From 3d7ff6c57357e1fb8453b26200cfd239e9cdaa72 Mon Sep 17 00:00:00 2001
From: Thomas Huth <thuth@redhat.com>
Date: Thu, 24 Jun 2021 14:50:46 -0400
Subject: [PATCH 2/3] pc-bios/s390-ccw: break loop if a null block number is
 reached

RH-Author: Thomas Huth <thuth@redhat.com>
Message-id: <20210624145047.483112-3-thuth@redhat.com>
Patchwork-id: 101762
O-Subject: [RHEL-8.2.0.z / RHEL-8.4.0.z qemu-kvm PATCH 2/3] pc-bios/s390-ccw: break loop if a null block number 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>

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: 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

