From nobody Fri Nov 14 23:31:23 2025 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1759686041590877.736035187664; Sun, 5 Oct 2025 10:40:41 -0700 (PDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1v5Shw-0001O8-RF; Sun, 05 Oct 2025 13:39:41 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1v5Sge-0000WJ-SI; Sun, 05 Oct 2025 13:38:22 -0400 Received: from isrv.corpit.ru ([212.248.84.144]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1v5Sgc-0004g1-4s; Sun, 05 Oct 2025 13:38:20 -0400 Received: from tsrv.corpit.ru (tsrv.tls.msk.ru [192.168.177.2]) by isrv.corpit.ru (Postfix) with ESMTP id 7936F15AA93; Sun, 05 Oct 2025 20:37:30 +0300 (MSK) Received: from think4mjt.tls.msk.ru (mjtthink.wg.tls.msk.ru [192.168.177.146]) by tsrv.corpit.ru (Postfix) with ESMTP id 8117829973E; Sun, 5 Oct 2025 20:37:34 +0300 (MSK) From: Michael Tokarev To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, Peter Xu , Peter Maydell , David Hildenbrand , Michael Tokarev Subject: [Stable-10.0.5 55/58] memory: New AS helper to serialize destroy+free Date: Sun, 5 Oct 2025 20:37:04 +0300 Message-ID: <20251005173712.445160-17-mjt@tls.msk.ru> X-Mailer: git-send-email 2.47.3 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=212.248.84.144; envelope-from=mjt@tls.msk.ru; helo=isrv.corpit.ru X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZM-MESSAGEID: 1759686047861116600 Content-Type: text/plain; charset="utf-8" From: Peter Xu If an AddressSpace has been created in its own allocated memory, cleaning it up requires first destroying the AS and then freeing the memory. Doing this doesn't work: address_space_destroy(as); g_free_rcu(as, rcu); because both address_space_destroy() and g_free_rcu() try to use the same 'rcu' node in the AddressSpace struct and the address_space_destroy hook gets overwritten. Provide a new address_space_destroy_free() function which will destroy the AS and then free the memory it uses, all in one RCU callback. (CC to stable because the next commit needs this function.) Cc: qemu-stable@nongnu.org Reviewed-by: Peter Maydell Signed-off-by: Peter Maydell Reviewed-by: David Hildenbrand Link: https://lore.kernel.org/r/20250929144228.1994037-3-peter.maydell@lina= ro.org Signed-off-by: Peter Xu (cherry picked from commit 041600e23f2fe2a9c252c9a8b26c7d147bedf982) Signed-off-by: Michael Tokarev diff --git a/include/exec/memory.h b/include/exec/memory.h index 2ad3f93344..ef6af5caee 100644 --- a/include/exec/memory.h +++ b/include/exec/memory.h @@ -2635,11 +2635,24 @@ void address_space_init(AddressSpace *as, MemoryReg= ion *root, const char *name); * Note that destruction of the AddressSpace is done via RCU; * it is therefore not valid to free the memory the AddressSpace * struct is in until after that RCU callback has completed. + * If you want to g_free() the AddressSpace after destruction you + * can do that with address_space_destroy_free(). * * @as: address space to be destroyed */ void address_space_destroy(AddressSpace *as); =20 +/** + * address_space_destroy_free: destroy an address space and free it + * + * This does the same thing as address_space_destroy(), and then also + * frees (via g_free()) the AddressSpace itself once the destruction + * is complete. + * + * @as: address space to be destroyed + */ +void address_space_destroy_free(AddressSpace *as); + /** * address_space_remove_listeners: unregister all listeners of an address = space * diff --git a/system/memory.c b/system/memory.c index 4c829793a0..94cb60c83b 100644 --- a/system/memory.c +++ b/system/memory.c @@ -3254,7 +3254,14 @@ static void do_address_space_destroy(AddressSpace *a= s) memory_region_unref(as->root); } =20 -void address_space_destroy(AddressSpace *as) +static void do_address_space_destroy_free(AddressSpace *as) +{ + do_address_space_destroy(as); + g_free(as); +} + +/* Detach address space from global view, notify all listeners */ +static void address_space_detach(AddressSpace *as) { MemoryRegion *root =3D as->root; =20 @@ -3269,9 +3276,20 @@ void address_space_destroy(AddressSpace *as) * values to expire before freeing the data. */ as->root =3D root; +} + +void address_space_destroy(AddressSpace *as) +{ + address_space_detach(as); call_rcu(as, do_address_space_destroy, rcu); } =20 +void address_space_destroy_free(AddressSpace *as) +{ + address_space_detach(as); + call_rcu(as, do_address_space_destroy_free, rcu); +} + static const char *memory_region_type(MemoryRegion *mr) { if (mr->alias) { --=20 2.47.3