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=-8.5 required=3.0 tests=INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT 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 D170CC5ACCC for ; Thu, 18 Oct 2018 17:03:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7ABDF21476 for ; Thu, 18 Oct 2018 17:03:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7ABDF21476 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728615AbeJSBE7 (ORCPT ); Thu, 18 Oct 2018 21:04:59 -0400 Received: from mail-ot1-f66.google.com ([209.85.210.66]:46969 "EHLO mail-ot1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727294AbeJSBE7 (ORCPT ); Thu, 18 Oct 2018 21:04:59 -0400 Received: by mail-ot1-f66.google.com with SMTP id o21so30445196otb.13; Thu, 18 Oct 2018 10:03:06 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=cETW7hbTpVAjv5VCuBz0OkmilWTcZUemT5Kzp8m8Bq8=; b=PNkELAodDoEuq2o3ERN6usYQuM4RKKPisPNYl1+3IyLJyVrlLUfr1OSgpKBUHuko06 KsdX6esnWYan+Cc4ctJsMKcZ/AoV1H4zJBcUN2Lv5ccj2Um5PKWk9m26HS6bdzXbUlr6 c7mw6oIVTgDmtMUIWxOe9vbZAcZ0wAGhHHflW7/J+m/QeVWkuXaSvMYcH4+0KorNipVk stI/a6xMDoIZbwuHqgpHukegxzFjO9aKcLhQ+bTEHAlH2QUwcP0BirFDrPsNVJXTDqTg L1I+9OFqfDarudKhXpoc1UV6CLtfw1OxGI99G5MhZYLS3EflZhHlaEIqe9v4AkbUeLq/ aBwQ== X-Gm-Message-State: ABuFfohfYlpknQaQm8I42IQ/lbe9u0uF8B3qUr9FKEK019Mjt9U4N6Tm gXBOHIsHfnI9fhjtilGH5A== X-Google-Smtp-Source: ACcGV63HVBX6F1IcWwcrKaQRnKvwZWcBLPpimTQ8OzIUZxxJVHPjutSTC5afwQMV7f5Q9peed6p0rw== X-Received: by 2002:a9d:3cbd:: with SMTP id z58mr20537878otc.159.1539882185222; Thu, 18 Oct 2018 10:03:05 -0700 (PDT) Received: from localhost (24-155-109-49.dyn.grandenetworks.net. [24.155.109.49]) by smtp.gmail.com with ESMTPSA id u107sm3866233otb.71.2018.10.18.10.03.04 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 18 Oct 2018 10:03:04 -0700 (PDT) Date: Thu, 18 Oct 2018 12:03:03 -0500 From: Rob Herring To: frowand.list@gmail.com Cc: Pantelis Antoniou , Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Alan Tull , Moritz Fischer , linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, devicetree@vger.kernel.org, linux-fpga@vger.kernel.org Subject: Re: [PATCH v4 01/18] of: overlay: add tests to validate kfrees from overlay removal Message-ID: <20181018170303.GA15557@bogus> References: <1539657458-24401-1-git-send-email-frowand.list@gmail.com> <1539657458-24401-2-git-send-email-frowand.list@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1539657458-24401-2-git-send-email-frowand.list@gmail.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 15, 2018 at 07:37:21PM -0700, frowand.list@gmail.com wrote: > From: Frank Rowand > > Add checks: > - attempted kfree due to refcount reaching zero before overlay > is removed > - properties linked to an overlay node when the node is removed > - node refcount > one during node removal in a changeset destroy, > if the node was created by the changeset > > After applying this patch, several validation warnings will be > reported from the devicetree unittest during boot due to > pre-existing devicetree bugs. The warnings will be similar to: > > OF: ERROR: of_node_release() overlay node /testcase-data/overlay-node/test-bus/test-unittest11/test-unittest111 contains unexpected properties > OF: ERROR: memory leak - destroy cset entry: attach overlay node /testcase-data-2/substation@100/hvac-medium-2 expected refcount 1 instead of 2. of_node_get() / of_node_put() are unbalanced for this node. These messages could be formatted more consistently. Put the path either at the beginning (after any prefix) or end. Beginning is more like a compiler error. End puts what the problem is before it's off the edge of the screen. > Signed-off-by: Frank Rowand > --- > Changes since v3: > - Add expected value of refcount for destroy cset entry error. Also > explain the cause of the error. > > drivers/of/dynamic.c | 29 +++++++++++++++++++++++++++++ > drivers/of/overlay.c | 1 + > include/linux/of.h | 15 ++++++++++----- > 3 files changed, 40 insertions(+), 5 deletions(-) > > diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c > index f4f8ed9b5454..24c97b7a050f 100644 > --- a/drivers/of/dynamic.c > +++ b/drivers/of/dynamic.c > @@ -330,6 +330,25 @@ void of_node_release(struct kobject *kobj) > if (!of_node_check_flag(node, OF_DYNAMIC)) > return; > > + if (of_node_check_flag(node, OF_OVERLAY)) { > + > + if (!of_node_check_flag(node, OF_OVERLAY_FREE_CSET)) { I worry the flags are getting unwieldy. > + /* premature refcount of zero, do not free memory */ > + pr_err("ERROR: memory leak %s() overlay node %pOF before free overlay changeset\n", > + __func__, node); > + return; > + } > + > + /* > + * If node->properties non-empty then properties were added > + * to this node either by different overlay that has not > + * yet been removed, or by a non-overlay mechanism. > + */ > + if (node->properties) > + pr_err("ERROR: %s() overlay node %pOF contains unexpected properties\n", > + __func__, node); > + } > + > property_list_free(node->properties); > property_list_free(node->deadprops); > > @@ -434,6 +453,16 @@ struct device_node *__of_node_dup(const struct device_node *np, > > static void __of_changeset_entry_destroy(struct of_changeset_entry *ce) > { > + if (ce->action == OF_RECONFIG_ATTACH_NODE && > + of_node_check_flag(ce->np, OF_OVERLAY)) { > + if (kref_read(&ce->np->kobj.kref) > 1) { > + pr_err("ERROR: memory leak - destroy cset entry: attach overlay node %pOF expected refcount 1 instead of %d. of_node_get() / of_node_put() are unbalanced for this node.\n", > + ce->np, kref_read(&ce->np->kobj.kref)); > + } else { > + of_node_set_flag(ce->np, OF_OVERLAY_FREE_CSET); > + } > + } > + > of_node_put(ce->np); > list_del(&ce->node); > kfree(ce); > diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c > index eda57ef12fd0..1176cb4b6e4e 100644 > --- a/drivers/of/overlay.c > +++ b/drivers/of/overlay.c > @@ -373,6 +373,7 @@ static int add_changeset_node(struct overlay_changeset *ovcs, > return -ENOMEM; > > tchild->parent = target_node; > + of_node_set_flag(tchild, OF_OVERLAY); > > ret = of_changeset_attach_node(&ovcs->cset, tchild); > if (ret) > diff --git a/include/linux/of.h b/include/linux/of.h > index 4d25e4f952d9..aa1dafaec6ae 100644 > --- a/include/linux/of.h > +++ b/include/linux/of.h > @@ -138,11 +138,16 @@ static inline void of_node_put(struct device_node *node) { } > extern struct device_node *of_stdout; > extern raw_spinlock_t devtree_lock; > > -/* flag descriptions (need to be visible even when !CONFIG_OF) */ > -#define OF_DYNAMIC 1 /* node and properties were allocated via kmalloc */ > -#define OF_DETACHED 2 /* node has been detached from the device tree */ > -#define OF_POPULATED 3 /* device already created for the node */ > -#define OF_POPULATED_BUS 4 /* of_platform_populate recursed to children of this node */ > +/* > + * struct device_node flag descriptions > + * (need to be visible even when !CONFIG_OF) > + */ > +#define OF_DYNAMIC 1 /* (and properties) allocated via kmalloc */ > +#define OF_DETACHED 2 /* detached from the device tree */ > +#define OF_POPULATED 3 /* device already created */ > +#define OF_POPULATED_BUS 4 /* platform bus created for children */ > +#define OF_OVERLAY 5 /* allocated for an overlay */ > +#define OF_OVERLAY_FREE_CSET 6 /* in overlay cset being freed */ > > #define OF_BAD_ADDR ((u64)-1) > > -- > Frank Rowand > 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=-8.5 required=3.0 tests=INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=unavailable 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 DA7C2C5ACCC for ; 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[24.155.109.49]) by smtp.gmail.com with ESMTPSA id u107sm3866233otb.71.2018.10.18.10.03.04 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 18 Oct 2018 10:03:04 -0700 (PDT) Date: Thu, 18 Oct 2018 12:03:03 -0500 From: Rob Herring To: frowand.list@gmail.com Subject: Re: [PATCH v4 01/18] of: overlay: add tests to validate kfrees from overlay removal Message-ID: <20181018170303.GA15557@bogus> References: <1539657458-24401-1-git-send-email-frowand.list@gmail.com> <1539657458-24401-2-git-send-email-frowand.list@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1539657458-24401-2-git-send-email-frowand.list@gmail.com> User-Agent: Mutt/1.9.4 (2018-02-28) X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: devicetree@vger.kernel.org, Alan Tull , linux-fpga@vger.kernel.org, Pantelis Antoniou , linux-kernel@vger.kernel.org, Moritz Fischer , Paul Mackerras , linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Mon, Oct 15, 2018 at 07:37:21PM -0700, frowand.list@gmail.com wrote: > From: Frank Rowand > > Add checks: > - attempted kfree due to refcount reaching zero before overlay > is removed > - properties linked to an overlay node when the node is removed > - node refcount > one during node removal in a changeset destroy, > if the node was created by the changeset > > After applying this patch, several validation warnings will be > reported from the devicetree unittest during boot due to > pre-existing devicetree bugs. The warnings will be similar to: > > OF: ERROR: of_node_release() overlay node /testcase-data/overlay-node/test-bus/test-unittest11/test-unittest111 contains unexpected properties > OF: ERROR: memory leak - destroy cset entry: attach overlay node /testcase-data-2/substation@100/hvac-medium-2 expected refcount 1 instead of 2. of_node_get() / of_node_put() are unbalanced for this node. These messages could be formatted more consistently. Put the path either at the beginning (after any prefix) or end. Beginning is more like a compiler error. End puts what the problem is before it's off the edge of the screen. > Signed-off-by: Frank Rowand > --- > Changes since v3: > - Add expected value of refcount for destroy cset entry error. Also > explain the cause of the error. > > drivers/of/dynamic.c | 29 +++++++++++++++++++++++++++++ > drivers/of/overlay.c | 1 + > include/linux/of.h | 15 ++++++++++----- > 3 files changed, 40 insertions(+), 5 deletions(-) > > diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c > index f4f8ed9b5454..24c97b7a050f 100644 > --- a/drivers/of/dynamic.c > +++ b/drivers/of/dynamic.c > @@ -330,6 +330,25 @@ void of_node_release(struct kobject *kobj) > if (!of_node_check_flag(node, OF_DYNAMIC)) > return; > > + if (of_node_check_flag(node, OF_OVERLAY)) { > + > + if (!of_node_check_flag(node, OF_OVERLAY_FREE_CSET)) { I worry the flags are getting unwieldy. > + /* premature refcount of zero, do not free memory */ > + pr_err("ERROR: memory leak %s() overlay node %pOF before free overlay changeset\n", > + __func__, node); > + return; > + } > + > + /* > + * If node->properties non-empty then properties were added > + * to this node either by different overlay that has not > + * yet been removed, or by a non-overlay mechanism. > + */ > + if (node->properties) > + pr_err("ERROR: %s() overlay node %pOF contains unexpected properties\n", > + __func__, node); > + } > + > property_list_free(node->properties); > property_list_free(node->deadprops); > > @@ -434,6 +453,16 @@ struct device_node *__of_node_dup(const struct device_node *np, > > static void __of_changeset_entry_destroy(struct of_changeset_entry *ce) > { > + if (ce->action == OF_RECONFIG_ATTACH_NODE && > + of_node_check_flag(ce->np, OF_OVERLAY)) { > + if (kref_read(&ce->np->kobj.kref) > 1) { > + pr_err("ERROR: memory leak - destroy cset entry: attach overlay node %pOF expected refcount 1 instead of %d. of_node_get() / of_node_put() are unbalanced for this node.\n", > + ce->np, kref_read(&ce->np->kobj.kref)); > + } else { > + of_node_set_flag(ce->np, OF_OVERLAY_FREE_CSET); > + } > + } > + > of_node_put(ce->np); > list_del(&ce->node); > kfree(ce); > diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c > index eda57ef12fd0..1176cb4b6e4e 100644 > --- a/drivers/of/overlay.c > +++ b/drivers/of/overlay.c > @@ -373,6 +373,7 @@ static int add_changeset_node(struct overlay_changeset *ovcs, > return -ENOMEM; > > tchild->parent = target_node; > + of_node_set_flag(tchild, OF_OVERLAY); > > ret = of_changeset_attach_node(&ovcs->cset, tchild); > if (ret) > diff --git a/include/linux/of.h b/include/linux/of.h > index 4d25e4f952d9..aa1dafaec6ae 100644 > --- a/include/linux/of.h > +++ b/include/linux/of.h > @@ -138,11 +138,16 @@ static inline void of_node_put(struct device_node *node) { } > extern struct device_node *of_stdout; > extern raw_spinlock_t devtree_lock; > > -/* flag descriptions (need to be visible even when !CONFIG_OF) */ > -#define OF_DYNAMIC 1 /* node and properties were allocated via kmalloc */ > -#define OF_DETACHED 2 /* node has been detached from the device tree */ > -#define OF_POPULATED 3 /* device already created for the node */ > -#define OF_POPULATED_BUS 4 /* of_platform_populate recursed to children of this node */ > +/* > + * struct device_node flag descriptions > + * (need to be visible even when !CONFIG_OF) > + */ > +#define OF_DYNAMIC 1 /* (and properties) allocated via kmalloc */ > +#define OF_DETACHED 2 /* detached from the device tree */ > +#define OF_POPULATED 3 /* device already created */ > +#define OF_POPULATED_BUS 4 /* platform bus created for children */ > +#define OF_OVERLAY 5 /* allocated for an overlay */ > +#define OF_OVERLAY_FREE_CSET 6 /* in overlay cset being freed */ > > #define OF_BAD_ADDR ((u64)-1) > > -- > Frank Rowand >