[v1,0/6] perf: arm64: Support for Dwarf unwinding through SVE functions

Message

James Clark May 9, 2022, 2:42 p.m. UTC

When SVE registers are pushed onto the stack the VG register is required to
unwind because the stack offsets would vary by the SVE register width at the
time when the sample was taken.

The first two patches add support for sampling the VG register to the kernel and
the docs. The remaining patches add the support to userspace perf.

A small change is also required to libunwind or libdw depending on which
unwinder is used, and these will be published later. Without these changes Perf
continues to work with both libraries, although the VG register is still not
used for unwinding. 

James Clark (6):
  perf: arm64: Add SVE vector granule register to user regs
  arm64/sve: Add Perf extensions documentation
  perf tools: arm64: Copy perf_regs.h from the kernel
  perf tools: Use dynamic register set for Dwarf unwind
  perf tools: arm64: Decouple Libunwind register names from Perf
  perf tools: arm64: Add support for VG register

 Documentation/arm64/sve.rst                   | 20 +++++
 arch/arm64/include/uapi/asm/perf_regs.h       |  7 +-
 arch/arm64/kernel/perf_regs.c                 | 30 +++++++-
 drivers/perf/arm_pmu.c                        |  2 +-
 tools/arch/arm64/include/uapi/asm/perf_regs.h |  7 +-
 tools/perf/arch/arm64/util/perf_regs.c        | 34 +++++++++
 tools/perf/arch/arm64/util/unwind-libunwind.c | 73 +------------------
 tools/perf/util/evsel.c                       |  2 +-
 tools/perf/util/perf_regs.c                   |  2 +
 9 files changed, 100 insertions(+), 77 deletions(-)