From patchwork Mon Sep 25 13:13:59 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrzej Hajda X-Patchwork-Id: 13397827 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D4839CE7A94 for ; Mon, 25 Sep 2023 13:26:19 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 4EBA510E24D; Mon, 25 Sep 2023 13:26:19 +0000 (UTC) Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.43]) by gabe.freedesktop.org (Postfix) with ESMTPS id A83E510E24D for ; Mon, 25 Sep 2023 13:26:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1695648377; x=1727184377; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=Y3phxFH2l+gWamkxBycz06x54qFJ+isInMU3YYySyng=; b=B1Mi8pWcX2WFugWe6dkMuttsa8WeIfMZYhY0/K5+S3POxRS69WchraK+ Ymgekgql26V09x8SCWw0K0GFeAld+EQ2hli4jf2YFzUajP2NGDJlVxlWl HpqKGiBUPamjEd0QFEaZeituTGBI5Wdi/Tx9uFebxjx7Qg392Dn36IAii dC8b10+6gH7c+ku8bs8Gdt/PyfSBqYmzBAAZZZkZP/eKqT2zMePANh8a5 ei7LorV9GEFVaH1sQdHPPK5Yhwh+0BRpXL8zTMyDlFEyTBTNTBXGuxcQD Gi84JpmFvHsctu9a3pNF6oLaHkFsY2gCiBDjumbSbxklIwU8tHvuf5HfB w==; X-IronPort-AV: E=McAfee;i="6600,9927,10843"; a="467537228" X-IronPort-AV: E=Sophos;i="6.03,175,1694761200"; d="scan'208";a="467537228" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Sep 2023 06:14:13 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10843"; a="741918877" X-IronPort-AV: E=Sophos;i="6.03,175,1694761200"; d="scan'208";a="741918877" Received: from lab-ah.igk.intel.com (HELO lab-ah.corp.intel.com) ([10.102.138.202]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Sep 2023 06:14:10 -0700 From: Andrzej Hajda To: linux-kernel@vger.kernel.org, intel-gfx@lists.freedesktop.org, linux-mm@kvack.org, Thomas Gleixner Date: Mon, 25 Sep 2023 15:13:59 +0200 Message-Id: <20230925131359.2948827-1-andrzej.hajda@intel.com> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Organization: Intel Technology Poland sp. z o.o. - ul. Slowackiego 173, 80-298 Gdansk - KRS 101882 - NIP 957-07-52-316 Subject: [Intel-gfx] [PATCH v2] debugobjects: stop accessing objects after releasing spinlock X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Andrzej Hajda , Nirmoy Das Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" After spinlock release object can be modified/freed by concurrent thread. Using it in such case is error prone, even for printing object state. To avoid such situation local copy of the object is created if necessary. Signed-off-by: Andrzej Hajda --- v2: add missing switch breaks --- lib/debugobjects.c | 206 +++++++++++++++++++++------------------------ 1 file changed, 97 insertions(+), 109 deletions(-) diff --git a/lib/debugobjects.c b/lib/debugobjects.c index a517256a270b71..3afff2f668fc1e 100644 --- a/lib/debugobjects.c +++ b/lib/debugobjects.c @@ -620,9 +620,8 @@ static void debug_objects_fill_pool(void) static void __debug_object_init(void *addr, const struct debug_obj_descr *descr, int onstack) { - enum debug_obj_state state; struct debug_bucket *db; - struct debug_obj *obj; + struct debug_obj *obj, o; unsigned long flags; debug_objects_fill_pool(); @@ -644,23 +643,19 @@ __debug_object_init(void *addr, const struct debug_obj_descr *descr, int onstack case ODEBUG_STATE_INACTIVE: obj->state = ODEBUG_STATE_INIT; break; - - case ODEBUG_STATE_ACTIVE: - state = obj->state; - raw_spin_unlock_irqrestore(&db->lock, flags); - debug_print_object(obj, "init"); - debug_object_fixup(descr->fixup_init, addr, state); - return; - - case ODEBUG_STATE_DESTROYED: - raw_spin_unlock_irqrestore(&db->lock, flags); - debug_print_object(obj, "init"); - return; default: - break; + o = *obj; + obj = NULL; } raw_spin_unlock_irqrestore(&db->lock, flags); + + if (obj) + return; + + debug_print_object(&o, "init"); + if (o.state == ODEBUG_STATE_ACTIVE) + debug_object_fixup(descr->fixup_init, addr, o.state); } /** @@ -700,12 +695,9 @@ EXPORT_SYMBOL_GPL(debug_object_init_on_stack); */ int debug_object_activate(void *addr, const struct debug_obj_descr *descr) { - struct debug_obj o = { .object = addr, .state = ODEBUG_STATE_NOTAVAILABLE, .descr = descr }; - enum debug_obj_state state; struct debug_bucket *db; - struct debug_obj *obj; + struct debug_obj *obj, o; unsigned long flags; - int ret; if (!debug_objects_enabled) return 0; @@ -717,49 +709,47 @@ int debug_object_activate(void *addr, const struct debug_obj_descr *descr) raw_spin_lock_irqsave(&db->lock, flags); obj = lookup_object_or_alloc(addr, db, descr, false, true); - if (likely(!IS_ERR_OR_NULL(obj))) { - bool print_object = false; - + if (unlikely(!obj)) { + raw_spin_unlock_irqrestore(&db->lock, flags); + debug_objects_oom(); + return 0; + } else if (likely(!IS_ERR(obj))) { switch (obj->state) { case ODEBUG_STATE_INIT: case ODEBUG_STATE_INACTIVE: obj->state = ODEBUG_STATE_ACTIVE; - ret = 0; break; - case ODEBUG_STATE_ACTIVE: - state = obj->state; - raw_spin_unlock_irqrestore(&db->lock, flags); - debug_print_object(obj, "activate"); - ret = debug_object_fixup(descr->fixup_activate, addr, state); - return ret ? 0 : -EINVAL; - case ODEBUG_STATE_DESTROYED: - print_object = true; - ret = -EINVAL; + o = *obj; + obj = NULL; break; default: - ret = 0; break; } - raw_spin_unlock_irqrestore(&db->lock, flags); - if (print_object) - debug_print_object(obj, "activate"); - return ret; + } else { + o.object = addr; + o.state = ODEBUG_STATE_NOTAVAILABLE; + o.descr = descr; + obj = NULL; } raw_spin_unlock_irqrestore(&db->lock, flags); - /* If NULL the allocation has hit OOM */ - if (!obj) { - debug_objects_oom(); + if (obj) return 0; - } - /* Object is neither static nor tracked. It's not initialized */ debug_print_object(&o, "activate"); - ret = debug_object_fixup(descr->fixup_activate, addr, ODEBUG_STATE_NOTAVAILABLE); - return ret ? 0 : -EINVAL; + + switch (o.state) { + case ODEBUG_STATE_ACTIVE: + case ODEBUG_STATE_NOTAVAILABLE: + if (debug_object_fixup(descr->fixup_activate, addr, o.state)) + return 0; + fallthrough; + default: + return -EINVAL; + } } EXPORT_SYMBOL_GPL(debug_object_activate); @@ -771,9 +761,8 @@ EXPORT_SYMBOL_GPL(debug_object_activate); void debug_object_deactivate(void *addr, const struct debug_obj_descr *descr) { struct debug_bucket *db; - struct debug_obj *obj; + struct debug_obj *obj, o; unsigned long flags; - bool print_object = false; if (!debug_objects_enabled) return; @@ -788,30 +777,29 @@ void debug_object_deactivate(void *addr, const struct debug_obj_descr *descr) case ODEBUG_STATE_INIT: case ODEBUG_STATE_INACTIVE: case ODEBUG_STATE_ACTIVE: - if (!obj->astate) + if (!obj->astate) { obj->state = ODEBUG_STATE_INACTIVE; - else - print_object = true; - break; - + break; + } + fallthrough; case ODEBUG_STATE_DESTROYED: - print_object = true; + o = *obj; + obj = NULL; break; default: break; } + } else { + o.object = addr; + o.state = ODEBUG_STATE_NOTAVAILABLE; + o.descr = descr; + obj = NULL; } raw_spin_unlock_irqrestore(&db->lock, flags); - if (!obj) { - struct debug_obj o = { .object = addr, - .state = ODEBUG_STATE_NOTAVAILABLE, - .descr = descr }; + if (!obj) debug_print_object(&o, "deactivate"); - } else if (print_object) { - debug_print_object(obj, "deactivate"); - } } EXPORT_SYMBOL_GPL(debug_object_deactivate); @@ -822,11 +810,9 @@ EXPORT_SYMBOL_GPL(debug_object_deactivate); */ void debug_object_destroy(void *addr, const struct debug_obj_descr *descr) { - enum debug_obj_state state; struct debug_bucket *db; - struct debug_obj *obj; + struct debug_obj *obj, o; unsigned long flags; - bool print_object = false; if (!debug_objects_enabled) return; @@ -836,8 +822,10 @@ void debug_object_destroy(void *addr, const struct debug_obj_descr *descr) raw_spin_lock_irqsave(&db->lock, flags); obj = lookup_object(addr, db); - if (!obj) - goto out_unlock; + if (!obj) { + raw_spin_unlock_irqrestore(&db->lock, flags); + return; + } switch (obj->state) { case ODEBUG_STATE_NONE: @@ -846,22 +834,23 @@ void debug_object_destroy(void *addr, const struct debug_obj_descr *descr) obj->state = ODEBUG_STATE_DESTROYED; break; case ODEBUG_STATE_ACTIVE: - state = obj->state; - raw_spin_unlock_irqrestore(&db->lock, flags); - debug_print_object(obj, "destroy"); - debug_object_fixup(descr->fixup_destroy, addr, state); - return; - case ODEBUG_STATE_DESTROYED: - print_object = true; + o = *obj; + obj = NULL; break; default: break; } -out_unlock: + raw_spin_unlock_irqrestore(&db->lock, flags); - if (print_object) - debug_print_object(obj, "destroy"); + + if (obj) + return; + + debug_print_object(&o, "destroy"); + + if (o.state == ODEBUG_STATE_ACTIVE) + debug_object_fixup(descr->fixup_destroy, addr, o.state); } EXPORT_SYMBOL_GPL(debug_object_destroy); @@ -872,9 +861,8 @@ EXPORT_SYMBOL_GPL(debug_object_destroy); */ void debug_object_free(void *addr, const struct debug_obj_descr *descr) { - enum debug_obj_state state; struct debug_bucket *db; - struct debug_obj *obj; + struct debug_obj *obj, o; unsigned long flags; if (!debug_objects_enabled) @@ -885,24 +873,29 @@ void debug_object_free(void *addr, const struct debug_obj_descr *descr) raw_spin_lock_irqsave(&db->lock, flags); obj = lookup_object(addr, db); - if (!obj) - goto out_unlock; + if (!obj) { + raw_spin_unlock_irqrestore(&db->lock, flags); + return; + } switch (obj->state) { case ODEBUG_STATE_ACTIVE: - state = obj->state; - raw_spin_unlock_irqrestore(&db->lock, flags); - debug_print_object(obj, "free"); - debug_object_fixup(descr->fixup_free, addr, state); - return; + o = *obj; + obj = NULL; + break; default: hlist_del(&obj->node); - raw_spin_unlock_irqrestore(&db->lock, flags); + } + + raw_spin_unlock_irqrestore(&db->lock, flags); + + if (obj) { free_object(obj); return; } -out_unlock: - raw_spin_unlock_irqrestore(&db->lock, flags); + + debug_print_object(&o, "free"); + debug_object_fixup(descr->fixup_free, addr, o.state); } EXPORT_SYMBOL_GPL(debug_object_free); @@ -955,9 +948,8 @@ debug_object_active_state(void *addr, const struct debug_obj_descr *descr, unsigned int expect, unsigned int next) { struct debug_bucket *db; - struct debug_obj *obj; + struct debug_obj *obj, o; unsigned long flags; - bool print_object = false; if (!debug_objects_enabled) return; @@ -970,28 +962,27 @@ debug_object_active_state(void *addr, const struct debug_obj_descr *descr, if (obj) { switch (obj->state) { case ODEBUG_STATE_ACTIVE: - if (obj->astate == expect) + if (obj->astate == expect) { obj->astate = next; - else - print_object = true; - break; - + break; + } + fallthrough; default: - print_object = true; + o = *obj; + obj = NULL; break; } + } else { + o.object = addr; + o.state = ODEBUG_STATE_NOTAVAILABLE; + o.descr = descr; + obj = NULL; } raw_spin_unlock_irqrestore(&db->lock, flags); - if (!obj) { - struct debug_obj o = { .object = addr, - .state = ODEBUG_STATE_NOTAVAILABLE, - .descr = descr }; + if (!obj) debug_print_object(&o, "active_state"); - } else if (print_object) { - debug_print_object(obj, "active_state"); - } } EXPORT_SYMBOL_GPL(debug_object_active_state); @@ -999,11 +990,9 @@ EXPORT_SYMBOL_GPL(debug_object_active_state); static void __debug_check_no_obj_freed(const void *address, unsigned long size) { unsigned long flags, oaddr, saddr, eaddr, paddr, chunks; - const struct debug_obj_descr *descr; - enum debug_obj_state state; struct debug_bucket *db; struct hlist_node *tmp; - struct debug_obj *obj; + struct debug_obj *obj, o; int cnt, objs_checked = 0; saddr = (unsigned long) address; @@ -1026,12 +1015,11 @@ static void __debug_check_no_obj_freed(const void *address, unsigned long size) switch (obj->state) { case ODEBUG_STATE_ACTIVE: - descr = obj->descr; - state = obj->state; + o = *obj; raw_spin_unlock_irqrestore(&db->lock, flags); - debug_print_object(obj, "free"); - debug_object_fixup(descr->fixup_free, - (void *) oaddr, state); + debug_print_object(&o, "free"); + debug_object_fixup(o.descr->fixup_free, + (void *) oaddr, o.state); goto repeat; default: hlist_del(&obj->node);