On Mon, Dec 29, 2014 at 01:33:37AM +0000, Ma, Xindong wrote: > > On Fri, Dec 26, 2014 at 03:45:25PM +0800, Leon Ma wrote: > > > We encountered following panic. The scenario is the process is exiting > > > and executing its task work. When closing dev node, the driver > > > triggers a firmware reload according to device status. Because task->fs is > > set to NULL in exit_fs(), panic happens. > > > Task work is a common interface, we should not limite the resource the > > user will utilize. > > > > Fix your driver. Forget ->fs being NULL; what will happen if your process > > is > > chrooted? > Thanks, But I'm not clear what is the limitation added to chroot env?
??? How about "the pathname of firmware apparently will be looked up inside the chroot"? Look, this is completely broken - you *can't* assume anything about the fs context in which ->release() will be run, period. It's not guaranteed to have anything in common with the environment in which the file had been opened, BTW - there might literally be not a single filesystem in common for both. This "reload firmware in ->release()" is absolutely braindead. The fact that it as much as dereferences current->fs demonstrates that it's broken. Don't do that. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
