Commit 75bd50fa authored by Tian Tao's avatar Tian Tao Committed by Greg Kroah-Hartman
Browse files

drivers/base/node.c: use bin_attribute to break the size limitation of cpumap ABI 



Reading /sys/devices/system/cpu/cpuX/nodeX/ returns cpumap and cpulist.
However, the size of this file is limited to PAGE_SIZE because of the
limitation for sysfs attribute.

This patch moves to use bin_attribute to extend the ABI to be more
than one page so that cpumap bitmask and list won't be potentially
trimmed.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Reviewed-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: default avatarTian Tao <tiantao6@hisilicon.com>
Signed-off-by: default avatarBarry Song <song.bao.hua@hisilicon.com>
Link: https://lore.kernel.org/r/20210806110251.560-5-song.bao.hua@hisilicon.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent bb9ec13d

drivers/base/node.c

+40 −23
Original line number Diff line number Diff line
@@ -26,43 +26,47 @@ static struct bus_type node_subsys = { 
	.dev_name = "node",

};





static ssize_t node_read_cpumap(struct device *dev, bool list, char *buf)

static inline ssize_t cpumap_read(struct file *file, struct kobject *kobj,

				  struct bin_attribute *attr, char *buf,

				  loff_t off, size_t count)

{

	ssize_t n;

	cpumask_var_t mask;

	struct device *dev = kobj_to_dev(kobj);

	struct node *node_dev = to_node(dev);



	/* 2008/04/07: buf currently PAGE_SIZE, need 9 chars per 32 bits. */

	BUILD_BUG_ON((NR_CPUS/32 * 9) > (PAGE_SIZE-1));

	cpumask_var_t mask;

	ssize_t n;



	if (!alloc_cpumask_var(&mask, GFP_KERNEL))

		return 0;



	cpumask_and(mask, cpumask_of_node(node_dev->dev.id), cpu_online_mask);

	n = cpumap_print_to_pagebuf(list, buf, mask);

	n = cpumap_print_bitmask_to_buf(buf, mask, off, count);

	free_cpumask_var(mask);



	return n;

}



static inline ssize_t cpumap_show(struct device *dev,

				  struct device_attribute *attr,

				  char *buf)

static BIN_ATTR_RO(cpumap, 0);



static inline ssize_t cpulist_read(struct file *file, struct kobject *kobj,

				   struct bin_attribute *attr, char *buf,

				   loff_t off, size_t count)

{

	return node_read_cpumap(dev, false, buf);

}

	struct device *dev = kobj_to_dev(kobj);

	struct node *node_dev = to_node(dev);

	cpumask_var_t mask;

	ssize_t n;



	if (!alloc_cpumask_var(&mask, GFP_KERNEL))

		return 0;



static DEVICE_ATTR_RO(cpumap);

	cpumask_and(mask, cpumask_of_node(node_dev->dev.id), cpu_online_mask);

	n = cpumap_print_list_to_buf(buf, mask, off, count);

	free_cpumask_var(mask);



static inline ssize_t cpulist_show(struct device *dev,

				   struct device_attribute *attr,

				   char *buf)

{

	return node_read_cpumap(dev, true, buf);

	return n;

}



static DEVICE_ATTR_RO(cpulist);

static BIN_ATTR_RO(cpulist, 0);



/**

 * struct node_access_nodes - Access class device to hold user visible
@@ -557,15 +561,28 @@ static ssize_t node_read_distance(struct device *dev, 
static DEVICE_ATTR(distance, 0444, node_read_distance, NULL);



static struct attribute *node_dev_attrs[] = {

	&dev_attr_cpumap.attr,

	&dev_attr_cpulist.attr,

	&dev_attr_meminfo.attr,

	&dev_attr_numastat.attr,

	&dev_attr_distance.attr,

	&dev_attr_vmstat.attr,

	NULL

};

ATTRIBUTE_GROUPS(node_dev);



static struct bin_attribute *node_dev_bin_attrs[] = {

	&bin_attr_cpumap,

	&bin_attr_cpulist,

	NULL

};



static const struct attribute_group node_dev_group = {

	.attrs = node_dev_attrs,

	.bin_attrs = node_dev_bin_attrs

};



static const struct attribute_group *node_dev_groups[] = {

	&node_dev_group,

	NULL

};



#ifdef CONFIG_HUGETLBFS

/*