From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id F12F1C7618E for ; Sat, 22 Apr 2023 10:04:12 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pqA5p-0003lC-2r; Sat, 22 Apr 2023 06:03:46 -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 1pqA5l-0003hg-7q for qemu-devel@nongnu.org; Sat, 22 Apr 2023 06:03:41 -0400 Received: from todd.t-8ch.de ([2a01:4f8:c010:41de::1]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pqA5i-0000fE-2l for qemu-devel@nongnu.org; Sat, 22 Apr 2023 06:03:40 -0400 From: =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=t-8ch.de; s=mail; t=1682157814; bh=BAwx82WpZZmURcNDMQd8RcPycVG7QdU/ASsiJNOYjuo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KDLdT4G2hEc1gI0do1PRcYBS3Nm+bUno9RHeMOAj1wQDhN4s4xPq+FnrjbNzpL2SJ JnA1WfW1kY2Q0ECMcdSECdN/BS3/HDIQGXHV+ZhchqW1lxzAIOX8z7/b3KWTqYo3Cv NxHOS/RU4Bngs1xXR0m0UFmeGKlTGERjYio1ynU8= To: qemu-devel@nongnu.org Cc: =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= , "Laurent Vivier" Subject: [PATCH v2 2/2] linux-user: Don't require PROT_READ for mincore Date: Sat, 22 Apr 2023 12:03:14 +0200 Message-Id: <20230422100314.1650-3-thomas@t-8ch.de> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230422100314.1650-1-thomas@t-8ch.de> References: <20230422100314.1650-1-thomas@t-8ch.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=2a01:4f8:c010:41de::1; envelope-from=thomas@t-8ch.de; helo=todd.t-8ch.de 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, 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+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org The kernel does not require PROT_READ for addresses passed to mincore. For example the fincore(1) tool from util-linux uses PROT_NONE and currently does not work under qemu-user. Example (with fincore(1) from util-linux 2.38): $ fincore /proc/self/exe RES PAGES SIZE FILE 24K 6 22.1K /proc/self/exe $ qemu-x86_64 /usr/bin/fincore /proc/self/exe fincore: failed to do mincore: /proc/self/exe: Cannot allocate memory With this patch: $ ./build/qemu-x86_64 /usr/bin/fincore /proc/self/exe RES PAGES SIZE FILE 24K 6 22.1K /proc/self/exe Signed-off-by: Thomas Weißschuh --- linux-user/syscall.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/linux-user/syscall.c b/linux-user/syscall.c index 69f740ff98c8..5ec848b459f7 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -11897,7 +11897,7 @@ static abi_long do_syscall1(CPUArchState *cpu_env, int num, abi_long arg1, #ifdef TARGET_NR_mincore case TARGET_NR_mincore: { - void *a = lock_user(VERIFY_READ, arg1, arg2, 0); + void *a = lock_user(VERIFY_NONE, arg1, arg2, 0); if (!a) { return -TARGET_ENOMEM; } -- 2.40.0