# git rev-parse -q --verify e893cdee5343060f224768d7657829c2da2e2848^{commit} e893cdee5343060f224768d7657829c2da2e2848 already have revision, skipping fetch # git checkout -q -f -B kisskb e893cdee5343060f224768d7657829c2da2e2848 # git clean -qxdf # < git log -1 # commit e893cdee5343060f224768d7657829c2da2e2848 # Author: Nathan Chancellor # Date: Wed May 11 11:50:01 2022 -0700 # # powerpc/vdso: Link with ld.lld when requested # # The PowerPC vDSO uses $(CC) to link, which differs from the rest of the # kernel, which uses $(LD) directly. As a result, the default linker of # the compiler is used, which may differ from the linker requested by the # builder. For example: # # $ make ARCH=powerpc LLVM=1 mrproper defconfig arch/powerpc/kernel/vdso/ # ... # # $ llvm-readelf -p .comment arch/powerpc/kernel/vdso/vdso{32,64}.so.dbg # # File: arch/powerpc/kernel/vdso/vdso32.so.dbg # String dump of section '.comment': # [ 0] clang version 14.0.0 (Fedora 14.0.0-1.fc37) # # File: arch/powerpc/kernel/vdso/vdso64.so.dbg # String dump of section '.comment': # [ 0] clang version 14.0.0 (Fedora 14.0.0-1.fc37) # # LLVM=1 sets LD=ld.lld but ld.lld is not used to link the vDSO; GNU ld is # because "ld" is the default linker for clang on most Linux platforms. # # This is a problem for Clang's Link Time Optimization as implemented in # the kernel because use of GNU ld with LTO requires the LLVMgold plugin, # which is not technically supported for ld.bfd per # https://llvm.org/docs/GoldPlugin.html. Furthermore, if LLVMgold.so is # missing from a user's system, the build will fail, even though LTO as it # is implemented in the kernel requires ld.lld to avoid this dependency in # the first place. # # Ultimately, the PowerPC vDSO should be converted to compiling and # linking with $(CC) and $(LD) respectively but there were issues last # time this was tried, potentially due to older but supported tool # versions. To avoid regressing GCC + binutils, use the compiler option # '-fuse-ld', which tells the compiler which linker to use when it is # invoked as both the compiler and linker. Use '-fuse-ld=lld' when # LD=ld.lld has been specified (CONFIG_LD_IS_LLD) so that the vDSO is # linked with the same linker as the rest of the kernel. # # $ llvm-readelf -p .comment arch/powerpc/kernel/vdso/vdso{32,64}.so.dbg # # File: arch/powerpc/kernel/vdso/vdso32.so.dbg # String dump of section '.comment': # [ 0] Linker: LLD 14.0.0 # [ 14] clang version 14.0.0 (Fedora 14.0.0-1.fc37) # # File: arch/powerpc/kernel/vdso/vdso64.so.dbg # String dump of section '.comment': # [ 0] Linker: LLD 14.0.0 # [ 14] clang version 14.0.0 (Fedora 14.0.0-1.fc37) # # LD can be a full path to ld.lld, which will not be handled properly by # '-fuse-ld=lld' if the full path to ld.lld is outside of the compiler's # search path. '-fuse-ld' can take a path to the linker but it is # deprecated in clang 12.0.0; '--ld-path' is preferred for this scenario. # # Use '--ld-path' if it is supported, as it will handle a full path or # just 'ld.lld' properly. See the LLVM commit below for the full details # of '--ld-path'. # # Signed-off-by: Nathan Chancellor # Tested-by: Alexey Kardashevskiy # Reviewed-by: Nick Desaulniers # Reviewed-by: Alexey Kardashevskiy # Signed-off-by: Michael Ellerman # Link: https://github.com/ClangBuiltLinux/linux/issues/774 # Link: https://github.com/llvm/llvm-project/commit/1bc5c84710a8c73ef21295e63c19d10a8c71f2f5 # Link: https://lore.kernel.org/r/20220511185001.3269404-3-nathan@kernel.org # < /opt/cross/kisskb/korg/gcc-11.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc --version # < /opt/cross/kisskb/korg/gcc-11.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-ld --version # < git log --format=%s --max-count=1 e893cdee5343060f224768d7657829c2da2e2848 # < make -s -j 32 ARCH=powerpc O=/kisskb/build/powerpc-next_skiroot_defconfig_powerpc-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux- skiroot_defconfig # < make -s -j 32 ARCH=powerpc O=/kisskb/build/powerpc-next_skiroot_defconfig_powerpc-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux- help # make -s -j 32 ARCH=powerpc O=/kisskb/build/powerpc-next_skiroot_defconfig_powerpc-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux- olddefconfig # make -s -j 32 ARCH=powerpc O=/kisskb/build/powerpc-next_skiroot_defconfig_powerpc-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux- In file included from /kisskb/src/include/linux/byteorder/little_endian.h:5, from /kisskb/src/arch/powerpc/include/uapi/asm/byteorder.h:12, from /kisskb/src/include/asm-generic/bitops/le.h:6, from /kisskb/src/arch/powerpc/include/asm/bitops.h:336, from /kisskb/src/include/linux/bitops.h:33, from /kisskb/src/include/linux/kernel.h:22, from /kisskb/src/drivers/scsi/mpt3sas/mpt3sas_base.c:46: /kisskb/src/drivers/scsi/mpt3sas/mpt3sas_base.c: In function '_base_make_ioc_operational': /kisskb/src/drivers/scsi/mpt3sas/mpt3sas_base.c:5396:40: warning: array subscript 'Mpi2SasIOUnitPage1_t {aka struct _MPI2_CONFIG_PAGE_SASIOUNIT_1}[0]' is partly outside array bounds of 'unsigned char[20]' [-Warray-bounds] 5396 | (le16_to_cpu(sas_iounit_pg1->SASWideMaxQueueDepth)) ? /kisskb/src/include/uapi/linux/byteorder/little_endian.h:37:51: note: in definition of macro '__le16_to_cpu' 37 | #define __le16_to_cpu(x) ((__force __u16)(__le16)(x)) | ^ /kisskb/src/drivers/scsi/mpt3sas/mpt3sas_base.c:5396:14: note: in expansion of macro 'le16_to_cpu' 5396 | (le16_to_cpu(sas_iounit_pg1->SASWideMaxQueueDepth)) ? | ^~~~~~~~~~~ /kisskb/src/drivers/scsi/mpt3sas/mpt3sas_base.c:5382:26: note: referencing an object of size 20 allocated by 'kzalloc' 5382 | sas_iounit_pg1 = kzalloc(sz, GFP_KERNEL); | ^~~~~~~~~~~~~~~~~~~~~~~ In file included from /kisskb/src/include/linux/byteorder/little_endian.h:5, from /kisskb/src/arch/powerpc/include/uapi/asm/byteorder.h:12, from /kisskb/src/include/asm-generic/bitops/le.h:6, from /kisskb/src/arch/powerpc/include/asm/bitops.h:336, from /kisskb/src/include/linux/bitops.h:33, from /kisskb/src/include/linux/kernel.h:22, from /kisskb/src/drivers/scsi/mpt3sas/mpt3sas_base.c:46: /kisskb/src/drivers/scsi/mpt3sas/mpt3sas_base.c:5400:40: warning: array subscript 'Mpi2SasIOUnitPage1_t {aka struct _MPI2_CONFIG_PAGE_SASIOUNIT_1}[0]' is partly outside array bounds of 'unsigned char[20]' [-Warray-bounds] 5400 | (le16_to_cpu(sas_iounit_pg1->SASNarrowMaxQueueDepth)) ? /kisskb/src/include/uapi/linux/byteorder/little_endian.h:37:51: note: in definition of macro '__le16_to_cpu' 37 | #define __le16_to_cpu(x) ((__force __u16)(__le16)(x)) | ^ /kisskb/src/drivers/scsi/mpt3sas/mpt3sas_base.c:5400:14: note: in expansion of macro 'le16_to_cpu' 5400 | (le16_to_cpu(sas_iounit_pg1->SASNarrowMaxQueueDepth)) ? | ^~~~~~~~~~~ /kisskb/src/drivers/scsi/mpt3sas/mpt3sas_base.c:5382:26: note: referencing an object of size 20 allocated by 'kzalloc' 5382 | sas_iounit_pg1 = kzalloc(sz, GFP_KERNEL); | ^~~~~~~~~~~~~~~~~~~~~~~ /kisskb/src/drivers/scsi/mpt3sas/mpt3sas_base.c:5403:43: warning: array subscript 'Mpi2SasIOUnitPage1_t {aka struct _MPI2_CONFIG_PAGE_SASIOUNIT_1}[0]' is partly outside array bounds of 'unsigned char[20]' [-Warray-bounds] 5403 | ioc->max_sata_qd = (sas_iounit_pg1->SATAMaxQDepth) ? | ~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~ /kisskb/src/drivers/scsi/mpt3sas/mpt3sas_base.c:5382:26: note: referencing an object of size 20 allocated by 'kzalloc' 5382 | sas_iounit_pg1 = kzalloc(sz, GFP_KERNEL); | ^~~~~~~~~~~~~~~~~~~~~~~ Completed OK # rm -rf /kisskb/build/powerpc-next_skiroot_defconfig_powerpc-gcc11 # Build took: 0:01:32.666106