Make the device attribute list used to create sysfs attributes more
robust by decoupling the list order from order of the enum defined in
power_supply.h. This is done by using a designated initializer in the
POWER_SUPPLY_ATTR macro.

Signed-off-by: Mathew King <math...@chromium.org>
---
v2: - Don't create attributes for unlisted properties
    - Use a char array for lower case name so no allocations needed
      in init
---
 drivers/power/supply/power_supply_sysfs.c | 260 +++++++++++-----------
 1 file changed, 132 insertions(+), 128 deletions(-)

diff --git a/drivers/power/supply/power_supply_sysfs.c 
b/drivers/power/supply/power_supply_sysfs.c
index f37ad4eae60b..69be80b321ea 100644
--- a/drivers/power/supply/power_supply_sysfs.c
+++ b/drivers/power/supply/power_supply_sysfs.c
@@ -18,26 +18,20 @@
 
 #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 MAX_PROP_NAME_LEN 30
 
-#define POWER_SUPPLY_ATTR(_name)                                       \
-{                                                                      \
-       .attr = { .name = #_name },                                     \
-       .show = power_supply_show_property,                             \
-       .store = power_supply_store_property,                           \
-}
+struct power_supply_attr {
+       const char *prop_name;
+       char attr_name[MAX_PROP_NAME_LEN + 1];
+       struct device_attribute dev_attr;
+};
 
-static struct device_attribute power_supply_attrs[];
+#define POWER_SUPPLY_ATTR(_name)       \
+[POWER_SUPPLY_PROP_ ## _name] =                \
+{                                      \
+       .prop_name = #_name,            \
+       .attr_name = #_name "\0",       \
+}
 
 static const char * const power_supply_type_text[] = {
        "Unknown", "Battery", "UPS", "Mains", "USB",
@@ -77,6 +71,91 @@ static const char * const power_supply_scope_text[] = {
        "Unknown", "System", "Device"
 };
 
+static struct power_supply_attr 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(CHARGE_CONTROL_START_THRESHOLD),
+       POWER_SUPPLY_ATTR(CHARGE_CONTROL_END_THRESHOLD),
+       POWER_SUPPLY_ATTR(INPUT_CURRENT_LIMIT),
+       POWER_SUPPLY_ATTR(INPUT_VOLTAGE_LIMIT),
+       POWER_SUPPLY_ATTR(INPUT_POWER_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(USB_TYPE),
+       POWER_SUPPLY_ATTR(SCOPE),
+       POWER_SUPPLY_ATTR(PRECHARGE_CURRENT),
+       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 enum power_supply_property dev_attr_psp(struct device_attribute *attr)
+{
+       return container_of(attr, struct power_supply_attr, dev_attr) -
+               power_supply_attrs;
+}
+
 static ssize_t power_supply_show_usb_type(struct device *dev,
                                          enum power_supply_usb_type *usb_types,
                                          ssize_t num_usb_types,
@@ -117,7 +196,7 @@ static ssize_t power_supply_show_property(struct device 
*dev,
                                          char *buf) {
        ssize_t ret;
        struct power_supply *psy = dev_get_drvdata(dev);
-       enum power_supply_property psp = attr - power_supply_attrs;
+       enum power_supply_property psp = dev_attr_psp(attr);
        union power_supply_propval value;
 
        if (psp == POWER_SUPPLY_PROP_TYPE) {
@@ -186,7 +265,7 @@ static ssize_t power_supply_store_property(struct device 
*dev,
                                           const char *buf, size_t count) {
        ssize_t ret;
        struct power_supply *psy = dev_get_drvdata(dev);
-       enum power_supply_property psp = attr - power_supply_attrs;
+       enum power_supply_property psp = dev_attr_psp(attr);
        union power_supply_propval value;
 
        switch (psp) {
@@ -235,86 +314,6 @@ static ssize_t power_supply_store_property(struct device 
*dev,
        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(charge_control_start_threshold),
-       POWER_SUPPLY_ATTR(charge_control_end_threshold),
-       POWER_SUPPLY_ATTR(input_current_limit),
-       POWER_SUPPLY_ATTR(input_voltage_limit),
-       POWER_SUPPLY_ATTR(input_power_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(usb_type),
-       POWER_SUPPLY_ATTR(scope),
-       POWER_SUPPLY_ATTR(precharge_current),
-       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)
@@ -324,6 +323,9 @@ static umode_t power_supply_attr_is_visible(struct kobject 
*kobj,
        umode_t mode = S_IRUSR | S_IRGRP | S_IROTH;
        int i;
 
+       if (!power_supply_attrs[attrno].prop_name)
+               return 0;
+
        if (attrno == POWER_SUPPLY_PROP_TYPE)
                return mode;
 
@@ -352,31 +354,38 @@ static const struct attribute_group 
*power_supply_attr_groups[] = {
        NULL,
 };
 
-void power_supply_init_attrs(struct device_type *dev_type)
+static void str_to_lower(char *str)
 {
-       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;
+       while (*str) {
+               *str = tolower(*str);
+               str++;
+       }
 }
 
-static char *kstruprdup(const char *str, gfp_t gfp)
+void power_supply_init_attrs(struct device_type *dev_type)
 {
-       char *ret, *ustr;
+       int i;
 
-       ustr = ret = kmalloc(strlen(str) + 1, gfp);
+       dev_type->groups = power_supply_attr_groups;
 
-       if (!ret)
-               return NULL;
+       for (i = 0; i < ARRAY_SIZE(power_supply_attrs); i++) {
+               struct device_attribute *attr;
 
-       while (*str)
-               *ustr++ = toupper(*str++);
+               if (!power_supply_attrs[i].prop_name) {
+                       pr_warn("%s: Property %d skipped because is is missing 
from power_supply_attrs\n",
+                               __func__, i);
+                       sprintf(power_supply_attrs[i].attr_name, "_err_%d", i);
+               } else {
+                       str_to_lower(power_supply_attrs[i].attr_name);
+               }
 
-       *ustr = 0;
+               attr = &power_supply_attrs[i].dev_attr;
 
-       return ret;
+               attr->attr.name = power_supply_attrs[i].attr_name;
+               attr->show = power_supply_show_property;
+               attr->store = power_supply_store_property;
+               __power_supply_attrs[i] = &attr->attr;
+       }
 }
 
 int power_supply_uevent(struct device *dev, struct kobj_uevent_env *env)
@@ -384,7 +393,6 @@ 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;
 
        if (!psy || !psy->desc) {
                dev_dbg(dev, "No power supply yet\n");
@@ -400,12 +408,14 @@ int power_supply_uevent(struct device *dev, struct 
kobj_uevent_env *env)
                return -ENOMEM;
 
        for (j = 0; j < psy->desc->num_properties; j++) {
-               struct device_attribute *attr;
+               struct power_supply_attr *pwr_attr;
+               struct device_attribute *dev_attr;
                char *line;
 
-               attr = &power_supply_attrs[psy->desc->properties[j]];
+               pwr_attr = &power_supply_attrs[psy->desc->properties[j]];
+               dev_attr = &pwr_attr->dev_attr;
 
-               ret = power_supply_show_property(dev, attr, prop_buf);
+               ret = power_supply_show_property(dev, 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 */
@@ -420,14 +430,8 @@ int power_supply_uevent(struct device *dev, struct 
kobj_uevent_env *env)
                if (line)
                        *line = 0;
 
-               attrname = kstruprdup(attr->attr.name, GFP_KERNEL);
-               if (!attrname) {
-                       ret = -ENOMEM;
-                       goto out;
-               }
-
-               ret = add_uevent_var(env, "POWER_SUPPLY_%s=%s", attrname, 
prop_buf);
-               kfree(attrname);
+               ret = add_uevent_var(env, "POWER_SUPPLY_%s=%s",
+                                    pwr_attr->prop_name, prop_buf);
                if (ret)
                        goto out;
        }
-- 
2.26.2.526.g744177e7f7-goog

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