s390-bios: Skip bootmap signature entries

Newer versions of zipl have the ability to write signature entries to the boot
script for secure boot. We don't yet support secure boot, but we need to skip
over signature entries while reading the boot script in order to maintain our
ability to boot guest operating systems that have a secure bootloader.

Signed-off-by: Jason J. Herne <jjherne@linux.ibm.com>
Reviewed-by: Farhan Ali <alifm@linux.ibm.com>
Message-Id: <1556543381-12671-1-git-send-email-jjherne@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>

1 files changed, 17 insertions, 2 deletions

diff --git a/pc-bios/s390-ccw/bootmap.c b/pc-bios/s390-ccw/bootmap.c
index 7aef65a..d13b7cb 100644
--- a/pc-bios/s390-ccw/bootmap.c
+++ b/pc-bios/s390-ccw/bootmap.c
@@ -254,7 +254,14 @@ static void run_eckd_boot_script(block_number_t bmt_block_nr,
     memset(sec, FREE_SPACE_FILLER, sizeof(sec));
     read_block(block_nr, sec, "Cannot read Boot Map Script");
 
-    for (i = 0; bms->entry[i].type == BOOT_SCRIPT_LOAD; i++) {
+    for (i = 0; bms->entry[i].type == BOOT_SCRIPT_LOAD ||
+                bms->entry[i].type == BOOT_SCRIPT_SIGNATURE; i++) {
+
+        /* We don't support secure boot yet, so we skip signature entries */
+        if (bms->entry[i].type == BOOT_SCRIPT_SIGNATURE) {
+            continue;
+        }
+
         address = bms->entry[i].address.load_address;
         block_nr = eckd_block_num(&bms->entry[i].blkptr.xeckd.bptr.chs);
 
@@ -489,7 +496,15 @@ static void zipl_run(ScsiBlockPtr *pte)
 
     /* Load image(s) into RAM */
     entry = (ComponentEntry *)(&header[1]);
-    while (entry->component_type == ZIPL_COMP_ENTRY_LOAD) {
+    while (entry->component_type == ZIPL_COMP_ENTRY_LOAD ||
+           entry->component_type == ZIPL_COMP_ENTRY_SIGNATURE) {
+
+        /* We don't support secure boot yet, so we skip signature entries */
+        if (entry->component_type == ZIPL_COMP_ENTRY_SIGNATURE) {
+            entry++;
+            continue;
+        }
+
         zipl_load_segment(entry);
 
         entry++;