linux-kselftest-4.8-rc1-update

This update for Kselftest adds:
 
 - a few fixes to existing tests
 - new media tests for testing driver unbind, and device removal
   paths while an user application is actively making system calls
   and ioctls.
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Merge tag 'linux-kselftest-4.8-rc1-update' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull kselftest updates from Shuah Khan:
 "This contains new tests and fixes:

   - a few fixes to existing tests

   - new media tests for testing driver unbind, and device removal paths
     while an user application is actively making system calls and
     ioctls"

* tag 'linux-kselftest-4.8-rc1-update' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  selftests: media_tests add a new video device test
  selftests: media_tests - Add media_device_open to .gitignore
  selftests: add media controller regression test scripts and document
  selftests: add media_device_open test
  selftests: media_device_test change it to randomize loop count
  selftests/vm: Don't mlockall MCL_CURRENT in on-fault-limit test
  selftests/vm: write strlen length instead of sizeof to nr_hugepages
  selftests/lib: set printf.sh executable

tools/testing/selftests/media_tests/.gitignore

@@ -1 +1,3 @@
 media_device_test
+media_device_open
+video_device_test

tools/testing/selftests/media_tests/Makefile

@@ -1,7 +1,7 @@
-TEST_PROGS := media_device_test
+TEST_PROGS := media_device_test media_device_open video_device_test
 all: $(TEST_PROGS)
 
 include ../lib.mk
 
 clean:
-	rm -fr media_device_test
+	rm -fr media_device_test media_device_open video_device_test

tools/testing/selftests/media_tests/bind_unbind_sample.sh

@@ -0,0 +1,12 @@
+#!/bin/bash
+# Find device number in /sys/bus/usb/drivers/drivername
+# Edit this file to update the driver numer and name
+# Example test for uvcvideo driver
+#i=0
+# while :; do
+#  i=$((i+1))
+#  echo 1-5:1.0 > /sys/bus/usb/drivers/uvcvideo/unbind;
+#  echo 1-5:1.0 > /sys/bus/usb/drivers/uvcvideo/bind;
+#  clear
+#	echo $i
+#done

tools/testing/selftests/media_tests/media_device_open.c

@@ -0,0 +1,81 @@
+/*
+ * media_device_open.c - Media Controller Device Open Test
+ *
+ * Copyright (c) 2016 Shuah Khan <shuahkh@osg.samsung.com>
+ * Copyright (c) 2016 Samsung Electronics Co., Ltd.
+ *
+ * This file is released under the GPLv2.
+ */
+
+/*
+ * This file adds a test for Media Controller API.
+ * This test should be run as root and should not be
+ * included in the Kselftest run. This test should be
+ * run when hardware and driver that makes use Media
+ * Controller API are present in the system.
+ *
+ * This test opens user specified Media Device and calls
+ * MEDIA_IOC_DEVICE_INFO ioctl, closes the file, and exits.
+ *
+ * Usage:
+ *	sudo ./media_device_open -d /dev/mediaX
+ *
+ *	Run this test is a loop and run bind/unbind on the driver.
+*/
+
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <string.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <linux/media.h>
+
+int main(int argc, char **argv)
+{
+	int opt;
+	char media_device[256];
+	int count = 0;
+	struct media_device_info mdi;
+	int ret;
+	int fd;
+
+	if (argc < 2) {
+		printf("Usage: %s [-d </dev/mediaX>]\n", argv[0]);
+		exit(-1);
+	}
+
+	/* Process arguments */
+	while ((opt = getopt(argc, argv, "d:")) != -1) {
+		switch (opt) {
+		case 'd':
+			strncpy(media_device, optarg, sizeof(media_device) - 1);
+			media_device[sizeof(media_device)-1] = '\0';
+			break;
+		default:
+			printf("Usage: %s [-d </dev/mediaX>]\n", argv[0]);
+			exit(-1);
+		}
+	}
+
+	if (getuid() != 0) {
+		printf("Please run the test as root - Exiting.\n");
+		exit(-1);
+	}
+
+	/* Open Media device and keep it open */
+	fd = open(media_device, O_RDWR);
+	if (fd == -1) {
+		printf("Media Device open errno %s\n", strerror(errno));
+		exit(-1);
+	}
+
+	ret = ioctl(fd, MEDIA_IOC_DEVICE_INFO, &mdi);
+	if (ret < 0)
+		printf("Media Device Info errno %s\n", strerror(errno));
+	else
+		printf("Media device model %s driver %s\n",
+			mdi.model, mdi.driver);
+}

tools/testing/selftests/media_tests/media_device_test.c

@@ -1,5 +1,5 @@
 /*
- * media_devkref_test.c - Media Controller Device Kref API Test
+ * media_device_test.c - Media Controller Device ioctl loop Test
  *
  * Copyright (c) 2016 Shuah Khan <shuahkh@osg.samsung.com>
  * Copyright (c) 2016 Samsung Electronics Co., Ltd.
@@ -35,13 +35,14 @@
 #include <fcntl.h>
 #include <sys/ioctl.h>
 #include <sys/stat.h>
+#include <time.h>
 #include <linux/media.h>
 
 int main(int argc, char **argv)
 {
 	int opt;
 	char media_device[256];
-	int count = 0;
+	int count;
 	struct media_device_info mdi;
 	int ret;
 	int fd;
@@ -69,6 +70,10 @@ int main(int argc, char **argv)
 		exit(-1);
 	}
 
+	/* Generate random number of interations */
+	srand((unsigned int) time(NULL));
+	count = rand();
+
 	/* Open Media device and keep it open */
 	fd = open(media_device, O_RDWR);
 	if (fd == -1) {
@@ -82,14 +87,16 @@ int main(int argc, char **argv)
 	       "other Oops in the dmesg. Enable KaSan kernel\n"
 	       "config option for use-after-free error detection.\n\n");
 
-	while (count < 100) {
+	printf("Running test for %d iternations\n", count);
+
+	while (count > 0) {
 		ret = ioctl(fd, MEDIA_IOC_DEVICE_INFO, &mdi);
 		if (ret < 0)
 			printf("Media Device Info errno %s\n", strerror(errno));
 		else
-			printf("Media device model %s driver %s\n",
+			printf("Media device model %s driver %s - count %d\n",
-				mdi.model, mdi.driver);
+				mdi.model, mdi.driver, count);
 		sleep(10);
-		count++;
+		count--;
 	}
 }

tools/testing/selftests/media_tests/open_loop_test.sh

@@ -0,0 +1,10 @@
+#!/bin/bash
+ i=0
+file=/dev/media$1
+ while :; do
+  echo $file
+  i=$((i+1))
+  R=$(./media_device_open -d $file);
+ # clear
+  echo -e "Loop $i\n$R"
+ done

tools/testing/selftests/media_tests/regression_test.txt

@@ -0,0 +1,43 @@
+Testing for regressions in Media Controller API register, ioctl, syscall,
+and unregister paths. There have a few problems that result in user-after
+free on media_device, media_devnode, and cdev pointers when the driver is
+unbound while ioctl is in progress.
+
+Test Procedure:
+
+Run bin/unbind loop while ioctls are in progress.
+Run rmmod and modprobe.
+Disconnect the device.
+
+Setup:
+
+Build media_device_test
+cd tools/testing/selftests/media_tests
+make
+
+Regressions test for cdev user-after free error on /dev/mediaX when driver
+is unbound:
+
+Start media_device_test to regression test media devnode dynamic alloc
+and cdev user-after-free fixes. This opens media dev files and sits in
+a loop running media ioctl MEDIA_IOC_DEVICE_INFO command once every 10
+seconds. The idea is when device file goes away, media devnode and cdev
+should stick around until this test exits.
+
+The test for a random number of iterations or until user kills it with a
+sleep 10 in between the ioctl calls.
+
+sudo ./media_device_test -d /dev/mediaX
+
+Regression test for media_devnode unregister race with ioctl_syscall:
+
+Start 6 open_loop_test.sh tests with different /dev/mediaX files. When
+device file goes away after unbind, device file name changes. Start the
+test with possible device names. If we start with /dev/media0 for example,
+after unbind, /dev/media1 or /dev/media2 could get created. The idea is
+keep ioctls going while bind/unbind runs.
+
+Copy bind_unbind_sample.txt and make changes to specify the driver name
+and number to run bind and unbind. Start the bind_unbind.sh
+
+Run dmesg looking for any user-after free errors or mutex lock errors.

tools/testing/selftests/media_tests/video_device_test.c

@@ -0,0 +1,100 @@
+/*
+ * video_device_test - Video Device Test
+ *
+ * Copyright (c) 2016 Shuah Khan <shuahkh@osg.samsung.com>
+ * Copyright (c) 2016 Samsung Electronics Co., Ltd.
+ *
+ * This file is released under the GPLv2.
+ */
+
+/*
+ * This file adds a test for Video Device. This test should not be included
+ * in the Kselftest run. This test should be run when hardware and driver
+ * that makes use of V4L2 API is present.
+ *
+ * This test opens user specified Video Device and calls video ioctls in a
+ * loop once every 10 seconds.
+ *
+ * Usage:
+ *	sudo ./video_device_test -d /dev/videoX
+ *
+ *	While test is running, remove the device or unbind the driver and
+ *	ensure there are no use after free errors and other Oops in the
+ *	dmesg.
+ *	When possible, enable KaSan kernel config option for use-after-free
+ *	error detection.
+*/
+
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <string.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <time.h>
+#include <linux/videodev2.h>
+
+int main(int argc, char **argv)
+{
+	int opt;
+	char video_dev[256];
+	int count;
+	struct v4l2_tuner vtuner;
+	struct v4l2_capability vcap;
+	int ret;
+	int fd;
+
+	if (argc < 2) {
+		printf("Usage: %s [-d </dev/videoX>]\n", argv[0]);
+		exit(-1);
+	}
+
+	/* Process arguments */
+	while ((opt = getopt(argc, argv, "d:")) != -1) {
+		switch (opt) {
+		case 'd':
+			strncpy(video_dev, optarg, sizeof(video_dev) - 1);
+			video_dev[sizeof(video_dev)-1] = '\0';
+			break;
+		default:
+			printf("Usage: %s [-d </dev/videoX>]\n", argv[0]);
+			exit(-1);
+		}
+	}
+
+	/* Generate random number of interations */
+	srand((unsigned int) time(NULL));
+	count = rand();
+
+	/* Open Video device and keep it open */
+	fd = open(video_dev, O_RDWR);
+	if (fd == -1) {
+		printf("Video Device open errno %s\n", strerror(errno));
+		exit(-1);
+	}
+
+	printf("\nNote:\n"
+	       "While test is running, remove the device or unbind\n"
+	       "driver and ensure there are no use after free errors\n"
+	       "and other Oops in the dmesg. When possible, enable KaSan\n"
+	       "kernel config option for use-after-free error detection.\n\n");
+
+	while (count > 0) {
+		ret = ioctl(fd, VIDIOC_QUERYCAP, &vcap);
+		if (ret < 0)
+			printf("VIDIOC_QUERYCAP errno %s\n", strerror(errno));
+		else
+			printf("Video device driver %s\n", vcap.driver);
+
+		ret = ioctl(fd, VIDIOC_G_TUNER, &vtuner);
+		if (ret < 0)
+			printf("VIDIOC_G_TUNER, errno %s\n", strerror(errno));
+		else
+			printf("type %d rangelow %d rangehigh %d\n",
+				vtuner.type, vtuner.rangelow, vtuner.rangehigh);
+		sleep(10);
+		count--;
+	}
+}

tools/testing/selftests/vm/compaction_test.c

@@ -101,7 +101,7 @@ int check_compaction(unsigned long mem_free, unsigned int hugepage_size)
 
 	/* Start with the initial condition of 0 huge pages*/
 	if (write(fd, "0", sizeof(char)) != sizeof(char)) {
-		perror("Failed to write to /proc/sys/vm/nr_hugepages\n");
+		perror("Failed to write 0 to /proc/sys/vm/nr_hugepages\n");
 		goto close_fd;
 	}
 
@@ -110,14 +110,14 @@ int check_compaction(unsigned long mem_free, unsigned int hugepage_size)
 	/* Request a large number of huge pages. The Kernel will allocate
 	   as much as it can */
 	if (write(fd, "100000", (6*sizeof(char))) != (6*sizeof(char))) {
-		perror("Failed to write to /proc/sys/vm/nr_hugepages\n");
+		perror("Failed to write 100000 to /proc/sys/vm/nr_hugepages\n");
 		goto close_fd;
 	}
 
 	lseek(fd, 0, SEEK_SET);
 
 	if (read(fd, nr_hugepages, sizeof(nr_hugepages)) <= 0) {
-		perror("Failed to read from /proc/sys/vm/nr_hugepages\n");
+		perror("Failed to re-read from /proc/sys/vm/nr_hugepages\n");
 		goto close_fd;
 	}
 
@@ -138,7 +138,7 @@ int check_compaction(unsigned long mem_free, unsigned int hugepage_size)
 
 	if (write(fd, initial_nr_hugepages, strlen(initial_nr_hugepages))
 	    != strlen(initial_nr_hugepages)) {
-		perror("Failed to write to /proc/sys/vm/nr_hugepages\n");
+		perror("Failed to write value to /proc/sys/vm/nr_hugepages\n");
 		goto close_fd;
 	}
 

tools/testing/selftests/vm/on-fault-limit.c

@@ -20,7 +20,7 @@ static int test_limit(void)
 		return ret;
 	}
 
-	if (mlockall(MCL_CURRENT | MCL_ONFAULT | MCL_FUTURE)) {
+	if (mlockall(MCL_ONFAULT | MCL_FUTURE)) {
 		perror("mlockall");
 		return ret;
 	}