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, 332 insertions, 0 deletions

diff --git a/scripts/patch-kernel b/scripts/patch-kernel
new file mode 100755
index 000000000..033d59167
--- /dev/null
+++ b/scripts/patch-kernel
@@ -0,0 +1,332 @@
+#! /bin/sh
+# SPDX-License-Identifier: GPL-2.0
+# Script to apply kernel patches.
+#   usage: patch-kernel [ sourcedir [ patchdir [ stopversion ] [ -acxx ] ] ]
+#     The source directory defaults to /usr/src/linux, and the patch
+#     directory defaults to the current directory.
+# e.g.
+#   scripts/patch-kernel . ..
+#      Update the kernel tree in the current directory using patches in the
+#      directory above to the latest Linus kernel
+#   scripts/patch-kernel . .. -ac
+#      Get the latest Linux kernel and patch it with the latest ac patch
+#   scripts/patch-kernel . .. 2.4.9
+#      Gets standard kernel 2.4.9
+#   scripts/patch-kernel . .. 2.4.9 -ac
+#      Gets 2.4.9 with latest ac patches
+#   scripts/patch-kernel . .. 2.4.9 -ac11
+#      Gets 2.4.9 with ac patch ac11
+#   Note: It uses the patches relative to the Linus kernels, not the
+#   ac to ac relative patches
+#
+# It determines the current kernel version from the top-level Makefile.
+# It then looks for patches for the next sublevel in the patch directory.
+# This is applied using "patch -p1 -s" from within the kernel directory.
+# A check is then made for "*.rej" files to see if the patch was
+# successful.  If it is, then all of the "*.orig" files are removed.
+#
+#       Nick Holloway <Nick.Holloway@alfie.demon.co.uk>, 2nd January 1995.
+#
+# Added support for handling multiple types of compression. What includes
+# gzip, bzip, bzip2, zip, compress, and plaintext.
+#
+#       Adam Sulmicki <adam@cfar.umd.edu>, 1st January 1997.
+#
+# Added ability to stop at a given version number
+# Put the full version number (i.e. 2.3.31) as the last parameter
+#       Dave Gilbert <linux@treblig.org>, 11th December 1999.
+
+# Fixed previous patch so that if we are already at the correct version
+# not to patch up.
+#
+# Added -ac option, use -ac or -ac9 (say) to stop at a particular version
+#       Dave Gilbert <linux@treblig.org>, 29th September 2001.
+#
+# Add support for (use of) EXTRAVERSION (to support 2.6.8.x, e.g.);
+# update usage message;
+# fix some whitespace damage;
+# be smarter about stopping when current version is larger than requested;
+#	Randy Dunlap <rdunlap@xenotime.net>, 2004-AUG-18.
+#
+# Add better support for (non-incremental) 2.6.x.y patches;
+# If an ending version number if not specified, the script automatically
+# increments the SUBLEVEL (x in 2.6.x.y) until no more patch files are found;
+# however, EXTRAVERSION (y in 2.6.x.y) is never automatically incremented
+# but must be specified fully.
+#
+# patch-kernel does not normally support reverse patching, but does so when
+# applying EXTRAVERSION (x.y) patches, so that moving from 2.6.11.y to 2.6.11.z
+# is easy and handled by the script (reverse 2.6.11.y and apply 2.6.11.z).
+#	Randy Dunlap <rdunlap@xenotime.net>, 2005-APR-08.
+
+PNAME=patch-kernel
+
+# Set directories from arguments, or use defaults.
+sourcedir=${1-/usr/src/linux}
+patchdir=${2-.}
+stopvers=${3-default}
+
+if [ "$1" = -h -o "$1" = --help -o ! -r "$sourcedir/Makefile" ]; then
+cat << USAGE
+usage: $PNAME [-h] [ sourcedir [ patchdir [ stopversion ] [ -acxx ] ] ]
+  source directory defaults to /usr/src/linux,
+  patch directory defaults to the current directory,
+  stopversion defaults to <all in patchdir>.
+USAGE
+exit 1
+fi
+
+# See if we have any -ac options
+for PARM in $*
+do
+  case $PARM in
+	  -ac*)
+		  gotac=$PARM;
+
+	esac;
+done
+
+# ---------------------------------------------------------------------------
+# arg1 is filename
+noFile () {
+	echo "cannot find patch file: ${patch}"
+	exit 1
+}
+
+# ---------------------------------------------------------------------------
+backwards () {
+	echo "$PNAME does not support reverse patching"
+	exit 1
+}
+
+# ---------------------------------------------------------------------------
+# Find a file, first parameter is basename of file
+# it tries many compression mechanisms and sets variables to say how to get it
+findFile () {
+  filebase=$1;
+
+  if [ -r ${filebase}.gz ]; then
+		ext=".gz"
+		name="gzip"
+		uncomp="gunzip -dc"
+  elif [ -r ${filebase}.bz  ]; then
+		ext=".bz"
+		name="bzip"
+		uncomp="bunzip -dc"
+  elif [ -r ${filebase}.bz2 ]; then
+		ext=".bz2"
+		name="bzip2"
+		uncomp="bunzip2 -dc"
+  elif [ -r ${filebase}.xz ]; then
+                ext=".xz"
+                name="xz"
+                uncomp="xz -dc"
+  elif [ -r ${filebase}.zip ]; then
+		ext=".zip"
+		name="zip"
+		uncomp="unzip -d"
+  elif [ -r ${filebase}.Z ]; then
+		ext=".Z"
+		name="uncompress"
+		uncomp="uncompress -c"
+  elif [ -r ${filebase} ]; then
+		ext=""
+		name="plaintext"
+		uncomp="cat"
+  else
+	return 1;
+  fi
+
+  return 0;
+}
+
+# ---------------------------------------------------------------------------
+# Apply a patch and check it goes in cleanly
+# First param is patch name (e.g. patch-2.4.9-ac5) - without path or extension
+
+applyPatch () {
+  echo -n "Applying $1 (${name})... "
+  if $uncomp ${patchdir}/$1${ext} | patch -p1 -s -N -E -d $sourcedir
+  then
+    echo "done."
+  else
+    echo "failed.  Clean up yourself."
+    return 1;
+  fi
+  if [ "`find $sourcedir/ '(' -name '*.rej' -o -name '.*.rej' ')' -print`" ]
+  then
+    echo "Aborting.  Reject files found."
+    return 1;
+  fi
+  # Remove backup files
+  find $sourcedir/ '(' -name '*.orig' -o -name '.*.orig' ')' -exec rm -f {} \;
+
+  return 0;
+}
+
+# ---------------------------------------------------------------------------
+# arg1 is patch filename
+reversePatch () {
+	echo -n "Reversing $1 (${name}) ... "
+	if $uncomp ${patchdir}/"$1"${ext} | patch -p1 -Rs -N -E -d $sourcedir
+	then
+		echo "done."
+	else
+		echo "failed.  Clean it up."
+		exit 1
+	fi
+	if [ "`find $sourcedir/ '(' -name '*.rej' -o -name '.*.rej' ')' -print`" ]
+	then
+		echo "Aborting.  Reject files found."
+		return 1
+	fi
+	# Remove backup files
+	find $sourcedir/ '(' -name '*.orig' -o -name '.*.orig' ')' -exec rm -f {} \;
+
+	return 0
+}
+
+# set current VERSION, PATCHLEVEL, SUBLEVEL, EXTRAVERSION
+# force $TMPFILEs below to be in local directory: a slash character prevents
+# the dot command from using the search path.
+TMPFILE=`mktemp ./.tmpver.XXXXXX` || { echo "cannot make temp file" ; exit 1; }
+grep -E "^(VERSION|PATCHLEVEL|SUBLEVEL|EXTRAVERSION)" $sourcedir/Makefile > $TMPFILE
+tr -d [:blank:] < $TMPFILE > $TMPFILE.1
+. $TMPFILE.1
+rm -f $TMPFILE*
+if [ -z "$VERSION" -o -z "$PATCHLEVEL" -o -z "$SUBLEVEL" ]
+then
+    echo "unable to determine current kernel version" >&2
+    exit 1
+fi
+
+NAME=`grep ^NAME $sourcedir/Makefile`
+NAME=${NAME##*=}
+
+echo "Current kernel version is $VERSION.$PATCHLEVEL.$SUBLEVEL${EXTRAVERSION} ($NAME)"
+
+# strip EXTRAVERSION to just a number (drop leading '.' and trailing additions)
+EXTRAVER=
+if [ x$EXTRAVERSION != "x" ]
+then
+	EXTRAVER=${EXTRAVERSION#.}
+	EXTRAVER=${EXTRAVER%%[[:punct:]]*}
+	#echo "$PNAME: changing EXTRAVERSION from $EXTRAVERSION to $EXTRAVER"
+fi
+
+#echo "stopvers=$stopvers"
+if [ $stopvers != "default" ]; then
+	STOPSUBLEVEL=`echo $stopvers | cut -d. -f3`
+	STOPEXTRA=`echo $stopvers | cut -d. -f4`
+	STOPFULLVERSION=${stopvers%%.$STOPEXTRA}
+	#echo "#___STOPSUBLEVEL=/$STOPSUBLEVEL/, STOPEXTRA=/$STOPEXTRA/"
+else
+	STOPSUBLEVEL=9999
+	STOPEXTRA=9999
+fi
+
+# This all assumes a 2.6.x[.y] kernel tree.
+# Don't allow backwards/reverse patching.
+if [ $STOPSUBLEVEL -lt $SUBLEVEL ]; then
+	backwards
+fi
+
+if [ x$EXTRAVER != "x" ]; then
+	CURRENTFULLVERSION="$VERSION.$PATCHLEVEL.$SUBLEVEL.$EXTRAVER"
+else
+	CURRENTFULLVERSION="$VERSION.$PATCHLEVEL.$SUBLEVEL"
+fi
+
+if [ x$EXTRAVER != "x" ]; then
+	echo "backing up to: $VERSION.$PATCHLEVEL.$SUBLEVEL"
+	patch="patch-${CURRENTFULLVERSION}"
+	findFile $patchdir/${patch} || noFile ${patch}
+	reversePatch ${patch} || exit 1
+fi
+
+# now current is 2.6.x, with no EXTRA applied,
+# so update to target SUBLEVEL (2.6.SUBLEVEL)
+# and then to target EXTRAVER (2.6.SUB.EXTRAVER) if requested.
+# If not ending sublevel is specified, it is incremented until
+# no further sublevels are found.
+
+if [ $STOPSUBLEVEL -gt $SUBLEVEL ]; then
+while :				# incrementing SUBLEVEL (s in v.p.s)
+do
+    CURRENTFULLVERSION="$VERSION.$PATCHLEVEL.$SUBLEVEL"
+    EXTRAVER=
+    if [ x$STOPFULLVERSION = x$CURRENTFULLVERSION ]; then
+        echo "Stopping at $CURRENTFULLVERSION base as requested."
+        break
+    fi
+
+    SUBLEVEL=$(($SUBLEVEL + 1))
+    FULLVERSION="$VERSION.$PATCHLEVEL.$SUBLEVEL"
+    #echo "#___ trying $FULLVERSION ___"
+
+    if [ $(($SUBLEVEL)) -gt $(($STOPSUBLEVEL)) ]; then
+	echo "Stopping since sublevel ($SUBLEVEL) is beyond stop-sublevel ($STOPSUBLEVEL)"
+	exit 1
+    fi
+
+    patch=patch-$FULLVERSION
+    # See if the file exists and find extension
+    findFile $patchdir/${patch} || noFile ${patch}
+
+    # Apply the patch and check all is OK
+    applyPatch $patch || break
+done
+#echo "#___sublevel all done"
+fi
+
+# There is no incremental searching for extraversion...
+if [ "$STOPEXTRA" != "" ]; then
+while :				# just to allow break
+do
+# apply STOPEXTRA directly (not incrementally) (x in v.p.s.x)
+	FULLVERSION="$VERSION.$PATCHLEVEL.$SUBLEVEL.$STOPEXTRA"
+	#echo "#... trying $FULLVERSION ..."
+	patch=patch-$FULLVERSION
+
+	# See if the file exists and find extension
+	findFile $patchdir/${patch} || noFile ${patch}
+
+	# Apply the patch and check all is OK
+	applyPatch $patch || break
+	#echo "#___extraver all done"
+	break
+done
+fi
+
+if [ x$gotac != x ]; then
+  # Out great user wants the -ac patches
+	# They could have done -ac (get latest) or -acxx where xx=version they want
+	if [ $gotac = "-ac" ]; then
+	  # They want the latest version
+		HIGHESTPATCH=0
+		for PATCHNAMES in $patchdir/patch-${CURRENTFULLVERSION}-ac*\.*
+		do
+			ACVALUE=`echo $PATCHNAMES | sed -e 's/^.*patch-[0-9.]*-ac\([0-9]*\).*/\1/'`
+			# Check it is actually a recognised patch type
+			findFile $patchdir/patch-${CURRENTFULLVERSION}-ac${ACVALUE} || break
+
+		  if [ $ACVALUE -gt $HIGHESTPATCH ]; then
+			  HIGHESTPATCH=$ACVALUE
+		  fi
+		done
+
+		if [ $HIGHESTPATCH -ne 0 ]; then
+			findFile $patchdir/patch-${CURRENTFULLVERSION}-ac${HIGHESTPATCH} || break
+			applyPatch patch-${CURRENTFULLVERSION}-ac${HIGHESTPATCH}
+		else
+		  echo "No -ac patches found"
+		fi
+	else
+	  # They want an exact version
+		findFile $patchdir/patch-${CURRENTFULLVERSION}${gotac} || {
+		  echo "Sorry, I couldn't find the $gotac patch for $CURRENTFULLVERSION.  Hohum."
+			exit 1
+		}
+		applyPatch patch-${CURRENTFULLVERSION}${gotac}
+	fi
+fi