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authorJoe Perches <joe@perches.com>2020-09-16 23:40:38 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-10-02 13:02:30 +0300
commit2efc459d06f1630001e3984854848a5647086232 (patch)
tree5489a527a724c8a17bf96df38744504f0acb74b3 /include/linux/sysfs.h
parente5e5fcef600e94d83c6542cdcca3ab6dada95946 (diff)
downloadlinux-2efc459d06f1630001e3984854848a5647086232.tar.xz
sysfs: Add sysfs_emit and sysfs_emit_at to format sysfs output
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. Validate the output buffer argument to be page aligned. Validate the offset len argument to be within the PAGE_SIZE buf. Signed-off-by: Joe Perches <joe@perches.com> Link: https://lore.kernel.org/r/884235202216d464d61ee975f7465332c86f76b2.1600285923.git.joe@perches.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include/linux/sysfs.h')
-rw-r--r--include/linux/sysfs.h15
1 files changed, 15 insertions, 0 deletions
diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h
index 34e84122f635..2caa34c1ca1a 100644
--- a/include/linux/sysfs.h
+++ b/include/linux/sysfs.h
@@ -329,6 +329,10 @@ int sysfs_groups_change_owner(struct kobject *kobj,
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, ...);
+__printf(3, 4)
+int sysfs_emit_at(char *buf, int at, const char *fmt, ...);
#else /* CONFIG_SYSFS */
@@ -576,6 +580,17 @@ static inline int sysfs_group_change_owner(struct kobject *kobj,
return 0;
}
+__printf(2, 3)
+static inline int sysfs_emit(char *buf, const char *fmt, ...)
+{
+ return 0;
+}
+
+__printf(3, 4)
+static inline int sysfs_emit_at(char *buf, int at, const char *fmt, ...)
+{
+ return 0;
+}
#endif /* CONFIG_SYSFS */
static inline int __must_check sysfs_create_file(struct kobject *kobj,