Re: [PATCH v3 00/20] Remove PERF_HAVE_DWARF_REGS

Namhyung Kim
2024-11-07T19:54:35Z

Hi all,

On Wed, Oct 16, 2024 at 05:25:00PM -0700, Ian Rogers wrote:
> These changes are on top of:
> https://lore.kernel.org/lkml/20241017001354.56973-1-irogers@google.com/
>
> Prior to these patches PERF_HAVE_DWARF_REGS indicated the presence of
> dwarf-regs.c in the arch directory. dwarf-regs.c provided upto 4
> functions:
>
> 1) regs_query_register_offset would translate a register name into a
> pt_regs offset and was used by BPF prologues. BPF prologues existed
> for BPF events and support for these was removed many releases ago.
> This code was dead and could be removed.
>
> 2) get_arch_regstr duplicated get_dwarf_regstr and so it could be
> removed. The case for csky was a little more complicated as the ABI
> controlled the string. The callers of get_dwarf_regstr were updated to
> also pass the ELF flags so that on csky the ABI appropriate table
> could be used. As the argument is only used on csky this a no-op for
> everything else.
>
> 3) get_arch_regnum translated a register name back to a dwarf number
> and only existed on x86 where "al", "ax", "eax" and "rax" could all
> mean register 0. This code was moved to util with similar
> machine/flags logic to get_arch_regstr and for consistency with it.
>
> 4) get_powerpc_regs a PowerPC specific function used by annotate that
> should really be in util.
>
> 2 and 3 required the wiring through of the ELF machine and flags in
> callers to get_dwarf_regstr and get_dwarf_regnum. When these values
> weren't dependent on an ELF file a new EM_HOST and EF_HOST were added
> to give the host ELF machine and flags. These 2 #defines got rid of
> the existing separate arch files and #ifdefs.
>
> v3: These files were separated from the rest of the v2 libdw clean up
> in:
> https://lore.kernel.org/lkml/CAP-5=fVZH3L-6y_sxLwSmT8WyMXDMFnuqUksNULdQYJCPNBFYw@mail.gmail.com/
>
> Ian Rogers (20):
> perf bpf-prologue: Remove unused file
> perf dwarf-regs: Remove PERF_HAVE_ARCH_REGS_QUERY_REGISTER_OFFSET
> perf dwarf-regs: Add EM_HOST and EF_HOST defines
> perf disasm: Add e_machine/e_flags to struct arch
> perf dwarf-regs: Pass accurate disassembly machine to get_dwarf_regnum
> perf dwarf-regs: Pass ELF flags to get_dwarf_regstr
> perf dwarf-regs: Move x86 dwarf-regs out of arch
> perf arm64: Remove dwarf-regs.c
> perf arm: Remove dwarf-regs.c
> perf dwarf-regs: Move csky dwarf-regs out of arch
> perf loongarch: Remove dwarf-regs.c
> perf mips: Remove dwarf-regs.c
> perf dwarf-regs: Move powerpc dwarf-regs out of arch
> perf riscv: Remove dwarf-regs.c and add dwarf-regs-table.h
> perf s390: Remove dwarf-regs.c
> perf sh: Remove dwarf-regs.c
> perf sparc: Remove dwarf-regs.c
> perf xtensa: Remove dwarf-regs.c
> perf dwarf-regs: Remove get_arch_regstr code
> perf build: Remove PERF_HAVE_DWARF_REGS

These look all good and I'm about to apply the series.

Masami, do you have any remaining concerns? It'd be nice if you can
give your Reviewed-by.

Thanks,
Namhyug

>
> tools/perf/Makefile.config | 17 +-
> tools/perf/arch/arc/annotate/instructions.c | 2 +
> tools/perf/arch/arm/Makefile | 3 -
> tools/perf/arch/arm/annotate/instructions.c | 2 +
> tools/perf/arch/arm/util/Build | 2 -
> tools/perf/arch/arm/util/dwarf-regs.c | 61 -------
> tools/perf/arch/arm64/Makefile | 4 -
> tools/perf/arch/arm64/annotate/instructions.c | 2 +
> tools/perf/arch/arm64/util/Build | 1 -
> tools/perf/arch/arm64/util/dwarf-regs.c | 92 -----------
> tools/perf/arch/csky/Makefile | 4 -
> tools/perf/arch/csky/annotate/instructions.c | 7 +-
> tools/perf/arch/csky/util/Build | 1 -
> tools/perf/arch/loongarch/Makefile | 4 -
> .../arch/loongarch/annotate/instructions.c | 2 +
> tools/perf/arch/loongarch/util/Build | 1 -
> tools/perf/arch/loongarch/util/dwarf-regs.c | 44 -----
> tools/perf/arch/mips/Makefile | 4 -
> tools/perf/arch/mips/annotate/instructions.c | 2 +
> tools/perf/arch/mips/util/Build | 1 -
> tools/perf/arch/mips/util/dwarf-regs.c | 38 -----
> tools/perf/arch/powerpc/Makefile | 5 -
> .../perf/arch/powerpc/annotate/instructions.c | 2 +
> tools/perf/arch/powerpc/util/Build | 1 -
> tools/perf/arch/powerpc/util/dwarf-regs.c | 153 ------------------
> tools/perf/arch/riscv/Makefile | 5 +-
> .../arch/riscv/include/dwarf-regs-table.h | 42 +++++
> tools/perf/arch/riscv/util/Build | 1 -
> tools/perf/arch/riscv/util/dwarf-regs.c | 72 ---------
> .../perf/arch/riscv64/annotate/instructions.c | 2 +
> tools/perf/arch/s390/Makefile | 4 -
> tools/perf/arch/s390/annotate/instructions.c | 2 +
> tools/perf/arch/s390/util/Build | 1 -
> tools/perf/arch/s390/util/dwarf-regs.c | 43 -----
> tools/perf/arch/sh/Build | 1 -
> tools/perf/arch/sh/Makefile | 4 -
> tools/perf/arch/sh/util/Build | 1 -
> tools/perf/arch/sh/util/dwarf-regs.c | 41 -----
> tools/perf/arch/sparc/Build | 1 -
> tools/perf/arch/sparc/Makefile | 4 -
> tools/perf/arch/sparc/annotate/instructions.c | 2 +
> tools/perf/arch/sparc/util/Build | 1 -
> tools/perf/arch/sparc/util/dwarf-regs.c | 39 -----
> tools/perf/arch/x86/Makefile | 4 -
> tools/perf/arch/x86/annotate/instructions.c | 3 +-
> tools/perf/arch/x86/util/Build | 3 -
> tools/perf/arch/x86/util/dwarf-regs.c | 153 ------------------
> tools/perf/arch/xtensa/Build | 1 -
> tools/perf/arch/xtensa/Makefile | 4 -
> tools/perf/arch/xtensa/util/Build | 1 -
> tools/perf/arch/xtensa/util/dwarf-regs.c | 21 ---
> tools/perf/util/Build | 3 +
> tools/perf/util/annotate.c | 6 +-
> tools/perf/util/bpf-prologue.h | 37 -----
> tools/perf/util/disasm.h | 4 +
> .../dwarf-regs.c => util/dwarf-regs-csky.c} | 19 +--
> tools/perf/util/dwarf-regs-powerpc.c | 61 +++++++
> tools/perf/util/dwarf-regs-x86.c | 50 ++++++
> tools/perf/util/dwarf-regs.c | 38 +++--
> tools/perf/util/include/dwarf-regs.h | 110 ++++++++++---
> tools/perf/util/probe-finder.c | 13 +-
> tools/perf/util/probe-finder.h | 3 +-
> 62 files changed, 328 insertions(+), 927 deletions(-)
> delete mode 100644 tools/perf/arch/arm/util/dwarf-regs.c
> delete mode 100644 tools/perf/arch/arm64/util/dwarf-regs.c
> delete mode 100644 tools/perf/arch/csky/Makefile
> delete mode 100644 tools/perf/arch/loongarch/util/dwarf-regs.c
> delete mode 100644 tools/perf/arch/mips/util/dwarf-regs.c
> delete mode 100644 tools/perf/arch/powerpc/util/dwarf-regs.c
> create mode 100644 tools/perf/arch/riscv/include/dwarf-regs-table.h
> delete mode 100644 tools/perf/arch/riscv/util/dwarf-regs.c
> delete mode 100644 tools/perf/arch/s390/util/dwarf-regs.c
> delete mode 100644 tools/perf/arch/sh/Build
> delete mode 100644 tools/perf/arch/sh/Makefile
> delete mode 100644 tools/perf/arch/sh/util/Build
> delete mode 100644 tools/perf/arch/sh/util/dwarf-regs.c
> delete mode 100644 tools/perf/arch/sparc/Build
> delete mode 100644 tools/perf/arch/sparc/util/Build
> delete mode 100644 tools/perf/arch/sparc/util/dwarf-regs.c
> delete mode 100644 tools/perf/arch/x86/util/dwarf-regs.c
> delete mode 100644 tools/perf/arch/xtensa/Build
> delete mode 100644 tools/perf/arch/xtensa/Makefile
> delete mode 100644 tools/perf/arch/xtensa/util/Build
> delete mode 100644 tools/perf/arch/xtensa/util/dwarf-regs.c
> delete mode 100644 tools/perf/util/bpf-prologue.h
> rename tools/perf/{arch/csky/util/dwarf-regs.c => util/dwarf-regs-csky.c} (74%)
> create mode 100644 tools/perf/util/dwarf-regs-powerpc.c
> create mode 100644 tools/perf/util/dwarf-regs-x86.c
>
> --
> 2.47.0.105.g07ac214952-goog
>