From 3989e1b74119805b19cd708b62a6ba0a0b30295f Mon Sep 17 00:00:00 2001
From: Eduard Shishkin <edward6@linux.ibm.com>
Date: Tue, 17 Sep 2024 14:37:03 +0200
Subject: [PATCH] zipl/src: fix segfault on '--dry-run' for device-based dumps
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This fixes a segfault when the option '--dry-run' is specified for
device-based dumps (for which the bootmap file is created on a RAW
device, not formatted with a file system).

The actual status is that the option '--dry-run' for device-based
dumps is not implemented. The implementation is evaluated as not
trivial: In contrast with filesystem-based dumps, it is not possible
to simply make do with rename/unlink of temporary created bootmap.

The fixup returns error on any not file system based dumps being
created with the option '--dry-run'.

Signed-off-by: Eduard Shishkin <edward6@linux.ibm.com>
Reviewed-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
---
 zipl/src/bootmap.c | 34 +++++++++++-----------------------
 zipl/src/zipl.c    |  5 +++++
 2 files changed, 16 insertions(+), 23 deletions(-)

diff --git a/zipl/src/bootmap.c b/zipl/src/bootmap.c
index f4aec693..7d340156 100644
--- a/zipl/src/bootmap.c
+++ b/zipl/src/bootmap.c
@@ -1442,30 +1442,18 @@ static int prepare_build_program_table_device(struct job_data *job,
 	if (bis->skip_prepare)
 		/* skip the preparation work */
 		return 0;
+	if (dry_run) {
+		error_text("Option '--dry-run' is not implemented for this type of dump");
+		return -1;
+	}
 	/* Get full path of bootmap file */
-	if (!dry_run) {
-		bis->filename = misc_strdup(job->data.dump.device);
-		if (!bis->filename)
-			return -1;
-		bis->fd = misc_open_exclusive(bis->filename);
-		if (bis->fd == -1) {
-			error_text("Could not open file '%s'", bis->filename);
-			return -1;
-		}
-	} else {
-		bis->filename = misc_make_path(job->target.bootmap_dir,
-					       BOOTMAP_TEMPLATE_FILENAME);
-		if (!bis->filename)
-			return -1;
-		/* Create temporary bootmap file */
-		bis->fd = mkstemp(bis->filename);
-		if (bis->fd == -1) {
-			error_reason(strerror(errno));
-			error_text("Could not create file '%s':",
-				   bis->filename);
-			return -1;
-		}
-		bis->tmp_filename_created = 1;
+	bis->filename = misc_strdup(job->data.dump.device);
+	if (!bis->filename)
+		return -1;
+	bis->fd = misc_open_exclusive(bis->filename);
+	if (bis->fd == -1) {
+		error_text("Could not open file '%s'", bis->filename);
+		return -1;
 	}
 	/* Retrieve target device information */
 	if (disk_get_info(bis->filename, &job->target, &bis->info))
diff --git a/zipl/src/zipl.c b/zipl/src/zipl.c
index 2e0f1678..0f2345cd 100644
--- a/zipl/src/zipl.c
+++ b/zipl/src/zipl.c
@@ -181,6 +181,11 @@ main(int argc, char* argv[])
 		if (!job_dump_is_ngdump(job) &&
 		    (disk_is_tape(job->data.dump.device) ||
 		     !disk_type_is_scsi(&ext_type))) {
+			if (dry_run) {
+				error_text("Option '--dry-run' is not implemented for this type of dump");
+				rc = -1;
+				break;
+			}
 			rc = install_dump(job->data.dump.device, &job->target,
 					  job->data.dump.mem, job->data.dump.no_compress);
 			break;