This adds functions for both executing the tests as well as parsing TAP
kmsg output.

Changes since v1:
- Correct handling of read to deal with partial buffer.

Signed-off-by: Isabella Basso <isabbasso@riseup.net>
---
 lib/igt_kmod.c | 169 +++++++++++++++++++++++++++++++++++++++++++++++++
 lib/igt_kmod.h |  13 ++++
 2 files changed, 182 insertions(+)

diff --git a/lib/igt_kmod.c b/lib/igt_kmod.c
index cf7a3b22..5d8e8b94 100644
--- a/lib/igt_kmod.c
+++ b/lib/igt_kmod.c
@@ -345,6 +345,175 @@ igt_kmod_list_loaded(void)
 	kmod_module_unref_list(list);
 }
 
+static void kmsg_parse_tap(int fd)
+{
+	char record[4096 + 1];
+	const char *num_tests_str, *nok_str, *ok_str, *end_str_success, *end_str_fail;
+	bool has_num = false;
+
+	num_tests_str = "..";
+	nok_str = "    not ok ";
+	ok_str = "    ok ";
+	end_str_fail = "not ok ";
+	end_str_success = "ok ";
+
+	if (fd == -1) {
+		igt_warn("Unable to retrieve kernel log (from /dev/kmsg)\n");
+		return;
+	}
+
+	record[sizeof(record) - 1] = '\0';
+
+	for (;;) {
+		const char *end, *result;
+		ssize_t r;
+
+		r = read(fd, record, sizeof(record) - 1);
+		if (r < 0) {
+			if (errno == EINTR)
+				continue;
+
+			if (errno == EPIPE) {
+				igt_warn("kmsg truncated: too many messages. You may want to increase log_buf_len in kmcdline\n");
+				continue;
+			}
+
+			if (errno != EAGAIN)
+				igt_warn("kmsg truncated: unknown error (%m)\n");
+
+			break;
+		}
+
+		/* deal with partial string from read */
+		if (record[r - 1] == NULL) {
+			fseek(fd, 0, end);
+			continue;
+		}
+
+		if (!has_num) {
+			result = strstr(record, num_tests_str);
+			if (result) {
+				result += strlen(num_tests_str);
+				end = strchrnul(result, '\n');
+				igt_info("[IGT] running %.*s tests...\n",
+					 (int)(end - result), result);
+				has_num = true;
+			}
+			continue;
+		}
+
+		/* all results have 'ok' in them */
+		result = strstr(record, "ok");
+
+		if (result) {
+			end = strchrnul(result, '\n');
+
+			/* subtest succeded (i.e. ok_str) */
+			result = strstr(record, ok_str);
+
+			if (result) {
+				result += strlen(ok_str);
+				igt_info("[IGT] SUBTEST %.*s\n",
+					 (int)(end - result), result);
+				continue;
+			}
+
+			/* subtest failed (i.e. nok_str) */
+			result = strstr(record, nok_str);
+
+			if (result) {
+				result += strlen(nok_str);
+				igt_warn("[IGT] SUBTEST FAILED %.*s\n",
+					 (int)(end - result), result);
+				continue;
+			}
+
+			/* test ended (i.e. end_str_success) */
+			result = strchr(record, ';') + 1;
+
+			if (strncmp(result, end_str_success, strlen(end_str_success)) == 0) {
+				igt_info("[IGT] TEST SUCCEEDED %.*s\n",
+					 (int)(end - result), result);
+
+				igt_success();
+			}
+
+			if (strncmp(result, end_str_fail, strlen(end_str_fail)) == 0) {
+				igt_warn("[IGT] TEST FAILED %.*s\n",
+					 (int)(end - result), result);
+				igt_fail(IGT_EXIT_FAILURE);
+			}
+		}
+	}
+}
+
+/**
+ * igt_kunit: tests a kunit module
+ * @mod_name: the name of the module
+ * @options: options to load the module
+ * @req_mods: array with additional dependencies to run the KUnit test
+ * @req_mod_len: size of req_mods array
+ *
+ * Loads the kunit module, parses its dmesg output, then unloads it
+ */
+void igt_kunit(const char *mod_name, const char *options,
+	       const char **req_mods, int req_mod_len)
+{
+	int kmsg_fd, cmi;
+	struct igt_kselftest tst;
+	const char *norm_name;
+
+	/* get normalized module name */
+	igt_require(igt_kselftest_init(&tst, mod_name) == 0);
+
+	norm_name = kmod_module_get_name(tst.kmod);
+
+	if (!igt_kmod_is_loaded(norm_name)) {
+		/* The kunit module is required for running any kunit tests */
+		if (!igt_kmod_is_loaded("kunit"))
+			igt_require(igt_kmod_load("kunit", NULL) == 0);
+
+		for (cmi = 0; cmi < req_mod_len; cmi++) {
+			if (strcmp(req_mods[cmi], "kunit") == 0)
+				continue;
+			if (igt_kmod_load(req_mods[cmi], NULL))
+				goto unload;
+		}
+	} else {
+		/* Unload module if loaded (maybe previous run bailed out?) */
+		igt_kmod_unload(mod_name, 0);
+	}
+
+	kmsg_fd = open("/dev/kmsg", O_RDONLY | O_NONBLOCK);
+
+	if (kmsg_fd < 0) {
+		igt_warn("Could not open /dev/kmsg");
+		goto unload;
+	}
+
+	if (lseek(kmsg_fd, 0, SEEK_END)) {
+		igt_warn("Could not seek the end of /dev/kmsg");
+		close(kmsg_fd);
+		goto unload;
+	}
+
+	igt_require(igt_kmod_load(mod_name, options) == 0);
+
+	kmsg_parse_tap(kmsg_fd);
+
+	igt_kmod_unload(mod_name, 0);
+
+	close(kmsg_fd);
+unload:
+	igt_kmod_unload("kunit", 0);
+
+	for (cmi--; cmi >= 0; cmi--) {
+		if (strcmp(req_mods[cmi], "kunit") == 0)
+			continue;
+		igt_kmod_unload(req_mods[cmi], 0);
+	}
+}
+
 /**
  * igt_i915_driver_load:
  * @opts: options to pass to i915 driver
diff --git a/lib/igt_kmod.h b/lib/igt_kmod.h
index 0898122b..60e7a750 100644
--- a/lib/igt_kmod.h
+++ b/lib/igt_kmod.h
@@ -28,6 +28,16 @@
 
 #include "igt_list.h"
 
+#define MAX_MOD_NAME_LEN 40
+
+/**
+ * ARRAY_SIZE:
+ * @arr: static array
+ *
+ * Macro to compute the size of the static array @arr.
+ */
+#define ARRAY_SIZE(arr) (sizeof(arr)/sizeof(arr[0]))
+
 bool igt_kmod_is_loaded(const char *mod_name);
 void igt_kmod_list_loaded(void);
 
@@ -36,6 +46,9 @@ bool igt_kmod_has_param(const char *mod_name, const char *param);
 int igt_kmod_load(const char *mod_name, const char *opts);
 int igt_kmod_unload(const char *mod_name, unsigned int flags);
 
+void igt_kunit(const char *mod_name, const char *options,
+	       const char **req_mods, int req_mod_len);
+
 int igt_i915_driver_load(const char *opts);
 int igt_i915_driver_unload(void);
 int __igt_i915_driver_unload(const char **whom);
-- 
2.35.1

This adds a converted KUnit test module to IGT.

Signed-off-by: Isabella Basso <isabbasso@riseup.net>
---
 lib/igt_kmod.c    | 41 ++++++++++++++++++++++++++++++-----------
 tests/kms_kunit.c | 34 ++++++++++++++++++++++++++++++++++
 tests/meson.build |  1 +
 3 files changed, 65 insertions(+), 11 deletions(-)
 create mode 100644 tests/kms_kunit.c

diff --git a/lib/igt_kmod.c b/lib/igt_kmod.c
index 5d8e8b94..14f1939d 100644
--- a/lib/igt_kmod.c
+++ b/lib/igt_kmod.c
@@ -364,12 +364,24 @@ static void kmsg_parse_tap(int fd)
 
 	record[sizeof(record) - 1] = '\0';
 
-	for (;;) {
+	while (true) {
 		const char *end, *result;
 		ssize_t r;
+		bool skip = true;
 
-		r = read(fd, record, sizeof(record) - 1);
-		if (r < 0) {
+		if (!skip) {
+			end = strchrnul(record, '\n');
+		} else {
+			end = NULL;
+			skip = false;
+		}
+
+		r = read(fd, record,
+			 end != NULL ?
+				(int) (end - record) :
+				sizeof(record) - 1);
+
+		if (r <= 0) {
 			if (errno == EINTR)
 				continue;
 
@@ -384,19 +396,19 @@ static void kmsg_parse_tap(int fd)
 			break;
 		}
 
-		/* deal with partial string from read */
-		if (record[r - 1] == NULL) {
-			fseek(fd, 0, end);
-			continue;
-		}
-
 		if (!has_num) {
 			result = strstr(record, num_tests_str);
 			if (result) {
 				result += strlen(num_tests_str);
 				end = strchrnul(result, '\n');
-				igt_info("[IGT] running %.*s tests...\n",
-					 (int)(end - result), result);
+				/* in case line > 4096 */
+				if (end == NULL) {
+					igt_info("%s\n", record);
+				}
+				else {
+					igt_info("[IGT] running %.*s tests...\n",
+						 (int)(end - result), result);
+				}
 				has_num = true;
 			}
 			continue;
@@ -407,6 +419,11 @@ static void kmsg_parse_tap(int fd)
 
 		if (result) {
 			end = strchrnul(result, '\n');
+			/* in case line > 4096 */
+			if (end == NULL) {
+				igt_info("%s\n", record);
+				continue;
+			}
 
 			/* subtest succeded (i.e. ok_str) */
 			result = strstr(record, ok_str);
@@ -429,6 +446,7 @@ static void kmsg_parse_tap(int fd)
 			}
 
 			/* test ended (i.e. end_str_success) */
+			/* we should skip the ; in the beginning of the string */
 			result = strchr(record, ';') + 1;
 
 			if (strncmp(result, end_str_success, strlen(end_str_success)) == 0) {
@@ -444,6 +462,7 @@ static void kmsg_parse_tap(int fd)
 				igt_fail(IGT_EXIT_FAILURE);
 			}
 		}
+		skip = true;
 	}
 }
 
diff --git a/tests/kms_kunit.c b/tests/kms_kunit.c
new file mode 100644
index 00000000..31566910
--- /dev/null
+++ b/tests/kms_kunit.c
@@ -0,0 +1,34 @@
+/*
+ * Copyright © 2021 Isabella Basso do Amaral <isabbasso@riseup.net>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include <libkmod.h>
+
+#include "igt.h"
+#include "igt_kmod.h"
+
+IGT_TEST_DESCRIPTION("KUnit DRM damage helper module testing");
+
+igt_simple_main
+{
+	igt_kunit("test-drm_damage_helper", NULL, NULL, 0);
+}
diff --git a/tests/meson.build b/tests/meson.build
index 3dbba7a1..6d3685c3 100644
--- a/tests/meson.build
+++ b/tests/meson.build
@@ -36,6 +36,7 @@ test_progs = [
 	'kms_hdmi_inject',
 	'kms_hdr',
 	'kms_invalid_mode',
+	'kms_kunit',
 	'kms_lease',
 	'kms_multipipe_modeset',
 	'kms_panel_fitting',
-- 
2.35.1