Buildresult: powerpc-fixes/corenet_basic_defconfig/powerpc-gcc4.6 built on Apr 14 2018, 01:03

kisskb

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Status:	OK
Date/Time:	Apr 14 2018, 01:03
Duration:	0:00:22.596516
Builder:	ka3
Revision:	powerpc/64s: Fix CPU_FTRS_ALWAYS vs DT CPU features (`81b654c273914704a4bdf580f28d67aaba1094e4)`
Target:	powerpc-fixes/corenet_basic_defconfig/powerpc-gcc4.6
Branch:	powerpc-fixes
Compiler:	powerpc-gcc4.6 (powerpc-linux-gcc (GCC) 4.6.3)
Config:	corenet_basic_defconfig (download)
Log:	Download original Possible warnings (1) kernel/printk/printk.c:182:16: warning: 'old' may be used uninitialized in this function [-Wuninitialized] Full Log # git rev-parse -q --verify 81b654c273914704a4bdf580f28d67aaba1094e4^{commit} 81b654c273914704a4bdf580f28d67aaba1094e4 already have revision, skipping fetch # git checkout -q -f -B kisskb 81b654c273914704a4bdf580f28d67aaba1094e4 # git clean -qxdf # < git log -1 # commit 81b654c273914704a4bdf580f28d67aaba1094e4 # 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") # Reviewed-by: Nicholas Piggin <npiggin@gmail.com> # Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> # < /opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux-gcc --version # < git log --format=%s --max-count=1 81b654c273914704a4bdf580f28d67aaba1094e4 # < make -s -j 80 ARCH=powerpc O=/kisskb/build/powerpc-fixes_corenet_basic_defconfig_powerpc CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- corenet_basic_defconfig # make -s -j 80 ARCH=powerpc O=/kisskb/build/powerpc-fixes_corenet_basic_defconfig_powerpc CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- /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] Completed OK # rm -rf /kisskb/build/powerpc-fixes_corenet_basic_defconfig_powerpc # Build took: 0:00:22.596516

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