drivers core: Use sysfs_emit for shared_cpu_map_show and shared_cpu_list_show

mainline inclusion
from mainline-v5.10-rc1
commit e015e036
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I5C32F
CVE: CVE-2022-20166

--------------------------------------------------

Do not indirect the bitmap printing of these shared_cpu show functions by
using cpumap_print_to_pagebuf/bitmap_print_to_pagebuf.

Use the more typical style with the vsnprintf %*pb and %*pbl extensions
directly so there is no possible mixup about the use of offset_in_page(buf)
by bitmap_print_to_pagebuf.
Signed-off-by: NJoe Perches <joe@perches.com>
Link: https://lore.kernel.org/r/80457b467ab6cde13a173cfd8a4f49cd8467a7fd.1600285923.git.joe@perches.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: NWeilong Chen <chenweilong@huawei.com>
Reviewed-by: NXiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: NYongqiang Liu <liuyongqiang13@huawei.com>

drivers/base/cacheinfo.c

@@ -418,24 +418,22 @@ static ssize_t size_show(struct device *dev,
 	return sysfs_emit(buf, "%uK\n", this_leaf->size >> 10);
 }
 
-static ssize_t shared_cpumap_show_func(struct device *dev, bool list, char *buf)
+static ssize_t shared_cpu_map_show(struct device *dev,
+				   struct device_attribute *attr, char *buf)
 {
 	struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 	const struct cpumask *mask = &this_leaf->shared_cpu_map;
 
-	return cpumap_print_to_pagebuf(list, buf, mask);
-}
-
-static ssize_t shared_cpu_map_show(struct device *dev,
-				   struct device_attribute *attr, char *buf)
-{
-	return shared_cpumap_show_func(dev, false, buf);
+	return sysfs_emit(buf, "%*pb\n", nr_cpu_ids, mask);
 }
 
 static ssize_t shared_cpu_list_show(struct device *dev,
 				    struct device_attribute *attr, char *buf)
 {
-	return shared_cpumap_show_func(dev, true, buf);
+	struct cacheinfo *this_leaf = dev_get_drvdata(dev);
+	const struct cpumask *mask = &this_leaf->shared_cpu_map;
+
+	return sysfs_emit(buf, "%*pbl\n", nr_cpu_ids, mask);
 }
 
 static ssize_t type_show(struct device *dev,