In order to help catch regressions in splice vs read behavior in certain
special files, test a few with various different kinds of internal
kernel helpers.
Cc: Shuah Khan <shuah@xxxxxxxxxx>
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
tools/testing/selftests/splice/.gitignore | 1 +
tools/testing/selftests/splice/Makefile | 4 +-
tools/testing/selftests/splice/config | 1 +
tools/testing/selftests/splice/settings | 1 +
.../selftests/splice/short_splice_read.sh | 56 ++++++++++++++++++
tools/testing/selftests/splice/splice_read.c | 57 +++++++++++++++++++
6 files changed, 118 insertions(+), 2 deletions(-)
create mode 100644 tools/testing/selftests/splice/config
create mode 100644 tools/testing/selftests/splice/settings
create mode 100755 tools/testing/selftests/splice/short_splice_read.sh
create mode 100644 tools/testing/selftests/splice/splice_read.c
diff --git a/tools/testing/selftests/splice/.gitignore b/tools/testing/selftests/splice/.gitignore
index d5a2da428752..be8266f5d04c 100644
--- a/tools/testing/selftests/splice/.gitignore
+++ b/tools/testing/selftests/splice/.gitignore
@@ -1,2 +1,3 @@
# SPDX-License-Identifier: GPL-2.0-only
default_file_splice_read
+splice_read
diff --git a/tools/testing/selftests/splice/Makefile b/tools/testing/selftests/splice/Makefile
index e519b159b60d..541cd826d5a5 100644
--- a/tools/testing/selftests/splice/Makefile
+++ b/tools/testing/selftests/splice/Makefile
@@ -1,5 +1,5 @@
# SPDX-License-Identifier: GPL-2.0
-TEST_PROGS := default_file_splice_read.sh
-TEST_GEN_PROGS_EXTENDED := default_file_splice_read
+TEST_PROGS := default_file_splice_read.sh short_splice_read.sh
+TEST_GEN_PROGS_EXTENDED := default_file_splice_read splice_read
include ../lib.mk
diff --git a/tools/testing/selftests/splice/config b/tools/testing/selftests/splice/config
new file mode 100644
index 000000000000..058c928368b8
--- /dev/null
+++ b/tools/testing/selftests/splice/config
@@ -0,0 +1 @@
+CONFIG_TEST_LKM=m
diff --git a/tools/testing/selftests/splice/settings b/tools/testing/selftests/splice/settings
new file mode 100644
index 000000000000..89cedfc0d12b
--- /dev/null
+++ b/tools/testing/selftests/splice/settings
@@ -0,0 +1 @@
+timeout=5
diff --git a/tools/testing/selftests/splice/short_splice_read.sh b/tools/testing/selftests/splice/short_splice_read.sh
new file mode 100755
index 000000000000..7810d3589d9a
--- /dev/null
+++ b/tools/testing/selftests/splice/short_splice_read.sh
@@ -0,0 +1,56 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+set -e
+
+ret=0
+
+do_splice()
+{
+ filename="$1"
+ bytes="$2"
+ expected="$3"
+
+ out=$(./splice_read "$filename" "$bytes" | cat)
+ if [ "$out" = "$expected" ] ; then
+ echo "ok: $filename $bytes"
+ else
+ echo "FAIL: $filename $bytes"
+ ret=1
+ fi
+}
+
+test_splice()
+{
+ filename="$1"
+
+ full=$(cat "$filename")
+ two=$(echo "$full" | grep -m1 . | cut -c-2)
+
+ # Make sure full splice has the same contents as a standard read.
+ do_splice "$filename" 4096 "$full"
+
+ # Make sure a partial splice see the first two characters.
+ do_splice "$filename" 2 "$two"
+}
+
+# proc_single_open(), seq_read()
+test_splice /proc/$$/limits
+# special open, seq_read()
+test_splice /proc/$$/comm
+
+# proc_handler, proc_dointvec_minmax
+test_splice /proc/sys/fs/nr_open
+# proc_handler, proc_dostring
+test_splice /proc/sys/kernel/modprobe
+# proc_handler, special read
+test_splice /proc/sys/kernel/version
+
+if ! [ -d /sys/module/test_module/sections ] ; then
+ modprobe test_module
+fi
+# kernfs, attr
+test_splice /sys/module/test_module/coresize
+# kernfs, binattr
+test_splice /sys/module/test_module/sections/.init.text
+
+exit $ret
diff --git a/tools/testing/selftests/splice/splice_read.c b/tools/testing/selftests/splice/splice_read.c
new file mode 100644
index 000000000000..46dae6a25cfb
--- /dev/null
+++ b/tools/testing/selftests/splice/splice_read.c
@@ -0,0 +1,57 @@
+// SPDX-License-Identifier: GPL-2.0
+#define _GNU_SOURCE
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+int main(int argc, char *argv[])
+{
+ int fd;
+ size_t size;
+ ssize_t spliced;
+
+ if (argc < 2) {
+ fprintf(stderr, "Usage: %s INPUT [BYTES]\n", argv[0]);
+ return EXIT_FAILURE;
+ }
+
+ fd = open(argv[1], O_RDONLY);
+ if (fd < 0) {
+ perror(argv[1]);
+ return EXIT_FAILURE;
+ }
+
+ if (argc == 3)
+ size = atol(argv[2]);
+ else {
+ struct stat statbuf;
+
+ if (fstat(fd, &statbuf) < 0) {
+ perror(argv[1]);
+ return EXIT_FAILURE;
+ }
+
+ if (statbuf.st_size > INT_MAX) {
+ fprintf(stderr, "%s: Too big\n", argv[1]);
+ return EXIT_FAILURE;
+ }
+
+ size = statbuf.st_size;
+ }
+
+ /* splice(2) file to stdout. */
+ spliced = splice(fd, NULL, STDOUT_FILENO, NULL,
+ size, SPLICE_F_MOVE);
+ if (spliced < 0) {
+ perror("splice");
+ return EXIT_FAILURE;
+ }
+
+ close(fd);
+ return EXIT_SUCCESS;
+}
--
2.25.1
