Commit d9b76796 authored by Abinash Singh's avatar Abinash Singh Committed by Greg Kroah-Hartman
Browse files

serial: 8250_platform: Reduce stack usage in serial8250_probe_acpi() 



The function serial8250_probe_acpi() in 8250_platform.c triggered a
    frame size warning:
drivers/tty/serial/8250/8250_platform.c: In function ‘serial8250_probe_acpi’:
drivers/tty/serial/8250/8250_platform.c:152:1: warning: the frame size of 1160 bytes is larger than 1024 bytes [-Wframe-larger-than=]

This patch reduces the stack usage by dynamically allocating the
`uart` structure using kzalloc(), rather than placing it on
the stack. This eliminates the overflow warning and improves kernel
robustness.

Signed-off-by: default avatarAbinash Singh <abinashsinghlalotra@gmail.com>
Reviewed-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20250806215134.4921-2-abinashsinghlalotra@gmail.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 672a37ba

drivers/tty/serial/8250/8250_platform.c

+15 −11
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ 
 */

#include <linux/acpi.h>

#include <linux/array_size.h>

#include <linux/cleanup.h>

#include <linux/io.h>

#include <linux/module.h>

#include <linux/moduleparam.h>
@@ -110,41 +111,44 @@ void __init serial8250_isa_init_ports(void) 
static int serial8250_probe_acpi(struct platform_device *pdev)

{

	struct device *dev = &pdev->dev;

	struct uart_8250_port uart = { };

	struct resource *regs;

	int ret, line;



	struct uart_8250_port *uart __free(kfree) = kzalloc(sizeof(*uart), GFP_KERNEL);

	if (!uart)

		return -ENOMEM;



	regs = platform_get_mem_or_io(pdev, 0);

	if (!regs)

		return dev_err_probe(dev, -EINVAL, "no registers defined\n");



	switch (resource_type(regs)) {

	case IORESOURCE_IO:

		uart.port.iobase = regs->start;

		uart->port.iobase = regs->start;

		break;

	case IORESOURCE_MEM:

		uart.port.mapbase = regs->start;

		uart.port.mapsize = resource_size(regs);

		uart.port.flags = UPF_IOREMAP;

		uart->port.mapbase = regs->start;

		uart->port.mapsize = resource_size(regs);

		uart->port.flags = UPF_IOREMAP;

		break;

	default:

		return -EINVAL;

	}



	/* default clock frequency */

	uart.port.uartclk = 1843200;

	uart.port.type = PORT_16550A;

	uart.port.dev = &pdev->dev;

	uart.port.flags |= UPF_SKIP_TEST | UPF_BOOT_AUTOCONF;

	uart->port.uartclk = 1843200;

	uart->port.type = PORT_16550A;

	uart->port.dev = &pdev->dev;

	uart->port.flags |= UPF_SKIP_TEST | UPF_BOOT_AUTOCONF;



	ret = uart_read_and_validate_port_properties(&uart.port);

	ret = uart_read_and_validate_port_properties(&uart->port);

	/* no interrupt -> fall back to polling */

	if (ret == -ENXIO)

		ret = 0;

	if (ret)

		return ret;



	line = serial8250_register_8250_port(&uart);

	line = serial8250_register_8250_port(uart);

	if (line < 0)

		return line;