From: Heiko Carstens <heiko.carstens@de.ibm.com>
Date: Mon, 20 Jun 2016 11:31:55 +0000 (+0200)
Subject: s390/mm: use basic block for essa inline assembly
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=931641c639cea024d4462d79ad9716406bba7b19;p=linux-beck.git

s390/mm: use basic block for essa inline assembly

Use only simple inline assemblies which consist of a single basic
block if the register asm construct is being used.

Otherwise gcc would generate broken code if the compiler option
--sanitize-coverage=trace-pc would be used.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---

diff --git a/arch/s390/mm/page-states.c b/arch/s390/mm/page-states.c
index a90d45e9dfb0..3330ea124eec 100644
--- a/arch/s390/mm/page-states.c
+++ b/arch/s390/mm/page-states.c
@@ -34,20 +34,25 @@ static int __init cmma(char *str)
 }
 __setup("cmma=", cmma);
 
-void __init cmma_init(void)
+static inline int cmma_test_essa(void)
 {
 	register unsigned long tmp asm("0") = 0;
 	register int rc asm("1") = -EOPNOTSUPP;
 
-	if (!cmma_flag)
-		return;
 	asm volatile(
 		"       .insn rrf,0xb9ab0000,%1,%1,0,0\n"
 		"0:     la      %0,0\n"
 		"1:\n"
 		EX_TABLE(0b,1b)
 		: "+&d" (rc), "+&d" (tmp));
-	if (rc)
+	return rc;
+}
+
+void __init cmma_init(void)
+{
+	if (!cmma_flag)
+		return;
+	if (cmma_test_essa())
 		cmma_flag = 0;
 }