[PATCH] sysfs: make sysfs_emit() return ssize_t

From: Alexey Dobriyan
Date: Mon Feb 05 2024 - 05:11:47 EST


sysfs_emit() is most often found in functions returning ssize_t
not int:

static ssize_t oops_count_show(...)
{
return sysfs_emit(page, ...);
}

This pattern results in sign-extension instruction between
sysfs_emit() return value (int) and caller return value (which is
ssize_t).

But it is better to do sign-extension once inside sysfs_emit()
then duplicate it at nearly every call site on 64-bit.

Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx>
---

fs/sysfs/file.c | 2 +-
include/linux/sysfs.h | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)

--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -739,7 +739,7 @@ EXPORT_SYMBOL_GPL(sysfs_change_owner);
*
* Returns number of characters written to @buf.
*/
-int sysfs_emit(char *buf, const char *fmt, ...)
+ssize_t sysfs_emit(char *buf, const char *fmt, ...)
{
va_list args;
int len;
--- a/include/linux/sysfs.h
+++ b/include/linux/sysfs.h
@@ -356,7 +356,7 @@ int sysfs_group_change_owner(struct kobject *kobj,
const struct attribute_group *groups, kuid_t kuid,
kgid_t kgid);
__printf(2, 3)
-int sysfs_emit(char *buf, const char *fmt, ...);
+ssize_t sysfs_emit(char *buf, const char *fmt, ...);
__printf(3, 4)
int sysfs_emit_at(char *buf, int at, const char *fmt, ...);

@@ -607,7 +607,7 @@ static inline int sysfs_group_change_owner(struct kobject *kobj,
}

__printf(2, 3)
-static inline int sysfs_emit(char *buf, const char *fmt, ...)
+static inline ssize_t sysfs_emit(char *buf, const char *fmt, ...)
{
return 0;
}