If many dmabufs are present, reads of the dmabuf iterator can be truncated at PAGE_SIZE or user buffer size boundaries before the fix in "selftests/bpf: Add test for open coded dmabuf_iter". Add a test to confirm truncation does not occur.
Signed-off-by: T.J. Mercier tjmercier@google.com --- .../selftests/bpf/prog_tests/dmabuf_iter.c | 47 +++++++++++++++++-- 1 file changed, 42 insertions(+), 5 deletions(-)
diff --git a/tools/testing/selftests/bpf/prog_tests/dmabuf_iter.c b/tools/testing/selftests/bpf/prog_tests/dmabuf_iter.c index 6c2b0c3dbcd8..e442be9dde7e 100644 --- a/tools/testing/selftests/bpf/prog_tests/dmabuf_iter.c +++ b/tools/testing/selftests/bpf/prog_tests/dmabuf_iter.c @@ -73,12 +73,10 @@ static int create_udmabuf(void) return -1; }
-static int create_sys_heap_dmabuf(void) +static int create_sys_heap_dmabuf(size_t bytes) { - sysheap_test_buffer_size = 20 * getpagesize(); - struct dma_heap_allocation_data data = { - .len = sysheap_test_buffer_size, + .len = bytes, .fd = 0, .fd_flags = O_RDWR | O_CLOEXEC, .heap_flags = 0, @@ -110,7 +108,9 @@ static int create_sys_heap_dmabuf(void) static int create_test_buffers(void) { udmabuf = create_udmabuf(); - sysheap_dmabuf = create_sys_heap_dmabuf(); + + sysheap_test_buffer_size = 20 * getpagesize(); + sysheap_dmabuf = create_sys_heap_dmabuf(sysheap_test_buffer_size);
if (udmabuf < 0 || sysheap_dmabuf < 0) return -1; @@ -219,6 +219,26 @@ static void subtest_dmabuf_iter_check_default_iter(struct dmabuf_iter *skel) close(iter_fd); }
+static void subtest_dmabuf_iter_check_lots_of_buffers(struct dmabuf_iter *skel) +{ + int iter_fd; + char buf[1024]; + size_t total_bytes_read = 0; + ssize_t bytes_read; + + iter_fd = bpf_iter_create(bpf_link__fd(skel->links.dmabuf_collector)); + if (!ASSERT_OK_FD(iter_fd, "iter_create")) + return; + + while ((bytes_read = read(iter_fd, buf, sizeof(buf))) > 0) + total_bytes_read += bytes_read; + + ASSERT_GT(total_bytes_read, getpagesize(), "total_bytes_read"); + + 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); @@ -275,6 +295,23 @@ void test_dmabuf_iter(void) 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("lots_of_buffers")) { + size_t NUM_BUFS = 100; + int buffers[NUM_BUFS]; + int i; + + for (i = 0; i < NUM_BUFS; ++i) { + buffers[i] = create_sys_heap_dmabuf(getpagesize()); + if (!ASSERT_OK_FD(buffers[i], "dmabuf_fd")) + goto cleanup_bufs; + } + + subtest_dmabuf_iter_check_lots_of_buffers(skel); + +cleanup_bufs: + for (--i; i >= 0; --i) + close(buffers[i]); + } if (test__start_subtest("open_coded")) subtest_dmabuf_iter_check_open_coded(skel, map_fd);