| From | Greg Kroah-Hartman <> | Subject | [PATCH 3.10 005/129] TTY: pmac_zilog, check existence of ports in pmz_console_init() | Date | Mon, 6 Jan 2014 14:37:14 -0800 |
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3.10-stable review patch. If anyone has any objections, please let me know.
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From: Geert Uytterhoeven <geert@linux-m68k.org>
commit dc1dc2f8a5dd863bf2e79f338fc3ae29e99c683a upstream.
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>
--- drivers/tty/serial/pmac_zilog.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/drivers/tty/serial/pmac_zilog.c +++ b/drivers/tty/serial/pmac_zilog.c @@ -2051,6 +2051,9 @@ 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);
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