On 12/28/2014 07:58 PM, Ma, Xindong wrote: >> >> On 12/26, 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. >> >> I think this should be fixed somewhere else... > Yes, for this panic, I also think driver is not perfect and need a fix. But > kernel should not add the limitation like this... >> >>> Task work is a common interface, we should not limite the resource the >> user will utilize. >> >> Exactly. And note that with this patch exit_mm()..disassociate_ctty() paths >> can't use task works. > I don't get this. Currently disassociate_ctty() is also called after > exit_mm() and exit_task_work(). My patch didn't change this.
?? 742- if (group_dead) 743: disassociate_ctty(1); 744- exit_task_namespaces(tsk); 745- exit_task_work(tsk); 746- exit_thread(); >> Not to mention that this patch moves exit_files() up, even before exit_mm(), >> without any explanation. > Moving exit_files() up is because exit_files() closes files and add tasks to > task works. >> >> Add Al. May be we can move exit_fs() down after exit_task_work(), I dunno, >> but to me it would be better to change the driver. >> > I'm OK with this suggestion to fix this issue. I'm not sure whether in the > future task work users will access other resources and expose other issues. > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
