From 3570a1bcf45e9a7ddf9ba0e8d6d57cc67675cfef Mon Sep 17 00:00:00 2001
From: Marco Elver
Date: Fri, 24 Jul 2020 09:00:08 +0200
Subject: locking/atomics: Use read-write instrumentation for atomic RMWs

Use instrument_atomic_read_write() for atomic RMW ops.

Cc: Will Deacon <will@kernel.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: <linux-arch@vger.kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 scripts/atomic/gen-atomic-instrumented.sh | 21 +++++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)

(limited to 'scripts')

diff --git a/scripts/atomic/gen-atomic-instrumented.sh b/scripts/atomic/gen-atomic-instrumented.sh
index 6afadf73da17..2b7fec7e6abc 100755
--- a/scripts/atomic/gen-atomic-instrumented.sh
+++ b/scripts/atomic/gen-atomic-instrumented.sh
@@ -5,9 +5,10 @@ ATOMICDIR=$(dirname $0)
 
 . ${ATOMICDIR}/atomic-tbl.sh
 
-#gen_param_check(arg)
+#gen_param_check(meta, arg)
 gen_param_check()
 {
+	local meta="$1"; shift
 	local arg="$1"; shift
 	local type="${arg%%:*}"
 	local name="$(gen_param_name "${arg}")"
@@ -17,17 +18,25 @@ gen_param_check()
 	i) return;;
 	esac
 
-	# We don't write to constant parameters
-	[ ${type#c} != ${type} ] && rw="read"
+	if [ ${type#c} != ${type} ]; then
+		# We don't write to constant parameters.
+		rw="read"
+	elif [ "${meta}" != "s" ]; then
+		# An atomic RMW: if this parameter is not a constant, and this atomic is
+		# not just a 's'tore, this parameter is both read from and written to.
+		rw="read_write"
+	fi
 
 	printf "\tinstrument_atomic_${rw}(${name}, sizeof(*${name}));\n"
 }
 
-#gen_param_check(arg...)
+#gen_params_checks(meta, arg...)
 gen_params_checks()
 {
+	local meta="$1"; shift
+
 	while [ "$#" -gt 0 ]; do
-		gen_param_check "$1"
+		gen_param_check "$meta" "$1"
 		shift;
 	done
 }
@@ -77,7 +86,7 @@ gen_proto_order_variant()
 
 	local ret="$(gen_ret_type "${meta}" "${int}")"
 	local params="$(gen_params "${int}" "${atomic}" "$@")"
-	local checks="$(gen_params_checks "$@")"
+	local checks="$(gen_params_checks "${meta}" "$@")"
 	local args="$(gen_args "$@")"
 	local retstmt="$(gen_ret_stmt "${meta}")"
 
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