[PATCH v2 0/2] Make liveupdate selftests library

[PATCH v2 0/2] Make liveupdate selftests library

[Vipin Sharma]

Hello,


This is v2 series of refactoring liveupdate selftests as a library. It
exposes common liveupdate ioctls as a library which can be used by other
selftests like VFIO and IOMMU.

Currently, there are no users of this change but it is being used in
VFIO and iommu liveupdate series.

  https://lore.kernel.org/kvm/20260323235817.1960573-15-dmatlack@google.com/
  https://lore.kernel.org/linux-iommu/20260427175633.1978233-17-skhawaja@google.com/

I think it is better to move the patches out from the above series and
propose them as a separate series for inclusion in liveupdate repo. That
way we can decouple multiple downstream dependencies and then it can be
used by VFIO, IOMMU, and KVM (guest_memfd preservation) separately.

v2:
 - Addressed Sashiko feedback regarding folder creation.
   https://sashiko.dev/#/patchset/20260511201155.1488670-1-vipinsh%40google.com
 - Update liveupdate.c test to use ioctl wrappers in library

v1: https://lore.kernel.org/all/20260511201155.1488670-1-vipinsh@google.com/
Vipin Sharma (2):
  selftests/liveupdate: Move luo_test_utils.* into a reusable library
  selftests/liveupdate: Add helpers to preserve/retrieve FDs

 tools/testing/selftests/liveupdate/.gitignore |  1 +
 tools/testing/selftests/liveupdate/Makefile   | 14 ++----
 .../include/libliveupdate.h}                  | 10 +++--
 .../selftests/liveupdate/lib/libliveupdate.mk | 20 +++++++++
 .../{luo_test_utils.c => lib/liveupdate.c}    | 43 ++++++++++++++-----
 .../testing/selftests/liveupdate/liveupdate.c | 40 ++++++-----------
 .../selftests/liveupdate/luo_kexec_simple.c   |  2 +-
 .../selftests/liveupdate/luo_multi_session.c  |  2 +-
 .../selftests/liveupdate/luo_stress_files.c   |  2 +-
 .../liveupdate/luo_stress_sessions.c          |  2 +-
 10 files changed, 81 insertions(+), 55 deletions(-)
 rename tools/testing/selftests/liveupdate/{luo_test_utils.h => lib/include/libliveupdate.h} (80%)
 create mode 100644 tools/testing/selftests/liveupdate/lib/libliveupdate.mk
 rename tools/testing/selftests/liveupdate/{luo_test_utils.c => lib/liveupdate.c} (91%)


base-commit: 3a358c78093f98a70d84c934b7054f636bc846f2
-- 
2.54.0.1099.g489fc7bff1-goog

[PATCH v2 1/2] selftests/liveupdate: Move luo_test_utils.* into a reusable library

[Vipin Sharma]

Move luo_test_utils.[ch] into a lib/ directory and pull the rules to
build them out into a separate make script. This will enable these
utilities to be also built by and used within other selftests (such as
VFIO).

No functional change intended.

Co-developed-by: David Matlack <dmatlack@google.com>
Signed-off-by: David Matlack <dmatlack@google.com>
Acked-by: Pratyush Yadav (Google) <pratyush@kernel.org>
Signed-off-by: Vipin Sharma <vipinsh@google.com>
---
 tools/testing/selftests/liveupdate/.gitignore |  1 +
 tools/testing/selftests/liveupdate/Makefile   | 14 ++++---------
 .../include/libliveupdate.h}                  |  8 ++++----
 .../selftests/liveupdate/lib/libliveupdate.mk | 20 +++++++++++++++++++
 .../{luo_test_utils.c => lib/liveupdate.c}    |  2 +-
 .../testing/selftests/liveupdate/liveupdate.c |  2 +-
 .../selftests/liveupdate/luo_kexec_simple.c   |  2 +-
 .../selftests/liveupdate/luo_multi_session.c  |  2 +-
 .../selftests/liveupdate/luo_stress_files.c   |  2 +-
 .../liveupdate/luo_stress_sessions.c          |  2 +-
 10 files changed, 35 insertions(+), 20 deletions(-)
 rename tools/testing/selftests/liveupdate/{luo_test_utils.h => lib/include/libliveupdate.h} (87%)
 create mode 100644 tools/testing/selftests/liveupdate/lib/libliveupdate.mk
 rename tools/testing/selftests/liveupdate/{luo_test_utils.c => lib/liveupdate.c} (99%)

diff --git a/tools/testing/selftests/liveupdate/.gitignore b/tools/testing/selftests/liveupdate/.gitignore
index 661827083ab6..18a0c7036cf3 100644
--- a/tools/testing/selftests/liveupdate/.gitignore
+++ b/tools/testing/selftests/liveupdate/.gitignore
@@ -3,6 +3,7 @@
 !/**/
 !*.c
 !*.h
+!*.mk
 !*.sh
 !.gitignore
 !config
diff --git a/tools/testing/selftests/liveupdate/Makefile b/tools/testing/selftests/liveupdate/Makefile
index 30689d22cb02..634211c66652 100644
--- a/tools/testing/selftests/liveupdate/Makefile
+++ b/tools/testing/selftests/liveupdate/Makefile
@@ -1,7 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0-only
 
-LIB_C += luo_test_utils.c
-
 TEST_GEN_PROGS += liveupdate
 
 TEST_GEN_PROGS_EXTENDED += luo_kexec_simple
@@ -12,25 +10,21 @@ TEST_GEN_PROGS_EXTENDED += luo_stress_files
 TEST_FILES += do_kexec.sh
 
 include ../lib.mk
+include lib/libliveupdate.mk
 
 CFLAGS += $(KHDR_INCLUDES)
 CFLAGS += -Wall -O2 -Wno-unused-function
 CFLAGS += -MD
 
-LIB_O := $(patsubst %.c, $(OUTPUT)/%.o, $(LIB_C))
 TEST_O := $(patsubst %, %.o, $(TEST_GEN_PROGS))
 TEST_O += $(patsubst %, %.o, $(TEST_GEN_PROGS_EXTENDED))
 
-TEST_DEP_FILES := $(patsubst %.o, %.d, $(LIB_O))
+TEST_DEP_FILES := $(patsubst %.o, %.d, $(LIBLIVEUPDATE_O))
 TEST_DEP_FILES += $(patsubst %.o, %.d, $(TEST_O))
 -include $(TEST_DEP_FILES)
 
-$(LIB_O): $(OUTPUT)/%.o: %.c
-	$(CC) $(CFLAGS) $(CPPFLAGS) $(TARGET_ARCH) -c $< -o $@
-
-$(TEST_GEN_PROGS) $(TEST_GEN_PROGS_EXTENDED): $(OUTPUT)/%: %.o $(LIB_O)
-	$(CC) $(CFLAGS) $(CPPFLAGS) $(LDFLAGS) $(TARGET_ARCH) $< $(LIB_O) $(LDLIBS) -o $@
+$(TEST_GEN_PROGS) $(TEST_GEN_PROGS_EXTENDED): $(OUTPUT)/%: %.o $(LIBLIVEUPDATE_O)
+	$(CC) $(CFLAGS) $(CPPFLAGS) $(LDFLAGS) $(TARGET_ARCH) $< $(LIBLIVEUPDATE_O) $(LDLIBS) -o $@
 
-EXTRA_CLEAN += $(LIB_O)
 EXTRA_CLEAN += $(TEST_O)
 EXTRA_CLEAN += $(TEST_DEP_FILES)
diff --git a/tools/testing/selftests/liveupdate/luo_test_utils.h b/tools/testing/selftests/liveupdate/lib/include/libliveupdate.h
similarity index 87%
rename from tools/testing/selftests/liveupdate/luo_test_utils.h
rename to tools/testing/selftests/liveupdate/lib/include/libliveupdate.h
index 6a0d85386613..6ff71d7c3d9c 100644
--- a/tools/testing/selftests/liveupdate/luo_test_utils.h
+++ b/tools/testing/selftests/liveupdate/lib/include/libliveupdate.h
@@ -7,13 +7,13 @@
  * Utility functions for LUO kselftests.
  */
 
-#ifndef LUO_TEST_UTILS_H
-#define LUO_TEST_UTILS_H
+#ifndef SELFTESTS_LIVEUPDATE_LIB_LIVEUPDATE_H
+#define SELFTESTS_LIVEUPDATE_LIB_LIVEUPDATE_H
 
 #include <errno.h>
 #include <string.h>
 #include <linux/liveupdate.h>
-#include "../kselftest.h"
+#include "../../../kselftest.h"
 
 #define LUO_DEVICE "/dev/liveupdate"
 
@@ -43,4 +43,4 @@ typedef void (*luo_test_stage2_fn)(int luo_fd, int state_session_fd);
 int luo_test(int argc, char *argv[], const char *state_session_name,
 	     luo_test_stage1_fn stage1, luo_test_stage2_fn stage2);
 
-#endif /* LUO_TEST_UTILS_H */
+#endif /* SELFTESTS_LIVEUPDATE_LIB_LIVEUPDATE_H */
diff --git a/tools/testing/selftests/liveupdate/lib/libliveupdate.mk b/tools/testing/selftests/liveupdate/lib/libliveupdate.mk
new file mode 100644
index 000000000000..0fb738c02330
--- /dev/null
+++ b/tools/testing/selftests/liveupdate/lib/libliveupdate.mk
@@ -0,0 +1,20 @@
+include $(top_srcdir)/scripts/subarch.include
+ARCH ?= $(SUBARCH)
+
+LIBLIVEUPDATE_SRCDIR := $(selfdir)/liveupdate/lib
+
+LIBLIVEUPDATE_C := liveupdate.c
+
+LIBLIVEUPDATE_OUTPUT := $(OUTPUT)/libliveupdate
+
+LIBLIVEUPDATE_O := $(patsubst %.c, $(LIBLIVEUPDATE_OUTPUT)/%.o, $(LIBLIVEUPDATE_C))
+
+CFLAGS += -I$(LIBLIVEUPDATE_SRCDIR)/include
+
+$(LIBLIVEUPDATE_OUTPUT):
+	$(Q)mkdir -p $@
+
+$(LIBLIVEUPDATE_O): $(LIBLIVEUPDATE_OUTPUT)/%.o : $(LIBLIVEUPDATE_SRCDIR)/%.c | $(LIBLIVEUPDATE_OUTPUT)
+	$(CC) $(CFLAGS) $(CPPFLAGS) $(TARGET_ARCH) -c $< -o $@
+
+EXTRA_CLEAN += $(LIBLIVEUPDATE_OUTPUT)
diff --git a/tools/testing/selftests/liveupdate/luo_test_utils.c b/tools/testing/selftests/liveupdate/lib/liveupdate.c
similarity index 99%
rename from tools/testing/selftests/liveupdate/luo_test_utils.c
rename to tools/testing/selftests/liveupdate/lib/liveupdate.c
index 333a3530051b..897c200f3845 100644
--- a/tools/testing/selftests/liveupdate/luo_test_utils.c
+++ b/tools/testing/selftests/liveupdate/lib/liveupdate.c
@@ -22,7 +22,7 @@
 #include <errno.h>
 #include <stdarg.h>
 
-#include "luo_test_utils.h"
+#include <libliveupdate.h>
 
 int luo_open_device(void)
 {
diff --git a/tools/testing/selftests/liveupdate/liveupdate.c b/tools/testing/selftests/liveupdate/liveupdate.c
index 502fb3567e38..6bfd4e53528c 100644
--- a/tools/testing/selftests/liveupdate/liveupdate.c
+++ b/tools/testing/selftests/liveupdate/liveupdate.c
@@ -25,8 +25,8 @@
 #include <unistd.h>
 
 #include <linux/liveupdate.h>
+#include <libliveupdate.h>
 
-#include "luo_test_utils.h"
 #include "../kselftest.h"
 #include "../kselftest_harness.h"
 
diff --git a/tools/testing/selftests/liveupdate/luo_kexec_simple.c b/tools/testing/selftests/liveupdate/luo_kexec_simple.c
index d7ac1f3dc4cb..786ac93b9ae3 100644
--- a/tools/testing/selftests/liveupdate/luo_kexec_simple.c
+++ b/tools/testing/selftests/liveupdate/luo_kexec_simple.c
@@ -8,7 +8,7 @@
  * across a single kexec reboot.
  */
 
-#include "luo_test_utils.h"
+#include <libliveupdate.h>
 
 #define TEST_SESSION_NAME "test-session"
 #define TEST_MEMFD_TOKEN 0x1A
diff --git a/tools/testing/selftests/liveupdate/luo_multi_session.c b/tools/testing/selftests/liveupdate/luo_multi_session.c
index 0ee2d795beef..aac24a5f5ce3 100644
--- a/tools/testing/selftests/liveupdate/luo_multi_session.c
+++ b/tools/testing/selftests/liveupdate/luo_multi_session.c
@@ -9,7 +9,7 @@
  * files.
  */
 
-#include "luo_test_utils.h"
+#include <libliveupdate.h>
 
 #define SESSION_EMPTY_1 "multi-test-empty-1"
 #define SESSION_EMPTY_2 "multi-test-empty-2"
diff --git a/tools/testing/selftests/liveupdate/luo_stress_files.c b/tools/testing/selftests/liveupdate/luo_stress_files.c
index 0cdf9cd4bac7..c0f15c892950 100644
--- a/tools/testing/selftests/liveupdate/luo_stress_files.c
+++ b/tools/testing/selftests/liveupdate/luo_stress_files.c
@@ -10,7 +10,7 @@
 
 #include <stdio.h>
 #include <unistd.h>
-#include "luo_test_utils.h"
+#include <libliveupdate.h>
 
 #define NUM_FILES 500
 #define STATE_SESSION_NAME "kexec_many_files_state"
diff --git a/tools/testing/selftests/liveupdate/luo_stress_sessions.c b/tools/testing/selftests/liveupdate/luo_stress_sessions.c
index f201b1839d1d..8af19259ced3 100644
--- a/tools/testing/selftests/liveupdate/luo_stress_sessions.c
+++ b/tools/testing/selftests/liveupdate/luo_stress_sessions.c
@@ -10,7 +10,7 @@
 
 #include <stdio.h>
 #include <unistd.h>
-#include "luo_test_utils.h"
+#include <libliveupdate.h>
 
 #define NUM_SESSIONS 2000
 #define STATE_SESSION_NAME "kexec_many_state"
-- 
2.54.0.1099.g489fc7bff1-goog

[PATCH v2 2/2] selftests/liveupdate: Add helpers to preserve/retrieve FDs

[Vipin Sharma]

Add helper functions to preserve and retrieve file descriptors from an
LUO session. This allows library users to work with FD preservation.

Now that there are helpers, use them instead of direct ioctl calls
in liveupdate.c

No functional change intended.

Co-developed-by: David Matlack <dmatlack@google.com>
Signed-off-by: David Matlack <dmatlack@google.com>
Signed-off-by: Vipin Sharma <vipinsh@google.com>
---
 .../liveupdate/lib/include/libliveupdate.h    |  2 +
 .../selftests/liveupdate/lib/liveupdate.c     | 41 +++++++++++++++----
 .../testing/selftests/liveupdate/liveupdate.c | 38 ++++++-----------
 3 files changed, 46 insertions(+), 35 deletions(-)

diff --git a/tools/testing/selftests/liveupdate/lib/include/libliveupdate.h b/tools/testing/selftests/liveupdate/lib/include/libliveupdate.h
index 6ff71d7c3d9c..2c6a6f6a2733 100644
--- a/tools/testing/selftests/liveupdate/lib/include/libliveupdate.h
+++ b/tools/testing/selftests/liveupdate/lib/include/libliveupdate.h
@@ -27,6 +27,8 @@ int luo_retrieve_session(int luo_fd, const char *name);
 int luo_session_finish(int session_fd);
 
 int luo_ensure_nofile_limit(long min_limit);
+int luo_session_preserve_fd(int session_fd, int fd, __u64 token);
+int luo_session_retrieve_fd(int session_fd, __u64 token);
 
 int create_and_preserve_memfd(int session_fd, int token, const char *data);
 int restore_and_verify_memfd(int session_fd, int token, const char *expected_data);
diff --git a/tools/testing/selftests/liveupdate/lib/liveupdate.c b/tools/testing/selftests/liveupdate/lib/liveupdate.c
index 897c200f3845..961a732b541d 100644
--- a/tools/testing/selftests/liveupdate/lib/liveupdate.c
+++ b/tools/testing/selftests/liveupdate/lib/liveupdate.c
@@ -78,9 +78,35 @@ int luo_retrieve_session(int luo_fd, const char *name)
 	return arg.fd;
 }
 
+int luo_session_preserve_fd(int session_fd, int fd, __u64 token)
+{
+	struct liveupdate_session_preserve_fd arg = {
+		.size = sizeof(arg),
+		.fd = fd,
+		.token = token,
+	};
+
+	if (ioctl(session_fd, LIVEUPDATE_SESSION_PRESERVE_FD, &arg) < 0)
+		return -errno;
+
+	return 0;
+}
+
+int luo_session_retrieve_fd(int session_fd, __u64 token)
+{
+	struct liveupdate_session_retrieve_fd arg = {
+		.size = sizeof(arg),
+		.token = token,
+	};
+
+	if (ioctl(session_fd, LIVEUPDATE_SESSION_RETRIEVE_FD, &arg) < 0)
+		return -errno;
+
+	return arg.fd;
+}
+
 int create_and_preserve_memfd(int session_fd, int token, const char *data)
 {
-	struct liveupdate_session_preserve_fd arg = { .size = sizeof(arg) };
 	long page_size = sysconf(_SC_PAGE_SIZE);
 	void *map = MAP_FAILED;
 	int mfd = -1, ret = -1;
@@ -99,9 +125,8 @@ int create_and_preserve_memfd(int session_fd, int token, const char *data)
 	snprintf(map, page_size, "%s", data);
 	munmap(map, page_size);
 
-	arg.fd = mfd;
-	arg.token = token;
-	if (ioctl(session_fd, LIVEUPDATE_SESSION_PRESERVE_FD, &arg) < 0)
+	ret = luo_session_preserve_fd(session_fd, mfd, token);
+	if (ret)
 		goto out;
 
 	ret = 0;
@@ -116,15 +141,13 @@ int create_and_preserve_memfd(int session_fd, int token, const char *data)
 int restore_and_verify_memfd(int session_fd, int token,
 			     const char *expected_data)
 {
-	struct liveupdate_session_retrieve_fd arg = { .size = sizeof(arg) };
 	long page_size = sysconf(_SC_PAGE_SIZE);
 	void *map = MAP_FAILED;
 	int mfd = -1, ret = -1;
 
-	arg.token = token;
-	if (ioctl(session_fd, LIVEUPDATE_SESSION_RETRIEVE_FD, &arg) < 0)
-		return -errno;
-	mfd = arg.fd;
+	mfd = luo_session_retrieve_fd(session_fd, token);
+	if (mfd < 0)
+		return mfd;
 
 	map = mmap(NULL, page_size, PROT_READ, MAP_SHARED, mfd, 0);
 	if (map == MAP_FAILED)
diff --git a/tools/testing/selftests/liveupdate/liveupdate.c b/tools/testing/selftests/liveupdate/liveupdate.c
index 6bfd4e53528c..e17a13136330 100644
--- a/tools/testing/selftests/liveupdate/liveupdate.c
+++ b/tools/testing/selftests/liveupdate/liveupdate.c
@@ -170,20 +170,6 @@ TEST_F(liveupdate_device, create_distinct_sessions)
 	ASSERT_EQ(close(session_fd2), 0);
 }
 
-static int preserve_fd(int session_fd, int fd_to_preserve, __u64 token)
-{
-	struct liveupdate_session_preserve_fd args = {};
-
-	args.size = sizeof(args);
-	args.fd = fd_to_preserve;
-	args.token = token;
-
-	if (ioctl(session_fd, LIVEUPDATE_SESSION_PRESERVE_FD, &args))
-		return -errno;
-
-	return 0;
-}
-
 /*
  * Test Case: Preserve MemFD
  *
@@ -208,7 +194,7 @@ TEST_F(liveupdate_device, preserve_memfd)
 	ASSERT_GE(mem_fd, 0);
 
 	ASSERT_EQ(write(mem_fd, test_str, strlen(test_str)), strlen(test_str));
-	ASSERT_EQ(preserve_fd(session_fd, mem_fd, 0x1234), 0);
+	ASSERT_EQ(luo_session_preserve_fd(session_fd, mem_fd, 0x1234), 0);
 	ASSERT_EQ(close(session_fd), 0);
 
 	ASSERT_EQ(lseek(mem_fd, 0, SEEK_SET), 0);
@@ -247,8 +233,8 @@ TEST_F(liveupdate_device, preserve_multiple_memfds)
 	ASSERT_EQ(write(mem_fd1, test_str1, strlen(test_str1)), strlen(test_str1));
 	ASSERT_EQ(write(mem_fd2, test_str2, strlen(test_str2)), strlen(test_str2));
 
-	ASSERT_EQ(preserve_fd(session_fd, mem_fd1, 0xAAAA), 0);
-	ASSERT_EQ(preserve_fd(session_fd, mem_fd2, 0xBBBB), 0);
+	ASSERT_EQ(luo_session_preserve_fd(session_fd, mem_fd1, 0xAAAA), 0);
+	ASSERT_EQ(luo_session_preserve_fd(session_fd, mem_fd2, 0xBBBB), 0);
 
 	memset(read_buf, 0, sizeof(read_buf));
 	ASSERT_EQ(lseek(mem_fd1, 0, SEEK_SET), 0);
@@ -303,10 +289,10 @@ TEST_F(liveupdate_device, preserve_complex_scenario)
 	mem_fd_empty2 = memfd_create("empty2", 0);
 	ASSERT_GE(mem_fd_empty2, 0);
 
-	ASSERT_EQ(preserve_fd(session_fd1, mem_fd_data1, 0x1111), 0);
-	ASSERT_EQ(preserve_fd(session_fd1, mem_fd_empty1, 0x2222), 0);
-	ASSERT_EQ(preserve_fd(session_fd2, mem_fd_data2, 0x3333), 0);
-	ASSERT_EQ(preserve_fd(session_fd2, mem_fd_empty2, 0x4444), 0);
+	ASSERT_EQ(luo_session_preserve_fd(session_fd1, mem_fd_data1, 0x1111), 0);
+	ASSERT_EQ(luo_session_preserve_fd(session_fd1, mem_fd_empty1, 0x2222), 0);
+	ASSERT_EQ(luo_session_preserve_fd(session_fd2, mem_fd_data2, 0x3333), 0);
+	ASSERT_EQ(luo_session_preserve_fd(session_fd2, mem_fd_empty2, 0x4444), 0);
 
 	ASSERT_EQ(lseek(mem_fd_data1, 0, SEEK_SET), 0);
 	ASSERT_EQ(read(mem_fd_data1, read_buf, sizeof(read_buf)), strlen(data1));
@@ -355,7 +341,7 @@ TEST_F(liveupdate_device, preserve_unsupported_fd)
 	unsupported_fd = open("/dev/null", O_RDWR);
 	ASSERT_GE(unsupported_fd, 0);
 
-	ret = preserve_fd(session_fd, unsupported_fd, 0xDEAD);
+	ret = luo_session_preserve_fd(session_fd, unsupported_fd, 0xDEAD);
 	EXPECT_EQ(ret, -ENOENT);
 
 	ASSERT_EQ(close(unsupported_fd), 0);
@@ -388,14 +374,14 @@ TEST_F(liveupdate_device, prevent_double_preservation)
 	ASSERT_GE(mem_fd, 0);
 
 	/* First preservation should succeed */
-	ASSERT_EQ(preserve_fd(session_fd1, mem_fd, 0x1111), 0);
+	ASSERT_EQ(luo_session_preserve_fd(session_fd1, mem_fd, 0x1111), 0);
 
 	/* Second preservation in a different session should fail with EBUSY */
-	ret = preserve_fd(session_fd2, mem_fd, 0x2222);
+	ret = luo_session_preserve_fd(session_fd2, mem_fd, 0x2222);
 	EXPECT_EQ(ret, -EBUSY);
 
 	/* Second preservation in the same session (different token) should fail with EBUSY */
-	ret = preserve_fd(session_fd1, mem_fd, 0x3333);
+	ret = luo_session_preserve_fd(session_fd1, mem_fd, 0x3333);
 	EXPECT_EQ(ret, -EBUSY);
 
 	ASSERT_EQ(close(mem_fd), 0);
@@ -565,7 +551,7 @@ TEST_F(liveupdate_device, preserve_many_files)
 	for (i = 0; i < MANY_FILES; i++) {
 		mem_fds[i] = memfd_create("test-memfd", 0);
 		ASSERT_GE(mem_fds[i], 0);
-		ASSERT_EQ(preserve_fd(session_fd, mem_fds[i], i), 0);
+		ASSERT_EQ(luo_session_preserve_fd(session_fd, mem_fds[i], i), 0);
 	}
 
 	for (i = 0; i < MANY_FILES; i++)
-- 
2.54.0.1099.g489fc7bff1-goog

Re: [PATCH v2 2/2] selftests/liveupdate: Add helpers to preserve/retrieve FDs

[Pratyush Yadav]

On Wed, Jun 10 2026, Vipin Sharma wrote:

> Add helper functions to preserve and retrieve file descriptors from an
> LUO session. This allows library users to work with FD preservation.
>
> Now that there are helpers, use them instead of direct ioctl calls
> in liveupdate.c
>
> No functional change intended.
>
> Co-developed-by: David Matlack <dmatlack@google.com>
> Signed-off-by: David Matlack <dmatlack@google.com>
> Signed-off-by: Vipin Sharma <vipinsh@google.com>

Reviewed-by: Pratyush Yadav (Google) <pratyush@kernel.org>

[...]

-- 
Regards,
Pratyush Yadav