From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1F13E16F84E; Wed, 3 Jul 2024 11:03:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720004632; cv=none; b=OhdG6Ncb/YX0CgwWK4ZyfyL2l1OT65E0SxobD4/VvrvqwGgzAQeiG/8WnaWRibF9UGQebq7BdqaYLJiNa7HlfmUks+J/soeQtidkzP4fm7At6My9wpq4NUYG3trX61FdBTkq+rPKxooaWlix4oONMdOOS6MNqOKUujlDv4PL4h4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720004632; c=relaxed/simple; bh=rH9gVUj8+1oBU9kqShoXHJJXKhzHaHmKtUZG3yBVQRA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=KiD3p6orZmnmSLYyKWTewTfZKmIkPNPg0cwwgV+Pg6ySc1CXpuoGxJfjt08kSdG5PXLVwSrn3czxHuOHsnX2QNeM34KJTiti7Xn4gwmW+tdhGA06KmEGioFrldBLXqnvpqjDnO0IXJceg9PmXPoroOa96B9O3YU+lxgFphMqDK8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=W+8rgBBi; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="W+8rgBBi" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 97213C4AF0C; Wed, 3 Jul 2024 11:03:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1720004632; bh=rH9gVUj8+1oBU9kqShoXHJJXKhzHaHmKtUZG3yBVQRA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=W+8rgBBiq0KT5BM4/y75q9MRtzKSdwmoSgA2qKurK/Elq4jB22vFyrgQajW3exkNc buHO07Q/vQJjrdGQcHtpX05v+2XLzwN35NA44wQQsw79OWkdjyfZ/41knivqT5zUBq xXwob8erH/CUMlKs4wPYDwUeLZxjde4ZCLo6oynE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Linus Torvalds , "Paul E. McKenney" , "Uladzislau Rezki (Sony)" , Sasha Levin Subject: [PATCH 5.10 106/290] rcutorture: Fix rcu_torture_one_read() pipe_count overflow comment Date: Wed, 3 Jul 2024 12:38:07 +0200 Message-ID: <20240703102908.199928190@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240703102904.170852981@linuxfoundation.org> References: <20240703102904.170852981@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Paul E. McKenney [ Upstream commit 8b9b443fa860276822b25057cb3ff3b28734dec0 ] The "pipe_count > RCU_TORTURE_PIPE_LEN" check has a comment saying "Should not happen, but...". This is only true when testing an RCU whose grace periods are always long enough. This commit therefore fixes this comment. Reported-by: Linus Torvalds Closes: https://lore.kernel.org/lkml/CAHk-=wi7rJ-eGq+xaxVfzFEgbL9tdf6Kc8Z89rCpfcQOKm74Tw@mail.gmail.com/ Signed-off-by: Paul E. McKenney Signed-off-by: Uladzislau Rezki (Sony) Signed-off-by: Sasha Levin --- kernel/rcu/rcutorture.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index 6c1aea48a79a1..c413eb4a95667 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -1407,7 +1407,8 @@ static bool rcu_torture_one_read(struct torture_random_state *trsp) preempt_disable(); pipe_count = READ_ONCE(p->rtort_pipe_count); if (pipe_count > RCU_TORTURE_PIPE_LEN) { - /* Should not happen, but... */ + // Should not happen in a correct RCU implementation, + // happens quite often for torture_type=busted. pipe_count = RCU_TORTURE_PIPE_LEN; } completed = cur_ops->get_gp_seq(); -- 2.43.0