In preparation to enable -Wimplicit-fallthrough for Clang, fix multiple
warnings by explicitly adding multiple break statements instead of
letting the code fall through to the next case, and by replacing a
number of /* fall through */ comments with the new pseudo-keyword
macro fallthrough.
Notice that Clang doesn't recognize /* Fall through */ comments as
implicit fall-through markings.
Link: https://github.com/KSPP/linux/issues/115
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
commit 5c47251e8c4903111608ddcba2a77c0c425c247c upstream.
A refcount issue can appeared in __fwnode_link_del() due to the
pr_debug() call:
WARNING: CPU: 0 PID: 901 at lib/refcount.c:25 refcount_warn_saturate+0xe5/0x110
Call Trace:
<TASK>
...
of_node_get+0x1e/0x30
of_fwnode_get+0x28/0x40
fwnode_full_name_string+0x34/0x90
fwnode_string+0xdb/0x140
...
vsnprintf+0x17b/0x630
...
__fwnode_link_del+0x25/0xa0
fwnode_links_purge+0x39/0xb0
of_node_release+0xd9/0x180
...
Indeed, an fwnode (of_node) is being destroyed and so, of_node_release()
is called because the of_node refcount reached 0.
From of_node_release() several function calls are done and lead to
a pr_debug() calls with %pfwf to print the fwnode full name.
The issue is not present if we change %pfwf to %pfwP.
To print the full name, %pfwf iterates over the current node and its
parents and obtain/drop a reference to all nodes involved.
In order to allow to print the full name (%pfwf) of a node while it is
being destroyed, do not obtain/drop a reference to this current node.
Fixes: a92eb7621b9f ("lib/vsprintf: Make use of fwnode API to obtain node names and separators")
Cc: stable@vger.kernel.org
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20231114152655.409331-1-herve.codina@bootlin.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
