• Geert Uytterhoeven's avatar
    TTY: pmac_zilog, check existence of ports in pmz_console_init() · dc1dc2f8
    Geert Uytterhoeven authored
    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: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
    Cc: Finn Thain <fthain@telegraphics.com.au>
    Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    dc1dc2f8
pmac_zilog.c 50.3 KB