drivers core: Miscellaneous changes for sysfs_emit

mainline inclusion
from mainline-v5.10-rc1
commit 948b3edb
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I5C32F
CVE: CVE-2022-20166

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

Change additional instances that could use sysfs_emit and sysfs_emit_at
that the coccinelle script could not convert.

o macros creating show functions with ## concatenation
o unbound sprintf uses with buf+len for start of output to sysfs_emit_at
o returns with ?: tests and sprintf to sysfs_emit
o sysfs output with struct class * not struct device * arguments

Miscellanea:

o remove unnecessary initializations around these changes
o consistently use int len for return length of show functions
o use octal permissions and not S_<FOO>
o rename a few show function names so DEVICE_ATTR_<FOO> can be used
o use DEVICE_ATTR_ADMIN_RO where appropriate
o consistently use const char *output for strings
o checkpatch/style neatening
Signed-off-by: NJoe Perches <joe@perches.com>
Link: https://lore.kernel.org/r/8bc24444fe2049a9b2de6127389b57edfdfe324d.1600285923.git.joe@perches.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Conflicts:
	drivers/base/bus.c
	drivers/base/core.c
	drivers/base/cpu.c
	drivers/base/dd.c
	drivers/base/memory.c
	drivers/base/node.c
    drivers/base/platform.c
    drivers/base/power/sysfs.c
    drivers/base/soc.c
Signed-off-by: NGuo Mengqi <guomengqi3@huawei.com>
Reviewed-by: NWeilong Chen <chenweilong@huawei.com>
Reviewed-by: NXiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: NYongqiang Liu <liuyongqiang13@huawei.com>

drivers/base/bus.c

@@ -228,7 +228,7 @@ static DRIVER_ATTR_IGNORE_LOCKDEP(bind, S_IWUSR, NULL, bind_store);
 
 static ssize_t show_drivers_autoprobe(struct bus_type *bus, char *buf)
 {
-	return sprintf(buf, "%d\n", bus->p->drivers_autoprobe);
+	return sysfs_emit(buf, "%d\n", bus->p->drivers_autoprobe);
 }
 
 static ssize_t store_drivers_autoprobe(struct bus_type *bus,

drivers/base/cacheinfo.c

@@ -400,7 +400,7 @@ static ssize_t file_name##_show(struct device *dev,		\
 		struct device_attribute *attr, char *buf)	\
 {								\
 	struct cacheinfo *this_leaf = dev_get_drvdata(dev);	\
-	return sprintf(buf, "%u\n", this_leaf->object);		\
+	return sysfs_emit(buf, "%u\n", this_leaf->object);	\
 }
 
 show_one(id, id);

drivers/base/class.c

@@ -471,7 +471,7 @@ ssize_t show_class_attr_string(struct class *class,
 	struct class_attribute_string *cs;
 
 	cs = container_of(attr, struct class_attribute_string, attr);
-	return snprintf(buf, PAGE_SIZE, "%s\n", cs->str);
+	return sysfs_emit(buf, "%s\n", cs->str);
 }
 
 EXPORT_SYMBOL_GPL(show_class_attr_string);

drivers/base/core.c

@@ -1213,7 +1213,7 @@ static ssize_t uevent_show(struct device *dev, struct device_attribute *attr,
 	struct kset *kset;
 	struct kobj_uevent_env *env = NULL;
 	int i;
-	size_t count = 0;
+	int len = 0;
 	int retval;
 
 	/* search the kset, the device belongs to */
@@ -1243,10 +1243,10 @@ static ssize_t uevent_show(struct device *dev, struct device_attribute *attr,
 
 	/* copy keys to file */
 	for (i = 0; i < env->envp_idx; i++)
-		count += sprintf(&buf[count], "%s\n", env->envp[i]);
+		len += sysfs_emit_at(buf, len, "%s\n", env->envp[i]);
 out:
 	kfree(env);
-	return count;
+	return len;
 }
 
 static ssize_t uevent_store(struct device *dev, struct device_attribute *attr,

drivers/base/cpu.c

@@ -139,11 +139,11 @@ EXPORT_SYMBOL_GPL(cpu_subsys);
 #ifdef CONFIG_KEXEC
 #include <linux/kexec.h>
 
-static ssize_t show_crash_notes(struct device *dev, struct device_attribute *attr,
+static ssize_t crash_notes_show(struct device *dev,
+				struct device_attribute *attr,
 				char *buf)
 {
 	struct cpu *cpu = container_of(dev, struct cpu, dev);
-	ssize_t rc;
 	unsigned long long addr;
 	int cpunum;
 
@@ -156,21 +156,18 @@ static ssize_t show_crash_notes(struct device *dev, struct device_attribute *att
 	 * operation should be safe. No locking required.
 	 */
 	addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpunum));
-	rc = sysfs_emit(buf, "%Lx\n", addr);
-	return rc;
+
+	return sysfs_emit(buf, "%llx\n", addr);
 }
-static DEVICE_ATTR(crash_notes, 0400, show_crash_notes, NULL);
+static DEVICE_ATTR(crash_notes, 0400, crash_notes_show, NULL);
 
-static ssize_t show_crash_notes_size(struct device *dev,
+static ssize_t crash_notes_size_show(struct device *dev,
 				     struct device_attribute *attr,
 				     char *buf)
 {
-	ssize_t rc;
-
-	rc = sysfs_emit(buf, "%zu\n", sizeof(note_buf_t));
-	return rc;
+	return sysfs_emit(buf, "%zu\n", sizeof(note_buf_t));
 }
-static DEVICE_ATTR(crash_notes_size, 0400, show_crash_notes_size, NULL);
+static DEVICE_ATTR(crash_notes_size, 0400, crash_notes_size_show, NULL);
 
 static struct attribute *crash_note_cpu_attrs[] = {
 	&dev_attr_crash_notes.attr,
@@ -231,8 +228,7 @@ static struct cpu_attr cpu_attrs[] = {
 static ssize_t print_cpus_kernel_max(struct device *dev,
 				     struct device_attribute *attr, char *buf)
 {
-	int n = snprintf(buf, PAGE_SIZE-2, "%d\n", NR_CPUS - 1);
-	return n;
+	return sysfs_emit(buf, "%d\n", NR_CPUS - 1);
 }
 static DEVICE_ATTR(kernel_max, 0444, print_cpus_kernel_max, NULL);
 
@@ -242,37 +238,37 @@ unsigned int total_cpus;
 static ssize_t print_cpus_offline(struct device *dev,
 				  struct device_attribute *attr, char *buf)
 {
-	int n = 0, len = PAGE_SIZE-2;
+	int len = 0;
 	cpumask_var_t offline;
 
 	/* display offline cpus < nr_cpu_ids */
 	if (!alloc_cpumask_var(&offline, GFP_KERNEL))
 		return -ENOMEM;
 	cpumask_andnot(offline, cpu_possible_mask, cpu_online_mask);
-	n = scnprintf(buf, len, "%*pbl", cpumask_pr_args(offline));
+	len += sysfs_emit_at(buf, len, "%*pbl", cpumask_pr_args(offline));
 	free_cpumask_var(offline);
 
 	/* display offline cpus >= nr_cpu_ids */
 	if (total_cpus && nr_cpu_ids < total_cpus) {
-		if (n && n < len)
-			buf[n++] = ',';
+		len += sysfs_emit_at(buf, len, ",");
 
 		if (nr_cpu_ids == total_cpus-1)
-			n += snprintf(&buf[n], len - n, "%u", nr_cpu_ids);
+			len += sysfs_emit_at(buf, len, "%u", nr_cpu_ids);
 		else
-			n += snprintf(&buf[n], len - n, "%u-%d",
-						      nr_cpu_ids, total_cpus-1);
+			len += sysfs_emit_at(buf, len, "%u-%d",
+					nr_cpu_ids, total_cpus - 1);
 	}
 
-	n += snprintf(&buf[n], len - n, "\n");
-	return n;
+	len += sysfs_emit_at(buf, len, "\n");
+
+	return len;
 }
 static DEVICE_ATTR(offline, 0444, print_cpus_offline, NULL);
 
 static ssize_t print_cpus_isolated(struct device *dev,
 				  struct device_attribute *attr, char *buf)
 {
-	int n = 0, len = PAGE_SIZE-2;
+	int len;
 	cpumask_var_t isolated;
 
 	if (!alloc_cpumask_var(&isolated, GFP_KERNEL))
@@ -280,11 +276,11 @@ static ssize_t print_cpus_isolated(struct device *dev,
 
 	cpumask_andnot(isolated, cpu_possible_mask,
 		       housekeeping_cpumask(HK_FLAG_DOMAIN));
-	n = scnprintf(buf, len, "%*pbl\n", cpumask_pr_args(isolated));
+	len = sysfs_emit(buf, "%*pbl\n", cpumask_pr_args(isolated));
 
 	free_cpumask_var(isolated);
 
-	return n;
+	return len;
 }
 static DEVICE_ATTR(isolated, 0444, print_cpus_isolated, NULL);
 
@@ -292,11 +288,7 @@ static DEVICE_ATTR(isolated, 0444, print_cpus_isolated, NULL);
 static ssize_t print_cpus_nohz_full(struct device *dev,
 				  struct device_attribute *attr, char *buf)
 {
-	int n = 0, len = PAGE_SIZE-2;
-
-	n = scnprintf(buf, len, "%*pbl\n", cpumask_pr_args(tick_nohz_full_mask));
-
-	return n;
+	return sysfs_emit(buf, "%*pbl\n", cpumask_pr_args(tick_nohz_full_mask));
 }
 static DEVICE_ATTR(nohz_full, 0444, print_cpus_nohz_full, NULL);
 #endif
@@ -325,22 +317,23 @@ static ssize_t print_cpu_modalias(struct device *dev,
 				  struct device_attribute *attr,
 				  char *buf)
 {
-	ssize_t n;
+	int len = 0;
 	u32 i;
 
-	n = sysfs_emit(buf, "cpu:type:" CPU_FEATURE_TYPEFMT ":feature:",
-		       CPU_FEATURE_TYPEVAL);
+	len += sysfs_emit_at(buf, len,
+			     "cpu:type:" CPU_FEATURE_TYPEFMT ":feature:",
+			     CPU_FEATURE_TYPEVAL);
 
 	for (i = 0; i < MAX_CPU_FEATURES; i++)
 		if (cpu_have_feature(i)) {
-			if (PAGE_SIZE < n + sizeof(",XXXX\n")) {
+			if (len + sizeof(",XXXX\n") >= PAGE_SIZE) {
 				WARN(1, "CPU features overflow page\n");
 				break;
 			}
-			n += sprintf(&buf[n], ",%04X", i);
+			len += sysfs_emit_at(buf, len, ",%04X", i);
 		}
-	buf[n++] = '\n';
-	return n;
+	len += sysfs_emit_at(buf, len, "\n");
+	return len;
 }
 
 static int cpu_uevent(struct device *dev, struct kobj_uevent_env *env)
@@ -560,7 +553,7 @@ ssize_t __weak cpu_show_tsx_async_abort(struct device *dev,
 }
 
 ssize_t __weak cpu_show_itlb_multihit(struct device *dev,
-			    struct device_attribute *attr, char *buf)
+				      struct device_attribute *attr, char *buf)
 {
 	return sysfs_emit(buf, "Not affected\n");
 }

drivers/base/devcoredump.c

@@ -123,7 +123,7 @@ static int devcd_free(struct device *dev, void *data)
 static ssize_t disabled_show(struct class *class, struct class_attribute *attr,
 			     char *buf)
 {
-	return sprintf(buf, "%d\n", devcd_disabled);
+	return sysfs_emit(buf, "%d\n", devcd_disabled);
 }
 
 static ssize_t disabled_store(struct class *class, struct class_attribute *attr,

drivers/base/firmware_loader/fallback.c

@@ -121,7 +121,7 @@ void kill_pending_fw_fallback_reqs(bool only_kill_custom)
 static ssize_t timeout_show(struct class *class, struct class_attribute *attr,
 			    char *buf)
 {
-	return sprintf(buf, "%d\n", __firmware_loading_timeout());
+	return sysfs_emit(buf, "%d\n", __firmware_loading_timeout());
 }
 
 /**

drivers/base/memory.c

@@ -140,6 +140,7 @@ static ssize_t phys_index_show(struct device *dev,
 	unsigned long phys_index;
 
 	phys_index = mem->start_section_nr / sections_per_block;
+
 	return sysfs_emit(buf, "%08lx\n", phys_index);
 }
 
@@ -387,6 +388,7 @@ static ssize_t phys_device_show(struct device *dev,
 				struct device_attribute *attr, char *buf)
 {
 	struct memory_block *mem = to_memory_block(dev);
+
 	return sysfs_emit(buf, "%d\n", mem->phys_device);
 }
 
@@ -400,6 +402,7 @@ static int print_allowed_zone(char *buf, int len, int nid,
 	zone = zone_for_pfn_range(online_type, nid, start_pfn, nr_pages);
 	if (zone == default_zone)
 		return 0;
+
 	return sysfs_emit_at(buf, len, " %s", zone->name);
 }
 
@@ -441,7 +444,7 @@ static ssize_t valid_zones_show(struct device *dev,
 	len += print_allowed_zone(buf, len, nid, start_pfn, nr_pages,
 			MMOP_ONLINE_MOVABLE, default_zone);
 out:
-	len += sysfs_emit_at(buf, len, "%s", "\n");
+	len += sysfs_emit_at(buf, len, "\n");
 	return len;
 }
 static DEVICE_ATTR_RO(valid_zones);

drivers/base/node.c

@@ -46,19 +46,23 @@ static ssize_t node_read_cpumap(struct device *dev, bool list, char *buf)
 	return n;
 }
 
-static inline ssize_t node_read_cpumask(struct device *dev,
-				struct device_attribute *attr, char *buf)
+static inline ssize_t cpumap_show(struct device *dev,
+				  struct device_attribute *attr,
+				  char *buf)
 {
 	return node_read_cpumap(dev, false, buf);
 }
-static inline ssize_t node_read_cpulist(struct device *dev,
-				struct device_attribute *attr, char *buf)
+
+static DEVICE_ATTR_RO(cpumap);
+
+static inline ssize_t cpulist_show(struct device *dev,
+				   struct device_attribute *attr,
+				   char *buf)
 {
 	return node_read_cpumap(dev, true, buf);
 }
 
-static DEVICE_ATTR(cpumap,  S_IRUGO, node_read_cpumask, NULL);
-static DEVICE_ATTR(cpulist, S_IRUGO, node_read_cpulist, NULL);
+static DEVICE_ATTR_RO(cpulist);
 
 /**
  * struct node_access_nodes - Access class device to hold user visible
@@ -152,13 +156,14 @@ static struct node_access_nodes *node_init_node_access(struct node *node,
 }
 
 #ifdef CONFIG_HMEM_REPORTING
-#define ACCESS_ATTR(name) 						   \
-static ssize_t name##_show(struct device *dev,				   \
-			   struct device_attribute *attr,		   \
-			   char *buf)					   \
-{									   \
-	return sprintf(buf, "%u\n", to_access_nodes(dev)->hmem_attrs.name); \
-}									   \
+#define ACCESS_ATTR(name)						\
+static ssize_t name##_show(struct device *dev,				\
+			   struct device_attribute *attr,		\
+			   char *buf)					\
+{									\
+	return sysfs_emit(buf, "%u\n",					\
+			  to_access_nodes(dev)->hmem_attrs.name);	\
+}									\
 static DEVICE_ATTR_RO(name);
 
 ACCESS_ATTR(read_bandwidth)
@@ -224,7 +229,8 @@ static ssize_t name##_show(struct device *dev,				\
 			   struct device_attribute *attr,		\
 			   char *buf)					\
 {									\
-	return sprintf(buf, fmt "\n", to_cache_info(dev)->cache_attrs.name);\
+	return sysfs_emit(buf, fmt "\n",				\
+			  to_cache_info(dev)->cache_attrs.name);	\
 }									\
 DEVICE_ATTR_RO(name);
 
@@ -358,13 +364,13 @@ static void node_remove_caches(struct node *node) { }
 static ssize_t node_read_meminfo(struct device *dev,
 			struct device_attribute *attr, char *buf)
 {
-	int n;
+	int len = 0;
 	int nid = dev->id;
 	struct pglist_data *pgdat = NODE_DATA(nid);
 	struct sysinfo i;
 
 	si_meminfo_node(&i, nid);
-	n = sprintf(buf,
+	len = sysfs_emit_at(buf, len,
 		       "Node %d MemTotal:       %8lu kB\n"
 		       "Node %d MemFree:        %8lu kB\n"
 		       "Node %d MemUsed:        %8lu kB\n"
@@ -391,7 +397,7 @@ static ssize_t node_read_meminfo(struct device *dev,
 		       nid, K(sum_zone_node_page_state(nid, NR_MLOCK)));
 
 #ifdef CONFIG_HIGHMEM
-	n += sprintf(buf + n,
+	len += sysfs_emit_at(buf, len,
 		       "Node %d HighTotal:      %8lu kB\n"
 		       "Node %d HighFree:       %8lu kB\n"
 		       "Node %d LowTotal:       %8lu kB\n"
@@ -401,7 +407,7 @@ static ssize_t node_read_meminfo(struct device *dev,
 		       nid, K(i.totalram - i.totalhigh),
 		       nid, K(i.freeram - i.freehigh));
 #endif
-	n += sprintf(buf + n,
+	len += sysfs_emit_at(buf, len,
 		       "Node %d Dirty:          %8lu kB\n"
 		       "Node %d Writeback:      %8lu kB\n"
 		       "Node %d FilePages:      %8lu kB\n"
@@ -447,8 +453,8 @@ static ssize_t node_read_meminfo(struct device *dev,
 #else
 		       nid, K(node_page_state(pgdat, NR_SLAB_UNRECLAIMABLE)));
 #endif
-	n += hugetlb_report_node_meminfo(nid, buf + n);
-	return n;
+	len += hugetlb_report_node_meminfo(nid, buf + len);
+	return len;
 }
 
 #undef K
@@ -471,7 +477,7 @@ static ssize_t node_read_numastat(struct device *dev,
 			  sum_zone_numa_state(dev->id, NUMA_LOCAL),
 			  sum_zone_numa_state(dev->id, NUMA_OTHER));
 }
-static DEVICE_ATTR(numastat, S_IRUGO, node_read_numastat, NULL);
+static DEVICE_ATTR(numastat, 0444, node_read_numastat, NULL);
 
 static ssize_t node_read_vmstat(struct device *dev,
 				struct device_attribute *attr, char *buf)
@@ -479,15 +485,16 @@ static ssize_t node_read_vmstat(struct device *dev,
 	int nid = dev->id;
 	struct pglist_data *pgdat = NODE_DATA(nid);
 	int i;
-	int n = 0;
+	int len = 0;
 
 	for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
-		n += sprintf(buf+n, "%s %lu\n", vmstat_text[i],
-			     sum_zone_node_page_state(nid, i));
+		len += sysfs_emit_at(buf, len, "%s %lu\n",
+				vmstat_text[i],
+				sum_zone_node_page_state(nid, i));
 
 #ifdef CONFIG_NUMA
 	for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++)
-		n += sprintf(buf+n, "%s %lu\n",
+		len += sysfs_emit_at(buf, len, "%s %lu\n",
 			     vmstat_text[i + NR_VM_ZONE_STAT_ITEMS],
 			     sum_zone_numa_state(nid, i));
 #endif
@@ -497,13 +504,13 @@ static ssize_t node_read_vmstat(struct device *dev,
 		if (*vmstat_text[i + NR_VM_ZONE_STAT_ITEMS +
 				 NR_VM_NUMA_STAT_ITEMS] == '\0')
 			continue;
-		n += sprintf(buf+n, "%s %lu\n",
+		len += sysfs_emit_at(buf, len, "%s %lu\n",
 			     vmstat_text[i + NR_VM_ZONE_STAT_ITEMS +
 			     NR_VM_NUMA_STAT_ITEMS],
 			     node_page_state(pgdat, i));
 	}
 
-	return n;
+	return len;
 }
 static DEVICE_ATTR(vmstat, S_IRUGO, node_read_vmstat, NULL);
 
@@ -520,13 +527,15 @@ static ssize_t node_read_distance(struct device *dev,
 	 */
 	BUILD_BUG_ON(MAX_NUMNODES * 4 > PAGE_SIZE);
 
-	for_each_online_node(i)
-		len += sprintf(buf + len, "%s%d", i ? " " : "", node_distance(nid, i));
+	for_each_online_node(i) {
+		len += sysfs_emit_at(buf, len, "%s%d",
+				     i ? " " : "", node_distance(nid, i));
+	}
 
-	len += sprintf(buf + len, "\n");
+	len += sysfs_emit_at(buf, len, "\n");
 	return len;
 }
-static DEVICE_ATTR(distance, S_IRUGO, node_read_distance, NULL);
+static DEVICE_ATTR(distance, 0444, node_read_distance, NULL);
 
 static struct attribute *node_dev_attrs[] = {
 	&dev_attr_cpumap.attr,
@@ -955,17 +964,6 @@ void unregister_one_node(int nid)
  * node states attributes
  */
 
-static ssize_t print_nodes_state(enum node_states state, char *buf)
-{
-	int n;
-
-	n = scnprintf(buf, PAGE_SIZE - 1, "%*pbl",
-		      nodemask_pr_args(&node_states[state]));
-	buf[n++] = '\n';
-	buf[n] = '\0';
-	return n;
-}
-
 struct node_attr {
 	struct device_attribute attr;
 	enum node_states state;
@@ -975,7 +973,9 @@ static ssize_t show_node_state(struct device *dev,
 			       struct device_attribute *attr, char *buf)
 {
 	struct node_attr *na = container_of(attr, struct node_attr, attr);
-	return print_nodes_state(na->state, buf);
+
+	return sysfs_emit(buf, "%*pbl\n",
+			  nodemask_pr_args(&node_states[na->state]));
 }
 
 #define _NODE_ATTR(name, state) \

drivers/base/platform.c

@@ -846,10 +846,10 @@ EXPORT_SYMBOL_GPL(platform_unregister_drivers);
  * (b) sysfs attribute lets new-style coldplug recover from hotplug events
  *     mishandled before system is fully running:  "modprobe $(cat modalias)"
  */
-static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
-			     char *buf)
+static ssize_t modalias_show(struct device *dev,
+			     struct device_attribute *attr, char *buf)
 {
-	struct platform_device	*pdev = to_platform_device(dev);
+	struct platform_device *pdev = to_platform_device(dev);
 	int len;
 
 	len = of_device_modalias(dev, buf, PAGE_SIZE);
@@ -860,9 +860,7 @@ static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
 	if (len != -ENODEV)
 		return len;
 
-	len = snprintf(buf, PAGE_SIZE, "platform:%s\n", pdev->name);
-
-	return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
+	return sysfs_emit(buf, "platform:%s\n", pdev->name);
 }
 static DEVICE_ATTR_RO(modalias);
 

drivers/base/power/sysfs.c

@@ -349,7 +349,7 @@ static DEVICE_ATTR_RW(wakeup);
 static ssize_t wakeup_count_show(struct device *dev,
 				 struct device_attribute *attr, char *buf)
 {
-	unsigned long count = 0;
+	unsigned long count;
 	bool enabled = false;
 
 	spin_lock_irq(&dev->power.lock);
@@ -358,7 +358,10 @@ static ssize_t wakeup_count_show(struct device *dev,
 		enabled = true;
 	}
 	spin_unlock_irq(&dev->power.lock);
-	return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
+
+	if (!enabled)
+		return sysfs_emit(buf, "\n");
+	return sysfs_emit(buf, "%lu\n", count);
 }
 
 static DEVICE_ATTR_RO(wakeup_count);
@@ -367,7 +370,7 @@ static ssize_t wakeup_active_count_show(struct device *dev,
 					struct device_attribute *attr,
 					char *buf)
 {
-	unsigned long count = 0;
+	unsigned long count;
 	bool enabled = false;
 
 	spin_lock_irq(&dev->power.lock);
@@ -376,7 +379,10 @@ static ssize_t wakeup_active_count_show(struct device *dev,
 		enabled = true;
 	}
 	spin_unlock_irq(&dev->power.lock);
-	return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
+
+	if (!enabled)
+		return sysfs_emit(buf, "\n");
+	return sysfs_emit(buf, "%lu\n", count);
 }
 
 static DEVICE_ATTR_RO(wakeup_active_count);
@@ -385,7 +391,7 @@ static ssize_t wakeup_abort_count_show(struct device *dev,
 				       struct device_attribute *attr,
 				       char *buf)
 {
-	unsigned long count = 0;
+	unsigned long count;
 	bool enabled = false;
 
 	spin_lock_irq(&dev->power.lock);
@@ -394,7 +400,10 @@ static ssize_t wakeup_abort_count_show(struct device *dev,
 		enabled = true;
 	}
 	spin_unlock_irq(&dev->power.lock);
-	return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
+
+	if (!enabled)
+		return sysfs_emit(buf, "\n");
+	return sysfs_emit(buf, "%lu\n", count);
 }
 
 static DEVICE_ATTR_RO(wakeup_abort_count);
@@ -403,7 +412,7 @@ static ssize_t wakeup_expire_count_show(struct device *dev,
 					struct device_attribute *attr,
 					char *buf)
 {
-	unsigned long count = 0;
+	unsigned long count;
 	bool enabled = false;
 
 	spin_lock_irq(&dev->power.lock);
@@ -412,7 +421,10 @@ static ssize_t wakeup_expire_count_show(struct device *dev,
 		enabled = true;
 	}
 	spin_unlock_irq(&dev->power.lock);
-	return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
+
+	if (!enabled)
+		return sysfs_emit(buf, "\n");
+	return sysfs_emit(buf, "%lu\n", count);
 }
 
 static DEVICE_ATTR_RO(wakeup_expire_count);
@@ -420,7 +432,7 @@ static DEVICE_ATTR_RO(wakeup_expire_count);
 static ssize_t wakeup_active_show(struct device *dev,
 				  struct device_attribute *attr, char *buf)
 {
-	unsigned int active = 0;
+	unsigned int active;
 	bool enabled = false;
 
 	spin_lock_irq(&dev->power.lock);
@@ -429,7 +441,10 @@ static ssize_t wakeup_active_show(struct device *dev,
 		enabled = true;
 	}
 	spin_unlock_irq(&dev->power.lock);
-	return enabled ? sprintf(buf, "%u\n", active) : sprintf(buf, "\n");
+
+	if (!enabled)
+		return sysfs_emit(buf, "\n");
+	return sysfs_emit(buf, "%u\n", active);
 }
 
 static DEVICE_ATTR_RO(wakeup_active);
@@ -438,7 +453,7 @@ static ssize_t wakeup_total_time_ms_show(struct device *dev,
 					 struct device_attribute *attr,
 					 char *buf)
 {
-	s64 msec = 0;
+	s64 msec;
 	bool enabled = false;
 
 	spin_lock_irq(&dev->power.lock);
@@ -447,7 +462,10 @@ static ssize_t wakeup_total_time_ms_show(struct device *dev,
 		enabled = true;
 	}
 	spin_unlock_irq(&dev->power.lock);
-	return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
+
+	if (!enabled)
+		return sysfs_emit(buf, "\n");
+	return sysfs_emit(buf, "%lld\n", msec);
 }
 
 static DEVICE_ATTR_RO(wakeup_total_time_ms);
@@ -455,7 +473,7 @@ static DEVICE_ATTR_RO(wakeup_total_time_ms);
 static ssize_t wakeup_max_time_ms_show(struct device *dev,
 				       struct device_attribute *attr, char *buf)
 {
-	s64 msec = 0;
+	s64 msec;
 	bool enabled = false;
 
 	spin_lock_irq(&dev->power.lock);
@@ -464,7 +482,10 @@ static ssize_t wakeup_max_time_ms_show(struct device *dev,
 		enabled = true;
 	}
 	spin_unlock_irq(&dev->power.lock);
-	return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
+
+	if (!enabled)
+		return sysfs_emit(buf, "\n");
+	return sysfs_emit(buf, "%lld\n", msec);
 }
 
 static DEVICE_ATTR_RO(wakeup_max_time_ms);
@@ -473,7 +494,7 @@ static ssize_t wakeup_last_time_ms_show(struct device *dev,
 					struct device_attribute *attr,
 					char *buf)
 {
-	s64 msec = 0;
+	s64 msec;
 	bool enabled = false;
 
 	spin_lock_irq(&dev->power.lock);
@@ -482,7 +503,10 @@ static ssize_t wakeup_last_time_ms_show(struct device *dev,
 		enabled = true;
 	}
 	spin_unlock_irq(&dev->power.lock);
-	return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
+
+	if (!enabled)
+		return sysfs_emit(buf, "\n");
+	return sysfs_emit(buf, "%lld\n", msec);
 }
 
 static DEVICE_ATTR_RO(wakeup_last_time_ms);
@@ -492,7 +516,7 @@ static ssize_t wakeup_prevent_sleep_time_ms_show(struct device *dev,
 						 struct device_attribute *attr,
 						 char *buf)
 {
-	s64 msec = 0;
+	s64 msec;
 	bool enabled = false;
 
 	spin_lock_irq(&dev->power.lock);
@@ -501,7 +525,10 @@ static ssize_t wakeup_prevent_sleep_time_ms_show(struct device *dev,
 		enabled = true;
 	}
 	spin_unlock_irq(&dev->power.lock);
-	return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
+
+	if (!enabled)
+		return sysfs_emit(buf, "\n");
+	return sysfs_emit(buf, "%lld\n", msec);
 }
 
 static DEVICE_ATTR_RO(wakeup_prevent_sleep_time_ms);

drivers/base/soc.c

@@ -17,9 +17,9 @@
 
 static DEFINE_IDA(soc_ida);
 
-static ssize_t soc_info_get(struct device *dev,
-			    struct device_attribute *attr,
-			    char *buf);
+/* Prototype to allow declarations of DEVICE_ATTR(<foo>) before soc_info_show */
+static ssize_t soc_info_show(struct device *dev, struct device_attribute *attr,
+			     char *buf);
 
 struct soc_device {
 	struct device dev;
@@ -31,10 +31,10 @@ static struct bus_type soc_bus_type = {
 	.name  = "soc",
 };
 
-static DEVICE_ATTR(machine,  S_IRUGO, soc_info_get,  NULL);
-static DEVICE_ATTR(family,   S_IRUGO, soc_info_get,  NULL);
-static DEVICE_ATTR(soc_id,   S_IRUGO, soc_info_get,  NULL);
-static DEVICE_ATTR(revision, S_IRUGO, soc_info_get,  NULL);
+static DEVICE_ATTR(machine,  0444, soc_info_show,  NULL);
+static DEVICE_ATTR(family,   0444, soc_info_show,  NULL);
+static DEVICE_ATTR(soc_id,   0444, soc_info_show,  NULL);
+static DEVICE_ATTR(revision, 0444, soc_info_show,  NULL);
 
 struct device *soc_device_to_device(struct soc_device *soc_dev)
 {
@@ -65,7 +65,7 @@ static umode_t soc_attribute_mode(struct kobject *kobj,
 	return 0;
 }
 
-static ssize_t soc_info_get(struct device *dev,
+static ssize_t soc_info_show(struct device *dev,
 			    struct device_attribute *attr,
 			    char *buf)
 {

drivers/base/topology.c

@@ -14,11 +14,11 @@
 #include <linux/hardirq.h>
 #include <linux/topology.h>
 
-#define define_id_show_func(name)				\
-static ssize_t name##_show(struct device *dev,			\
-		struct device_attribute *attr, char *buf)	\
-{								\
-	return sprintf(buf, "%d\n", topology_##name(dev->id));	\
+#define define_id_show_func(name)					\
+static ssize_t name##_show(struct device *dev,				\
+			   struct device_attribute *attr, char *buf)	\
+{									\
+	return sysfs_emit(buf, "%d\n", topology_##name(dev->id));	\
 }
 
 #define define_siblings_show_map(name, mask)				\