From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-14.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8472AC433DF for ; Mon, 24 Aug 2020 17:19:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 53E8B2067C for ; Mon, 24 Aug 2020 17:19:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598289565; bh=LnaqLY9ql4cWQoO1HlbbxQ5sT02Kl1si/mbPUnWBkbM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=JbpCbJ2lx3wS1jdKKE476qzNNljzXtHjFBWRcJyDYIyoMfADG4koHYTggWI12gn6N FFxg0IFDF0aR8+TtuX6UZyGre9qUR10B4YUp34A+LYj3sphNOZEax4T3j8/dCdSJKc f+HNJad2CVFKsWv0jDNw8OPjME/AOZSAqY3nc+cI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727053AbgHXRTV (ORCPT ); Mon, 24 Aug 2020 13:19:21 -0400 Received: from mail.kernel.org ([198.145.29.99]:40324 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728334AbgHXQgj (ORCPT ); Mon, 24 Aug 2020 12:36:39 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 0D03F22DA7; Mon, 24 Aug 2020 16:36:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598286981; bh=LnaqLY9ql4cWQoO1HlbbxQ5sT02Kl1si/mbPUnWBkbM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LnVzYf2q+/ZxhYqfm94Q9Zz7jIMrUt9aN2+gKLAPlZE1pQe6Ci7xFhM9AktjOyoNe dI/Fu6wkMSDSHZP6V9H1ssw4MRvkWcNbDTvnJGmMJTqrqPisPWyic44zs11LZ5bVe2 sw8Hznndyex6cEUOrBH52u7nu6o0dCzWJMv4PlCE= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Yonghong Song , Alexei Starovoitov , Rik van Riel , Sasha Levin , netdev@vger.kernel.org, bpf@vger.kernel.org Subject: [PATCH AUTOSEL 5.8 56/63] bpf: Avoid visit same object multiple times Date: Mon, 24 Aug 2020 12:34:56 -0400 Message-Id: <20200824163504.605538-56-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200824163504.605538-1-sashal@kernel.org> References: <20200824163504.605538-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Yonghong Song [ Upstream commit e60572b8d4c39572be6857d1ec91fdf979f8775f ] Currently when traversing all tasks, the next tid is always increased by one. This may result in visiting the same task multiple times in a pid namespace. This patch fixed the issue by seting the next tid as pid_nr_ns(pid, ns) + 1, similar to funciton next_tgid(). Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov Cc: Rik van Riel Link: https://lore.kernel.org/bpf/20200818222310.2181500-1-yhs@fb.com Signed-off-by: Sasha Levin --- kernel/bpf/task_iter.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/bpf/task_iter.c b/kernel/bpf/task_iter.c index ac7869a389990..cd7d9564bcef6 100644 --- a/kernel/bpf/task_iter.c +++ b/kernel/bpf/task_iter.c @@ -28,8 +28,9 @@ static struct task_struct *task_seq_get_next(struct pid_namespace *ns, rcu_read_lock(); retry: - pid = idr_get_next(&ns->idr, tid); + pid = find_ge_pid(*tid, ns); if (pid) { + *tid = pid_nr_ns(pid, ns); task = get_pid_task(pid, PIDTYPE_PID); if (!task) { ++*tid; -- 2.25.1