lazy-pages: always compile uffd.c

If CONFIG_HAS_UFFD is not defined an attempt to run the lazy pages daemon
will result in error message
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>

criu/Makefile.crtools

@@ -92,9 +92,7 @@ obj-$(CONFIG_COMPAT)	+= vdso-compat.o
 CFLAGS_REMOVE_vdso-compat.o	+= $(CFLAGS-ASAN) $(CFLAGS-GCOV)
 endif
 
-ifeq ($(UFFD),1)
 obj-y	+= uffd.o
-endif
 
 PROTOBUF_GEN := scripts/protobuf-gen.sh
 

criu/crtools.c

@@ -279,9 +279,7 @@ int main(int argc, char *argv[], char *envp[])
 		{ "timeout",			required_argument,	0, 1072 },
 		{ "external",			required_argument,	0, 1073	},
 		{ "empty-ns",			required_argument,	0, 1074	},
-#ifdef CONFIG_HAS_UFFD
 		{ "lazy-pages",			no_argument,		0, 1076 },
-#endif
 		BOOL_OPT("extra", &opts.check_extra_features),
 		BOOL_OPT("experimental", &opts.check_experimental_features),
 		{ "all",			no_argument,		0, 1079	},
@@ -522,11 +520,9 @@ int main(int argc, char *argv[], char *envp[])
 		case 1072:
 			opts.timeout = atoi(optarg);
 			break;
-#ifdef CONFIG_HAS_UFFD
 		case 1076:
 			opts.lazy_pages = true;
 			break;
-#endif
 		case 'M':
 			{
 				char *aux;
@@ -777,9 +773,7 @@ usage:
 "  criu page-server\n"
 "  criu service [<options>]\n"
 "  criu dedup\n"
-#ifdef CONFIG_HAS_UFFD
 "  criu lazy-pages -D DIR [<options>]\n"
-#endif
 "\n"
 "Commands:\n"
 "  dump           checkpoint a process/tree identified by pid\n"
@@ -823,12 +817,10 @@ usage:
 "                        restore making it the parent of the restored process\n"
 "  --freeze-cgroup       use cgroup freezer to collect processes\n"
 "  --weak-sysctls        skip restoring sysctls that are not available\n"
-#ifdef CONFIG_HAS_UFFD
 "  --lazy-pages          restore pages on demand\n"
 "                        this requires running a second instance of criu\n"
 "                        in lazy-pages mode: 'criu lazy-pages -D DIR'\n"
 "                        --lazy-pages and lazy-pages mode require userfaultfd\n"
-#endif
 "\n"
 "* External resources support:\n"
 "  --external RES        dump objects from this list as external resources:\n"

criu/include/crtools.h

@@ -25,11 +25,7 @@ extern int cr_restore_tasks(void);
 extern int convert_to_elf(char *elf_path, int fd_core);
 extern int cr_check(void);
 extern int cr_dedup(void);
-#ifdef CONFIG_HAS_UFFD
 extern int cr_lazy_pages(void);
-#else
-static inline int cr_lazy_pages() { return 0; };
-#endif /* CONFIG_HAS_UFFD */
 
 extern int check_add_feature(char *arg);
 extern void pr_check_features(const char *offset, const char *sep, int width);

criu/uffd.c

@@ -30,6 +30,8 @@
 #include "include/cr_options.h"
 #include "xmalloc.h"
 
+#ifdef CONFIG_HAS_UFFD
+
 #undef  LOG_PREFIX
 #define LOG_PREFIX "lazy-pages: "
 
@@ -664,3 +666,13 @@ int cr_lazy_pages()
 
 	return handle_requests(uffd);
 }
+
+#else /* CONFIG_HAS_UFFD */
+
+int cr_lazy_pages()
+{
+	pr_msg("userfaultfd system call is not supported, cannot start lazy-pages daemon\n");
+	return -1;
+}
+
+#endif /* CONFIG_HAS_UFFD */