[PATCH] powercap: Replace sprintf() with sysfs_emit() in sysfs show functions
From: Sumeet Pawnikar
Date: Sun Jan 11 2026 - 09:12:51 EST
Replace all sprintf() calls with sysfs_emit() in sysfs show functions.
sysfs_emit() is preferred over sprintf() for formatting sysfs output
as it provides better bounds checking and prevents potential buffer
overflows.
Also, replace sprintf() with sysfs_emit() in show_constraint_name()
and simplify the code by removing the redundant strlen() call since
sysfs_emit() returns the length.
Signed-off-by: Sumeet Pawnikar <sumeet4linux@xxxxxxxxx>
---
drivers/powercap/powercap_sys.c | 13 ++++++-------
1 file changed, 6 insertions(+), 7 deletions(-)
diff --git a/drivers/powercap/powercap_sys.c b/drivers/powercap/powercap_sys.c
index 1ff369880beb..f3b2ae635305 100644
--- a/drivers/powercap/powercap_sys.c
+++ b/drivers/powercap/powercap_sys.c
@@ -27,7 +27,7 @@ static ssize_t _attr##_show(struct device *dev, \
\
if (power_zone->ops->get_##_attr) { \
if (!power_zone->ops->get_##_attr(power_zone, &value)) \
- len = sprintf(buf, "%lld\n", value); \
+ len = sysfs_emit(buf, "%lld\n", value); \
} \
\
return len; \
@@ -75,7 +75,7 @@ static ssize_t show_constraint_##_attr(struct device *dev, \
pconst = &power_zone->constraints[id]; \
if (pconst && pconst->ops && pconst->ops->get_##_attr) { \
if (!pconst->ops->get_##_attr(power_zone, id, &value)) \
- len = sprintf(buf, "%lld\n", value); \
+ len = sysfs_emit(buf, "%lld\n", value); \
} \
\
return len; \
@@ -171,9 +171,8 @@ static ssize_t show_constraint_name(struct device *dev,
if (pconst && pconst->ops && pconst->ops->get_name) {
name = pconst->ops->get_name(power_zone, id);
if (name) {
- sprintf(buf, "%.*s\n", POWERCAP_CONSTRAINT_NAME_LEN - 1,
- name);
- len = strlen(buf);
+ len = sysfs_emit(buf, "%.*s\n",
+ POWERCAP_CONSTRAINT_NAME_LEN - 1, name);
}
}
@@ -350,7 +349,7 @@ static ssize_t name_show(struct device *dev,
{
struct powercap_zone *power_zone = to_powercap_zone(dev);
- return sprintf(buf, "%s\n", power_zone->name);
+ return sysfs_emit(buf, "%s\n", power_zone->name);
}
static DEVICE_ATTR_RO(name);
@@ -438,7 +437,7 @@ static ssize_t enabled_show(struct device *dev,
mode = false;
}
- return sprintf(buf, "%d\n", mode);
+ return sysfs_emit(buf, "%d\n", mode);
}
static ssize_t enabled_store(struct device *dev,
--
2.43.0