scftorture: Count single_rpc offline failures in statistics outputgrafted

scf_torture_stats_print() aggregates each invoker thread's counters
into a local scf_statistics structure before printing, but the
n_single_rpc_ofl field is missing from the aggregation loop.  As a
result, the "single_rpc_ofl" value printed in the statistics line is
always zero, even when smp_call_function_single() invocations for the
RPC test have failed due to offline CPUs and been counted by the
invoker threads.

Add the missing accumulation so that the printed value reflects the
actual counts.

Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

8 files changed, 217 insertions, 0 deletions

diff --git a/tools/testing/selftests/splice/.gitignore b/tools/testing/selftests/splice/.gitignore
new file mode 100644
index 000000000..be8266f5d
--- /dev/null
+++ b/tools/testing/selftests/splice/.gitignore
@@ -0,0 +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
new file mode 100644
index 000000000..541cd826d
--- /dev/null
+++ b/tools/testing/selftests/splice/Makefile
@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0
+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 000000000..058c92836
--- /dev/null
+++ b/tools/testing/selftests/splice/config
@@ -0,0 +1 @@
+CONFIG_TEST_LKM=m
diff --git a/tools/testing/selftests/splice/default_file_splice_read.c b/tools/testing/selftests/splice/default_file_splice_read.c
new file mode 100644
index 000000000..a3c6e5672
--- /dev/null
+++ b/tools/testing/selftests/splice/default_file_splice_read.c
@@ -0,0 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0
+#define _GNU_SOURCE
+#include <fcntl.h>
+
+int main(int argc, char **argv)
+{
+        splice(0, 0, 1, 0, 1<<30, 0);
+	return 0;
+}
diff --git a/tools/testing/selftests/splice/default_file_splice_read.sh b/tools/testing/selftests/splice/default_file_splice_read.sh
new file mode 100755
index 000000000..490db5a2e
--- /dev/null
+++ b/tools/testing/selftests/splice/default_file_splice_read.sh
@@ -0,0 +1,8 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+n=`./default_file_splice_read </dev/null | wc -c`
+
+test "$n" = 0 && exit 0
+
+echo "default_file_splice_read broken: leaked $n"
+exit 1
diff --git a/tools/testing/selftests/splice/settings b/tools/testing/selftests/splice/settings
new file mode 100644
index 000000000..89cedfc0d
--- /dev/null
+++ b/tools/testing/selftests/splice/settings
@@ -0,0 +1 @@
+timeout=5
diff --git a/tools/testing/selftests/splice/short_splice_read.sh b/tools/testing/selftests/splice/short_splice_read.sh
new file mode 100755
index 000000000..4710e09f4
--- /dev/null
+++ b/tools/testing/selftests/splice/short_splice_read.sh
@@ -0,0 +1,133 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+#
+# Test for mishandling of splice() on pseudofilesystems, which should catch
+# bugs like 11990a5bd7e5 ("module: Correctly truncate sysfs sections output")
+#
+# Since splice fallback was removed as part of the set_fs() rework, many of these
+# tests expect to fail now. See https://lore.kernel.org/lkml/202009181443.C2179FB@keescook/
+set -e
+
+DIR=$(dirname "$0")
+
+ret=0
+
+expect_success()
+{
+	title="$1"
+	shift
+
+	echo "" >&2
+	echo "$title ..." >&2
+
+	set +e
+	"$@"
+	rc=$?
+	set -e
+
+	case "$rc" in
+	0)
+		echo "ok: $title succeeded" >&2
+		;;
+	1)
+		echo "FAIL: $title should work" >&2
+		ret=$(( ret + 1 ))
+		;;
+	*)
+		echo "FAIL: something else went wrong" >&2
+		ret=$(( ret + 1 ))
+		;;
+	esac
+}
+
+expect_failure()
+{
+	title="$1"
+	shift
+
+	echo "" >&2
+	echo "$title ..." >&2
+
+	set +e
+	"$@"
+	rc=$?
+	set -e
+
+	case "$rc" in
+	0)
+		echo "FAIL: $title unexpectedly worked" >&2
+		ret=$(( ret + 1 ))
+		;;
+	1)
+		echo "ok: $title correctly failed" >&2
+		;;
+	*)
+		echo "FAIL: something else went wrong" >&2
+		ret=$(( ret + 1 ))
+		;;
+	esac
+}
+
+do_splice()
+{
+	filename="$1"
+	bytes="$2"
+	expected="$3"
+	report="$4"
+
+	out=$("$DIR"/splice_read "$filename" "$bytes" | cat)
+	if [ "$out" = "$expected" ] ; then
+		echo "      matched $report" >&2
+		return 0
+	else
+		echo "      no match: '$out' vs $report" >&2
+		return 1
+	fi
+}
+
+test_splice()
+{
+	filename="$1"
+
+	echo "  checking $filename ..." >&2
+
+	full=$(cat "$filename")
+	rc=$?
+	if [ $rc -ne 0 ] ; then
+		return 2
+	fi
+
+	two=$(echo "$full" | grep -m1 . | cut -c-2)
+
+	# Make sure full splice has the same contents as a standard read.
+	echo "    splicing 4096 bytes ..." >&2
+	if ! do_splice "$filename" 4096 "$full" "full read" ; then
+		return 1
+	fi
+
+	# Make sure a partial splice see the first two characters.
+	echo "    splicing 2 bytes ..." >&2
+	if ! do_splice "$filename" 2 "$two" "'$two'" ; then
+		return 1
+	fi
+
+	return 0
+}
+
+### /proc/$pid/ has no splice interface; these should all fail.
+expect_failure "proc_single_open(), seq_read() splice" test_splice /proc/$$/limits
+expect_failure "special open(), seq_read() splice" test_splice /proc/$$/comm
+
+### /proc/sys/ has a splice interface; these should all succeed.
+expect_success "proc_handler: proc_dointvec_minmax() splice" test_splice /proc/sys/fs/nr_open
+expect_success "proc_handler: proc_dostring() splice" test_splice /proc/sys/kernel/modprobe
+expect_success "proc_handler: special read splice" test_splice /proc/sys/kernel/version
+
+### /sys/ has no splice interface; these should all fail.
+if ! [ -d /sys/module/test_module/sections ] ; then
+	expect_success "test_module kernel module load" modprobe test_module
+fi
+expect_success "kernfs attr splice" test_splice /sys/module/test_module/coresize
+expect_success "kernfs binattr splice" 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 000000000..46dae6a25
--- /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;
+}