From 0524513afe45a4a79f418c0377160b7712cab78a Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Fri, 23 Jul 2021 09:43:12 +0200 Subject: tty: don't store semi-state into tty drivers When a tty driver pointer is used as a return value of struct console's device() hook, don't store a semi-state into global variable which holds the tty driver. It could mean console::device() would return a bogus value. This is important esp. after the next patch where we switch from alloc_tty_driver to tty_alloc_driver. tty_alloc_driver returns ERR_PTR in case of error and that might have unexpected results as the code doesn't expect this. Cc: Geert Uytterhoeven Cc: "James E.J. Bottomley" Cc: Helge Deller Cc: Chris Zankel Cc: Max Filippov Cc: Laurentiu Tudor Cc: Felipe Balbi Reviewed-by: Max Filippov Acked-by: Helge Deller # parisc Signed-off-by: Jiri Slaby Link: https://lore.kernel.org/r/20210723074317.32690-4-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman --- drivers/tty/hvc/hvsi.c | 35 +++++++++++++++++++---------------- 1 file changed, 19 insertions(+), 16 deletions(-) (limited to 'drivers/tty/hvc') diff --git a/drivers/tty/hvc/hvsi.c b/drivers/tty/hvc/hvsi.c index f0bc8e780051..bfde7b1936a5 100644 --- a/drivers/tty/hvc/hvsi.c +++ b/drivers/tty/hvc/hvsi.c @@ -1038,29 +1038,30 @@ static const struct tty_operations hvsi_ops = { static int __init hvsi_init(void) { + struct tty_driver *driver; int i, ret; - hvsi_driver = alloc_tty_driver(hvsi_count); - if (!hvsi_driver) + driver = alloc_tty_driver(hvsi_count); + if (!driver) return -ENOMEM; - hvsi_driver->driver_name = "hvsi"; - hvsi_driver->name = "hvsi"; - hvsi_driver->major = HVSI_MAJOR; - hvsi_driver->minor_start = HVSI_MINOR; - hvsi_driver->type = TTY_DRIVER_TYPE_SYSTEM; - hvsi_driver->init_termios = tty_std_termios; - hvsi_driver->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL; - hvsi_driver->init_termios.c_ispeed = 9600; - hvsi_driver->init_termios.c_ospeed = 9600; - hvsi_driver->flags = TTY_DRIVER_REAL_RAW; - tty_set_operations(hvsi_driver, &hvsi_ops); + driver->driver_name = "hvsi"; + driver->name = "hvsi"; + driver->major = HVSI_MAJOR; + driver->minor_start = HVSI_MINOR; + driver->type = TTY_DRIVER_TYPE_SYSTEM; + driver->init_termios = tty_std_termios; + driver->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL; + driver->init_termios.c_ispeed = 9600; + driver->init_termios.c_ospeed = 9600; + driver->flags = TTY_DRIVER_REAL_RAW; + tty_set_operations(driver, &hvsi_ops); for (i=0; i < hvsi_count; i++) { struct hvsi_struct *hp = &hvsi_ports[i]; int ret = 1; - tty_port_link_device(&hp->port, hvsi_driver, i); + tty_port_link_device(&hp->port, driver, i); ret = request_irq(hp->virq, hvsi_interrupt, 0, "hvsi", hp); if (ret) @@ -1069,12 +1070,14 @@ static int __init hvsi_init(void) } hvsi_wait = wait_for_state; /* irqs active now */ - ret = tty_register_driver(hvsi_driver); + ret = tty_register_driver(driver); if (ret) { pr_err("Couldn't register hvsi console driver\n"); goto err_free_irq; } + hvsi_driver = driver; + printk(KERN_DEBUG "HVSI: registered %i devices\n", hvsi_count); return 0; @@ -1085,7 +1088,7 @@ err_free_irq: free_irq(hp->virq, hp); } - tty_driver_kref_put(hvsi_driver); + tty_driver_kref_put(driver); return ret; } -- cgit v1.2.3