From: Jiri Slaby Date: Mon, 5 Mar 2012 13:52:52 +0000 (+0100) Subject: TTY: pdc_cons, fix open vs pdc_console_tty_driver race X-Git-Tag: firefly_0821_release~3680^2~3346^2~23 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=0b479d54ae7b79f62f09ef977c2228e579924d38;p=firefly-linux-kernel-4.4.55.git TTY: pdc_cons, fix open vs pdc_console_tty_driver race Assign the pointer to pdc_console_tty_driver (a tty_driver) earlier. Otherwise the timer may dereference NULL. Signed-off-by: Jiri Slaby Cc: Kyle McMartin Cc: Helge Deller Cc: "James E.J. Bottomley" Signed-off-by: Greg Kroah-Hartman --- diff --git a/arch/parisc/kernel/pdc_cons.c b/arch/parisc/kernel/pdc_cons.c index 8ad05215d4b1..d14e20fc60df 100644 --- a/arch/parisc/kernel/pdc_cons.c +++ b/arch/parisc/kernel/pdc_cons.c @@ -160,9 +160,7 @@ static void pdc_console_poll(unsigned long unused) static int __init pdc_console_tty_driver_init(void) { - int err; - struct tty_driver *drv; /* Check if the console driver is still registered. * It is unregistered if the pdc console was not selected as the @@ -184,28 +182,27 @@ static int __init pdc_console_tty_driver_init(void) printk(KERN_INFO "The PDC console driver is still registered, removing CON_BOOT flag\n"); pdc_cons.flags &= ~CON_BOOT; - drv = alloc_tty_driver(1); + pdc_console_tty_driver = alloc_tty_driver(1); - if (!drv) + if (!pdc_console_tty_driver) return -ENOMEM; - drv->driver_name = "pdc_cons"; - drv->name = "ttyB"; - drv->major = MUX_MAJOR; - drv->minor_start = 0; - drv->type = TTY_DRIVER_TYPE_SYSTEM; - drv->init_termios = tty_std_termios; - drv->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_RESET_TERMIOS; - tty_set_operations(drv, &pdc_console_tty_ops); - - err = tty_register_driver(drv); + pdc_console_tty_driver->driver_name = "pdc_cons"; + pdc_console_tty_driver->name = "ttyB"; + pdc_console_tty_driver->major = MUX_MAJOR; + pdc_console_tty_driver->minor_start = 0; + pdc_console_tty_driver->type = TTY_DRIVER_TYPE_SYSTEM; + pdc_console_tty_driver->init_termios = tty_std_termios; + pdc_console_tty_driver->flags = TTY_DRIVER_REAL_RAW | + TTY_DRIVER_RESET_TERMIOS; + tty_set_operations(pdc_console_tty_driver, &pdc_console_tty_ops); + + err = tty_register_driver(pdc_console_tty_driver); if (err) { printk(KERN_ERR "Unable to register the PDC console TTY driver\n"); return err; } - pdc_console_tty_driver = drv; - return 0; }