From patchwork Tue Jul 10 03:12:28 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: QiaoChong X-Patchwork-Id: 941794 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=2001:4830:134:3::11; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=loongson.cn Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 41PnMS2M1sz9s0W for ; Tue, 10 Jul 2018 13:13:08 +1000 (AEST) Received: from localhost ([::1]:45561 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fcj5O-0002IH-1j for incoming@patchwork.ozlabs.org; Mon, 09 Jul 2018 23:13:06 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35794) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fcj50-0002IC-Q2 for qemu-devel@nongnu.org; Mon, 09 Jul 2018 23:12:43 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fcj4x-0002Ul-K3 for qemu-devel@nongnu.org; Mon, 09 Jul 2018 23:12:42 -0400 Received: from mail.loongson.cn ([114.242.206.163]:47732) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fcj4w-0002U5-QM for qemu-devel@nongnu.org; Mon, 09 Jul 2018 23:12:39 -0400 Received: from martinqiao.loongson.cn (unknown [10.50.122.95]) by mail (Coremail) with SMTP id QMiowPAx6OH_IkRbszmRAA--.58482S2; Tue, 10 Jul 2018 11:07:49 +0800 (CST) From: QiaoChong To: qemu-devel@nongnu.org Date: Tue, 10 Jul 2018 11:12:28 +0800 Message-Id: <1531192348-21056-1-git-send-email-qiaochong@loongson.cn> X-Mailer: git-send-email 2.7.4 X-CM-TRANSID: QMiowPAx6OH_IkRbszmRAA--.58482S2 X-Coremail-Antispam: 1UD129KBjvJXoWxZw1furW3XFyUKryDuw4rZrb_yoWrXw4fpF 9Iq3ZxCr4Fq3WDZFW2yw1kXr18AaykKrZakrW2vr1Ivr1SqF1I9FZ2yFy8J3W7AFW7tr1U WF15tr1Sqr45XaUanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUkG14x267AKxVWUJVW8JwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26r4j6ryUM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26r4j 6F4UM28EF7xvwVC2z280aVAFwI0_Gr1j6F4UJwA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_Gr 1j6F4UJwAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv 7VC0I7IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r 1j6r4UM4x0Y48IcxkI7VAKI48JM4x0Y48IcxkI7VAKI48G6xCjnVAKz4kxM4x0x7Aq67II x4CEVc8vx2IErcIFxwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s 026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_ Jrv_JF1lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Jr 0_Gr1lIxAIcVCF04k26cxKx2IYs7xG6rWUJVWrZr1UMIIF0xvEx4A2jsIE14v26r1j6r4U MIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIdaVFxhVjvjDU0xZFpf9x0JUxHUDUUU UU= X-CM-SenderInfo: 5tld0upkrqwqxorr0wxvrqhubq/ X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [fuzzy] X-Received-From: 114.242.206.163 Subject: [Qemu-devel] [PATCH] make pci_bridge_region_cleanup to be done in rcu queue after flatview_destroy. X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: qiaochong@loongson.cn Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" pci_bridge_region_cleanup need to done after flatview_destroy, because memory_region_unref need access memory regions in PCIBridgeWindows in flatview_destroy. here we delay pci_bridge_region_cleanup to be done in rcu queue work. bellow are gdb backtraces. oldcode mr->name will be freed in object_unparent, before flatview_destroy. 0 _int_free (av=0x7fffe00bcb20 , p=0x555556a988c0, have_lock=0) at malloc.c:3947 1 0x00007fffdfd7c53c in __GI___libc_free (mem=) at malloc.c:2968 2 0x000055555587ad73 in memory_region_finalize (obj=) at /work/work/loongson/qemu/qemu-latest/memory.c:1731 3 0x0000555555b52e52 in object_deinit (type=0x5555565a54f0, obj=0x5555567dcbf0) at qom/object.c:462 4 object_finalize (data=0x5555567dcbf0) at qom/object.c:476 5 object_unref (obj=0x5555567dcbf0) at qom/object.c:924 6 0x0000555555b51e57 in object_property_del_child (obj=0x55555695f3d0, child=child@entry=0x5555567dcbf0, errp=0x0) at qom/object.c:436 7 0x0000555555b525e4 in object_unparent (obj=obj@entry=0x5555567dcbf0) at qom/object.c:455 8 0x0000555555a7bd70 in pci_bridge_region_cleanup (w=0x5555567dca10, br=) at hw/pci/pci_bridge.c:229 9 0x0000555555a7c336 in pci_bridge_update_mappings (br=) at hw/pci/pci_bridge.c:248 10 0x0000555555a7c3ba in pci_bridge_write_config (d=0x55555695f3d0, address=4, val=44040192, len=4) at hw/pci/pci_bridge.c:272 here mr mr->owner, mr->name has been freed in object_unparent before. 0 memory_region_unref_do (mr=0x5555567dcbf0) at /work/work/loongson/qemu/qemu-latest/memory.c:296 1 0x0000555555877c49 in flatview_destroy (view=0x555557344020) at /work/work/loongson/qemu/qemu-latest/memory.c:290 2 0x0000555555c4a0ae in call_rcu_thread (opaque=) at util/rcu.c:284 3 0x00007fffe00c96ba in start_thread (arg=0x7fffd007c700) at pthread_create.c:333 4 0x00007fffdfdff41d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109 void memory_region_unref(MemoryRegion *mr) { if (mr && mr->owner) { object_unref(mr->owner); } } Signed-off-by: QiaoChong --- hw/pci/pci_bridge.c | 14 +++++++++++++- include/hw/pci/pci_bridge.h | 1 + 2 files changed, 14 insertions(+), 1 deletion(-) diff --git a/hw/pci/pci_bridge.c b/hw/pci/pci_bridge.c index 40a39f5..c080471 100644 --- a/hw/pci/pci_bridge.c +++ b/hw/pci/pci_bridge.c @@ -233,6 +233,18 @@ static void pci_bridge_region_cleanup(PCIBridge *br, PCIBridgeWindows *w) g_free(w); } +/* + * pci_bridge_region_cleanup need to done after flatview_destroy, + * because memory_region_unref need access memory regions in PCIBridgeWindows + * in flatview_destroy.Here we delay pci_bridge_region_cleanup to be done + * in rcu queue work. + */ + +static void pci_bridge_region_cleanup_schedule(PCIBridgeWindows *w) +{ + pci_bridge_region_cleanup(NULL, w); +} + void pci_bridge_update_mappings(PCIBridge *br) { PCIBridgeWindows *w = br->windows; @@ -243,7 +255,7 @@ void pci_bridge_update_mappings(PCIBridge *br) pci_bridge_region_del(br, br->windows); br->windows = pci_bridge_region_init(br); memory_region_transaction_commit(); - pci_bridge_region_cleanup(br, w); + call_rcu(w, pci_bridge_region_cleanup_schedule, rcu); } /* default write_config function for PCI-to-PCI bridge */ diff --git a/include/hw/pci/pci_bridge.h b/include/hw/pci/pci_bridge.h index 0347da5..0e1fd82 100644 --- a/include/hw/pci/pci_bridge.h +++ b/include/hw/pci/pci_bridge.h @@ -37,6 +37,7 @@ typedef struct PCIBridgeWindows PCIBridgeWindows; * as subregions. */ struct PCIBridgeWindows { + struct rcu_head rcu; MemoryRegion alias_pref_mem; MemoryRegion alias_mem; MemoryRegion alias_io;