# git rev-parse -q --verify cb42033f5d172b5779b6c8301c65693ff6a0a778^{commit}
cb42033f5d172b5779b6c8301c65693ff6a0a778
already have revision, skipping fetch
# git checkout -q -f -B kisskb cb42033f5d172b5779b6c8301c65693ff6a0a778
# git clean -qxdf
# < git log -1
# commit cb42033f5d172b5779b6c8301c65693ff6a0a778
# Author: Christophe Leroy <christophe.leroy@c-s.fr>
# Date:   Mon Mar 11 08:30:38 2019 +0000
# 
#     powerpc/32s: Implement Kernel Userspace Access Protection
#     
#     This patch implements Kernel Userspace Access Protection for
#     book3s/32.
#     
#     Due to limitations of the processor page protection capabilities,
#     the protection is only against writing. read protection cannot be
#     achieved using page protection.
#     
#     The previous patch modifies the page protection so that RW user
#     pages are RW for Key 0 and RO for Key 1, and it sets Key 0 for
#     both user and kernel.
#     
#     This patch changes userspace segment registers are set to Ku 0
#     and Ks 1. When kernel needs to write to RW pages, the associated
#     segment register is then changed to Ks 0 in order to allow write
#     access to the kernel.
#     
#     In order to avoid having the read all segment registers when
#     locking/unlocking the access, some data is kept in the thread_struct
#     and saved on stack on exceptions. The field identifies both the
#     first unlocked segment and the first segment following the last
#     unlocked one. When no segment is unlocked, it contains value 0.
#     
#     As the hash_page() function is not able to easily determine if a
#     protfault is due to a bad kernel access to userspace, protfaults
#     need to be handled by handle_page_fault when KUAP is set.
#     
#     Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
#     [mpe: Drop allow_read/write_to/from_user() as they're now in kup.h,
#           and adapt allow_user_access() to do nothing when to == NULL]
#     Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
# < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc --version
# < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-ld --version
# < git log --format=%s --max-count=1 cb42033f5d172b5779b6c8301c65693ff6a0a778
# < make -s -j 48 ARCH=powerpc O=/kisskb/build/mpe_mpc885_ads_defconfig+HUGETLB_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  mpc885_ads_defconfig
# Added to kconfig CONFIG_HUGETLBFS=y
# yes \n | make -s -j 48 ARCH=powerpc O=/kisskb/build/mpe_mpc885_ads_defconfig+HUGETLB_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  oldconfig
yes: standard output: Broken pipe
# make -s -j 48 ARCH=powerpc O=/kisskb/build/mpe_mpc885_ads_defconfig+HUGETLB_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  
<stdin>:1478:2: warning: #warning syscall pidfd_send_signal not implemented [-Wcpp]
<stdin>:1481:2: warning: #warning syscall io_uring_setup not implemented [-Wcpp]
<stdin>:1484:2: warning: #warning syscall io_uring_enter not implemented [-Wcpp]
<stdin>:1487:2: warning: #warning syscall io_uring_register not implemented [-Wcpp]
WARNING: vmlinux.o(.text+0xac9c): Section mismatch in reference from the function setup_kup() to the function .init.text:setup_kuep()
The function setup_kup() references
the function __init setup_kuep().
This is often because setup_kup lacks a __init 
annotation or the annotation of setup_kuep is wrong.

WARNING: vmlinux.o(.text+0xacb4): Section mismatch in reference from the function setup_kup() to the function .init.text:setup_kuap()
The function setup_kup() references
the function __init setup_kuap().
This is often because setup_kup lacks a __init 
annotation or the annotation of setup_kuap is wrong.

Image Name:   Linux-5.1.0-rc3-gcb42033f5d17
Created:      Sat Apr 20 00:09:12 2019
Image Type:   PowerPC Linux Kernel Image (gzip compressed)
Data Size:    1896001 Bytes = 1851.56 KiB = 1.81 MiB
Load Address: 00400000
Entry Point:  00400204
Completed OK
# rm -rf /kisskb/build/mpe_mpc885_ads_defconfig+HUGETLB_powerpc-gcc5
# Build took: 0:00:43.298548