Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

8 files changed, 458 insertions, 0 deletions

diff --git a/tools/testing/selftests/zram/.gitignore b/tools/testing/selftests/zram/.gitignore
new file mode 100644
index 000000000..088cd9bad
--- /dev/null
+++ b/tools/testing/selftests/zram/.gitignore
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+err.log
diff --git a/tools/testing/selftests/zram/Makefile b/tools/testing/selftests/zram/Makefile
new file mode 100644
index 000000000..7f78eb1b5
--- /dev/null
+++ b/tools/testing/selftests/zram/Makefile
@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: GPL-2.0
+all:
+
+TEST_PROGS := zram.sh
+TEST_FILES := zram01.sh zram02.sh zram_lib.sh
+EXTRA_CLEAN := err.log
+
+include ../lib.mk
+
diff --git a/tools/testing/selftests/zram/README b/tools/testing/selftests/zram/README
new file mode 100644
index 000000000..82921c756
--- /dev/null
+++ b/tools/testing/selftests/zram/README
@@ -0,0 +1,39 @@
+zram: Compressed RAM based block devices
+----------------------------------------
+* Introduction
+
+The zram module creates RAM based block devices named /dev/zram<id>
+(<id> = 0, 1, ...). Pages written to these disks are compressed and stored
+in memory itself. These disks allow very fast I/O and compression provides
+good amounts of memory savings. Some of the usecases include /tmp storage,
+use as swap disks, various caches under /var and maybe many more :)
+
+Statistics for individual zram devices are exported through sysfs nodes at
+/sys/block/zram<id>/
+
+Kconfig required:
+CONFIG_ZRAM=y
+CONFIG_CRYPTO_LZ4=y
+CONFIG_ZSMALLOC=y
+
+ZRAM Testcases
+--------------
+zram_lib.sh: create library with initialization/cleanup functions
+zram.sh: For sanity check of CONFIG_ZRAM and to run zram01 and zram02
+
+Two functional tests: zram01 and zram02:
+zram01.sh: creates general purpose ram disks with ext4 filesystems
+zram02.sh: creates block device for swap
+
+Commands required for testing:
+ - bc
+ - dd
+ - free
+ - awk
+ - mkswap
+ - swapon
+ - swapoff
+ - mkfs/ mkfs.ext4
+
+For more information please refer:
+kernel-source-tree/Documentation/admin-guide/blockdev/zram.rst
diff --git a/tools/testing/selftests/zram/config b/tools/testing/selftests/zram/config
new file mode 100644
index 000000000..e0cc47e2c
--- /dev/null
+++ b/tools/testing/selftests/zram/config
@@ -0,0 +1,2 @@
+CONFIG_ZSMALLOC=y
+CONFIG_ZRAM=m
diff --git a/tools/testing/selftests/zram/zram.sh b/tools/testing/selftests/zram/zram.sh
new file mode 100755
index 000000000..b0b91d9b0
--- /dev/null
+++ b/tools/testing/selftests/zram/zram.sh
@@ -0,0 +1,18 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+TCID="zram.sh"
+
+. ./zram_lib.sh
+
+run_zram () {
+echo "--------------------"
+echo "running zram tests"
+echo "--------------------"
+./zram01.sh
+echo ""
+./zram02.sh
+}
+
+check_prereqs
+
+run_zram
diff --git a/tools/testing/selftests/zram/zram01.sh b/tools/testing/selftests/zram/zram01.sh
new file mode 100755
index 000000000..8f4affe34
--- /dev/null
+++ b/tools/testing/selftests/zram/zram01.sh
@@ -0,0 +1,75 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0-or-later
+# Copyright (c) 2015 Oracle and/or its affiliates. All Rights Reserved.
+#
+# Test creates several zram devices with different filesystems on them.
+# It fills each device with zeros and checks that compression works.
+#
+# Author: Alexey Kodanev <alexey.kodanev@oracle.com>
+# Modified: Naresh Kamboju <naresh.kamboju@linaro.org>
+
+TCID="zram01"
+ERR_CODE=0
+
+. ./zram_lib.sh
+
+# Test will create the following number of zram devices:
+dev_num=1
+# This is a list of parameters for zram devices.
+# Number of items must be equal to 'dev_num' parameter.
+zram_max_streams="2"
+
+# The zram sysfs node 'disksize' value can be either in bytes,
+# or you can use mem suffixes. But in some old kernels, mem
+# suffixes are not supported, for example, in RHEL6.6GA's kernel
+# layer, it uses strict_strtoull() to parse disksize which does
+# not support mem suffixes, in some newer kernels, they use
+# memparse() which supports mem suffixes. So here we just use
+# bytes to make sure everything works correctly.
+zram_sizes="2097152" # 2MB
+zram_mem_limits="2M"
+zram_filesystems="ext4"
+zram_algs="lzo"
+
+zram_fill_fs()
+{
+	for i in $(seq $dev_start $dev_end); do
+		echo "fill zram$i..."
+		local b=0
+		while [ true ]; do
+			dd conv=notrunc if=/dev/zero of=zram${i}/file \
+				oflag=append count=1 bs=1024 status=none \
+				> /dev/null 2>&1 || break
+			b=$(($b + 1))
+		done
+		echo "zram$i can be filled with '$b' KB"
+
+		local mem_used_total=`awk '{print $3}' "/sys/block/zram$i/mm_stat"`
+		local v=$((100 * 1024 * $b / $mem_used_total))
+		if [ "$v" -lt 100 ]; then
+			 echo "FAIL compression ratio: 0.$v:1"
+			 ERR_CODE=-1
+			 return
+		fi
+
+		echo "zram compression ratio: $(echo "scale=2; $v / 100 " | bc):1: OK"
+	done
+}
+
+check_prereqs
+zram_load
+zram_max_streams
+zram_compress_alg
+zram_set_disksizes
+zram_set_memlimit
+zram_makefs
+zram_mount
+
+zram_fill_fs
+zram_cleanup
+
+if [ $ERR_CODE -ne 0 ]; then
+	echo "$TCID : [FAIL]"
+else
+	echo "$TCID : [PASS]"
+fi
diff --git a/tools/testing/selftests/zram/zram02.sh b/tools/testing/selftests/zram/zram02.sh
new file mode 100755
index 000000000..2418b0c4e
--- /dev/null
+++ b/tools/testing/selftests/zram/zram02.sh
@@ -0,0 +1,44 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0-or-later
+# Copyright (c) 2015 Oracle and/or its affiliates. All Rights Reserved.
+#
+# Test checks that we can create swap zram device.
+#
+# Author: Alexey Kodanev <alexey.kodanev@oracle.com>
+# Modified: Naresh Kamboju <naresh.kamboju@linaro.org>
+
+TCID="zram02"
+ERR_CODE=0
+
+. ./zram_lib.sh
+
+# Test will create the following number of zram devices:
+dev_num=1
+# This is a list of parameters for zram devices.
+# Number of items must be equal to 'dev_num' parameter.
+zram_max_streams="2"
+
+# The zram sysfs node 'disksize' value can be either in bytes,
+# or you can use mem suffixes. But in some old kernels, mem
+# suffixes are not supported, for example, in RHEL6.6GA's kernel
+# layer, it uses strict_strtoull() to parse disksize which does
+# not support mem suffixes, in some newer kernels, they use
+# memparse() which supports mem suffixes. So here we just use
+# bytes to make sure everything works correctly.
+zram_sizes="1048576" # 1M
+zram_mem_limits="1M"
+
+check_prereqs
+zram_load
+zram_max_streams
+zram_set_disksizes
+zram_set_memlimit
+zram_makeswap
+zram_swapoff
+zram_cleanup
+
+if [ $ERR_CODE -ne 0 ]; then
+	echo "$TCID : [FAIL]"
+else
+	echo "$TCID : [PASS]"
+fi
diff --git a/tools/testing/selftests/zram/zram_lib.sh b/tools/testing/selftests/zram/zram_lib.sh
new file mode 100755
index 000000000..0d44d8388
--- /dev/null
+++ b/tools/testing/selftests/zram/zram_lib.sh
@@ -0,0 +1,269 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0-or-later
+# Copyright (c) 2015 Oracle and/or its affiliates. All Rights Reserved.
+#
+# Author: Alexey Kodanev <alexey.kodanev@oracle.com>
+# Modified: Naresh Kamboju <naresh.kamboju@linaro.org>
+
+dev_makeswap=-1
+dev_mounted=-1
+dev_start=0
+dev_end=-1
+module_load=-1
+sys_control=-1
+# Kselftest framework requirement - SKIP code is 4.
+ksft_skip=4
+kernel_version=`uname -r | cut -d'.' -f1,2`
+kernel_major=${kernel_version%.*}
+kernel_minor=${kernel_version#*.}
+
+trap INT
+
+check_prereqs()
+{
+	local msg="skip all tests:"
+	local uid=$(id -u)
+
+	if [ $uid -ne 0 ]; then
+		echo $msg must be run as root >&2
+		exit $ksft_skip
+	fi
+}
+
+kernel_gte()
+{
+	major=${1%.*}
+	minor=${1#*.}
+
+	if [ $kernel_major -gt $major ]; then
+		return 0
+	elif [ $kernel_major -eq $major ] && [ $kernel_minor -ge $minor ]; then
+		return 0
+	fi
+
+	return 1
+}
+
+zram_cleanup()
+{
+	echo "zram cleanup"
+	local i=
+	for i in $(seq $dev_start $dev_makeswap); do
+		swapoff /dev/zram$i
+	done
+
+	for i in $(seq $dev_start $dev_mounted); do
+		umount /dev/zram$i
+	done
+
+	for i in $(seq $dev_start $dev_end); do
+		echo 1 > /sys/block/zram${i}/reset
+		rm -rf zram$i
+	done
+
+	if [ $sys_control -eq 1 ]; then
+		for i in $(seq $dev_start $dev_end); do
+			echo $i > /sys/class/zram-control/hot_remove
+		done
+	fi
+
+	if [ $module_load -eq 1 ]; then
+		rmmod zram > /dev/null 2>&1
+	fi
+}
+
+zram_load()
+{
+	echo "create '$dev_num' zram device(s)"
+
+	# zram module loaded, new kernel
+	if [ -d "/sys/class/zram-control" ]; then
+		echo "zram modules already loaded, kernel supports" \
+			"zram-control interface"
+		dev_start=$(ls /dev/zram* | wc -w)
+		dev_end=$(($dev_start + $dev_num - 1))
+		sys_control=1
+
+		for i in $(seq $dev_start $dev_end); do
+			cat /sys/class/zram-control/hot_add > /dev/null
+		done
+
+		echo "all zram devices (/dev/zram$dev_start~$dev_end" \
+			"successfully created"
+		return 0
+	fi
+
+	# detect old kernel or built-in
+	modprobe zram num_devices=$dev_num
+	if [ ! -d "/sys/class/zram-control" ]; then
+		if grep -q '^zram' /proc/modules; then
+			rmmod zram > /dev/null 2>&1
+			if [ $? -ne 0 ]; then
+				echo "zram module is being used on old kernel" \
+					"without zram-control interface"
+				exit $ksft_skip
+			fi
+		else
+			echo "test needs CONFIG_ZRAM=m on old kernel without" \
+				"zram-control interface"
+			exit $ksft_skip
+		fi
+		modprobe zram num_devices=$dev_num
+	fi
+
+	module_load=1
+	dev_end=$(($dev_num - 1))
+	echo "all zram devices (/dev/zram0~$dev_end) successfully created"
+}
+
+zram_max_streams()
+{
+	echo "set max_comp_streams to zram device(s)"
+
+	kernel_gte 4.7
+	if [ $? -eq 0 ]; then
+		echo "The device attribute max_comp_streams was"\
+		               "deprecated in 4.7"
+		return 0
+	fi
+
+	local i=$dev_start
+	for max_s in $zram_max_streams; do
+		local sys_path="/sys/block/zram${i}/max_comp_streams"
+		echo $max_s > $sys_path || \
+			echo "FAIL failed to set '$max_s' to $sys_path"
+		sleep 1
+		local max_streams=$(cat $sys_path)
+
+		[ "$max_s" -ne "$max_streams" ] && \
+			echo "FAIL can't set max_streams '$max_s', get $max_stream"
+
+		i=$(($i + 1))
+		echo "$sys_path = '$max_streams'"
+	done
+
+	echo "zram max streams: OK"
+}
+
+zram_compress_alg()
+{
+	echo "test that we can set compression algorithm"
+
+	local i=$dev_start
+	local algs=$(cat /sys/block/zram${i}/comp_algorithm)
+	echo "supported algs: $algs"
+
+	for alg in $zram_algs; do
+		local sys_path="/sys/block/zram${i}/comp_algorithm"
+		echo "$alg" >	$sys_path || \
+			echo "FAIL can't set '$alg' to $sys_path"
+		i=$(($i + 1))
+		echo "$sys_path = '$alg'"
+	done
+
+	echo "zram set compression algorithm: OK"
+}
+
+zram_set_disksizes()
+{
+	echo "set disk size to zram device(s)"
+	local i=$dev_start
+	for ds in $zram_sizes; do
+		local sys_path="/sys/block/zram${i}/disksize"
+		echo "$ds" >	$sys_path || \
+			echo "FAIL can't set '$ds' to $sys_path"
+
+		i=$(($i + 1))
+		echo "$sys_path = '$ds'"
+	done
+
+	echo "zram set disksizes: OK"
+}
+
+zram_set_memlimit()
+{
+	echo "set memory limit to zram device(s)"
+
+	local i=$dev_start
+	for ds in $zram_mem_limits; do
+		local sys_path="/sys/block/zram${i}/mem_limit"
+		echo "$ds" >	$sys_path || \
+			echo "FAIL can't set '$ds' to $sys_path"
+
+		i=$(($i + 1))
+		echo "$sys_path = '$ds'"
+	done
+
+	echo "zram set memory limit: OK"
+}
+
+zram_makeswap()
+{
+	echo "make swap with zram device(s)"
+	local i=$dev_start
+	for i in $(seq $dev_start $dev_end); do
+		mkswap /dev/zram$i > err.log 2>&1
+		if [ $? -ne 0 ]; then
+			cat err.log
+			echo "FAIL mkswap /dev/zram$1 failed"
+		fi
+
+		swapon /dev/zram$i > err.log 2>&1
+		if [ $? -ne 0 ]; then
+			cat err.log
+			echo "FAIL swapon /dev/zram$1 failed"
+		fi
+
+		echo "done with /dev/zram$i"
+		dev_makeswap=$i
+	done
+
+	echo "zram making zram mkswap and swapon: OK"
+}
+
+zram_swapoff()
+{
+	local i=
+	for i in $(seq $dev_start $dev_end); do
+		swapoff /dev/zram$i > err.log 2>&1
+		if [ $? -ne 0 ]; then
+			cat err.log
+			echo "FAIL swapoff /dev/zram$i failed"
+		fi
+	done
+	dev_makeswap=-1
+
+	echo "zram swapoff: OK"
+}
+
+zram_makefs()
+{
+	local i=$dev_start
+	for fs in $zram_filesystems; do
+		# if requested fs not supported default it to ext2
+		which mkfs.$fs > /dev/null 2>&1 || fs=ext2
+
+		echo "make $fs filesystem on /dev/zram$i"
+		mkfs.$fs /dev/zram$i > err.log 2>&1
+		if [ $? -ne 0 ]; then
+			cat err.log
+			echo "FAIL failed to make $fs on /dev/zram$i"
+		fi
+		i=$(($i + 1))
+		echo "zram mkfs.$fs: OK"
+	done
+}
+
+zram_mount()
+{
+	local i=0
+	for i in $(seq $dev_start $dev_end); do
+		echo "mount /dev/zram$i"
+		mkdir zram$i
+		mount /dev/zram$i zram$i > /dev/null || \
+			echo "FAIL mount /dev/zram$i failed"
+		dev_mounted=$i
+	done
+
+	echo "zram mount of zram device(s): OK"
+}