From: frowand.list@gmail.com To: Rob Herring <robh+dt@kernel.org>, Pantelis Antoniou <pantelis.antoniou@konsulko.com>, Michael Ellerman <mpe@ellerman.id.au>, Benjamin Herrenschmidt <benh@kernel.crashing.org>, Paul Mackerras <paulus@samba.org>, Alan Tull <atull@kernel.org>, Moritz Fischer <mdf@kernel.org> Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, devicetree@vger.kernel.org, linux-fpga@vger.kernel.org Subject: [PATCH v5 01/18] of: overlay: add tests to validate kfrees from overlay removal Date: Thu, 18 Oct 2018 15:46:19 -0700 [thread overview] Message-ID: <1539902796-8382-2-git-send-email-frowand.list@gmail.com> (raw) In-Reply-To: <1539902796-8382-1-git-send-email-frowand.list@gmail.com> From: Frank Rowand <frank.rowand@sony.com> 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(), unexpected properties in /testcase-data/overlay-node/test-bus/test-unittest11 OF: ERROR: memory leak, expected refcount 1 instead of 2, of_node_get()/of_node_put() unbalanced - destroy cset entry: attach overlay node /testcase-data-2/substation@100/ hvac-medium-2 Signed-off-by: Frank Rowand <frank.rowand@sony.com> --- Changes since v4: - make error message format consistent, error first, path last 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..12c3f9a15e94 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)) { + /* premature refcount of zero, do not free memory */ + pr_err("ERROR: memory leak before free overlay changeset, %pOF\n", + 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(), unexpected properties in %pOF\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, expected refcount 1 instead of %d, of_node_get()/of_node_put() unbalanced - destroy cset entry: attach overlay node %pOF\n", + kref_read(&ce->np->kobj.kref), ce->np); + } 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 <frank.rowand@sony.com>
WARNING: multiple messages have this Message-ID (diff)
From: frowand.list@gmail.com To: Rob Herring <robh+dt@kernel.org>, Pantelis Antoniou <pantelis.antoniou@konsulko.com>, Michael Ellerman <mpe@ellerman.id.au>, Benjamin Herrenschmidt <benh@kernel.crashing.org>, Paul Mackerras <paulus@samba.org>, Alan Tull <atull@kernel.org>, Moritz Fischer <mdf@kernel.org> Cc: devicetree@vger.kernel.org, linux-fpga@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Subject: [PATCH v5 01/18] of: overlay: add tests to validate kfrees from overlay removal Date: Thu, 18 Oct 2018 15:46:19 -0700 [thread overview] Message-ID: <1539902796-8382-2-git-send-email-frowand.list@gmail.com> (raw) In-Reply-To: <1539902796-8382-1-git-send-email-frowand.list@gmail.com> From: Frank Rowand <frank.rowand@sony.com> 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(), unexpected properties in /testcase-data/overlay-node/test-bus/test-unittest11 OF: ERROR: memory leak, expected refcount 1 instead of 2, of_node_get()/of_node_put() unbalanced - destroy cset entry: attach overlay node /testcase-data-2/substation@100/ hvac-medium-2 Signed-off-by: Frank Rowand <frank.rowand@sony.com> --- Changes since v4: - make error message format consistent, error first, path last 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..12c3f9a15e94 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)) { + /* premature refcount of zero, do not free memory */ + pr_err("ERROR: memory leak before free overlay changeset, %pOF\n", + 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(), unexpected properties in %pOF\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, expected refcount 1 instead of %d, of_node_get()/of_node_put() unbalanced - destroy cset entry: attach overlay node %pOF\n", + kref_read(&ce->np->kobj.kref), ce->np); + } 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 <frank.rowand@sony.com>
next prev parent reply other threads:[~2018-10-18 22:48 UTC|newest] Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top 2018-10-18 22:46 [PATCH v5 00/18] of: overlay: validation checks, subsequent fixes frowand.list 2018-10-18 22:46 ` frowand.list 2018-10-18 22:46 ` frowand.list [this message] 2018-10-18 22:46 ` [PATCH v5 01/18] of: overlay: add tests to validate kfrees from overlay removal frowand.list 2018-10-18 22:46 ` [PATCH v5 02/18] of: overlay: add missing of_node_put() after add new node to changeset frowand.list 2018-10-18 22:46 ` frowand.list 2018-10-18 22:46 ` [PATCH v5 03/18] of: overlay: add missing of_node_get() in __of_attach_node_sysfs frowand.list 2018-10-18 22:46 ` frowand.list 2018-10-18 22:46 ` [PATCH v5 04/18] powerpc/pseries: add of_node_put() in dlpar_detach_node() frowand.list 2018-10-18 22:46 ` frowand.list 2018-10-18 22:46 ` [PATCH v5 05/18] of: overlay: use prop add changeset entry for property in new nodes frowand.list 2018-10-18 22:46 ` frowand.list 2018-10-18 22:46 ` [PATCH v5 06/18] of: overlay: do not duplicate properties from overlay for " frowand.list 2018-10-18 22:46 ` frowand.list 2018-10-18 22:46 ` [PATCH v5 07/18] of: dynamic: change type of of_{at,de}tach_node() to void frowand.list 2018-10-18 22:46 ` [PATCH v5 07/18] of: dynamic: change type of of_{at, de}tach_node() " frowand.list 2018-10-18 22:46 ` [PATCH v5 08/18] of: overlay: reorder fields in struct fragment frowand.list 2018-10-18 22:46 ` frowand.list 2018-10-18 22:46 ` [PATCH v5 09/18] of: overlay: validate overlay properties #address-cells and #size-cells frowand.list 2018-10-18 22:46 ` frowand.list 2018-10-18 22:46 ` [PATCH v5 10/18] of: overlay: make all pr_debug() and pr_err() messages unique frowand.list 2018-10-18 22:46 ` frowand.list 2018-10-18 22:46 ` [PATCH v5 11/18] of: overlay: test case of two fragments adding same node frowand.list 2018-10-18 22:46 ` frowand.list 2018-10-18 22:46 ` [PATCH v5 12/18] of: overlay: check prevents multiple fragments add or delete " frowand.list 2018-10-18 22:46 ` frowand.list 2018-10-18 22:46 ` [PATCH v5 13/18] of: overlay: check prevents multiple fragments touching same property frowand.list 2018-10-18 22:46 ` frowand.list 2018-10-18 22:46 ` [PATCH v5 14/18] of: unittest: remove unused of_unittest_apply_overlay() argument frowand.list 2018-10-18 22:46 ` frowand.list 2018-10-18 22:46 ` [PATCH v5 15/18] of: overlay: set node fields from properties when add new overlay node frowand.list 2018-10-18 22:46 ` frowand.list 2018-10-18 22:46 ` [PATCH v5 16/18] of: unittest: allow base devicetree to have symbol metadata frowand.list 2018-10-18 22:46 ` frowand.list 2018-10-18 22:46 ` [PATCH v5 17/18] of: unittest: find overlays[] entry by name instead of index frowand.list 2018-10-18 22:46 ` frowand.list 2018-10-18 22:46 ` [PATCH v5 18/18] of: unittest: initialize args before calling of_*parse_*() frowand.list 2018-10-18 22:46 ` frowand.list 2018-10-19 5:00 ` [PATCH v5 00/18] of: overlay: validation checks, subsequent fixes Frank Rowand 2018-10-19 5:00 ` Frank Rowand 2018-10-22 21:24 ` Alan Tull 2018-10-22 21:24 ` Alan Tull 2018-10-22 21:24 ` Alan Tull 2018-10-24 19:57 ` Rob Herring 2018-10-24 19:57 ` Rob Herring 2018-10-25 15:25 ` Alan Tull 2018-10-25 15:25 ` Alan Tull 2018-10-25 15:25 ` Alan Tull
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