net: Comment copy_from_sockptr() explaining its behaviour

mmhal · Paolo Abeni · commit 49b2b973325a · 2024-11-28T08:57:42.000+01:00
copy_from_sockptr() has a history of misuse. Add a comment explaining that
the function follows API of copy_from_user(), i.e. returns 0 for success,
or number of bytes not copied on error.

Signed-off-by: Michal Luczaj &lt;mhal@rbox.co&gt;
Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
diff --git a/include/linux/sockptr.h b/include/linux/sockptr.h
@@ -53,6 +53,8 @@ static inline int copy_from_sockptr_offset(void *dst, sockptr_t src,
 /* Deprecated.
  * This is unsafe, unless caller checked user provided optlen.
  * Prefer copy_safe_from_sockptr() instead.
+ *
+ * Returns 0 for success, or number of bytes not copied on error.
  */
 static inline int copy_from_sockptr(void *dst, sockptr_t src, size_t size)
 {

Original file line number	Diff line number	Diff line change
`@@ -53,6 +53,8 @@ static inline int copy_from_sockptr_offset(void *dst, sockptr_t src,`
`53`	`53`	`/* Deprecated.`
`54`	`54`	`* This is unsafe, unless caller checked user provided optlen.`
`55`	`55`	`* Prefer copy_safe_from_sockptr() instead.`
	`56`	`+ *`
	`57`	`+ * Returns 0 for success, or number of bytes not copied on error.`
`56`	`58`	`*/`
`57`	`59`	`static inline int copy_from_sockptr(void *dst, sockptr_t src, size_t size)`
`58`	`60`	`{`