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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 820CBECE58C for ; Wed, 9 Oct 2019 16:09:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5F773218DE for ; Wed, 9 Oct 2019 16:09:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731809AbfJIQJk (ORCPT ); Wed, 9 Oct 2019 12:09:40 -0400 Received: from mx1.redhat.com ([209.132.183.28]:40160 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731686AbfJIQJj (ORCPT ); Wed, 9 Oct 2019 12:09:39 -0400 Received: from mail-ed1-f69.google.com (mail-ed1-f69.google.com [209.85.208.69]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id F021A8763B for ; Wed, 9 Oct 2019 16:09:38 +0000 (UTC) Received: by mail-ed1-f69.google.com with SMTP id y21so1705218edr.18 for ; Wed, 09 Oct 2019 09:09:38 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=yo8HgxFaUzFJT5aifHeLW47+7+qi0Gxu8+x3gkt5AcY=; b=b0Ze0wauzkoEHT/peMYcxSr3hrH8ToGF+9H0lTpL77SVs6Cf5I1LcFFNYVsrxJdRte aWaMjpmn3LeMxPxelT/ah53Y5LGO/Z0lNROh3dCCTzk27+4lIspIKGXFtBf5MVkM0QSt liIPqbA0afG7tc3oxZpIkXw0aWqxpVpZ8I1QETE3s+VHNL5e/Baz+f92G5QsyxAqtnU8 wZX84WmHd1oK4wNMTE1WClXBPvhkQc+9VEZ8O7gqpY87tzGzQJfjm63iqckT18NTLX6Z ehzZn2ir7qW6vJnCSmyJpqu2ku0KgQaro78F431hmN69A7QK/tqBDA2o8RL5ECYLLEPG pECg== X-Gm-Message-State: APjAAAWUlwGEZQTnTehSNr50W1RaDucH8lmjm8fkJvf7Klkx3NiC5Jju 3HEVi7bhb/PuQAWo6xkStdbescce6sD2sRaBwXli1XbM/qRvKmPHgSAHv+alrE+RjBw/z36V1HC yvcsmuE8Y8Mu2nCtzK3Iy8Agv X-Received: by 2002:a17:906:8598:: with SMTP id v24mr3576960ejx.328.1570637377270; Wed, 09 Oct 2019 09:09:37 -0700 (PDT) X-Google-Smtp-Source: APXvYqzIa1NlC5x/Y/DxrahdimMpGxXuvwAyvm2TeQKg29VSeDf6iUFdplanwS4MmX2Wk7mlZDp32A== X-Received: by 2002:a17:906:8598:: with SMTP id v24mr3576934ejx.328.1570637377052; Wed, 09 Oct 2019 09:09:37 -0700 (PDT) Received: from localhost ([2a02:2450:102e:d85:877d:43b4:dd8f:144d]) by smtp.gmail.com with ESMTPSA id e52sm415148eda.36.2019.10.09.09.09.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 09 Oct 2019 09:09:36 -0700 (PDT) From: Christian Kellner To: linux-kernel@vger.kernel.org Cc: linux-api@vger.kernel.org, Christian Kellner , Christian Brauner , Andrew Morton , "Peter Zijlstra (Intel)" , Ingo Molnar , Michal Hocko , Elena Reshetova , Thomas Gleixner , Roman Gushchin , Andrea Arcangeli , "Joel Fernandes (Google)" , Al Viro , "Dmitry V. Levin" Subject: [PATCH v2 1/2] pidfd: show pids for nested pid namespaces in fdinfo Date: Wed, 9 Oct 2019 18:05:30 +0200 Message-Id: <20191009160532.20674-1-ckellner@redhat.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20191008133641.23019-1-ckellner@redhat.com> References: <20191008133641.23019-1-ckellner@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Christian Kellner The fdinfo file for a process file descriptor already contains the pid of the process in the callers namespaces. Additionally, if pid namespaces are configured, show the process ids of the process in all nested namespaces in the same format as in the procfs status file, i.e. "NSPid:\t%d\%d...". This allows the easy identification of the processes in nested namespaces. Signed-off-by: Christian Kellner --- Changes in v2: - Moved into separate function to avoid multiple ifdefs as suggested by Michal Hocko kernel/fork.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/kernel/fork.c b/kernel/fork.c index 5a0fd518e04e..f7a59ef046e9 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1681,12 +1681,27 @@ static int pidfd_release(struct inode *inode, struct file *file) } #ifdef CONFIG_PROC_FS +static void pidfd_nspid(struct seq_file *m, struct pid *pid) +{ +#ifdef CONFIG_PID_NS + struct pid_namespace *ns = proc_pid_ns(file_inode(m->file)); + int i; + + seq_puts(m, "\nNSpid:"); + for (i = ns->level; i <= pid->level; i++) { + ns = pid->numbers[i].ns; + seq_put_decimal_ull(m, "\t", pid_nr_ns(pid, ns)); + } +#endif +} + static void pidfd_show_fdinfo(struct seq_file *m, struct file *f) { struct pid_namespace *ns = proc_pid_ns(file_inode(m->file)); struct pid *pid = f->private_data; seq_put_decimal_ull(m, "Pid:\t", pid_nr_ns(pid, ns)); + pidfd_nspid(m, pid); seq_putc(m, '\n'); } #endif -- 2.21.0