zipl/stage3: correctly handle diag308 response code

In case diag308 gives a response code 0x102 the stage3 loader can safely assume that no secure IPL is required since no IPL report block exists. Suggested-by: Marc Hartmayer <mhartmay@linux.ibm.com> Signed-off-by: Stefan Haberland <sth@linux.ibm.com> Reviewed-by: Marc Hartmayer <mhartmay@linux.ibm.com> Reviewed-by: Philipp Rudo <prudo@linux.ibm.com> Tested-by: Marc Hartmayer <mhartmay@linux.ibm.com> Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
ibm-s390-linux · Jul 17, 2020 · 943c5dc · 943c5dc
1 parent c367a6b
commit 943c5dc
Show file tree

Hide file tree

Showing 2 changed files with 12 additions and 14 deletions.
diff --git a/include/boot/s390.h b/include/boot/s390.h
@@ -286,6 +286,7 @@ enum diag308_subcode {
 
 enum diag308_rc {
 	DIAG308_RC_OK	      = 0x0001,
+	DIAG308_RC_NO_CONF    = 0x0102,
 };
 
 static __always_inline unsigned long diag308(unsigned long subcode, void *addr)

diff --git a/zipl/boot/stage3.c b/zipl/boot/stage3.c
@@ -57,18 +57,6 @@ static inline void __noreturn start_kernel(void)
 	while (1);
 }
 
-unsigned int store_ipl_parmblock(struct ipl_pl_hdr *pl_hdr)
-{
-	int rc;
-
-	rc = diag308(DIAG308_STORE, pl_hdr);
-	if (rc == DIAG308_RC_OK &&
-		pl_hdr->version <= IPL_MAX_SUPPORTED_VERSION)
-		return 0;
-
-	return 1;
-}
-
 unsigned int
 is_verified_address(unsigned long image_addr)
 {
@@ -126,9 +114,18 @@ secure_boot_enabled()
 	unsigned int rc;
 
 	pl_hdr = (void *)get_zeroed_page();
-	if (!pl_hdr || store_ipl_parmblock(pl_hdr))
+	switch (diag308(DIAG308_STORE, pl_hdr)) {
+	case DIAG308_RC_OK:
+		rc = pl_hdr->version <= IPL_MAX_SUPPORTED_VERSION &&
+			!!(pl_hdr->flags & IPL_FLAG_SECURE);
+		break;
+	case DIAG308_RC_NO_CONF:
+		rc = 0;
+		break;
+	default:
 		panic(ESECUREBOOT, "%s", msg_sipl_noparm);
-	rc = !!(pl_hdr->flags & IPL_FLAG_SECURE);
+		break;
+	}
 	free_page((unsigned long) pl_hdr);
 
 	return rc;