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linux/drivers/mmc/core/debugfs.c
Adrian Hunter f9f0da9881 mmc: block: Ensure that debugfs files are removed 
The card is not necessarily being removed, but the debugfs files must be
removed when the driver is removed, otherwise they will continue to exist
after unbinding the card from the driver. e.g.

  # echo "mmc1:0001" > /sys/bus/mmc/drivers/mmcblk/unbind
  # cat /sys/kernel/debug/mmc1/mmc1\:0001/ext_csd
  [  173.634584] BUG: unable to handle kernel NULL pointer dereference at 0000000000000050
  [  173.643356] IP: mmc_ext_csd_open+0x5e/0x170

A complication is that the debugfs_root may have already been removed, so
check for that too.

Fixes: 627c3ccfb4 ("mmc: debugfs: Move block debugfs into block module")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Cc: stable@vger.kernel.org # 4.14+
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2017-11-23 14:39:13 +01:00

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/*
* Debugfs support for hosts and cards
*
* Copyright (C) 2008 Atmel Corporation
*
* 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/moduleparam.h>
#include <linux/export.h>
#include <linux/debugfs.h>
#include <linux/fs.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/stat.h>
#include <linux/fault-inject.h>
#include <linux/mmc/card.h>
#include <linux/mmc/host.h>
#include "core.h"
#include "card.h"
#include "host.h"
#include "mmc_ops.h"
#ifdef CONFIG_FAIL_MMC_REQUEST
static DECLARE_FAULT_ATTR(fail_default_attr);
static char *fail_request;
module_param(fail_request, charp, 0);
#endif /* CONFIG_FAIL_MMC_REQUEST */
/* The debugfs functions are optimized away when CONFIG_DEBUG_FS isn't set. */
static int mmc_ios_show(struct seq_file *s, void *data)
{
static const char *vdd_str[] = {
[8] = "2.0",
[9] = "2.1",
[10] = "2.2",
[11] = "2.3",
[12] = "2.4",
[13] = "2.5",
[14] = "2.6",
[15] = "2.7",
[16] = "2.8",
[17] = "2.9",
[18] = "3.0",
[19] = "3.1",
[20] = "3.2",
[21] = "3.3",
[22] = "3.4",
[23] = "3.5",
[24] = "3.6",
};
struct mmc_host *host = s->private;
struct mmc_ios *ios = &host->ios;
const char *str;
seq_printf(s, "clock:\t\t%u Hz\n", ios->clock);
if (host->actual_clock)
seq_printf(s, "actual clock:\t%u Hz\n", host->actual_clock);
seq_printf(s, "vdd:\t\t%u ", ios->vdd);
if ((1 << ios->vdd) & MMC_VDD_165_195)
seq_printf(s, "(1.65 - 1.95 V)\n");
else if (ios->vdd < (ARRAY_SIZE(vdd_str) - 1)
&& vdd_str[ios->vdd] && vdd_str[ios->vdd + 1])
seq_printf(s, "(%s ~ %s V)\n", vdd_str[ios->vdd],
vdd_str[ios->vdd + 1]);
else
seq_printf(s, "(invalid)\n");
switch (ios->bus_mode) {
case MMC_BUSMODE_OPENDRAIN:
str = "open drain";
break;
case MMC_BUSMODE_PUSHPULL:
str = "push-pull";
break;
default:
str = "invalid";
break;
}
seq_printf(s, "bus mode:\t%u (%s)\n", ios->bus_mode, str);
switch (ios->chip_select) {
case MMC_CS_DONTCARE:
str = "don't care";
break;
case MMC_CS_HIGH:
str = "active high";
break;
case MMC_CS_LOW:
str = "active low";
break;
default:
str = "invalid";
break;
}
seq_printf(s, "chip select:\t%u (%s)\n", ios->chip_select, str);
switch (ios->power_mode) {
case MMC_POWER_OFF:
str = "off";
break;
case MMC_POWER_UP:
str = "up";
break;
case MMC_POWER_ON:
str = "on";
break;
default:
str = "invalid";
break;
}
seq_printf(s, "power mode:\t%u (%s)\n", ios->power_mode, str);
seq_printf(s, "bus width:\t%u (%u bits)\n",
ios->bus_width, 1 << ios->bus_width);
switch (ios->timing) {
case MMC_TIMING_LEGACY:
str = "legacy";
break;
case MMC_TIMING_MMC_HS:
str = "mmc high-speed";
break;
case MMC_TIMING_SD_HS:
str = "sd high-speed";
break;
case MMC_TIMING_UHS_SDR12:
str = "sd uhs SDR12";
break;
case MMC_TIMING_UHS_SDR25:
str = "sd uhs SDR25";
break;
case MMC_TIMING_UHS_SDR50:
str = "sd uhs SDR50";
break;
case MMC_TIMING_UHS_SDR104:
str = "sd uhs SDR104";
break;
case MMC_TIMING_UHS_DDR50:
str = "sd uhs DDR50";
break;
case MMC_TIMING_MMC_DDR52:
str = "mmc DDR52";
break;
case MMC_TIMING_MMC_HS200:
str = "mmc HS200";
break;
case MMC_TIMING_MMC_HS400:
str = mmc_card_hs400es(host->card) ?
"mmc HS400 enhanced strobe" : "mmc HS400";
break;
default:
str = "invalid";
break;
}
seq_printf(s, "timing spec:\t%u (%s)\n", ios->timing, str);
switch (ios->signal_voltage) {
case MMC_SIGNAL_VOLTAGE_330:
str = "3.30 V";
break;
case MMC_SIGNAL_VOLTAGE_180:
str = "1.80 V";
break;
case MMC_SIGNAL_VOLTAGE_120:
str = "1.20 V";
break;
default:
str = "invalid";
break;
}
seq_printf(s, "signal voltage:\t%u (%s)\n", ios->signal_voltage, str);
switch (ios->drv_type) {
case MMC_SET_DRIVER_TYPE_A:
str = "driver type A";
break;
case MMC_SET_DRIVER_TYPE_B:
str = "driver type B";
break;
case MMC_SET_DRIVER_TYPE_C:
str = "driver type C";
break;
case MMC_SET_DRIVER_TYPE_D:
str = "driver type D";
break;
default:
str = "invalid";
break;
}
seq_printf(s, "driver type:\t%u (%s)\n", ios->drv_type, str);
return 0;
}
static int mmc_ios_open(struct inode *inode, struct file *file)
{
return single_open(file, mmc_ios_show, inode->i_private);
}
static const struct file_operations mmc_ios_fops = {
.open = mmc_ios_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static int mmc_clock_opt_get(void *data, u64 *val)
{
struct mmc_host *host = data;
*val = host->ios.clock;
return 0;
}
static int mmc_clock_opt_set(void *data, u64 val)
{
struct mmc_host *host = data;
/* We need this check due to input value is u64 */
if (val != 0 && (val > host->f_max || val < host->f_min))
return -EINVAL;
mmc_claim_host(host);
mmc_set_clock(host, (unsigned int) val);
mmc_release_host(host);
return 0;
}
DEFINE_SIMPLE_ATTRIBUTE(mmc_clock_fops, mmc_clock_opt_get, mmc_clock_opt_set,
"%llu\n");
void mmc_add_host_debugfs(struct mmc_host *host)
{
struct dentry *root;
root = debugfs_create_dir(mmc_hostname(host), NULL);
if (IS_ERR(root))
/* Don't complain -- debugfs just isn't enabled */
return;
if (!root)
/* Complain -- debugfs is enabled, but it failed to
* create the directory. */
goto err_root;
host->debugfs_root = root;
if (!debugfs_create_file("ios", S_IRUSR, root, host, &mmc_ios_fops))
goto err_node;
if (!debugfs_create_file("clock", S_IRUSR | S_IWUSR, root, host,
&mmc_clock_fops))
goto err_node;
#ifdef CONFIG_FAIL_MMC_REQUEST
if (fail_request)
setup_fault_attr(&fail_default_attr, fail_request);
host->fail_mmc_request = fail_default_attr;
if (IS_ERR(fault_create_debugfs_attr("fail_mmc_request",
root,
&host->fail_mmc_request)))
goto err_node;
#endif
return;
err_node:
debugfs_remove_recursive(root);
host->debugfs_root = NULL;
err_root:
dev_err(&host->class_dev, "failed to initialize debugfs\n");
}
void mmc_remove_host_debugfs(struct mmc_host *host)
{
debugfs_remove_recursive(host->debugfs_root);
}
void mmc_add_card_debugfs(struct mmc_card *card)
{
struct mmc_host *host = card->host;
struct dentry *root;
if (!host->debugfs_root)
return;
root = debugfs_create_dir(mmc_card_id(card), host->debugfs_root);
if (IS_ERR(root))
/* Don't complain -- debugfs just isn't enabled */
return;
if (!root)
/* Complain -- debugfs is enabled, but it failed to
* create the directory. */
goto err;
card->debugfs_root = root;
if (!debugfs_create_x32("state", S_IRUSR, root, &card->state))
goto err;
return;
err:
debugfs_remove_recursive(root);
card->debugfs_root = NULL;
dev_err(&card->dev, "failed to initialize debugfs\n");
}
void mmc_remove_card_debugfs(struct mmc_card *card)
{
debugfs_remove_recursive(card->debugfs_root);
card->debugfs_root = NULL;
}
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