Re: [PATCH 2/2] uaccess: minimize INLINE_COPY_USER-related ifdefery

["Christophe Leroy (CS GROUP)" <chleroy@kernel.org>]

Le 25/03/2026 à 17:33, Yury Norov a écrit :
> Now that we've got the same knob selecting inline vs outline copy_to_user()
> and copy_from_user(), we can simplify the corresponding logic in the
> uaccess.h.

I think we should get rid of ifdefery completly, see below. And with 
comment to previous patch,

     __is_defined(INLINE_COPY_TO_USER)

becomes

     !IS_ENABLED(CONFIG_ARCH_WANT_OUTLINE_USER_COPY)

diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h
index 327f967a24b8..02a05dd61a77 100644
--- a/include/linux/uaccess.h
+++ b/include/linux/uaccess.h
@@ -190,10 +190,9 @@ _inline_copy_from_user(void *to, const void __user 
*from, unsigned long n)
  	memset(to + (n - res), 0, res);
  	return res;
  }
-#ifndef INLINE_COPY_FROM_USER
+
  extern __must_check unsigned long
  _copy_from_user(void *, const void __user *, unsigned long);
-#endif

  static inline __must_check unsigned long
  _inline_copy_to_user(void __user *to, const void *from, unsigned long n)
@@ -207,21 +206,19 @@ _inline_copy_to_user(void __user *to, const void 
*from, unsigned long n)
  	}
  	return n;
  }
-#ifndef INLINE_COPY_TO_USER
+
  extern __must_check unsigned long
  _copy_to_user(void __user *, const void *, unsigned long);
-#endif

  static __always_inline unsigned long __must_check
  copy_from_user_common(void *to, const void __user *from, unsigned long 
n, bool partial)
  {
  	if (!check_copy_size(to, n, false))
  		return n;
-#ifdef INLINE_COPY_FROM_USER
-	return _inline_copy_from_user(to, from, n);
-#else
-	return _copy_from_user(to, from, n);
-#endif
+	if (__is_defined(INLINE_COPY_FROM_USER))
+		return _inline_copy_from_user(to, from, n);
+	else
+		return _copy_from_user(to, from, n);
  }

  static __always_inline unsigned long __must_check
@@ -242,11 +239,10 @@ copy_to_user_common(void __user *to, const void 
*from, unsigned long n, bool par
  	if (!check_copy_size(from, n, true))
  		return n;

-#ifdef INLINE_COPY_TO_USER
-	return _inline_copy_to_user(to, from, n);
-#else
-	return _copy_to_user(to, from, n);
-#endif
+	if (__is_defined(INLINE_COPY_TO_USER))
+		return _inline_copy_to_user(to, from, n);
+	else
+		return _copy_to_user(to, from, n);
  }

  static __always_inline unsigned long __must_check


Christophe