[PATCH v5 0/9] [PATCH v5 0/9] perf DWARF: Fix libdw API contract violations and crashes

[Ian Rogers <irogers@google.com>]

This patch series addresses a number of DWARF/libdw error-handling
bugs and contract violations, preventing several real Userspace
segmentation faults and memory/FD leaks.

In v5, the series has been extensively restructured and polished based on 
comprehensive review feedback on v4, focusing on history granularity, 
bisectability, and defensive styling:

 - **Commit Splitting for Review Granularity**: Split the previously large 
     libdw contract fix patch into 4 granular commits to cleanly isolate 
     independent improvements: introducing clear_frames refactoring, fixing 
     ORDER_CALLER parent update corruption, adding line 0 support, and 
     consolidating core contract/leak cleanups.
 
 - **Bisectability & Correctness Hardening**: 
     - Fixed an unused variable compilation failure (-Werror) in the split 
       history to guarantee perfect git bisectability.
     - Fixed a line 0 fallback regression to ensure that if an optional call 
       line is missing but the call file is valid, we fallback to line 0 
       to preserve the filename rather than discarding the caller info entirely.

 - **Style & Robustness Polish**:
     - Standardized all newly introduced C++ style (//) comments to 
       preferred C style (/* ... */) comments.
     - Implemented explicit safe string duplication style fix in annotate-data.
     - Corrected CU DIE propagation context inside probe-finder.
     - Enhanced the Patch 2 commit message to explicitly detail the removal 
       of strict optional attribute aborts (decf) to clarify review queries.

 - **Tags Collected**: Integrated Acked-by tags from Namhyung Kim for Patch 1 
     and Patch 9.

v5:
 - Restructured series from 6 to 9 patches by splitting the libdw commit.
 - Fixed compilation bisectability and DWARF line 0 filename preservation regressions.
 - Standardized comment styles and applied safe duplication formatting fixes.
 - Updated commit messages with detailed optional attribute justifications.

v4:
 - Localized and squashed robust error handling, memory/FD cleanup
   paths, and safe DWARF printing.
https://lore.kernel.org/linux-perf-users/20260503171032.1559338-1-irogers@google.com/

v3:
 - Minor formatting fixes.
https://lore.kernel.org/linux-perf-users/20260503003552.1063540-1-irogers@google.com/

v2:
https://lore.kernel.org/lkml/20260502155656.478642-1-irogers@google.com/

v1:
https://lore.kernel.org/linux-perf-users/20260502064839.282422-1-irogers@google.com/

Ian Rogers (9):
  perf dwarf-aux: Fix libdw segmentation fault in cu_walk_functions_at
  perf dwarf-aux: Fix libdw API contract violations
  perf srcline: Introduce inline_node__clear_frames()
  perf libdw: Fix callchain parent update in ORDER_CALLER mode
  perf libdw: Support DWARF line 0 in inline list
  perf libdw: Fix libdw API contract violations and memory leaks
  perf probe-finder: Fix libdw API contract violations
  perf annotate-data: Fix libdw API contract violations
  perf debuginfo: Fix libdw API contract violations

 tools/perf/util/annotate-data.c |  27 +++++----
 tools/perf/util/debuginfo.c     |   9 ++-
 tools/perf/util/dwarf-aux.c     |  39 ++++++------
 tools/perf/util/dwarf-aux.h     |   5 ++
 tools/perf/util/libdw.c         |  72 +++++++++++++++++-----
 tools/perf/util/probe-finder.c  | 102 ++++++++++++++++++++------------
 tools/perf/util/srcline.c       |   9 ++-
 tools/perf/util/srcline.h       |   1 +
 8 files changed, 179 insertions(+), 85 deletions(-)

-- 
2.54.0.545.g6539524ca2-goog