[CRIU] [PATCH 2/5] kdat: Relax uffd checks

[Pavel Emelyanov]

Always check for uffd features.

Signed-off-by: Pavel Emelyanov <xemul at virtuozzo.com>
---
 criu/cr-check.c        | 2 +-
 criu/cr-service.c      | 4 ++--
 criu/include/kerndat.h | 2 +-
 criu/kerndat.c         | 8 ++++----
 criu/uffd.c            | 2 +-
 5 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/criu/cr-check.c b/criu/cr-check.c
index 8d13504..8ef5d23 100644
--- a/criu/cr-check.c
+++ b/criu/cr-check.c
@@ -1075,7 +1075,7 @@ static int check_uffd(void)
 		UFFD_FEATURE_EVENT_UNMAP |
 		UFFD_FEATURE_EVENT_REMOVE;
 
-	if (kerndat_uffd(true))
+	if (kerndat_uffd())
 		return -1;
 
 	if ((kdat.uffd_features & features) != features) {
diff --git a/criu/cr-service.c b/criu/cr-service.c
index d59ab8b..73a32d2 100644
--- a/criu/cr-service.c
+++ b/criu/cr-service.c
@@ -893,7 +893,7 @@ static int handle_feature_check(int sk, CriuReq * msg)
 
 		if ((msg->features->has_lazy_pages == 1) &&
 		    (msg->features->lazy_pages == true)) {
-			ret = kerndat_uffd(true);
+			ret = kerndat_uffd();
 
 			/*
 			 * Not checking for specific UFFD features yet.
@@ -902,7 +902,7 @@ static int handle_feature_check(int sk, CriuReq * msg)
 			 * be extended in the future for a more detailed
 			 * UFFD feature check.
 			 */
-			if (ret)
+			if (ret || (kdat.uffd_features == 0))
 				feat.lazy_pages = false;
 			else
 				feat.lazy_pages = true;
diff --git a/criu/include/kerndat.h b/criu/include/kerndat.h
index b8508ff..4945a4b 100644
--- a/criu/include/kerndat.h
+++ b/criu/include/kerndat.h
@@ -70,7 +70,7 @@ enum {
 extern int kerndat_fs_virtualized(unsigned int which, u32 kdev);
 
 extern int kerndat_tcp_repair();
-extern int kerndat_uffd(bool need_uffd);
+extern int kerndat_uffd(void);
 extern int kerndat_has_nspid(void);
 
 #endif /* __CR_KERNDAT_H__ */
diff --git a/criu/kerndat.c b/criu/kerndat.c
index 9c47b13..416b1bc 100644
--- a/criu/kerndat.c
+++ b/criu/kerndat.c
@@ -586,7 +586,7 @@ static int kerndat_compat_restore(void)
 	return 0;
 }
 
-int kerndat_uffd(bool need_uffd)
+int kerndat_uffd(void)
 {
 	struct uffdio_api uffdio_api;
 	int uffd;
@@ -598,8 +598,8 @@ int kerndat_uffd(bool need_uffd)
 	 * on this system. Additionally checking for ENOSYS
 	 * makes sure it is actually not implemented.
 	 */
-	if (uffd == -1 && errno == ENOSYS) {
-		if (!need_uffd)
+	if (uffd == -1) {
+		if (errno == ENOSYS)
 			return 0;
 
 		pr_err("Lazy pages are not available\n");
@@ -718,7 +718,7 @@ int kerndat_init_rst(void)
 	if (!ret)
 		ret = kerndat_compat_restore();
 	if (!ret)
-		ret = kerndat_uffd(opts.lazy_pages);
+		ret = kerndat_uffd();
 	if (!ret)
 		ret = kerndat_socket_netns();
 	if (!ret)
diff --git a/criu/uffd.c b/criu/uffd.c
index b2cf102..7caa840 100644
--- a/criu/uffd.c
+++ b/criu/uffd.c
@@ -1115,7 +1115,7 @@ int cr_lazy_pages(bool daemon)
 	int lazy_sk;
 	int ret;
 
-	if (kerndat_uffd(true))
+	if (kerndat_uffd() || (kdat.uffd_features == 0))
 		return -1;
 
 	if (prepare_dummy_pstree())
-- 
2.5.5