# git rev-parse -q --verify c14cbef0319d21339a76247c3061230ae2950a7c^{commit}
c14cbef0319d21339a76247c3061230ae2950a7c
already have revision, skipping fetch
# git checkout -q -f -B kisskb c14cbef0319d21339a76247c3061230ae2950a7c
# git clean -qxdf
# < git log -1
# commit c14cbef0319d21339a76247c3061230ae2950a7c
# Author: Christophe Leroy <christophe.leroy@c-s.fr>
# Date:   Mon Jun 3 08:20:28 2019 +0000
# 
#     powerpc: fix kexec failure on book3s/32
#     
#     In the old days, _PAGE_EXEC didn't exist on 6xx aka book3s/32.
#     Therefore, allthough __mapin_ram_chunk() was already mapping kernel
#     text with PAGE_KERNEL_TEXT and the rest with PAGE_KERNEL, the entire
#     memory was executable. Part of the memory (first 512kbytes) was
#     mapped with BATs instead of page table, but it was also entirely
#     mapped as executable.
#     
#     In commit 385e89d5b20f ("powerpc/mm: add exec protection on
#     powerpc 603"), we started adding exec protection to some 6xx, namely
#     the 603, for pages mapped via pagetables.
#     
#     Then, in commit 63b2bc619565 ("powerpc/mm/32s: Use BATs for
#     STRICT_KERNEL_RWX"), the exec protection was extended to BAT mapped
#     memory, so that really only the kernel text could be executed.
#     
#     The problem here is that kexec is based on copying some code into
#     upper part of memory then executing it from there in order to install
#     a fresh new kernel at its definitive location.
#     
#     However, the code is position independant and first part of it is
#     just there to deactivate the MMU and jump to the second part. So it
#     is possible to run this first part inplace instead of running the
#     copy. Once the MMU is off, there is no protection anymore and the
#     second part of the code will just run as before.
#     
#     Reported-by: Aaro Koskinen <aaro.koskinen@iki.fi>
#     Fixes: 63b2bc619565 ("powerpc/mm/32s: Use BATs for STRICT_KERNEL_RWX")
#     Cc: stable@vger.kernel.org
#     Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
#     Tested-by: Aaro Koskinen <aaro.koskinen@iki.fi>
#     Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
# < /opt/cross/kisskb/gcc-4.6.3-nolibc/mips-linux/bin/mips-linux-gcc --version
# < /opt/cross/kisskb/gcc-4.6.3-nolibc/mips-linux/bin/mips-linux-ld --version
# < git log --format=%s --max-count=1 c14cbef0319d21339a76247c3061230ae2950a7c
# < make -s -j 80 ARCH=mips O=/kisskb/build/powerpc-fixes_mips-defconfig_mips CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/mips-linux/bin/mips-linux-  defconfig
# make -s -j 80 ARCH=mips O=/kisskb/build/powerpc-fixes_mips-defconfig_mips CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/mips-linux/bin/mips-linux-  
/kisskb/src/arch/mips/vdso/Makefile:39: MIPS VDSO requires binutils >= 2.25
/kisskb/src/arch/mips/vdso/Makefile:39: MIPS VDSO requires binutils >= 2.25
/kisskb/src/kernel/printk/printk.c: In function 'devkmsg_sysctl_set_loglvl':
/kisskb/src/kernel/printk/printk.c:194:16: warning: 'old' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/kernel/rcu/srcutree.c: In function 'init_srcu_struct_fields':
/kisskb/src/kernel/rcu/srcutree.c:140:32: warning: 'levelspread[<U6c80>]' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/kernel/rcu/srcutree.c:88:6: note: 'levelspread[<U6c80>]' was declared here
/kisskb/src/fs/proc/inode.c: In function 'proc_reg_open':
/kisskb/src/include/linux/list.h:65:12: warning: 'pdeo' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/fs/proc/inode.c:331:21: note: 'pdeo' was declared here
/kisskb/src/drivers/base/regmap/regmap.c: In function '_regmap_raw_write':
/kisskb/src/drivers/base/regmap/regmap.c:1850:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/base/regmap/regmap.c: In function 'regmap_raw_read':
/kisskb/src/drivers/base/regmap/regmap.c:2589:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/net/bridge/br_netlink.c: In function 'br_afspec.isra.20':
/kisskb/src/net/bridge/br_netlink.c:652:7: warning: 'err' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/net/core/devlink.c: In function 'devlink_fmsg_snd.constprop.30':
/kisskb/src/net/core/devlink.c:4394:6: warning: 'err' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/tty/serial/8250/8250_core.c: In function 'univ8250_release_irq':
/kisskb/src/drivers/tty/serial/8250/8250_core.c:247:18: warning: 'i' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/tty/serial/8250/8250_core.c:227:19: note: 'i' was declared here
/kisskb/src/arch/mips/vdso/Makefile:39: MIPS VDSO requires binutils >= 2.25
/kisskb/src/kernel/printk/printk.c: In function 'devkmsg_sysctl_set_loglvl':
/kisskb/src/kernel/printk/printk.c:194:16: warning: 'old' may be used uninitialized in this function [-Wuninitialized]
FIT description: Linux 5.2.0-rc2-gc14cbef0319d
Created:         Fri Jun  7 01:04:09 2019
 Image 0 (kernel@0)
  Description:  Linux 5.2.0-rc2-gc14cbef0319d
  Created:      Fri Jun  7 01:04:09 2019
  Type:         Kernel Image
  Compression:  gzip compressed
  Data Size:    4474879 Bytes = 4370.00 KiB = 4.27 MiB
  Architecture: MIPS
  OS:           Linux
  Load Address: 0x80100000
  Entry Point:  0x8084a950
  Hash algo:    sha1
  Hash value:   8c8c5784dceeadc7043f8c388ec5162b03ed0afb
 Image 1 (fdt@boston)
  Description:  img,boston Device Tree
  Created:      Fri Jun  7 01:04:09 2019
  Type:         Flat Device Tree
  Compression:  uncompressed
  Data Size:    3793 Bytes = 3.70 KiB = 0.00 MiB
  Architecture: MIPS
  Hash algo:    sha1
  Hash value:   4799f50d688573234da6e9d7701234d394759ef4
 Image 2 (fdt@ni169445)
  Description:  NI 169445 device tree
  Created:      Fri Jun  7 01:04:09 2019
  Type:         Flat Device Tree
  Compression:  uncompressed
  Data Size:    1871 Bytes = 1.83 KiB = 0.00 MiB
  Architecture: MIPS
  Hash algo:    sha1
  Hash value:   51b89b31605ee62038c8468c429af091dfc75ec7
 Image 3 (fdt@ocelot_pcb123)
  Description:  MSCC Ocelot PCB123 Device Tree
  Created:      Fri Jun  7 01:04:09 2019
  Type:         Flat Device Tree
  Compression:  uncompressed
  Data Size:    4603 Bytes = 4.50 KiB = 0.00 MiB
  Architecture: MIPS
  Hash algo:    sha1
  Hash value:   33e429f316125d86bb863c2fe8d9c42fbcf90bfb
 Image 4 (fdt@ocelot_pcb120)
  Description:  MSCC Ocelot PCB120 Device Tree
  Created:      Fri Jun  7 01:04:09 2019
  Type:         Flat Device Tree
  Compression:  uncompressed
  Data Size:    5162 Bytes = 5.04 KiB = 0.00 MiB
  Architecture: MIPS
  Hash algo:    sha1
  Hash value:   0c5db3f23ba8b80fafd8c8e4eacfcb8ad62a91ae
 Image 5 (fdt@xilfpga)
  Description:  MIPSfpga (xilfpga) Device Tree
  Created:      Fri Jun  7 01:04:09 2019
  Type:         Flat Device Tree
  Compression:  uncompressed
  Data Size:    2708 Bytes = 2.64 KiB = 0.00 MiB
  Architecture: MIPS
  Hash algo:    sha1
  Hash value:   63d058b780f65e22da30f0a183433765f1807f1d
 Default Configuration: 'conf@default'
 Configuration 0 (conf@default)
  Description:  Generic Linux kernel
  Kernel:       kernel@0
 Configuration 1 (conf@boston)
  Description:  Boston Linux kernel
  Kernel:       kernel@0
  FDT:          fdt@boston
 Configuration 2 (conf@ni169445)
  Description:  NI 169445 Linux Kernel
  Kernel:       kernel@0
  FDT:          fdt@ni169445
 Configuration 3 (conf@ocelot_pcb123)
  Description:  Ocelot Linux kernel
  Kernel:       kernel@0
  FDT:          fdt@ocelot_pcb123
 Configuration 4 (conf@ocelot_pcb120)
  Description:  Ocelot Linux kernel
  Kernel:       kernel@0
  FDT:          fdt@ocelot_pcb120
 Configuration 5 (conf@xilfpga)
  Description:  MIPSfpga Linux kernel
  Kernel:       kernel@0
  FDT:          fdt@xilfpga
Completed OK
# rm -rf /kisskb/build/powerpc-fixes_mips-defconfig_mips
# Build took: 0:01:37.207745