Commit 744c2fe9 authored by Arnd Bergmann's avatar Arnd Bergmann Committed by Guenter Roeck
Browse files

hwmon: (occ) Rework attribute registration for stack usage 

clang produces an output with excessive stack usage when building the
occ_setup_sensor_attrs() function, apparently the result of having
a lot of struct literals and building with the -fno-strict-overflow
option that leads clang to skip some optimization in case the 'attr'
pointer overruns:

drivers/hwmon/occ/common.c:775:12: error: stack frame size (1392) exceeds limit (1280) in 'occ_setup_sensor_attrs' [-Werror,-Wframe-larger-than]

Replace the custom macros for initializing the attributes with a
simpler function call that does not run into this corner case.

Link: https://godbolt.org/z/Wf1Yx76a5


Fixes: 54076cb3 ("hwmon (occ): Add sensor attributes and register hwmon device")
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20250610092315.2640039-1-arnd@kernel.org


Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent 14c9ede9

drivers/hwmon/occ/common.c

+85 −127
Original line number Diff line number Diff line
@@ -747,28 +747,29 @@ static ssize_t occ_show_extended(struct device *dev, 
}



/*

 * Some helper macros to make it easier to define an occ_attribute. Since these

 * are dynamically allocated, we shouldn't use the existing kernel macros which

 * A helper to make it easier to define an occ_attribute. Since these

 * are dynamically allocated, we cannot use the existing kernel macros which

 * stringify the name argument.

 */

#define ATTR_OCC(_name, _mode, _show, _store) {				\

	.attr	= {							\

		.name = _name,						\

		.mode = VERIFY_OCTAL_PERMISSIONS(_mode),		\

	},								\

	.show	= _show,						\

	.store	= _store,						\

}

static void occ_init_attribute(struct occ_attribute *attr, int mode,

	ssize_t (*show)(struct device *dev, struct device_attribute *attr, char *buf),

	ssize_t (*store)(struct device *dev, struct device_attribute *attr,

				   const char *buf, size_t count),

	int nr, int index, const char *fmt, ...)

{

	va_list args;



#define SENSOR_ATTR_OCC(_name, _mode, _show, _store, _nr, _index) {	\

	.dev_attr	= ATTR_OCC(_name, _mode, _show, _store),	\

	.index		= _index,					\

	.nr		= _nr,						\

}

	va_start(args, fmt);

	vsnprintf(attr->name, sizeof(attr->name), fmt, args);

	va_end(args);



#define OCC_INIT_ATTR(_name, _mode, _show, _store, _nr, _index)		\

	((struct sensor_device_attribute_2)				\

		SENSOR_ATTR_OCC(_name, _mode, _show, _store, _nr, _index))

	attr->sensor.dev_attr.attr.name = attr->name;

	attr->sensor.dev_attr.attr.mode = mode;

	attr->sensor.dev_attr.show = show;

	attr->sensor.dev_attr.store = store;

	attr->sensor.index = index;

	attr->sensor.nr = nr;

}



/*

 * Allocate and instatiate sensor_device_attribute_2s. It's most efficient to
@@ -855,14 +856,15 @@ static int occ_setup_sensor_attrs(struct occ *occ) 
		sensors->extended.num_sensors = 0;

	}



	occ->attrs = devm_kzalloc(dev, sizeof(*occ->attrs) * num_attrs,

	occ->attrs = devm_kcalloc(dev, num_attrs, sizeof(*occ->attrs),

				  GFP_KERNEL);

	if (!occ->attrs)

		return -ENOMEM;



	/* null-terminated list */

	occ->group.attrs = devm_kzalloc(dev, sizeof(*occ->group.attrs) *

					num_attrs + 1, GFP_KERNEL);

	occ->group.attrs = devm_kcalloc(dev, num_attrs + 1,

					sizeof(*occ->group.attrs),

					GFP_KERNEL);

	if (!occ->group.attrs)

		return -ENOMEM;
@@ -872,43 +874,33 @@ static int occ_setup_sensor_attrs(struct occ *occ) 
		s = i + 1;

		temp = ((struct temp_sensor_2 *)sensors->temp.data) + i;



		snprintf(attr->name, sizeof(attr->name), "temp%d_label", s);

		attr->sensor = OCC_INIT_ATTR(attr->name, 0444, show_temp, NULL,

					     0, i);

		occ_init_attribute(attr, 0444, show_temp, NULL,

				   0, i, "temp%d_label", s);

		attr++;



		if (sensors->temp.version == 2 &&

		    temp->fru_type == OCC_FRU_TYPE_VRM) {

			snprintf(attr->name, sizeof(attr->name),

				 "temp%d_alarm", s);

			occ_init_attribute(attr, 0444, show_temp, NULL,

					   1, i, "temp%d_alarm", s);

		} else {

			snprintf(attr->name, sizeof(attr->name),

				 "temp%d_input", s);

			occ_init_attribute(attr, 0444, show_temp, NULL,

					   1, i, "temp%d_input", s);

		}



		attr->sensor = OCC_INIT_ATTR(attr->name, 0444, show_temp, NULL,

					     1, i);

		attr++;



		if (sensors->temp.version > 1) {

			snprintf(attr->name, sizeof(attr->name),

				 "temp%d_fru_type", s);

			attr->sensor = OCC_INIT_ATTR(attr->name, 0444,

						     show_temp, NULL, 2, i);

			occ_init_attribute(attr, 0444, show_temp, NULL,

					   2, i, "temp%d_fru_type", s);

			attr++;



			snprintf(attr->name, sizeof(attr->name),

				 "temp%d_fault", s);

			attr->sensor = OCC_INIT_ATTR(attr->name, 0444,

						     show_temp, NULL, 3, i);

			occ_init_attribute(attr, 0444, show_temp, NULL,

					   3, i, "temp%d_fault", s);

			attr++;



			if (sensors->temp.version == 0x10) {

				snprintf(attr->name, sizeof(attr->name),

					 "temp%d_max", s);

				attr->sensor = OCC_INIT_ATTR(attr->name, 0444,

							     show_temp, NULL,

							     4, i);

				occ_init_attribute(attr, 0444, show_temp, NULL,

						   4, i, "temp%d_max", s);

				attr++;

			}

		}
@@ -917,14 +909,12 @@ static int occ_setup_sensor_attrs(struct occ *occ) 
	for (i = 0; i < sensors->freq.num_sensors; ++i) {

		s = i + 1;



		snprintf(attr->name, sizeof(attr->name), "freq%d_label", s);

		attr->sensor = OCC_INIT_ATTR(attr->name, 0444, show_freq, NULL,

					     0, i);

		occ_init_attribute(attr, 0444, show_freq, NULL,

				   0, i, "freq%d_label", s);

		attr++;



		snprintf(attr->name, sizeof(attr->name), "freq%d_input", s);

		attr->sensor = OCC_INIT_ATTR(attr->name, 0444, show_freq, NULL,

					     1, i);

		occ_init_attribute(attr, 0444, show_freq, NULL,

				   1, i, "freq%d_input", s);

		attr++;

	}
@@ -940,32 +930,24 @@ static int occ_setup_sensor_attrs(struct occ *occ) 
			s = (i * 4) + 1;



			for (j = 0; j < 4; ++j) {

				snprintf(attr->name, sizeof(attr->name),

				occ_init_attribute(attr, 0444, show_power,

						   NULL, nr++, i,

						   "power%d_label", s);

				attr->sensor = OCC_INIT_ATTR(attr->name, 0444,

							     show_power, NULL,

							     nr++, i);

				attr++;



				snprintf(attr->name, sizeof(attr->name),

				occ_init_attribute(attr, 0444, show_power,

						   NULL, nr++, i,

						   "power%d_average", s);

				attr->sensor = OCC_INIT_ATTR(attr->name, 0444,

							     show_power, NULL,

							     nr++, i);

				attr++;



				snprintf(attr->name, sizeof(attr->name),

				occ_init_attribute(attr, 0444, show_power,

						   NULL, nr++, i,

						   "power%d_average_interval", s);

				attr->sensor = OCC_INIT_ATTR(attr->name, 0444,

							     show_power, NULL,

							     nr++, i);

				attr++;



				snprintf(attr->name, sizeof(attr->name),

				occ_init_attribute(attr, 0444, show_power,

						   NULL, nr++, i,

						   "power%d_input", s);

				attr->sensor = OCC_INIT_ATTR(attr->name, 0444,

							     show_power, NULL,

							     nr++, i);

				attr++;



				s++;
@@ -977,28 +959,20 @@ static int occ_setup_sensor_attrs(struct occ *occ) 
		for (i = 0; i < sensors->power.num_sensors; ++i) {

			s = i + 1;



			snprintf(attr->name, sizeof(attr->name),

				 "power%d_label", s);

			attr->sensor = OCC_INIT_ATTR(attr->name, 0444,

						     show_power, NULL, 0, i);

			occ_init_attribute(attr, 0444, show_power, NULL,

					   0, i, "power%d_label", s);

			attr++;



			snprintf(attr->name, sizeof(attr->name),

				 "power%d_average", s);

			attr->sensor = OCC_INIT_ATTR(attr->name, 0444,

						     show_power, NULL, 1, i);

			occ_init_attribute(attr, 0444, show_power, NULL,

					   1, i, "power%d_average", s);

			attr++;



			snprintf(attr->name, sizeof(attr->name),

				 "power%d_average_interval", s);

			attr->sensor = OCC_INIT_ATTR(attr->name, 0444,

						     show_power, NULL, 2, i);

			occ_init_attribute(attr, 0444, show_power, NULL,

					   2, i, "power%d_average_interval", s);

			attr++;



			snprintf(attr->name, sizeof(attr->name),

				 "power%d_input", s);

			attr->sensor = OCC_INIT_ATTR(attr->name, 0444,

						     show_power, NULL, 3, i);

			occ_init_attribute(attr, 0444, show_power, NULL,

					   3, i, "power%d_input", s);

			attr++;

		}
@@ -1006,56 +980,43 @@ static int occ_setup_sensor_attrs(struct occ *occ) 
	}



	if (sensors->caps.num_sensors >= 1) {

		snprintf(attr->name, sizeof(attr->name), "power%d_label", s);

		attr->sensor = OCC_INIT_ATTR(attr->name, 0444, show_caps, NULL,

					     0, 0);

		occ_init_attribute(attr, 0444, show_caps, NULL,

				   0, 0, "power%d_label", s);

		attr++;



		snprintf(attr->name, sizeof(attr->name), "power%d_cap", s);

		attr->sensor = OCC_INIT_ATTR(attr->name, 0444, show_caps, NULL,

					     1, 0);

		occ_init_attribute(attr, 0444, show_caps, NULL,

				   1, 0, "power%d_cap", s);

		attr++;



		snprintf(attr->name, sizeof(attr->name), "power%d_input", s);

		attr->sensor = OCC_INIT_ATTR(attr->name, 0444, show_caps, NULL,

					     2, 0);

		occ_init_attribute(attr, 0444, show_caps, NULL,

				   2, 0, "power%d_input", s);

		attr++;



		snprintf(attr->name, sizeof(attr->name),

			 "power%d_cap_not_redundant", s);

		attr->sensor = OCC_INIT_ATTR(attr->name, 0444, show_caps, NULL,

					     3, 0);

		occ_init_attribute(attr, 0444, show_caps, NULL,

				   3, 0, "power%d_cap_not_redundant", s);

		attr++;



		snprintf(attr->name, sizeof(attr->name), "power%d_cap_max", s);

		attr->sensor = OCC_INIT_ATTR(attr->name, 0444, show_caps, NULL,

					     4, 0);

		occ_init_attribute(attr, 0444, show_caps, NULL,

				   4, 0, "power%d_cap_max", s);

		attr++;



		snprintf(attr->name, sizeof(attr->name), "power%d_cap_min", s);

		attr->sensor = OCC_INIT_ATTR(attr->name, 0444, show_caps, NULL,

					     5, 0);

		occ_init_attribute(attr, 0444, show_caps, NULL,

				   5, 0, "power%d_cap_min", s);

		attr++;



		snprintf(attr->name, sizeof(attr->name), "power%d_cap_user",

			 s);

		attr->sensor = OCC_INIT_ATTR(attr->name, 0644, show_caps,

					     occ_store_caps_user, 6, 0);

		occ_init_attribute(attr, 0644, show_caps, occ_store_caps_user,

				   6, 0, "power%d_cap_user", s);

		attr++;



		if (sensors->caps.version > 1) {

			snprintf(attr->name, sizeof(attr->name),

				 "power%d_cap_user_source", s);

			attr->sensor = OCC_INIT_ATTR(attr->name, 0444,

						     show_caps, NULL, 7, 0);

			occ_init_attribute(attr, 0444, show_caps, NULL,

					   7, 0, "power%d_cap_user_source", s);

			attr++;



			if (sensors->caps.version > 2) {

				snprintf(attr->name, sizeof(attr->name),

				occ_init_attribute(attr, 0444, show_caps, NULL,

						   8, 0,

						   "power%d_cap_min_soft", s);

				attr->sensor = OCC_INIT_ATTR(attr->name, 0444,

							     show_caps, NULL,

							     8, 0);

				attr++;

			}

		}
@@ -1064,19 +1025,16 @@ static int occ_setup_sensor_attrs(struct occ *occ) 
	for (i = 0; i < sensors->extended.num_sensors; ++i) {

		s = i + 1;



		snprintf(attr->name, sizeof(attr->name), "extn%d_label", s);

		attr->sensor = OCC_INIT_ATTR(attr->name, 0444,

					     occ_show_extended, NULL, 0, i);

		occ_init_attribute(attr, 0444, occ_show_extended, NULL,

				   0, i, "extn%d_label", s);

		attr++;



		snprintf(attr->name, sizeof(attr->name), "extn%d_flags", s);

		attr->sensor = OCC_INIT_ATTR(attr->name, 0444,

					     occ_show_extended, NULL, 1, i);

		occ_init_attribute(attr, 0444, occ_show_extended, NULL,

				   1, i, "extn%d_flags", s);

		attr++;



		snprintf(attr->name, sizeof(attr->name), "extn%d_input", s);

		attr->sensor = OCC_INIT_ATTR(attr->name, 0444,

					     occ_show_extended, NULL, 2, i);

		occ_init_attribute(attr, 0444, occ_show_extended, NULL,

				   2, i, "extn%d_input", s);

		attr++;

	}