From c3f15d52ad265bba0b21453d2d8b69f597092c25 Mon Sep 17 00:00:00 2001
From: Thomas Huth <thuth@redhat.com>
Date: Thu, 24 Jun 2021 14:50:47 -0400
Subject: [PATCH 3/3] pc-bios/s390-ccw: don't try to read the next block if end
 of chunk is reached

RH-Author: Thomas Huth <thuth@redhat.com>
Message-id: <20210624145047.483112-4-thuth@redhat.com>
Patchwork-id: 101763
O-Subject: [RHEL-8.2.0.z / RHEL-8.4.0.z qemu-kvm PATCH 3/3] pc-bios/s390-ccw: don't try to read the next block if end of chunk is reached
Bugzilla: 1975679
RH-Acked-by: Stefano Garzarella <sgarzare@redhat.com>
RH-Acked-by: Jon Maloy <jmaloy@redhat.com>
RH-Acked-by: Cornelia Huck <cohuck@redhat.com>

Don't read the block if a null block number is reached, because this means that
the end of chunk is reached.

Reviewed-by: Collin Walling <walling@linux.ibm.com>
Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Message-Id: <20210416074736.17409-1-mhartmay@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
(cherry picked from commit a6625d38cce3901a7c1cba069f0abcf743a293f1)
Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>
---
 pc-bios/s390-ccw/bootmap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pc-bios/s390-ccw/bootmap.c b/pc-bios/s390-ccw/bootmap.c
index 624f524331..8458b15cb6 100644
--- a/pc-bios/s390-ccw/bootmap.c
+++ b/pc-bios/s390-ccw/bootmap.c
@@ -212,7 +212,7 @@ static int eckd_get_boot_menu_index(block_number_t s1b_block_nr)
                 next_block_nr = eckd_block_num(&s1b->seek[i + 1].chs);
             }
 
-            if (next_block_nr) {
+            if (next_block_nr && !is_null_block_number(next_block_nr)) {
                 read_block(next_block_nr, s2_next_blk,
                            "Cannot read stage2 boot loader");
             }
-- 
2.27.0