Re: [PATCH v2 32/62] objtool: Suppress section skipping warnings with --dryrun

[Peter Zijlstra]

On Thu, Jun 05, 2025 at 09:32:46AM +0200, Peter Zijlstra wrote:

> > But also, feel free to resurrect --backup, or you can yell at me to do
> > it as the backup code changed a bit.
> 
> I have the patch somewhere, failed to send it out. I'll try and dig it
> out later today.

This is what I had. Wasn't sure we wanted to make -v imply --backup ?

I'm used to stealing the objtool arguments from V=1 builds. I suppose
the print_args thing is easier, might get used to it eventually.


diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c
index 80239843e9f0..7d8f99cf9b0b 100644
--- a/tools/objtool/builtin-check.c
+++ b/tools/objtool/builtin-check.c
@@ -101,6 +101,7 @@ static const struct option check_options[] = {
        OPT_BOOLEAN(0,   "stats", &opts.stats, "print statistics"),
        OPT_BOOLEAN('v', "verbose", &opts.verbose, "verbose warnings"),
        OPT_BOOLEAN(0,   "Werror", &opts.werror, "return error on warnings"),
+       OPT_BOOLEAN(0,   "backup", &opts.backup, "create a backup (.orig) file 
on error"),
 
        OPT_END(),
 };
@@ -244,13 +245,10 @@ static void save_argv(int argc, const char **argv)
        };
 }
 
-void print_args(void)
+static void make_backup(void)
 {
        char *backup = NULL;
 
-       if (opts.output || opts.dryrun)
-               goto print;
-
        /*
         * Make a backup before kbuild deletes the file so the error
         * can be recreated without recompiling or relinking.
@@ -258,17 +256,19 @@ void print_args(void)
        backup = malloc(strlen(objname) + strlen(ORIG_SUFFIX) + 1);
        if (!backup) {
                ERROR_GLIBC("malloc");
-               goto print;
+               return;
        }
 
        strcpy(backup, objname);
        strcat(backup, ORIG_SUFFIX);
        if (copy_file(objname, backup)) {
                backup = NULL;
-               goto print;
+               return;
        }
+}
 
-print:
+void print_args(void)
+{
        /*
         * 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.
@@ -278,10 +278,7 @@ void print_args(void)
        for (int i = 1; i < orig_argc; i++) {
                char *arg = orig_argv[i];
 
-               if (backup && !strcmp(arg, objname))
-                       fprintf(stderr, " %s -o %s", backup, objname);
-               else
-                       fprintf(stderr, " %s", arg);
+               fprintf(stderr, " %s", arg);
        }
 
        fprintf(stderr, "\n");
@@ -324,8 +321,11 @@ int objtool_run(int argc, const char **argv)
        }
 
        ret = check(file);
-       if (ret)
+       if (ret) {
+               if (opts.backup)
+                       make_backup();
                return ret;
+       }
 
        if (!opts.dryrun && file->elf->changed && elf_write(file->elf))
                return 1;
diff --git a/tools/objtool/include/objtool/builtin.h 
b/tools/objtool/include/objtool/builtin.h
index 6b08666fa69d..97c36fb1fe9a 100644
--- a/tools/objtool/include/objtool/builtin.h
+++ b/tools/objtool/include/objtool/builtin.h
@@ -39,6 +39,7 @@ struct opts {
        bool stats;
        bool verbose;
        bool werror;
+       bool backup;
 };
 
 extern struct opts opts;