From nobody Fri Nov 14 23:31:27 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 1759683021242671.524298615164; Sun, 5 Oct 2025 09:50:21 -0700 (PDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1v5Rvq-0001nk-Vw; Sun, 05 Oct 2025 12:49:59 -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 1v5Rvo-0001lq-Vv; Sun, 05 Oct 2025 12:49:57 -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 1v5Rvm-00078K-SY; Sun, 05 Oct 2025 12:49:56 -0400 Received: from tsrv.corpit.ru (tsrv.tls.msk.ru [192.168.177.2]) by isrv.corpit.ru (Postfix) with ESMTP id 1029A15AA3F; Sun, 05 Oct 2025 19:49:27 +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 154EC2996F7; Sun, 5 Oct 2025 19:49:30 +0300 (MSK) From: Michael Tokarev To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, Peter Maydell , David Hildenbrand , Peter Xu , Michael Tokarev Subject: [Stable-10.1.1 78/81] include/system/memory.h: Clarify address_space_destroy() behaviour Date: Sun, 5 Oct 2025 19:47:58 +0300 Message-ID: <20251005164822.442861-18-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: 1759683025420116600 Content-Type: text/plain; charset="utf-8" From: Peter Maydell address_space_destroy() doesn't actually immediately destroy the AS; it queues it to be destroyed via RCU. This means you can't g_free() the memory the AS struct is in until that has happened. Clarify this in the documentation. Signed-off-by: Peter Maydell Reviewed-by: David Hildenbrand Link: https://lore.kernel.org/r/20250929144228.1994037-2-peter.maydell@lina= ro.org Signed-off-by: Peter Xu (cherry picked from commit 9e7bfda4909cc688dd0327e17985019f08a78d5d) (Mjt: this is just a comment fix, but it makes subsequent changes to apply c leanly) Signed-off-by: Michael Tokarev diff --git a/include/system/memory.h b/include/system/memory.h index e2cd6ed126..30888daaeb 100644 --- a/include/system/memory.h +++ b/include/system/memory.h @@ -2715,9 +2715,14 @@ void address_space_init(AddressSpace *as, MemoryRegi= on *root, const char *name); /** * address_space_destroy: destroy an address space * - * Releases all resources associated with an address space. After an addr= ess space - * is destroyed, its root memory region (given by address_space_init()) ma= y be destroyed - * as well. + * Releases all resources associated with an address space. After an + * address space is destroyed, the reference the AddressSpace had to + * its root memory region is dropped, which may result in the + * destruction of that memory region as well. + * + * 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. * * @as: address space to be destroyed */ --=20 2.47.3