On Thu, 2022-06-30 at 02:50 +0200, Jason A. Donenfeld wrote:
> On Wed, Jun 29, 2022 at 05:36:57PM -0700, Joe Perches wrote:
> > > > +static ssize_t pm_userspace_autosleeper_show(struct kobject *kobj,
> > > > +                               struct kobj_attribute *attr, char *buf)
> > > > +{
> > > > +       return sprintf(buf, "%d\n", pm_userspace_autosleeper_enabled);
> > 
> > This should use sysfs_emit no?
> 
> Probably, yea. Note that I just copy and pasted a nearby function,
> pm_async_show, `:%s/`d the variable name, and then promptly `git diff |
> clip`d it and plonked it into my email. Looking at the file, it uses
> sprintf all over the place in this fashion. So you may want to submit a
> cleanup to Rafael on this if you're right about sysfs_emit() being
> universally preferred.

Perhaps:

(trivial refactored and added a missing newline in autosleep_show)

---
 kernel/power/main.c | 102 ++++++++++++++++++++++++++--------------------------
 1 file changed, 52 insertions(+), 50 deletions(-)

diff --git a/kernel/power/main.c b/kernel/power/main.c
index e3694034b7536..c8a030319b15c 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -100,7 +100,7 @@ int pm_async_enabled = 1;
 static ssize_t pm_async_show(struct kobject *kobj, struct kobj_attribute *attr,
                             char *buf)
 {
-       return sprintf(buf, "%d\n", pm_async_enabled);
+       return sysfs_emit(buf, "%d\n", pm_async_enabled);
 }
 
 static ssize_t pm_async_store(struct kobject *kobj, struct kobj_attribute 
*attr,
@@ -124,27 +124,25 @@ power_attr(pm_async);
 static ssize_t mem_sleep_show(struct kobject *kobj, struct kobj_attribute 
*attr,
                              char *buf)
 {
-       char *s = buf;
+       int len = 0;
        suspend_state_t i;
 
        for (i = PM_SUSPEND_MIN; i < PM_SUSPEND_MAX; i++) {
                if (i >= PM_SUSPEND_MEM && cxl_mem_active())
                        continue;
-               if (mem_sleep_states[i]) {
-                       const char *label = mem_sleep_states[i];
+               if (!mem_sleep_states[i])
+                       continue;
 
-                       if (mem_sleep_current == i)
-                               s += sprintf(s, "[%s] ", label);
-                       else
-                               s += sprintf(s, "%s ", label);
-               }
+               len += sysfs_emit_at(buf, len,
+                                    mem_sleep_current == i ? "[%s] " : "%s ",
+                                    mem_sleep_states[i]);
        }
 
-       /* Convert the last space to a newline if needed. */
-       if (s != buf)
-               *(s-1) = '\n';
+       /* Convert the last space to a newline if needed */
+       if (len)
+               sysfs_emit_at(buf, len - 1, "\n");
 
-       return (s - buf);
+       return len;
 }
 
 static suspend_state_t decode_suspend_state(const char *buf, size_t n)
@@ -205,7 +203,7 @@ bool sync_on_suspend_enabled = 
!IS_ENABLED(CONFIG_SUSPEND_SKIP_SYNC);
 static ssize_t sync_on_suspend_show(struct kobject *kobj,
                                   struct kobj_attribute *attr, char *buf)
 {
-       return sprintf(buf, "%d\n", sync_on_suspend_enabled);
+       return sysfs_emit(buf, "%d\n", sync_on_suspend_enabled);
 }
 
 static ssize_t sync_on_suspend_store(struct kobject *kobj,
@@ -242,22 +240,22 @@ static const char * const pm_tests[__TEST_AFTER_LAST] = {
 static ssize_t pm_test_show(struct kobject *kobj, struct kobj_attribute *attr,
                                char *buf)
 {
-       char *s = buf;
+       int len = 0;
        int level;
 
-       for (level = TEST_FIRST; level <= TEST_MAX; level++)
-               if (pm_tests[level]) {
-                       if (level == pm_test_level)
-                               s += sprintf(s, "[%s] ", pm_tests[level]);
-                       else
-                               s += sprintf(s, "%s ", pm_tests[level]);
-               }
+       for (level = TEST_FIRST; level <= TEST_MAX; level++) {
+               if (!pm_tests[level])
+                       continue;
+               len += sysfs_emit_at(buf, len,
+                                    level == pm_test_level ? "[%s] " : "%s ",
+                                    pm_tests[level]);
+       }
 
-       if (s != buf)
-               /* convert the last space to a newline */
-               *(s-1) = '\n';
+       /* convert the last space to a newline if needed */
+       if (len)
+               sysfs_emit_at(buf, len - 1, "\n");
 
-       return (s - buf);
+       return len;
 }
 
 static ssize_t pm_test_store(struct kobject *kobj, struct kobj_attribute *attr,
@@ -314,7 +312,7 @@ static char *suspend_step_name(enum suspend_stat_step step)
 static ssize_t _name##_show(struct kobject *kobj,              \
                struct kobj_attribute *attr, char *buf)         \
 {                                                              \
-       return sprintf(buf, "%d\n", suspend_stats._name);       \
+       return sysfs_emit(buf, "%d\n", suspend_stats._name);    \
 }                                                              \
 static struct kobj_attribute _name = __ATTR_RO(_name)
 
@@ -339,7 +337,7 @@ static ssize_t last_failed_dev_show(struct kobject *kobj,
        index %= REC_FAILED_NUM;
        last_failed_dev = suspend_stats.failed_devs[index];
 
-       return sprintf(buf, "%s\n", last_failed_dev);
+       return sysfs_emit(buf, "%s\n", last_failed_dev);
 }
 static struct kobj_attribute last_failed_dev = __ATTR_RO(last_failed_dev);
 
@@ -353,7 +351,7 @@ static ssize_t last_failed_errno_show(struct kobject *kobj,
        index %= REC_FAILED_NUM;
        last_failed_errno = suspend_stats.errno[index];
 
-       return sprintf(buf, "%d\n", last_failed_errno);
+       return sysfs_emit(buf, "%d\n", last_failed_errno);
 }
 static struct kobj_attribute last_failed_errno = __ATTR_RO(last_failed_errno);
 
@@ -369,7 +367,7 @@ static ssize_t last_failed_step_show(struct kobject *kobj,
        step = suspend_stats.failed_steps[index];
        last_failed_step = suspend_step_name(step);
 
-       return sprintf(buf, "%s\n", last_failed_step);
+       return sysfs_emit(buf, "%s\n", last_failed_step);
 }
 static struct kobj_attribute last_failed_step = __ATTR_RO(last_failed_step);
 
@@ -477,7 +475,7 @@ bool pm_print_times_enabled;
 static ssize_t pm_print_times_show(struct kobject *kobj,
                                   struct kobj_attribute *attr, char *buf)
 {
-       return sprintf(buf, "%d\n", pm_print_times_enabled);
+       return sysfs_emit(buf, "%d\n", pm_print_times_enabled);
 }
 
 static ssize_t pm_print_times_store(struct kobject *kobj,
@@ -510,7 +508,7 @@ static ssize_t pm_wakeup_irq_show(struct kobject *kobj,
        if (!pm_wakeup_irq())
                return -ENODATA;
 
-       return sprintf(buf, "%u\n", pm_wakeup_irq());
+       return sysfs_emit(buf, "%u\n", pm_wakeup_irq());
 }
 
 power_attr_ro(pm_wakeup_irq);
@@ -520,7 +518,7 @@ bool pm_debug_messages_on __read_mostly;
 static ssize_t pm_debug_messages_show(struct kobject *kobj,
                                      struct kobj_attribute *attr, char *buf)
 {
-       return sprintf(buf, "%d\n", pm_debug_messages_on);
+       return sysfs_emit(buf, "%d\n", pm_debug_messages_on);
 }
 
 static ssize_t pm_debug_messages_store(struct kobject *kobj,
@@ -568,21 +566,24 @@ struct kobject *power_kobj;
 static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
                          char *buf)
 {
-       char *s = buf;
+       int len = 0;
 #ifdef CONFIG_SUSPEND
        suspend_state_t i;
 
-       for (i = PM_SUSPEND_MIN; i < PM_SUSPEND_MAX; i++)
+       for (i = PM_SUSPEND_MIN; i < PM_SUSPEND_MAX; i++) {
                if (pm_states[i])
-                       s += sprintf(s,"%s ", pm_states[i]);
+                       len += sysfs_emit_at(buf, len, "%s ", pm_states[i]);
+       }
 
 #endif
        if (hibernation_available())
-               s += sprintf(s, "disk ");
-       if (s != buf)
-               /* convert the last space to a newline */
-               *(s-1) = '\n';
-       return (s - buf);
+               len += sysfs_emit_at(buf, len, "disk ");
+
+       /* convert the last space to a newline if needed */
+       if (len)
+               sysfs_emit_at(buf, len - 1, "\n");
+
+       return len;
 }
 
 static suspend_state_t decode_state(const char *buf, size_t n)
@@ -681,8 +682,10 @@ static ssize_t wakeup_count_show(struct kobject *kobj,
 {
        unsigned int val;
 
-       return pm_get_wakeup_count(&val, true) ?
-               sprintf(buf, "%u\n", val) : -EINTR;
+       if (!pm_get_wakeup_count(&val, true))
+               return -EINTR;
+
+       return sysfs_emit(buf, "%u\n", val);
 }
 
 static ssize_t wakeup_count_store(struct kobject *kobj,
@@ -724,17 +727,16 @@ static ssize_t autosleep_show(struct kobject *kobj,
        suspend_state_t state = pm_autosleep_state();
 
        if (state == PM_SUSPEND_ON)
-               return sprintf(buf, "off\n");
+               return sysfs_emit(buf, "off\n");
 
 #ifdef CONFIG_SUSPEND
        if (state < PM_SUSPEND_MAX)
-               return sprintf(buf, "%s\n", pm_states[state] ?
-                                       pm_states[state] : "error");
+               return sysfs_emit(buf, "%s\n", pm_states[state] ?: "error");
 #endif
 #ifdef CONFIG_HIBERNATION
-       return sprintf(buf, "disk\n");
+       return sysfs_emit(buf, "disk\n");
 #else
-       return sprintf(buf, "error");
+       return sysfs_emit(buf, "error\n");
 #endif
 }
 
@@ -803,7 +805,7 @@ int pm_trace_enabled;
 static ssize_t pm_trace_show(struct kobject *kobj, struct kobj_attribute *attr,
                             char *buf)
 {
-       return sprintf(buf, "%d\n", pm_trace_enabled);
+       return sysfs_emit(buf, "%d\n", pm_trace_enabled);
 }
 
 static ssize_t
@@ -840,7 +842,7 @@ power_attr_ro(pm_trace_dev_match);
 static ssize_t pm_freeze_timeout_show(struct kobject *kobj,
                                      struct kobj_attribute *attr, char *buf)
 {
-       return sprintf(buf, "%u\n", freeze_timeout_msecs);
+       return sysfs_emit(buf, "%u\n", freeze_timeout_msecs);
 }
 
 static ssize_t pm_freeze_timeout_store(struct kobject *kobj,

Reply via email to