# 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/powerpc-linux/bin/powerpc-linux-gcc --version
# < /opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux-ld --version
# < git log --format=%s --max-count=1 c14cbef0319d21339a76247c3061230ae2950a7c
# < make -s -j 24 ARCH=powerpc O=/kisskb/build/powerpc-fixes_ps3_defconfig_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux-  ps3_defconfig
# make -s -j 24 ARCH=powerpc O=/kisskb/build/powerpc-fixes_ps3_defconfig_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux-  
/kisskb/src/ipc/shm.c: In function 'ksys_shmdt':
/kisskb/src/ipc/shm.c:1712:59: warning: 'file' 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[<U6640>]' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/kernel/rcu/srcutree.c:88:6: note: 'levelspread[<U6640>]' was declared here
/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/drivers/block/ps3vram.c: In function 'ps3vram_probe':
/kisskb/src/drivers/block/ps3vram.c:770:2: warning: format '%lu' expects argument of type 'long unsigned int', but argument 4 has type 'sector_t' [-Wformat]
/kisskb/src/kernel/futex.c: In function 'do_futex':
/kisskb/src/kernel/futex.c:1668:3: warning: 'oldval' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/kernel/futex.c:1633:6: note: 'oldval' was declared here
/kisskb/src/net/bluetooth/hidp/core.c: In function 'hidp_connection_add':
/kisskb/src/net/bluetooth/hidp/core.c:1381:18: warning: 'session' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/mm/vmalloc.c: In function 'alloc_vmap_area.isra.33':
/kisskb/src/mm/vmalloc.c:976:28: warning: 'lva' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/mm/vmalloc.c:916:20: note: 'lva' was declared here
/kisskb/src/mm/vmalloc.c: In function 'pcpu_get_vm_areas':
/kisskb/src/mm/vmalloc.c:976:28: warning: 'lva' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/mm/vmalloc.c:916:20: note: 'lva' was declared here
/kisskb/src/fs/cifs/smb2pdu.c: In function 'SMB2_ioctl_init':
/kisskb/src/fs/cifs/smb2pdu.c:2580:19: warning: 'in_data_buf' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/lib/mpi/mpicoder.c: In function 'mpi_read_raw_from_sgl':
/kisskb/src/lib/mpi/mpicoder.c:352:8: warning: 'buff' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/lib/rhashtable.c: In function 'rht_deferred_worker':
/kisskb/src/include/linux/rhashtable.h:110:10: warning: 'next' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/lib/rhashtable.c:225:28: note: 'next' was declared here
/kisskb/src/net/core/gen_stats.c: In function '__gnet_stats_copy_basic':
/kisskb/src/net/core/gen_stats.c:161:19: warning: 'seq' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/net/core/dev.c: In function 'validate_xmit_skb_list':
/kisskb/src/net/core/dev.c:3419:15: warning: 'tail' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/net/ipv6/ip6_output.c: In function '__ip6_append_data.isra.40':
/kisskb/src/include/linux/skbuff.h:1406:6: warning: 'extra_uref' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/net/ipv6/ip6_output.c:1278:14: note: 'extra_uref' 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/net/ipv4/ip_output.c: In function '__ip_append_data.isra.41':
/kisskb/src/include/linux/skbuff.h:1406:6: warning: 'extra_uref' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/net/ipv4/ip_output.c:881:14: note: 'extra_uref' was declared here
/kisskb/src/fs/udf/unicode.c: In function 'udf_name_conv_char':
/kisskb/src/fs/udf/unicode.c:132:8: warning: 'c' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/net/mac80211/tx.c: In function 'ieee80211_build_hdr':
/kisskb/src/net/mac80211/tx.c:2522:27: warning: 'chanctx_conf' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/net/mac80211/mlme.c: In function 'ieee80211_rx_mgmt_beacon':
/kisskb/src/net/mac80211/mlme.c:1578:3: warning: 'pwr_level_cisco' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/net/mac80211/mlme.c:1535:6: note: 'pwr_level_cisco' was declared here
WARNING: vmlinux.o(.text+0x322a): Section mismatch in reference from the variable start_here_multiplatform to the function .init.text:.early_setup()
The function start_here_multiplatform() references
the function __init .early_setup().
This is often because start_here_multiplatform lacks a __init 
annotation or the annotation of .early_setup is wrong.

Completed OK
# rm -rf /kisskb/build/powerpc-fixes_ps3_defconfig_powerpc-gcc4.6
# Build took: 0:01:37.585745