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    Subject[PATCH resend 1/2] tty: omap-serial: fix division by zero
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    If the chosen baud rate is large enough (e.g. 3.5 megabaud), the
    calculated n values in serial_omap_is_baud_mode16() may become 0. This
    causes a division by zero when calculating the difference between
    calculated and desired baud rates. To prevent this, cap the n13 and n16
    values on 1.

    Division by zero in kernel.
    [<c00132e0>] (unwind_backtrace) from [<c00112ec>] (show_stack+0x10/0x14)
    [<c00112ec>] (show_stack) from [<c01ed7bc>] (Ldiv0+0x8/0x10)
    [<c01ed7bc>] (Ldiv0) from [<c023805c>] (serial_omap_baud_is_mode16+0x4c/0x68)
    [<c023805c>] (serial_omap_baud_is_mode16) from [<c02396b4>] (serial_omap_set_termios+0x90/0x8d8)
    [<c02396b4>] (serial_omap_set_termios) from [<c0230a0c>] (uart_change_speed+0xa4/0xa8)
    [<c0230a0c>] (uart_change_speed) from [<c0231798>] (uart_set_termios+0xa0/0x1fc)
    [<c0231798>] (uart_set_termios) from [<c022bb44>] (tty_set_termios+0x248/0x2c0)
    [<c022bb44>] (tty_set_termios) from [<c022c17c>] (set_termios+0x248/0x29c)
    [<c022c17c>] (set_termios) from [<c022c3e4>] (tty_mode_ioctl+0x1c8/0x4e8)
    [<c022c3e4>] (tty_mode_ioctl) from [<c0227e70>] (tty_ioctl+0xa94/0xb18)
    [<c0227e70>] (tty_ioctl) from [<c00cf45c>] (do_vfs_ioctl+0x4a0/0x560)
    [<c00cf45c>] (do_vfs_ioctl) from [<c00cf568>] (SyS_ioctl+0x4c/0x74)
    [<c00cf568>] (SyS_ioctl) from [<c000e480>] (ret_fast_syscall+0x0/0x30)

    Signed-off-by: Frans Klaver <frans.klaver@xsens.com>
    ---
    Resend to add stable@vger.kernel.org to CC. As far as I know, this applies to
    v3.9 and up.

    Thanks,
    Frans

    drivers/tty/serial/omap-serial.c | 12 ++++++++++--
    1 file changed, 10 insertions(+), 2 deletions(-)

    diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
    index d017cec..e454b7c 100644
    --- a/drivers/tty/serial/omap-serial.c
    +++ b/drivers/tty/serial/omap-serial.c
    @@ -254,8 +254,16 @@ serial_omap_baud_is_mode16(struct uart_port *port, unsigned int baud)
    {
    unsigned int n13 = port->uartclk / (13 * baud);
    unsigned int n16 = port->uartclk / (16 * baud);
    - int baudAbsDiff13 = baud - (port->uartclk / (13 * n13));
    - int baudAbsDiff16 = baud - (port->uartclk / (16 * n16));
    + int baudAbsDiff13;
    + int baudAbsDiff16;
    +
    + if (n13 == 0)
    + n13 = 1;
    + if (n16 == 0)
    + n16 = 1;
    +
    + baudAbsDiff13 = baud - (port->uartclk / (13 * n13));
    + baudAbsDiff16 = baud - (port->uartclk / (16 * n16));
    if (baudAbsDiff13 < 0)
    baudAbsDiff13 = -baudAbsDiff13;
    if (baudAbsDiff16 < 0)
    --
    2.1.0


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