| Message ID | 20230505071850.228734-1-npiggin@gmail.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | powerpc/64: ELFv2 conversion | expand |
Le 05/05/2023 à 09:18, Nicholas Piggin a écrit : > This series has the steps to remove ELFv1 from the kernel build. > Patch 1 is a build fix, 2 defaults everything to ELFv2, 3 is > really a separate issue that concerns userspace. 4 removes v1 > support. I see CONFIG_MPROFILE_KERNEL is restricted to LITTLE_ENDIAN. Is that correct ? Don't we have mprofile_kernel as well on BIG ENDIAN once switched to ABI v2 ? If so, can we drop the -pg based profiling completely, or is CLANG still not supporting mprofile_kernel ? Christophe > > Would like to try getting patch 1 in as a fix, then 2,3 merged in > the next merge window. > > Thanks, > Nick > > Nicholas Piggin (4): > powerpc/64: Force ELFv2 when building with LLVM linker > powerpc/64: Make ELFv2 the default for big-endian builds > powerpc/64s: Remove support for ELFv1 little endian userspace > powerpc/64: Remove support for kernel's built with ELFv1 ABI > > arch/powerpc/Kconfig | 21 ------ > arch/powerpc/Makefile | 15 +---- > arch/powerpc/boot/Makefile | 4 +- > arch/powerpc/include/asm/code-patching.h | 36 ++-------- > arch/powerpc/include/asm/elf.h | 6 ++ > arch/powerpc/include/asm/kfence.h | 4 -- > arch/powerpc/include/asm/linkage.h | 9 --- > arch/powerpc/include/asm/module.h | 3 - > arch/powerpc/include/asm/ppc_asm.h | 38 +---------- > arch/powerpc/include/asm/ptrace.h | 17 +---- > arch/powerpc/include/asm/sections.h | 4 -- > arch/powerpc/include/asm/thread_info.h | 6 +- > arch/powerpc/kernel/exceptions-64s.S | 2 +- > arch/powerpc/kernel/fadump.c | 6 +- > arch/powerpc/kernel/head_64.S | 5 +- > arch/powerpc/kernel/interrupt_64.S | 4 -- > arch/powerpc/kernel/kprobes.c | 39 +---------- > arch/powerpc/kernel/misc_64.S | 4 -- > arch/powerpc/kernel/module.c | 8 --- > arch/powerpc/kernel/module_64.c | 84 ++++-------------------- > arch/powerpc/kernel/trace/ftrace.c | 10 --- > arch/powerpc/kernel/vdso/Makefile | 2 +- > arch/powerpc/kernel/vdso/gettimeofday.S | 2 +- > arch/powerpc/kernel/vmlinux.lds.S | 8 --- > arch/powerpc/kvm/book3s_hv_rmhandlers.S | 36 +++++----- > arch/powerpc/kvm/book3s_interrupts.S | 14 ++-- > arch/powerpc/kvm/book3s_rmhandlers.S | 12 +--- > arch/powerpc/net/bpf_jit.h | 6 -- > arch/powerpc/net/bpf_jit_comp.c | 14 ++-- > arch/powerpc/net/bpf_jit_comp64.c | 13 ++-- > arch/powerpc/platforms/Kconfig.cputype | 6 -- > drivers/crypto/vmx/Makefile | 4 -- > kernel/extable.c | 2 +- > kernel/trace/ftrace.c | 12 ---- > 34 files changed, 79 insertions(+), 377 deletions(-) >
Christophe Leroy <christophe.leroy@csgroup.eu> writes: > Le 05/05/2023 à 09:18, Nicholas Piggin a écrit : >> This series has the steps to remove ELFv1 from the kernel build. >> Patch 1 is a build fix, 2 defaults everything to ELFv2, 3 is >> really a separate issue that concerns userspace. 4 removes v1 >> support. > > I see CONFIG_MPROFILE_KERNEL is restricted to LITTLE_ENDIAN. Is that > correct ? Don't we have mprofile_kernel as well on BIG ENDIAN once > switched to ABI v2 ? If so, can we drop the -pg based profiling > completely, or is CLANG still not supporting mprofile_kernel ? Clang does not support -mprofile-kernel. AIUI they would like us to switch to -fpatchable-function-entry which could then be supported on GCC & clang. That would be a nice cleanup but also a bunch of work that no one has found time to do. https://github.com/linuxppc/issues/issues/447 https://github.com/llvm/llvm-project/issues/57031 So for now we need to keep the -pg based version. cheers
Michael Ellerman wrote: > Christophe Leroy <christophe.leroy@csgroup.eu> writes: >> Le 05/05/2023 à 09:18, Nicholas Piggin a écrit : >>> This series has the steps to remove ELFv1 from the kernel build. >>> Patch 1 is a build fix, 2 defaults everything to ELFv2, 3 is >>> really a separate issue that concerns userspace. 4 removes v1 >>> support. Super glad to see this! >> >> I see CONFIG_MPROFILE_KERNEL is restricted to LITTLE_ENDIAN. Is that >> correct ? Don't we have mprofile_kernel as well on BIG ENDIAN once >> switched to ABI v2 ? If so, can we drop the -pg based profiling >> completely, or is CLANG still not supporting mprofile_kernel ? > > Clang does not support -mprofile-kernel. > > AIUI they would like us to switch to -fpatchable-function-entry which > could then be supported on GCC & clang. > > That would be a nice cleanup but also a bunch of work that no one has > found time to do. > > https://github.com/linuxppc/issues/issues/447 > https://github.com/llvm/llvm-project/issues/57031 GCC's support for -fpatchable-function-entry needed fixes for ABIv2, which have landed in the recent v13.1 release. I am looking into adding support for that. > > > So for now we need to keep the -pg based version. Indeed, but removing elf v1 support does help cleaning up and simplifying some of the tracing code. Much of the -pg code is already separate, so it should be easy to drop that once clang picks up support for -fpatchable-function-entry. - Naveen