Commit e87c4f66 authored by Marco Elver's avatar Marco Elver Committed by Paul E. McKenney
Browse files

locking/atomics, kcsan: Add instrumentation for barriers 



Adds the required KCSAN instrumentation for barriers of atomics.

Signed-off-by: default avatarMarco Elver <elver@google.com>
Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
parent 2505a51a

include/linux/atomic/atomic-instrumented.h

+134 −1

File changed.

Preview size limit exceeded, changes collapsed.

scripts/atomic/gen-atomic-instrumented.sh

+32 −9
Original line number Diff line number Diff line
@@ -34,6 +34,14 @@ gen_param_check() 
gen_params_checks()

{

	local meta="$1"; shift

	local order="$1"; shift



	if [ "${order}" = "_release" ]; then

		printf "\tkcsan_release();\n"

	elif [ -z "${order}" ] && ! meta_in "$meta" "slv"; then

		# RMW with return value is fully ordered

		printf "\tkcsan_mb();\n"

	fi



	while [ "$#" -gt 0 ]; do

		gen_param_check "$meta" "$1"
@@ -56,7 +64,7 @@ gen_proto_order_variant() 


	local ret="$(gen_ret_type "${meta}" "${int}")"

	local params="$(gen_params "${int}" "${atomic}" "$@")"

	local checks="$(gen_params_checks "${meta}" "$@")"

	local checks="$(gen_params_checks "${meta}" "${order}" "$@")"

	local args="$(gen_args "$@")"

	local retstmt="$(gen_ret_stmt "${meta}")"
@@ -75,29 +83,44 @@ EOF 
gen_xchg()

{

	local xchg="$1"; shift

	local order="$1"; shift

	local mult="$1"; shift



	kcsan_barrier=""

	if [ "${xchg%_local}" = "${xchg}" ]; then

		case "$order" in

		_release)	kcsan_barrier="kcsan_release()" ;;

		"")			kcsan_barrier="kcsan_mb()" ;;

		esac

	fi



	if [ "${xchg%${xchg#try_cmpxchg}}" = "try_cmpxchg" ] ; then



cat <<EOF

#define ${xchg}(ptr, oldp, ...) \\

#define ${xchg}${order}(ptr, oldp, ...) \\

({ \\

	typeof(ptr) __ai_ptr = (ptr); \\

	typeof(oldp) __ai_oldp = (oldp); \\

EOF

[ -n "$kcsan_barrier" ] && printf "\t${kcsan_barrier}; \\\\\n"

cat <<EOF

	instrument_atomic_write(__ai_ptr, ${mult}sizeof(*__ai_ptr)); \\

	instrument_atomic_write(__ai_oldp, ${mult}sizeof(*__ai_oldp)); \\

	arch_${xchg}(__ai_ptr, __ai_oldp, __VA_ARGS__); \\

	arch_${xchg}${order}(__ai_ptr, __ai_oldp, __VA_ARGS__); \\

})

EOF



	else



cat <<EOF

#define ${xchg}(ptr, ...) \\

#define ${xchg}${order}(ptr, ...) \\

({ \\

	typeof(ptr) __ai_ptr = (ptr); \\

EOF

[ -n "$kcsan_barrier" ] && printf "\t${kcsan_barrier}; \\\\\n"

cat <<EOF

	instrument_atomic_write(__ai_ptr, ${mult}sizeof(*__ai_ptr)); \\

	arch_${xchg}(__ai_ptr, __VA_ARGS__); \\

	arch_${xchg}${order}(__ai_ptr, __VA_ARGS__); \\

})

EOF
@@ -145,21 +168,21 @@ done 


for xchg in "xchg" "cmpxchg" "cmpxchg64" "try_cmpxchg"; do

	for order in "" "_acquire" "_release" "_relaxed"; do

		gen_xchg "${xchg}${order}" ""

		gen_xchg "${xchg}" "${order}" ""

		printf "\n"

	done

done



for xchg in "cmpxchg_local" "cmpxchg64_local" "sync_cmpxchg"; do

	gen_xchg "${xchg}" ""

	gen_xchg "${xchg}" "" ""

	printf "\n"

done



gen_xchg "cmpxchg_double" "2 * "

gen_xchg "cmpxchg_double" "" "2 * "



printf "\n\n"



gen_xchg "cmpxchg_double_local" "2 * "

gen_xchg "cmpxchg_double_local" "" "2 * "



cat <<EOF