diff mbox series

[bpf-next,v1,7/8] selftests/bpf: Test partial reads for io_uring, epoll iterators

Message ID 20211116054237.100814-8-memxor@gmail.com (mailing list archive)
State Superseded
Delegated to: BPF
Headers show
Series Introduce BPF iterators for io_uring and epoll | expand

Checks

Context Check Description
bpf/vmtest-bpf-next-PR fail PR summary
netdev/tree_selection success Clearly marked for bpf-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers warning 9 maintainers not CCed: kafai@fb.com yhs@fb.com songliubraving@fb.com john.fastabend@gmail.com revest@chromium.org shuah@kernel.org netdev@vger.kernel.org linux-kselftest@vger.kernel.org kpsingh@kernel.org
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 92 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
bpf/vmtest-bpf-next fail VM_Test

Commit Message

Kumar Kartikeya Dwivedi Nov. 16, 2021, 5:42 a.m. UTC 
Ensure that the output is consistent in face of partial reads that
return to userspace and then resume again later. To this end, we do
reads in 1-byte chunks, which is a bit stupid in real life, but works
well to simulate interrupted iteration. This also tests case where
seq_file buffer is consumed (after seq_printf) on interrupted read
before iterator invoked BPF prog again.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
---
 .../selftests/bpf/prog_tests/bpf_iter.c       | 33 ++++++++++++-------
 1 file changed, 22 insertions(+), 11 deletions(-)
diff mbox series

Patch

diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c
index 45e186385f9a..c27f3e10211c 100644
--- a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c
+++ b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c
@@ -72,13 +72,13 @@  static void do_dummy_read(struct bpf_program *prog)
 	bpf_link__destroy(link);
 }
 
-static int read_fd_into_buffer(int fd, char *buf, int size)
+static int __read_fd_into_buffer(int fd, char *buf, int size, size_t chunks)
 {
 	int bufleft = size;
 	int len;
 
 	do {
-		len = read(fd, buf, bufleft);
+		len = read(fd, buf, chunks ?: bufleft);
 		if (len > 0) {
 			buf += len;
 			bufleft -= len;
@@ -88,6 +88,11 @@  static int read_fd_into_buffer(int fd, char *buf, int size)
 	return len < 0 ? len : size - bufleft;
 }
 
+static int read_fd_into_buffer(int fd, char *buf, int size)
+{
+	return __read_fd_into_buffer(fd, buf, size, 0);
+}
+
 static void test_ipv6_route(void)
 {
 	struct bpf_iter_ipv6_route *skel;
@@ -1281,7 +1286,7 @@  static unsigned long long page_addr_to_pfn(unsigned long addr)
 	return pfn & 0x7fffffffffffff;
 }
 
-void test_io_uring_buf(void)
+void test_io_uring_buf(bool partial)
 {
 	DECLARE_LIBBPF_OPTS(bpf_iter_attach_opts, opts);
 	char rbuf[4096], buf[4096] = "B\n";
@@ -1352,7 +1357,7 @@  void test_io_uring_buf(void)
 	if (!ASSERT_GE(iter_fd, 0, "bpf_iter_create"))
 		goto end_close_fd;
 
-	ret = read_fd_into_buffer(iter_fd, rbuf, sizeof(rbuf));
+	ret = __read_fd_into_buffer(iter_fd, rbuf, sizeof(rbuf), partial);
 	if (!ASSERT_GT(ret, 0, "read_fd_into_buffer"))
 		goto end_close_iter;
 
@@ -1374,7 +1379,7 @@  void test_io_uring_buf(void)
 	bpf_iter_io_uring__destroy(skel);
 }
 
-void test_io_uring_file(void)
+void test_io_uring_file(bool partial)
 {
 	int reg_files[] = { [0 ... 7] = -1 };
 	DECLARE_LIBBPF_OPTS(bpf_iter_attach_opts, opts);
@@ -1439,7 +1444,7 @@  void test_io_uring_file(void)
 	if (!ASSERT_OK(ret, "io_uring_register_files"))
 		goto end_iter_fd;
 
-	ret = read_fd_into_buffer(iter_fd, rbuf, sizeof(rbuf));
+	ret = __read_fd_into_buffer(iter_fd, rbuf, sizeof(rbuf), partial);
 	if (!ASSERT_GT(ret, 0, "read_fd_into_buffer(iterator_fd, buf)"))
 		goto end_iter_fd;
 
@@ -1463,7 +1468,7 @@  void test_io_uring_file(void)
 	bpf_iter_io_uring__destroy(skel);
 }
 
-void test_epoll(void)
+void test_epoll(bool partial)
 {
 	const char *fmt = "B\npipe:%d\nsocket:%d\npipe:%d\nsocket:%d\nE\n";
 	DECLARE_LIBBPF_OPTS(bpf_iter_attach_opts, opts);
@@ -1529,7 +1534,7 @@  void test_epoll(void)
 	if (!ASSERT_GE(ret, 0, "snprintf") || !ASSERT_LT(ret, sizeof(buf), "snprintf"))
 		goto end_iter_fd;
 
-	ret = read_fd_into_buffer(iter_fd, rbuf, sizeof(rbuf));
+	ret = __read_fd_into_buffer(iter_fd, rbuf, sizeof(rbuf), partial);
 	if (!ASSERT_GT(ret, 0, "read_fd_into_buffer"))
 		goto end_iter_fd;
 
@@ -1641,9 +1646,15 @@  void test_bpf_iter(void)
 	if (test__start_subtest("buf-neg-offset"))
 		test_buf_neg_offset();
 	if (test__start_subtest("io_uring_buf"))
-		test_io_uring_buf();
+		test_io_uring_buf(false);
 	if (test__start_subtest("io_uring_file"))
-		test_io_uring_file();
+		test_io_uring_file(false);
 	if (test__start_subtest("epoll"))
-		test_epoll();
+		test_epoll(false);
+	if (test__start_subtest("io_uring_buf-partial"))
+		test_io_uring_buf(true);
+	if (test__start_subtest("io_uring_file-partial"))
+		test_io_uring_file(true);
+	if (test__start_subtest("epoll-partial"))
+		test_epoll(true);
 }