[PATCH v4 i-g-t 2/3] lib/igt_kmod: Add IGT_HOOK_POST_KMOD_UNBIND

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

Adds an igt_hook after the unbind operation of the kmod intended as
a strategice entry point for kmemleak scans.

Can be used with --hook  'post-kmod-unbind:...'

Cc: Gustavo Sousa <gustavo.sousa@intel.com>
Cc: Kamil Konieczny <kamil.konieczny@linux.intel.com>
Signed-off-by: Peter Senna Tschudin <peter.senna@linux.intel.com>
---
v4:
 - unchanged from v3

v3:
  - Renamed the hook to IGT_HOOK_POST_KMOD_UNBIND as the unbind can also happen
   for snd modules
 - Changed the logic for the IGT_HOOK_KMOD_UNBIND_MODULE_NAME env var so that
   it is only populated when the correct hook is used.

v2:
 - Added code ducumentation for new hook
 - Added env var IGT_HOOK_KMOD_UNBIND_MODULE_NAME and extended help text

 lib/igt_hook.c | 11 +++++++++++
 lib/igt_hook.h |  3 +++
 lib/igt_kmod.c |  8 ++++++++
 3 files changed, 22 insertions(+)

diff --git a/lib/igt_hook.c b/lib/igt_hook.c
index 8932d118d..f86ed56f7 100644
--- a/lib/igt_hook.c
+++ b/lib/igt_hook.c
@@ -74,6 +74,8 @@ static const char *igt_hook_evt_type_to_name(enum igt_hook_evt_type evt_type)
 		return "post-subtest";
 	case IGT_HOOK_POST_TEST:
 		return "post-test";
+	case IGT_HOOK_POST_KMOD_UNBIND:
+		return "post-kmod-unbind";
 	case IGT_HOOK_NUM_EVENTS:
 		break;
 	/* No "default:" case, to force a warning from -Wswitch in case we miss
@@ -335,6 +337,8 @@ static void igt_hook_update_env_vars(struct igt_hook *igt_hook, struct igt_hook_
 	setenv("IGT_HOOK_TEST", igt_hook->test_name, 1);
 	setenv("IGT_HOOK_SUBTEST", igt_hook->subtest_name, 1);
 	setenv("IGT_HOOK_DYN_SUBTEST", igt_hook->dyn_subtest_name, 1);
+	setenv("IGT_HOOK_KMOD_UNBIND_MODULE_NAME",
+	       evt->evt_type == IGT_HOOK_POST_KMOD_UNBIND ? evt->target_name : "", 1);
 	setenv("IGT_HOOK_RESULT", evt->result ?: "", 1);
 }
 
@@ -470,6 +474,9 @@ below:\n\
 		case IGT_HOOK_POST_TEST:
 			desc = "Occurs after a test case has finished.";
 			break;
+		case IGT_HOOK_POST_KMOD_UNBIND:
+			desc = "Occurs after the kernel module is unbound from the device.";
+			break;
 		default:
 			desc = "MISSING DESCRIPTION";
 		}
@@ -504,6 +511,10 @@ available to the command:\n\
   values are: SUCCESS, SKIP or FAIL. This is only applicable on \"post-*\"\n\
   events and will be the empty string for other types of events.\n\
 \n\
+  IGT_HOOK_KMOD_UNBIND_MODULE_NAME\n\
+  Name of the kernel module that was unbound from the device. This is only\n\
+  applicable on the `IGT_HOOK_POST_KMOD_UNBIND` event and will be the empty\n\
+  string for other types of events.\n\
 \n\
 Note that %s can be passed multiple times. Each descriptor is evaluated in turn\n\
 when matching events and running hook commands.\n\
diff --git a/lib/igt_hook.h b/lib/igt_hook.h
index e9f97b79b..11d839dfd 100644
--- a/lib/igt_hook.h
+++ b/lib/igt_hook.h
@@ -26,6 +26,8 @@ struct igt_hook;
  * @IGT_HOOK_POST_SUBTEST: Occurs after the execution of a subtest..
  * @IGT_HOOK_POST_TEST: Occurs after a test case (executable) is finished with
  * the test code.
+ * @IGT_HOOK_POST_KMOD_UNBIND: Occurs after the kernel module is unbound
+ * from the device.
  * @IGT_HOOK_NUM_EVENTS: This is not really an event and represents the number
  * of possible events tracked by igt_hook.
  *
@@ -39,6 +41,7 @@ enum igt_hook_evt_type {
 	IGT_HOOK_POST_DYN_SUBTEST,
 	IGT_HOOK_POST_SUBTEST,
 	IGT_HOOK_POST_TEST,
+	IGT_HOOK_POST_KMOD_UNBIND,
 	IGT_HOOK_NUM_EVENTS /* This must always be the last one. */
 };
 
diff --git a/lib/igt_kmod.c b/lib/igt_kmod.c
index 6d7f5705c..a10626eed 100644
--- a/lib/igt_kmod.c
+++ b/lib/igt_kmod.c
@@ -41,6 +41,7 @@
 #include "igt_aux.h"
 #include "igt_core.h"
 #include "igt_debugfs.h"
+#include "igt_hook.h"
 #include "igt_kmod.h"
 #include "igt_ktap.h"
 #include "igt_sysfs.h"
@@ -604,6 +605,7 @@ int __igt_intel_driver_unload(char **who, const char *driver)
  */
 int igt_kmod_unbind(const char *mod_name, const char *pci_device)
 {
+	struct igt_hook *igt_hook = NULL;
 	char path[PATH_MAX];
 	struct dirent *de;
 	int dirlen;
@@ -634,6 +636,12 @@ int igt_kmod_unbind(const char *mod_name, const char *pci_device)
 
 	closedir(dir);
 
+	igt_hook = igt_core_get_igt_hook();
+	igt_hook_event_notify(igt_hook, &(struct igt_hook_evt){
+		.evt_type = IGT_HOOK_POST_KMOD_UNBIND,
+		.target_name = mod_name,
+	});
+
 	return 0;
 }
 
-- 
2.43.0