Commit dc1dc2f8 authored Nov 22, 2013 by Geert Uytterhoeven Committed by Greg Kroah-Hartman Nov 25, 2013

TTY: pmac_zilog, check existence of ports in pmz_console_init()



When booting a multi-platform m68k kernel on a non-Mac with "console=ttyS0"
on the kernel command line, it crashes with:

Unable to handle kernel NULL pointer dereference at virtual address   (null)
Oops: 00000000
PC: [<0013ad28>] __pmz_startup+0x32/0x2a0
...
Call Trace: [<002c5d3e>] pmz_console_setup+0x64/0xe4

The normal tty driver doesn't crash, because init_pmz() checks
pmz_ports_count again after calling pmz_probe().

In the serial console initialization path, pmz_console_init() doesn't do
this, causing the driver to crash later.

Add a check for pmz_ports_count to fix this.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Finn Thain <fthain@telegraphics.com.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent c284ee2c

drivers/tty/serial/pmac_zilog.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -2052,6 +2052,9 @@ static int __init pmz_console_init(void)
		/* Probe ports */
		pmz_probe();

		if (pmz_ports_count == 0)
		return -ENODEV;

		/* TODO: Autoprobe console based on OF */
		/* pmz_console.index = i; */
		register_console(&pmz_console);