[PATCH v5 2/4] s390/sclp_tty: Make use of sclp_gds_for_each()

[Alexander Egorenkov <egorenar@linux.ibm.com>]

Replace manual and error-prone iteration over entries of a GDS {sub}vector
with sclp_gds_for_each() which deals with erroneous entries in GDS
{sub}vectors more safely.

Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Suggested-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Fixes: 30c2df51173e ("[S390] sclp: event buffer dissection")
---
 drivers/s390/char/sclp_tty.c | 30 +++++++++++++++---------------
 1 file changed, 15 insertions(+), 15 deletions(-)

diff --git a/drivers/s390/char/sclp_tty.c b/drivers/s390/char/sclp_tty.c
index 0a92d08830e7..4353890bbf8a 100644
--- a/drivers/s390/char/sclp_tty.c
+++ b/drivers/s390/char/sclp_tty.c
@@ -418,38 +418,38 @@ static void sclp_get_input(struct gds_subvector *sv)
 
 static inline void sclp_eval_selfdeftextmsg(struct gds_subvector *sv)
 {
-	void *end;
-
-	end = (void *) sv + sv->length;
-	for (sv = sv + 1; (void *) sv < end; sv = (void *) sv + sv->length)
+	void *start = sv + 1;
+	void *end = (void *) sv + sv->length;
+	int n;
+	sclp_gds_for_each(sv, n, start, end) {
 		if (sv->key == 0x30)
 			sclp_get_input(sv);
+	}
 }
 
 static inline void sclp_eval_textcmd(struct gds_vector *v)
 {
+	void *start = v + 1;
+	void *end = (void *) v + v->length;
 	struct gds_subvector *sv;
-	void *end;
-
-	end = (void *) v + v->length;
-	for (sv = (struct gds_subvector *) (v + 1);
-	     (void *) sv < end; sv = (void *) sv + sv->length)
+	int n;
+	sclp_gds_for_each(sv, n, start, end) {
 		if (sv->key == GDS_KEY_SELFDEFTEXTMSG)
 			sclp_eval_selfdeftextmsg(sv);
-
+	}
 }
 
 static inline void sclp_eval_cpmsu(struct gds_vector *v)
 {
-	void *end;
-
-	end = (void *) v + v->length;
-	for (v = v + 1; (void *) v < end; v = (void *) v + v->length)
+	void *start = v + 1;
+	void *end = (void *) v + v->length;
+	int n;
+	sclp_gds_for_each(v, n, start, end) {
 		if (v->gds_id == GDS_ID_TEXTCMD)
 			sclp_eval_textcmd(v);
+	}
 }
 
-
 static inline void sclp_eval_mdsmu(struct gds_vector *v)
 {
 	v = sclp_find_gds_vector(v + 1, (void *) v + v->length, GDS_ID_CPMSU);
-- 
2.53.0