From patchwork Mon Sep 25 09:16:00 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrzej Hajda X-Patchwork-Id: 13397560 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 AC76BCE7A89 for ; Mon, 25 Sep 2023 09:16:34 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 185DE8918D; Mon, 25 Sep 2023 09:16:34 +0000 (UTC) Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.115]) by gabe.freedesktop.org (Postfix) with ESMTPS id 995E68918D for ; Mon, 25 Sep 2023 09:16:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1695633392; x=1727169392; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=4mYYGMtvhrZ5Go/HEV8QLtGBFT/aHlbOysA0rNPlmFE=; b=Qp+XfCNr2qpMIHSKB2B1ZdMcMrvG7cwI7CVjBE3y1bSQyjdovF+Jg4yL S7199N8VFrW7huqLeUmY0Ah7gRtWXnhuS/vcRTgXEyvdlaIa06l/fJpMJ OKZ5s6dOKuQBkQzRoeE9qFDw12jXwV7D3nAbRT9aL4umcZQyI9A9zdOeb QM8lN+XMsRW0HwcSEsGp1Af5p0uni4Vd55Aa66bKW2K6JvawbESoJBAps 2iHaC5tlLiFv5oAwtbMoxkZNMliuDY8JS1vuZUN65P6vu36sJ1IGl7gUo jmlXzvD/7igg+r3/2alO0RZmU5YcR8Y1TQ8WDdMwUuwHzwdSSaUdO4ypq w==; X-IronPort-AV: E=McAfee;i="6600,9927,10843"; a="381115720" X-IronPort-AV: E=Sophos;i="6.03,174,1694761200"; d="scan'208";a="381115720" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Sep 2023 02:16:29 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10843"; a="838515025" X-IronPort-AV: E=Sophos;i="6.03,174,1694761200"; d="scan'208";a="838515025" Received: from lab-ah.igk.intel.com (HELO lab-ah.corp.intel.com) ([10.102.138.202]) by fmsmga003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Sep 2023 02:16:27 -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 11:16:00 +0200 Message-Id: <20230925091600.2941364-1-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] 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 --- lib/debugobjects.c | 208 +++++++++++++++++++++------------------------ 1 file changed, 97 insertions(+), 111 deletions(-) diff --git a/lib/debugobjects.c b/lib/debugobjects.c index a517256a270b71..d6f9af11bff0d9 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 +709,46 @@ 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; + default: + } + + return -EINVAL; } EXPORT_SYMBOL_GPL(debug_object_activate); @@ -771,9 +760,8 @@ 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 +776,29 @@ 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 +809,9 @@ 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 +821,10 @@ 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 +833,22 @@ 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 +859,8 @@ 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 +871,29 @@ 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 +946,8 @@ 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 +960,27 @@ 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 +988,9 @@ 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 +1013,11 @@ 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);