# git rev-parse -q --verify 7c8db8431b5bc1c37f6d2ce73d2e18a42b52c87d^{commit}
# git fetch -q -n -f git://gitlab.ozlabs.ibm.com/linuxppc/linux.git fixes-test
# git rev-parse -q --verify 7c8db8431b5bc1c37f6d2ce73d2e18a42b52c87d^{commit}
7c8db8431b5bc1c37f6d2ce73d2e18a42b52c87d
# git checkout -q -f -B kisskb 7c8db8431b5bc1c37f6d2ce73d2e18a42b52c87d
# git clean -qxdf
# < git log -1
# commit 7c8db8431b5bc1c37f6d2ce73d2e18a42b52c87d
# Author: Michael Ellerman <mpe@ellerman.id.au>
# Date:   Thu Apr 12 22:24:45 2018 +1000
# 
#     powerpc/64s: Fix CPU_FTRS_ALWAYS vs DT CPU features
#     
#     The cpu_has_feature() mechanism has an optimisation where at build
#     time we construct a mask of the CPU feature bits that will always be
#     true for the given .config, based on the platform/bitness/etc. that we
#     are building for.
#     
#     That is incompatible with DT CPU features, where the set of CPU
#     features is dependent on feature flags that are given to us by
#     firmware.
#     
#     The result is that some feature bits can not be *disabled* by DT CPU
#     features. Or more accurately, they can be disabled but they will still
#     appear in the ALWAYS mask, meaning cpu_has_feature() will always
#     return true for them.
#     
#     In the past this hasn't really been a problem because on Book3S
#     64 (where we support DT CPU features), the set of ALWAYS bits has been
#     very small. That was because we always built for POWER4 and later,
#     meaning the set of common bits was small.
#     
#     The only bit that could be cleared by DT CPU features that was also in
#     the ALWAYS mask was CPU_FTR_NODSISRALIGN, and that was only used in
#     the alignment handler to create a fake DSISR. That code was itself
#     deleted in 31bfdb036f12 ("powerpc: Use instruction emulation
#     infrastructure to handle alignment faults") (Sep 2017).
#     
#     However the set of ALWAYS features changed with the recent commit
#     db5ae1c155af ("powerpc/64s: Refine feature sets for little endian
#     builds") which restricted the set of feature flags when building
#     little endian to Power7 or later. That caused the ALWAYS mask to
#     become much larger for little endian builds.
#     
#     The result is that the following feature bits can currently not
#     be *disabled* by DT CPU features:
#     
#       CPU_FTR_REAL_LE, CPU_FTR_MMCRA, CPU_FTR_CTRL, CPU_FTR_SMT,
#       CPU_FTR_PURR, CPU_FTR_SPURR, CPU_FTR_DSCR, CPU_FTR_PKEY,
#       CPU_FTR_VMX_COPY, CPU_FTR_CFAR, CPU_FTR_HAS_PPR.
#     
#     To fix it we need to mask the set of ALWAYS features with the base set
#     of DT CPU features, ie. the features that are always enabled by DT CPU
#     features. That way there are no bits in the ALWAYS mask that are not
#     also always set by DT CPU features.
#     
#     Fixes: db5ae1c155af ("powerpc/64s: Refine feature sets for little endian builds")
#     Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
# < /opt/cross/kisskb/gcc-4.6.3-nolibc/m68k-linux/bin/m68k-linux-gcc --version
# < git log --format=%s --max-count=1 7c8db8431b5bc1c37f6d2ce73d2e18a42b52c87d
# < make -s -j 48 ARCH=m68k O=/kisskb/build/powerpc-fixes_m68k-defconfig_m68k CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/m68k-linux/bin/m68k-linux-  defconfig
arch/m68k/configs/multi_defconfig:108:warning: symbol value 'm' invalid for NF_TABLES_INET
arch/m68k/configs/multi_defconfig:109:warning: symbol value 'm' invalid for NF_TABLES_NETDEV
arch/m68k/configs/multi_defconfig:214:warning: symbol value 'm' invalid for NF_TABLES_ARP
arch/m68k/configs/multi_defconfig:269:warning: symbol value 'm' invalid for NF_TABLES_BRIDGE
# make -s -j 48 ARCH=m68k O=/kisskb/build/powerpc-fixes_m68k-defconfig_m68k CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/m68k-linux/bin/m68k-linux-  
<stdin>:1239:2: warning: #warning syscall seccomp not implemented [-Wcpp]
<stdin>:1317:2: warning: #warning syscall pkey_mprotect not implemented [-Wcpp]
<stdin>:1320:2: warning: #warning syscall pkey_alloc not implemented [-Wcpp]
<stdin>:1323:2: warning: #warning syscall pkey_free not implemented [-Wcpp]
/kisskb/src/arch/m68k/mvme147/config.c: In function 'mvme147_hwclk':
/kisskb/src/arch/m68k/mvme147/config.c:152:2: warning: #warning check me! [-Wcpp]
/kisskb/src/arch/m68k/mvme16x/config.c: In function 'mvme16x_hwclk':
/kisskb/src/arch/m68k/mvme16x/config.c:399:2: warning: #warning check me! [-Wcpp]
/kisskb/src/ipc/shm.c: In function 'ksys_shmdt':
/kisskb/src/ipc/shm.c:1607:59: warning: 'file' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/kernel/acct.c: In function 'acct_pin_kill':
/kisskb/src/kernel/acct.c:177:2: warning: value computed is not used [-Wunused-value]
/kisskb/src/kernel/printk/printk.c: In function 'devkmsg_sysctl_set_loglvl':
/kisskb/src/kernel/printk/printk.c:182:16: warning: 'old' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/kernel/bpf/syscall.c:1229:12: warning: 'bpf_prog_attach_check_attach_type' defined but not used [-Wunused-function]
/kisskb/src/lib/rhashtable.c: In function 'rht_deferred_worker':
/kisskb/src/lib/rhashtable.c:269:2: warning: 'next' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/lib/rhashtable.c:234:28: 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:149:19: warning: 'seq' 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:336:12: warning: 'buff' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/net/core/flow_dissector.c: In function '__skb_flow_dissect':
/kisskb/src/net/core/flow_dissector.c:789:7: warning: 'vlan' 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:3176:15: warning: 'tail' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/fs/posix_acl.c: In function 'get_acl':
/kisskb/src/fs/posix_acl.c:147:3: warning: value computed is not used [-Wunused-value]
/kisskb/src/fs/udf/unicode.c: In function 'udf_name_conv_char':
/kisskb/src/fs/udf/unicode.c:157:15: warning: 'c' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/fs/ocfs2/file.c: In function 'ocfs2_file_write_iter':
/kisskb/src/fs/ocfs2/file.c:2386:3: warning: value computed is not used [-Wunused-value]
/kisskb/src/drivers/net/macsec.c: In function 'macsec_del_rxsa':
/kisskb/src/drivers/net/macsec.c:1926:2: warning: 'assoc_num' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/net/macsec.c:1926:2: warning: 'rx_sc' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/net/macsec.c: In function 'macsec_del_txsa':
/kisskb/src/drivers/net/macsec.c:2003:2: warning: 'assoc_num' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/net/macsec.c:2003:2: warning: 'tx_sc' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/net/macsec.c: In function 'macsec_upd_txsa':
/kisskb/src/drivers/net/macsec.c:2068:5: warning: 'assoc_num' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/net/macsec.c:2068:24: warning: 'tx_sc' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/net/macsec.c:2069:21: warning: 'secy' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/net/tun.c: In function 'tun_get_user':
/kisskb/src/drivers/net/tun.c:1820:30: warning: 'copylen' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/net/tun.c:1530:31: warning: 'linear' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/net/tun.c:1730:46: note: 'linear' was declared here
Completed OK
# rm -rf /kisskb/build/powerpc-fixes_m68k-defconfig_m68k
# Build took: 0:01:35.432083