criu: remove FEATURE_TEST_MEMFD

It isn't required, __NR_memfd_create is defined in syscall-codes.h.

With this patch, we can run all tests in travis-ci, because there
a kernel has support of memfd, but __NR_memfd_create isn't defined
in installed headers
Signed-off-by: Andrew Vagin <avagin@virtuozzo.com>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>

criu/kerndat.c

@@ -329,7 +329,6 @@ static int get_last_cap(void)
 	return sysctl_op(req, ARRAY_SIZE(req), CTL_READ, 0);
 }
 
-#ifdef CONFIG_HAS_MEMFD
 static bool kerndat_has_memfd_create(void)
 {
 	int ret;
@@ -347,13 +346,6 @@ static bool kerndat_has_memfd_create(void)
 
 	return 0;
 }
-#else
-static bool kerndat_has_memfd_create(void)
-{
-	kdat.has_memfd = false;
-	return 0;
-}
-#endif
 
 static int get_task_size(void)
 {

criu/parasite-syscall.c

@@ -1202,7 +1202,6 @@ static int parasite_mmap_exchange(struct parasite_ctl *ctl, unsigned long size)
 	return 0;
 }
 
-#ifdef CONFIG_HAS_MEMFD
 static int parasite_memfd_exchange(struct parasite_ctl *ctl, unsigned long size)
 {
 	void *where = (void *)ctl->syscall_ip + BUILTIN_SYSCALL_SIZE;
@@ -1279,12 +1278,6 @@ err_cure:
 	syscall_seized(ctl, __NR_close, &sret, fd, 0, 0, 0, 0, 0);
 	return -1;
 }
-#else
-static int parasite_memfd_exchange(struct parasite_ctl *ctl, unsigned long size)
-{
-	return 1;
-}
-#endif
 
 int parasite_map_exchange(struct parasite_ctl *ctl, unsigned long size)
 {

criu/shmem.c

@@ -422,7 +422,6 @@ static int open_shmem(int pid, struct vma_area *vma)
 	}
 
 	flags = MAP_SHARED;
-#ifdef CONFIG_HAS_MEMFD
 	if (kdat.has_memfd) {
 		f = syscall(SYS_memfd_create, "", 0);
 		if (f < 0) {
@@ -436,7 +435,6 @@ static int open_shmem(int pid, struct vma_area *vma)
 		}
 		flags |= MAP_FILE;
 	} else
-#endif
 		flags |= MAP_ANONYMOUS;
 
 	/*

scripts/feature-tests.mak

@@ -74,19 +74,3 @@ int main(int argc, char *argv[], char *envp[])
 }
 
 endef
-
-define FEATURE_TEST_MEMFD
-
-#include <unistd.h>
-#include <sys/syscall.h>
-
-int main(void)
-{
-#ifdef __NR_memfd_create
-	return 0;
-#else
-# error No memfd support
-#endif
-}
-
-endef