From patchwork Thu Sep 14 20:02:35 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Karim Taha X-Patchwork-Id: 1834453 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=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20221208 header.b=BfAnnPTw; 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 4RmpLD0SWdz1yhd for ; Fri, 15 Sep 2023 06:08:52 +1000 (AEST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qgsa8-0003cS-0f; Thu, 14 Sep 2023 16:04:56 -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 1qgsa2-0003NW-8U for qemu-devel@nongnu.org; Thu, 14 Sep 2023 16:04:50 -0400 Received: from mail-wm1-x329.google.com ([2a00:1450:4864:20::329]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1qgsZo-0001aQ-ET for qemu-devel@nongnu.org; Thu, 14 Sep 2023 16:04:39 -0400 Received: by mail-wm1-x329.google.com with SMTP id 5b1f17b1804b1-401b5516104so14639535e9.2 for ; Thu, 14 Sep 2023 13:04:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1694721867; x=1695326667; darn=nongnu.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=jCqdSZt4JHZhZf+YE8oxI5TH33W7XtN+wtVE9f1Vv5E=; b=BfAnnPTw5g7nCxIL0PYATur84DIZAfqcvFT/gYHF/rhfA0PevhCBWpkOlQvOTUnJ1m WixBYx4QEvMXReGSerCWrBaTNLSh0RQGRC9+0a1Q329vd4Z+lLMCRtGVZNTlJb4c8+3b cIvygUIbLD48iar94KtvV7nffEgjBO8vY3FClwMWxwHWFxDzVy3/EqVu+xdqQTM6EGrc hBDBFVXKrUG6vUd55Ho2rO15MwnJBUypYS11wNx8PCBuMkMGJFR1ysGlQyvkSb3TB4iW BUKee38gBqQUVdxD6XwkqMltuKT4EE9krPoeE8s/Xh2zENAz7ErToMB73oXWjHMojhho EFhQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1694721867; x=1695326667; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=jCqdSZt4JHZhZf+YE8oxI5TH33W7XtN+wtVE9f1Vv5E=; b=icDmx7YdZWwKFs3t0S7N00iod+F/VEC80pCaI8bhEIprna72mRNXPhUZMm1tHqw2GF C3JmpINdxLOEwU6ciGEZPZHO91lIbt4Ay46oxEkpxbb8W2um9oiCFjlsKmn5br52q1PQ wSKkvGS3jdmM3gsqa386Sv0kAf2YaYjZVJa4dr/P2EDWqhsDSR8Yrr8Xx0adcExlF1WG JrhFUrC7kw71zbhLp9H9Yhzy9Np0wQUUNxrhyLN6tlojK2xReq2hh+KnRnIYHHWqoDCc j4m5jZm0Y41PRJK1rwmm4IR3kwEZIoXNj+5Hukk1W2fp8fiGk+cYfDaJpm0uwBz+5hzo cPlA== X-Gm-Message-State: AOJu0Yxf1VY1HRM0Lc75TsmvxFMzr2uJYdyJkj2JzJLQE8vG98cyh7TY G/oWFRN1+6lOgqdGNIcoFReNJ29Q08g= X-Google-Smtp-Source: AGHT+IFtJ4l0FZHeGVpOp+mLBaazUPGCANnOqIQL2lPS684/TpvEVRuvw4MpNfEJZ7iaP3ZwPioJpg== X-Received: by 2002:a05:600c:5108:b0:404:746e:c601 with SMTP id o8-20020a05600c510800b00404746ec601mr1815733wms.9.1694721867025; Thu, 14 Sep 2023 13:04:27 -0700 (PDT) Received: from karim.my.domain ([197.39.44.105]) by smtp.gmail.com with ESMTPSA id z7-20020a7bc7c7000000b00402bda974ddsm2851130wmk.6.2023.09.14.13.04.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 14 Sep 2023 13:04:26 -0700 (PDT) From: Karim Taha To: qemu-devel@nongnu.org Cc: imp@bsdimp.com, Richard Henderson , Karim Taha Subject: [PATCH v4 16/23] bsd-user: Implment madvise(2) to match the linux-user implementation. Date: Thu, 14 Sep 2023 23:02:35 +0300 Message-ID: <20230914200242.20148-17-kariem.taha2.7@gmail.com> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230914200242.20148-1-kariem.taha2.7@gmail.com> References: <20230914200242.20148-1-kariem.taha2.7@gmail.com> MIME-Version: 1.0 Received-SPF: pass client-ip=2a00:1450:4864:20::329; envelope-from=kariem.taha2.7@gmail.com; helo=mail-wm1-x329.google.com X-Spam_score_int: -17 X-Spam_score: -1.8 X-Spam_bar: - X-Spam_report: (-1.8 / 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, FREEMAIL_ENVFROM_END_DIGIT=0.25, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, 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+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Signed-off-by: Karim Taha Reviewed-by: Richard Henderson --- bsd-user/bsd-mem.h | 53 +++++++++++++++++++++++++++++++++++ bsd-user/freebsd/os-syscall.c | 4 +++ bsd-user/syscall_defs.h | 2 ++ 3 files changed, 59 insertions(+) diff --git a/bsd-user/bsd-mem.h b/bsd-user/bsd-mem.h index 16c22593bf..b00ab3aed8 100644 --- a/bsd-user/bsd-mem.h +++ b/bsd-user/bsd-mem.h @@ -129,6 +129,59 @@ static inline abi_long do_bsd_munlockall(void) return get_errno(munlockall()); } +/* madvise(2) */ +static inline abi_long do_bsd_madvise(abi_long arg1, abi_long arg2, + abi_long arg3) +{ + abi_ulong len; + int ret = 0; + abi_long start = arg1; + abi_long len_in = arg2; + abi_long advice = arg3; + + if (start & ~TARGET_PAGE_MASK) { + return -TARGET_EINVAL; + } + if (len_in == 0) { + return 0; + } + len = TARGET_PAGE_ALIGN(len_in); + if (len == 0 || !guest_range_valid_untagged(start, len)) { + return -TARGET_EINVAL; + } + + /* + * Most advice values are hints, so ignoring and returning success is ok. + * + * However, some advice values such as MADV_DONTNEED, are not hints and + * need to be emulated. + * + * A straight passthrough for those may not be safe because qemu sometimes + * turns private file-backed mappings into anonymous mappings. + * If all guest pages have PAGE_PASSTHROUGH set, mappings have the + * same semantics for the host as for the guest. + * + * MADV_DONTNEED is passed through, if possible. + * If passthrough isn't possible, we nevertheless (wrongly!) return + * success, which is broken but some userspace programs fail to work + * otherwise. Completely implementing such emulation is quite complicated + * though. + */ + mmap_lock(); + switch (advice) { + case MADV_DONTNEED: + if (page_check_range(start, len, PAGE_PASSTHROUGH)) { + ret = get_errno(madvise(g2h_untagged(start), len, advice)); + if (ret == 0) { + page_reset_target_data(start, start + len - 1); + } + } + } + mmap_unlock(); + + return ret; +} + /* minherit(2) */ static inline abi_long do_bsd_minherit(abi_long addr, abi_long len, abi_long inherit) diff --git a/bsd-user/freebsd/os-syscall.c b/bsd-user/freebsd/os-syscall.c index 6eaa705cd3..f5d60cf902 100644 --- a/bsd-user/freebsd/os-syscall.c +++ b/bsd-user/freebsd/os-syscall.c @@ -519,6 +519,10 @@ static abi_long freebsd_syscall(void *cpu_env, int num, abi_long arg1, ret = do_bsd_munlockall(); break; + case TARGET_FREEBSD_NR_madvise: /* madvise(2) */ + ret = do_bsd_madvise(arg1, arg2, arg3); + break; + case TARGET_FREEBSD_NR_minherit: /* minherit(2) */ ret = do_bsd_minherit(arg1, arg2, arg3); break; diff --git a/bsd-user/syscall_defs.h b/bsd-user/syscall_defs.h index 074df7bdd6..76f4856009 100644 --- a/bsd-user/syscall_defs.h +++ b/bsd-user/syscall_defs.h @@ -95,6 +95,8 @@ struct bsd_shm_regions { /* * sys/mman.h */ +#define TARGET_MADV_DONTNEED 4 /* dont need these pages */ + #define TARGET_FREEBSD_MAP_RESERVED0080 0x0080 /* previously misimplemented */ /* MAP_INHERIT */ #define TARGET_FREEBSD_MAP_RESERVED0100 0x0100 /* previously unimplemented */