Merge tag 'linux_kselftest-kunit-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull KUnit updates from Shuah Khan:

 - a new feature that adds APIs for managing devices introducing a set
   of helper functions which allow devices (internally a struct
   kunit_device) to be created and managed by KUnit.

   These devices will be automatically unregistered on test exit. These
   helpers can either use a user-provided struct device_driver, or have
   one automatically created and managed by KUnit. In both cases, the
   device lives on a new kunit_bus.

 - changes to switch drm/tests to use kunit devices

 - several fixes and enhancements to attribute feature

 - changes to reorganize deferred action function introducing
   KUNIT_DEFINE_ACTION_WRAPPER

 - new feature adds ability to run tests after boot using debugfs

 - fixes and enhancements to string-stream-test:
     - parse ERR_PTR in string_stream_destroy()
     - unchecked dereference in bug fix in debugfs_print_results()
     - handling errors from alloc_string_stream()
     - NULL-dereference bug fix in kunit_init_suite()

* tag 'linux_kselftest-kunit-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (27 commits)
  kunit: Fix some comments which were mistakenly kerneldoc
  kunit: Protect string comparisons against NULL
  kunit: Add example of kunit_activate_static_stub() with pointer-to-function
  kunit: Allow passing function pointer to kunit_activate_static_stub()
  kunit: Fix NULL-dereference in kunit_init_suite() if suite->log is NULL
  kunit: Reset test->priv after each param iteration
  kunit: Add example for using test->priv
  drm/tests: Switch to kunit devices
  ASoC: topology: Replace fake root_device with kunit_device in tests
  overflow: Replace fake root_device with kunit_device
  fortify: test: Use kunit_device
  kunit: Add APIs for managing devices
  Documentation: Add debugfs docs with run after boot
  kunit: add ability to run tests after boot using debugfs
  kunit: add is_init test attribute
  kunit: add example suite to test init suites
  kunit: add KUNIT_INIT_TABLE to init linker section
  kunit: move KUNIT_TABLE out of INIT_DATA
  kunit: tool: add test for parsing attributes
  kunit: tool: fix parsing of test attributes
  ...

1 files changed, 96 insertions, 6 deletions

diff --git a/lib/kunit/debugfs.c b/lib/kunit/debugfs.c
index 270d185737e6..d548750a325a 100644
--- a/lib/kunit/debugfs.c
+++ b/lib/kunit/debugfs.c
@@ -8,12 +8,14 @@
 #include <linux/module.h>
 
 #include <kunit/test.h>
+#include <kunit/test-bug.h>
 
 #include "string-stream.h"
 #include "debugfs.h"
 
 #define KUNIT_DEBUGFS_ROOT             "kunit"
 #define KUNIT_DEBUGFS_RESULTS          "results"
+#define KUNIT_DEBUGFS_RUN              "run"
 
 /*
  * Create a debugfs representation of test suites:
@@ -21,6 +23,8 @@
  * Path						Semantics
  * /sys/kernel/debug/kunit/<testsuite>/results	Show results of last run for
  *						testsuite
+ * /sys/kernel/debug/kunit/<testsuite>/run	Write to this file to trigger
+ *						testsuite to run
  *
  */
 
@@ -60,12 +64,14 @@ static void debugfs_print_result(struct seq_file *seq, struct string_stream *log
 static int debugfs_print_results(struct seq_file *seq, void *v)
 {
 	struct kunit_suite *suite = (struct kunit_suite *)seq->private;
-	enum kunit_status success = kunit_suite_has_succeeded(suite);
+	enum kunit_status success;
 	struct kunit_case *test_case;
 
 	if (!suite)
 		return 0;
 
+	success = kunit_suite_has_succeeded(suite);
+
 	/* Print KTAP header so the debugfs log can be parsed as valid KTAP. */
 	seq_puts(seq, "KTAP version 1\n");
 	seq_puts(seq, "1..1\n");
@@ -99,6 +105,51 @@ static int debugfs_results_open(struct inode *inode, struct file *file)
 	return single_open(file, debugfs_print_results, suite);
 }
 
+/*
+ * Print a usage message to the debugfs "run" file
+ * (/sys/kernel/debug/kunit/<testsuite>/run) if opened.
+ */
+static int debugfs_print_run(struct seq_file *seq, void *v)
+{
+	struct kunit_suite *suite = (struct kunit_suite *)seq->private;
+
+	seq_puts(seq, "Write to this file to trigger the test suite to run.\n");
+	seq_printf(seq, "usage: echo \"any string\" > /sys/kernel/debugfs/kunit/%s/run\n",
+			suite->name);
+	return 0;
+}
+
+/*
+ * The debugfs "run" file (/sys/kernel/debug/kunit/<testsuite>/run)
+ * contains no information. Write to the file to trigger the test suite
+ * to run.
+ */
+static int debugfs_run_open(struct inode *inode, struct file *file)
+{
+	struct kunit_suite *suite;
+
+	suite = (struct kunit_suite *)inode->i_private;
+
+	return single_open(file, debugfs_print_run, suite);
+}
+
+/*
+ * Trigger a test suite to run by writing to the suite's "run" debugfs
+ * file found at: /sys/kernel/debug/kunit/<testsuite>/run
+ *
+ * Note: what is written to this file will not be saved.
+ */
+static ssize_t debugfs_run(struct file *file,
+		const char __user *buf, size_t count, loff_t *ppos)
+{
+	struct inode *f_inode = file->f_inode;
+	struct kunit_suite *suite = (struct kunit_suite *) f_inode->i_private;
+
+	__kunit_test_suites_init(&suite, 1);
+
+	return count;
+}
+
 static const struct file_operations debugfs_results_fops = {
 	.open = debugfs_results_open,
 	.read = seq_read,
@@ -106,17 +157,43 @@ static const struct file_operations debugfs_results_fops = {
 	.release = debugfs_release,
 };
 
+static const struct file_operations debugfs_run_fops = {
+	.open = debugfs_run_open,
+	.read = seq_read,
+	.write = debugfs_run,
+	.llseek = seq_lseek,
+	.release = debugfs_release,
+};
+
 void kunit_debugfs_create_suite(struct kunit_suite *suite)
 {
 	struct kunit_case *test_case;
+	struct string_stream *stream;
+
+	/* If suite log already allocated, do not create new debugfs files. */
+	if (suite->log)
+		return;
 
-	/* Allocate logs before creating debugfs representation. */
-	suite->log = alloc_string_stream(GFP_KERNEL);
-	string_stream_set_append_newlines(suite->log, true);
+	/*
+	 * Allocate logs before creating debugfs representation.
+	 * The suite->log and test_case->log pointer are expected to be NULL
+	 * if there isn't a log, so only set it if the log stream was created
+	 * successfully.
+	 */
+	stream = alloc_string_stream(GFP_KERNEL);
+	if (IS_ERR_OR_NULL(stream))
+		return;
+
+	string_stream_set_append_newlines(stream, true);
+	suite->log = stream;
 
 	kunit_suite_for_each_test_case(suite, test_case) {
-		test_case->log = alloc_string_stream(GFP_KERNEL);
-		string_stream_set_append_newlines(test_case->log, true);
+		stream = alloc_string_stream(GFP_KERNEL);
+		if (IS_ERR_OR_NULL(stream))
+			goto err;
+
+		string_stream_set_append_newlines(stream, true);
+		test_case->log = stream;
 	}
 
 	suite->debugfs = debugfs_create_dir(suite->name, debugfs_rootdir);
@@ -124,6 +201,19 @@ void kunit_debugfs_create_suite(struct kunit_suite *suite)
 	debugfs_create_file(KUNIT_DEBUGFS_RESULTS, S_IFREG | 0444,
 			    suite->debugfs,
 			    suite, &debugfs_results_fops);
+
+	/* Do not create file to re-run test if test runs on init */
+	if (!suite->is_init) {
+		debugfs_create_file(KUNIT_DEBUGFS_RUN, S_IFREG | 0644,
+				    suite->debugfs,
+				    suite, &debugfs_run_fops);
+	}
+	return;
+
+err:
+	string_stream_destroy(suite->log);
+	kunit_suite_for_each_test_case(suite, test_case)
+		string_stream_destroy(test_case->log);
 }
 
 void kunit_debugfs_destroy_suite(struct kunit_suite *suite)