[LTP] [PATCH 1/2] syscalls: Add test for splicing from /dev/zero and /dev/full

Cyril Hrubis
2024-03-20T10:01:22Z

Both of these devices produce zeroes when read.

Signed-off-by: Cyril Hrubis <chrubis@suse.cz>
---
runtest/syscalls | 1 +
testcases/kernel/syscalls/splice/.gitignore | 1 +
testcases/kernel/syscalls/splice/splice08.c | 88 +++++++++++++++++++++
3 files changed, 90 insertions(+)
create mode 100644 testcases/kernel/syscalls/splice/splice08.c

diff --git a/runtest/syscalls b/runtest/syscalls
index 4ed2b5602..0889f58a1 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls
@@ -1517,6 +1517,7 @@ splice04 splice04
splice05 splice05
splice06 splice06
splice07 splice07
+splice08 splice08

tee01 tee01
tee02 tee02
diff --git a/testcases/kernel/syscalls/splice/.gitignore b/testcases/kernel/syscalls/splice/.gitignore
index 88a8dff78..9453cf93a 100644
--- a/testcases/kernel/syscalls/splice/.gitignore
+++ b/testcases/kernel/syscalls/splice/.gitignore
@@ -5,3 +5,4 @@
/splice05
/splice06
/splice07
+/splice08
diff --git a/testcases/kernel/syscalls/splice/splice08.c b/testcases/kernel/syscalls/splice/splice08.c
new file mode 100644
index 000000000..cdd51b66c
--- /dev/null
+++ b/testcases/kernel/syscalls/splice/splice08.c
@@ -0,0 +1,88 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2024 Cyril Hrubis <chrubis@suse.cz>
+ */
+
+/*\
+ * [Description]
+ *
+ * Test for splicing from /dev/zero and /dev/full.
+ *
+ * The support for splicing from /dev/zero and /dev/full was removed in:
+ * c6585011bc1d ("splice: Remove generic_file_splice_read()")
+ *
+ * And added back in:
+ * 1b057bd800c3 ("drivers/char/mem: implement splice() for /dev/zero, /dev/full")
+ */
+
+#define _GNU_SOURCE
+#include "tst_test.h"
+
+static int fd_zero;
+static int fd_full;
+
+static void test_splice(unsigned int bytes, int dev_fd)
+{
+ int pipefd[2];
+ char buf[bytes];
+ size_t i;
+ int fail = 0;
+
+ memset(buf, 0xff, sizeof(buf));
+
+ SAFE_PIPE(pipefd);
+
+ TST_EXP_POSITIVE(splice(dev_fd, NULL, pipefd[1], NULL, sizeof(buf), 0));
+
+ if (!TST_PASS)
+ goto ret;
+
+ SAFE_READ(1, pipefd[0], buf, sizeof(buf));
+
+ for (i = 0; i < sizeof(buf); i++) {
+ if (buf[i])
+ fail++;
+ }
+
+ if (fail)
+ tst_res(TFAIL, "Non-zero bytes spliced from /dev/zero");
+ else
+ tst_res(TPASS, "All bytes spliced from /dev/zero are zeroed");
+
+ret:
+ SAFE_CLOSE(pipefd[0]);
+ SAFE_CLOSE(pipefd[1]);
+}
+
+static void verify_splice(unsigned int n)
+{
+ unsigned int bytes = 1009 * n;
+
+ tst_res(TINFO, "Splicing %u bytes from /dev/zero", bytes);
+ test_splice(bytes, fd_zero);
+ tst_res(TINFO, "Splicing %u bytes from /dev/full", bytes);
+ test_splice(bytes, fd_full);
+}
+
+static void setup(void)
+{
+ fd_zero = SAFE_OPEN("/dev/zero", O_RDONLY);
+ fd_full = SAFE_OPEN("/dev/full", O_RDONLY);
+}
+
+static void cleanup(void)
+{
+ if (fd_zero > 0)
+ SAFE_CLOSE(fd_zero);
+
+ if (fd_full > 0)
+ SAFE_CLOSE(fd_full);
+}
+
+static struct tst_test test = {
+ .test = verify_splice,
+ .tcnt = 9,
+ .setup = setup,
+ .cleanup = cleanup,
+ .min_kver = "6.7",
+};
--
2.43.2