cpuidle: sysfs: Use sysfs_emit()/sysfs_emit_at() instead of sprintf()/scnprintf()

The ->show() callbacks in sysfs should use sysfs_emit() or
sysfs_emit_at() when formatting values for user space.

These helpers are the recommended way to ensure correct buffer
handling and consistency across the kernel.

See Documentation/filesystems/sysfs.rst for details.

No functional change intended.

Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Vivek Yadav <vivekyadav1207731111@gmail.com>
Link: https://patch.msgid.link/20250919165657.233349-1-vivekyadav1207731111@gmail.com
[ rjw: Minor subject edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/cpuidle/sysfs.c b/drivers/cpuidle/sysfs.c
index d6f5da61cb7d86b1cd5423aa96b9d1e9285d66f7..61de6481760471dd22462dc917e7fa554ca95792 100644 (file)
--- a/drivers/cpuidle/sysfs.c
+++ b/drivers/cpuidle/sysfs.c
@@ -27,14 +27,14 @@ static ssize_t show_available_governors(struct device *dev,
 
        mutex_lock(&cpuidle_lock);
        list_for_each_entry(tmp, &cpuidle_governors, governor_list) {
-               if (i >= (ssize_t) (PAGE_SIZE - (CPUIDLE_NAME_LEN + 2)))
+               if (i >= (ssize_t)(PAGE_SIZE - (CPUIDLE_NAME_LEN + 2)))
                        goto out;
 
-               i += scnprintf(&buf[i], CPUIDLE_NAME_LEN + 1, "%s ", tmp->name);
+               i += sysfs_emit_at(buf, i, "%.*s ", CPUIDLE_NAME_LEN, tmp->name);
        }
 
 out:
-       i+= sprintf(&buf[i], "\n");
+       i += sysfs_emit_at(buf, i, "\n");
        mutex_unlock(&cpuidle_lock);
        return i;
 }
@@ -49,9 +49,9 @@ static ssize_t show_current_driver(struct device *dev,
        spin_lock(&cpuidle_driver_lock);
        drv = cpuidle_get_driver();
        if (drv)
-               ret = sprintf(buf, "%s\n", drv->name);
+               ret = sysfs_emit(buf, "%s\n", drv->name);
        else
-               ret = sprintf(buf, "none\n");
+               ret = sysfs_emit(buf, "none\n");
        spin_unlock(&cpuidle_driver_lock);
 
        return ret;
@@ -65,9 +65,9 @@ static ssize_t show_current_governor(struct device *dev,
 
        mutex_lock(&cpuidle_lock);
        if (cpuidle_curr_governor)
-               ret = sprintf(buf, "%s\n", cpuidle_curr_governor->name);
+               ret = sysfs_emit(buf, "%s\n", cpuidle_curr_governor->name);
        else
-               ret = sprintf(buf, "none\n");
+               ret = sysfs_emit(buf, "none\n");
        mutex_unlock(&cpuidle_lock);
 
        return ret;
@@ -230,7 +230,7 @@ static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0644, show, store)
 static ssize_t show_state_##_name(struct cpuidle_state *state, \
                         struct cpuidle_state_usage *state_usage, char *buf) \
 { \
-       return sprintf(buf, "%u\n", state->_name);\
+       return sysfs_emit(buf, "%u\n", state->_name);\
 }
 
 #define define_show_state_ull_function(_name) \
@@ -238,7 +238,7 @@ static ssize_t show_state_##_name(struct cpuidle_state *state, \
                                  struct cpuidle_state_usage *state_usage, \
                                  char *buf)                            \
 { \
-       return sprintf(buf, "%llu\n", state_usage->_name);\
+       return sysfs_emit(buf, "%llu\n", state_usage->_name);\
 }
 
 #define define_show_state_str_function(_name) \
@@ -247,8 +247,8 @@ static ssize_t show_state_##_name(struct cpuidle_state *state, \
                                  char *buf)                            \
 { \
        if (state->_name[0] == '\0')\
-               return sprintf(buf, "<null>\n");\
-       return sprintf(buf, "%s\n", state->_name);\
+               return sysfs_emit(buf, "<null>\n");\
+       return sysfs_emit(buf, "%s\n", state->_name);\
 }
 
 #define define_show_state_time_function(_name) \
@@ -256,7 +256,7 @@ static ssize_t show_state_##_name(struct cpuidle_state *state, \
                                  struct cpuidle_state_usage *state_usage, \
                                  char *buf) \
 { \
-       return sprintf(buf, "%llu\n", ktime_to_us(state->_name##_ns)); \
+       return sysfs_emit(buf, "%llu\n", ktime_to_us(state->_name##_ns)); \
 }
 
 define_show_state_time_function(exit_latency)
@@ -273,14 +273,14 @@ static ssize_t show_state_time(struct cpuidle_state *state,
                               struct cpuidle_state_usage *state_usage,
                               char *buf)
 {
-       return sprintf(buf, "%llu\n", ktime_to_us(state_usage->time_ns));
+       return sysfs_emit(buf, "%llu\n", ktime_to_us(state_usage->time_ns));
 }
 
 static ssize_t show_state_disable(struct cpuidle_state *state,
                                  struct cpuidle_state_usage *state_usage,
                                  char *buf)
 {
-       return sprintf(buf, "%llu\n",
+       return sysfs_emit(buf, "%llu\n",
                       state_usage->disable & CPUIDLE_STATE_DISABLED_BY_USER);
 }
 
@@ -310,7 +310,7 @@ static ssize_t show_state_default_status(struct cpuidle_state *state,
                                          struct cpuidle_state_usage *state_usage,
                                          char *buf)
 {
-       return sprintf(buf, "%s\n",
+       return sysfs_emit(buf, "%s\n",
                       state->flags & CPUIDLE_FLAG_OFF ? "disabled" : "enabled");
 }
 
@@ -358,7 +358,7 @@ static ssize_t show_state_s2idle_##_name(struct cpuidle_state *state, \
                                         struct cpuidle_state_usage *state_usage, \
                                         char *buf)                             \
 { \
-       return sprintf(buf, "%llu\n", state_usage->s2idle_##_name);\
+       return sysfs_emit(buf, "%llu\n", state_usage->s2idle_##_name);\
 }
 
 define_show_state_s2idle_ull_function(usage);
@@ -550,7 +550,7 @@ static ssize_t show_driver_name(struct cpuidle_driver *drv, char *buf)
        ssize_t ret;
 
        spin_lock(&cpuidle_driver_lock);
-       ret = sprintf(buf, "%s\n", drv ? drv->name : "none");
+       ret = sysfs_emit(buf, "%s\n", drv ? drv->name : "none");
        spin_unlock(&cpuidle_driver_lock);
 
        return ret;