On Tue Mar 17, 2026 at 5:01 PM CET, Douglas Anderson wrote:

In various places in the kernel, we modify the fwnode "flags" member
by doing either:
  fwnode->flags |= SOME_FLAG;
  fwnode->flags &= ~SOME_FLAG;

This type of modification is not thread-safe. If two threads are both
mucking with the flags at the same time then one can clobber the
other.

While flags are often modified while under the "fwnode_link_lock",
this is not universally true.

Create some accessor functions for setting, clearing, and testing the
FWNODE flags and move all users to these accessor functions. New
accessor functions use set_bit() and clear_bit(), which are
thread-safe.

Cc: stable@vger.kernel.org
Fixes: c2c724c868c4 ("driver core: Add fw_devlink_parse_fwtree()")
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>

    [ Fix fwnode_clear_flag() argument alignment, restore dropped blank
      line in fwnode_dev_initialized(), and remove unnecessary parentheses
      around fwnode_test_flag() calls. - Danilo ]

Applied to driver-core-testing, thanks!