kernel/linux.git/arch/powerpc/Makefile, branch v6.6.131

powerpc: Adjust adding stack protector flags to KBUILD_CLAGS for clang

2024-12-09T09:33:09+00:00

commit bee08a9e6ab03caf14481d97b35a258400ffab8f upstream. After fixing the HAVE_STACKPROTECTER checks for clang's in-progress per-task stack protector support [1], the build fails during prepare0 because '-mstack-protector-guard-offset' has not been added to KBUILD_CFLAGS yet but the other '-mstack-protector-guard' flags have. clang: error: '-mstack-protector-guard=tls' is used without '-mstack-protector-guard-offset', and there is no default clang: error: '-mstack-protector-guard=tls' is used without '-mstack-protector-guard-offset', and there is no default make[4]: *** [scripts/Makefile.build:229: scripts/mod/empty.o] Error 1 make[4]: *** [scripts/Makefile.build:102: scripts/mod/devicetable-offsets.s] Error 1 Mirror other architectures and add all '-mstack-protector-guard' flags to KBUILD_CFLAGS atomically during stack_protector_prepare, which resolves the issue and allows clang's implementation to fully work with the kernel. Cc: stable@vger.kernel.org # 6.1+ Link: https://github.com/llvm/llvm-project/pull/110928 [1] Reviewed-by: Keith Packard Tested-by: Keith Packard Signed-off-by: Nathan Chancellor Signed-off-by: Michael Ellerman Link: https://patch.msgid.link/20241009-powerpc-fix-stackprotector-test-clang-v2-2-12fb86b31857@kernel.org Signed-off-by: Greg Kroah-Hartman

powerpc/64s: Move CPU -mtune options into Kconfig

2023-08-24T22:39:29+00:00

Currently the -mtune options are set in the Makefile, depending on what the compiler supports. One downside of doing it that way is that the chosen -mtune option is not recorded in the .config. Another downside is that if there's ever a need to do more complicated logic to calculate the correct option, that gets messy in the Makefile. So move the determination of which -mtune option to use into Kconfig logic. Signed-off-by: Michael Ellerman Link: https://msgid.link/20230329234308.2215833-1-mpe@ellerman.id.au

powerpc/ftrace: Add support for -fpatchable-function-entry

2023-08-21T14:09:06+00:00

GCC v13.1 updated support for -fpatchable-function-entry on ppc64le to emit nops after the local entry point, rather than before it. This allows us to use this in the kernel for ftrace purposes. A new script is added under arch/powerpc/tools/ to help detect if nops are emitted after the function local entry point, or before the global entry point. With -fpatchable-function-entry, we no longer have the profiling instructions generated at function entry, so we only need to validate the presence of two nops at the ftrace location in ftrace_init_nop(). We patch the preceding instruction with 'mflr r0' to match the -mprofile-kernel ABI for subsequent ftrace use. This changes the profiling instructions used on ppc32. The default -pg option emits an additional 'stw' instruction after 'mflr r0' and before the branch to _mcount 'bl _mcount'. This is very similar to the original -mprofile-kernel implementation on ppc64le, where an additional 'std' instruction was used to save LR to its save location in the caller's stackframe. Subsequently, this additional store was removed in later compiler versions for performance reasons. The same reasons apply for ppc32 so we only patch in a 'mflr r0'. Signed-off-by: Naveen N Rao Reviewed-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://msgid.link/68586d22981a2c3bb45f27a2b621173d10a7d092.1687166935.git.naveen@kernel.org

powerpc: remove checks for binutils older than 2.25

2023-06-27T06:59:29+00:00

Commit e4412739472b ("Documentation: raise minimum supported version of binutils to 2.25") allows us to remove the checks for old binutils. There is no more user for ld-ifversion. Remove it as well. Signed-off-by: Masahiro Yamada Reviewed-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://msgid.link/20230119082250.151485-1-masahiroy@kernel.org

powerpc: Fail build if using recordmcount with binutils v2.37

2023-06-27T06:19:06+00:00

binutils v2.37 drops unused section symbols, which prevents recordmcount from capturing mcount locations in sections that have no non-weak symbols. This results in a build failure with a message such as: Cannot find symbol for section 12: .text.perf_callchain_kernel. kernel/events/callchain.o: failed The change to binutils was reverted for v2.38, so this behavior is specific to binutils v2.37: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=c09c8b42021180eee9495bd50d8b35e683d3901b Objtool is able to cope with such sections, so this issue is specific to recordmcount. Fail the build and print a warning if binutils v2.37 is detected and if we are using recordmcount. Cc: stable@vger.kernel.org Suggested-by: Joel Stanley Signed-off-by: Naveen N Rao Signed-off-by: Michael Ellerman Link: https://msgid.link/20230530061436.56925-1-naveen@kernel.org

powerpc/build: Remove -pipe from compilation flags

2023-06-14T02:46:42+00:00

x86 removed -pipe in commit 437e88ab8f9e2 ("x86/build: Remove -pipe from KBUILD_CFLAGS") and the newer arm64 and riscv seem to have never used it, so that seems to be the way the world's going. Compile performance building defconfig on a POWER10 PowerNV system was in the noise after 10 builds each. No point in adding options unless they help something, so remove it. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://msgid.link/20230606064830.184083-1-npiggin@gmail.com

powerpc/configs: Make pseries_defconfig an alias for ppc64le_guest

2023-04-21T06:16:25+00:00

Rather than trying to keep multiple configs up to date, make pseries_defconfig an alias for ppc64le_guest_defconfig. NOTE, pseries_defconfig was a big endian config, but this commit switches it to little endian. Almost all distros are ppc64le these days, so little endian is much more likely to be what a user wants when they build for "pseries". For an actual big endian guest, use ppc64_guest_defconfig. Signed-off-by: Michael Ellerman Link: https://msgid.link/20230414132415.821564-32-mpe@ellerman.id.au

powerpc/configs: Make pseries_le an alias for ppc64le_guest

2023-04-21T06:16:25+00:00

Rather than trying to keep multiple configs up to date, make pseries_le_defconfig an alias for ppc64le_guest_defconfig. ppc64le_guest_defconfig should work in all cases that pseries_le_defconfig currently does, but if not we can update it. Move pseries_le_defconfig down in the Makefile, so it appears after ppc64le_guest_defconfig in the help output. Signed-off-by: Michael Ellerman Link: https://msgid.link/20230414132415.821564-31-mpe@ellerman.id.au

powerpc/configs: Incorporate generic kvm_guest.config into guest configs

2023-04-21T06:16:25+00:00

Incorporate the generic kvm_guest.config into the powerpc guest configs, ppc64[le]_guest_defconfig. This brings in some useful options, in particular 9P support, and also means future additions to the generic file will be automatically picked up by the powerpc configs. Signed-off-by: Michael Ellerman Link: https://msgid.link/20230414132415.821564-30-mpe@ellerman.id.au

powerpc/Makefile: Add generated defconfigs to help output

2023-04-21T06:16:13+00:00

Currently none of the generated defconfigs appear in the help output, because the help text discovers defconfigs by looking for actual files named "*_defconfig". Collect the generated defconfig names into a variable and then print those out in archhelp. Output looks like eg: pseries_le_defconfig - Build for pseries_le ppc64le_defconfig - Build for ppc64le ppc64le_guest_defconfig - Build for ppc64le_guest ... ppc64_randconfig - Build for ppc64_randconfig adder875_defconfig - Build for adder875 amigaone_defconfig - Build for amigaone Signed-off-by: Michael Ellerman [mpe: Fix PHONY bug which broke in-tree build, thanks rmclure] Link: https://msgid.link/20230329072334.2023357-2-mpe@ellerman.id.au