linux_dsm_epyc7002/drivers/net/phy/mdio-mux-gpio.c
Kees Cook 68cc444dab mdio-mux-gpio: Remove VLA usage
In the quest to remove all stack VLA usage from the kernel[1], this
allocates the values buffer during the callback instead of putting it
on the stack.

[1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com

Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-26 23:24:07 +09:00

110 lines
2.4 KiB
C

/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2011, 2012 Cavium, Inc.
*/
#include <linux/platform_device.h>
#include <linux/device.h>
#include <linux/of_mdio.h>
#include <linux/module.h>
#include <linux/phy.h>
#include <linux/mdio-mux.h>
#include <linux/gpio/consumer.h>
#define DRV_VERSION "1.1"
#define DRV_DESCRIPTION "GPIO controlled MDIO bus multiplexer driver"
struct mdio_mux_gpio_state {
struct gpio_descs *gpios;
void *mux_handle;
int values[];
};
static int mdio_mux_gpio_switch_fn(int current_child, int desired_child,
void *data)
{
struct mdio_mux_gpio_state *s = data;
unsigned int n;
if (current_child == desired_child)
return 0;
for (n = 0; n < s->gpios->ndescs; n++)
s->values[n] = (desired_child >> n) & 1;
gpiod_set_array_value_cansleep(s->gpios->ndescs, s->gpios->desc,
s->values);
return 0;
}
static int mdio_mux_gpio_probe(struct platform_device *pdev)
{
struct mdio_mux_gpio_state *s;
struct gpio_descs *gpios;
int r;
gpios = gpiod_get_array(&pdev->dev, NULL, GPIOD_OUT_LOW);
if (IS_ERR(gpios))
return PTR_ERR(gpios);
s = devm_kzalloc(&pdev->dev, struct_size(s, values, gpios->ndescs),
GFP_KERNEL);
if (!s) {
gpiod_put_array(gpios);
return -ENOMEM;
}
s->gpios = gpios;
r = mdio_mux_init(&pdev->dev, pdev->dev.of_node,
mdio_mux_gpio_switch_fn, &s->mux_handle, s, NULL);
if (r != 0) {
gpiod_put_array(s->gpios);
return r;
}
pdev->dev.platform_data = s;
return 0;
}
static int mdio_mux_gpio_remove(struct platform_device *pdev)
{
struct mdio_mux_gpio_state *s = dev_get_platdata(&pdev->dev);
mdio_mux_uninit(s->mux_handle);
gpiod_put_array(s->gpios);
return 0;
}
static const struct of_device_id mdio_mux_gpio_match[] = {
{
.compatible = "mdio-mux-gpio",
},
{
/* Legacy compatible property. */
.compatible = "cavium,mdio-mux-sn74cbtlv3253",
},
{},
};
MODULE_DEVICE_TABLE(of, mdio_mux_gpio_match);
static struct platform_driver mdio_mux_gpio_driver = {
.driver = {
.name = "mdio-mux-gpio",
.of_match_table = mdio_mux_gpio_match,
},
.probe = mdio_mux_gpio_probe,
.remove = mdio_mux_gpio_remove,
};
module_platform_driver(mdio_mux_gpio_driver);
MODULE_DESCRIPTION(DRV_DESCRIPTION);
MODULE_VERSION(DRV_VERSION);
MODULE_AUTHOR("David Daney");
MODULE_LICENSE("GPL");