tests: lib: mpsc_pbuf: Fix address-of-packed-mem warning

The warning below appears once -Waddress-of-packed-mem is enabled:

/__w/zephyr/zephyr/tests/lib/mpsc_pbuf/src/main.c: In function
'item_put_data_overwrite':
/__w/zephyr/zephyr/tests/lib/mpsc_pbuf/src/main.c:497:3: error:
converting a packed 'struct test_data_ext' pointer (alignment 1) to a
'uint32_t' {aka 'const unsigned int'} pointer (alignment 4) may result
in an unaligned pointer value [-Werror=address-of-packed-member]
  497 |   mpsc_pbuf_put_data(&buffer, (uint32_t *)&item, len);

To avoid the warning, as well as several others related to the same
problem, use an intermediate void * variable.

More info in #16587.

Signed-off-by: Carles Cufi <[email protected]>

Author: carlescufi

tests/lib/mpsc_pbuf/src/main.c

@@ -492,9 +492,12 @@ void item_put_data_overwrite(bool pow2)
 	exp_dropped_len[1] = w;
 
 	for (uintptr_t i = 0; i < repeat; i++) {
+		void *vitem;
 		item.data = (void *)i;
 		item.hdr.data = i;
-		mpsc_pbuf_put_data(&buffer, (uint32_t *)&item, len);
+		vitem = (uint32_t *)&item;
+		zassert_true(IS_PTR_ALIGNED(vitem, uint32_t), "unaligned ptr");
+		mpsc_pbuf_put_data(&buffer, (uint32_t *)vitem, len);
 	}
 
 	uint32_t exp_drop_cnt = (sizeof(void *) == sizeof(uint32_t)) ?
@@ -978,6 +981,7 @@ void t_entry(void *p0, void *p1, void *p2)
 	struct mpsc_pbuf_buffer *buffer = p0;
 	uintptr_t wait_ms = (uintptr_t)p1;
 	struct test_data_ext *t;
+	void *vt;
 
 	t = (struct test_data_ext *)mpsc_pbuf_alloc(buffer,
 						    sizeof(*t) / sizeof(uint32_t),
@@ -990,7 +994,9 @@ void t_entry(void *p0, void *p1, void *p2)
 	t->hdr.len = PUT_EXT_LEN;
 	t->data = k_current_get();
 
-	mpsc_pbuf_commit(buffer, (union mpsc_pbuf_generic *)t);
+	vt = t;
+	zassert_true(IS_PTR_ALIGNED(vt, union mpsc_pbuf_generic), "unaligned ptr");
+	mpsc_pbuf_commit(buffer, (union mpsc_pbuf_generic *)vt);
 	while (1) {
 		k_sleep(K_MSEC(10));
 	}
@@ -1027,6 +1033,7 @@ void test_pending_alloc(void)
 {
 	int prio = k_thread_priority_get(k_current_get());
 	struct mpsc_pbuf_buffer buffer;
+	void *vt;
 
 	k_thread_priority_set(k_current_get(), 3);
 
@@ -1052,7 +1059,9 @@ void test_pending_alloc(void)
 
 		zassert_true(t, NULL);
 		zassert_equal(t->data, tids[ARRAY_SIZE(tids) - 1 - i], NULL);
-		mpsc_pbuf_free(&buffer, (union mpsc_pbuf_generic *)t);
+		vt = t;
+		zassert_true(IS_PTR_ALIGNED(vt, union mpsc_pbuf_generic), "unaligned ptr");
+		mpsc_pbuf_free(&buffer, (union mpsc_pbuf_generic *)vt);
 	}
 
 	zassert_equal(mpsc_pbuf_claim(&buffer), NULL, "No more packets.");