2
0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-15 08:44:14 +08:00
linux-next/drivers/power/power_supply_sysfs.c
Krzysztof Kozlowski 5c6e3a97e9 power_supply: sysfs: Bring back write to writeable properties
The fix for NULL pointer exception related to calling uevent for not
finished probe caused to set all writeable properties as non-writeable.
This was caused by checking if property is writeable before the initial
increase of power supply usage counter and in the same time using
wrapper over property_is_writeable(). The wrapper returns ENODEV if the
usage counter is still 0.

The call trace looked like:
  device probe:
    power_supply_register()
      use_cnt = 0;
      device_add()
        create sysfs entries
          power_supply_attr_is_visible()
            power_supply_property_is_writeable()
              if (use_cnt == 0) return -ENODEV;
      use_cnt++;

Replace the usage of wrapper with direct call to property_is_writeable()
from driver. This should be safe call during device probe because
implementations of this callback just return 0/1 for different
properties and they do not access any of the driver's internal data.

Fixes: 8e59c7f234 ("power_supply: Fix NULL pointer dereference during bq27x00_battery probe")
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
2015-06-10 16:10:59 +02:00

337 lines
9.1 KiB
C

/*
* Sysfs interface for the universal power supply monitor class
*
* Copyright © 2007 David Woodhouse <dwmw2@infradead.org>
* Copyright © 2007 Anton Vorontsov <cbou@mail.ru>
* Copyright © 2004 Szabolcs Gyurko
* Copyright © 2003 Ian Molton <spyro@f2s.com>
*
* Modified: 2004, Oct Szabolcs Gyurko
*
* You may use this code as per GPL version 2
*/
#include <linux/ctype.h>
#include <linux/device.h>
#include <linux/power_supply.h>
#include <linux/slab.h>
#include <linux/stat.h>
#include "power_supply.h"
/*
* This is because the name "current" breaks the device attr macro.
* The "current" word resolves to "(get_current())" so instead of
* "current" "(get_current())" appears in the sysfs.
*
* The source of this definition is the device.h which calls __ATTR
* macro in sysfs.h which calls the __stringify macro.
*
* Only modification that the name is not tried to be resolved
* (as a macro let's say).
*/
#define POWER_SUPPLY_ATTR(_name) \
{ \
.attr = { .name = #_name }, \
.show = power_supply_show_property, \
.store = power_supply_store_property, \
}
static struct device_attribute power_supply_attrs[];
static ssize_t power_supply_show_property(struct device *dev,
struct device_attribute *attr,
char *buf) {
static char *type_text[] = {
"Unknown", "Battery", "UPS", "Mains", "USB",
"USB_DCP", "USB_CDP", "USB_ACA"
};
static char *status_text[] = {
"Unknown", "Charging", "Discharging", "Not charging", "Full"
};
static char *charge_type[] = {
"Unknown", "N/A", "Trickle", "Fast"
};
static char *health_text[] = {
"Unknown", "Good", "Overheat", "Dead", "Over voltage",
"Unspecified failure", "Cold", "Watchdog timer expire",
"Safety timer expire"
};
static char *technology_text[] = {
"Unknown", "NiMH", "Li-ion", "Li-poly", "LiFe", "NiCd",
"LiMn"
};
static char *capacity_level_text[] = {
"Unknown", "Critical", "Low", "Normal", "High", "Full"
};
static char *scope_text[] = {
"Unknown", "System", "Device"
};
ssize_t ret = 0;
struct power_supply *psy = dev_get_drvdata(dev);
const ptrdiff_t off = attr - power_supply_attrs;
union power_supply_propval value;
if (off == POWER_SUPPLY_PROP_TYPE) {
value.intval = psy->desc->type;
} else {
ret = power_supply_get_property(psy, off, &value);
if (ret < 0) {
if (ret == -ENODATA)
dev_dbg(dev, "driver has no data for `%s' property\n",
attr->attr.name);
else if (ret != -ENODEV)
dev_err(dev, "driver failed to report `%s' property: %zd\n",
attr->attr.name, ret);
return ret;
}
}
if (off == POWER_SUPPLY_PROP_STATUS)
return sprintf(buf, "%s\n", status_text[value.intval]);
else if (off == POWER_SUPPLY_PROP_CHARGE_TYPE)
return sprintf(buf, "%s\n", charge_type[value.intval]);
else if (off == POWER_SUPPLY_PROP_HEALTH)
return sprintf(buf, "%s\n", health_text[value.intval]);
else if (off == POWER_SUPPLY_PROP_TECHNOLOGY)
return sprintf(buf, "%s\n", technology_text[value.intval]);
else if (off == POWER_SUPPLY_PROP_CAPACITY_LEVEL)
return sprintf(buf, "%s\n", capacity_level_text[value.intval]);
else if (off == POWER_SUPPLY_PROP_TYPE)
return sprintf(buf, "%s\n", type_text[value.intval]);
else if (off == POWER_SUPPLY_PROP_SCOPE)
return sprintf(buf, "%s\n", scope_text[value.intval]);
else if (off >= POWER_SUPPLY_PROP_MODEL_NAME)
return sprintf(buf, "%s\n", value.strval);
return sprintf(buf, "%d\n", value.intval);
}
static ssize_t power_supply_store_property(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count) {
ssize_t ret;
struct power_supply *psy = dev_get_drvdata(dev);
const ptrdiff_t off = attr - power_supply_attrs;
union power_supply_propval value;
long long_val;
/* TODO: support other types than int */
ret = kstrtol(buf, 10, &long_val);
if (ret < 0)
return ret;
value.intval = long_val;
ret = power_supply_set_property(psy, off, &value);
if (ret < 0)
return ret;
return count;
}
/* Must be in the same order as POWER_SUPPLY_PROP_* */
static struct device_attribute power_supply_attrs[] = {
/* Properties of type `int' */
POWER_SUPPLY_ATTR(status),
POWER_SUPPLY_ATTR(charge_type),
POWER_SUPPLY_ATTR(health),
POWER_SUPPLY_ATTR(present),
POWER_SUPPLY_ATTR(online),
POWER_SUPPLY_ATTR(authentic),
POWER_SUPPLY_ATTR(technology),
POWER_SUPPLY_ATTR(cycle_count),
POWER_SUPPLY_ATTR(voltage_max),
POWER_SUPPLY_ATTR(voltage_min),
POWER_SUPPLY_ATTR(voltage_max_design),
POWER_SUPPLY_ATTR(voltage_min_design),
POWER_SUPPLY_ATTR(voltage_now),
POWER_SUPPLY_ATTR(voltage_avg),
POWER_SUPPLY_ATTR(voltage_ocv),
POWER_SUPPLY_ATTR(voltage_boot),
POWER_SUPPLY_ATTR(current_max),
POWER_SUPPLY_ATTR(current_now),
POWER_SUPPLY_ATTR(current_avg),
POWER_SUPPLY_ATTR(current_boot),
POWER_SUPPLY_ATTR(power_now),
POWER_SUPPLY_ATTR(power_avg),
POWER_SUPPLY_ATTR(charge_full_design),
POWER_SUPPLY_ATTR(charge_empty_design),
POWER_SUPPLY_ATTR(charge_full),
POWER_SUPPLY_ATTR(charge_empty),
POWER_SUPPLY_ATTR(charge_now),
POWER_SUPPLY_ATTR(charge_avg),
POWER_SUPPLY_ATTR(charge_counter),
POWER_SUPPLY_ATTR(constant_charge_current),
POWER_SUPPLY_ATTR(constant_charge_current_max),
POWER_SUPPLY_ATTR(constant_charge_voltage),
POWER_SUPPLY_ATTR(constant_charge_voltage_max),
POWER_SUPPLY_ATTR(charge_control_limit),
POWER_SUPPLY_ATTR(charge_control_limit_max),
POWER_SUPPLY_ATTR(input_current_limit),
POWER_SUPPLY_ATTR(energy_full_design),
POWER_SUPPLY_ATTR(energy_empty_design),
POWER_SUPPLY_ATTR(energy_full),
POWER_SUPPLY_ATTR(energy_empty),
POWER_SUPPLY_ATTR(energy_now),
POWER_SUPPLY_ATTR(energy_avg),
POWER_SUPPLY_ATTR(capacity),
POWER_SUPPLY_ATTR(capacity_alert_min),
POWER_SUPPLY_ATTR(capacity_alert_max),
POWER_SUPPLY_ATTR(capacity_level),
POWER_SUPPLY_ATTR(temp),
POWER_SUPPLY_ATTR(temp_max),
POWER_SUPPLY_ATTR(temp_min),
POWER_SUPPLY_ATTR(temp_alert_min),
POWER_SUPPLY_ATTR(temp_alert_max),
POWER_SUPPLY_ATTR(temp_ambient),
POWER_SUPPLY_ATTR(temp_ambient_alert_min),
POWER_SUPPLY_ATTR(temp_ambient_alert_max),
POWER_SUPPLY_ATTR(time_to_empty_now),
POWER_SUPPLY_ATTR(time_to_empty_avg),
POWER_SUPPLY_ATTR(time_to_full_now),
POWER_SUPPLY_ATTR(time_to_full_avg),
POWER_SUPPLY_ATTR(type),
POWER_SUPPLY_ATTR(scope),
POWER_SUPPLY_ATTR(charge_term_current),
POWER_SUPPLY_ATTR(calibrate),
/* Properties of type `const char *' */
POWER_SUPPLY_ATTR(model_name),
POWER_SUPPLY_ATTR(manufacturer),
POWER_SUPPLY_ATTR(serial_number),
};
static struct attribute *
__power_supply_attrs[ARRAY_SIZE(power_supply_attrs) + 1];
static umode_t power_supply_attr_is_visible(struct kobject *kobj,
struct attribute *attr,
int attrno)
{
struct device *dev = container_of(kobj, struct device, kobj);
struct power_supply *psy = dev_get_drvdata(dev);
umode_t mode = S_IRUSR | S_IRGRP | S_IROTH;
int i;
if (attrno == POWER_SUPPLY_PROP_TYPE)
return mode;
for (i = 0; i < psy->desc->num_properties; i++) {
int property = psy->desc->properties[i];
if (property == attrno) {
if (psy->desc->property_is_writeable &&
psy->desc->property_is_writeable(psy, property) > 0)
mode |= S_IWUSR;
return mode;
}
}
return 0;
}
static struct attribute_group power_supply_attr_group = {
.attrs = __power_supply_attrs,
.is_visible = power_supply_attr_is_visible,
};
static const struct attribute_group *power_supply_attr_groups[] = {
&power_supply_attr_group,
NULL,
};
void power_supply_init_attrs(struct device_type *dev_type)
{
int i;
dev_type->groups = power_supply_attr_groups;
for (i = 0; i < ARRAY_SIZE(power_supply_attrs); i++)
__power_supply_attrs[i] = &power_supply_attrs[i].attr;
}
static char *kstruprdup(const char *str, gfp_t gfp)
{
char *ret, *ustr;
ustr = ret = kmalloc(strlen(str) + 1, gfp);
if (!ret)
return NULL;
while (*str)
*ustr++ = toupper(*str++);
*ustr = 0;
return ret;
}
int power_supply_uevent(struct device *dev, struct kobj_uevent_env *env)
{
struct power_supply *psy = dev_get_drvdata(dev);
int ret = 0, j;
char *prop_buf;
char *attrname;
dev_dbg(dev, "uevent\n");
if (!psy || !psy->desc) {
dev_dbg(dev, "No power supply yet\n");
return ret;
}
dev_dbg(dev, "POWER_SUPPLY_NAME=%s\n", psy->desc->name);
ret = add_uevent_var(env, "POWER_SUPPLY_NAME=%s", psy->desc->name);
if (ret)
return ret;
prop_buf = (char *)get_zeroed_page(GFP_KERNEL);
if (!prop_buf)
return -ENOMEM;
for (j = 0; j < psy->desc->num_properties; j++) {
struct device_attribute *attr;
char *line;
attr = &power_supply_attrs[psy->desc->properties[j]];
ret = power_supply_show_property(dev, attr, prop_buf);
if (ret == -ENODEV || ret == -ENODATA) {
/* When a battery is absent, we expect -ENODEV. Don't abort;
send the uevent with at least the the PRESENT=0 property */
ret = 0;
continue;
}
if (ret < 0)
goto out;
line = strchr(prop_buf, '\n');
if (line)
*line = 0;
attrname = kstruprdup(attr->attr.name, GFP_KERNEL);
if (!attrname) {
ret = -ENOMEM;
goto out;
}
dev_dbg(dev, "prop %s=%s\n", attrname, prop_buf);
ret = add_uevent_var(env, "POWER_SUPPLY_%s=%s", attrname, prop_buf);
kfree(attrname);
if (ret)
goto out;
}
out:
free_page((unsigned long)prop_buf);
return ret;
}