# git rev-parse -q --verify c21f5a9ed85ca3e914ca11f421677ae9ae0d04b0^{commit}
c21f5a9ed85ca3e914ca11f421677ae9ae0d04b0
already have revision, skipping fetch
# git checkout -q -f -B kisskb c21f5a9ed85ca3e914ca11f421677ae9ae0d04b0
# git clean -qxdf
# < git log -1
# commit c21f5a9ed85ca3e914ca11f421677ae9ae0d04b0
# Author: Christophe Leroy <christophe.leroy@c-s.fr>
# Date:   Mon Jun 3 13:00:51 2019 +0000
# 
#     powerpc/32s: fix booting with CONFIG_PPC_EARLY_DEBUG_BOOTX
#     
#     When booting through OF, setup_disp_bat() does nothing because
#     disp_BAT are not set. By change, it used to work because BOOTX
#     buffer is mapped 1:1 at address 0x81000000 by the bootloader, and
#     btext_setup_display() sets virt addr same as phys addr.
#     
#     But since commit 215b823707ce ("powerpc/32s: set up an early static
#     hash table for KASAN."), a temporary page table overrides the
#     bootloader mapping.
#     
#     This 0x81000000 is also problematic with the newly implemented
#     Kernel Userspace Access Protection (KUAP) because it is within user
#     address space.
#     
#     This patch fixes those issues by properly setting disp_BAT through
#     a call to btext_prepare_BAT(), allowing setup_disp_bat() to
#     properly setup BAT3 for early bootx screen buffer access.
#     
#     Reported-by: Mathieu Malaterre <malat@debian.org>
#     Fixes: 215b823707ce ("powerpc/32s: set up an early static hash table for KASAN.")
#     Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
#     Tested-by: Mathieu Malaterre <malat@debian.org>
#     Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
# < /opt/cross/kisskb/br-microblaze-full-2016.08-613-ge98b4dd/bin/microblazeel-linux-gcc --version
# < /opt/cross/kisskb/br-microblaze-full-2016.08-613-ge98b4dd/bin/microblazeel-linux-ld --version
# < git log --format=%s --max-count=1 c21f5a9ed85ca3e914ca11f421677ae9ae0d04b0
# < make -s -j 120 ARCH=microblaze O=/kisskb/build/powerpc-fixes_mmu_defconfig_microblaze CROSS_COMPILE=/opt/cross/kisskb/br-microblaze-full-2016.08-613-ge98b4dd/bin/microblazeel-linux-  mmu_defconfig
# make -s -j 120 ARCH=microblaze O=/kisskb/build/powerpc-fixes_mmu_defconfig_microblaze CROSS_COMPILE=/opt/cross/kisskb/br-microblaze-full-2016.08-613-ge98b4dd/bin/microblazeel-linux-  
Kernel: arch/microblaze/boot/linux.bin is ready  (#1)
Completed OK
# rm -rf /kisskb/build/powerpc-fixes_mmu_defconfig_microblaze
# Build took: 0:00:29.926841