On Wed, May 06, 2020 at 08:10:57PM +0200, Christophe Leroy wrote:

Le 06/05/2020 à 19:58, Segher Boessenkool a écrit :

quoted

quoted

 #define __put_user_asm_goto(x, addr, label, op)			\
 	asm volatile goto(					\
-		"1:	" op "%U1%X1 %0,%1	# put_user\n"	\
+		"1:	" op "%X1 %0,%1	# put_user\n"		\
 		EX_TABLE(1b, %l2)				\
 		:						\
-		: "r" (x), "m<>" (*addr)				\
+		: "r" (x), "m" (*addr)				\
 		:						\
 		: label)

Like that.  But you will have to do that to *all* places we use the "<>"
constraints, or wait for more stuff to fail?  And, there probably are
places we *do* want update form insns used (they do help in some loops,
for example)?

AFAICT, git grep "m<>" provides no result.

Ah, okay.

However many places have %Ux:

<snip>

Yes, all of those are from when "m" still meant what "m<>" is now.  For
seeing how many update form insns can be generated (and how much that
matters), these all should be fixed, at a minimum.


Segher