Re: [PATCH 1/2] TTY: pmac_zilog, check existence of ports in pmz_console_init()

From: Geert Uytterhoeven
Date: Tue Dec 24 2013 - 09:39:59 EST


On Fri, Nov 22, 2013 at 4:47 PM, Geert Uytterhoeven
<geert@xxxxxxxxxxxxxx> wrote:
> When booting a multi-platform m68k kernel on a non-Mac with "console=ttyS0"
> on the kernel command line, it crashes with:

Can we please get this in stable, too?

commit dc1dc2f8a5dd863bf2e79f338fc3ae29e99c683a

Thanks!

> 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@xxxxxxxxxxxxxx>
> Cc: Finn Thain <fthain@xxxxxxxxxxxxxxxxxxx>
> Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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