# git rev-parse -q --verify f8b2336f15f3bc30e37ce5c052cde5b6319bb6df^{commit} f8b2336f15f3bc30e37ce5c052cde5b6319bb6df already have revision, skipping fetch # git checkout -q -f -B kisskb f8b2336f15f3bc30e37ce5c052cde5b6319bb6df # git clean -qxdf # < git log -1 # commit f8b2336f15f3bc30e37ce5c052cde5b6319bb6df # Author: Michael Ellerman # Date: Wed Feb 22 00:03:31 2023 +1100 # # powerpc: Avoid dead code/data elimination when using recordmcount # # Although powerpc now has objtool mcount support, it's not enabled in all # configurations due to dependencies. # # On those configurations, with some linkers (binutils 2.37 at least), # it's still possible to hit the dreaded "recordmcount bug", eg. errors # such as: # # CC kernel/kexec_file.o # Cannot find symbol for section 10: .text.unlikely. # kernel/kexec_file.o: failed # make[1]: *** [scripts/Makefile.build:287 : kernel/kexec_file.o] Error 1 # # Those errors are much more prevalent when building with # CONFIG_LD_DEAD_CODE_DATA_ELIMINATION, because it places every function # in a separate section. # # CONFIG_LD_DEAD_CODE_DATA_ELIMINATION is marked experimental and is not # enabled in any powerpc defconfigs or by major distros. Although it does # have at least some users on 32-bit where kernel size tends to be more # important. # # Avoid the build errors by blocking CONFIG_LD_DEAD_CODE_DATA_ELIMINATION # when the build is using recordmcount, rather than objtool. In practice # that means for 64-bit big endian builds, or 64-bit clang builds - both # because they lack CONFIG_MPROFILE_KERNEL. # # On 32-bit objtool is always used, so # CONFIG_LD_DEAD_CODE_DATA_ELIMINATION is still available there. # # Signed-off-by: Michael Ellerman # Link: https://lore.kernel.org/r/20230221130331.2714199-1-mpe@ellerman.id.au # < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc --version # < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-ld --version # < git log --format=%s --max-count=1 f8b2336f15f3bc30e37ce5c052cde5b6319bb6df # < make -s -j 160 ARCH=powerpc O=/kisskb/build/powerpc-fixes_44x_bluestone_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- 44x/bluestone_defconfig # < make -s -j 160 ARCH=powerpc O=/kisskb/build/powerpc-fixes_44x_bluestone_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- help # make -s -j 160 ARCH=powerpc O=/kisskb/build/powerpc-fixes_44x_bluestone_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- olddefconfig # make -s -j 160 ARCH=powerpc O=/kisskb/build/powerpc-fixes_44x_bluestone_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- Completed OK # rm -rf /kisskb/build/powerpc-fixes_44x_bluestone_defconfig_powerpc-gcc5 # Build took: 0:00:23.429770