[PATCH v4 01/10] sparc64: return from the generic clear_page implementation

[Magnus Lindholm]

GENclear_page falls through into generic_patch_pageops after clearing
its page. The patcher then rewrites kernel text on each invocation.
This executes 45 extra instructions, including six stores and three
FLUSH instructions, before returning.

Return once the clear loop completes, as GENcopy_page does. This affects
processors using the generic page-operation fallback.

Fixes: 6c70b6fc7b6f ("[SPARC64]: Do not assume sun4v chips have load-twin/store-init support.")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Magnus Lindholm <linmag7@xxxxxxxxx>
---
 arch/sparc/lib/GENpage.S | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/sparc/lib/GENpage.S b/arch/sparc/lib/GENpage.S
index c143c4d1de3f..6ce11108e143 100644
--- a/arch/sparc/lib/GENpage.S
+++ b/arch/sparc/lib/GENpage.S
@@ -48,6 +48,9 @@ GENclear_user_page:
 	bne,pt	%xcc, 1b
 	 add	%o0, 64, %o0
 
+	retl
+	 nop
+
 #define BRANCH_ALWAYS	0x10680000
 #define NOP		0x01000000
 #define GEN_DO_PATCH(OLD, NEW)	\
-- 
2.43.0