Hi Lucas, On 03/06, Lucas De Marchi wrote: > > On Mon, Feb 25, 2013 at 3:08 PM, Oleg Nesterov <o...@redhat.com> wrote: > > > > So, I hope you will send v2. I'd suggest to split the fixes. 1/3 > > should create/export the new helpers, and 2-3 fix should call_modprobe() > > and call_usermodehelper_keys(). But this is up to you, I won't insist. > > I was implementing this today, but looking into call_modprobe(), it is > never called with UMH_NO_WAIT.
wait == T means UMH_WAIT_PROC, so we can't simply rely on CLONE_VFORK. But probably we can rely on sys_wait4. However, > @@ -98,12 +93,13 @@ static int call_modprobe(char *module_name, int wait) > argv[3] = module_name; /* check free_modprobe_argv() */ > argv[4] = NULL; > > - return call_usermodehelper_fns(modprobe_path, argv, envp, > - wait | UMH_KILLABLE, NULL, free_modprobe_argv, NULL); > + ret = call_usermodehelper(modprobe_path, argv, envp, > + wait | UMH_KILLABLE); > + kfree(module_name); Please note UMH_KILLABLE. call_usermodehelper() can be interrupted and even UMH_WAIT_EXEC case is not safe. If call_modprobe() is killed we can return while the workqueue thread still tries to clone/exec/etc. Oleg. -- 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/
