From nobody Fri Nov 14 19:43:53 2025 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=fail; 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 1760214031299223.18062960846828; Sat, 11 Oct 2025 13:20:31 -0700 (PDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1v7g3p-0007Yt-OK; Sat, 11 Oct 2025 16:19:25 -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 1v7foz-00053b-CA; Sat, 11 Oct 2025 16:04:05 -0400 Received: from mlugg.co.uk ([104.238.170.239] helo=mail.mlugg.co.uk) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1v7fox-0006mi-8r; Sat, 11 Oct 2025 16:04:05 -0400 Received: from localhost.localdomain (7.1.8.2.8.1.e.f.f.f.e.d.0.b.e.f.f.b.9.2.0.c.b.a.0.b.8.0.1.0.0.2.ip6.arpa [IPv6:2001:8b0:abc0:29bf:feb0:deff:fe18:2817]) by mail.mlugg.co.uk (Postfix) with ESMTPSA id 7D6CB35301; Sat, 11 Oct 2025 20:03:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mlugg.co.uk; s=20200703; t=1760213038; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=dqp9t6T6HsmAajsqrOf/+9n3pprQKmod8UzZgWfRNrg=; b=sUe92/K5aNNSr/AtZm2B0iu4K6BHIxpgd/UgJVeD+1bO2LaQE/dLhyrDkGd2xkkflOWku9 mLlmPdjQEPyisITQQ7Rjp7EPLdJxCUFwrHVhOKW7VjITbPOp01ge+wDpbnzYHXiVX1bxsy nH6BhjXuRllchEmzC5IAFciCLioJNVE= From: Matthew Lugg To: qemu-devel@nongnu.org Cc: laurent@vivier.eu, qemu-stable@nongnu.org, Matthew Lugg Subject: [PATCH 1/4] linux-user: fix mremap unmapping adjacent region Date: Sat, 11 Oct 2025 21:03:34 +0100 Message-ID: <20251011200337.30258-2-mlugg@mlugg.co.uk> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251011200337.30258-1-mlugg@mlugg.co.uk> References: <20251011200337.30258-1-mlugg@mlugg.co.uk> 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=104.238.170.239; envelope-from=mlugg@mlugg.co.uk; helo=mail.mlugg.co.uk X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-Mailman-Approved-At: Sat, 11 Oct 2025 16:19:20 -0400 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-ZohoMail-DKIM: fail (Header signature does not verify) X-ZM-MESSAGEID: 1760214036494154100 Content-Type: text/plain; charset="utf-8" This typo meant that calls to `mremap` which shrink a mapping by some N bytes would, when the virtual address space was pre-reserved (e.g. 32-bit guest on 64-bit host), unmap the N bytes following the *original* mapping. Signed-off-by: Matthew Lugg Reviewed-by: Peter Maydell Reviewed-by: Richard Henderson --- linux-user/mmap.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/linux-user/mmap.c b/linux-user/mmap.c index 847092a28a..ec8392b35b 100644 --- a/linux-user/mmap.c +++ b/linux-user/mmap.c @@ -1164,7 +1164,8 @@ abi_long target_mremap(abi_ulong old_addr, abi_ulong = old_size, errno =3D ENOMEM; host_addr =3D MAP_FAILED; } else if (reserved_va && old_size > new_size) { - mmap_reserve_or_unmap(old_addr + old_size, + /* Re-reserve pages we just shrunk out of the mapping = */ + mmap_reserve_or_unmap(old_addr + new_size, old_size - new_size); } } --=20 2.51.0