From nobody Thu Nov 20 12:30:01 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 1763399492207839.1810338721992; Mon, 17 Nov 2025 09:11:32 -0800 (PST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1vL2ke-0003Oj-8p; Mon, 17 Nov 2025 12:10:52 -0500 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 1vL2kV-000398-0n for qemu-devel@nongnu.org; Mon, 17 Nov 2025 12:10:44 -0500 Received: from mlugg.co.uk ([2001:19f0:7401:8244:5400:ff:fe24:ff33] helo=mail.mlugg.co.uk) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1vL2kS-0006Ft-AT for qemu-devel@nongnu.org; Mon, 17 Nov 2025 12:10:42 -0500 Received: from localhost.localdomain (3.c.0.2.2.e.e.a.9.8.5.7.2.1.b.b.f.b.9.2.0.c.b.a.0.b.8.0.1.0.0.2.ip6.arpa [IPv6:2001:8b0:abc0:29bf:bb12:7589:aee2:20c3]) by mail.mlugg.co.uk (Postfix) with ESMTPSA id 68FCB35A1A; Mon, 17 Nov 2025 17:10:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mlugg.co.uk; s=20200703; t=1763399428; 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=wCgFAaPHpD5gNoEv09hbpHDRSkXCw2FXZqDCN4+OZNk=; b=ACjzg5neOfZAPpwEuTf391NQv6nOG/gaejiWYNHdKaGjkWCsjUb1ZWRlSAU9g4bgNyZTMC Hq2nxt1ihPwBeYgQ7XYGmWy/h3i349bugS+w1Z+hUwBEH8ljTBX6wJ7JCWHZ96cFHZyxVz miYW7svGg7K2p8GiP7W4gouunHxleU0= From: Matthew Lugg To: qemu-devel@nongnu.org Cc: laurent@vivier.eu, peter.maydell@linaro.org, Matthew Lugg Subject: [PATCH v2 1/4] linux-user: fix mremap unmapping adjacent region Date: Mon, 17 Nov 2025 17:09:51 +0000 Message-ID: <20251117170954.31451-2-mlugg@mlugg.co.uk> X-Mailer: git-send-email 2.51.2 In-Reply-To: <20251117170954.31451-1-mlugg@mlugg.co.uk> References: <20251117170954.31451-1-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=2001:19f0:7401:8244:5400:ff:fe24:ff33; 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, 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-ZohoMail-DKIM: fail (Header signature does not verify) X-ZM-MESSAGEID: 1763399496282153000 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: Richard Henderson --- linux-user/mmap.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) No changes from last revision, just rebased. diff --git a/linux-user/mmap.c b/linux-user/mmap.c index 423c77856a..ef3833a2bb 100644 --- a/linux-user/mmap.c +++ b/linux-user/mmap.c @@ -1171,7 +1171,8 @@ 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 2.51.2 From nobody Thu Nov 20 12:30:01 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 1763399465179966.6279724647702; Mon, 17 Nov 2025 09:11:05 -0800 (PST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1vL2kk-0003lq-8L; Mon, 17 Nov 2025 12:10:58 -0500 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 1vL2kV-00039s-3h for qemu-devel@nongnu.org; Mon, 17 Nov 2025 12:10:44 -0500 Received: from mlugg.co.uk ([2001:19f0:7401:8244:5400:ff:fe24:ff33] helo=mail.mlugg.co.uk) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1vL2kS-0006G4-8X for qemu-devel@nongnu.org; Mon, 17 Nov 2025 12:10:42 -0500 Received: from localhost.localdomain (3.c.0.2.2.e.e.a.9.8.5.7.2.1.b.b.f.b.9.2.0.c.b.a.0.b.8.0.1.0.0.2.ip6.arpa [IPv6:2001:8b0:abc0:29bf:bb12:7589:aee2:20c3]) by mail.mlugg.co.uk (Postfix) with ESMTPSA id 7BD8035A1C; Mon, 17 Nov 2025 17:10:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mlugg.co.uk; s=20200703; t=1763399430; 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=AWfnuXhrrYu4GZc3sZxhBSpbxAB6CnHusHek1i/jNVg=; b=FYdBPEJcKbnXiJhcEXI0LJL6vniHV2Nt4kDv6ogMZ56iavlFfeDnQv/SLFrMFaFugVI+DO JEk8SnFj5D9rccmcZ2iJr63JMbjHghSKngHci20tVUzzMBJyg2iMdQeKG8DQ5xO3G7UDQP oOPsWjQ7GOFowwFqy2C2AJLeRq03ULY= From: Matthew Lugg To: qemu-devel@nongnu.org Cc: laurent@vivier.eu, peter.maydell@linaro.org, Matthew Lugg Subject: [PATCH v2 2/4] linux-user: fix mremap errors for invalid ranges Date: Mon, 17 Nov 2025 17:09:52 +0000 Message-ID: <20251117170954.31451-3-mlugg@mlugg.co.uk> X-Mailer: git-send-email 2.51.2 In-Reply-To: <20251117170954.31451-1-mlugg@mlugg.co.uk> References: <20251117170954.31451-1-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=2001:19f0:7401:8244:5400:ff:fe24:ff33; 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, 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-ZohoMail-DKIM: fail (Header signature does not verify) X-ZM-MESSAGEID: 1763399467810153000 Content-Type: text/plain; charset="utf-8" If an address range given to `mremap` is invalid (exceeds addressing bounds on the guest), we were previously returning `ENOMEM`, which is not correct. The manpage and the Linux kernel implementation both agree that if `old_addr`/`old_size` refer to an invalid address, `EFAULT` is returned, and if `new_addr`/`new_size` refer to an invalid address, `EINVAL` is returned. Signed-off-by: Matthew Lugg --- linux-user/mmap.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) Changes from last revision: the EINVAL case has been moved before the EFAULT case in accordance with Richard's feedback. diff --git a/linux-user/mmap.c b/linux-user/mmap.c index ef3833a2bb..6163f1a0d1 100644 --- a/linux-user/mmap.c +++ b/linux-user/mmap.c @@ -1110,12 +1110,15 @@ abi_long target_mremap(abi_ulong old_addr, abi_ulon= g old_size, int prot; void *host_addr; =20 - if (!guest_range_valid_untagged(old_addr, old_size) || - ((flags & MREMAP_FIXED) && + if (((flags & MREMAP_FIXED) && !guest_range_valid_untagged(new_addr, new_size)) || ((flags & MREMAP_MAYMOVE) =3D=3D 0 && !guest_range_valid_untagged(old_addr, new_size))) { - errno =3D ENOMEM; + errno =3D EINVAL; + return -1; + } + if (!guest_range_valid_untagged(old_addr, old_size)) { + errno =3D EFAULT; return -1; } =20 --=20 2.51.2 From nobody Thu Nov 20 12:30:01 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 1763399453518273.4620996682082; Mon, 17 Nov 2025 09:10:53 -0800 (PST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1vL2kZ-0003FW-GN; Mon, 17 Nov 2025 12:10:47 -0500 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 1vL2kT-00033b-Mu for qemu-devel@nongnu.org; Mon, 17 Nov 2025 12:10:42 -0500 Received: from mlugg.co.uk ([2001:19f0:7401:8244:5400:ff:fe24:ff33] helo=mail.mlugg.co.uk) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1vL2kR-0006GB-Vm for qemu-devel@nongnu.org; Mon, 17 Nov 2025 12:10:41 -0500 Received: from localhost.localdomain (3.c.0.2.2.e.e.a.9.8.5.7.2.1.b.b.f.b.9.2.0.c.b.a.0.b.8.0.1.0.0.2.ip6.arpa [IPv6:2001:8b0:abc0:29bf:bb12:7589:aee2:20c3]) by mail.mlugg.co.uk (Postfix) with ESMTPSA id 67E4435A1F; Mon, 17 Nov 2025 17:10:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mlugg.co.uk; s=20200703; t=1763399431; 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=3sbIpdXlqwqmTBhiIu3GcMxjkWPw2uw95lJmCAqaivE=; b=H0eG4I4/fGKTdvwUZq58prOUn3tToruMVVqkstrmrJwaBrINHwHVHtA5HH7Ev8xK30wzGY uct1rebgQ8foQhVVPZBHGWd4xC6/YbKxOUeuI2nwl32L34hLdXAkjIvNQxsNvCYD62n1jJ bjcJ30/SZRJcjiicGe/2W74DwmWfNeU= From: Matthew Lugg To: qemu-devel@nongnu.org Cc: laurent@vivier.eu, peter.maydell@linaro.org, Matthew Lugg Subject: [PATCH v2 3/4] linux-user: fix reserved_va page leak in do_munmap Date: Mon, 17 Nov 2025 17:09:53 +0000 Message-ID: <20251117170954.31451-4-mlugg@mlugg.co.uk> X-Mailer: git-send-email 2.51.2 In-Reply-To: <20251117170954.31451-1-mlugg@mlugg.co.uk> References: <20251117170954.31451-1-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=2001:19f0:7401:8244:5400:ff:fe24:ff33; 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, 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-ZohoMail-DKIM: fail (Header signature does not verify) X-ZM-MESSAGEID: 1763399456574158500 Content-Type: text/plain; charset="utf-8" The old logic had an off-by-one bug. For instance, assuming 4k pages on host and guest, if 'len' is '4097' (indicating to unmap 2 pages), then 'last =3D start + 4096', so 'real_last =3D start + 4095', so ultimately 'real_len =3D 4096'. I do not believe this could cause any observable bugs in guests, because `target_munmap` page-aligns the length it passes in. However, calls to this function in `target_mremap` do not page-align the length, so those calls could "drop" pages, leading to a part of the reserved region becoming unmapped. At worst, a host allocation could get mapped into that hole, then clobbered by a new guest mapping. Signed-off-by: Matthew Lugg Reviewed-by: Richard Henderson --- linux-user/mmap.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) The refactor in the last revision has been dropped in favour of a simple two-line patch. The added 'ROUND_UP' on the first line of the diff is neces= sary to prevent the last 'for (prot =3D 0, ...' in the function from considering= a page which 'len' partially covers. diff --git a/linux-user/mmap.c b/linux-user/mmap.c index 6163f1a0d1..4bcfaf7894 100644 --- a/linux-user/mmap.c +++ b/linux-user/mmap.c @@ -1029,9 +1029,9 @@ static int mmap_reserve_or_unmap(abi_ulong start, abi= _ulong len) void *host_start; int prot; =20 - last =3D start + len - 1; + last =3D ROUND_UP(start + len, TARGET_PAGE_SIZE) - 1; real_start =3D start & -host_page_size; - real_last =3D ROUND_UP(last, host_page_size) - 1; + real_last =3D ROUND_UP(last + 1, host_page_size) - 1; =20 /* * If guest pages remain on the first or last host pages, --=20 2.51.2 From nobody Thu Nov 20 12:30:01 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 176339946249597.23024459746182; Mon, 17 Nov 2025 09:11:02 -0800 (PST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1vL2ke-0003PZ-VX; Mon, 17 Nov 2025 12:10:53 -0500 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 1vL2kV-00039w-9Z for qemu-devel@nongnu.org; Mon, 17 Nov 2025 12:10:44 -0500 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 1vL2kR-0006GE-WD for qemu-devel@nongnu.org; Mon, 17 Nov 2025 12:10:42 -0500 Received: from localhost.localdomain (3.c.0.2.2.e.e.a.9.8.5.7.2.1.b.b.f.b.9.2.0.c.b.a.0.b.8.0.1.0.0.2.ip6.arpa [IPv6:2001:8b0:abc0:29bf:bb12:7589:aee2:20c3]) by mail.mlugg.co.uk (Postfix) with ESMTPSA id 44B0635A22; Mon, 17 Nov 2025 17:10:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mlugg.co.uk; s=20200703; t=1763399432; 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=48dY3shIdyYgNL0gV9X/uYwMWrpcBOBCQO5LqUIeW8k=; b=duhMlVPFT6nKfRLiVrhLpNs/NJVkCav97jXL/0Lqm2UENwwLQMbeukzd8v1/C1jyZxX2fK Tlp/5PbGHmVKHd0EJfiG3zmr2YzgjH54Gh7yi1dtpoKYwEe5PZq+Wfs1TXNaade0vHNOS8 upZAkB/gk43MQHjp6GDlLuCPBDVv8lo= From: Matthew Lugg To: qemu-devel@nongnu.org Cc: laurent@vivier.eu, peter.maydell@linaro.org, Matthew Lugg Subject: [PATCH v2 4/4] tests: add tcg coverage for fixed mremap bugs Date: Mon, 17 Nov 2025 17:09:54 +0000 Message-ID: <20251117170954.31451-5-mlugg@mlugg.co.uk> X-Mailer: git-send-email 2.51.2 In-Reply-To: <20251117170954.31451-1-mlugg@mlugg.co.uk> References: <20251117170954.31451-1-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-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: 1763399464542158500 Content-Type: text/plain; charset="utf-8" These tests cover the first two fixes in this patch series. The final patch is not covered because the bug it fixes is not easily observable by the guest. Signed-off-by: Matthew Lugg --- tests/tcg/multiarch/test-mmap.c | 42 +++++++++++++++++++++++++++++++-- 1 file changed, 40 insertions(+), 2 deletions(-) Changes from last revision: reverted changes to stdout format to keep the p= atch focused. Note that the last line of the diff appears wrongly idented, but t= hat is actually because this file has a lot of incorrect hard tab identation, w= hile the diff correctly uses spaces. diff --git a/tests/tcg/multiarch/test-mmap.c b/tests/tcg/multiarch/test-mma= p.c index 96257f8ebe..e297f4b1e9 100644 --- a/tests/tcg/multiarch/test-mmap.c +++ b/tests/tcg/multiarch/test-mmap.c @@ -22,6 +22,7 @@ * along with this program; if not, see . */ =20 +#define _GNU_SOURCE #include #include #include @@ -41,7 +42,7 @@ do = \ } \ } while (0) =20 -unsigned char *dummybuf; +unsigned char *dummybuf; /* length is 2*pagesize */ static unsigned int pagesize; static unsigned int pagemask; int test_fd; @@ -451,9 +452,45 @@ void check_invalid_mmaps(void) fail_unless(addr =3D=3D MAP_FAILED); fail_unless(errno =3D=3D ENOMEM); =20 + /* Attempt to remap a region which exceeds the bounds of memory. */ + addr =3D mremap((void *)((uintptr_t)pagesize * 10), SIZE_MAX & ~(size_= t)pagemask, pagesize, 0); + fprintf(stdout, "%s mremap addr=3D%p", __func__, (void *)addr); + fail_unless(addr =3D=3D MAP_FAILED); + fail_unless(errno =3D=3D EFAULT); + fprintf(stdout, " passed\n"); } =20 +void check_shrink_mmaps(void) +{ + unsigned char *a, *b, *c; + a =3D mmap(NULL, pagesize * 2, PROT_READ, MAP_PRIVATE | MAP_ANONYMOUS,= -1, 0); + b =3D mmap(NULL, pagesize * 2, PROT_READ, MAP_PRIVATE | MAP_ANONYMOUS,= -1, 0); + c =3D mmap(NULL, pagesize * 2, PROT_READ, MAP_PRIVATE | MAP_ANONYMOUS,= -1, 0); + + fail_unless(a !=3D MAP_FAILED); + fail_unless(b !=3D MAP_FAILED); + fail_unless(c !=3D MAP_FAILED); + + /* Ensure we can read the full mappings */ + memcpy(dummybuf, a, 2 * pagesize); + memcpy(dummybuf, b, 2 * pagesize); + memcpy(dummybuf, c, 2 * pagesize); + + /* Shrink the middle mapping in-place; the others should be unaffected= */ + b =3D mremap(b, pagesize * 2, pagesize, 0); + fail_unless(b !=3D MAP_FAILED); + + /* Ensure we can still access all valid mappings */ + memcpy(dummybuf, a, 2 * pagesize); + memcpy(dummybuf, b, pagesize); + memcpy(dummybuf, c, 2 * pagesize); + + munmap(a, 2 * pagesize); + munmap(b, pagesize); + munmap(c, 2 * pagesize); +} + int main(int argc, char **argv) { char tempname[] =3D "/tmp/.cmmapXXXXXX"; @@ -468,7 +505,7 @@ int main(int argc, char **argv) =20 /* Assume pagesize is a power of two. */ pagemask =3D pagesize - 1; - dummybuf =3D malloc (pagesize); + dummybuf =3D malloc (pagesize * 2); printf ("pagesize=3D%u pagemask=3D%x\n", pagesize, pagemask); =20 test_fd =3D mkstemp(tempname); @@ -496,6 +533,7 @@ int main(int argc, char **argv) check_file_fixed_eof_mmaps(); check_file_unfixed_eof_mmaps(); check_invalid_mmaps(); + check_shrink_mmaps(); =20 /* Fails at the moment. */ /* check_aligned_anonymous_fixed_mmaps_collide_with_host(); */ --=20 2.51.2