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[89.10.169.238]) by smtp.gmail.com with ESMTPSA id v7sm1134696ljk.60.2021.01.16.09.37.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 16 Jan 2021 09:37:53 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=uged.al; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=mxEgYGcQCZYKbRq3K2ngs08xWDWh3dTlzcMk23rneeQ=; b=ONxNoEUrPCGxB6M5IFJ2CYG1sWXTpgzhj4aK4aqkMTe61PAhVJloH06apvC5JWcFYn qQFHhWWe9VTPKnx28O/ZleRGHikVSkzCP+e4+/cYbbLnf/wy3ZZgp0f3ph6YvtxIEksu yYmJZTMSpIKT7RagJYoXr1jQ7gMgsYDnSC871szh7d8+3WYjo63Y7PSk4/NsSd3eau2C 7vGY5Y2VE/0E5rXhD9Mcklt2BcvPfgwNJR3jHrYwrfaS55ry0tWwzLm9/laqA1xawliJ E/XKgcnyO1OB4Nd0xu35HGQdMLTIj7k+176Ne6oy4IrSwgqxuTFyow9EZvABxykXEP16 uS4A== 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=mxEgYGcQCZYKbRq3K2ngs08xWDWh3dTlzcMk23rneeQ=; b=ptcg9MA0YW82bPw4dnTw0beM+en51g8p97rSdnbxipxPlkUmMeRiPW2eb9S5SmeOll WFFcU1qjY1UKmIzz2Mk1DhQcgQQ+b0ziDEusFXRKsdXrA8X0yIdW+lbdP8dFXFVlidyp kVWimO7Qt+KYwfp7+qYaIYId8m4I7rPLVNq/UWDbzmVaGFLqqU1KcC5EIcQBjIyy0y8j L+CNvyo98r16zriqURjZMD8i2SJHDuWwCVIyCbFtOVPZQnlBJ1mBHziolPLdFpmWAeeU eQoqlhi/yFXtMUBsPBSQgA2vrb7IXV6sOTGii0uqRdtcbLp/Ev1pW9bKr3M/+I7Tk1a/ uLHg== X-Gm-Message-State: AOAM531yYSmg5GN1YCwbmPioKTz8bahBtTMzumg3j93Es4XZ3KrGyn3W hNzq8bnUjvK8WYlA5cGVd5cl1g== X-Google-Smtp-Source: ABdhPJzZ2isHzSByM6U4LO4hvKLBiheZz/goKXIzhuOgnnX0KV/FV43e81LoAdS2DlMtgwtKZsxjLg== X-Received: by 2002:ac2:4431:: with SMTP id w17mr7598763lfl.223.1610818673989; Sat, 16 Jan 2021 09:37:53 -0800 (PST) From: Odin Ugedal Cc: tj@kernel.org, lizefan@huawei.com, hannes@cmpxchg.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, dschatzberg@fb.com, surenb@google.com, Odin Ugedal Subject: [PATCH v2 1/2] cgroup: fix psi monitor for root cgroup Date: Sat, 16 Jan 2021 18:36:33 +0100 Message-Id: <20210116173634.1615875-2-odin@uged.al> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210116173634.1615875-1-odin@uged.al> References: <20210116173634.1615875-1-odin@uged.al> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable To: unlisted-recipients:; (no To-header on input) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-ZohoMail-DKIM: fail (Header signature does not verify) Content-Type: text/plain; charset="utf-8" Fix NULL pointer dereference when adding new psi monitor to the root cgroup. PSI files for root cgroup was introduced in df5ba5be742 by using system wide psi struct when reading, but file write/monitor was not properly fixed. Since the PSI config for the root cgroup isn't initialized, the current implementation tries to lock a NULL ptr, resulting in a crash. Can be triggered by running this as root: $ tee /sys/fs/cgroup/cpu.pressure <<< "some 10000 1000000" Signed-off-by: Odin Ugedal Reviewed-by: Suren Baghdasaryan --- kernel/cgroup/cgroup.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 613845769103..1ea995f801ec 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -3564,6 +3564,7 @@ static ssize_t cgroup_pressure_write(struct kernfs_op= en_file *of, char *buf, { struct psi_trigger *new; struct cgroup *cgrp; + struct psi_group *psi; =20 cgrp =3D cgroup_kn_lock_live(of->kn, false); if (!cgrp) @@ -3572,7 +3573,8 @@ static ssize_t cgroup_pressure_write(struct kernfs_op= en_file *of, char *buf, cgroup_get(cgrp); cgroup_kn_unlock(of->kn); =20 - new =3D psi_trigger_create(&cgrp->psi, buf, nbytes, res); + psi =3D cgroup_ino(cgrp) =3D=3D 1 ? &psi_system : &cgrp->psi; + new =3D psi_trigger_create(psi, buf, nbytes, res); if (IS_ERR(new)) { cgroup_put(cgrp); return PTR_ERR(new); --=20 2.30.0 From nobody Sat May 10 00:06:17 2025 Delivered-To: importer2@patchew.org Received-SPF: pass (zohomail.com: domain of vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; envelope-from=linux-kernel-owner@vger.kernel.org; helo=vger.kernel.org; Authentication-Results: mx.zohomail.com; dkim=fail; spf=pass (zohomail.com: domain of vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; t=1610818784; cv=none; d=zohomail.com; s=zohoarc; b=UFdIALCXzYtuaweHd5ad6BZUwGekwf0092TNXJcaW8nP1C+shNpChFEYYWJmHXf0h4iOiPCOULCYqPOe663/dp9Sx1teJsJQL6cbcFzYHLRJLynFSTM3JerN60dHtmtFDr9eIlcgU1Q3wz/rLZc+713Ml+NxlqaP0TdIl9DY+Jo= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1610818784; h=Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Id:MIME-Version:Message-ID:References:Subject:To; bh=RXhQCLR7kJ8wXIoAGktxHEJsN7Fs/rfacZeAYDKFmIs=; b=OtkET1IFuF/jXHsFjzI8+YsKZcA+U+uH/hI6qXtHkllAgj6p5gT6DEWxUmblwtjkhYEsQVKsCF8OBa2TUOc4DLeAjzPeqc10D1pa+r7gcf/IVN43b/yR7zzq9RSD38WpmXUrfTQacaSYRodcDqG17i6KPKHSIOjH73iu/g5keXE= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=fail; spf=pass (zohomail.com: domain of vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mx.zohomail.com with SMTP id 1610818784584587.6567324973355; Sat, 16 Jan 2021 09:39:44 -0800 (PST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727649AbhAPRjH (ORCPT ); Sat, 16 Jan 2021 12:39:07 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45308 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727495AbhAPRjG (ORCPT ); Sat, 16 Jan 2021 12:39:06 -0500 Received: from mail-lf1-x12e.google.com (mail-lf1-x12e.google.com [IPv6:2a00:1450:4864:20::12e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 50C4DC061574 for ; Sat, 16 Jan 2021 09:38:26 -0800 (PST) Received: by mail-lf1-x12e.google.com with SMTP id x20so17917883lfe.12 for ; Sat, 16 Jan 2021 09:38:26 -0800 (PST) Received: from xps.lan (238.89-10-169.nextgentel.com. [89.10.169.238]) by smtp.gmail.com with ESMTPSA id v7sm1134696ljk.60.2021.01.16.09.38.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 16 Jan 2021 09:38:24 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=uged.al; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=RXhQCLR7kJ8wXIoAGktxHEJsN7Fs/rfacZeAYDKFmIs=; b=sdBAnkXLZiSEhGYam1qUuWzP56Niue66DVFgEdt1Rz43y1S6IdNFkfCnwls9cXBoRu H7Mnh4NEeCcFDxV/x+NRCPo572ISiOPh2+Ui0cn3wJesaGBeK2/nAQPu7QM/UfEsE1ps 9fcwB7f1eBXAxTylN12jvL0Ey7MioXV1IipxMvuY78uF7QVVq68JWJ/eBgv2qjDpGueo k2Gej1o/CGHMjBTgKXsb/V0+efCE+YjLhpZvBazc6WFgZGVl/X8yPhswVTWPdp7BS3Ts 358Nhh/NuyKi85UnNoyDdLoB08blefdiCKCKwkCzcWQAElNQcFcIej5wktZ0dgdw+cT5 JPaw== 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=RXhQCLR7kJ8wXIoAGktxHEJsN7Fs/rfacZeAYDKFmIs=; b=RjsfN4cihdPMhwNKI+WCULj9w9keeffnrOPn5iNANkL+kXL6OJ7JgV4pGDgiBjXHi/ UOa2quR1c9cIXyGCwkTb7uv72XKB1RgLLkQQnHyMu12XhjBkbi/V1yuX+MDK4u3Lm2O3 5KN44qIBjXr5T77NIgQkLfG9PNcG08v9bZK4UrPIzDfDinuqfmpvVPTsUAxeuVYmespu RUABJ3Si/G8cmMYo5apoYIg4CX3tfcaqzeESqB5zeEc6UIRxwN+ViTcBIF4mw6nb/fIS ar4hkpbqXs3ADKv/5LVv/kvpP9RyCFfnpgmYjA0IZ1UilX9Id6A0pBzl42kcAFZqpRqr XojA== X-Gm-Message-State: AOAM530j6zAH5H57fhkP21vt45HbPzcxzTPLcMkV5tbVyGk7Ty4sbdoW yM/Q1ohAPMlF8A7/vTLt5DG+kSOAC3aeAWL7 X-Google-Smtp-Source: ABdhPJyCc4QARongk4fah6RyGiiUm1Q5f/uw+HDYl+VU1QIrWNpifsB8yG5Y5a6N2WPCAwaf2CSaRg== X-Received: by 2002:a19:c750:: with SMTP id x77mr7443257lff.225.1610818704821; Sat, 16 Jan 2021 09:38:24 -0800 (PST) From: Odin Ugedal Cc: tj@kernel.org, lizefan@huawei.com, hannes@cmpxchg.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, dschatzberg@fb.com, surenb@google.com, Odin Ugedal Subject: [PATCH v2 2/2] cgroup: update PSI file description in docs Date: Sat, 16 Jan 2021 18:36:34 +0100 Message-Id: <20210116173634.1615875-3-odin@uged.al> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210116173634.1615875-1-odin@uged.al> References: <20210116173634.1615875-1-odin@uged.al> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable To: unlisted-recipients:; (no To-header on input) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-ZohoMail-DKIM: fail (Header signature does not verify) Content-Type: text/plain; charset="utf-8" Update PSI file description in cgroup-v2 docs to reflect the current implementation. Signed-off-by: Odin Ugedal --- Documentation/admin-guide/cgroup-v2.rst | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-= guide/cgroup-v2.rst index 63521cd36ce5..f638c9d3d9f2 100644 --- a/Documentation/admin-guide/cgroup-v2.rst +++ b/Documentation/admin-guide/cgroup-v2.rst @@ -1029,7 +1029,7 @@ All time durations are in microseconds. one number is written, $MAX is updated. =20 cpu.pressure - A read-only nested-key file which exists on non-root cgroups. + A read-only nested-keyed file. =20 Shows pressure stall information for CPU. See :ref:`Documentation/accounting/psi.rst ` for details. @@ -1475,7 +1475,7 @@ PAGE_SIZE multiple when read back. reduces the impact on the workload and memory management. =20 memory.pressure - A read-only nested-key file which exists on non-root cgroups. + A read-only nested-keyed file. =20 Shows pressure stall information for memory. See :ref:`Documentation/accounting/psi.rst ` for details. @@ -1714,7 +1714,7 @@ IO Interface Files 8:16 rbps=3D2097152 wbps=3Dmax riops=3Dmax wiops=3Dmax =20 io.pressure - A read-only nested-key file which exists on non-root cgroups. + A read-only nested-keyed file. =20 Shows pressure stall information for IO. See :ref:`Documentation/accounting/psi.rst ` for details. --=20 2.30.0