[PATCH V3 0/8] sysfs: drivers core: Add and use sysfs_emit and sysfs_emit

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* [PATCH V3 0/8] sysfs: drivers core: Add and use sysfs_emit and sysfs_emit_at
@ 2020-09-16 20:40 Joe Perches
  2020-09-16 20:40 ` [PATCH V3 2/8] drivers core: Use sysfs_emit and sysfs_emit_at for show(device *...) functions Joe Perches
                   ` (3 more replies)
  0 siblings, 4 replies; 5+ messages in thread
From: Joe Perches @ 2020-09-16 20:40 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Rafael J . Wysocki, linux-kernel, linux-pm, linux-mm
  Cc: Denis Efremov, Julia Lawall, Alex Dewar, linux-doc

Output defects can exist in sysfs content using sprintf and snprintf.

sprintf does not know the PAGE_SIZE maximum of the temporary buffer
used for outputting sysfs content and it's possible to overrun the
PAGE_SIZE buffer length.

Add a generic sysfs_emit function that knows that the size of the
temporary buffer and ensures that no overrun is done.

Add a generic sysfs_emit_at function that can be used in multiple
call situations that also ensures that no overrun is done.

V2: Add drivers core conversions
V3: Add a few more neatenings and conversions to drivers core
    Add mm hugetlb_report_node_meminfo conversion

Joe Perches (8):
  sysfs: Add sysfs_emit and sysfs_emit_at to format sysfs output
  drivers core: Use sysfs_emit and sysfs_emit_at for show(device *...) functions
  drivers core: Remove strcat uses around sysfs_emit and neaten
  drivers core: Reindent a couple uses around sysfs_emit
  drivers core: Miscellaneous changes for sysfs_emit
  mm: and drivers core: Convert hugetlb_report_node_meminfo to sysfs_emit
  drivers core: Use sysfs_emit for shared_cpu_map_show and shared_cpu_list_show
  drivers core: node: Use a more typical macro definition style for ACCESS_ATTR

 Documentation/filesystems/sysfs.rst     |   8 +-
 drivers/base/arch_topology.c            |   2 +-
 drivers/base/bus.c                      |   2 +-
 drivers/base/cacheinfo.c                |  49 ++--
 drivers/base/class.c                    |   2 +-
 drivers/base/core.c                     |  59 +++--
 drivers/base/cpu.c                      |  84 ++++---
 drivers/base/dd.c                       |   3 +-
 drivers/base/devcoredump.c              |   2 +-
 drivers/base/firmware_loader/fallback.c |   4 +-
 drivers/base/memory.c                   |  62 ++---
 drivers/base/node.c                     | 306 ++++++++++++------------
 drivers/base/platform.c                 |  17 +-
 drivers/base/power/sysfs.c              | 160 ++++++++-----
 drivers/base/power/wakeup_stats.c       |  17 +-
 drivers/base/soc.c                      |  64 +++--
 drivers/base/topology.c                 |  10 +-
 fs/sysfs/file.c                         |  55 +++++
 include/linux/hugetlb.h                 |   4 +-
 include/linux/sysfs.h                   |  15 ++
 mm/hugetlb.c                            |  18 +-
 21 files changed, 532 insertions(+), 411 deletions(-)

-- 
2.26.0


^ permalink raw reply	[flat|nested] 5+ messages in thread

* [PATCH V3 2/8] drivers core: Use sysfs_emit and sysfs_emit_at for show(device *...) functions
  2020-09-16 20:40 [PATCH V3 0/8] sysfs: drivers core: Add and use sysfs_emit and sysfs_emit_at Joe Perches
@ 2020-09-16 20:40 ` Joe Perches
  2020-09-16 20:40 ` [PATCH V3 3/8] drivers core: Remove strcat uses around sysfs_emit and neaten Joe Perches
                   ` (2 subsequent siblings)
  3 siblings, 0 replies; 5+ messages in thread
From: Joe Perches @ 2020-09-16 20:40 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Rafael J . Wysocki, Sudeep Holla,
	Luis Chamberlain, Len Brown, Pavel Machek
  Cc: Denis Efremov, Julia Lawall, Alex Dewar, linux-kernel, linux-pm

Convert the various sprintf fmaily calls in sysfs device show functions
to sysfs_emit and sysfs_emit_at for PAGE_SIZE buffer safety.

Done with:

$ spatch -sp-file sysfs_emit_dev.cocci --in-place --max-width=80 .

And cocci script:

$ cat sysfs_emit_dev.cocci
@@
identifier d_show;
identifier dev, attr, buf;
@@

ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	<...
	return
-	sprintf(buf,
+	sysfs_emit(buf,
	...);
	...>
}

@@
identifier d_show;
identifier dev, attr, buf;
@@

ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	<...
	return
-	snprintf(buf, PAGE_SIZE,
+	sysfs_emit(buf,
	...);
	...>
}

@@
identifier d_show;
identifier dev, attr, buf;
@@

ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	<...
	return
-	scnprintf(buf, PAGE_SIZE,
+	sysfs_emit(buf,
	...);
	...>
}

@@
identifier d_show;
identifier dev, attr, buf;
expression chr;
@@

ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	<...
	return
-	strcpy(buf, chr);
+	sysfs_emit(buf, chr);
	...>
}

@@
identifier d_show;
identifier dev, attr, buf;
identifier len;
@@

ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	<...
	len =
-	sprintf(buf,
+	sysfs_emit(buf,
	...);
	...>
	return len;
}

@@
identifier d_show;
identifier dev, attr, buf;
identifier len;
@@

ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	<...
	len =
-	snprintf(buf, PAGE_SIZE,
+	sysfs_emit(buf,
	...);
	...>
	return len;
}

@@
identifier d_show;
identifier dev, attr, buf;
identifier len;
@@

ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	<...
	len =
-	scnprintf(buf, PAGE_SIZE,
+	sysfs_emit(buf,
	...);
	...>
	return len;
}

@@
identifier d_show;
identifier dev, attr, buf;
identifier len;
@@

ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	<...
-	len += scnprintf(buf + len, PAGE_SIZE - len,
+	len += sysfs_emit_at(buf, len,
	...);
	...>
	return len;
}

@@
identifier d_show;
identifier dev, attr, buf;
expression chr;
@@

ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	...
-	strcpy(buf, chr);
-	return strlen(buf);
+	return sysfs_emit(buf, chr);
}

Signed-off-by: Joe Perches <joe@perches.com>
---
 drivers/base/arch_topology.c            |  2 +-
 drivers/base/cacheinfo.c                | 18 ++++-----
 drivers/base/core.c                     | 19 +++++-----
 drivers/base/cpu.c                      | 32 ++++++++--------
 drivers/base/dd.c                       |  2 +-
 drivers/base/firmware_loader/fallback.c |  2 +-
 drivers/base/memory.c                   | 24 ++++++------
 drivers/base/node.c                     | 28 +++++++-------
 drivers/base/platform.c                 |  4 +-
 drivers/base/power/sysfs.c              | 50 ++++++++++++-------------
 drivers/base/power/wakeup_stats.c       | 12 +++---
 drivers/base/soc.c                      | 10 ++---
 12 files changed, 102 insertions(+), 101 deletions(-)

diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c
index 75f72d684294..744d4618db33 100644
--- a/drivers/base/arch_topology.c
+++ b/drivers/base/arch_topology.c
@@ -71,7 +71,7 @@ static ssize_t cpu_capacity_show(struct device *dev,
 {
 	struct cpu *cpu = container_of(dev, struct cpu, dev);
 
-	return sprintf(buf, "%lu\n", topology_get_cpu_scale(cpu->dev.id));
+	return sysfs_emit(buf, "%lu\n", topology_get_cpu_scale(cpu->dev.id));
 }
 
 static void update_topology_flags_workfn(struct work_struct *work);
diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c
index 8d553c92cd32..6a8c2b5881be 100644
--- a/drivers/base/cacheinfo.c
+++ b/drivers/base/cacheinfo.c
@@ -377,7 +377,7 @@ static ssize_t size_show(struct device *dev,
 {
 	struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 
-	return sprintf(buf, "%uK\n", this_leaf->size >> 10);
+	return sysfs_emit(buf, "%uK\n", this_leaf->size >> 10);
 }
 
 static ssize_t shared_cpumap_show_func(struct device *dev, bool list, char *buf)
@@ -407,11 +407,11 @@ static ssize_t type_show(struct device *dev,
 
 	switch (this_leaf->type) {
 	case CACHE_TYPE_DATA:
-		return sprintf(buf, "Data\n");
+		return sysfs_emit(buf, "Data\n");
 	case CACHE_TYPE_INST:
-		return sprintf(buf, "Instruction\n");
+		return sysfs_emit(buf, "Instruction\n");
 	case CACHE_TYPE_UNIFIED:
-		return sprintf(buf, "Unified\n");
+		return sysfs_emit(buf, "Unified\n");
 	default:
 		return -EINVAL;
 	}
@@ -425,11 +425,11 @@ static ssize_t allocation_policy_show(struct device *dev,
 	int n = 0;
 
 	if ((ci_attr & CACHE_READ_ALLOCATE) && (ci_attr & CACHE_WRITE_ALLOCATE))
-		n = sprintf(buf, "ReadWriteAllocate\n");
+		n = sysfs_emit(buf, "ReadWriteAllocate\n");
 	else if (ci_attr & CACHE_READ_ALLOCATE)
-		n = sprintf(buf, "ReadAllocate\n");
+		n = sysfs_emit(buf, "ReadAllocate\n");
 	else if (ci_attr & CACHE_WRITE_ALLOCATE)
-		n = sprintf(buf, "WriteAllocate\n");
+		n = sysfs_emit(buf, "WriteAllocate\n");
 	return n;
 }
 
@@ -441,9 +441,9 @@ static ssize_t write_policy_show(struct device *dev,
 	int n = 0;
 
 	if (ci_attr & CACHE_WRITE_THROUGH)
-		n = sprintf(buf, "WriteThrough\n");
+		n = sysfs_emit(buf, "WriteThrough\n");
 	else if (ci_attr & CACHE_WRITE_BACK)
-		n = sprintf(buf, "WriteBack\n");
+		n = sysfs_emit(buf, "WriteBack\n");
 	return n;
 }
 
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 8dd753539c06..e17e8e941462 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -259,7 +259,7 @@ static ssize_t status_show(struct device *dev,
 	default:
 		status = "unknown"; break;
 	}
-	return sprintf(buf, "%s\n", status);
+	return sysfs_emit(buf, "%s\n", status);
 }
 static DEVICE_ATTR_RO(status);
 
@@ -276,7 +276,7 @@ static ssize_t auto_remove_on_show(struct device *dev,
 	else
 		str = "never";
 
-	return sprintf(buf, "%s\n", str);
+	return sysfs_emit(buf, "%s\n", str);
 }
 static DEVICE_ATTR_RO(auto_remove_on);
 
@@ -285,7 +285,7 @@ static ssize_t runtime_pm_show(struct device *dev,
 {
 	struct device_link *link = to_devlink(dev);
 
-	return sprintf(buf, "%d\n", !!(link->flags & DL_FLAG_PM_RUNTIME));
+	return sysfs_emit(buf, "%d\n", !!(link->flags & DL_FLAG_PM_RUNTIME));
 }
 static DEVICE_ATTR_RO(runtime_pm);
 
@@ -294,7 +294,8 @@ static ssize_t sync_state_only_show(struct device *dev,
 {
 	struct device_link *link = to_devlink(dev);
 
-	return sprintf(buf, "%d\n", !!(link->flags & DL_FLAG_SYNC_STATE_ONLY));
+	return sysfs_emit(buf, "%d\n",
+			  !!(link->flags & DL_FLAG_SYNC_STATE_ONLY));
 }
 static DEVICE_ATTR_RO(sync_state_only);
 
@@ -1059,7 +1060,7 @@ static ssize_t waiting_for_supplier_show(struct device *dev,
 	      && dev->links.need_for_probe;
 	mutex_unlock(&wfs_lock);
 	device_unlock(dev);
-	return sprintf(buf, "%u\n", val);
+	return sysfs_emit(buf, "%u\n", val);
 }
 static DEVICE_ATTR_RO(waiting_for_supplier);
 
@@ -1709,7 +1710,7 @@ ssize_t device_show_ulong(struct device *dev,
 			  char *buf)
 {
 	struct dev_ext_attribute *ea = to_ext_attr(attr);
-	return snprintf(buf, PAGE_SIZE, "%lx\n", *(unsigned long *)(ea->var));
+	return sysfs_emit(buf, "%lx\n", *(unsigned long *)(ea->var));
 }
 EXPORT_SYMBOL_GPL(device_show_ulong);
 
@@ -1739,7 +1740,7 @@ ssize_t device_show_int(struct device *dev,
 {
 	struct dev_ext_attribute *ea = to_ext_attr(attr);
 
-	return snprintf(buf, PAGE_SIZE, "%d\n", *(int *)(ea->var));
+	return sysfs_emit(buf, "%d\n", *(int *)(ea->var));
 }
 EXPORT_SYMBOL_GPL(device_show_int);
 
@@ -1760,7 +1761,7 @@ ssize_t device_show_bool(struct device *dev, struct device_attribute *attr,
 {
 	struct dev_ext_attribute *ea = to_ext_attr(attr);
 
-	return snprintf(buf, PAGE_SIZE, "%d\n", *(bool *)(ea->var));
+	return sysfs_emit(buf, "%d\n", *(bool *)(ea->var));
 }
 EXPORT_SYMBOL_GPL(device_show_bool);
 
@@ -1992,7 +1993,7 @@ static ssize_t online_show(struct device *dev, struct device_attribute *attr,
 	device_lock(dev);
 	val = !dev->offline;
 	device_unlock(dev);
-	return sprintf(buf, "%u\n", val);
+	return sysfs_emit(buf, "%u\n", val);
 }
 
 static ssize_t online_store(struct device *dev, struct device_attribute *attr,
diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index d2136ab9b14a..232f8146a8c4 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -156,7 +156,7 @@ 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 = sprintf(buf, "%Lx\n", addr);
+	rc = sysfs_emit(buf, "%Lx\n", addr);
 	return rc;
 }
 static DEVICE_ATTR(crash_notes, 0400, show_crash_notes, NULL);
@@ -167,7 +167,7 @@ static ssize_t show_crash_notes_size(struct device *dev,
 {
 	ssize_t rc;
 
-	rc = sprintf(buf, "%zu\n", sizeof(note_buf_t));
+	rc = sysfs_emit(buf, "%zu\n", sizeof(note_buf_t));
 	return rc;
 }
 static DEVICE_ATTR(crash_notes_size, 0400, show_crash_notes_size, NULL);
@@ -231,7 +231,7 @@ static struct cpu_attr cpu_attrs[] = {
 static ssize_t print_cpus_kernel_max(struct device *dev,
 				     struct device_attribute *attr, char *buf)
 {
-	return sprintf(buf, "%d\n", NR_CPUS - 1);
+	return sysfs_emit(buf, "%d\n", NR_CPUS - 1);
 }
 static DEVICE_ATTR(kernel_max, 0444, print_cpus_kernel_max, NULL);
 
@@ -279,7 +279,7 @@ static ssize_t print_cpus_isolated(struct device *dev,
 
 	cpumask_andnot(isolated, cpu_possible_mask,
 		       housekeeping_cpumask(HK_FLAG_DOMAIN));
-	n = sprintf(buf, "%*pbl\n", cpumask_pr_args(isolated));
+	n = sysfs_emit(buf, "%*pbl\n", cpumask_pr_args(isolated));
 
 	free_cpumask_var(isolated);
 
@@ -291,7 +291,7 @@ 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)
 {
-	return sprintf(buf, "%*pbl\n", cpumask_pr_args(tick_nohz_full_mask));
+	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
@@ -323,8 +323,8 @@ static ssize_t print_cpu_modalias(struct device *dev,
 	ssize_t n;
 	u32 i;
 
-	n = sprintf(buf, "cpu:type:" CPU_FEATURE_TYPEFMT ":feature:",
-		    CPU_FEATURE_TYPEVAL);
+	n = sysfs_emit(buf, "cpu:type:" CPU_FEATURE_TYPEFMT ":feature:",
+		       CPU_FEATURE_TYPEVAL);
 
 	for (i = 0; i < MAX_CPU_FEATURES; i++)
 		if (cpu_have_feature(i)) {
@@ -516,56 +516,56 @@ static void __init cpu_dev_register_generic(void)
 ssize_t __weak cpu_show_meltdown(struct device *dev,
 				 struct device_attribute *attr, char *buf)
 {
-	return sprintf(buf, "Not affected\n");
+	return sysfs_emit(buf, "Not affected\n");
 }
 
 ssize_t __weak cpu_show_spectre_v1(struct device *dev,
 				   struct device_attribute *attr, char *buf)
 {
-	return sprintf(buf, "Not affected\n");
+	return sysfs_emit(buf, "Not affected\n");
 }
 
 ssize_t __weak cpu_show_spectre_v2(struct device *dev,
 				   struct device_attribute *attr, char *buf)
 {
-	return sprintf(buf, "Not affected\n");
+	return sysfs_emit(buf, "Not affected\n");
 }
 
 ssize_t __weak cpu_show_spec_store_bypass(struct device *dev,
 					  struct device_attribute *attr, char *buf)
 {
-	return sprintf(buf, "Not affected\n");
+	return sysfs_emit(buf, "Not affected\n");
 }
 
 ssize_t __weak cpu_show_l1tf(struct device *dev,
 			     struct device_attribute *attr, char *buf)
 {
-	return sprintf(buf, "Not affected\n");
+	return sysfs_emit(buf, "Not affected\n");
 }
 
 ssize_t __weak cpu_show_mds(struct device *dev,
 			    struct device_attribute *attr, char *buf)
 {
-	return sprintf(buf, "Not affected\n");
+	return sysfs_emit(buf, "Not affected\n");
 }
 
 ssize_t __weak cpu_show_tsx_async_abort(struct device *dev,
 					struct device_attribute *attr,
 					char *buf)
 {
-	return sprintf(buf, "Not affected\n");
+	return sysfs_emit(buf, "Not affected\n");
 }
 
 ssize_t __weak cpu_show_itlb_multihit(struct device *dev,
 			    struct device_attribute *attr, char *buf)
 {
-	return sprintf(buf, "Not affected\n");
+	return sysfs_emit(buf, "Not affected\n");
 }
 
 ssize_t __weak cpu_show_srbds(struct device *dev,
 			      struct device_attribute *attr, char *buf)
 {
-	return sprintf(buf, "Not affected\n");
+	return sysfs_emit(buf, "Not affected\n");
 }
 
 static DEVICE_ATTR(meltdown, 0444, cpu_show_meltdown, NULL);
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 6e7319ca5bde..123a1c3e9f18 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -486,7 +486,7 @@ static ssize_t state_synced_show(struct device *dev,
 	device_lock(dev);
 	val = dev->state_synced;
 	device_unlock(dev);
-	return sprintf(buf, "%u\n", val);
+	return sysfs_emit(buf, "%u\n", val);
 }
 static DEVICE_ATTR_RO(state_synced);
 
diff --git a/drivers/base/firmware_loader/fallback.c b/drivers/base/firmware_loader/fallback.c
index 283ca2de76d4..7e9598a1577a 100644
--- a/drivers/base/firmware_loader/fallback.c
+++ b/drivers/base/firmware_loader/fallback.c
@@ -219,7 +219,7 @@ static ssize_t firmware_loading_show(struct device *dev,
 		loading = fw_sysfs_loading(fw_sysfs->fw_priv);
 	mutex_unlock(&fw_lock);
 
-	return sprintf(buf, "%d\n", loading);
+	return sysfs_emit(buf, "%d\n", loading);
 }
 
 /**
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index b4c297dd0475..f5c0b64df2e5 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -119,7 +119,7 @@ static ssize_t phys_index_show(struct device *dev,
 	unsigned long phys_index;
 
 	phys_index = mem->start_section_nr / sections_per_block;
-	return sprintf(buf, "%08lx\n", phys_index);
+	return sysfs_emit(buf, "%08lx\n", phys_index);
 }
 
 /*
@@ -129,7 +129,7 @@ static ssize_t phys_index_show(struct device *dev,
 static ssize_t removable_show(struct device *dev, struct device_attribute *attr,
 			      char *buf)
 {
-	return sprintf(buf, "%d\n", (int)IS_ENABLED(CONFIG_MEMORY_HOTREMOVE));
+	return sysfs_emit(buf, "%d\n", (int)IS_ENABLED(CONFIG_MEMORY_HOTREMOVE));
 }
 
 /*
@@ -147,17 +147,17 @@ static ssize_t state_show(struct device *dev, struct device_attribute *attr,
 	 */
 	switch (mem->state) {
 	case MEM_ONLINE:
-		len = sprintf(buf, "online\n");
+		len = sysfs_emit(buf, "online\n");
 		break;
 	case MEM_OFFLINE:
-		len = sprintf(buf, "offline\n");
+		len = sysfs_emit(buf, "offline\n");
 		break;
 	case MEM_GOING_OFFLINE:
-		len = sprintf(buf, "going-offline\n");
+		len = sysfs_emit(buf, "going-offline\n");
 		break;
 	default:
-		len = sprintf(buf, "ERROR-UNKNOWN-%ld\n",
-				mem->state);
+		len = sysfs_emit(buf, "ERROR-UNKNOWN-%ld\n",
+				 mem->state);
 		WARN_ON(1);
 		break;
 	}
@@ -303,7 +303,7 @@ static ssize_t phys_device_show(struct device *dev,
 				struct device_attribute *attr, char *buf)
 {
 	struct memory_block *mem = to_memory_block(dev);
-	return sprintf(buf, "%d\n", mem->phys_device);
+	return sysfs_emit(buf, "%d\n", mem->phys_device);
 }
 
 #ifdef CONFIG_MEMORY_HOTREMOVE
@@ -341,7 +341,7 @@ static ssize_t valid_zones_show(struct device *dev,
 		default_zone = test_pages_in_a_zone(start_pfn,
 						    start_pfn + nr_pages);
 		if (!default_zone)
-			return sprintf(buf, "none\n");
+			return sysfs_emit(buf, "none\n");
 		strcat(buf, default_zone->name);
 		goto out;
 	}
@@ -374,7 +374,7 @@ static DEVICE_ATTR_RO(removable);
 static ssize_t block_size_bytes_show(struct device *dev,
 				     struct device_attribute *attr, char *buf)
 {
-	return sprintf(buf, "%lx\n", memory_block_size_bytes());
+	return sysfs_emit(buf, "%lx\n", memory_block_size_bytes());
 }
 
 static DEVICE_ATTR_RO(block_size_bytes);
@@ -386,8 +386,8 @@ static DEVICE_ATTR_RO(block_size_bytes);
 static ssize_t auto_online_blocks_show(struct device *dev,
 				       struct device_attribute *attr, char *buf)
 {
-	return sprintf(buf, "%s\n",
-		       online_type_to_str[memhp_default_online_type]);
+	return sysfs_emit(buf, "%s\n",
+			  online_type_to_str[memhp_default_online_type]);
 }
 
 static ssize_t auto_online_blocks_store(struct device *dev,
diff --git a/drivers/base/node.c b/drivers/base/node.c
index 9426b0f1f660..f6bde7acd5fe 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -370,7 +370,7 @@ static ssize_t node_read_meminfo(struct device *dev,
 	si_meminfo_node(&i, nid);
 	sreclaimable = node_page_state_pages(pgdat, NR_SLAB_RECLAIMABLE_B);
 	sunreclaimable = node_page_state_pages(pgdat, NR_SLAB_UNRECLAIMABLE_B);
-	n = sprintf(buf,
+	n = sysfs_emit(buf,
 		       "Node %d MemTotal:       %8lu kB\n"
 		       "Node %d MemFree:        %8lu kB\n"
 		       "Node %d MemUsed:        %8lu kB\n"
@@ -477,19 +477,19 @@ static DEVICE_ATTR(meminfo, S_IRUGO, node_read_meminfo, NULL);
 static ssize_t node_read_numastat(struct device *dev,
 				struct device_attribute *attr, char *buf)
 {
-	return sprintf(buf,
-		       "numa_hit %lu\n"
-		       "numa_miss %lu\n"
-		       "numa_foreign %lu\n"
-		       "interleave_hit %lu\n"
-		       "local_node %lu\n"
-		       "other_node %lu\n",
-		       sum_zone_numa_state(dev->id, NUMA_HIT),
-		       sum_zone_numa_state(dev->id, NUMA_MISS),
-		       sum_zone_numa_state(dev->id, NUMA_FOREIGN),
-		       sum_zone_numa_state(dev->id, NUMA_INTERLEAVE_HIT),
-		       sum_zone_numa_state(dev->id, NUMA_LOCAL),
-		       sum_zone_numa_state(dev->id, NUMA_OTHER));
+	return sysfs_emit(buf,
+			  "numa_hit %lu\n"
+			  "numa_miss %lu\n"
+			  "numa_foreign %lu\n"
+			  "interleave_hit %lu\n"
+			  "local_node %lu\n"
+			  "other_node %lu\n",
+			  sum_zone_numa_state(dev->id, NUMA_HIT),
+			  sum_zone_numa_state(dev->id, NUMA_MISS),
+			  sum_zone_numa_state(dev->id, NUMA_FOREIGN),
+			  sum_zone_numa_state(dev->id, NUMA_INTERLEAVE_HIT),
+			  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);
 
diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index d90d92e63903..f0f8cfcc3621 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -1084,7 +1084,7 @@ static ssize_t driver_override_show(struct device *dev,
 	ssize_t len;
 
 	device_lock(dev);
-	len = sprintf(buf, "%s\n", pdev->driver_override);
+	len = sysfs_emit(buf, "%s\n", pdev->driver_override);
 	device_unlock(dev);
 	return len;
 }
@@ -1093,7 +1093,7 @@ static DEVICE_ATTR_RW(driver_override);
 static ssize_t numa_node_show(struct device *dev,
 		struct device_attribute *attr, char *buf)
 {
-	return sprintf(buf, "%d\n", dev_to_node(dev));
+	return sysfs_emit(buf, "%d\n", dev_to_node(dev));
 }
 static DEVICE_ATTR_RO(numa_node);
 
diff --git a/drivers/base/power/sysfs.c b/drivers/base/power/sysfs.c
index c7b24812523c..4276b792d0aa 100644
--- a/drivers/base/power/sysfs.c
+++ b/drivers/base/power/sysfs.c
@@ -101,7 +101,7 @@ static const char ctrl_on[] = "on";
 static ssize_t control_show(struct device *dev, struct device_attribute *attr,
 			    char *buf)
 {
-	return sprintf(buf, "%s\n",
+	return sysfs_emit(buf, "%s\n",
 				dev->power.runtime_auto ? ctrl_auto : ctrl_on);
 }
 
@@ -127,7 +127,7 @@ static ssize_t runtime_active_time_show(struct device *dev,
 	int ret;
 	u64 tmp = pm_runtime_active_time(dev);
 	do_div(tmp, NSEC_PER_MSEC);
-	ret = sprintf(buf, "%llu\n", tmp);
+	ret = sysfs_emit(buf, "%llu\n", tmp);
 	return ret;
 }
 
@@ -139,7 +139,7 @@ static ssize_t runtime_suspended_time_show(struct device *dev,
 	int ret;
 	u64 tmp = pm_runtime_suspended_time(dev);
 	do_div(tmp, NSEC_PER_MSEC);
-	ret = sprintf(buf, "%llu\n", tmp);
+	ret = sysfs_emit(buf, "%llu\n", tmp);
 	return ret;
 }
 
@@ -172,7 +172,7 @@ static ssize_t runtime_status_show(struct device *dev,
 			return -EIO;
 		}
 	}
-	return sprintf(buf, p);
+	return sysfs_emit(buf, p);
 }
 
 static DEVICE_ATTR_RO(runtime_status);
@@ -182,7 +182,7 @@ static ssize_t autosuspend_delay_ms_show(struct device *dev,
 {
 	if (!dev->power.use_autosuspend)
 		return -EIO;
-	return sprintf(buf, "%d\n", dev->power.autosuspend_delay);
+	return sysfs_emit(buf, "%d\n", dev->power.autosuspend_delay);
 }
 
 static ssize_t autosuspend_delay_ms_store(struct device *dev,
@@ -211,11 +211,11 @@ static ssize_t pm_qos_resume_latency_us_show(struct device *dev,
 	s32 value = dev_pm_qos_requested_resume_latency(dev);
 
 	if (value == 0)
-		return sprintf(buf, "n/a\n");
+		return sysfs_emit(buf, "n/a\n");
 	if (value == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT)
 		value = 0;
 
-	return sprintf(buf, "%d\n", value);
+	return sysfs_emit(buf, "%d\n", value);
 }
 
 static ssize_t pm_qos_resume_latency_us_store(struct device *dev,
@@ -255,11 +255,11 @@ static ssize_t pm_qos_latency_tolerance_us_show(struct device *dev,
 	s32 value = dev_pm_qos_get_user_latency_tolerance(dev);
 
 	if (value < 0)
-		return sprintf(buf, "auto\n");
+		return sysfs_emit(buf, "auto\n");
 	if (value == PM_QOS_LATENCY_ANY)
-		return sprintf(buf, "any\n");
+		return sysfs_emit(buf, "any\n");
 
-	return sprintf(buf, "%d\n", value);
+	return sysfs_emit(buf, "%d\n", value);
 }
 
 static ssize_t pm_qos_latency_tolerance_us_store(struct device *dev,
@@ -291,8 +291,8 @@ static ssize_t pm_qos_no_power_off_show(struct device *dev,
 					struct device_attribute *attr,
 					char *buf)
 {
-	return sprintf(buf, "%d\n", !!(dev_pm_qos_requested_flags(dev)
-					& PM_QOS_FLAG_NO_POWER_OFF));
+	return sysfs_emit(buf, "%d\n", !!(dev_pm_qos_requested_flags(dev)
+					  & PM_QOS_FLAG_NO_POWER_OFF));
 }
 
 static ssize_t pm_qos_no_power_off_store(struct device *dev,
@@ -320,9 +320,9 @@ static const char _disabled[] = "disabled";
 static ssize_t wakeup_show(struct device *dev, struct device_attribute *attr,
 			   char *buf)
 {
-	return sprintf(buf, "%s\n", device_can_wakeup(dev)
-		? (device_may_wakeup(dev) ? _enabled : _disabled)
-		: "");
+	return sysfs_emit(buf, "%s\n", device_can_wakeup(dev)
+			  ? (device_may_wakeup(dev) ? _enabled : _disabled)
+			  : "");
 }
 
 static ssize_t wakeup_store(struct device *dev, struct device_attribute *attr,
@@ -522,7 +522,7 @@ static inline int dpm_sysfs_wakeup_change_owner(struct device *dev, kuid_t kuid,
 static ssize_t runtime_usage_show(struct device *dev,
 				  struct device_attribute *attr, char *buf)
 {
-	return sprintf(buf, "%d\n", atomic_read(&dev->power.usage_count));
+	return sysfs_emit(buf, "%d\n", atomic_read(&dev->power.usage_count));
 }
 static DEVICE_ATTR_RO(runtime_usage);
 
@@ -530,8 +530,8 @@ static ssize_t runtime_active_kids_show(struct device *dev,
 					struct device_attribute *attr,
 					char *buf)
 {
-	return sprintf(buf, "%d\n", dev->power.ignore_children ?
-		0 : atomic_read(&dev->power.child_count));
+	return sysfs_emit(buf, "%d\n", dev->power.ignore_children ?
+			  0 : atomic_read(&dev->power.child_count));
 }
 static DEVICE_ATTR_RO(runtime_active_kids);
 
@@ -539,12 +539,12 @@ static ssize_t runtime_enabled_show(struct device *dev,
 				    struct device_attribute *attr, char *buf)
 {
 	if (dev->power.disable_depth && (dev->power.runtime_auto == false))
-		return sprintf(buf, "disabled & forbidden\n");
+		return sysfs_emit(buf, "disabled & forbidden\n");
 	if (dev->power.disable_depth)
-		return sprintf(buf, "disabled\n");
+		return sysfs_emit(buf, "disabled\n");
 	if (dev->power.runtime_auto == false)
-		return sprintf(buf, "forbidden\n");
-	return sprintf(buf, "enabled\n");
+		return sysfs_emit(buf, "forbidden\n");
+	return sysfs_emit(buf, "enabled\n");
 }
 static DEVICE_ATTR_RO(runtime_enabled);
 
@@ -552,9 +552,9 @@ static DEVICE_ATTR_RO(runtime_enabled);
 static ssize_t async_show(struct device *dev, struct device_attribute *attr,
 			  char *buf)
 {
-	return sprintf(buf, "%s\n",
-			device_async_suspend_enabled(dev) ?
-				_enabled : _disabled);
+	return sysfs_emit(buf, "%s\n",
+			  device_async_suspend_enabled(dev) ?
+			  _enabled : _disabled);
 }
 
 static ssize_t async_store(struct device *dev, struct device_attribute *attr,
diff --git a/drivers/base/power/wakeup_stats.c b/drivers/base/power/wakeup_stats.c
index c7734914d914..5568e25d7c9c 100644
--- a/drivers/base/power/wakeup_stats.c
+++ b/drivers/base/power/wakeup_stats.c
@@ -42,7 +42,7 @@ static ssize_t active_time_ms_show(struct device *dev,
 	ktime_t active_time =
 		ws->active ? ktime_sub(ktime_get(), ws->last_time) : 0;
 
-	return sprintf(buf, "%lld\n", ktime_to_ms(active_time));
+	return sysfs_emit(buf, "%lld\n", ktime_to_ms(active_time));
 }
 static DEVICE_ATTR_RO(active_time_ms);
 
@@ -57,7 +57,7 @@ static ssize_t total_time_ms_show(struct device *dev,
 		active_time = ktime_sub(ktime_get(), ws->last_time);
 		total_time = ktime_add(total_time, active_time);
 	}
-	return sprintf(buf, "%lld\n", ktime_to_ms(total_time));
+	return sysfs_emit(buf, "%lld\n", ktime_to_ms(total_time));
 }
 static DEVICE_ATTR_RO(total_time_ms);
 
@@ -73,7 +73,7 @@ static ssize_t max_time_ms_show(struct device *dev,
 		if (active_time > max_time)
 			max_time = active_time;
 	}
-	return sprintf(buf, "%lld\n", ktime_to_ms(max_time));
+	return sysfs_emit(buf, "%lld\n", ktime_to_ms(max_time));
 }
 static DEVICE_ATTR_RO(max_time_ms);
 
@@ -82,7 +82,7 @@ static ssize_t last_change_ms_show(struct device *dev,
 {
 	struct wakeup_source *ws = dev_get_drvdata(dev);
 
-	return sprintf(buf, "%lld\n", ktime_to_ms(ws->last_time));
+	return sysfs_emit(buf, "%lld\n", ktime_to_ms(ws->last_time));
 }
 static DEVICE_ATTR_RO(last_change_ms);
 
@@ -91,7 +91,7 @@ static ssize_t name_show(struct device *dev, struct device_attribute *attr,
 {
 	struct wakeup_source *ws = dev_get_drvdata(dev);
 
-	return sprintf(buf, "%s\n", ws->name);
+	return sysfs_emit(buf, "%s\n", ws->name);
 }
 static DEVICE_ATTR_RO(name);
 
@@ -106,7 +106,7 @@ static ssize_t prevent_suspend_time_ms_show(struct device *dev,
 		prevent_sleep_time = ktime_add(prevent_sleep_time,
 			ktime_sub(ktime_get(), ws->start_prevent_time));
 	}
-	return sprintf(buf, "%lld\n", ktime_to_ms(prevent_sleep_time));
+	return sysfs_emit(buf, "%lld\n", ktime_to_ms(prevent_sleep_time));
 }
 static DEVICE_ATTR_RO(prevent_suspend_time_ms);
 
diff --git a/drivers/base/soc.c b/drivers/base/soc.c
index a5bae551167d..fc6536a7eac6 100644
--- a/drivers/base/soc.c
+++ b/drivers/base/soc.c
@@ -76,15 +76,15 @@ static ssize_t soc_info_get(struct device *dev,
 	struct soc_device *soc_dev = container_of(dev, struct soc_device, dev);
 
 	if (attr == &dev_attr_machine)
-		return sprintf(buf, "%s\n", soc_dev->attr->machine);
+		return sysfs_emit(buf, "%s\n", soc_dev->attr->machine);
 	if (attr == &dev_attr_family)
-		return sprintf(buf, "%s\n", soc_dev->attr->family);
+		return sysfs_emit(buf, "%s\n", soc_dev->attr->family);
 	if (attr == &dev_attr_revision)
-		return sprintf(buf, "%s\n", soc_dev->attr->revision);
+		return sysfs_emit(buf, "%s\n", soc_dev->attr->revision);
 	if (attr == &dev_attr_serial_number)
-		return sprintf(buf, "%s\n", soc_dev->attr->serial_number);
+		return sysfs_emit(buf, "%s\n", soc_dev->attr->serial_number);
 	if (attr == &dev_attr_soc_id)
-		return sprintf(buf, "%s\n", soc_dev->attr->soc_id);
+		return sysfs_emit(buf, "%s\n", soc_dev->attr->soc_id);
 
 	return -EINVAL;
 
-- 
2.26.0


^ permalink raw reply related	[flat|nested] 5+ messages in thread

* [PATCH V3 3/8] drivers core: Remove strcat uses around sysfs_emit and neaten
  2020-09-16 20:40 [PATCH V3 0/8] sysfs: drivers core: Add and use sysfs_emit and sysfs_emit_at Joe Perches
  2020-09-16 20:40 ` [PATCH V3 2/8] drivers core: Use sysfs_emit and sysfs_emit_at for show(device *...) functions Joe Perches
@ 2020-09-16 20:40 ` Joe Perches
  2020-09-16 20:40 ` [PATCH V3 4/8] drivers core: Reindent a couple uses around sysfs_emit Joe Perches
  2020-09-16 20:40 ` [PATCH V3 5/8] drivers core: Miscellaneous changes for sysfs_emit Joe Perches
  3 siblings, 0 replies; 5+ messages in thread
From: Joe Perches @ 2020-09-16 20:40 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Rafael J . Wysocki, Len Brown, Pavel Machek
  Cc: Denis Efremov, Julia Lawall, Alex Dewar, linux-kernel, linux-pm

strcat is no longer necessary for sysfs_emit and sysfs_emit_at uses.

Convert the strcat uses to sysfs_emit calls and neaten other block
uses of direct returns to use an intermediate const char *.

Signed-off-by: Joe Perches <joe@perches.com>
---
 drivers/base/cacheinfo.c   | 25 +++++++++++++-------
 drivers/base/core.c        | 10 ++++----
 drivers/base/memory.c      | 47 ++++++++++++++++++--------------------
 drivers/base/power/sysfs.c | 23 +++++++++++--------
 4 files changed, 58 insertions(+), 47 deletions(-)

diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c
index 6a8c2b5881be..96f8af414a48 100644
--- a/drivers/base/cacheinfo.c
+++ b/drivers/base/cacheinfo.c
@@ -404,17 +404,23 @@ static ssize_t type_show(struct device *dev,
 			 struct device_attribute *attr, char *buf)
 {
 	struct cacheinfo *this_leaf = dev_get_drvdata(dev);
+	const char *output;
 
 	switch (this_leaf->type) {
 	case CACHE_TYPE_DATA:
-		return sysfs_emit(buf, "Data\n");
+		output = "Data";
+		break;
 	case CACHE_TYPE_INST:
-		return sysfs_emit(buf, "Instruction\n");
+		output = "Instruction";
+		break;
 	case CACHE_TYPE_UNIFIED:
-		return sysfs_emit(buf, "Unified\n");
+		output = "Unified";
+		break;
 	default:
 		return -EINVAL;
 	}
+
+	return sysfs_emit(buf, "%s\n", output);
 }
 
 static ssize_t allocation_policy_show(struct device *dev,
@@ -422,15 +428,18 @@ static ssize_t allocation_policy_show(struct device *dev,
 {
 	struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 	unsigned int ci_attr = this_leaf->attributes;
-	int n = 0;
+	const char *output;
 
 	if ((ci_attr & CACHE_READ_ALLOCATE) && (ci_attr & CACHE_WRITE_ALLOCATE))
-		n = sysfs_emit(buf, "ReadWriteAllocate\n");
+		output = "ReadWriteAllocate";
 	else if (ci_attr & CACHE_READ_ALLOCATE)
-		n = sysfs_emit(buf, "ReadAllocate\n");
+		output = "ReadAllocate";
 	else if (ci_attr & CACHE_WRITE_ALLOCATE)
-		n = sysfs_emit(buf, "WriteAllocate\n");
-	return n;
+		output = "WriteAllocate";
+	else
+		return 0;
+
+	return sysfs_emit(buf, "%s\n", output);
 }
 
 static ssize_t write_policy_show(struct device *dev,
diff --git a/drivers/base/core.c b/drivers/base/core.c
index e17e8e941462..c5d2cc8bb8b0 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -267,16 +267,16 @@ static ssize_t auto_remove_on_show(struct device *dev,
 				   struct device_attribute *attr, char *buf)
 {
 	struct device_link *link = to_devlink(dev);
-	char *str;
+	const char *output;
 
 	if (link->flags & DL_FLAG_AUTOREMOVE_SUPPLIER)
-		str = "supplier unbind";
+		output = "supplier unbind";
 	else if (link->flags & DL_FLAG_AUTOREMOVE_CONSUMER)
-		str = "consumer unbind";
+		output = "consumer unbind";
 	else
-		str = "never";
+		output = "never";
 
-	return sysfs_emit(buf, "%s\n", str);
+	return sysfs_emit(buf, "%s\n", output);
 }
 static DEVICE_ATTR_RO(auto_remove_on);
 
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index f5c0b64df2e5..7abf9eb8bff0 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -139,7 +139,7 @@ static ssize_t state_show(struct device *dev, struct device_attribute *attr,
 			  char *buf)
 {
 	struct memory_block *mem = to_memory_block(dev);
-	ssize_t len = 0;
+	const char *output;
 
 	/*
 	 * We can probably put these states in a nice little array
@@ -147,22 +147,20 @@ static ssize_t state_show(struct device *dev, struct device_attribute *attr,
 	 */
 	switch (mem->state) {
 	case MEM_ONLINE:
-		len = sysfs_emit(buf, "online\n");
+		output = "online";
 		break;
 	case MEM_OFFLINE:
-		len = sysfs_emit(buf, "offline\n");
+		output = "offline";
 		break;
 	case MEM_GOING_OFFLINE:
-		len = sysfs_emit(buf, "going-offline\n");
+		output = "going-offline";
 		break;
 	default:
-		len = sysfs_emit(buf, "ERROR-UNKNOWN-%ld\n",
-				 mem->state);
 		WARN_ON(1);
-		break;
+		return sysfs_emit(buf, "ERROR-UNKNOWN-%ld\n", mem->state);
 	}
 
-	return len;
+	return sysfs_emit(buf, "%s\n", output);
 }
 
 int memory_notify(unsigned long val, void *v)
@@ -307,17 +305,16 @@ static ssize_t phys_device_show(struct device *dev,
 }
 
 #ifdef CONFIG_MEMORY_HOTREMOVE
-static void print_allowed_zone(char *buf, int nid, unsigned long start_pfn,
-		unsigned long nr_pages, int online_type,
-		struct zone *default_zone)
+static int print_allowed_zone(char *buf, int len, int nid,
+			      unsigned long start_pfn, unsigned long nr_pages,
+			      int online_type, struct zone *default_zone)
 {
 	struct zone *zone;
 
 	zone = zone_for_pfn_range(online_type, nid, start_pfn, nr_pages);
-	if (zone != default_zone) {
-		strcat(buf, " ");
-		strcat(buf, zone->name);
-	}
+	if (zone == default_zone)
+		return 0;
+	return sysfs_emit_at(buf, len, " %s", zone->name);
 }
 
 static ssize_t valid_zones_show(struct device *dev,
@@ -327,6 +324,7 @@ static ssize_t valid_zones_show(struct device *dev,
 	unsigned long start_pfn = section_nr_to_pfn(mem->start_section_nr);
 	unsigned long nr_pages = PAGES_PER_SECTION * sections_per_block;
 	struct zone *default_zone;
+	int len = 0;
 	int nid;
 
 	/*
@@ -341,24 +339,23 @@ static ssize_t valid_zones_show(struct device *dev,
 		default_zone = test_pages_in_a_zone(start_pfn,
 						    start_pfn + nr_pages);
 		if (!default_zone)
-			return sysfs_emit(buf, "none\n");
-		strcat(buf, default_zone->name);
+			return sysfs_emit(buf, "%s\n", "none");
+		len += sysfs_emit_at(buf, len, "%s", default_zone->name);
 		goto out;
 	}
 
 	nid = mem->nid;
 	default_zone = zone_for_pfn_range(MMOP_ONLINE, nid, start_pfn,
 					  nr_pages);
-	strcat(buf, default_zone->name);
 
-	print_allowed_zone(buf, nid, start_pfn, nr_pages, MMOP_ONLINE_KERNEL,
-			default_zone);
-	print_allowed_zone(buf, nid, start_pfn, nr_pages, MMOP_ONLINE_MOVABLE,
-			default_zone);
+	len += sysfs_emit_at(buf, len, "%s", default_zone->name);
+	len += print_allowed_zone(buf, len, nid, start_pfn, nr_pages,
+				  MMOP_ONLINE_KERNEL, default_zone);
+	len += print_allowed_zone(buf, len, nid, start_pfn, nr_pages,
+				  MMOP_ONLINE_MOVABLE, default_zone);
 out:
-	strcat(buf, "\n");
-
-	return strlen(buf);
+	len += sysfs_emit_at(buf, len, "%s", "\n");
+	return len;
 }
 static DEVICE_ATTR_RO(valid_zones);
 #endif
diff --git a/drivers/base/power/sysfs.c b/drivers/base/power/sysfs.c
index 4276b792d0aa..61e16786f6c5 100644
--- a/drivers/base/power/sysfs.c
+++ b/drivers/base/power/sysfs.c
@@ -255,9 +255,9 @@ static ssize_t pm_qos_latency_tolerance_us_show(struct device *dev,
 	s32 value = dev_pm_qos_get_user_latency_tolerance(dev);
 
 	if (value < 0)
-		return sysfs_emit(buf, "auto\n");
+		return sysfs_emit(buf, "%s\n", "auto");
 	if (value == PM_QOS_LATENCY_ANY)
-		return sysfs_emit(buf, "any\n");
+		return sysfs_emit(buf, "%s\n", "any");
 
 	return sysfs_emit(buf, "%d\n", value);
 }
@@ -538,13 +538,18 @@ static DEVICE_ATTR_RO(runtime_active_kids);
 static ssize_t runtime_enabled_show(struct device *dev,
 				    struct device_attribute *attr, char *buf)
 {
-	if (dev->power.disable_depth && (dev->power.runtime_auto == false))
-		return sysfs_emit(buf, "disabled & forbidden\n");
-	if (dev->power.disable_depth)
-		return sysfs_emit(buf, "disabled\n");
-	if (dev->power.runtime_auto == false)
-		return sysfs_emit(buf, "forbidden\n");
-	return sysfs_emit(buf, "enabled\n");
+	const char *output;
+
+	if (dev->power.disable_depth && !dev->power.runtime_auto)
+		output = "disabled & forbidden";
+	else if (dev->power.disable_depth)
+		output = "disabled";
+	else if (!dev->power.runtime_auto)
+		output = "forbidden";
+	else
+		output = "enabled";
+
+	return sysfs_emit(buf, "%s\n", output);
 }
 static DEVICE_ATTR_RO(runtime_enabled);
 
-- 
2.26.0


^ permalink raw reply related	[flat|nested] 5+ messages in thread

* [PATCH V3 4/8] drivers core: Reindent a couple uses around sysfs_emit
  2020-09-16 20:40 [PATCH V3 0/8] sysfs: drivers core: Add and use sysfs_emit and sysfs_emit_at Joe Perches
  2020-09-16 20:40 ` [PATCH V3 2/8] drivers core: Use sysfs_emit and sysfs_emit_at for show(device *...) functions Joe Perches
  2020-09-16 20:40 ` [PATCH V3 3/8] drivers core: Remove strcat uses around sysfs_emit and neaten Joe Perches
@ 2020-09-16 20:40 ` Joe Perches
  2020-09-16 20:40 ` [PATCH V3 5/8] drivers core: Miscellaneous changes for sysfs_emit Joe Perches
  3 siblings, 0 replies; 5+ messages in thread
From: Joe Perches @ 2020-09-16 20:40 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Rafael J . Wysocki, Pavel Machek, Len Brown
  Cc: Denis Efremov, Julia Lawall, Alex Dewar, linux-kernel, linux-pm

Just a couple of whitespace realignment to open parenthesis for
multi-line statements.

Signed-off-by: Joe Perches <joe@perches.com>
---
 drivers/base/node.c        | 4 ++--
 drivers/base/power/sysfs.c | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/base/node.c b/drivers/base/node.c
index f6bde7acd5fe..b2dcca375da6 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -386,9 +386,9 @@ static ssize_t node_read_meminfo(struct device *dev,
 		       nid, K(i.freeram),
 		       nid, K(i.totalram - i.freeram),
 		       nid, K(node_page_state(pgdat, NR_ACTIVE_ANON) +
-				node_page_state(pgdat, NR_ACTIVE_FILE)),
+			      node_page_state(pgdat, NR_ACTIVE_FILE)),
 		       nid, K(node_page_state(pgdat, NR_INACTIVE_ANON) +
-				node_page_state(pgdat, NR_INACTIVE_FILE)),
+			      node_page_state(pgdat, NR_INACTIVE_FILE)),
 		       nid, K(node_page_state(pgdat, NR_ACTIVE_ANON)),
 		       nid, K(node_page_state(pgdat, NR_INACTIVE_ANON)),
 		       nid, K(node_page_state(pgdat, NR_ACTIVE_FILE)),
diff --git a/drivers/base/power/sysfs.c b/drivers/base/power/sysfs.c
index 61e16786f6c5..e05207abb99e 100644
--- a/drivers/base/power/sysfs.c
+++ b/drivers/base/power/sysfs.c
@@ -102,7 +102,7 @@ static ssize_t control_show(struct device *dev, struct device_attribute *attr,
 			    char *buf)
 {
 	return sysfs_emit(buf, "%s\n",
-				dev->power.runtime_auto ? ctrl_auto : ctrl_on);
+			  dev->power.runtime_auto ? ctrl_auto : ctrl_on);
 }

 static ssize_t control_store(struct device * dev, struct device_attribute *attr,
-- 
2.26.0

^ permalink raw reply related	[flat|nested] 5+ messages in thread

* [PATCH V3 5/8] drivers core: Miscellaneous changes for sysfs_emit
  2020-09-16 20:40 [PATCH V3 0/8] sysfs: drivers core: Add and use sysfs_emit and sysfs_emit_at Joe Perches
                   ` (2 preceding siblings ...)
  2020-09-16 20:40 ` [PATCH V3 4/8] drivers core: Reindent a couple uses around sysfs_emit Joe Perches
@ 2020-09-16 20:40 ` Joe Perches
  3 siblings, 0 replies; 5+ messages in thread
From: Joe Perches @ 2020-09-16 20:40 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Rafael J . Wysocki, Johannes Berg,
	Luis Chamberlain, Pavel Machek, Len Brown
  Cc: Denis Efremov, Julia Lawall, Alex Dewar, linux-kernel, linux-pm

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: Joe Perches <joe@perches.com>
---
 drivers/base/bus.c                      |   2 +-
 drivers/base/cacheinfo.c                |   2 +-
 drivers/base/class.c                    |   2 +-
 drivers/base/core.c                     |  34 +--
 drivers/base/cpu.c                      |  62 +++---
 drivers/base/dd.c                       |   1 +
 drivers/base/devcoredump.c              |   2 +-
 drivers/base/firmware_loader/fallback.c |   2 +-
 drivers/base/memory.c                   |   5 +-
 drivers/base/node.c                     | 268 ++++++++++++------------
 drivers/base/platform.c                 |  13 +-
 drivers/base/power/sysfs.c              | 103 +++++----
 drivers/base/power/wakeup_stats.c       |   5 +-
 drivers/base/soc.c                      |  64 +++---
 drivers/base/topology.c                 |  10 +-
 15 files changed, 308 insertions(+), 267 deletions(-)

diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index 886e9054999a..a9c23ecebc7c 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -229,7 +229,7 @@ static DRIVER_ATTR_IGNORE_LOCKDEP(bind, S_IWUSR, NULL, bind_store);
 
 static ssize_t drivers_autoprobe_show(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 drivers_autoprobe_store(struct bus_type *bus,
diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c
index 96f8af414a48..4946647bd985 100644
--- a/drivers/base/cacheinfo.c
+++ b/drivers/base/cacheinfo.c
@@ -362,7 +362,7 @@ 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);
diff --git a/drivers/base/class.c b/drivers/base/class.c
index bcd410e6d70a..c3451481194e 100644
--- a/drivers/base/class.c
+++ b/drivers/base/class.c
@@ -478,7 +478,7 @@ 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);
diff --git a/drivers/base/core.c b/drivers/base/core.c
index c5d2cc8bb8b0..3a0701261ff2 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -239,27 +239,35 @@ void device_pm_move_to_tail(struct device *dev)
 #define to_devlink(dev)	container_of((dev), struct device_link, link_dev)
 
 static ssize_t status_show(struct device *dev,
-			  struct device_attribute *attr, char *buf)
+			   struct device_attribute *attr, char *buf)
 {
-	char *status;
+	const char *output;
 
 	switch (to_devlink(dev)->status) {
 	case DL_STATE_NONE:
-		status = "not tracked"; break;
+		output = "not tracked";
+		break;
 	case DL_STATE_DORMANT:
-		status = "dormant"; break;
+		output = "dormant";
+		break;
 	case DL_STATE_AVAILABLE:
-		status = "available"; break;
+		output = "available";
+		break;
 	case DL_STATE_CONSUMER_PROBE:
-		status = "consumer probing"; break;
+		output = "consumer probing";
+		break;
 	case DL_STATE_ACTIVE:
-		status = "active"; break;
+		output = "active";
+		break;
 	case DL_STATE_SUPPLIER_UNBIND:
-		status = "supplier unbinding"; break;
+		output = "supplier unbinding";
+		break;
 	default:
-		status = "unknown"; break;
+		output = "unknown";
+		break;
 	}
-	return sysfs_emit(buf, "%s\n", status);
+
+	return sysfs_emit(buf, "%s\n", output);
 }
 static DEVICE_ATTR_RO(status);
 
@@ -1933,7 +1941,7 @@ 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 */
@@ -1963,10 +1971,10 @@ 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,
diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index 232f8146a8c4..8f1d6569564c 100644
--- a/drivers/base/cpu.c
+++ b/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_ADMIN_RO(crash_notes);
 
-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_ADMIN_RO(crash_notes_size);
 
 static struct attribute *crash_note_cpu_attrs[] = {
 	&dev_attr_crash_notes.attr,
@@ -241,37 +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 += scnprintf(&buf[n], len - n, "%u", nr_cpu_ids);
+			len += sysfs_emit_at(buf, len, "%u", nr_cpu_ids);
 		else
-			n += scnprintf(&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 += scnprintf(&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;
+	int len;
 	cpumask_var_t isolated;
 
 	if (!alloc_cpumask_var(&isolated, GFP_KERNEL))
@@ -279,17 +276,17 @@ static ssize_t print_cpus_isolated(struct device *dev,
 
 	cpumask_andnot(isolated, cpu_possible_mask,
 		       housekeeping_cpumask(HK_FLAG_DOMAIN));
-	n = sysfs_emit(buf, "%*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);
 
 #ifdef CONFIG_NO_HZ_FULL
 static ssize_t print_cpus_nohz_full(struct device *dev,
-				  struct device_attribute *attr, char *buf)
+				    struct device_attribute *attr, char *buf)
 {
 	return sysfs_emit(buf, "%*pbl\n", cpumask_pr_args(tick_nohz_full_mask));
 }
@@ -320,22 +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)
@@ -557,7 +555,7 @@ 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");
 }
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 123a1c3e9f18..b52d69eb4e71 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -486,6 +486,7 @@ static ssize_t state_synced_show(struct device *dev,
 	device_lock(dev);
 	val = dev->state_synced;
 	device_unlock(dev);
+
 	return sysfs_emit(buf, "%u\n", val);
 }
 static DEVICE_ATTR_RO(state_synced);
diff --git a/drivers/base/devcoredump.c b/drivers/base/devcoredump.c
index e42d0b514384..9243468e2c99 100644
--- a/drivers/base/devcoredump.c
+++ b/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,
diff --git a/drivers/base/firmware_loader/fallback.c b/drivers/base/firmware_loader/fallback.c
index 7e9598a1577a..d60e6d8c967c 100644
--- a/drivers/base/firmware_loader/fallback.c
+++ b/drivers/base/firmware_loader/fallback.c
@@ -124,7 +124,7 @@ 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());
 }
 
 /**
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 7abf9eb8bff0..eef4ffb6122c 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -119,6 +119,7 @@ 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);
 }
 
@@ -301,6 +302,7 @@ 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);
 }
 
@@ -314,6 +316,7 @@ 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);
 }
 
@@ -354,7 +357,7 @@ 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);
diff --git a/drivers/base/node.c b/drivers/base/node.c
index b2dcca375da6..b33526a9fcfc 100644
--- a/drivers/base/node.c
+++ b/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
@@ -153,13 +157,14 @@ 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)
@@ -225,7 +230,8 @@ 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);
 
@@ -361,7 +367,7 @@ 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;
@@ -370,112 +376,112 @@ static ssize_t node_read_meminfo(struct device *dev,
 	si_meminfo_node(&i, nid);
 	sreclaimable = node_page_state_pages(pgdat, NR_SLAB_RECLAIMABLE_B);
 	sunreclaimable = node_page_state_pages(pgdat, NR_SLAB_UNRECLAIMABLE_B);
-	n = sysfs_emit(buf,
-		       "Node %d MemTotal:       %8lu kB\n"
-		       "Node %d MemFree:        %8lu kB\n"
-		       "Node %d MemUsed:        %8lu kB\n"
-		       "Node %d Active:         %8lu kB\n"
-		       "Node %d Inactive:       %8lu kB\n"
-		       "Node %d Active(anon):   %8lu kB\n"
-		       "Node %d Inactive(anon): %8lu kB\n"
-		       "Node %d Active(file):   %8lu kB\n"
-		       "Node %d Inactive(file): %8lu kB\n"
-		       "Node %d Unevictable:    %8lu kB\n"
-		       "Node %d Mlocked:        %8lu kB\n",
-		       nid, K(i.totalram),
-		       nid, K(i.freeram),
-		       nid, K(i.totalram - i.freeram),
-		       nid, K(node_page_state(pgdat, NR_ACTIVE_ANON) +
-			      node_page_state(pgdat, NR_ACTIVE_FILE)),
-		       nid, K(node_page_state(pgdat, NR_INACTIVE_ANON) +
-			      node_page_state(pgdat, NR_INACTIVE_FILE)),
-		       nid, K(node_page_state(pgdat, NR_ACTIVE_ANON)),
-		       nid, K(node_page_state(pgdat, NR_INACTIVE_ANON)),
-		       nid, K(node_page_state(pgdat, NR_ACTIVE_FILE)),
-		       nid, K(node_page_state(pgdat, NR_INACTIVE_FILE)),
-		       nid, K(node_page_state(pgdat, NR_UNEVICTABLE)),
-		       nid, K(sum_zone_node_page_state(nid, NR_MLOCK)));
+	len = sysfs_emit_at(buf, len,
+			    "Node %d MemTotal:       %8lu kB\n"
+			    "Node %d MemFree:        %8lu kB\n"
+			    "Node %d MemUsed:        %8lu kB\n"
+			    "Node %d Active:         %8lu kB\n"
+			    "Node %d Inactive:       %8lu kB\n"
+			    "Node %d Active(anon):   %8lu kB\n"
+			    "Node %d Inactive(anon): %8lu kB\n"
+			    "Node %d Active(file):   %8lu kB\n"
+			    "Node %d Inactive(file): %8lu kB\n"
+			    "Node %d Unevictable:    %8lu kB\n"
+			    "Node %d Mlocked:        %8lu kB\n",
+			    nid, K(i.totalram),
+			    nid, K(i.freeram),
+			    nid, K(i.totalram - i.freeram),
+			    nid, K(node_page_state(pgdat, NR_ACTIVE_ANON) +
+				   node_page_state(pgdat, NR_ACTIVE_FILE)),
+			    nid, K(node_page_state(pgdat, NR_INACTIVE_ANON) +
+				   node_page_state(pgdat, NR_INACTIVE_FILE)),
+			    nid, K(node_page_state(pgdat, NR_ACTIVE_ANON)),
+			    nid, K(node_page_state(pgdat, NR_INACTIVE_ANON)),
+			    nid, K(node_page_state(pgdat, NR_ACTIVE_FILE)),
+			    nid, K(node_page_state(pgdat, NR_INACTIVE_FILE)),
+			    nid, K(node_page_state(pgdat, NR_UNEVICTABLE)),
+			    nid, K(sum_zone_node_page_state(nid, NR_MLOCK)));
 
 #ifdef CONFIG_HIGHMEM
-	n += sprintf(buf + n,
-		       "Node %d HighTotal:      %8lu kB\n"
-		       "Node %d HighFree:       %8lu kB\n"
-		       "Node %d LowTotal:       %8lu kB\n"
-		       "Node %d LowFree:        %8lu kB\n",
-		       nid, K(i.totalhigh),
-		       nid, K(i.freehigh),
-		       nid, K(i.totalram - i.totalhigh),
-		       nid, K(i.freeram - i.freehigh));
+	len += sysfs_emit_at(buf, len,
+			     "Node %d HighTotal:      %8lu kB\n"
+			     "Node %d HighFree:       %8lu kB\n"
+			     "Node %d LowTotal:       %8lu kB\n"
+			     "Node %d LowFree:        %8lu kB\n",
+			     nid, K(i.totalhigh),
+			     nid, K(i.freehigh),
+			     nid, K(i.totalram - i.totalhigh),
+			     nid, K(i.freeram - i.freehigh));
 #endif
-	n += sprintf(buf + n,
-		       "Node %d Dirty:          %8lu kB\n"
-		       "Node %d Writeback:      %8lu kB\n"
-		       "Node %d FilePages:      %8lu kB\n"
-		       "Node %d Mapped:         %8lu kB\n"
-		       "Node %d AnonPages:      %8lu kB\n"
-		       "Node %d Shmem:          %8lu kB\n"
-		       "Node %d KernelStack:    %8lu kB\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"
+			     "Node %d Mapped:         %8lu kB\n"
+			     "Node %d AnonPages:      %8lu kB\n"
+			     "Node %d Shmem:          %8lu kB\n"
+			     "Node %d KernelStack:    %8lu kB\n"
 #ifdef CONFIG_SHADOW_CALL_STACK
-		       "Node %d ShadowCallStack:%8lu kB\n"
+			     "Node %d ShadowCallStack:%8lu kB\n"
 #endif
-		       "Node %d PageTables:     %8lu kB\n"
-		       "Node %d NFS_Unstable:   %8lu kB\n"
-		       "Node %d Bounce:         %8lu kB\n"
-		       "Node %d WritebackTmp:   %8lu kB\n"
-		       "Node %d KReclaimable:   %8lu kB\n"
-		       "Node %d Slab:           %8lu kB\n"
-		       "Node %d SReclaimable:   %8lu kB\n"
-		       "Node %d SUnreclaim:     %8lu kB\n"
+			     "Node %d PageTables:     %8lu kB\n"
+			     "Node %d NFS_Unstable:   %8lu kB\n"
+			     "Node %d Bounce:         %8lu kB\n"
+			     "Node %d WritebackTmp:   %8lu kB\n"
+			     "Node %d KReclaimable:   %8lu kB\n"
+			     "Node %d Slab:           %8lu kB\n"
+			     "Node %d SReclaimable:   %8lu kB\n"
+			     "Node %d SUnreclaim:     %8lu kB\n"
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
-		       "Node %d AnonHugePages:  %8lu kB\n"
-		       "Node %d ShmemHugePages: %8lu kB\n"
-		       "Node %d ShmemPmdMapped: %8lu kB\n"
-		       "Node %d FileHugePages: %8lu kB\n"
-		       "Node %d FilePmdMapped: %8lu kB\n"
+			     "Node %d AnonHugePages:  %8lu kB\n"
+			     "Node %d ShmemHugePages: %8lu kB\n"
+			     "Node %d ShmemPmdMapped: %8lu kB\n"
+			     "Node %d FileHugePages: %8lu kB\n"
+			     "Node %d FilePmdMapped: %8lu kB\n"
 #endif
-			,
-		       nid, K(node_page_state(pgdat, NR_FILE_DIRTY)),
-		       nid, K(node_page_state(pgdat, NR_WRITEBACK)),
-		       nid, K(node_page_state(pgdat, NR_FILE_PAGES)),
-		       nid, K(node_page_state(pgdat, NR_FILE_MAPPED)),
-		       nid, K(node_page_state(pgdat, NR_ANON_MAPPED)),
-		       nid, K(i.sharedram),
-		       nid, node_page_state(pgdat, NR_KERNEL_STACK_KB),
+			     ,
+			     nid, K(node_page_state(pgdat, NR_FILE_DIRTY)),
+			     nid, K(node_page_state(pgdat, NR_WRITEBACK)),
+			     nid, K(node_page_state(pgdat, NR_FILE_PAGES)),
+			     nid, K(node_page_state(pgdat, NR_FILE_MAPPED)),
+			     nid, K(node_page_state(pgdat, NR_ANON_MAPPED)),
+			     nid, K(i.sharedram),
+			     nid, node_page_state(pgdat, NR_KERNEL_STACK_KB),
 #ifdef CONFIG_SHADOW_CALL_STACK
-		       nid, node_page_state(pgdat, NR_KERNEL_SCS_KB),
+			     nid, node_page_state(pgdat, NR_KERNEL_SCS_KB),
 #endif
-		       nid, K(sum_zone_node_page_state(nid, NR_PAGETABLE)),
-		       nid, 0UL,
-		       nid, K(sum_zone_node_page_state(nid, NR_BOUNCE)),
-		       nid, K(node_page_state(pgdat, NR_WRITEBACK_TEMP)),
-		       nid, K(sreclaimable +
-			      node_page_state(pgdat, NR_KERNEL_MISC_RECLAIMABLE)),
-		       nid, K(sreclaimable + sunreclaimable),
-		       nid, K(sreclaimable),
-		       nid, K(sunreclaimable)
+			     nid, K(sum_zone_node_page_state(nid, NR_PAGETABLE)),
+			     nid, 0UL,
+			     nid, K(sum_zone_node_page_state(nid, NR_BOUNCE)),
+			     nid, K(node_page_state(pgdat, NR_WRITEBACK_TEMP)),
+			     nid, K(sreclaimable +
+				    node_page_state(pgdat, NR_KERNEL_MISC_RECLAIMABLE)),
+			     nid, K(sreclaimable + sunreclaimable),
+			     nid, K(sreclaimable),
+			     nid, K(sunreclaimable)
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
-		       ,
-		       nid, K(node_page_state(pgdat, NR_ANON_THPS) *
-				       HPAGE_PMD_NR),
-		       nid, K(node_page_state(pgdat, NR_SHMEM_THPS) *
-				       HPAGE_PMD_NR),
-		       nid, K(node_page_state(pgdat, NR_SHMEM_PMDMAPPED) *
-				       HPAGE_PMD_NR),
-		       nid, K(node_page_state(pgdat, NR_FILE_THPS) *
-				       HPAGE_PMD_NR),
-		       nid, K(node_page_state(pgdat, NR_FILE_PMDMAPPED) *
-				       HPAGE_PMD_NR)
+			     ,
+			     nid, K(node_page_state(pgdat, NR_ANON_THPS) *
+				    HPAGE_PMD_NR),
+			     nid, K(node_page_state(pgdat, NR_SHMEM_THPS) *
+				    HPAGE_PMD_NR),
+			     nid, K(node_page_state(pgdat, NR_SHMEM_PMDMAPPED) *
+				    HPAGE_PMD_NR),
+			     nid, K(node_page_state(pgdat, NR_FILE_THPS) *
+				    HPAGE_PMD_NR),
+			     nid, K(node_page_state(pgdat, NR_FILE_PMDMAPPED) *
+				    HPAGE_PMD_NR)
 #endif
-		       );
-	n += hugetlb_report_node_meminfo(nid, buf + n);
-	return n;
+			    );
+	len += hugetlb_report_node_meminfo(nid, buf + len);
+	return len;
 }
 
 #undef K
-static DEVICE_ATTR(meminfo, S_IRUGO, node_read_meminfo, NULL);
+static DEVICE_ATTR(meminfo, 0444, node_read_meminfo, NULL);
 
 static ssize_t node_read_numastat(struct device *dev,
-				struct device_attribute *attr, char *buf)
+				  struct device_attribute *attr, char *buf)
 {
 	return sysfs_emit(buf,
 			  "numa_hit %lu\n"
@@ -491,7 +497,7 @@ 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)
@@ -499,28 +505,31 @@ 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", zone_stat_name(i),
-			     sum_zone_node_page_state(nid, i));
+		len += sysfs_emit_at(buf, len, "%s %lu\n",
+				     zone_stat_name(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", numa_stat_name(i),
-			     sum_zone_numa_state(nid, i));
-#endif
+		len += sysfs_emit_at(buf, len, "%s %lu\n",
+				     numa_stat_name(i),
+				     sum_zone_numa_state(nid, i));
 
+#endif
 	for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++)
-		n += sprintf(buf+n, "%s %lu\n", node_stat_name(i),
-			     node_page_state_pages(pgdat, i));
+		len += sysfs_emit_at(buf, len, "%s %lu\n",
+				     node_stat_name(i),
+				     node_page_state_pages(pgdat, i));
 
-	return n;
+	return len;
 }
-static DEVICE_ATTR(vmstat, S_IRUGO, node_read_vmstat, NULL);
+static DEVICE_ATTR(vmstat, 0444, node_read_vmstat, NULL);
 
 static ssize_t node_read_distance(struct device *dev,
-			struct device_attribute *attr, char *buf)
+				  struct device_attribute *attr, char *buf)
 {
 	int nid = dev->id;
 	int len = 0;
@@ -532,13 +541,15 @@ 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,
@@ -979,17 +990,6 @@ 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;
@@ -999,7 +999,9 @@ 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) \
diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index f0f8cfcc3621..88aef93eb4dd 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -1023,10 +1023,10 @@ 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);
@@ -1037,9 +1037,7 @@ 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);
 
@@ -1086,12 +1084,13 @@ static ssize_t driver_override_show(struct device *dev,
 	device_lock(dev);
 	len = sysfs_emit(buf, "%s\n", pdev->driver_override);
 	device_unlock(dev);
+
 	return len;
 }
 static DEVICE_ATTR_RW(driver_override);
 
 static ssize_t numa_node_show(struct device *dev,
-		struct device_attribute *attr, char *buf)
+			      struct device_attribute *attr, char *buf)
 {
 	return sysfs_emit(buf, "%d\n", dev_to_node(dev));
 }
diff --git a/drivers/base/power/sysfs.c b/drivers/base/power/sysfs.c
index e05207abb99e..a1474fb67db9 100644
--- a/drivers/base/power/sysfs.c
+++ b/drivers/base/power/sysfs.c
@@ -122,66 +122,70 @@ static ssize_t control_store(struct device * dev, struct device_attribute *attr,
 static DEVICE_ATTR_RW(control);
 
 static ssize_t runtime_active_time_show(struct device *dev,
-				struct device_attribute *attr, char *buf)
+					struct device_attribute *attr,
+					char *buf)
 {
-	int ret;
 	u64 tmp = pm_runtime_active_time(dev);
+
 	do_div(tmp, NSEC_PER_MSEC);
-	ret = sysfs_emit(buf, "%llu\n", tmp);
-	return ret;
+
+	return sysfs_emit(buf, "%llu\n", tmp);
 }
 
 static DEVICE_ATTR_RO(runtime_active_time);
 
 static ssize_t runtime_suspended_time_show(struct device *dev,
-				struct device_attribute *attr, char *buf)
+					   struct device_attribute *attr,
+					   char *buf)
 {
-	int ret;
 	u64 tmp = pm_runtime_suspended_time(dev);
+
 	do_div(tmp, NSEC_PER_MSEC);
-	ret = sysfs_emit(buf, "%llu\n", tmp);
-	return ret;
+
+	return sysfs_emit(buf, "%llu\n", tmp);
 }
 
 static DEVICE_ATTR_RO(runtime_suspended_time);
 
 static ssize_t runtime_status_show(struct device *dev,
-				struct device_attribute *attr, char *buf)
+				   struct device_attribute *attr, char *buf)
 {
-	const char *p;
+	const char *output;
 
 	if (dev->power.runtime_error) {
-		p = "error\n";
+		output = "error";
 	} else if (dev->power.disable_depth) {
-		p = "unsupported\n";
+		output = "unsupported";
 	} else {
 		switch (dev->power.runtime_status) {
 		case RPM_SUSPENDED:
-			p = "suspended\n";
+			output = "suspended";
 			break;
 		case RPM_SUSPENDING:
-			p = "suspending\n";
+			output = "suspending";
 			break;
 		case RPM_RESUMING:
-			p = "resuming\n";
+			output = "resuming";
 			break;
 		case RPM_ACTIVE:
-			p = "active\n";
+			output = "active";
 			break;
 		default:
 			return -EIO;
 		}
 	}
-	return sysfs_emit(buf, p);
+	return sysfs_emit(buf, "%s\n", output);
 }
 
 static DEVICE_ATTR_RO(runtime_status);
 
 static ssize_t autosuspend_delay_ms_show(struct device *dev,
-		struct device_attribute *attr, char *buf)
+					 struct device_attribute *attr,
+					 char *buf)
 {
 	if (!dev->power.use_autosuspend)
 		return -EIO;
+
 	return sysfs_emit(buf, "%d\n", dev->power.autosuspend_delay);
 }
 
@@ -345,7 +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);
@@ -354,7 +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);
@@ -363,7 +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);
@@ -372,7 +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);
@@ -381,7 +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);
@@ -390,7 +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);
@@ -399,7 +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);
@@ -408,7 +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);
@@ -416,7 +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);
@@ -425,7 +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);
@@ -434,7 +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);
@@ -443,7 +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);
@@ -451,7 +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);
@@ -460,7 +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);
@@ -469,7 +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);
@@ -478,7 +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 inline int dpm_sysfs_wakeup_change_owner(struct device *dev, kuid_t kuid,
@@ -496,7 +524,7 @@ 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);
@@ -505,7 +533,10 @@ 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);
diff --git a/drivers/base/power/wakeup_stats.c b/drivers/base/power/wakeup_stats.c
index 5568e25d7c9c..d638259b829a 100644
--- a/drivers/base/power/wakeup_stats.c
+++ b/drivers/base/power/wakeup_stats.c
@@ -26,7 +26,7 @@ static ssize_t _name##_show(struct device *dev,				\
 {									\
 	struct wakeup_source *ws = dev_get_drvdata(dev);		\
 									\
-	return sprintf(buf, "%lu\n", ws->_name);			\
+	return sysfs_emit(buf, "%lu\n", ws->_name);			\
 }									\
 static DEVICE_ATTR_RO(_name)
 
@@ -57,6 +57,7 @@ static ssize_t total_time_ms_show(struct device *dev,
 		active_time = ktime_sub(ktime_get(), ws->last_time);
 		total_time = ktime_add(total_time, active_time);
 	}
+
 	return sysfs_emit(buf, "%lld\n", ktime_to_ms(total_time));
 }
 static DEVICE_ATTR_RO(total_time_ms);
@@ -73,6 +74,7 @@ static ssize_t max_time_ms_show(struct device *dev,
 		if (active_time > max_time)
 			max_time = active_time;
 	}
+
 	return sysfs_emit(buf, "%lld\n", ktime_to_ms(max_time));
 }
 static DEVICE_ATTR_RO(max_time_ms);
@@ -106,6 +108,7 @@ static ssize_t prevent_suspend_time_ms_show(struct device *dev,
 		prevent_sleep_time = ktime_add(prevent_sleep_time,
 			ktime_sub(ktime_get(), ws->start_prevent_time));
 	}
+
 	return sysfs_emit(buf, "%lld\n", ktime_to_ms(prevent_sleep_time));
 }
 static DEVICE_ATTR_RO(prevent_suspend_time_ms);
diff --git a/drivers/base/soc.c b/drivers/base/soc.c
index fc6536a7eac6..d34609bb7386 100644
--- a/drivers/base/soc.c
+++ b/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;
@@ -31,11 +31,11 @@ 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(serial_number, 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(serial_number,	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)
 {
@@ -49,45 +49,41 @@ static umode_t soc_attribute_mode(struct kobject *kobj,
 	struct device *dev = kobj_to_dev(kobj);
 	struct soc_device *soc_dev = container_of(dev, struct soc_device, dev);
 
-	if ((attr == &dev_attr_machine.attr)
-	    && (soc_dev->attr->machine != NULL))
+	if ((attr == &dev_attr_machine.attr) && soc_dev->attr->machine)
 		return attr->mode;
-	if ((attr == &dev_attr_family.attr)
-	    && (soc_dev->attr->family != NULL))
+	if ((attr == &dev_attr_family.attr) && soc_dev->attr->family)
 		return attr->mode;
-	if ((attr == &dev_attr_revision.attr)
-	    && (soc_dev->attr->revision != NULL))
+	if ((attr == &dev_attr_revision.attr) && soc_dev->attr->revision)
 		return attr->mode;
-	if ((attr == &dev_attr_serial_number.attr)
-	    && (soc_dev->attr->serial_number != NULL))
+	if ((attr == &dev_attr_serial_number.attr) && soc_dev->attr->serial_number)
 		return attr->mode;
-	if ((attr == &dev_attr_soc_id.attr)
-	    && (soc_dev->attr->soc_id != NULL))
+	if ((attr == &dev_attr_soc_id.attr) && soc_dev->attr->soc_id)
 		return attr->mode;
 
-	/* Unknown or unfilled attribute. */
+	/* Unknown or unfilled attribute */
 	return 0;
 }
 
-static ssize_t soc_info_get(struct device *dev,
-			    struct device_attribute *attr,
-			    char *buf)
+static ssize_t soc_info_show(struct device *dev, struct device_attribute *attr,
+			     char *buf)
 {
 	struct soc_device *soc_dev = container_of(dev, struct soc_device, dev);
+	const char *output;
 
 	if (attr == &dev_attr_machine)
-		return sysfs_emit(buf, "%s\n", soc_dev->attr->machine);
-	if (attr == &dev_attr_family)
-		return sysfs_emit(buf, "%s\n", soc_dev->attr->family);
-	if (attr == &dev_attr_revision)
-		return sysfs_emit(buf, "%s\n", soc_dev->attr->revision);
-	if (attr == &dev_attr_serial_number)
-		return sysfs_emit(buf, "%s\n", soc_dev->attr->serial_number);
-	if (attr == &dev_attr_soc_id)
-		return sysfs_emit(buf, "%s\n", soc_dev->attr->soc_id);
-
-	return -EINVAL;
-
+		output = soc_dev->attr->machine;
+	else if (attr == &dev_attr_family)
+		output = soc_dev->attr->family;
+	else if (attr == &dev_attr_revision)
+		output = soc_dev->attr->revision;
+	else if (attr == &dev_attr_serial_number)
+		output = soc_dev->attr->serial_number;
+	else if (attr == &dev_attr_soc_id)
+		output = soc_dev->attr->soc_id;
+	else
+		return -EINVAL;
+
+	return sysfs_emit(buf, "%s\n", output);
 }
 
 static struct attribute *soc_attr[] = {
diff --git a/drivers/base/topology.c b/drivers/base/topology.c
index ad8d33c6077b..4d254fcc93d1 100644
--- a/drivers/base/topology.c
+++ b/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)				\
-- 
2.26.0


^ permalink raw reply related	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2020-09-16 20:42 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-09-16 20:40 [PATCH V3 0/8] sysfs: drivers core: Add and use sysfs_emit and sysfs_emit_at Joe Perches
2020-09-16 20:40 ` [PATCH V3 2/8] drivers core: Use sysfs_emit and sysfs_emit_at for show(device *...) functions Joe Perches
2020-09-16 20:40 ` [PATCH V3 3/8] drivers core: Remove strcat uses around sysfs_emit and neaten Joe Perches
2020-09-16 20:40 ` [PATCH V3 4/8] drivers core: Reindent a couple uses around sysfs_emit Joe Perches
2020-09-16 20:40 ` [PATCH V3 5/8] drivers core: Miscellaneous changes for sysfs_emit Joe Perches

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