[PATCH AUTOSEL 4.4 19/35] hvsi: don't panic on tty_register_driver failure
From: Sasha Levin <sashal@kernel.org>
Date: 2021-09-09 13:26:09
Also in:
linuxppc-dev, lkml
Subsystem:
hypervisor virtual console driver, the rest, tty layer and serial drivers · Maintainers:
Linus Torvalds, Greg Kroah-Hartman, Jiri Slaby
From: Jiri Slaby <redacted> [ Upstream commit 7ccbdcc4d08a6d7041e4849219bbb12ffa45db4c ] The alloc_tty_driver failure is handled gracefully in hvsi_init. But tty_register_driver is not. panic is called if that one fails. So handle the failure of tty_register_driver gracefully too. This will keep at least the console functional as it was enabled earlier by console_initcall in hvsi_console_init. Instead of shooting down the whole system. This means, we disable interrupts and restore hvsi_wait back to poll_for_state(). Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Jiri Slaby <redacted> Link: https://lore.kernel.org/r/20210723074317.32690-3-jslaby@suse.cz (local) Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> --- drivers/tty/hvc/hvsi.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-)
diff --git a/drivers/tty/hvc/hvsi.c b/drivers/tty/hvc/hvsi.c
index a75146f600cb..3e29f5f0d4ca 100644
--- a/drivers/tty/hvc/hvsi.c
+++ b/drivers/tty/hvc/hvsi.c@@ -1051,7 +1051,7 @@ static const struct tty_operations hvsi_ops = { static int __init hvsi_init(void) { - int i; + int i, ret; hvsi_driver = alloc_tty_driver(hvsi_count); if (!hvsi_driver)
@@ -1082,12 +1082,25 @@ static int __init hvsi_init(void) } hvsi_wait = wait_for_state; /* irqs active now */ - if (tty_register_driver(hvsi_driver)) - panic("Couldn't register hvsi console driver\n"); + ret = tty_register_driver(hvsi_driver); + if (ret) { + pr_err("Couldn't register hvsi console driver\n"); + goto err_free_irq; + } printk(KERN_DEBUG "HVSI: registered %i devices\n", hvsi_count); return 0; +err_free_irq: + hvsi_wait = poll_for_state; + for (i = 0; i < hvsi_count; i++) { + struct hvsi_struct *hp = &hvsi_ports[i]; + + free_irq(hp->virq, hp); + } + tty_driver_kref_put(hvsi_driver); + + return ret; } device_initcall(hvsi_init);
--
2.30.2