On Wed, May 02, 2018 at 05:38:49PM -0500, Wenwen Wang wrote: > At the end of atomisp_subdev_set_selection(), the function > atomisp_subdev_get_rect() is invoked to get the pointer to v4l2_rect. Since > this function may return a NULL pointer, it is firstly invoked to check > the returned pointer. If the returned pointer is not NULL, then the > function is invoked again to obtain the pointer and the memory content > at the location of the returned pointer is copied to the memory location of > r. In most cases, the pointers returned by the two invocations are same. > However, given that the pointer returned by the function > atomisp_subdev_get_rect() is not a constant, it is possible that the two > invocations return two different pointers. For example, another thread may > race to modify the related pointers during the two invocations. You're assuming a very serious race condition exists. > In that > case, even if the first returned pointer is not null, the second returned > pointer might be null, which will cause issues such as null pointer > dereference. And then complaining that if a really serious bug exists then this very minor bug would exist too... If there were really a race condition like that then we'd want to fix it instead. In other words, this is not a real life bug fix. But it would be fine as a readability or static checker fix so that's fine. regards, dan carpenter
