Skip to main content

Browse the archive

Revision dc280d93623927570da279e99393879dbbab39e7 authored by Thomas Gleixner on 21 December 2016, 19:19:49 UTC, committed by Thomas Gleixner on 25 December 2016, 09:47:42 UTC 
cpu/hotplug: Prevent overwriting of callbacks
 
Developers manage to overwrite states blindly without thought. That's fatal
and hard to debug. Add sanity checks to make it fail.

This requries to restructure the code so that the dynamic state allocation
happens in the same lock protected section as the actual store. Otherwise
the previous assignment of 'Reserved' to the name field would trigger the
overwrite check.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Link: http://lkml.kernel.org/r/20161221192111.675234535@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
1 parent 59fefd0
Raw File
pxa2xx_e740.c 
/*
 * Toshiba e740 PCMCIA specific routines.
 *
 * (c) 2004 Ian Molton <spyro@f2s.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/gpio.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>

#include <mach/eseries-gpio.h>

#include <asm/irq.h>
#include <asm/mach-types.h>

#include "soc_common.h"

static int e740_pcmcia_hw_init(struct soc_pcmcia_socket *skt)
{
	if (skt->nr == 0) {
		skt->stat[SOC_STAT_CD].gpio = GPIO_E740_PCMCIA_CD0;
		skt->stat[SOC_STAT_CD].name = "CF card detect";
		skt->stat[SOC_STAT_RDY].gpio = GPIO_E740_PCMCIA_RDY0;
		skt->stat[SOC_STAT_RDY].name = "CF ready";
	} else {
		skt->stat[SOC_STAT_CD].gpio = GPIO_E740_PCMCIA_CD1;
		skt->stat[SOC_STAT_CD].name = "Wifi switch";
		skt->stat[SOC_STAT_RDY].gpio = GPIO_E740_PCMCIA_RDY1;
		skt->stat[SOC_STAT_RDY].name = "Wifi ready";
	}

	return 0;
}

static void e740_pcmcia_socket_state(struct soc_pcmcia_socket *skt,
					struct pcmcia_state *state)
{
	state->vs_3v  = 1;
	state->vs_Xv  = 0;
}

static int e740_pcmcia_configure_socket(struct soc_pcmcia_socket *skt,
					const socket_state_t *state)
{
	if (state->flags & SS_RESET) {
		if (skt->nr == 0)
			gpio_set_value(GPIO_E740_PCMCIA_RST0, 1);
		else
			gpio_set_value(GPIO_E740_PCMCIA_RST1, 1);
	} else {
		if (skt->nr == 0)
			gpio_set_value(GPIO_E740_PCMCIA_RST0, 0);
		else
			gpio_set_value(GPIO_E740_PCMCIA_RST1, 0);
	}

	switch (state->Vcc) {
	case 0:	/* Socket off */
		if (skt->nr == 0)
			gpio_set_value(GPIO_E740_PCMCIA_PWR0, 0);
		else
			gpio_set_value(GPIO_E740_PCMCIA_PWR1, 1);
		break;
	case 50:
	case 33: /* socket on */
		if (skt->nr == 0)
			gpio_set_value(GPIO_E740_PCMCIA_PWR0, 1);
		else
			gpio_set_value(GPIO_E740_PCMCIA_PWR1, 0);
		break;
	default:
		printk(KERN_ERR "e740_cs: Unsupported Vcc: %d\n", state->Vcc);
	}

	return 0;
}

static struct pcmcia_low_level e740_pcmcia_ops = {
	.owner            = THIS_MODULE,
	.hw_init          = e740_pcmcia_hw_init,
	.socket_state     = e740_pcmcia_socket_state,
	.configure_socket = e740_pcmcia_configure_socket,
	.nr               = 2,
};

static struct platform_device *e740_pcmcia_device;

static int __init e740_pcmcia_init(void)
{
	int ret;

	if (!machine_is_e740())
		return -ENODEV;

	e740_pcmcia_device = platform_device_alloc("pxa2xx-pcmcia", -1);
	if (!e740_pcmcia_device)
		return -ENOMEM;

	ret = platform_device_add_data(e740_pcmcia_device, &e740_pcmcia_ops,
					sizeof(e740_pcmcia_ops));

	if (!ret)
		ret = platform_device_add(e740_pcmcia_device);

	if (ret)
		platform_device_put(e740_pcmcia_device);

	return ret;
}

static void __exit e740_pcmcia_exit(void)
{
	platform_device_unregister(e740_pcmcia_device);
}

module_init(e740_pcmcia_init);
module_exit(e740_pcmcia_exit);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Ian Molton <spyro@f2s.com>");
MODULE_ALIAS("platform:pxa2xx-pcmcia");
MODULE_DESCRIPTION("e740 PCMCIA platform support");
back to top