From 56ae2d8a1ee3a35e2eed4f4baa61f97184189b47 Mon Sep 17 00:00:00 2001
From: Thomas Huth <thuth@redhat.com>
Date: Tue, 18 May 2021 13:51:24 -0400
Subject: [PATCH 4/5] pc-bios/s390-ccw: break loop if a null block number is
 reached
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RH-Author: Thomas Huth <thuth@redhat.com>
Message-id: <20210518135125.191329-3-thuth@redhat.com>
Patchwork-id: 101549
O-Subject: [RHEL-8.5.0 qemu-kvm PATCH 2/3] pc-bios/s390-ccw: break loop if a null block number is reached
Bugzilla: 1942880
RH-Acked-by: Philippe Mathieu-Daudé <philmd@redhat.com>
RH-Acked-by: David Hildenbrand <david@redhat.com>
RH-Acked-by: Cornelia Huck <cohuck@redhat.com>

Break the loop if `cur_block_nr` is a null block number because this
means that the end of chunk is reached. In this case we will try to
boot the default entry.

Fixes: ba831b25262a ("s390-ccw: read stage2 boot loader data to find menu")
Reviewed-by: Collin Walling <walling@linux.ibm.com>
Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Message-Id: <20200924085926.21709-3-mhartmay@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
(cherry picked from commit 468184ec9024f4f7b55247f70ec57554e8a500d7)
Signed-off-by: Thomas Huth <thuth@redhat.com>
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 bb6e003270..624f524331 100644
--- a/pc-bios/s390-ccw/bootmap.c
+++ b/pc-bios/s390-ccw/bootmap.c
@@ -192,7 +192,7 @@ static int eckd_get_boot_menu_index(block_number_t s1b_block_nr)
     for (i = 0; i < STAGE2_BLK_CNT_MAX; i++) {
         cur_block_nr = eckd_block_num(&s1b->seek[i].chs);
 
-        if (!cur_block_nr) {
+        if (!cur_block_nr || is_null_block_number(cur_block_nr)) {
             break;
         }
 
-- 
2.27.0