[LTP] [PATCH v3] userfaultfd: Add new test using UFFDIO_CONTINUE

[LTP] [PATCH v3] userfaultfd: Add new test using UFFDIO_CONTINUE

[Ricardo Branco]

Add test to exercise UFFDIO_CONTINUE on a shared-memory mapping with
UFFD_PAGEFAULT_FLAG_MINOR. The test populates a memfd-backed page,
drops only the PTEs with MADV_DONTNEED, verifies that the resulting
fault is reported as MINOR, updates the page cache from the handler
thread, and resumes execution with UFFDIO_CONTINUE.

Signed-off-by: Ricardo Branco <rbranco@suse.de>
---
 include/lapi/userfaultfd.h                    |   1 +
 runtest/syscalls                              |   1 +
 .../kernel/syscalls/userfaultfd/.gitignore    |   1 +
 .../kernel/syscalls/userfaultfd/Makefile      |   1 +
 .../syscalls/userfaultfd/userfaultfd07.c      | 152 ++++++++++++++++++
 5 files changed, 156 insertions(+)
 create mode 100644 testcases/kernel/syscalls/userfaultfd/userfaultfd07.c

diff --git a/include/lapi/userfaultfd.h b/include/lapi/userfaultfd.h
index aab3890b7..c05b8dbf5 100644
--- a/include/lapi/userfaultfd.h
+++ b/include/lapi/userfaultfd.h
@@ -171,6 +171,7 @@ struct uffdio_zeropage {
 #ifndef UFFD_PAGEFAULT_FLAG_MINOR
 #define UFFD_FEATURE_MINOR_HUGETLBFS		(1<<9)
 #define UFFDIO_REGISTER_MODE_MINOR	((__u64)1<<2)
+#define UFFD_PAGEFAULT_FLAG_MINOR	(1<<2)
 
 #define _UFFDIO_CONTINUE		(0x07)
 #define UFFDIO_CONTINUE		_IOWR(UFFDIO, _UFFDIO_CONTINUE,	\
diff --git a/runtest/syscalls b/runtest/syscalls
index 6ba0227a8..534140f42 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls
@@ -1780,6 +1780,7 @@ userfaultfd03 userfaultfd03
 userfaultfd04 userfaultfd04
 userfaultfd05 userfaultfd05
 userfaultfd06 userfaultfd06
+userfaultfd07 userfaultfd07
 
 ustat01 ustat01
 ustat02 ustat02
diff --git a/testcases/kernel/syscalls/userfaultfd/.gitignore b/testcases/kernel/syscalls/userfaultfd/.gitignore
index bc32fdf3b..3478a162e 100644
--- a/testcases/kernel/syscalls/userfaultfd/.gitignore
+++ b/testcases/kernel/syscalls/userfaultfd/.gitignore
@@ -4,3 +4,4 @@
 /userfaultfd04
 /userfaultfd05
 /userfaultfd06
+/userfaultfd07
diff --git a/testcases/kernel/syscalls/userfaultfd/Makefile b/testcases/kernel/syscalls/userfaultfd/Makefile
index 3252e47df..257249e88 100644
--- a/testcases/kernel/syscalls/userfaultfd/Makefile
+++ b/testcases/kernel/syscalls/userfaultfd/Makefile
@@ -17,3 +17,4 @@ userfaultfd03: CFLAGS += -pthread
 userfaultfd04: CFLAGS += -pthread
 userfaultfd05: CFLAGS += -pthread
 userfaultfd06: CFLAGS += -pthread
+userfaultfd07: CFLAGS += -pthread
diff --git a/testcases/kernel/syscalls/userfaultfd/userfaultfd07.c b/testcases/kernel/syscalls/userfaultfd/userfaultfd07.c
new file mode 100644
index 000000000..9d37589e8
--- /dev/null
+++ b/testcases/kernel/syscalls/userfaultfd/userfaultfd07.c
@@ -0,0 +1,152 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2026 SUSE LLC
+ * Author: Ricardo Branco <rbranco@suse.com>
+ */
+
+/*\
+ * Force a pagefault event and handle it using :manpage:`userfaultfd(2)`
+ * from a different thread testing UFFDIO_CONTINUE.
+ */
+
+#include "config.h"
+#include <poll.h>
+#include <unistd.h>
+#include "tst_test.h"
+#include "tst_safe_macros.h"
+#include "tst_safe_prw.h"
+#include "tst_safe_pthread.h"
+#include "lapi/memfd.h"
+#include "lapi/userfaultfd.h"
+#include "lapi/syscalls.h"
+
+static long page_size;
+static char *page;
+static int uffd = -1;
+static int memfd = -1;
+
+static void set_pages(void)
+{
+	char ch = 'A';
+
+	page_size = SAFE_SYSCONF(_SC_PAGE_SIZE);
+
+	memfd = sys_memfd_create("ltp-uffd-continue", MFD_CLOEXEC);
+	if (memfd < 0)
+		tst_brk(TBROK | TERRNO, "memfd_create failed");
+
+	SAFE_FTRUNCATE(memfd, page_size);
+
+	/*
+	 * Populate page cache so that after MADV_DONTNEED the next access
+	 * can generate a MINOR fault rather than a MISSING fault.
+	 */
+	SAFE_PWRITE(1, memfd, &ch, 1, 0);
+
+	page = SAFE_MMAP(NULL, page_size, PROT_READ, MAP_SHARED, memfd, 0);
+}
+
+static void reset_pages(void)
+{
+	if (page) {
+		SAFE_MUNMAP(page, page_size);
+		page = NULL;
+	}
+
+	if (memfd != -1)
+		memfd = -1;
+
+	if (uffd != -1)
+		SAFE_CLOSE(uffd);
+}
+
+static void *handle_thread(void *arg LTP_ATTRIBUTE_UNUSED)
+{
+	static struct uffd_msg msg;
+	struct uffdio_continue uffdio_continue = {};
+	struct pollfd pollfd;
+	int nready;
+	char z = 'Z';
+
+	pollfd.fd = uffd;
+	pollfd.events = POLLIN;
+	nready = poll(&pollfd, 1, -1);
+	if (nready == -1)
+		tst_brk(TBROK | TERRNO, "Error on poll");
+
+	SAFE_READ(1, uffd, &msg, sizeof(msg));
+
+	if (msg.event != UFFD_EVENT_PAGEFAULT)
+		tst_brk(TFAIL, "Received unexpected UFFD_EVENT %d", msg.event);
+
+	if (!(msg.arg.pagefault.flags & UFFD_PAGEFAULT_FLAG_MINOR)) {
+		tst_brk(TBROK, "expected MINOR fault, got flags=0x%llx",
+			(unsigned long long)msg.arg.pagefault.flags);
+	}
+
+	/* Update the shmem page in page cache before resuming the fault. */
+	SAFE_PWRITE(1, memfd, &z, 1, 0);
+
+	uffdio_continue.range.start =
+		msg.arg.pagefault.address & ~((unsigned long)page_size - 1);
+	uffdio_continue.range.len = page_size;
+
+	SAFE_IOCTL(uffd, UFFDIO_CONTINUE, &uffdio_continue);
+
+	SAFE_CLOSE(uffd);
+	return NULL;
+}
+
+static void run(void)
+{
+	pthread_t thr;
+	struct uffdio_api uffdio_api = {};
+	struct uffdio_register uffdio_register;
+
+	set_pages();
+
+	uffd = SAFE_USERFAULTFD(O_CLOEXEC | O_NONBLOCK, true);
+
+	uffdio_api.api = UFFD_API;
+	uffdio_api.features = UFFD_FEATURE_MINOR_SHMEM;
+
+	SAFE_IOCTL(uffd, UFFDIO_API, &uffdio_api);
+
+	if (!(uffdio_api.features & UFFD_FEATURE_MINOR_SHMEM))
+		tst_brk(TCONF, "UFFD_FEATURE_MINOR_SHMEM not supported");
+
+	uffdio_register.range.start = (unsigned long) page;
+	uffdio_register.range.len = page_size;
+	uffdio_register.mode = UFFDIO_REGISTER_MODE_MINOR;
+
+	SAFE_IOCTL(uffd, UFFDIO_REGISTER, &uffdio_register);
+
+	/*
+	 * Drop PTEs while retaining the cached shmem page so the next access
+	 * faults in MINOR mode.
+	 */
+	if (madvise(page, page_size, MADV_DONTNEED) < 0)
+		tst_brk(TBROK | TERRNO, "madvise MADV_DONTNEED failed");
+
+	SAFE_PTHREAD_CREATE(&thr, NULL, (void *) handle_thread, NULL);
+
+	char c = page[0];
+
+	if (c == 'Z')
+		tst_res(TPASS, "Pagefault handled via UFFDIO_CONTINUE");
+	else
+		tst_res(TFAIL, "pagefault not handled via UFFDIO_CONTINUE, got '%c'", c);
+
+	SAFE_PTHREAD_JOIN(thr, NULL);
+	reset_pages();
+}
+
+static struct tst_test test = {
+	.test_all = run,
+	/*
+	 * UFFDIO_CONTINUE is available since 5.13 but
+	 * UFFD_FEATURE_MINOR_SHMEM appeared in 5.14
+	 */
+	.min_kver = "5.14",
+	.cleanup = reset_pages,
+};
-- 
2.53.0


-- 
Mailing list info: https://lists.linux.it/listinfo/ltp

[LTP] [PATCH v4 1/2] memfd_create: move sys_memfd_create() to lapi/memfd.h

[Ricardo Branco]

Add the static inline wrapper to include/lapi/memfd.h and include the
required headers so other tests can reuse it.

Also fix some minor issues detected by make check.

Signed-off-by: Ricardo Branco <rbranco@suse.de>
---
 include/lapi/memfd.h                                      | 8 ++++++++
 testcases/kernel/syscalls/memfd_create/memfd_create01.c   | 1 -
 .../kernel/syscalls/memfd_create/memfd_create_common.c    | 5 -----
 .../kernel/syscalls/memfd_create/memfd_create_common.h    | 2 +-
 4 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/include/lapi/memfd.h b/include/lapi/memfd.h
index 57b6cd83d..46ccb0a3f 100644
--- a/include/lapi/memfd.h
+++ b/include/lapi/memfd.h
@@ -6,6 +6,9 @@
 #ifndef LAPI_MEMFD_H__
 #define LAPI_MEMFD_H__
 
+#include "tst_test.h"
+#include "lapi/syscalls.h"
+
 /* flags for memfd_create(2) (unsigned int) */
 #ifndef MFD_CLOEXEC
 # define MFD_CLOEXEC             0x0001U
@@ -47,4 +50,9 @@
 #define MFD_HUGE_16GB (34 << 26)
 #endif
 
+static inline int sys_memfd_create(const char *name, unsigned int flags)
+{
+	return tst_syscall(__NR_memfd_create, name, flags);
+}
+
 #endif /* LAPI_MEMFD_H__ */
diff --git a/testcases/kernel/syscalls/memfd_create/memfd_create01.c b/testcases/kernel/syscalls/memfd_create/memfd_create01.c
index 73f6b01e8..28ad04a86 100644
--- a/testcases/kernel/syscalls/memfd_create/memfd_create01.c
+++ b/testcases/kernel/syscalls/memfd_create/memfd_create01.c
@@ -212,7 +212,6 @@ static void test_share_open(int fd)
 	SAFE_CLOSE(fd2);
 }
 
-
 static const struct tcase {
 	int flags;
 	void (*func)(int fd);
diff --git a/testcases/kernel/syscalls/memfd_create/memfd_create_common.c b/testcases/kernel/syscalls/memfd_create/memfd_create_common.c
index a52b02a56..63e8daac5 100644
--- a/testcases/kernel/syscalls/memfd_create/memfd_create_common.c
+++ b/testcases/kernel/syscalls/memfd_create/memfd_create_common.c
@@ -24,11 +24,6 @@
 
 #include "memfd_create_common.h"
 
-int sys_memfd_create(const char *name, unsigned int flags)
-{
-	return tst_syscall(__NR_memfd_create, name, flags);
-}
-
 int check_fallocate(const char *filename, const int lineno, int fd,
 			int mode, off_t offset, off_t len)
 {
diff --git a/testcases/kernel/syscalls/memfd_create/memfd_create_common.h b/testcases/kernel/syscalls/memfd_create/memfd_create_common.h
index 60ad895fe..8e5a3efbd 100644
--- a/testcases/kernel/syscalls/memfd_create/memfd_create_common.h
+++ b/testcases/kernel/syscalls/memfd_create/memfd_create_common.h
@@ -50,7 +50,7 @@
 	check_munmap(__FILE__, __LINE__, (p), (length))
 
 #define CHECK_MFD_HAS_SEALS(fd, seals) \
-	check_mfd_has_seals(__FILE__, __LINE__, (fd), (seals));
+	check_mfd_has_seals(__FILE__, __LINE__, (fd), (seals))
 
 #define CHECK_MFD_ADD_SEALS(fd, seals) \
 	({int r = SAFE_FCNTL((fd), F_ADD_SEALS, (seals)); \
-- 
2.53.0


-- 
Mailing list info: https://lists.linux.it/listinfo/ltp

[LTP] [PATCH v4 2/2] userfaultfd: Add new test using UFFDIO_CONTINUE

[Ricardo Branco]

Add test to exercise UFFDIO_CONTINUE on a shared-memory mapping with
UFFD_PAGEFAULT_FLAG_MINOR. The test populates a memfd-backed page,
drops only the PTEs with MADV_DONTNEED, verifies that the resulting
fault is reported as MINOR, updates the page cache from the handler
thread, and resumes execution with UFFDIO_CONTINUE.

Signed-off-by: Ricardo Branco <rbranco@suse.de>
---
 include/lapi/userfaultfd.h                    |   1 +
 runtest/syscalls                              |   1 +
 .../kernel/syscalls/userfaultfd/.gitignore    |   1 +
 .../kernel/syscalls/userfaultfd/Makefile      |   1 +
 .../syscalls/userfaultfd/userfaultfd07.c      | 152 ++++++++++++++++++
 5 files changed, 156 insertions(+)
 create mode 100644 testcases/kernel/syscalls/userfaultfd/userfaultfd07.c

diff --git a/include/lapi/userfaultfd.h b/include/lapi/userfaultfd.h
index aab3890b7..c05b8dbf5 100644
--- a/include/lapi/userfaultfd.h
+++ b/include/lapi/userfaultfd.h
@@ -171,6 +171,7 @@ struct uffdio_zeropage {
 #ifndef UFFD_PAGEFAULT_FLAG_MINOR
 #define UFFD_FEATURE_MINOR_HUGETLBFS		(1<<9)
 #define UFFDIO_REGISTER_MODE_MINOR	((__u64)1<<2)
+#define UFFD_PAGEFAULT_FLAG_MINOR	(1<<2)
 
 #define _UFFDIO_CONTINUE		(0x07)
 #define UFFDIO_CONTINUE		_IOWR(UFFDIO, _UFFDIO_CONTINUE,	\
diff --git a/runtest/syscalls b/runtest/syscalls
index 6ba0227a8..534140f42 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls
@@ -1780,6 +1780,7 @@ userfaultfd03 userfaultfd03
 userfaultfd04 userfaultfd04
 userfaultfd05 userfaultfd05
 userfaultfd06 userfaultfd06
+userfaultfd07 userfaultfd07
 
 ustat01 ustat01
 ustat02 ustat02
diff --git a/testcases/kernel/syscalls/userfaultfd/.gitignore b/testcases/kernel/syscalls/userfaultfd/.gitignore
index bc32fdf3b..3478a162e 100644
--- a/testcases/kernel/syscalls/userfaultfd/.gitignore
+++ b/testcases/kernel/syscalls/userfaultfd/.gitignore
@@ -4,3 +4,4 @@
 /userfaultfd04
 /userfaultfd05
 /userfaultfd06
+/userfaultfd07
diff --git a/testcases/kernel/syscalls/userfaultfd/Makefile b/testcases/kernel/syscalls/userfaultfd/Makefile
index 3252e47df..257249e88 100644
--- a/testcases/kernel/syscalls/userfaultfd/Makefile
+++ b/testcases/kernel/syscalls/userfaultfd/Makefile
@@ -17,3 +17,4 @@ userfaultfd03: CFLAGS += -pthread
 userfaultfd04: CFLAGS += -pthread
 userfaultfd05: CFLAGS += -pthread
 userfaultfd06: CFLAGS += -pthread
+userfaultfd07: CFLAGS += -pthread
diff --git a/testcases/kernel/syscalls/userfaultfd/userfaultfd07.c b/testcases/kernel/syscalls/userfaultfd/userfaultfd07.c
new file mode 100644
index 000000000..96b273262
--- /dev/null
+++ b/testcases/kernel/syscalls/userfaultfd/userfaultfd07.c
@@ -0,0 +1,152 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2026 SUSE LLC
+ * Author: Ricardo Branco <rbranco@suse.com>
+ */
+
+/*\
+ * Force a pagefault event and handle it using :manpage:`userfaultfd(2)`
+ * from a different thread testing UFFDIO_CONTINUE.
+ */
+
+#include "config.h"
+#include <poll.h>
+#include <unistd.h>
+#include "tst_test.h"
+#include "tst_safe_macros.h"
+#include "tst_safe_prw.h"
+#include "tst_safe_pthread.h"
+#include "lapi/memfd.h"
+#include "lapi/userfaultfd.h"
+#include "lapi/syscalls.h"
+
+static long page_size;
+static char *page;
+static int uffd = -1;
+static int memfd = -1;
+
+static void set_pages(void)
+{
+	char ch = 'A';
+
+	page_size = SAFE_SYSCONF(_SC_PAGE_SIZE);
+
+	memfd = sys_memfd_create("ltp-uffd-continue", MFD_CLOEXEC);
+	if (memfd < 0)
+		tst_brk(TBROK | TERRNO, "memfd_create failed");
+
+	SAFE_FTRUNCATE(memfd, page_size);
+
+	/*
+	 * Populate page cache so that after MADV_DONTNEED the next access
+	 * can generate a MINOR fault rather than a MISSING fault.
+	 */
+	SAFE_PWRITE(1, memfd, &ch, 1, 0);
+
+	page = SAFE_MMAP(NULL, page_size, PROT_READ, MAP_SHARED, memfd, 0);
+}
+
+static void reset_pages(void)
+{
+	if (page) {
+		SAFE_MUNMAP(page, page_size);
+		page = NULL;
+	}
+
+	if (memfd != -1)
+		SAFE_CLOSE(memfd);
+
+	if (uffd != -1)
+		SAFE_CLOSE(uffd);
+}
+
+static void *handle_thread(void *arg LTP_ATTRIBUTE_UNUSED)
+{
+	static struct uffd_msg msg;
+	struct uffdio_continue uffdio_continue = {};
+	struct pollfd pollfd;
+	int nready;
+	char z = 'Z';
+
+	pollfd.fd = uffd;
+	pollfd.events = POLLIN;
+	nready = poll(&pollfd, 1, -1);
+	if (nready == -1)
+		tst_brk(TBROK | TERRNO, "Error on poll");
+
+	SAFE_READ(1, uffd, &msg, sizeof(msg));
+
+	if (msg.event != UFFD_EVENT_PAGEFAULT)
+		tst_brk(TFAIL, "Received unexpected UFFD_EVENT %d", msg.event);
+
+	if (!(msg.arg.pagefault.flags & UFFD_PAGEFAULT_FLAG_MINOR)) {
+		tst_brk(TBROK, "expected MINOR fault, got flags=0x%llx",
+			(unsigned long long)msg.arg.pagefault.flags);
+	}
+
+	/* Update the shmem page in page cache before resuming the fault. */
+	SAFE_PWRITE(1, memfd, &z, 1, 0);
+
+	uffdio_continue.range.start =
+		msg.arg.pagefault.address & ~((unsigned long)page_size - 1);
+	uffdio_continue.range.len = page_size;
+
+	SAFE_IOCTL(uffd, UFFDIO_CONTINUE, &uffdio_continue);
+
+	SAFE_CLOSE(uffd);
+	return NULL;
+}
+
+static void run(void)
+{
+	pthread_t thr;
+	struct uffdio_api uffdio_api = {};
+	struct uffdio_register uffdio_register;
+
+	set_pages();
+
+	uffd = SAFE_USERFAULTFD(O_CLOEXEC | O_NONBLOCK, true);
+
+	uffdio_api.api = UFFD_API;
+	uffdio_api.features = UFFD_FEATURE_MINOR_SHMEM;
+
+	SAFE_IOCTL(uffd, UFFDIO_API, &uffdio_api);
+
+	if (!(uffdio_api.features & UFFD_FEATURE_MINOR_SHMEM))
+		tst_brk(TCONF, "UFFD_FEATURE_MINOR_SHMEM not supported");
+
+	uffdio_register.range.start = (unsigned long) page;
+	uffdio_register.range.len = page_size;
+	uffdio_register.mode = UFFDIO_REGISTER_MODE_MINOR;
+
+	SAFE_IOCTL(uffd, UFFDIO_REGISTER, &uffdio_register);
+
+	/*
+	 * Drop PTEs while retaining the cached shmem page so the next access
+	 * faults in MINOR mode.
+	 */
+	if (madvise(page, page_size, MADV_DONTNEED) < 0)
+		tst_brk(TBROK | TERRNO, "madvise MADV_DONTNEED failed");
+
+	SAFE_PTHREAD_CREATE(&thr, NULL, (void *) handle_thread, NULL);
+
+	char c = page[0];
+
+	if (c == 'Z')
+		tst_res(TPASS, "Pagefault handled via UFFDIO_CONTINUE");
+	else
+		tst_res(TFAIL, "pagefault not handled via UFFDIO_CONTINUE, got '%c'", c);
+
+	SAFE_PTHREAD_JOIN(thr, NULL);
+	reset_pages();
+}
+
+static struct tst_test test = {
+	.test_all = run,
+	/*
+	 * UFFDIO_CONTINUE is available since 5.13 but
+	 * UFFD_FEATURE_MINOR_SHMEM appeared in 5.14
+	 */
+	.min_kver = "5.14",
+	.cleanup = reset_pages,
+};
-- 
2.53.0


-- 
Mailing list info: https://lists.linux.it/listinfo/ltp

Re: [LTP] [PATCH v4 2/2] userfaultfd: Add new test using UFFDIO_CONTINUE

[Andrea Cervesato via ltp]

Hi Ricardo,

there must be something wrong with the patches you sent. I see v4 (last one
was v2) and patch #2 in a set of 2 patches (but only one is available).

Can you send the correct verion please? I will set the v3 as broken because
LTP is not compiling with that one.

Regards,
--
Andrea Cervesato
SUSE QE Automation Engineer Linux
andrea.cervesato@suse.com

-- 
Mailing list info: https://lists.linux.it/listinfo/ltp

Re: [LTP] [PATCH v4 2/2] userfaultfd: Add new test using UFFDIO_CONTINUE

[Andrea Cervesato via ltp]

Hi,

sorry I was confused by the patchwork interface (sigh). All good, I will
review the v4.

--
Andrea Cervesato
SUSE QE Automation Engineer Linux
andrea.cervesato@suse.com

-- 
Mailing list info: https://lists.linux.it/listinfo/ltp

[LTP] [PATCH v5 1/2] memfd_create: move sys_memfd_create() to lapi/memfd.h

[Ricardo Branco]

Add the static inline wrapper to include/lapi/memfd.h and include the
required headers so other tests can reuse it.

Also fix some minor issues detected by make check.

Signed-off-by: Ricardo Branco <rbranco@suse.de>
---
 include/lapi/memfd.h                                      | 8 ++++++++
 testcases/kernel/syscalls/memfd_create/memfd_create01.c   | 1 -
 .../kernel/syscalls/memfd_create/memfd_create_common.c    | 5 -----
 .../kernel/syscalls/memfd_create/memfd_create_common.h    | 4 +---
 4 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/include/lapi/memfd.h b/include/lapi/memfd.h
index 57b6cd83d..46ccb0a3f 100644
--- a/include/lapi/memfd.h
+++ b/include/lapi/memfd.h
@@ -6,6 +6,9 @@
 #ifndef LAPI_MEMFD_H__
 #define LAPI_MEMFD_H__
 
+#include "tst_test.h"
+#include "lapi/syscalls.h"
+
 /* flags for memfd_create(2) (unsigned int) */
 #ifndef MFD_CLOEXEC
 # define MFD_CLOEXEC             0x0001U
@@ -47,4 +50,9 @@
 #define MFD_HUGE_16GB (34 << 26)
 #endif
 
+static inline int sys_memfd_create(const char *name, unsigned int flags)
+{
+	return tst_syscall(__NR_memfd_create, name, flags);
+}
+
 #endif /* LAPI_MEMFD_H__ */
diff --git a/testcases/kernel/syscalls/memfd_create/memfd_create01.c b/testcases/kernel/syscalls/memfd_create/memfd_create01.c
index 73f6b01e8..28ad04a86 100644
--- a/testcases/kernel/syscalls/memfd_create/memfd_create01.c
+++ b/testcases/kernel/syscalls/memfd_create/memfd_create01.c
@@ -212,7 +212,6 @@ static void test_share_open(int fd)
 	SAFE_CLOSE(fd2);
 }
 
-
 static const struct tcase {
 	int flags;
 	void (*func)(int fd);
diff --git a/testcases/kernel/syscalls/memfd_create/memfd_create_common.c b/testcases/kernel/syscalls/memfd_create/memfd_create_common.c
index a52b02a56..63e8daac5 100644
--- a/testcases/kernel/syscalls/memfd_create/memfd_create_common.c
+++ b/testcases/kernel/syscalls/memfd_create/memfd_create_common.c
@@ -24,11 +24,6 @@
 
 #include "memfd_create_common.h"
 
-int sys_memfd_create(const char *name, unsigned int flags)
-{
-	return tst_syscall(__NR_memfd_create, name, flags);
-}
-
 int check_fallocate(const char *filename, const int lineno, int fd,
 			int mode, off_t offset, off_t len)
 {
diff --git a/testcases/kernel/syscalls/memfd_create/memfd_create_common.h b/testcases/kernel/syscalls/memfd_create/memfd_create_common.h
index 60ad895fe..df809d6c7 100644
--- a/testcases/kernel/syscalls/memfd_create/memfd_create_common.h
+++ b/testcases/kernel/syscalls/memfd_create/memfd_create_common.h
@@ -50,7 +50,7 @@
 	check_munmap(__FILE__, __LINE__, (p), (length))
 
 #define CHECK_MFD_HAS_SEALS(fd, seals) \
-	check_mfd_has_seals(__FILE__, __LINE__, (fd), (seals));
+	check_mfd_has_seals(__FILE__, __LINE__, (fd), (seals))
 
 #define CHECK_MFD_ADD_SEALS(fd, seals) \
 	({int r = SAFE_FCNTL((fd), F_ADD_SEALS, (seals)); \
@@ -101,8 +101,6 @@ int mfd_flags_available(const char *filename, const int lineno,
 
 int get_mfd_all_available_flags(const char *filename, const int lineno);
 
-int sys_memfd_create(const char *name, unsigned int flags);
-
 int check_fallocate(const char *filename, const int lineno, int fd,
 			int mode, off_t offset, off_t len);
 int check_fallocate_fail(const char *filename, const int lineno, int fd,
-- 
2.53.0


-- 
Mailing list info: https://lists.linux.it/listinfo/ltp

[LTP] [PATCH v5 2/2] userfaultfd: Add new test using UFFDIO_CONTINUE

[Ricardo Branco]

Add test to exercise UFFDIO_CONTINUE on a shared-memory mapping with
UFFD_PAGEFAULT_FLAG_MINOR. The test populates a memfd-backed page,
drops only the PTEs with MADV_DONTNEED, verifies that the resulting
fault is reported as MINOR, updates the page cache from the handler
thread, and resumes execution with UFFDIO_CONTINUE.

Signed-off-by: Ricardo Branco <rbranco@suse.de>
---
 include/lapi/userfaultfd.h                    |   1 +
 runtest/syscalls                              |   1 +
 .../kernel/syscalls/userfaultfd/.gitignore    |   1 +
 .../kernel/syscalls/userfaultfd/Makefile      |   1 +
 .../syscalls/userfaultfd/userfaultfd07.c      | 152 ++++++++++++++++++
 5 files changed, 156 insertions(+)
 create mode 100644 testcases/kernel/syscalls/userfaultfd/userfaultfd07.c

diff --git a/include/lapi/userfaultfd.h b/include/lapi/userfaultfd.h
index aab3890b7..c05b8dbf5 100644
--- a/include/lapi/userfaultfd.h
+++ b/include/lapi/userfaultfd.h
@@ -171,6 +171,7 @@ struct uffdio_zeropage {
 #ifndef UFFD_PAGEFAULT_FLAG_MINOR
 #define UFFD_FEATURE_MINOR_HUGETLBFS		(1<<9)
 #define UFFDIO_REGISTER_MODE_MINOR	((__u64)1<<2)
+#define UFFD_PAGEFAULT_FLAG_MINOR	(1<<2)
 
 #define _UFFDIO_CONTINUE		(0x07)
 #define UFFDIO_CONTINUE		_IOWR(UFFDIO, _UFFDIO_CONTINUE,	\
diff --git a/runtest/syscalls b/runtest/syscalls
index 6ba0227a8..534140f42 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls
@@ -1780,6 +1780,7 @@ userfaultfd03 userfaultfd03
 userfaultfd04 userfaultfd04
 userfaultfd05 userfaultfd05
 userfaultfd06 userfaultfd06
+userfaultfd07 userfaultfd07
 
 ustat01 ustat01
 ustat02 ustat02
diff --git a/testcases/kernel/syscalls/userfaultfd/.gitignore b/testcases/kernel/syscalls/userfaultfd/.gitignore
index bc32fdf3b..3478a162e 100644
--- a/testcases/kernel/syscalls/userfaultfd/.gitignore
+++ b/testcases/kernel/syscalls/userfaultfd/.gitignore
@@ -4,3 +4,4 @@
 /userfaultfd04
 /userfaultfd05
 /userfaultfd06
+/userfaultfd07
diff --git a/testcases/kernel/syscalls/userfaultfd/Makefile b/testcases/kernel/syscalls/userfaultfd/Makefile
index 3252e47df..257249e88 100644
--- a/testcases/kernel/syscalls/userfaultfd/Makefile
+++ b/testcases/kernel/syscalls/userfaultfd/Makefile
@@ -17,3 +17,4 @@ userfaultfd03: CFLAGS += -pthread
 userfaultfd04: CFLAGS += -pthread
 userfaultfd05: CFLAGS += -pthread
 userfaultfd06: CFLAGS += -pthread
+userfaultfd07: CFLAGS += -pthread
diff --git a/testcases/kernel/syscalls/userfaultfd/userfaultfd07.c b/testcases/kernel/syscalls/userfaultfd/userfaultfd07.c
new file mode 100644
index 000000000..96b273262
--- /dev/null
+++ b/testcases/kernel/syscalls/userfaultfd/userfaultfd07.c
@@ -0,0 +1,152 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2026 SUSE LLC
+ * Author: Ricardo Branco <rbranco@suse.com>
+ */
+
+/*\
+ * Force a pagefault event and handle it using :manpage:`userfaultfd(2)`
+ * from a different thread testing UFFDIO_CONTINUE.
+ */
+
+#include "config.h"
+#include <poll.h>
+#include <unistd.h>
+#include "tst_test.h"
+#include "tst_safe_macros.h"
+#include "tst_safe_prw.h"
+#include "tst_safe_pthread.h"
+#include "lapi/memfd.h"
+#include "lapi/userfaultfd.h"
+#include "lapi/syscalls.h"
+
+static long page_size;
+static char *page;
+static int uffd = -1;
+static int memfd = -1;
+
+static void set_pages(void)
+{
+	char ch = 'A';
+
+	page_size = SAFE_SYSCONF(_SC_PAGE_SIZE);
+
+	memfd = sys_memfd_create("ltp-uffd-continue", MFD_CLOEXEC);
+	if (memfd < 0)
+		tst_brk(TBROK | TERRNO, "memfd_create failed");
+
+	SAFE_FTRUNCATE(memfd, page_size);
+
+	/*
+	 * Populate page cache so that after MADV_DONTNEED the next access
+	 * can generate a MINOR fault rather than a MISSING fault.
+	 */
+	SAFE_PWRITE(1, memfd, &ch, 1, 0);
+
+	page = SAFE_MMAP(NULL, page_size, PROT_READ, MAP_SHARED, memfd, 0);
+}
+
+static void reset_pages(void)
+{
+	if (page) {
+		SAFE_MUNMAP(page, page_size);
+		page = NULL;
+	}
+
+	if (memfd != -1)
+		SAFE_CLOSE(memfd);
+
+	if (uffd != -1)
+		SAFE_CLOSE(uffd);
+}
+
+static void *handle_thread(void *arg LTP_ATTRIBUTE_UNUSED)
+{
+	static struct uffd_msg msg;
+	struct uffdio_continue uffdio_continue = {};
+	struct pollfd pollfd;
+	int nready;
+	char z = 'Z';
+
+	pollfd.fd = uffd;
+	pollfd.events = POLLIN;
+	nready = poll(&pollfd, 1, -1);
+	if (nready == -1)
+		tst_brk(TBROK | TERRNO, "Error on poll");
+
+	SAFE_READ(1, uffd, &msg, sizeof(msg));
+
+	if (msg.event != UFFD_EVENT_PAGEFAULT)
+		tst_brk(TFAIL, "Received unexpected UFFD_EVENT %d", msg.event);
+
+	if (!(msg.arg.pagefault.flags & UFFD_PAGEFAULT_FLAG_MINOR)) {
+		tst_brk(TBROK, "expected MINOR fault, got flags=0x%llx",
+			(unsigned long long)msg.arg.pagefault.flags);
+	}
+
+	/* Update the shmem page in page cache before resuming the fault. */
+	SAFE_PWRITE(1, memfd, &z, 1, 0);
+
+	uffdio_continue.range.start =
+		msg.arg.pagefault.address & ~((unsigned long)page_size - 1);
+	uffdio_continue.range.len = page_size;
+
+	SAFE_IOCTL(uffd, UFFDIO_CONTINUE, &uffdio_continue);
+
+	SAFE_CLOSE(uffd);
+	return NULL;
+}
+
+static void run(void)
+{
+	pthread_t thr;
+	struct uffdio_api uffdio_api = {};
+	struct uffdio_register uffdio_register;
+
+	set_pages();
+
+	uffd = SAFE_USERFAULTFD(O_CLOEXEC | O_NONBLOCK, true);
+
+	uffdio_api.api = UFFD_API;
+	uffdio_api.features = UFFD_FEATURE_MINOR_SHMEM;
+
+	SAFE_IOCTL(uffd, UFFDIO_API, &uffdio_api);
+
+	if (!(uffdio_api.features & UFFD_FEATURE_MINOR_SHMEM))
+		tst_brk(TCONF, "UFFD_FEATURE_MINOR_SHMEM not supported");
+
+	uffdio_register.range.start = (unsigned long) page;
+	uffdio_register.range.len = page_size;
+	uffdio_register.mode = UFFDIO_REGISTER_MODE_MINOR;
+
+	SAFE_IOCTL(uffd, UFFDIO_REGISTER, &uffdio_register);
+
+	/*
+	 * Drop PTEs while retaining the cached shmem page so the next access
+	 * faults in MINOR mode.
+	 */
+	if (madvise(page, page_size, MADV_DONTNEED) < 0)
+		tst_brk(TBROK | TERRNO, "madvise MADV_DONTNEED failed");
+
+	SAFE_PTHREAD_CREATE(&thr, NULL, (void *) handle_thread, NULL);
+
+	char c = page[0];
+
+	if (c == 'Z')
+		tst_res(TPASS, "Pagefault handled via UFFDIO_CONTINUE");
+	else
+		tst_res(TFAIL, "pagefault not handled via UFFDIO_CONTINUE, got '%c'", c);
+
+	SAFE_PTHREAD_JOIN(thr, NULL);
+	reset_pages();
+}
+
+static struct tst_test test = {
+	.test_all = run,
+	/*
+	 * UFFDIO_CONTINUE is available since 5.13 but
+	 * UFFD_FEATURE_MINOR_SHMEM appeared in 5.14
+	 */
+	.min_kver = "5.14",
+	.cleanup = reset_pages,
+};
-- 
2.53.0


-- 
Mailing list info: https://lists.linux.it/listinfo/ltp