[PATCH v2 i-g-t 0/2] Add post-gpukmod-unbind igt_hook

[Peter Senna Tschudin <peter.senna@linux.intel.com>]

Introduces a new IGT hook: IGT_HOOK_POST_GPUKMOD_UNBIND
(post-gpukmod-unbind), designed to facilitate kmemleak scans in our CI
workflows.

As suggested by Lucas de Marchi, a useful strategy for detecting memory
leaks is to run kmemleak scans both before binding and after unbinding
the GPU kernel module. This patch adds support for the latter scenario,
enabling automated scans immediately after the GPU module is unbound.

Example test-list:
 igt@xe_module_load@load
 igt@core_hotunplug@unbind-rebind
 igt@xe_module_load@unload

Usage Example:
 IGT_PING_HOSTNAME='10.211.176.1'
 IGT_TEST_ROOT='/home/gta/UPSTREAM/igt-gpu-tools/build/tests/'
 ./build/runner/igt_runner -o -l verbose -s --per-test-timeout 120 \
   --overall-timeout 960 --piglit-style-dmesg --dmesg-warn-level=4 \
   --use-watchdog --inactivity-timeout 90 \
   --abort-on-monitored-error=ping,taint --disk-usage-limit=10M \
   --facts --hook 'post-gpukmod-unbind:OUTF=/tmp/kmemleak-post-unbind && \
                   echo $IGT_HOOK_TEST_FULLNAME $IGT_HOOK_TEST $IGT_HOOK_SUBTEST >> $OUTF && \
                   echo scan > /sys/kernel/debug/kmemleak && \
                   cat /sys/kernel/debug/kmemleak >> $OUTF' \
   --test-list ~/igt/test-list \
   /home/gta/igt/0

Known Limitations: In certain cases, such as when running
igt@core_hotunplug@unbind-rebind, the unbind operation is explicitly
managed by igt_runner if the module is already loaded. However, if the
unbind occurs outside of igt_runner, the hook will not be triggered and
the scan will not run.

v2:
 - change function name to igt_core_get_igt_hook()
 - Add env var IGT_HOOK_KMOD_UNBIND_MODULE_NAME
 - Fix minor issues

Cc: Gustavo Sousa <gustavo.sousa@linux.intel.com>

Peter Senna Tschudin (2):
  igt_core_get_igt_hook: igt_hook pointer for other libs
  lib/igt_kmod: Add IGT_HOOK_POST_GPUKMOD_UNBIND

 lib/igt_core.c | 12 ++++++++++++
 lib/igt_core.h |  2 ++
 lib/igt_hook.c | 10 ++++++++++
 lib/igt_hook.h |  3 +++
 lib/igt_kmod.c |  8 ++++++++
 5 files changed, 35 insertions(+)

-- 
2.43.0