[PATCH 1/1] cpu: Add annotation inside clear_tasks_mm_cpumask()

From: Jules Irenge <jbi.octave@gmail.com>
To: linux-kernel@vger.kernel.org
Cc: boqun.feng@gmail.com, Thomas Gleixner <tglx@linutronix.de>,
	Jiri Kosina <jkosina@suse.cz>,
	Peter Zijlstra <peterz@infradead.org>,
	Josh Poimboeuf <jpoimboe@redhat.com>,
	Ingo Molnar <mingo@kernel.org>, Qian Cai <cai@lca.pw>,
	Eiichi Tsukata <devel@etsukata.com>,
	Pavankumar Kondeti <pkondeti@codeaurora.org>,
	Arnd Bergmann <arnd@arndb.de>,
	Tyler Hicks <tyhicks@canonical.com>
Subject: [PATCH 1/1] cpu: Add annotation inside clear_tasks_mm_cpumask()
Date: Wed, 15 Apr 2020 19:49:37 +0100	[thread overview]
Message-ID: <20200415184937.32373-2-jbi.octave@gmail.com> (raw)
In-Reply-To: <20200415184937.32373-1-jbi.octave@gmail.com>

Sparse reports a warning

warning: context imbalance in clear_tasks_mm_cpumask() - different lock contexts for basic block

The root cause is the missing annotation inside clear_tasks_mm_cpumask()

Add the missing __acquire(&t->alloc_lock) annotation.

Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
---
 kernel/cpu.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/cpu.c b/kernel/cpu.c
index 9c706af713fb..d8c452a8dd09 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -834,6 +834,7 @@ void clear_tasks_mm_cpumask(int cpu)
 		t = find_lock_task_mm(p);
 		if (!t)
 			continue;
+		__acquire(&t->alloc_lock);
 		cpumask_clear_cpu(cpu, mm_cpumask(t->mm));
 		task_unlock(t);
 	}
-- 
2.24.1

