Revision be0f272bfc83797f70d44faca86954df62e2bbc0 authored by Ard Biesheuvel on 20 November 2017, 17:41:30 UTC, committed by Will Deacon on 01 December 2017, 13:04:59 UTC
When building the arm64 kernel with both CONFIG_ARM64_MODULE_PLTS and
CONFIG_DYNAMIC_FTRACE enabled, the ftrace-mod.o object file is built
with the kernel and contains a trampoline that is linked into each
module, so that modules can be loaded far away from the kernel and
still reach the ftrace entry point in the core kernel with an ordinary
relative branch, as is emitted by the compiler instrumentation code
dynamic ftrace relies on.

In order to be able to build out of tree modules, this object file
needs to be included into the linux-headers or linux-devel packages,
which is undesirable, as it makes arm64 a special case (although a
precedent does exist for 32-bit PPC).

Given that the trampoline essentially consists of a PLT entry, let's
not bother with a source or object file for it, and simply patch it
in whenever the trampoline is being populated, using the existing
PLT support routines.

Cc: <stable@vger.kernel.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
1 parent 7e8b9c1
Raw File
coccicheck
#!/bin/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 $3}')
SPATCH_VERSION_NUM=$(echo $SPATCH_VERSION | ${DIR}/scripts/ld-version.sh)

USE_JOBS="no"
$SPATCH --help | grep "\-\-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 | egrep -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

    # 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
    if [ "$KBUILD_EXTMOD" = "" ] ; then
        OPTIONS="--dir $srctree $COCCIINCLUDE"
    else
        OPTIONS="--dir $KBUILD_EXTMOD $COCCIINCLUDE"
    fi

    if [ -z "$J" ]; then
        NPROC=$(getconf _NPROCESSORS_ONLN)
    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'
	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
	echo $@ >>$DEBUG_FILE
	$@ 2>>$DEBUG_FILE
	if [[ $? -ne 0 ]]; then
		echo "coccicheck failed"
		exit $?
	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:" $COCCI | cut -d':' -f2 | sed "s| ||"`
    REQ_NUM=$(echo $REQ | ${DIR}/scripts/ld-version.sh)
    if [ "$REQ_NUM" != "0" ] ; then
	    if [ "$SPATCH_VERSION_NUM" -lt "$REQ_NUM" ] ; then
		    echo "Skipping coccinele SmPL patch: $COCCI"
		    echo "You have coccinelle:           $SPATCH_VERSION"
		    echo "This SmPL patch requires:      $REQ"
		    return
	    fi
    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 [ "$DEBUG_FILE" != "/dev/null" -a "$DEBUG_FILE" != "" ]; then
	if [ -f $DEBUG_FILE ]; then
		echo "Debug file $DEBUG_FILE exists, bailing"
		exit
	fi
else
	DEBUG_FILE="/dev/null"
fi

if [ "$COCCI" = "" ] ; then
    for f in `find $srctree/scripts/coccinelle/ -name '*.cocci' -type f | sort`; do
	coccinelle $f
    done
else
    coccinelle $COCCI
fi
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