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

1 files changed, 286 insertions, 0 deletions

diff --git a/scripts/coccicheck b/scripts/coccicheck
new file mode 100755
index 000000000..8dd766009
--- /dev/null
+++ b/scripts/coccicheck
@@ -0,0 +1,286 @@
+#!/usr/bin/env bash
+# SPDX-License-Identifier: GPL-2.0
+# Linux kernel coccicheck
+#
+# Read Documentation/dev-tools/coccinelle.rst
+#
+# This script requires at least spatch
+# version 1.0.0-rc11.
+
+DIR="$(dirname $(readlink -f $0))/.."
+SPATCH="`which ${SPATCH:=spatch}`"
+
+if [ ! -x "$SPATCH" ]; then
+    echo 'spatch is part of the Coccinelle project and is available at http://coccinelle.lip6.fr/'
+    exit 1
+fi
+
+SPATCH_VERSION=$($SPATCH --version | head -1 | awk '{print $3}')
+
+USE_JOBS="no"
+$SPATCH --help | grep -e "--jobs" > /dev/null && USE_JOBS="yes"
+
+# The verbosity may be set by the environmental parameter V=
+# as for example with 'make V=1 coccicheck'
+
+if [ -n "$V" -a "$V" != "0" ]; then
+	VERBOSE="$V"
+else
+	VERBOSE=0
+fi
+
+FLAGS="--very-quiet"
+
+# You can use SPFLAGS to append extra arguments to coccicheck or override any
+# heuristics done in this file as Coccinelle accepts the last options when
+# options conflict.
+#
+# A good example for use of SPFLAGS is if you want to debug your cocci script,
+# you can for instance use the following:
+#
+# $ export COCCI=scripts/coccinelle/misc/irqf_oneshot.cocci
+# $ make coccicheck MODE=report DEBUG_FILE="all.err" SPFLAGS="--profile --show-trying" M=./drivers/mfd/arizona-irq.c
+#
+# "--show-trying" should show you what rule is being processed as it goes to
+# stdout, you do not need a debug file for that. The profile output will be
+# be sent to stdout, if you provide a DEBUG_FILE the profiling data can be
+# inspected there.
+#
+# --profile will not output if --very-quiet is used, so avoid it.
+echo $SPFLAGS | grep -E -e "--profile|--show-trying" 2>&1 > /dev/null
+if [ $? -eq 0 ]; then
+	FLAGS="--quiet"
+fi
+
+# spatch only allows include directories with the syntax "-I include"
+# while gcc also allows "-Iinclude" and "-include include"
+COCCIINCLUDE=${LINUXINCLUDE//-I/-I }
+COCCIINCLUDE=${COCCIINCLUDE// -include/ --include}
+
+if [ "$C" = "1" -o "$C" = "2" ]; then
+    ONLINE=1
+
+    if [[ $# -le 0 ]]; then
+	    echo ''
+	    echo 'Specifying both the variable "C" and rule "coccicheck" in the make
+command results in a shift count error.'
+	    echo ''
+	    echo 'Try specifying "scripts/coccicheck" as a value for the CHECK variable instead.'
+	    echo ''
+	    echo 'Example:	make C=2 CHECK=scripts/coccicheck drivers/net/ethernet/ethoc.o'
+	    echo ''
+	    exit 1
+    fi
+
+    # Take only the last argument, which is the C file to test
+    shift $(( $# - 1 ))
+    OPTIONS="$COCCIINCLUDE $1"
+
+    # No need to parallelize Coccinelle since this mode takes one input file.
+    NPROC=1
+else
+    ONLINE=0
+    OPTIONS="--dir $srcroot $COCCIINCLUDE"
+
+    # Use only one thread per core by default if hyperthreading is enabled
+    THREADS_PER_CORE=$(LANG=C lscpu | grep "Thread(s) per core: " | tr -cd "[:digit:]")
+    if [ -z "$J" ]; then
+        NPROC=$(getconf _NPROCESSORS_ONLN)
+	if [ $THREADS_PER_CORE -gt 1 -a $NPROC -gt 4 ] ; then
+		NPROC=$((NPROC/2))
+	fi
+    else
+        NPROC="$J"
+    fi
+fi
+
+if [ "$KBUILD_EXTMOD" != "" ] ; then
+    OPTIONS="--patch $srctree $OPTIONS"
+fi
+
+# You can override by using SPFLAGS
+if [ "$USE_JOBS" = "no" ]; then
+	trap kill_running SIGTERM SIGINT
+	declare -a SPATCH_PID
+elif [ "$NPROC" != "1" ]; then
+	# Using 0 should work as well, refer to _SC_NPROCESSORS_ONLN use on
+	# https://github.com/rdicosmo/parmap/blob/master/setcore_stubs.c
+	OPTIONS="$OPTIONS --jobs $NPROC --chunksize 1"
+fi
+
+if [ "$MODE" = "" ] ; then
+    if [ "$ONLINE" = "0" ] ; then
+	echo 'You have not explicitly specified the mode to use. Using default "report" mode.'
+	echo 'Available modes are the following: patch, report, context, org, chain'
+	echo 'You can specify the mode with "make coccicheck MODE=<mode>"'
+	echo 'Note however that some modes are not implemented by some semantic patches.'
+    fi
+    MODE="report"
+fi
+
+if [ "$MODE" = "chain" ] ; then
+    if [ "$ONLINE" = "0" ] ; then
+	echo 'You have selected the "chain" mode.'
+	echo 'All available modes will be tried (in that order): patch, report, context, org'
+    fi
+elif [ "$MODE" = "report" -o "$MODE" = "org" ] ; then
+    FLAGS="--no-show-diff $FLAGS"
+fi
+
+if [ "$ONLINE" = "0" ] ; then
+    echo ''
+    echo 'Please check for false positives in the output before submitting a patch.'
+    echo 'When using "patch" mode, carefully review the patch before submitting it.'
+    echo ''
+fi
+
+run_cmd_parmap() {
+	if [ $VERBOSE -ne 0 ] ; then
+		echo "Running ($NPROC in parallel): $@"
+	fi
+	if [ "$DEBUG_FILE" != "/dev/null" ]; then
+                echo $@>>$DEBUG_FILE
+                $@ 2>>$DEBUG_FILE
+        else
+                echo $@
+                $@ 2>&1
+	fi
+
+	err=$?
+	if [[ $err -ne 0 ]]; then
+		echo "coccicheck failed"
+		exit $err
+	fi
+}
+
+run_cmd_old() {
+	local i
+	if [ $VERBOSE -ne 0 ] ; then
+		echo "Running ($NPROC in parallel): $@"
+	fi
+	for i in $(seq 0 $(( NPROC - 1)) ); do
+		eval "$@ --max $NPROC --index $i &"
+		SPATCH_PID[$i]=$!
+		if [ $VERBOSE -eq 2 ] ; then
+			echo "${SPATCH_PID[$i]} running"
+		fi
+	done
+	wait
+}
+
+run_cmd() {
+	if [ "$USE_JOBS" = "yes" ]; then
+		run_cmd_parmap $@
+	else
+		run_cmd_old $@
+	fi
+}
+
+kill_running() {
+	for i in $(seq 0 $(( NPROC - 1 )) ); do
+		if [ $VERBOSE -eq 2 ] ; then
+			echo "Killing ${SPATCH_PID[$i]}"
+		fi
+		kill ${SPATCH_PID[$i]} 2>/dev/null
+	done
+}
+
+# You can override heuristics with SPFLAGS, these must always go last
+OPTIONS="$OPTIONS $SPFLAGS"
+
+coccinelle () {
+    COCCI="$1"
+
+    OPT=`grep "Options:" $COCCI | cut -d':' -f2`
+    REQ=`grep "Requires:" $COCCI | cut -d':' -f2 | sed "s| ||"`
+    if [ -n "$REQ" ] && ! { echo "$REQ"; echo "$SPATCH_VERSION"; } | sort -CV ; then
+	    echo "Skipping coccinelle SmPL patch: $COCCI"
+	    echo "You have coccinelle:           $SPATCH_VERSION"
+	    echo "This SmPL patch requires:      $REQ"
+	    return
+    fi
+
+#   The option '--parse-cocci' can be used to syntactically check the SmPL files.
+#
+#    $SPATCH -D $MODE $FLAGS -parse_cocci $COCCI $OPT > /dev/null
+
+    if [ $VERBOSE -ne 0 -a $ONLINE -eq 0 ] ; then
+
+	FILE=${COCCI#$srctree/}
+
+	echo "Processing `basename $COCCI`"
+	echo "with option(s) \"$OPT\""
+	echo ''
+	echo 'Message example to submit a patch:'
+
+	sed -ne 's|^///||p' $COCCI
+
+	if [ "$MODE" = "patch" ] ; then
+	    echo ' The semantic patch that makes this change is available'
+	elif [ "$MODE" = "report" ] ; then
+	    echo ' The semantic patch that makes this report is available'
+	elif [ "$MODE" = "context" ] ; then
+	    echo ' The semantic patch that spots this code is available'
+	elif [ "$MODE" = "org" ] ; then
+	    echo ' The semantic patch that makes this Org report is available'
+	else
+	    echo ' The semantic patch that makes this output is available'
+	fi
+	echo " in $FILE."
+	echo ''
+	echo ' More information about semantic patching is available at'
+	echo ' http://coccinelle.lip6.fr/'
+	echo ''
+
+	if [ "`sed -ne 's|^//#||p' $COCCI`" ] ; then
+	    echo 'Semantic patch information:'
+	    sed -ne 's|^//#||p' $COCCI
+	    echo ''
+	fi
+    fi
+
+    if [ "$MODE" = "chain" ] ; then
+	run_cmd $SPATCH -D patch   \
+		$FLAGS --cocci-file $COCCI $OPT $OPTIONS               || \
+	run_cmd $SPATCH -D report  \
+		$FLAGS --cocci-file $COCCI $OPT $OPTIONS --no-show-diff || \
+	run_cmd $SPATCH -D context \
+		$FLAGS --cocci-file $COCCI $OPT $OPTIONS               || \
+	run_cmd $SPATCH -D org     \
+		$FLAGS --cocci-file $COCCI $OPT $OPTIONS --no-show-diff || exit 1
+    elif [ "$MODE" = "rep+ctxt" ] ; then
+	run_cmd $SPATCH -D report  \
+		$FLAGS --cocci-file $COCCI $OPT $OPTIONS --no-show-diff && \
+	run_cmd $SPATCH -D context \
+		$FLAGS --cocci-file $COCCI $OPT $OPTIONS || exit 1
+    else
+	run_cmd $SPATCH -D $MODE   $FLAGS --cocci-file $COCCI $OPT $OPTIONS || exit 1
+    fi
+
+}
+
+if [ "$DEBUG_FILE" = "" ]; then
+    echo 'You have not explicitly specified the debug file to use.'
+    echo 'Using default "/dev/null" as debug file.'
+    echo 'Debug logs will be printed to stdout.'
+    echo 'You can specify the debug file with "make coccicheck DEBUG_FILE=<debug_file>"'
+    echo ''
+    DEBUG_FILE="/dev/null"
+fi
+
+if [ -f $DEBUG_FILE ]; then
+	echo "Debug file $DEBUG_FILE exists, bailing"
+	exit
+fi
+
+if [ "$COCCI" = "" ] ; then
+    for f in `find $srctree/scripts/coccinelle/ -name '*.cocci' -type f | sort`; do
+        if grep -q "virtual[[:space:]]\+$MODE" "$f"; then
+                coccinelle $f
+        else
+                echo "warning: Skipping $f as it does not match mode '$MODE'"
+        fi
+    done
+else
+    coccinelle $COCCI
+fi