[PATCH v4 00/17] tools/perf: Adopt kernel compiler-context-analysis.h annotations

[Ian Rogers]

The perf tool previously added Clang thread-safety annotations in
tools/perf/util/mutex.h (GUARDED_BY, LOCKABLE, EXCLUSIVE_LOCK_FUNCTION,
UNLOCK_FUNCTION, etc.). Since then, the Linux kernel has adopted a
unified set of static context analysis macros and attributes in
include/linux/compiler-context-analysis.h (context_lock_struct,
__guarded_by, __acquires, __releases, __must_hold, etc.).

This series makes tools/include/linux/compiler-context-analysis.h
functional by synchronizing it and the required compiler_types.h helpers
with the kernel headers, converts tools/perf from its custom mutex.h
macros to the kernel-style compiler-context-analysis.h annotations, and
expands context analysis coverage across comm, dso/dsos, thread/threads,
config, intel-tpebs, env, and maps. Along the way, separate preparatory
patches fix an unlocked __dsos__add() call and TOCTOU race in
__machine__addnew_vdso(), avoid dropping _dso__data_open_lock in
dso__list_del() under REFCNT_CHECKING, switch dso__data_open_lock and
tpebs_mtx to DEFINE_MUTEX(), add a read-lock fast path to
dsos__findnew_id(), fix an unlocked read of tpebs_reader_thread and
double-close of tpebs_cmd.out in intel-tpebs, and avoid a potential
read-to-write deadlock in maps__load_first() and out-of-bounds access in
__maps__remove().

This series was developed and reviewed with assistance from an AI coding
agent (Gemini 3.1 Pro) and reviewed with Sashiko.

v4:
  - Place the DSO loaded in addr_filter__resolve_syms() into a dsos
    collection so dso__dsos(dso) is populated (patch 8).
  - Join tpebs_reader_thread on error in evsel__tpebs_open(), document
    why tpebs_cmd.pid is cleared before pthread_join() in tpebs_stop(),
    and include <pthread.h> and <signal.h> in util/intel-tpebs.c
    (patch 13).
  - Include <string.h> in util/maps.c (patch 16).

v3:
  - Rebase onto perf-tools-next (converting the newly added
    dso__find_binary_type() lock annotations in util/dso.c).
  - Separate bug fixes, DEFINE_MUTEX() cleanups, and improvements (vdso,
    dso_data, dso__data_open_lock, dsos__findnew_id, intel-tpebs,
    tpebs_mtx, maps) from the annotation patches.
  - Move AI coding assistant attribution to the cover letter and drop
    per-commit Assisted-by tags per linux-next
    Documentation/process/coding-assistants.rst.
  - Add Marco Elver's Reviewed-by to patch 1.
  - Define __diag_clang_23() and Clang ASM_INPUT_G/ASM_INPUT_RM/
    ASM_OUTPUT_RM overrides in tools/include/linux/compiler-gcc.h
    (patch 2).
  - Probe for -Wthread-safety-pointer/-Wthread-safety-beta in
    Makefile.config (patch 5).
  - Pass write_locked to __dsos__find() (patch 7).
  - Pass struct dso_data * to close_data_fd() and dso__list_del() to
    remove the REFCNT_CHECKING dso pointer from struct dso_data and
    avoid dropping dso__data_open_lock in dso__list_del(), and include
    <assert.h> in util/dso.c (patch 8).
  - Re-validate DSO lookup under the write lock in dsos__findnew_id()
    via __dsos__findnew_id(), and handle NULL dso_id in
    dso__needs_improve_id(), __dso__improve_id(), and dso_id__cmp()
    (patch 10).
  - Reset tpebs_cmd.out = -1 if start_command() fails and include
    <stdint.h>, <stdlib.h>, <string.h>, and <unistd.h> in
    util/intel-tpebs.c (patch 13).
  - Bounds-check the index in __maps__remove() (freeing maps_by_name if
    out of bounds) (patch 16).

v2:
  - Use -c rather than -E when probing for
    -fexperimental-late-parse-attributes in Makefile.config to avoid
    -Werror,-Wunused-command-line-argument.
  - Acquire machine->dsos.lock in write mode across duplicate checking,
    dso__set_long_name(), and __dsos__add() in __machine__addnew_vdso().
  - Avoid dropping dso__data_open_lock in dso__list_del() under
    REFCNT_CHECKING.
  - Pass tpebs_cmd.out directly to __sample_reader() and set
    tpebs_cmd.out = -1 in evsel__tpebs_open() to avoid a double-close in
    tpebs_stop(), and clarify the config_set_mutex comment.
  - Drop maps__lock before calling map__load() in maps__load_first() to
    avoid a read-to-write self-deadlock when loading kernel maps inserts
    additional trampoline maps.

Ian Rogers (17):
  compiler-context-analysis: Avoid unused parameter warning in
    _context_unsafe_alias()
  tools headers compiler: Synchronize compiler_types.h with the kernel
    sources
  tools headers: Synchronize linux/compiler-context-analysis.h with the
    kernel sources
  perf mutex: Use kernel style compiler-context-analysis.h annotations
  perf build: Enable additional Clang thread-safety flags
  perf comm: Add __guarded_by annotations to struct comm_strs
  perf vdso: Fix unlocked __dsos__add() and race in
    __machine__addnew_vdso()
  perf dso: Pass dso_data to close_data_fd() and dso__list_del()
  perf dso: Use DEFINE_MUTEX for dso__data_open_lock
  perf dsos: Use read lock fast path in dsos__findnew_id()
  perf dso: Expand context analysis annotations
  perf thread: Expand context analysis annotations to threads and
    namespaces_lock
  perf intel-tpebs: Fix race in tpebs_stop() and tpebs_cmd.out fd
    handling
  perf intel-tpebs: Use DEFINE_MUTEX for tpebs_mtx
  perf config, intel-tpebs, env: Add __guarded_by and __must_hold
    annotations
  perf maps: Fix lock inversion in maps__load_first() and bounds check
    in __maps__remove()
  perf maps: Add context analysis annotations

 include/linux/compiler-context-analysis.h     |   2 +-
 .../include/linux/compiler-context-analysis.h | 518 ++++++++++++++++--
 tools/include/linux/compiler-gcc.h            |  72 ++-
 tools/include/linux/compiler.h                |  50 +-
 tools/include/linux/compiler_types.h          | 206 ++++++-
 tools/perf/Makefile.config                    |   8 +-
 tools/perf/builtin-sched.c                    |  16 +-
 tools/perf/builtin-top.c                      |   4 +-
 tools/perf/check-headers.sh                   |   1 +
 tools/perf/tests/dso-data.c                   |   4 +
 tools/perf/util/annotate.c                    |   4 +-
 tools/perf/util/annotate.h                    |   8 +-
 tools/perf/util/auxtrace.c                    |  16 +-
 tools/perf/util/bpf-event.h                   |   5 +-
 tools/perf/util/comm.c                        |  10 +-
 tools/perf/util/config.c                      |  43 +-
 tools/perf/util/dso.c                         | 140 +++--
 tools/perf/util/dso.h                         |  15 +-
 tools/perf/util/dsos.c                        |  31 +-
 tools/perf/util/dsos.h                        |  12 +-
 tools/perf/util/env.c                         |   1 +
 tools/perf/util/env.h                         |  19 +-
 tools/perf/util/intel-tpebs.c                 | 128 +++--
 tools/perf/util/libbfd.c                      |   4 +-
 tools/perf/util/maps.c                        | 148 +++--
 tools/perf/util/mutex.c                       |   4 +-
 tools/perf/util/mutex.h                       |  90 +--
 tools/perf/util/rwsem.c                       |   8 +-
 tools/perf/util/rwsem.h                       |  10 +-
 tools/perf/util/thread.c                      |  10 +-
 tools/perf/util/thread.h                      |  30 +-
 tools/perf/util/threads.c                     |   4 +
 tools/perf/util/threads.h                     |   6 +-
 tools/perf/util/vdso.c                        |  17 +-
 34 files changed, 1181 insertions(+), 463 deletions(-)

-- 
2.56.0.212.g129ede20d9-goog