1 files changed, 285 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/dmabuf_iter.c b/tools/testing/selftests/bpf/prog_tests/dmabuf_iter.c
new file mode 100644
index 000000000000..6c2b0c3dbcd8
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/dmabuf_iter.c
@@ -0,0 +1,285 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2025 Google */
+
+#include <test_progs.h>
+#include <bpf/libbpf.h>
+#include <bpf/btf.h>
+#include "dmabuf_iter.skel.h"
+
+#include <fcntl.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <unistd.h>
+
+#include <linux/dma-buf.h>
+#include <linux/dma-heap.h>
+#include <linux/udmabuf.h>
+
+static int udmabuf = -1;
+static const char udmabuf_test_buffer_name[DMA_BUF_NAME_LEN] = "udmabuf_test_buffer_for_iter";
+static size_t udmabuf_test_buffer_size;
+static int sysheap_dmabuf = -1;
+static const char sysheap_test_buffer_name[DMA_BUF_NAME_LEN] = "sysheap_test_buffer_for_iter";
+static size_t sysheap_test_buffer_size;
+
+static int create_udmabuf(void)
+{
+	struct udmabuf_create create;
+	int dev_udmabuf, memfd, local_udmabuf;
+
+	udmabuf_test_buffer_size = 10 * getpagesize();
+
+	if (!ASSERT_LE(sizeof(udmabuf_test_buffer_name), DMA_BUF_NAME_LEN, "NAMETOOLONG"))
+		return -1;
+
+	memfd = memfd_create("memfd_test", MFD_ALLOW_SEALING);
+	if (!ASSERT_OK_FD(memfd, "memfd_create"))
+		return -1;
+
+	if (!ASSERT_OK(ftruncate(memfd, udmabuf_test_buffer_size), "ftruncate"))
+		goto close_memfd;
+
+	if (!ASSERT_OK(fcntl(memfd, F_ADD_SEALS, F_SEAL_SHRINK), "seal"))
+		goto close_memfd;
+
+	dev_udmabuf = open("/dev/udmabuf", O_RDONLY);
+	if (!ASSERT_OK_FD(dev_udmabuf, "open udmabuf"))
+		goto close_memfd;
+
+	memset(&create, 0, sizeof(create));
+	create.memfd = memfd;
+	create.flags = UDMABUF_FLAGS_CLOEXEC;
+	create.offset = 0;
+	create.size = udmabuf_test_buffer_size;
+
+	local_udmabuf = ioctl(dev_udmabuf, UDMABUF_CREATE, &create);
+	close(dev_udmabuf);
+	if (!ASSERT_OK_FD(local_udmabuf, "udmabuf_create"))
+		goto close_memfd;
+
+	if (!ASSERT_OK(ioctl(local_udmabuf, DMA_BUF_SET_NAME_B, udmabuf_test_buffer_name), "name"))
+		goto close_udmabuf;
+
+	return local_udmabuf;
+
+close_udmabuf:
+	close(local_udmabuf);
+close_memfd:
+	close(memfd);
+	return -1;
+}
+
+static int create_sys_heap_dmabuf(void)
+{
+	sysheap_test_buffer_size = 20 * getpagesize();
+
+	struct dma_heap_allocation_data data = {
+		.len = sysheap_test_buffer_size,
+		.fd = 0,
+		.fd_flags = O_RDWR | O_CLOEXEC,
+		.heap_flags = 0,
+	};
+	int heap_fd, ret;
+
+	if (!ASSERT_LE(sizeof(sysheap_test_buffer_name), DMA_BUF_NAME_LEN, "NAMETOOLONG"))
+		return -1;
+
+	heap_fd = open("/dev/dma_heap/system", O_RDONLY);
+	if (!ASSERT_OK_FD(heap_fd, "open dma heap"))
+		return -1;
+
+	ret = ioctl(heap_fd, DMA_HEAP_IOCTL_ALLOC, &data);
+	close(heap_fd);
+	if (!ASSERT_OK(ret, "syheap alloc"))
+		return -1;
+
+	if (!ASSERT_OK(ioctl(data.fd, DMA_BUF_SET_NAME_B, sysheap_test_buffer_name), "name"))
+		goto close_sysheap_dmabuf;
+
+	return data.fd;
+
+close_sysheap_dmabuf:
+	close(data.fd);
+	return -1;
+}
+
+static int create_test_buffers(void)
+{
+	udmabuf = create_udmabuf();
+	sysheap_dmabuf = create_sys_heap_dmabuf();
+
+	if (udmabuf < 0 || sysheap_dmabuf < 0)
+		return -1;
+
+	return 0;
+}
+
+static void destroy_test_buffers(void)
+{
+	close(udmabuf);
+	udmabuf = -1;
+
+	close(sysheap_dmabuf);
+	sysheap_dmabuf = -1;
+}
+
+enum Fields { INODE, SIZE, NAME, EXPORTER, FIELD_COUNT };
+struct DmabufInfo {
+	unsigned long inode;
+	unsigned long size;
+	char name[DMA_BUF_NAME_LEN];
+	char exporter[32];
+};
+
+static bool check_dmabuf_info(const struct DmabufInfo *bufinfo,
+			      unsigned long size,
+			      const char *name, const char *exporter)
+{
+	return size == bufinfo->size &&
+	       !strcmp(name, bufinfo->name) &&
+	       !strcmp(exporter, bufinfo->exporter);
+}
+
+static void subtest_dmabuf_iter_check_no_infinite_reads(struct dmabuf_iter *skel)
+{
+	int iter_fd;
+	char buf[256];
+
+	iter_fd = bpf_iter_create(bpf_link__fd(skel->links.dmabuf_collector));
+	if (!ASSERT_OK_FD(iter_fd, "iter_create"))
+		return;
+
+	while (read(iter_fd, buf, sizeof(buf)) > 0)
+		; /* Read out all contents */
+
+	/* Next reads should return 0 */
+	ASSERT_EQ(read(iter_fd, buf, sizeof(buf)), 0, "read");
+
+	close(iter_fd);
+}
+
+static void subtest_dmabuf_iter_check_default_iter(struct dmabuf_iter *skel)
+{
+	bool found_test_sysheap_dmabuf = false;
+	bool found_test_udmabuf = false;
+	struct DmabufInfo bufinfo;
+	size_t linesize = 0;
+	char *line = NULL;
+	FILE *iter_file;
+	int iter_fd, f = INODE;
+
+	iter_fd = bpf_iter_create(bpf_link__fd(skel->links.dmabuf_collector));
+	if (!ASSERT_OK_FD(iter_fd, "iter_create"))
+		return;
+
+	iter_file = fdopen(iter_fd, "r");
+	if (!ASSERT_OK_PTR(iter_file, "fdopen"))
+		goto close_iter_fd;
+
+	while (getline(&line, &linesize, iter_file) != -1) {
+		if (f % FIELD_COUNT == INODE) {
+			ASSERT_EQ(sscanf(line, "%ld", &bufinfo.inode), 1,
+				  "read inode");
+		} else if (f % FIELD_COUNT == SIZE) {
+			ASSERT_EQ(sscanf(line, "%ld", &bufinfo.size), 1,
+				  "read size");
+		} else if (f % FIELD_COUNT == NAME) {
+			ASSERT_EQ(sscanf(line, "%s", bufinfo.name), 1,
+				  "read name");
+		} else if (f % FIELD_COUNT == EXPORTER) {
+			ASSERT_EQ(sscanf(line, "%31s", bufinfo.exporter), 1,
+				  "read exporter");
+
+			if (check_dmabuf_info(&bufinfo,
+					      sysheap_test_buffer_size,
+					      sysheap_test_buffer_name,
+					      "system"))
+				found_test_sysheap_dmabuf = true;
+			else if (check_dmabuf_info(&bufinfo,
+						   udmabuf_test_buffer_size,
+						   udmabuf_test_buffer_name,
+						   "udmabuf"))
+				found_test_udmabuf = true;
+		}
+		++f;
+	}
+
+	ASSERT_EQ(f % FIELD_COUNT, INODE, "number of fields");
+
+	ASSERT_TRUE(found_test_sysheap_dmabuf, "found_test_sysheap_dmabuf");
+	ASSERT_TRUE(found_test_udmabuf, "found_test_udmabuf");
+
+	free(line);
+	fclose(iter_file);
+close_iter_fd:
+	close(iter_fd);
+}
+
+static void subtest_dmabuf_iter_check_open_coded(struct dmabuf_iter *skel, int map_fd)
+{
+	LIBBPF_OPTS(bpf_test_run_opts, topts);
+	char key[DMA_BUF_NAME_LEN];
+	int err, fd;
+	bool found;
+
+	/* No need to attach it, just run it directly */
+	fd = bpf_program__fd(skel->progs.iter_dmabuf_for_each);
+
+	err = bpf_prog_test_run_opts(fd, &topts);
+	if (!ASSERT_OK(err, "test_run_opts err"))
+		return;
+	if (!ASSERT_OK(topts.retval, "test_run_opts retval"))
+		return;
+
+	if (!ASSERT_OK(bpf_map_get_next_key(map_fd, NULL, key), "get next key"))
+		return;
+
+	do {
+		ASSERT_OK(bpf_map_lookup_elem(map_fd, key, &found), "lookup");
+		ASSERT_TRUE(found, "found test buffer");
+	} while (bpf_map_get_next_key(map_fd, key, key));
+}
+
+void test_dmabuf_iter(void)
+{
+	struct dmabuf_iter *skel = NULL;
+	int map_fd;
+	const bool f = false;
+
+	skel = dmabuf_iter__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "dmabuf_iter__open_and_load"))
+		return;
+
+	map_fd = bpf_map__fd(skel->maps.testbuf_hash);
+	if (!ASSERT_OK_FD(map_fd, "map_fd"))
+		goto destroy_skel;
+
+	if (!ASSERT_OK(bpf_map_update_elem(map_fd, udmabuf_test_buffer_name, &f, BPF_ANY),
+		       "insert udmabuf"))
+		goto destroy_skel;
+	if (!ASSERT_OK(bpf_map_update_elem(map_fd, sysheap_test_buffer_name, &f, BPF_ANY),
+		       "insert sysheap buffer"))
+		goto destroy_skel;
+
+	if (!ASSERT_OK(create_test_buffers(), "create_test_buffers"))
+		goto destroy;
+
+	if (!ASSERT_OK(dmabuf_iter__attach(skel), "skel_attach"))
+		goto destroy;
+
+	if (test__start_subtest("no_infinite_reads"))
+		subtest_dmabuf_iter_check_no_infinite_reads(skel);
+	if (test__start_subtest("default_iter"))
+		subtest_dmabuf_iter_check_default_iter(skel);
+	if (test__start_subtest("open_coded"))
+		subtest_dmabuf_iter_check_open_coded(skel, map_fd);
+
+destroy:
+	destroy_test_buffers();
+destroy_skel:
+	dmabuf_iter__destroy(skel);
+}