# git rev-parse -q --verify b49e578b9314db051da0ad72bba24094193f9bd0^{commit}
b49e578b9314db051da0ad72bba24094193f9bd0
already have revision, skipping fetch
# git checkout -q -f -B kisskb b49e578b9314db051da0ad72bba24094193f9bd0
# git clean -qxdf
# < git log -1
# commit b49e578b9314db051da0ad72bba24094193f9bd0
# Author: Christophe Leroy <christophe.leroy@csgroup.eu>
# Date:   Wed Jul 12 23:45:02 2023 +1000
# 
#     Revert "powerpc/bug: Provide better flexibility to WARN_ON/__WARN_FLAGS() with asm goto"
#     
#     This partly reverts commit 1e688dd2a3d6759d416616ff07afc4bb836c4213.
#     
#     That commit aimed at optimising the code around generation of
#     WARN_ON/BUG_ON but this leads to a lot of dead code erroneously
#     generated by GCC.
#     
#     That dead code becomes a problem when we start using objtool validation
#     because objtool will abort validation with a warning as soon as it
#     detects unreachable code. This is because unreachable code might
#     be the indication that objtool doesn't properly decode object text.
#     
#          text          data     bss     dec     hex filename
#       9551585       3627834  224376 13403795         cc8693 vmlinux.before
#       9535281       3628358  224376 13388015         cc48ef vmlinux.after
#     
#     Once this change is reverted, in a standard configuration (pmac32 +
#     function tracer) the text is reduced by 16k which is around 1.7%
#     
#     We already had problem with it when starting to use objtool on powerpc
#     as a replacement for recordmcount, see commit 93e3f45a2631 ("powerpc:
#     Fix __WARN_FLAGS() for use with Objtool")
#     
#     There is also a problem with at least GCC 12, on ppc64_defconfig +
#     CONFIG_CC_OPTIMIZE_FOR_SIZE=y + CONFIG_DEBUG_SECTION_MISMATCH=y :
#     
#         LD      .tmp_vmlinux.kallsyms1
#       powerpc64-linux-ld: net/ipv4/tcp_input.o:(__ex_table+0xc4): undefined reference to `.L2136'
#       make[2]: *** [scripts/Makefile.vmlinux:36: vmlinux] Error 1
#       make[1]: *** [/home/chleroy/linux-powerpc/Makefile:1238: vmlinux] Error 2
#     
#     Taking into account that other problems are encountered with that
#     'asm goto' in WARN_ON(), including build failures, keeping that
#     change is not worth it allthough it is primarily a compiler bug.
#     
#     Revert it for now.
#     
#     mpe: Retain EMIT_WARN_ENTRY as a synonym for EMIT_BUG_ENTRY to reduce
#     churn, as there are now nearly as many uses of EMIT_WARN_ENTRY as
#     EMIT_BUG_ENTRY.
#     
#     Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
#     Acked-by: Naveen N Rao <naveen@kernel.org>
#     Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
#     Link: https://msgid.link/20230712134552.534955-1-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 b49e578b9314db051da0ad72bba24094193f9bd0
# make -s -j 160 ARCH=powerpc O=/kisskb/build/powerpc-fixes_corenet64_smp_defconfig+KVM_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  corenet64_smp_defconfig
Using /kisskb/src/arch/powerpc/configs/corenet_base.config as base
Merging /kisskb/src/arch/powerpc/configs/85xx-64bit.config
Merging /kisskb/src/arch/powerpc/configs/85xx-smp.config
Merging /kisskb/src/arch/powerpc/configs/altivec.config
Merging /kisskb/src/arch/powerpc/configs/85xx-hw.config
Merging /kisskb/src/arch/powerpc/configs/fsl-emb-nonhw.config
Merging /kisskb/src/arch/powerpc/configs/dpaa.config
#
# merged configuration written to .config (needs make)
#
# Added to kconfig CONFIG_KVM_E500MC=y
# Added to kconfig CONFIG_VIRTUALIZATION=y
# Added to kconfig CONFIG_KVM_MPIC=y
# < make -s -j 160 ARCH=powerpc O=/kisskb/build/powerpc-fixes_corenet64_smp_defconfig+KVM_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_corenet64_smp_defconfig+KVM_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  olddefconfig
.config:4533:warning: override: reassigning to symbol VIRTUALIZATION
# make -s -j 160 ARCH=powerpc O=/kisskb/build/powerpc-fixes_corenet64_smp_defconfig+KVM_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_corenet64_smp_defconfig+KVM_powerpc-gcc5
# Build took: 0:02:27.695041