[PATCH 2/2] selftests/nolibc: Add basic test for sendfile()

[Daniel Palmer <daniel@thingy.jp>]

Basic smoke test for sendfile().

Signed-off-by: Daniel Palmer <daniel@thingy.jp>
---
 tools/testing/selftests/nolibc/nolibc-test.c | 70 ++++++++++++++++++++
 1 file changed, 70 insertions(+)

diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index ed860b0a15a1..48e1183a00bb 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -1563,6 +1563,75 @@ int test_large_file(void)
 	return ret;
 }
 
+int test_sendfile(void)
+{
+	char data_in[] = "This is some data";
+	const size_t data_sz = sizeof(data_in);
+	char data_out[data_sz];
+	int in_fd, out_fd;
+	int ret = 0;
+
+	/* Create two tmp files */
+	in_fd = open("/tmp", O_TMPFILE | O_RDWR, 0644);
+	if (in_fd == -1)
+		return __LINE__;
+
+	out_fd = open("/tmp", O_TMPFILE | O_RDWR, 0644);
+	if (out_fd == -1) {
+		ret = __LINE__;
+		goto close_in;
+	}
+
+	/* Populate the "in" file */
+	ret = write(in_fd, data_in, data_sz);
+	if (ret != data_sz) {
+		ret = __LINE__;
+		goto close_out;
+	}
+
+	/* Rewind the "in" file */
+	if (lseek(in_fd, 0, SEEK_SET)) {
+		ret = __LINE__;
+		goto close_out;
+	}
+
+	/* Use sendfile() to copy "in" to "out" */
+	ret = sendfile(out_fd, in_fd, NULL, data_sz);
+	if (ret != data_sz) {
+		ret = __LINE__;
+		goto close_out;
+	}
+
+	/* Rewind the "out" file */
+	if (lseek(out_fd, 0, SEEK_SET)) {
+		ret = __LINE__;
+		goto close_out;
+	}
+
+	/* Read back the transferred data */
+	ret = read(out_fd, data_out, data_sz);
+	if (ret != data_sz) {
+		ret = __LINE__;
+		goto close_out;
+	}
+
+	/* Check we have the same data in both files */
+	if (memcmp(data_out, data_in, data_sz)) {
+		ret = __LINE__;
+		goto close_out;
+	}
+
+	/* Test passed */
+	ret = 0;
+
+close_out:
+	close(out_fd);
+close_in:
+	close(in_fd);
+
+	return ret;
+}
+
 /* Run syscall tests between IDs <min> and <max>.
  * Return 0 on success, non-zero on failure.
  */
@@ -1684,6 +1753,7 @@ int run_syscall(int min, int max)
 		CASE_TEST(select_null);       EXPECT_SYSZR(1, ({ struct timeval tv = { 0 }; select(0, NULL, NULL, NULL, &tv); })); break;
 		CASE_TEST(select_stdout);     EXPECT_SYSNE(1, ({ fd_set fds; FD_ZERO(&fds); FD_SET(1, &fds); select(2, NULL, &fds, NULL, NULL); }), -1); break;
 		CASE_TEST(select_fault);      EXPECT_SYSER(1, select(1, (void *)1, NULL, NULL, 0), -1, EFAULT); break;
+		CASE_TEST(sendfile);          EXPECT_SYSZR(1, test_sendfile()); break;
 		CASE_TEST(stat_blah);         EXPECT_SYSER(1, stat("/proc/self/blah", &stat_buf), -1, ENOENT); break;
 		CASE_TEST(stat_fault);        EXPECT_SYSER(1, stat(NULL, &stat_buf), -1, EFAULT); break;
 		CASE_TEST(stat_rdev);         EXPECT_SYSZR(1, ({ int ret = stat("/dev/null", &stat_buf); ret ?: stat_buf.st_rdev != makedev(1, 3); })); break;
-- 
2.53.0