Le 27/10/2025 à 09:43, Thomas Gleixner a écrit :
Provide conveniance wrappers around scoped user access similiar to
put/get_user(), which reduce the usage sites to:
if (!get_user_inline(val, ptr))
return -EFAULT;
Should only be used if there is a demonstrable performance benefit.
Signed-off-by: Thomas Gleixner <[email protected]>
Reviewed-by: Christophe Leroy <[email protected]>
---
V5: Rename to inline
V4: Rename to scoped
---
include/linux/uaccess.h | 50
++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 50 insertions(+)
--- a/include/linux/uaccess.h
+++ b/include/linux/uaccess.h
@@ -825,6 +825,56 @@ for (bool done = false; !done; done = tr
#define scoped_user_rw_access(uptr, elbl) \
scoped_user_rw_access_size(uptr, sizeof(*(uptr)), elbl)
+/**
+ * get_user_inline - Read user data inlined
+ * @val: The variable to store the value read from user memory
+ * @usrc: Pointer to the user space memory to read from
+ *
+ * Return: 0 if successful, -EFAULT when faulted
+ *
+ * Inlined variant of get_user(). Only use when there is a demonstrable
+ * performance reason.
+ */
+#define get_user_inline(val, usrc) \
+({ \
+ __label__ efault; \
+ typeof(usrc) _tmpsrc = usrc; \
+ int _ret = 0; \
+ \
+ scoped_user_read_access(_tmpsrc, efault) \
+ unsafe_get_user(val, _tmpsrc, efault); \
+ if (0) { \
+ efault: \
+ _ret = -EFAULT; \
+ } \
+ _ret; \
+})
+
+/**
+ * put_user_inline - Write to user memory inlined
+ * @val: The value to write
+ * @udst: Pointer to the user space memory to write to
+ *
+ * Return: 0 if successful, -EFAULT when faulted
+ *
+ * Inlined variant of put_user(). Only use when there is a demonstrable
+ * performance reason.
+ */
+#define put_user_inline(val, udst) \
+({ \
+ __label__ efault; \
+ typeof(udst) _tmpdst = udst; \
+ int _ret = 0; \
+ \
+ scoped_user_write_access(_tmpdst, efault) \
+ unsafe_put_user(val, _tmpdst, efault); \
+ if (0) { \
+ efault: \
+ _ret = -EFAULT; \
+ } \
+ _ret; \
+})
+
#ifdef CONFIG_HARDENED_USERCOPY
void __noreturn usercopy_abort(const char *name, const char *detail,
bool to_user, unsigned long offset,
