Merge branch 'for-6.8/cxl-misc' into for-6.8/cxl

Pick up some miscellaneous fixups for v6.8.

3 files changed, 49 insertions, 4 deletions

diff --git a/lib/idr.c b/lib/idr.c
index 13f2758c2377..da36054c3ca0 100644
--- a/lib/idr.c
+++ b/lib/idr.c
@@ -508,7 +508,7 @@ void ida_free(struct ida *ida, unsigned int id)
 			goto delete;
 		xas_store(&xas, xa_mk_value(v));
 	} else {
-		if (!test_bit(bit, bitmap->bitmap))
+		if (!bitmap || !test_bit(bit, bitmap->bitmap))
 			goto err;
 		__clear_bit(bit, bitmap->bitmap);
 		xas_set_mark(&xas, XA_FREE_MARK);
diff --git a/lib/test_ida.c b/lib/test_ida.c
index b06880625961..55105baa19da 100644
--- a/lib/test_ida.c
+++ b/lib/test_ida.c
@@ -150,6 +150,45 @@ static void ida_check_conv(struct ida *ida)
 	IDA_BUG_ON(ida, !ida_is_empty(ida));
 }
 
+/*
+ * Check various situations where we attempt to free an ID we don't own.
+ */
+static void ida_check_bad_free(struct ida *ida)
+{
+	unsigned long i;
+
+	printk("vvv Ignore \"not allocated\" warnings\n");
+	/* IDA is empty; all of these will fail */
+	ida_free(ida, 0);
+	for (i = 0; i < 31; i++)
+		ida_free(ida, 1 << i);
+
+	/* IDA contains a single value entry */
+	IDA_BUG_ON(ida, ida_alloc_min(ida, 3, GFP_KERNEL) != 3);
+	ida_free(ida, 0);
+	for (i = 0; i < 31; i++)
+		ida_free(ida, 1 << i);
+
+	/* IDA contains a single bitmap */
+	IDA_BUG_ON(ida, ida_alloc_min(ida, 1023, GFP_KERNEL) != 1023);
+	ida_free(ida, 0);
+	for (i = 0; i < 31; i++)
+		ida_free(ida, 1 << i);
+
+	/* IDA contains a tree */
+	IDA_BUG_ON(ida, ida_alloc_min(ida, (1 << 20) - 1, GFP_KERNEL) != (1 << 20) - 1);
+	ida_free(ida, 0);
+	for (i = 0; i < 31; i++)
+		ida_free(ida, 1 << i);
+	printk("^^^ \"not allocated\" warnings over\n");
+
+	ida_free(ida, 3);
+	ida_free(ida, 1023);
+	ida_free(ida, (1 << 20) - 1);
+
+	IDA_BUG_ON(ida, !ida_is_empty(ida));
+}
+
 static DEFINE_IDA(ida);
 
 static int ida_checks(void)
@@ -162,6 +201,7 @@ static int ida_checks(void)
 	ida_check_leaf(&ida, 1024 * 64);
 	ida_check_max(&ida);
 	ida_check_conv(&ida);
+	ida_check_bad_free(&ida);
 
 	printk("IDA: %u of %u tests passed\n", tests_passed, tests_run);
 	return (tests_run != tests_passed) ? 0 : -EINVAL;
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 3e3733a7084f..552738f14275 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -2111,15 +2111,20 @@ char *fwnode_full_name_string(struct fwnode_handle *fwnode, char *buf,
 
 	/* Loop starting from the root node to the current node. */
 	for (depth = fwnode_count_parents(fwnode); depth >= 0; depth--) {
-		struct fwnode_handle *__fwnode =
-			fwnode_get_nth_parent(fwnode, depth);
+		/*
+		 * Only get a reference for other nodes (i.e. parent nodes).
+		 * fwnode refcount may be 0 here.
+		 */
+		struct fwnode_handle *__fwnode = depth ?
+			fwnode_get_nth_parent(fwnode, depth) : fwnode;
 
 		buf = string(buf, end, fwnode_get_name_prefix(__fwnode),
 			     default_str_spec);
 		buf = string(buf, end, fwnode_get_name(__fwnode),
 			     default_str_spec);
 
-		fwnode_handle_put(__fwnode);
+		if (depth)
+			fwnode_handle_put(__fwnode);
 	}
 
 	return buf;