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Commit 077f58e4 authored by Sherry Sun's avatar Sherry Sun Committed by Greg Kroah-Hartman
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tty: serial: fsl_lpuart: fix potential bug when using both of_alias_get_id and ida_simple_get 



[ Upstream commit f398e0aa325c61fa20903833a5b534ecb8e6e418 ]

Now fsl_lpuart driver use both of_alias_get_id() and ida_simple_get() in
.probe(), which has the potential bug. For example, when remove the
lpuart7 alias in dts, of_alias_get_id() will return error, then call
ida_simple_get() to allocate the id 0 for lpuart7, this may confilct
with the lpuart4 which has alias 0.

    aliases {
	...
        serial0 = &lpuart4;
        serial1 = &lpuart5;
        serial2 = &lpuart6;
        serial3 = &lpuart7;
    }

So remove the ida_simple_get() in .probe(), return an error directly
when calling of_alias_get_id() fails, which is consistent with other
uart drivers behavior.

Fixes: 3bc3206e ("serial: fsl_lpuart: Remove the alias node dependence")
Signed-off-by: default avatarSherry Sun <sherry.sun@nxp.com>
Link: https://lore.kernel.org/r/20220321112211.8895-1-sherry.sun@nxp.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 7320308b

drivers/tty/serial/fsl_lpuart.c

+4 −20
Original line number Diff line number Diff line
@@ -233,8 +233,6 @@ 
/* IMX lpuart has four extra unused regs located at the beginning */

#define IMX_REG_OFF	0x10



static DEFINE_IDA(fsl_lpuart_ida);



enum lpuart_type {

	VF610_LPUART,

	LS1021A_LPUART,
@@ -269,7 +267,6 @@ struct lpuart_port { 
	int			rx_dma_rng_buf_len;

	unsigned int		dma_tx_nents;

	wait_queue_head_t	dma_wait;

	bool			id_allocated;

};



struct lpuart_soc_data {
@@ -2450,23 +2447,18 @@ static int lpuart_probe(struct platform_device *pdev) 


	ret = of_alias_get_id(np, "serial");

	if (ret < 0) {

		ret = ida_simple_get(&fsl_lpuart_ida, 0, UART_NR, GFP_KERNEL);

		if (ret < 0) {

			dev_err(&pdev->dev, "port line is full, add device failed\n");

		dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);

		return ret;

	}

		sport->id_allocated = true;

	}

	if (ret >= ARRAY_SIZE(lpuart_ports)) {

		dev_err(&pdev->dev, "serial%d out of range\n", ret);

		ret = -EINVAL;

		goto failed_out_of_range;

		return -EINVAL;

	}

	sport->port.line = ret;



	ret = lpuart_enable_clks(sport);

	if (ret)

		goto failed_clock_enable;

		return ret;

	sport->port.uartclk = lpuart_get_baud_clk_rate(sport);



	lpuart_ports[sport->port.line] = sport;
@@ -2516,10 +2508,6 @@ static int lpuart_probe(struct platform_device *pdev) 
failed_attach_port:

failed_irq_request:

	lpuart_disable_clks(sport);

failed_clock_enable:

failed_out_of_range:

	if (sport->id_allocated)

		ida_simple_remove(&fsl_lpuart_ida, sport->port.line);

	return ret;

}
@@ -2529,9 +2517,6 @@ static int lpuart_remove(struct platform_device *pdev) 


	uart_remove_one_port(&lpuart_reg, &sport->port);



	if (sport->id_allocated)

		ida_simple_remove(&fsl_lpuart_ida, sport->port.line);



	lpuart_disable_clks(sport);



	if (sport->dma_tx_chan)
@@ -2663,7 +2648,6 @@ static int __init lpuart_serial_init(void) 


static void __exit lpuart_serial_exit(void)

{

	ida_destroy(&fsl_lpuart_ida);

	platform_driver_unregister(&lpuart_driver);

	uart_unregister_driver(&lpuart_reg);

}