
#     Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
# < /opt/cross/kisskb/gcc-5.3.0-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc --version
# < git log --format=%s --max-count=1 397758385ba96da48a96f82cf3521f994f3a78b3
# < make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-next_85xx_tqm8555_defconfig_powerpc-5.3 CROSS_COMPILE=/opt/cross/kisskb/gcc-5.3.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  85xx/tqm8555_defconfig
# make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-next_85xx_tqm8555_defconfig_powerpc-5.3 CROSS_COMPILE=/opt/cross/kisskb/gcc-5.3.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  
/kisskb/src/net/Makefile:24: CC cannot link executables. Skipping bpfilter.
INFO: Uncompressed kernel (size 0x4ca810) overlaps the address of the wrapper(0x400000)
INFO: Fixing the link_address of wrapper to (0x500000)
INFO: Uncompressed kernel (size 0x4ba164) overlaps the address of the wrapper(0x400000)
INFO: Fixing the link_address of wrapper to (0x500000)
Image Name:   Linux-4.18.0-rc3-g3977583
Created:      Tue Jul 10 18:08:05 2018
Image Type:   PowerPC Linux Kernel Image (gzip compressed)
Data Size:    2454722 Bytes = 2397.19 kB = 2.34 MB
Load Address: 00000000
Entry Point:  00000000
Image Name:   Linux-4.18.0-rc3-g3977583
Created:      Tue Jul 10 18:08:05 2018
Image Type:   PowerPC Linux Kernel Image (gzip compressed)
Data Size:    2478674 Bytes = 2420.58 kB = 2.36 MB
Load Address: 00500000
Entry Point:  00500278
Completed OK
# rm -rf /kisskb/build/powerpc-next_85xx_tqm8555_defconfig_powerpc-5.3
# Build took: 0:00:38.504505