On Tue, Jun 15 2021, Christoph Hellwig hch@lst.de wrote:

EPROBE_DEFER is an internal kernel error code and it should not be leaked to userspace via the bind_store() sysfs. Userspace doesn't have this constant and cannot understand it.

Further, it doesn't really make sense to have userspace trigger a deferred probe via bind_store(), which could eventually succeed, while simultaneously returning an error back.

Resolve this by splitting driver_probe_device so that the version used by the sysfs binding that turns EPROBE_DEFER into -EAGAIN, while the one used for internally binding keeps the error code, and calls driver_deferred_probe_add where needed. This also allows to nicely split out the defer_all_probes / probe_count checks so that they actually allow for full device_{block,unblock}_probing protection while not bothering the sysfs bind case.

Signed-off-by: Christoph Hellwig hch@lst.de Reviewed-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

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drivers/base/dd.c | 78 +++++++++++++++++++++++++---------------------- 1 file changed, 42 insertions(+), 36 deletions(-)

Reviewed-by: Cornelia Huck cohuck@redhat.com