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* [PATCH 1/2] TTY: pmac_zilog, check existence of ports in pmz_console_init()
@ 2013-11-22 15:47 Geert Uytterhoeven
  2013-11-22 15:47 ` [PATCH 2/2] TTY: amiserial, add missing platform check Geert Uytterhoeven
  2013-12-24 14:39 ` [PATCH 1/2] TTY: pmac_zilog, check existence of ports in pmz_console_init() Geert Uytterhoeven
  0 siblings, 2 replies; 6+ messages in thread
From: Geert Uytterhoeven @ 2013-11-22 15:47 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Jiri Slaby
  Cc: linux-serial, linux-m68k, linux-kernel, Geert Uytterhoeven,
	Finn Thain, Benjamin Herrenschmidt

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>
---
 drivers/tty/serial/pmac_zilog.c |    3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/tty/serial/pmac_zilog.c b/drivers/tty/serial/pmac_zilog.c
index 481b781b26e3..e9d420ff3931 100644
--- a/drivers/tty/serial/pmac_zilog.c
+++ b/drivers/tty/serial/pmac_zilog.c
@@ -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);
-- 
1.7.9.5

^ permalink raw reply related	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2014-03-30 16:46 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2013-11-22 15:47 [PATCH 1/2] TTY: pmac_zilog, check existence of ports in pmz_console_init() Geert Uytterhoeven
2013-11-22 15:47 ` [PATCH 2/2] TTY: amiserial, add missing platform check Geert Uytterhoeven
2013-12-24 14:39 ` [PATCH 1/2] TTY: pmac_zilog, check existence of ports in pmz_console_init() Geert Uytterhoeven
2013-12-31  5:19   ` Greg Kroah-Hartman
2014-01-06 14:43   ` Luis Henriques
2014-03-30 16:46   ` Ben Hutchings

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