[PATCH 1/2] ASoC: wm_adsp_fw_find_test: Redirect wm_adsp_release_firmware_files()

[Richard Fitzgerald <rf@opensource.cirrus.com>]

Redirect wm_adsp_release_firmware_files() to a replacement function that
handles the dummy firmware created by the tests. Use the same cleanup
function to cleanup in the test exit() function. Also call it on each
loop in wm_adsp_fw_find_test_find_firmware_byindex() to free the created
strings before reusing priv->found_fw on the next loop.

wm_adsp_release_firmware_files() will pass the struct firmware* pointers
to release_firmware(). But the pointers created by the tests are dummies
and must not be passed to release_firmware().

The test never invokes wm_adsp_release_firmware_files() so it wasn't
redirected. But the error handling in wm_adsp_request_firmware_files()
calls wm_adsp_release_firmware_files(). The redirected function makes
this safe.

Using the same cleanup function to perform cleanup from the test exit()
handler and wm_adsp_fw_find_test_find_firmware_byindex() avoids the risk
of duplicate cleanup code that all needs updating if there is any change
to the cleanup requirements.

This problem was found by https://sashiko.dev.

Fixes: bf2d44d07de7 ("ASoC: wm_adsp: Add kunit test for firmware file search")
Closes: https://sashiko.dev/#/patchset/20260326100853.1582886-1-rf%40opensource.cirrus.com
Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
---
 sound/soc/codecs/wm_adsp_fw_find_test.c | 56 ++++++++++++++++++++-----
 1 file changed, 46 insertions(+), 10 deletions(-)

diff --git a/sound/soc/codecs/wm_adsp_fw_find_test.c b/sound/soc/codecs/wm_adsp_fw_find_test.c
index d0c7fb30a95d..516ba08eb5ba 100644
--- a/sound/soc/codecs/wm_adsp_fw_find_test.c
+++ b/sound/soc/codecs/wm_adsp_fw_find_test.c
@@ -45,6 +45,34 @@ struct wm_adsp_fw_find_test_params {
 /* Dummy struct firmware to return from wm_adsp_request_firmware_files */
 static const struct firmware wm_adsp_find_test_dummy_firmware;
 
+static void wm_adsp_fw_find_test_release_firmware_files_stub(struct wm_adsp_fw_files *fw)
+{
+	/*
+	 * fw->wmfw.firmware and fw->coeff.firmware allocated by this KUnit
+	 * test are dummies not allocated by the real request_firmware() call
+	 * so they must not be passed to release_firmware().
+	 * This function replaces wm_adsp_release_firmware_files().
+	 */
+
+	if (!fw)
+		return;
+
+	kfree(fw->wmfw.filename);
+	kfree(fw->coeff.filename);
+
+	fw->wmfw.firmware = NULL;
+	fw->coeff.firmware = NULL;
+	fw->wmfw.filename = NULL;
+	fw->coeff.filename = NULL;
+}
+
+static void wm_adsp_free_found_fw(struct kunit *test)
+{
+	struct wm_adsp_fw_find_test *priv = test->priv;
+
+	wm_adsp_fw_find_test_release_firmware_files_stub(&priv->found_fw);
+}
+
 /* Simple lookup of a filename in a list of names */
 static int wm_adsp_fw_find_test_firmware_request_simple_stub(const struct firmware **firmware,
 							     const char *filename,
@@ -97,9 +125,14 @@ static void wm_adsp_fw_find_test_pick_file(struct kunit *test)
 	kunit_activate_static_stub(test,
 				   wm_adsp_firmware_request,
 				   wm_adsp_fw_find_test_firmware_request_simple_stub);
+	kunit_activate_static_stub(test,
+				   wm_adsp_release_firmware_files,
+				   wm_adsp_fw_find_test_release_firmware_files_stub);
 
 	ret = wm_adsp_request_firmware_files(dsp, &priv->found_fw);
 	kunit_deactivate_static_stub(test, wm_adsp_firmware_request);
+	kunit_deactivate_static_stub(test, wm_adsp_release_firmware_files);
+
 	KUNIT_EXPECT_EQ_MSG(test, ret,
 			    (params->expect_wmfw || params->expect_bin) ? 0 : -ENOENT,
 			    "%s\n", priv->searched_fw_files);
@@ -173,10 +206,13 @@ static void wm_adsp_fw_find_test_search_order(struct kunit *test)
 	kunit_activate_static_stub(test,
 				   wm_adsp_firmware_request,
 				   wm_adsp_fw_find_test_firmware_request_stub);
+	kunit_activate_static_stub(test,
+				   wm_adsp_release_firmware_files,
+				   wm_adsp_fw_find_test_release_firmware_files_stub);
 
 	wm_adsp_request_firmware_files(dsp, &priv->found_fw);
-
 	kunit_deactivate_static_stub(test, wm_adsp_firmware_request);
+	kunit_deactivate_static_stub(test, wm_adsp_release_firmware_files);
 
 	KUNIT_EXPECT_STREQ(test, priv->searched_fw_files, params->expected_searches);
 
@@ -201,6 +237,7 @@ static void wm_adsp_fw_find_test_find_firmware_byindex(struct kunit *test)
 
 	dsp->cs_dsp.name = "cs1234";
 	dsp->part = "dsp1";
+
 	for (dsp->fw = 0;; dsp->fw++) {
 		fw_name = wm_adsp_get_fwf_name_by_index(dsp->fw);
 		if (!fw_name)
@@ -209,14 +246,21 @@ static void wm_adsp_fw_find_test_find_firmware_byindex(struct kunit *test)
 		kunit_activate_static_stub(test,
 					   wm_adsp_firmware_request,
 					   wm_adsp_fw_find_test_firmware_request_stub);
+		kunit_activate_static_stub(test,
+					   wm_adsp_release_firmware_files,
+					   wm_adsp_fw_find_test_release_firmware_files_stub);
 
 		wm_adsp_request_firmware_files(dsp, &priv->found_fw);
+
 		kunit_deactivate_static_stub(test, wm_adsp_firmware_request);
+		kunit_deactivate_static_stub(test, wm_adsp_release_firmware_files);
 
 		KUNIT_EXPECT_NOT_NULL_MSG(test,
 					  strstr(priv->searched_fw_files, fw_name),
 					  "fw#%d Did not find '%s' in '%s'\n",
 					  dsp->fw, fw_name, priv->searched_fw_files);
+
+		wm_adsp_free_found_fw(test);
 	}
 }
 
@@ -255,15 +299,7 @@ static int wm_adsp_fw_find_test_case_init(struct kunit *test)
 
 static void wm_adsp_fw_find_test_case_exit(struct kunit *test)
 {
-	struct wm_adsp_fw_find_test *priv = test->priv;
-
-	/*
-	 * priv->found_wmfw_firmware and priv->found_bin_firmware are
-	 * dummies not allocated by the real request_firmware() call they
-	 * must not be passed to release_firmware().
-	 */
-	kfree(priv->found_fw.wmfw.filename);
-	kfree(priv->found_fw.coeff.filename);
+	wm_adsp_free_found_fw(test);
 }
 
 static void wm_adsp_fw_find_test_param_desc(const struct wm_adsp_fw_find_test_params *param,
-- 
2.47.3