[PATCH v3 00/20] Remove PERF_HAVE_DWARF_REGS

Ian Rogers
2024-10-17T00:53:10Z

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

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