* [PATCH liburing 1/3] Revert "test/io_uring_register: kill old memfd test"
2025-07-15 5:06 [PATCH liburing 0/3] Bring back `CONFIG_HAVE_MEMFD_CREATE` to fix Android build error Alviro Iskandar Setiawan
@ 2025-07-15 5:06 ` Alviro Iskandar Setiawan
2025-07-15 14:10 ` Jens Axboe
2025-07-15 5:06 ` [PATCH liburing 2/3] test: Move `memfd_create()` to helpers.c, make it accessible for all tests Alviro Iskandar Setiawan
2025-07-15 5:06 ` [PATCH liburing 3/3] examples: Add `memfd_create()` helper Alviro Iskandar Setiawan
2 siblings, 1 reply; 6+ messages in thread
From: Alviro Iskandar Setiawan @ 2025-07-15 5:06 UTC (permalink / raw)
To: Jens Axboe
Cc: Alviro Iskandar Setiawan, Linux Kernel Mailing List,
io-uring Mailing List, GNU/Weeb Mailing List, Ammar Faizi
This reverts commit 732bf609b670631731765a585a68d14ed3fdc9b7.
Bring back `CONFIG_HAVE_MEMFD_CREATE` and the associated memfd test
to resolve Android build failures caused by:
93d3a7a70b4a ("examples/zcrx: udmabuf backed areas")
It added a call to `memfd_create()`, which is unavailable on some
Android toolchains, leading to the following build error:
```
zcrx.c:111:10: error: call to undeclared function 'memfd_create'; ISO C99 and \
later do not support implicit function declarations \
[-Wimplicit-function-declaration]
111 | memfd = memfd_create("udmabuf-test", MFD_ALLOW_SEALING);
| ^
```
This reversion is a preparation step for a proper fix by ensuring
`memfd_create()` usage is guarded and portable. Issue #620 was
initially unclear, but we now suspect it stemmed from improper
compiler/linker flag combinations.
Co-authored-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Signed-off-by: Alviro Iskandar Setiawan <alviro.iskandar@gnuweeb.org>
---
configure | 19 +++++++
test/io_uring_register.c | 119 +++++++++++++++++++++++++++++++++++++++
2 files changed, 138 insertions(+)
diff --git a/configure b/configure
index 552f8ae..3c95214 100755
--- a/configure
+++ b/configure
@@ -379,6 +379,22 @@ if compile_prog "" "" "has_ucontext"; then
fi
print_config "has_ucontext" "$has_ucontext"
+##########################################
+# check for memfd_create(2)
+has_memfd_create="no"
+cat > $TMPC << EOF
+#include <sys/mman.h>
+int main(int argc, char **argv)
+{
+ int memfd = memfd_create("test", 0);
+ return 0;
+}
+EOF
+if compile_prog "-Werror=implicit-function-declaration" "" "has_memfd_create"; then
+ has_memfd_create="yes"
+fi
+print_config "has_memfd_create" "$has_memfd_create"
+
##########################################
# Check NVME_URING_CMD support
nvme_uring_cmd="no"
@@ -539,6 +555,9 @@ fi
if test "$array_bounds" = "yes"; then
output_sym "CONFIG_HAVE_ARRAY_BOUNDS"
fi
+if test "$has_memfd_create" = "yes"; then
+ output_sym "CONFIG_HAVE_MEMFD_CREATE"
+fi
if test "$nvme_uring_cmd" = "yes"; then
output_sym "CONFIG_HAVE_NVME_URING"
fi
diff --git a/test/io_uring_register.c b/test/io_uring_register.c
index b53a67d..f08f0ca 100644
--- a/test/io_uring_register.c
+++ b/test/io_uring_register.c
@@ -32,6 +32,17 @@ static int pagesize;
static rlim_t mlock_limit;
static int devnull;
+#if !defined(CONFIG_HAVE_MEMFD_CREATE)
+#include <sys/syscall.h>
+#include <linux/memfd.h>
+
+static int memfd_create(const char *name, unsigned int flags)
+{
+ return (int)syscall(SYS_memfd_create, name, flags);
+}
+#endif
+
+
static int expect_fail(int fd, unsigned int opcode, void *arg,
unsigned int nr_args, int error, int error2)
{
@@ -466,6 +477,113 @@ static int __test_poll_ringfd(int ring_flags)
return status;
}
+static int test_shmem(void)
+{
+ const char pattern = 0xEA;
+ const int len = 4096;
+ struct io_uring_sqe *sqe;
+ struct io_uring_cqe *cqe;
+ struct io_uring ring;
+ struct iovec iov;
+ int memfd, ret, i;
+ char *mem;
+ int pipefd[2] = {-1, -1};
+
+ ret = io_uring_queue_init(8, &ring, 0);
+ if (ret)
+ return 1;
+
+ if (pipe(pipefd)) {
+ perror("pipe");
+ return 1;
+ }
+ memfd = memfd_create("uring-shmem-test", 0);
+ if (memfd < 0) {
+ fprintf(stderr, "memfd_create() failed %i\n", -errno);
+ return 1;
+ }
+ if (ftruncate(memfd, len)) {
+ fprintf(stderr, "can't truncate memfd\n");
+ return 1;
+ }
+ mem = mmap(NULL, len, PROT_READ | PROT_WRITE, MAP_SHARED, memfd, 0);
+ if (!mem) {
+ fprintf(stderr, "mmap failed\n");
+ return 1;
+ }
+ for (i = 0; i < len; i++)
+ mem[i] = pattern;
+
+ iov.iov_base = mem;
+ iov.iov_len = len;
+ ret = io_uring_register_buffers(&ring, &iov, 1);
+ if (ret) {
+ if (ret == -EOPNOTSUPP) {
+ fprintf(stdout, "memfd registration isn't supported, "
+ "skip\n");
+ goto out;
+ }
+
+ fprintf(stderr, "buffer reg failed: %d\n", ret);
+ return 1;
+ }
+
+ /* check that we can read and write from/to shmem reg buffer */
+ sqe = io_uring_get_sqe(&ring);
+ io_uring_prep_write_fixed(sqe, pipefd[1], mem, 512, 0, 0);
+ sqe->user_data = 1;
+
+ ret = io_uring_submit(&ring);
+ if (ret != 1) {
+ fprintf(stderr, "submit write failed\n");
+ return 1;
+ }
+ ret = io_uring_wait_cqe(&ring, &cqe);
+ if (ret < 0 || cqe->user_data != 1 || cqe->res != 512) {
+ fprintf(stderr, "reading from shmem failed\n");
+ return 1;
+ }
+ io_uring_cqe_seen(&ring, cqe);
+
+ /* clean it, should be populated with the pattern back from the pipe */
+ memset(mem, 0, 512);
+ sqe = io_uring_get_sqe(&ring);
+ io_uring_prep_read_fixed(sqe, pipefd[0], mem, 512, 0, 0);
+ sqe->user_data = 2;
+
+ ret = io_uring_submit(&ring);
+ if (ret != 1) {
+ fprintf(stderr, "submit write failed\n");
+ return 1;
+ }
+ ret = io_uring_wait_cqe(&ring, &cqe);
+ if (ret < 0 || cqe->user_data != 2 || cqe->res != 512) {
+ fprintf(stderr, "reading from shmem failed\n");
+ return 1;
+ }
+ io_uring_cqe_seen(&ring, cqe);
+
+ for (i = 0; i < 512; i++) {
+ if (mem[i] != pattern) {
+ fprintf(stderr, "data integrity fail\n");
+ return 1;
+ }
+ }
+
+ ret = io_uring_unregister_buffers(&ring);
+ if (ret) {
+ fprintf(stderr, "buffer unreg failed: %d\n", ret);
+ return 1;
+ }
+out:
+ io_uring_queue_exit(&ring);
+ close(pipefd[0]);
+ close(pipefd[1]);
+ munmap(mem, len);
+ close(memfd);
+ return 0;
+}
+
static int test_poll_ringfd(void)
{
int ret;
@@ -526,6 +644,7 @@ int main(int argc, char **argv)
/* uring poll on the uring fd */
status |= test_poll_ringfd();
+ status |= test_shmem();
if (status)
fprintf(stderr, "FAIL\n");
--
Alviro Iskandar Setiawan
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH liburing 2/3] test: Move `memfd_create()` to helpers.c, make it accessible for all tests
2025-07-15 5:06 [PATCH liburing 0/3] Bring back `CONFIG_HAVE_MEMFD_CREATE` to fix Android build error Alviro Iskandar Setiawan
2025-07-15 5:06 ` [PATCH liburing 1/3] Revert "test/io_uring_register: kill old memfd test" Alviro Iskandar Setiawan
@ 2025-07-15 5:06 ` Alviro Iskandar Setiawan
2025-07-15 5:06 ` [PATCH liburing 3/3] examples: Add `memfd_create()` helper Alviro Iskandar Setiawan
2 siblings, 0 replies; 6+ messages in thread
From: Alviro Iskandar Setiawan @ 2025-07-15 5:06 UTC (permalink / raw)
To: Jens Axboe
Cc: Alviro Iskandar Setiawan, Linux Kernel Mailing List,
io-uring Mailing List, GNU/Weeb Mailing List, Ammar Faizi
Previously, the static definition of `memfd_create()` was limited to
io_uring_register.c. Now, promote it to a shared location accessible
to all test cases, ensuring that future tests using `memfd_create()`
do not trigger build failures on Android targets where the syscall
is undefined in the standard headers. It improves portability and
prevents regressions across test builds.
Co-authored-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Signed-off-by: Alviro Iskandar Setiawan <alviro.iskandar@gnuweeb.org>
---
test/helpers.c | 8 ++++++++
test/helpers.h | 5 +++++
test/io_uring_register.c | 11 -----------
3 files changed, 13 insertions(+), 11 deletions(-)
diff --git a/test/helpers.c b/test/helpers.c
index 0589548..f1d4477 100644
--- a/test/helpers.c
+++ b/test/helpers.c
@@ -18,6 +18,14 @@
#include "helpers.h"
#include "liburing.h"
+#ifndef CONFIG_HAVE_MEMFD_CREATE
+#include <sys/syscall.h>
+int memfd_create(const char *name, unsigned int flags)
+{
+ return (int)syscall(SYS_memfd_create, name, flags);
+}
+#endif
+
/*
* Helper for allocating memory in tests.
*/
diff --git a/test/helpers.h b/test/helpers.h
index 3f0c11a..8ab0920 100644
--- a/test/helpers.h
+++ b/test/helpers.h
@@ -122,6 +122,11 @@ unsigned long long mtime_since_now(struct timeval *tv);
unsigned long long utime_since(const struct timeval *s, const struct timeval *e);
unsigned long long utime_since_now(struct timeval *tv);
+#ifndef CONFIG_HAVE_MEMFD_CREATE
+#include <linux/memfd.h>
+#endif
+int memfd_create(const char *name, unsigned int flags);
+
#ifdef __cplusplus
}
#endif
diff --git a/test/io_uring_register.c b/test/io_uring_register.c
index f08f0ca..c36c4d8 100644
--- a/test/io_uring_register.c
+++ b/test/io_uring_register.c
@@ -32,17 +32,6 @@ static int pagesize;
static rlim_t mlock_limit;
static int devnull;
-#if !defined(CONFIG_HAVE_MEMFD_CREATE)
-#include <sys/syscall.h>
-#include <linux/memfd.h>
-
-static int memfd_create(const char *name, unsigned int flags)
-{
- return (int)syscall(SYS_memfd_create, name, flags);
-}
-#endif
-
-
static int expect_fail(int fd, unsigned int opcode, void *arg,
unsigned int nr_args, int error, int error2)
{
--
Alviro Iskandar Setiawan
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH liburing 3/3] examples: Add `memfd_create()` helper
2025-07-15 5:06 [PATCH liburing 0/3] Bring back `CONFIG_HAVE_MEMFD_CREATE` to fix Android build error Alviro Iskandar Setiawan
2025-07-15 5:06 ` [PATCH liburing 1/3] Revert "test/io_uring_register: kill old memfd test" Alviro Iskandar Setiawan
2025-07-15 5:06 ` [PATCH liburing 2/3] test: Move `memfd_create()` to helpers.c, make it accessible for all tests Alviro Iskandar Setiawan
@ 2025-07-15 5:06 ` Alviro Iskandar Setiawan
2 siblings, 0 replies; 6+ messages in thread
From: Alviro Iskandar Setiawan @ 2025-07-15 5:06 UTC (permalink / raw)
To: Jens Axboe
Cc: Alviro Iskandar Setiawan, Linux Kernel Mailing List,
io-uring Mailing List, GNU/Weeb Mailing List, Ammar Faizi
Add `memfd_create()` helper to handle missing defintion on an environment
where `CONFIG_HAVE_MEMFD_CREATE` is not defined.
Co-authored-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Signed-off-by: Alviro Iskandar Setiawan <alviro.iskandar@gnuweeb.org>
---
examples/helpers.c | 8 ++++++++
examples/helpers.h | 5 +++++
2 files changed, 13 insertions(+)
diff --git a/examples/helpers.c b/examples/helpers.c
index 483ddee..8c112f1 100644
--- a/examples/helpers.c
+++ b/examples/helpers.c
@@ -13,6 +13,14 @@
#include "helpers.h"
+#ifndef CONFIG_HAVE_MEMFD_CREATE
+#include <sys/syscall.h>
+int memfd_create(const char *name, unsigned int flags)
+{
+ return (int)syscall(SYS_memfd_create, name, flags);
+}
+#endif
+
int setup_listening_socket(int port, int ipv6)
{
struct sockaddr_in srv_addr = { };
diff --git a/examples/helpers.h b/examples/helpers.h
index 44543e1..0b6f15f 100644
--- a/examples/helpers.h
+++ b/examples/helpers.h
@@ -17,4 +17,9 @@ void *t_aligned_alloc(size_t alignment, size_t size);
void t_error(int status, int errnum, const char *format, ...);
+#ifndef CONFIG_HAVE_MEMFD_CREATE
+#include <linux/memfd.h>
+#endif
+int memfd_create(const char *name, unsigned int flags);
+
#endif
--
Alviro Iskandar Setiawan
^ permalink raw reply related [flat|nested] 6+ messages in thread