From patchwork Sun Jun 25 23:17:50 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sergey Bugaev X-Patchwork-Id: 71647 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 879B33857727 for ; Sun, 25 Jun 2023 23:18:35 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 879B33857727 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1687735115; bh=NIOyXxLgUu6KWSFKDLh3q6MQA96VHsKXKsCRDdInXCI=; h=To:Subject:Date:In-Reply-To:References:List-Id:List-Unsubscribe: List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To: From; b=ofM6NA2xqeQ4U/9Gjqn/uXt4UBNGCRpNiaIT9SdMTUeszNq8UR24gBNxzSkuTI61y l1hR33isznmil3V2QpmQgPfncNOhao6TjI5iDtKX/TVyTNC1rr8z+QOL+L6YgpZ2o/ EfYQhhX7U50nEy9vi3fZ4tfhX0QMFrP0gTGZZPZA= X-Original-To: libc-alpha@sourceware.org Delivered-To: libc-alpha@sourceware.org Received: from mail-lf1-x136.google.com (mail-lf1-x136.google.com [IPv6:2a00:1450:4864:20::136]) by sourceware.org (Postfix) with ESMTPS id 3CBBC3858D37 for ; Sun, 25 Jun 2023 23:18:05 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 3CBBC3858D37 Received: by mail-lf1-x136.google.com with SMTP id 2adb3069b0e04-4f766777605so3268413e87.1 for ; Sun, 25 Jun 2023 16:18:05 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1687735083; x=1690327083; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=NIOyXxLgUu6KWSFKDLh3q6MQA96VHsKXKsCRDdInXCI=; b=SB5dbEGdv9Ho6vcd81XzWsrgql2LVMdnYu8RpuAUO7ijSZm6L9yK0B1OfTAghNW168 xJ9wqQVn8pVfym7X4ME+Tm4cLNnNqZ4uj9qOVoEvPn8Hf3d/koQAAIDwM0HZSsnXvLIw LhpkHmstvU8ICPpuDx9MZIWVrMr9pUBYAb4xFdRujVrziwR4d4jWW/AnhdnZxib+pJal fzuIO1cajqzoyB3TkhTeo5aRpCuqQBBn/Umj2VjIVY8yV6brK37G7dIA8cRXVnODeE2M iUv3ZN6nmGMTCx39h7uaxGD2Du/lSWzFh6NWqB3Ufc0hvheJsAL8uYHF/AQpj+6jddIn 3Vwg== X-Gm-Message-State: AC+VfDyeNAzeBk1jBgj4lRhdNlzz3YuahGiKNsxzBj1S/Gygr+pR7eY3 9n9+QbjiIj1Nl7oXx/tv2Il11EQUIDM= X-Google-Smtp-Source: ACHHUZ7KFPRXw2LjnM5vso5GKAIj/SvtAYARoMyBq7tUBkIPjsZ0Dju/Np0FBifcSGx2NTHSC6uAPA== X-Received: by 2002:a19:3813:0:b0:4f8:7697:5207 with SMTP id f19-20020a193813000000b004f876975207mr10545491lfa.23.1687735083357; Sun, 25 Jun 2023 16:18:03 -0700 (PDT) Received: from localhost.localdomain ([2a02:2168:b344:a600:4435:f106:1598:d2b0]) by smtp.gmail.com with ESMTPSA id eq6-20020a056512488600b004f86d546458sm851547lfb.6.2023.06.25.16.18.02 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 25 Jun 2023 16:18:02 -0700 (PDT) To: libc-alpha@sourceware.org, bug-hurd@gnu.org Subject: [PATCH 4/5] hurd: Fix mapping at address 0 with MAP_FIXED Date: Mon, 26 Jun 2023 02:17:50 +0300 Message-ID: <20230625231751.404120-4-bugaevc@gmail.com> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230625231751.404120-1-bugaevc@gmail.com> References: <20230625231751.404120-1-bugaevc@gmail.com> MIME-Version: 1.0 X-Spam-Status: No, score=-11.1 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, FREEMAIL_FROM, GIT_PATCH_0, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-Patchwork-Original-From: Sergey Bugaev via Libc-alpha From: Sergey Bugaev Reply-To: Sergey Bugaev Errors-To: libc-alpha-bounces+patchwork=sourceware.org@sourceware.org Sender: "Libc-alpha" Zero address passed to mmap () typically means the caller doesn't have any specific preferred address. Not so if MAP_FIXED is passed: in this case 0 means literal 0. Fix this case to pass anywhere = 0 into vm_map. Also add some documentation. Signed-off-by: Sergey Bugaev --- sysdeps/mach/hurd/mmap.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/sysdeps/mach/hurd/mmap.c b/sysdeps/mach/hurd/mmap.c index 5aa70083..33672cf6 100644 --- a/sysdeps/mach/hurd/mmap.c +++ b/sysdeps/mach/hurd/mmap.c @@ -38,7 +38,7 @@ __mmap (void *addr, size_t len, int prot, int flags, int fd, off_t offset) vm_prot_t vmprot, max_vmprot; memory_object_t memobj; vm_address_t mapaddr, mask; - boolean_t copy; + boolean_t copy, anywhere; mapaddr = (vm_address_t) addr; @@ -55,6 +55,7 @@ __mmap (void *addr, size_t len, int prot, int flags, int fd, off_t offset) vmprot |= VM_PROT_EXECUTE; copy = ! (flags & MAP_SHARED); + anywhere = ! (flags & MAP_FIXED); #ifdef __LP64__ if ((addr == NULL) && (prot & PROT_EXEC) @@ -141,9 +142,12 @@ __mmap (void *addr, size_t len, int prot, int flags, int fd, off_t offset) if (copy) max_vmprot = VM_PROT_ALL; + /* When ANYWHERE is true but the caller has provided a preferred address, + try mapping at that address with anywhere = 0 first. If this fails, + we'll retry with anywhere = 1 below. */ err = __vm_map (__mach_task_self (), &mapaddr, (vm_size_t) len, mask, - mapaddr == 0, + anywhere && (mapaddr == 0), memobj, (vm_offset_t) offset, copy, vmprot, max_vmprot, copy ? VM_INHERIT_COPY : VM_INHERIT_SHARE); @@ -165,7 +169,10 @@ __mmap (void *addr, size_t len, int prot, int flags, int fd, off_t offset) } else { + /* This mmap call is allowed to allocate anywhere, */ if (mapaddr != 0 && (err == KERN_NO_SPACE || err == KERN_INVALID_ADDRESS)) + /* ...but above, we tried allocating at the specific address, + and failed to. Now try again, with anywhere = 1 this time. */ err = __vm_map (__mach_task_self (), &mapaddr, (vm_size_t) len, mask, 1, memobj, (vm_offset_t) offset,