[CRIU] [PATCH 02/11] lazy-pages: always compile uffd.c

[Mike Rapoport]

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 at linux.vnet.ibm.com>
---
 criu/Makefile.crtools  |  2 --
 criu/crtools.c         |  8 --------
 criu/include/crtools.h |  4 ----
 criu/uffd.c            | 12 ++++++++++++
 4 files changed, 12 insertions(+), 14 deletions(-)

diff --git a/criu/Makefile.crtools b/criu/Makefile.crtools
index d610d2f..79fd77a 100644
--- a/criu/Makefile.crtools
+++ b/criu/Makefile.crtools
@@ -82,9 +82,7 @@ obj-y			+= pie-util-vdso.o
 obj-y			+= vdso.o
 endif
 
-ifeq ($(UFFD),1)
 obj-y	+= uffd.o
-endif
 
 PROTOBUF_GEN := $(SRC_DIR)/scripts/protobuf-gen.sh
 
diff --git a/criu/crtools.c b/criu/crtools.c
index d4c5731..93ca90b 100644
--- a/criu/crtools.c
+++ b/criu/crtools.c
@@ -317,9 +317,7 @@ int main(int argc, char *argv[], char *envp[])
 		{ "external",			required_argument,	0, 1073	},
 		{ "empty-ns",			required_argument,	0, 1074	},
 		{ "unshare",			required_argument,	0, 1075 },
-#ifdef CONFIG_HAS_UFFD
 		{ "lazy-pages",			no_argument,		0, 1076 },
-#endif
 		{ "extra",			no_argument,		0, 1077	},
 		{ "experimental",		no_argument,		0, 1078	},
 		{ "all",			no_argument,		0, 1079	},
@@ -582,11 +580,9 @@ int main(int argc, char *argv[], char *envp[])
 			if (parse_unshare_arg(optarg))
 				return -1;
 			break;
-#ifdef CONFIG_HAS_UFFD
 		case 1076:
 			opts.lazy_pages = true;
 			break;
-#endif
 		case 'M':
 			{
 				char *aux;
@@ -801,9 +797,7 @@ 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"
@@ -843,12 +837,10 @@ usage:
 "  --unshare FLAGS       what namespaces to unshare when restoring\n"
 "  --freeze-cgroup\n"
 "                        use cgroup freezer to collect processes\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"
 "* Special resources support:\n"
 "  -x|--" USK_EXT_PARAM "inode,.." "      allow external unix connections (optionally can be assign socket's inode that allows one-sided dump)\n"
diff --git a/criu/include/crtools.h b/criu/include/crtools.h
index e58b2be..00b7621 100644
--- a/criu/include/crtools.h
+++ b/criu/include/crtools.h
@@ -26,11 +26,7 @@ extern int convert_to_elf(char *elf_path, int fd_core);
 extern int cr_check(void);
 extern int cr_exec(int pid, char **opts);
 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 prepare_task_entries(void);
 
 extern int check_add_feature(char *arg);
diff --git a/criu/uffd.c b/criu/uffd.c
index 3752a8c..c7aea0f 100644
--- a/criu/uffd.c
+++ b/criu/uffd.c
@@ -28,6 +28,8 @@
 #include "include/cr_options.h"
 #include "xmalloc.h"
 
+#ifdef CONFIG_HAS_UFFD
+
 #undef  LOG_PREFIX
 #define LOG_PREFIX "lazy-pages: "
 
@@ -660,3 +662,13 @@ 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 */
-- 
1.9.1