Messages in this thread Patch in this message | | | From | Bjorn Helgaas <> | Subject | [PATCH] serial console registration bugfix (2.6) | Date | Thu, 16 Oct 2003 10:58:56 -0600 |
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uart_set_options() can dereference a null pointer. This happens if you specify a console that hasn't previously been setup by early_serial_setup().
For example, on ia64, the HCDP typically tells us about line 0, so we calls early_serial_setup() for it. If the user specifies "console=ttyS3", we machine-check when trying to follow the uninitialized port->ops pointer.
It's not entirely clear to me whether we should return 0 or -ENODEV or something. The advantage of returning zero is that if the user specifies "console=ttyS0" and we just lack the HCDP, the console doesn't work as early as usual, but it does start working after the serial driver detects the port (though the baud/parity/etc from the command line are lost). Returning -ENODEV seems to prevent it from ever working.
Bjorn
===== drivers/serial/serial_core.c 1.72 vs edited ===== --- 1.72/drivers/serial/serial_core.c Mon Sep 29 18:35:33 2003 +++ edited/drivers/serial/serial_core.c Thu Oct 16 09:56:55 2003 @@ -1859,6 +1859,9 @@ if (flow == 'r') termios.c_cflag |= CRTSCTS; + if (!port->ops) + return 0; + port->ops->set_termios(port, &termios, NULL); co->cflag = termios.c_cflag; - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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