[PATCH v3 0/2] perf inject intel-PT LBR/brstack synthesis fixes

[Ian Rogers]

An intel-pt trace can be turned into LBR events either in perf script
or perf inject with the --itrace=L option. With perf inject the
generated perf.data file failed to be parsed as the sample events were
out of sync with their perf_event_attr. A range of fixes were
required.

This patch was separated from a large perf script refactor that
highlighted the breakage:
https://lore.kernel.org/lkml/20260425224951.174663-1-irogers@xxxxxxxxxx/

v3:
 - Add missing Fixes: tags on both commits.
 - Refactor perf_event__repipe_attr to avoid in-place modifications on
   read-only mmap buffers, preventing SIGSEGV in file mode and premature
   evsel updates in pipe mode.
 - Use perf_event__synthesize_attr to correctly construct and repipe
   attributes in pipe mode.
 - Replace manual arithmetic in convert_sample_callchain with
   perf_event__sample_event_size to prevent uninitialized memory leaks.
 - Retrieve evsel branch_sample_type dynamically in util/arm-spe.c and
   util/cs-etm.c instead of hardcoding 0, resolving missing hw_idx field
   on synthesized branch stacks.

v2: Response to sashiko fixes for patch 2, Namhyung's acked-by for patch 1.

v1: https://lore.kernel.org/lkml/20260428070328.1880314-1-irogers@xxxxxxxxxx/

Ian Rogers (2):
  perf event: Fix size of synthesized sample with branch stacks
  perf inject: Fix itrace branch stack synthesis

 tools/perf/bench/inject-buildid.c  |   9 +-
 tools/perf/builtin-inject.c        | 141 +++++++++++++++++++++++++----
 tools/perf/tests/dlfilter-test.c   |   8 +-
 tools/perf/tests/sample-parsing.c  |   5 +-
 tools/perf/util/arm-spe.c          |  21 ++++-
 tools/perf/util/cs-etm.c           |  23 +++--
 tools/perf/util/intel-bts.c        |   3 +-
 tools/perf/util/intel-pt.c         |  26 ++++--
 tools/perf/util/synthetic-events.c |  25 +++--
 tools/perf/util/synthetic-events.h |   6 +-
 10 files changed, 216 insertions(+), 51 deletions(-)

-- 
2.54.0.563.g4f69b47b94-goog