The following commit has been merged into the objtool/core branch of tip:

Commit-ID:     2b91479776b66cd815e339d420abbf4ae047bfb2
Gitweb:        https://git.kernel.org/tip/2b91479776b66cd815e339d420abbf4ae047bfb2
Author:        Josh Poimboeuf <jpoimboe@kernel.org>
AuthorDate:    Wed, 17 Sep 2025 09:03:43 -07:00
Committer:     Josh Poimboeuf <jpoimboe@kernel.org>
CommitterDate: Tue, 14 Oct 2025 14:46:48 -07:00

objtool: Resurrect --backup option

The --backup option was removed with the following commit:

  aa8b3e64fd39 ("objtool: Create backup on error and print args")

... which tied the backup functionality to --verbose, and only for
warnings/errors.

It's a bit inelegant and out of scope to tie that to --verbose.

Bring back the old --backup option, but with the new behavior: only on
warnings/errors, and print the args to make it easier to recreate.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Petr Mladek <pmladek@suse.com>
Tested-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
 tools/objtool/builtin-check.c           | 25 ++++++++++--------------
 tools/objtool/check.c                   |  4 +++-
 tools/objtool/include/objtool/builtin.h |  3 ++-
 3 files changed, 16 insertions(+), 16 deletions(-)

diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c
index 2aa28af..2abac92 100644
--- a/tools/objtool/builtin-check.c
+++ b/tools/objtool/builtin-check.c
@@ -92,6 +92,7 @@ static const struct option check_options[] = {
 
 	OPT_GROUP("Options:"),
 	OPT_BOOLEAN(0,   "backtrace", &opts.backtrace, "unwind on error"),
+	OPT_BOOLEAN(0,   "backup", &opts.backup, "create backup (.orig) file on warning/error"),
 	OPT_BOOLEAN(0,   "dry-run", &opts.dryrun, "don't write modifications"),
 	OPT_BOOLEAN(0,   "link", &opts.link, "object is a linked object"),
 	OPT_BOOLEAN(0,   "module", &opts.module, "object is part of a kernel module"),
@@ -246,12 +247,9 @@ static void save_argv(int argc, const char **argv)
 	}
 }
 
-void print_args(void)
+int make_backup(void)
 {
-	char *backup = NULL;
-
-	if (opts.output || opts.dryrun)
-		goto print;
+	char *backup;
 
 	/*
 	 * Make a backup before kbuild deletes the file so the error
@@ -260,33 +258,32 @@ void print_args(void)
 	backup = malloc(strlen(objname) + strlen(ORIG_SUFFIX) + 1);
 	if (!backup) {
 		ERROR_GLIBC("malloc");
-		goto print;
+		return 1;
 	}
 
 	strcpy(backup, objname);
 	strcat(backup, ORIG_SUFFIX);
-	if (copy_file(objname, backup)) {
-		backup = NULL;
-		goto print;
-	}
+	if (copy_file(objname, backup))
+		return 1;
 
-print:
 	/*
-	 * Print the cmdline args to make it easier to recreate.  If '--output'
-	 * wasn't used, add it to the printed args with the backup as input.
+	 * Print the cmdline args to make it easier to recreate.
 	 */
+
 	fprintf(stderr, "%s", orig_argv[0]);
 
 	for (int i = 1; i < orig_argc; i++) {
 		char *arg = orig_argv[i];
 
-		if (backup && !strcmp(arg, objname))
+		/* Modify the printed args to use the backup */
+		if (!opts.output && !strcmp(arg, objname))
 			fprintf(stderr, " %s -o %s", backup, objname);
 		else
 			fprintf(stderr, " %s", arg);
 	}
 
 	fprintf(stderr, "\n");
+	return 0;
 }
 
 int objtool_run(int argc, const char **argv)
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index e567a62..b63f7c4 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -4824,9 +4824,11 @@ out:
 	if (opts.verbose) {
 		if (opts.werror && warnings)
 			WARN("%d warning(s) upgraded to errors", warnings);
-		print_args();
 		disas_warned_funcs(file);
 	}
 
+	if (opts.backup && make_backup())
+		return 1;
+
 	return ret;
 }
diff --git a/tools/objtool/include/objtool/builtin.h b/tools/objtool/include/objtool/builtin.h
index ab22673..7d559a2 100644
--- a/tools/objtool/include/objtool/builtin.h
+++ b/tools/objtool/include/objtool/builtin.h
@@ -30,6 +30,7 @@ struct opts {
 
 	/* options: */
 	bool backtrace;
+	bool backup;
 	bool dryrun;
 	bool link;
 	bool mnop;
@@ -48,6 +49,6 @@ int cmd_parse_options(int argc, const char **argv, const char * const usage[]);
 
 int objtool_run(int argc, const char **argv);
 
-void print_args(void);
+int make_backup(void);
 
 #endif /* _BUILTIN_H */