From:   Valentin Schneider <valentin.schneider@arm.com>
To:     linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com,
        linux-kbuild@vger.kernel.org
Cc:     Marco Elver <elver@google.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@kernel.org>,
        Frederic Weisbecker <frederic@kernel.org>,
        Mike Galbraith <efault@gmx.de>,
        Dmitry Vyukov <dvyukov@google.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Masahiro Yamada <masahiroy@kernel.org>,
        Michal Marek <michal.lkml@markovi.net>,
        Nick Desaulniers <ndesaulniers@google.com>
Subject: [PATCH v3 3/4] kcsan: Use preemption model accessors
Date:   Fri, 12 Nov 2021 18:52:02 +0000
Message-Id: <20211112185203.280040-4-valentin.schneider@arm.com>
In-Reply-To: <20211112185203.280040-1-valentin.schneider@arm.com>
References: <20211112185203.280040-1-valentin.schneider@arm.com>
MIME-Version: 1.0
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Per PREEMPT_DYNAMIC, checking CONFIG_PREEMPT doesn't tell you the actual
preemption model of the live kernel. Use the newly-introduced accessors
instead.

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Reviewed-by: Marco Elver <elver@google.com>
---
 kernel/kcsan/kcsan_test.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/kernel/kcsan/kcsan_test.c b/kernel/kcsan/kcsan_test.c
index dc55fd5a36fc..97cf1efce36a 100644
--- a/kernel/kcsan/kcsan_test.c
+++ b/kernel/kcsan/kcsan_test.c
@@ -1005,13 +1005,14 @@ static const void *nthreads_gen_params(const void *prev, char *desc)
 	else
 		nthreads *= 2;
 
-	if (!IS_ENABLED(CONFIG_PREEMPT) || !IS_ENABLED(CONFIG_KCSAN_INTERRUPT_WATCHER)) {
+	if (!preempt_model_preemptible() ||
+	    !IS_ENABLED(CONFIG_KCSAN_INTERRUPT_WATCHER)) {
 		/*
 		 * Without any preemption, keep 2 CPUs free for other tasks, one
 		 * of which is the main test case function checking for
 		 * completion or failure.
 		 */
-		const long min_unused_cpus = IS_ENABLED(CONFIG_PREEMPT_NONE) ? 2 : 0;
+		const long min_unused_cpus = preempt_model_none() ? 2 : 0;
 		const long min_required_cpus = 2 + min_unused_cpus;
 
 		if (num_online_cpus() < min_required_cpus) {
-- 
2.25.1