From patchwork Wed Feb 28 20:25:13 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Richard Henderson X-Patchwork-Id: 1906004 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=linaro.org header.i=@linaro.org header.a=rsa-sha256 header.s=google header.b=znQ3y1cs; dkim-atps=neutral Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=patchwork.ozlabs.org) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4TlQr36s2Mz23fC for ; Thu, 29 Feb 2024 07:26:59 +1100 (AEDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rfQUZ-0007yU-5M; Wed, 28 Feb 2024 15:25:27 -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 1rfQUW-0007yD-TU for qemu-devel@nongnu.org; Wed, 28 Feb 2024 15:25:24 -0500 Received: from mail-pj1-x1030.google.com ([2607:f8b0:4864:20::1030]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1rfQUV-0007Lu-3O for qemu-devel@nongnu.org; Wed, 28 Feb 2024 15:25:24 -0500 Received: by mail-pj1-x1030.google.com with SMTP id 98e67ed59e1d1-29a6dcfdd30so83043a91.0 for ; Wed, 28 Feb 2024 12:25:22 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1709151921; x=1709756721; darn=nongnu.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=R78jNI3rLibNEjtOaGTlNz6g97kDn+JovIEvILiHK7Q=; b=znQ3y1csU6bp5A6J6DJ6lfTQ1vGHq/7rb5IbeOC9TzZhEGP9W67tXAiMX+btAeIdLY rcxO6/aNEvtYR090yVf3YO3iU6/hdiGZfP0+6SHQEVmEjQUsPXbPQO8hfHZa1whvLNco 5PqUoovA3GVDESkratc9QZuE+EmxIsqGBQUZh7+2vL3/S8wWPZa0yxo/0GNfsbV1cs4p 7miNzf0daRUeYEsLECdBza9hpGV6CDj4gU9PqNTHquN1DqNzVUnLzR8J/p2lZUxqF3gu ckp5wWIUuOLWbVgw1C6YnNzD4z7TXrkBpQEtAyjeuQ4hpLkIo8BuIt9hJWxs6kxWpU+Q N8rA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1709151921; x=1709756721; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=R78jNI3rLibNEjtOaGTlNz6g97kDn+JovIEvILiHK7Q=; b=sVNWFPRaOmtNSP1Prdu6so/49bCjUSJykeNQ1UN7cuh17Jjmpc+5+hCrb6oB3ij0UV QBGzPvhiyLlUEDEZVJETPw7LgCRZT3zQPBM+3rQRot3v/1qewQL0ZOoHRjyC9dzNnV9Z NqsCxjxc8v0pxjlIDjNcBD0v3nFqEVfkYMt1wGlNcXnx0XVFmCGyWA1e177wR9RjXSxG d7ElcYiE+N/vJqsrkw6sVP6Ffh/B5JQ8740WZIum5/65kiku34E6rhgo8qi86mkqac8V 4pPRpCFS6fZCSqbxj1R228sOw9UHKBjWZlGNFclnZb9sr4QGzWhhHiLWj9KVr2Om+fJw FAqQ== X-Gm-Message-State: AOJu0YwzNR8Ezn9Pr8hvy4Q34l5xurbpwiL1RT8Lzu5oShrSHaNffSWV 5aro89anKR80b+8hhhCakQ/fHsDyCM3d6HWol1w6QDtwyWiHLrucLzMDvXdFG/QYmx6dJ7rkR73 d X-Google-Smtp-Source: AGHT+IFDtD4q2TNroYCoH1ZL2WxskTVsT9xdRh5x+Y0L2T0KAov688azsH4QT79rHRYh9HGIzhDdlg== X-Received: by 2002:a17:90a:9315:b0:29a:68ad:b77e with SMTP id p21-20020a17090a931500b0029a68adb77emr232425pjo.19.1709151921247; Wed, 28 Feb 2024 12:25:21 -0800 (PST) Received: from stoup.. (098-147-055-211.res.spectrum.com. [98.147.55.211]) by smtp.gmail.com with ESMTPSA id oh5-20020a17090b3a4500b0029ab712f648sm2118499pjb.38.2024.02.28.12.25.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 28 Feb 2024 12:25:20 -0800 (PST) From: Richard Henderson To: qemu-devel@nongnu.org Cc: laurent@vivier.eu, richard.purdie@linuxfoundation.org, mjt@tls.msk.ru, iii@linux.ibm.com Subject: [PATCH v2 0/5] linux-user: Rewrite target_shmat Date: Wed, 28 Feb 2024 10:25:13 -1000 Message-Id: <20240228202518.33180-1-richard.henderson@linaro.org> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Received-SPF: pass client-ip=2607:f8b0:4864:20::1030; envelope-from=richard.henderson@linaro.org; helo=mail-pj1-x1030.google.com 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_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 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+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org There are multiple issues with the implementation of shmat(). (1) With reserved_va, which is the default for 32-on-64-bit, we mmap the entire guest address space. Unlike mmap, shmat refuses to replace an existing mapping without setting SHM_REMAP. This is the original subject of issue #115, though it quicky gets distracted by something else. (2) With target page size > host page size, and a shm area that is not a multiple of the target page size, we leave an unmapped hole that the target expects to be mapped. This is the subject of https://lore.kernel.org/qemu-devel/2no4imvz2zrar5kchz2l3oddqbgpj77jgwcuf7aritkn2ok763@i2mvpcihztho/ wherein qemu itself expects a mapping to exist, and dies in open_self_maps_2. So: reimplement the thing. Changes for v2: - Include Ilya's test case, which caught extra errors: Yay! - Include x86_64 /proc/self/maps fix, which the test triggers. - Dropped r-b for the shmat rewrite due to number of changes. r~ Based-on: <20240222204323.268539-1-richard.henderson@linaro.org> ("[PULL 00/39] tcg and linux-user patch queue") (Which is technically now out of date, waiting on the coredump rewrite to solve -Wvla werrors.) Ilya Leoshkevich (1): tests/tcg: Check that shmat() does not break /proc/self/maps Richard Henderson (4): linux-user/x86_64: Handle the vsyscall page in open_self_maps_{2,4} linux-user/loongarch64: Remove TARGET_FORCE_SHMLBA linux-user: Add strace for shmat linux-user: Rewrite target_shmat linux-user/loongarch64/target_syscall.h | 7 - linux-user/mmap.c | 172 +++++++++++++++---- linux-user/strace.c | 23 +++ linux-user/syscall.c | 16 ++ tests/tcg/multiarch/linux/linux-shmat-maps.c | 55 ++++++ linux-user/strace.list | 2 +- 6 files changed, 231 insertions(+), 44 deletions(-) create mode 100644 tests/tcg/multiarch/linux/linux-shmat-maps.c