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>
diff --git a/drivers/tty/serial/pmac_zilog.c b/drivers/tty/serial/pmac_zilog.c
index 481b781..e9d420f 100644
--- a/drivers/tty/serial/pmac_zilog.c
+++ b/drivers/tty/serial/pmac_zilog.c
@@ -2052,6 +2052,9 @@
/* 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);