[PATCH 0/6] samples/damon: handle damon_{start,stop}() failures

[SJ Park <sj@kernel.org>]

All DAMON sample modules are not correctly handling failures from
damon_start().  Among those, mtier also has an additional problem for
handling of damon_stop() failures.  wsse and prcl also have a problem in
their damon_call() failure handling.  As a result, memory leaks, next
DAMON operation disruptions, and use-after-free can happen.  Fix those.

Note that only the damon_start() failure caused issues can reliably be
reproduced.  Reproducing those issues require the admin permission,
though.

Changes from RFC v4
- RFC v4: https://lore.kernel.org/20260610135546.64943-1-sj@kernel.org/
- Collect R-b: from Zenghui Yu.
- Rebase to latest mm-new.
- Drop RFC.
Changes from RFC v3
- RFC v3: https://lore.kernel.org/20260610011420.3018-1-sj@kernel.org
- Add damon_Call() failure handling fixes for wsse and prcl.
Changes from RFC v2
- RFC v2: https://lore.kernel.org/20260609142119.68120-1-sj@kernel.org
- Add damon_start() failure handling fixes for wsse and prcl.
Changes from RFC v1
- RFC v1: https://lore.kernel.org/20260609005443.2122-1-sj@kernel.org
- Add damon_stop() failure handling fix to the series.

SJ Park (6):
  samples/damon/wsse: handle damon_start() failure
  samples/damon/prcl: handle damon_start() failure
  samples/damon/mtier: handle damon_start() failure
  samples/damon/mtier: handle damon_stop() failure
  samples/damon/wsse: stop and free damon ctx when damon_call() fails
  samples/damon/prcl: stop and free damon ctx when damon_call() fails

 samples/damon/mtier.c | 14 ++++++++++++--
 samples/damon/prcl.c  | 11 +++++++++--
 samples/damon/wsse.c  | 11 +++++++++--
 3 files changed, 30 insertions(+), 6 deletions(-)


base-commit: 77fe35dfe005f7d55c8e729e1543b87cfc805a21
-- 
2.47.3