#include <sys/mman.h>
#include <sys/wait.h>
+#include "local_config.h"
+#ifdef LOCAL_CONFIG_HAVE_LIBURING
+#include <liburing.h>
+#endif /* LOCAL_CONFIG_HAVE_LIBURING */
+
#include "../kselftest.h"
#include "vm_util.h"
do_test_vmsplice_in_parent(mem, size, false);
}
+#ifdef LOCAL_CONFIG_HAVE_LIBURING
+static void do_test_iouring(char *mem, size_t size, bool use_fork)
+{
+ struct comm_pipes comm_pipes;
+ struct io_uring_cqe *cqe;
+ struct io_uring_sqe *sqe;
+ struct io_uring ring;
+ ssize_t cur, total;
+ struct iovec iov;
+ char *buf, *tmp;
+ int ret, fd;
+ FILE *file;
+
+ ret = setup_comm_pipes(&comm_pipes);
+ if (ret) {
+ ksft_test_result_fail("pipe() failed\n");
+ return;
+ }
+
+ file = tmpfile();
+ if (!file) {
+ ksft_test_result_fail("tmpfile() failed\n");
+ goto close_comm_pipes;
+ }
+ fd = fileno(file);
+ assert(fd);
+
+ tmp = malloc(size);
+ if (!tmp) {
+ ksft_test_result_fail("malloc() failed\n");
+ goto close_file;
+ }
+
+ /* Skip on errors, as we might just lack kernel support. */
+ ret = io_uring_queue_init(1, &ring, 0);
+ if (ret < 0) {
+ ksft_test_result_skip("io_uring_queue_init() failed\n");
+ goto free_tmp;
+ }
+
+ /*
+ * Register the range as a fixed buffer. This will FOLL_WRITE | FOLL_PIN
+ * | FOLL_LONGTERM the range.
+ *
+ * Skip on errors, as we might just lack kernel support or might not
+ * have sufficient MEMLOCK permissions.
+ */
+ iov.iov_base = mem;
+ iov.iov_len = size;
+ ret = io_uring_register_buffers(&ring, &iov, 1);
+ if (ret) {
+ ksft_test_result_skip("io_uring_register_buffers() failed\n");
+ goto queue_exit;
+ }
+
+ if (use_fork) {
+ /*
+ * fork() and keep the child alive until we're done. Note that
+ * we expect the pinned page to not get shared with the child.
+ */
+ ret = fork();
+ if (ret < 0) {
+ ksft_test_result_fail("fork() failed\n");
+ goto unregister_buffers;
+ } else if (!ret) {
+ write(comm_pipes.child_ready[1], "0", 1);
+ while (read(comm_pipes.parent_ready[0], &buf, 1) != 1)
+ ;
+ exit(0);
+ }
+
+ while (read(comm_pipes.child_ready[0], &buf, 1) != 1)
+ ;
+ } else {
+ /*
+ * Map the page R/O into the page table. Enable softdirty
+ * tracking to stop the page from getting mapped R/W immediately
+ * again by mprotect() optimizations. Note that we don't have an
+ * easy way to test if that worked (the pagemap does not export
+ * if the page is mapped R/O vs. R/W).
+ */
+ ret = mprotect(mem, size, PROT_READ);
+ clear_softdirty();
+ ret |= mprotect(mem, size, PROT_READ | PROT_WRITE);
+ if (ret) {
+ ksft_test_result_fail("mprotect() failed\n");
+ goto unregister_buffers;
+ }
+ }
+
+ /*
+ * Modify the page and write page content as observed by the fixed
+ * buffer pin to the file so we can verify it.
+ */
+ memset(mem, 0xff, size);
+ sqe = io_uring_get_sqe(&ring);
+ if (!sqe) {
+ ksft_test_result_fail("io_uring_get_sqe() failed\n");
+ goto quit_child;
+ }
+ io_uring_prep_write_fixed(sqe, fd, mem, size, 0, 0);
+
+ ret = io_uring_submit(&ring);
+ if (ret < 0) {
+ ksft_test_result_fail("io_uring_submit() failed\n");
+ goto quit_child;
+ }
+
+ ret = io_uring_wait_cqe(&ring, &cqe);
+ if (ret < 0) {
+ ksft_test_result_fail("io_uring_wait_cqe() failed\n");
+ goto quit_child;
+ }
+
+ if (cqe->res != size) {
+ ksft_test_result_fail("write_fixed failed\n");
+ goto quit_child;
+ }
+ io_uring_cqe_seen(&ring, cqe);
+
+ /* Read back the file content to the temporary buffer. */
+ total = 0;
+ while (total < size) {
+ cur = pread(fd, tmp + total, size - total, total);
+ if (cur < 0) {
+ ksft_test_result_fail("pread() failed\n");
+ goto quit_child;
+ }
+ total += cur;
+ }
+
+ /* Finally, check if we read what we expected. */
+ ksft_test_result(!memcmp(mem, tmp, size),
+ "Longterm R/W pin is reliable\n");
+
+quit_child:
+ if (use_fork) {
+ write(comm_pipes.parent_ready[1], "0", 1);
+ wait(&ret);
+ }
+unregister_buffers:
+ io_uring_unregister_buffers(&ring);
+queue_exit:
+ io_uring_queue_exit(&ring);
+free_tmp:
+ free(tmp);
+close_file:
+ fclose(file);
+close_comm_pipes:
+ close_comm_pipes(&comm_pipes);
+}
+
+static void test_iouring_ro(char *mem, size_t size)
+{
+ do_test_iouring(mem, size, false);
+}
+
+static void test_iouring_fork(char *mem, size_t size)
+{
+ do_test_iouring(mem, size, true);
+}
+
+#endif /* LOCAL_CONFIG_HAVE_LIBURING */
+
typedef void (*test_fn)(char *mem, size_t size);
static void do_run_with_base_page(test_fn fn, bool swapout)
"vmsplice() + unmap in parent after fork()",
test_vmsplice_after_fork,
},
+#ifdef LOCAL_CONFIG_HAVE_LIBURING
+ /*
+ * Take a R/W longterm pin and then map the page R/O into the page
+ * table to trigger a write fault on next access. When modifying the
+ * page, the page content must be visible via the pin.
+ */
+ {
+ "R/O-mapping a page registered as iouring fixed buffer",
+ test_iouring_ro,
+ },
+ /*
+ * Take a R/W longterm pin and then fork() a child. When modifying the
+ * page, the page content must be visible via the pin. We expect the
+ * pinned page to not get shared with the child.
+ */
+ {
+ "fork() with an iouring fixed buffer",
+ test_iouring_fork,
+ },
+
+#endif /* LOCAL_CONFIG_HAVE_LIBURING */
};
static void run_test_case(struct test_case const *test_case)
projects / nvme.git / commitdiff