A use-after-free scenario is possible where one thread in
gk20a_free_error_notifiers() is trying to free the error
notifier and another thread in gk20a_set_error_notifier()
is still using the error notifier
Fix this by introducing mutex error_notifier_mutex for
error notifier accesses
Take mutex in gk20a_free_error_notifiers() and in
gk20a_set_error_notifier() before accessing notifier
In gk20a_init_error_notifier(), set the pointer
ch->error_notifier_ref inside the mutex and only
after notifier is completely initialized
Bug 1824788
Change-Id: I47e1ab57d54f391799f5a0999840b663fd34585f
Signed-off-by: Deepak Nibade <dnibade@nvidia.com>
Reviewed-on: http://git-master/r/1233988
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>