[PATCH] exit.c: Fix Sparse errors and warnings

From: madhuparnabhowmik10@gmail.com
To: peterz@infradead.org, mingo@kernel.org, oleg@redhat.com,
	christian.brauner@ubuntu.com, paulmck@kernel.org
Cc: linux-kernel@vger.kernel.org, joel@joelfernandes.org,
	linux-kernel-mentees@lists.linuxfoundation.org,
	rcu@vger.kernel.org,
	Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
Subject: [PATCH] exit.c: Fix Sparse errors and warnings
Date: Tue, 28 Jan 2020 22:50:08 +0530	[thread overview]
Message-ID: <20200128172008.22665-1-madhuparnabhowmik10@gmail.com> (raw)

From: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>

This patch fixes the following sparse error:
kernel/exit.c:627:25: error: incompatible types in comparison expression
caused due to accessing rcu protected pointer without using rcu primitives.

And the following warning:

kernel/exit.c:626:40: warning: incorrect type in assignment

Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
---
 kernel/exit.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/exit.c b/kernel/exit.c
index bcbd59888e67..c5a9d6360440 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -623,8 +623,8 @@ static void forget_original_parent(struct task_struct *father,
 	reaper = find_new_reaper(father, reaper);
 	list_for_each_entry(p, &father->children, sibling) {
 		for_each_thread(p, t) {
-			t->real_parent = reaper;
-			BUG_ON((!t->ptrace) != (t->parent == father));
+			rcu_assign_pointer(t->real_parent, reaper);
+			BUG_ON((!t->ptrace) != (rcu_access_pointer(t->parent) == father));
 			if (likely(!t->ptrace))
 				t->parent = t->real_parent;
 			if (t->pdeath_signal)
-- 
2.17.1

