On Sun, Apr 11, 2021 at 12:23 AM gregkh@linuxfoundation.org wrote:
The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
I sent a patch that should resolve the conflict for 4.19 and 5.4. https://lore.kernel.org/lkml/20210412180907.1980874-1-saravanak@google.com/T...
-Saravana
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From eed6e41813deb9ee622cd9242341f21430d7789f Mon Sep 17 00:00:00 2001 From: Saravana Kannan saravanak@google.com Date: Thu, 1 Apr 2021 21:03:40 -0700 Subject: [PATCH] driver core: Fix locking bug in deferred_probe_timeout_work_func()
list_for_each_entry_safe() is only useful if we are deleting nodes in a linked list within the loop. It doesn't protect against other threads adding/deleting nodes to the list in parallel. We need to grab deferred_probe_mutex when traversing the deferred_probe_pending_list.
Cc: stable@vger.kernel.org Fixes: 25b4e70dcce9 ("driver core: allow stopping deferred probe after init") Signed-off-by: Saravana Kannan saravanak@google.com Link: https://lore.kernel.org/r/20210402040342.2944858-2-saravanak@google.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
diff --git a/drivers/base/dd.c b/drivers/base/dd.c index e2cf3b29123e..37a5e5f8b221 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -292,14 +292,16 @@ int driver_deferred_probe_check_state(struct device *dev)
static void deferred_probe_timeout_work_func(struct work_struct *work) {
struct device_private *private, *p;
struct device_private *p; driver_deferred_probe_timeout = 0; driver_deferred_probe_trigger(); flush_work(&deferred_probe_work);
list_for_each_entry_safe(private, p, &deferred_probe_pending_list, deferred_probe)dev_info(private->device, "deferred probe pending\n");
mutex_lock(&deferred_probe_mutex);list_for_each_entry(p, &deferred_probe_pending_list, deferred_probe)dev_info(p->device, "deferred probe pending\n");mutex_unlock(&deferred_probe_mutex); wake_up_all(&probe_timeout_waitqueue);} static DECLARE_DELAYED_WORK(deferred_probe_timeout_work, deferred_probe_timeout_work_func);