# 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 # 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 # Signed-off-by: Michael Ellerman # < /opt/cross/kisskb/gcc-4.6.3-nolibc/sh4-linux/bin/sh4-linux-gcc --version # < git log --format=%s --max-count=1 81b654c273914704a4bdf580f28d67aaba1094e4 # < make -s -j 48 ARCH=sh O=/kisskb/build/powerpc-fixes_sh-defconfig_sh4 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/sh4-linux/bin/sh4-linux- defconfig # make -s -j 48 ARCH=sh O=/kisskb/build/powerpc-fixes_sh-defconfig_sh4 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/sh4-linux/bin/sh4-linux- Generating include/generated/machtypes.h :1317:2: warning: #warning syscall pkey_mprotect not implemented [-Wcpp] :1320:2: warning: #warning syscall pkey_alloc not implemented [-Wcpp] :1323:2: warning: #warning syscall pkey_free not implemented [-Wcpp] :1326:2: warning: #warning syscall statx not implemented [-Wcpp] /kisskb/src/arch/sh/kernel/cpu/sh4/../sh3/../../entry-common.S: Assembler messages: /kisskb/src/arch/sh/kernel/cpu/sh4/../sh3/../../entry-common.S:389: Warning: overflow in branch to syscall_exit_work; converted into longer instruction sequence /kisskb/src/arch/sh/kernel/cpu/sh4/../sh3/../../entry-common.S:392: Warning: overflow in branch to syscall_exit_work; converted into longer instruction sequence /kisskb/src/fs/mpage.c: In function 'do_mpage_readpage': /kisskb/src/fs/mpage.c:316:1: warning: the frame size of 1088 bytes is larger than 1024 bytes [-Wframe-larger-than=] /kisskb/src/fs/mpage.c: In function '__mpage_writepage': /kisskb/src/fs/mpage.c:676:1: warning: the frame size of 1152 bytes is larger than 1024 bytes [-Wframe-larger-than=] /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/rcu/srcutree.c: In function 'init_srcu_struct_fields': /kisskb/src/kernel/rcu/srcutree.c:146:32: warning: 'levelspread[]' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/kernel/rcu/srcutree.c:94:6: note: 'levelspread[]' was declared here /kisskb/src/mm/vmstat.c: In function 'sysctl_vm_numa_stat_handler': /kisskb/src/mm/vmstat.c:89:5: warning: 'oldval' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/kernel/cgroup/cgroup-v1.c: In function 'cgroup1_mount': /kisskb/src/kernel/cgroup/cgroup-v1.c:1268:20: warning: 'root' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/sh/clk/cpg.c: In function 'r8': /kisskb/src/drivers/sh/clk/cpg.c:41:2: warning: passing argument 1 of 'ioread8' discards 'const' qualifier from pointer target type [enabled by default] /kisskb/src/include/asm-generic/iomap.h:29:21: note: expected 'void *' but argument is of type 'const void *' /kisskb/src/drivers/sh/clk/cpg.c: In function 'r16': /kisskb/src/drivers/sh/clk/cpg.c:46:2: warning: passing argument 1 of 'ioread16' discards 'const' qualifier from pointer target type [enabled by default] /kisskb/src/include/asm-generic/iomap.h:30:21: note: expected 'void *' but argument is of type 'const void *' /kisskb/src/drivers/sh/clk/cpg.c: In function 'r32': /kisskb/src/drivers/sh/clk/cpg.c:51:2: warning: passing argument 1 of 'ioread32' discards 'const' qualifier from pointer target type [enabled by default] /kisskb/src/include/asm-generic/iomap.h:32:21: note: expected 'void *' but argument is of type 'const void *' /kisskb/src/drivers/base/regmap/regmap.c: In function 'regmap_raw_read': /kisskb/src/drivers/base/regmap/regmap.c:2497:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/base/regmap/regmap.c: In function '_regmap_raw_write': /kisskb/src/drivers/base/regmap/regmap.c:1819:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/mm/hugetlb.c: In function 'alloc_pool_huge_page': /kisskb/src/mm/hugetlb.c:1433:5: warning: 'page' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/ext4/readpage.c: In function 'ext4_mpage_readpages': /kisskb/src/fs/ext4/readpage.c:294:1: warning: the frame size of 1200 bytes is larger than 1024 bytes [-Wframe-larger-than=] Kernel: arch/sh/boot/zImage is ready Completed OK # rm -rf /kisskb/build/powerpc-fixes_sh-defconfig_sh4 # Build took: 0:00:40.953110