hibernate-resume: introduce --clear-efi for clearing stale EFI var

src/hibernate-resume/hibernate-resume.c

@@ -17,6 +17,7 @@
 #include "terminal-util.h"
 
 static HibernateInfo arg_info = {};
+static bool arg_clear_efi = false;
 
 STATIC_DESTRUCTOR_REGISTER(arg_info, hibernate_info_done);
 
@@ -32,6 +33,7 @@ static int help(void) {
                "\n%sInitiate resume from hibernation.%s\n\n"
                "  -h --help            Show this help\n"
                "     --version         Show package version\n"
+               "     --clear-efi       Clear stale HibernateLocation EFI variable and exit\n"
                "\nSee the %s for details.\n",
                program_invocation_short_name,
                ansi_highlight(),
@@ -45,11 +47,13 @@ static int parse_argv(int argc, char *argv[]) {
 
         enum {
                 ARG_VERSION = 0x100,
+                ARG_CLEAR_EFI,
         };
 
         static const struct option options[] = {
                 { "help",      no_argument,       NULL, 'h'           },
                 { "version",   no_argument,       NULL, ARG_VERSION   },
+                { "clear-efi", no_argument,       NULL, ARG_CLEAR_EFI },
                 {}
         };
 
@@ -68,13 +72,21 @@ static int parse_argv(int argc, char *argv[]) {
                 case ARG_VERSION:
                         return version();
 
+                case ARG_CLEAR_EFI:
+                        arg_clear_efi = true;
+                        break;
+
                 case '?':
                         return -EINVAL;
 
                 default:
                         assert_not_reached();
                 }
 
+        if (argc > optind && arg_clear_efi)
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                       "Extraneous arguments specified with --clear-efi, refusing.");
+
         return 1;
 }
 
@@ -89,7 +101,8 @@ static int setup_hibernate_info_and_warn(void) {
         if (r < 0)
                 return r;
 
-        compare_hibernate_location_and_warn(&arg_info);
+        if (!arg_clear_efi)
+                compare_hibernate_location_and_warn(&arg_info);
 
         return 1;
 }
@@ -109,16 +122,29 @@ static int run(int argc, char *argv[]) {
 
         umask(0022);
 
-        if (!in_initrd())
+        if (!in_initrd() && !arg_clear_efi)
+                return log_error_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
+                                       "Not running in initrd, refusing to initiate resume from hibernation.");
+        if (in_initrd() && arg_clear_efi) {
+                log_info("Running in initrd, --clear-efi has no effect, exiting.");
                 return 0;
+        }
 
         if (argc <= optind) {
                 r = setup_hibernate_info_and_warn();
                 if (r <= 0)
                         return r;
 
                 if (arg_info.efi)
-                        (void) clear_efi_hibernate_location_and_warn();
+                        r = clear_efi_hibernate_location_and_warn();
+                else
+                        r = 0;
+
+                if (arg_clear_efi) {
+                        if (r > 0)
+                                log_notice("Successfully cleared stale HibernateLocation EFI variable.");
+                        return r;
+                }
         } else {
                 arg_info.device = ASSERT_PTR(argv[optind]);
 
@@ -129,6 +155,8 @@ static int run(int argc, char *argv[]) {
                 }
         }
 
+        assert(!arg_clear_efi);
+
         if (stat(arg_info.device, &st) < 0)
                 return log_error_errno(errno, "Failed to stat resume device '%s': %m", arg_info.device);