From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from wout4-smtp.messagingengine.com (wout4-smtp.messagingengine.com [64.147.123.20]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0C3802589 for ; Thu, 24 Nov 2022 13:18:25 +0000 (UTC) Received: from compute3.internal (compute3.nyi.internal [10.202.2.43]) by mailout.west.internal (Postfix) with ESMTP id 2DE6F32009C6; Thu, 24 Nov 2022 08:18:24 -0500 (EST) Received: from imap51 ([10.202.2.101]) by compute3.internal (MEProxy); Thu, 24 Nov 2022 08:18:25 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arndb.de; h=cc :cc:content-type:date:date:from:from:in-reply-to:in-reply-to :message-id:mime-version:references:reply-to:sender:subject :subject:to:to; s=fm3; t=1669295903; x=1669382303; bh=4sKDJSN01P eIAiXQHaFqrZQX8gqaur58q7xvYuCCrEw=; b=DY52+Je6rlB55h4gnvNU+KhxnG +fF14yFdZ9YMTXe5RWTtb96nPdiXE9b7ZuQdIIAIjm6lYLqDt9kPoRLIOehaNBSo uhqHJSd6MZkq3jxyzQe5d0cY8EgbXyc3ANDEmkwGlILJIdVXhjKEILq9eue1QYr+ SmrZEjlJMQt2div+xHqZ1xkJsUafpE5v/PkUxFF5mkPVw9rdk53Yfjgg7GaptpdQ tDw0ppZyl7Sp6dcw0hrWsLHhWLcUSc4mg8Y55NLkUgmeY9aomx8hsYnS20YAcPus NrJ0NIdALlEANOQ6t11fJppwBnfPmhQboDsSVbSjSnyI4jNOX36rh9HmbVXw== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-type:date:date:feedback-id :feedback-id:from:from:in-reply-to:in-reply-to:message-id :mime-version:references:reply-to:sender:subject:subject:to:to :x-me-proxy:x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s= fm1; t=1669295903; x=1669382303; bh=4sKDJSN01PeIAiXQHaFqrZQX8gqa ur58q7xvYuCCrEw=; b=cHUsDg9USKksVIE/uaaxz8YGUoQJXPIPFXFBdKtr+8UR F/M6SjrokoS65iGn6reMTGQxDxGUR0EuTTT8r+xwNZWpdXSGb27fy3FIfuJKhq1b nIacplD12qe56DgdU0LqprZz22yJlLhjnuLw+0RQbZ6LGbGFD4oco+aIVAj1ujDF KZGgYQsDcXVYdR83TXItpaY7vN5eh3UWLbAjZgv6CVUhUP6uC5HMwnfMJyZolwJ6 KpqKODvNXLYJ0F0rYpnyVz8Uy+jFUzOhM+/hK4eagtjChnMaUwjgW5kv2KW0QBfU bdxfn2ii6N2So5jluJ3V9u4NXMGFZLCOeLcSjQNq+w== X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvgedrieefgdehudcutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenuc fjughrpefofgggkfgjfhffhffvvefutgesthdtredtreertdenucfhrhhomhepfdetrhhn ugcuuegvrhhgmhgrnhhnfdcuoegrrhhnugesrghrnhgusgdruggvqeenucggtffrrghtth gvrhhnpeevhfffledtgeehfeffhfdtgedvheejtdfgkeeuvefgudffteettdekkeeufeeh udenucffohhmrghinhepkhgvrhhnvghlrdhorhhgnecuvehluhhsthgvrhfuihiivgeptd enucfrrghrrghmpehmrghilhhfrhhomheprghrnhgusegrrhhnuggsrdguvg X-ME-Proxy: Feedback-ID: i56a14606:Fastmail Received: by mailuser.nyi.internal (Postfix, from userid 501) id 6A8E8B60086; Thu, 24 Nov 2022 08:18:23 -0500 (EST) X-Mailer: MessagingEngine.com Webmail Interface User-Agent: Cyrus-JMAP/3.7.0-alpha0-1115-g8b801eadce-fm-20221102.001-g8b801ead Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Message-Id: <7928bec7-4659-4b32-aad7-2300409ea670@app.fastmail.com> In-Reply-To: References: <20221121152909.3414096-1-Jason@zx2c4.com> <20221121152909.3414096-2-Jason@zx2c4.com> <87v8n6lzh9.fsf@oldenburg.str.redhat.com> <87a64g7wks.fsf@oldenburg.str.redhat.com> <87cz9c5z1f.fsf@oldenburg.str.redhat.com> Date: Thu, 24 Nov 2022 14:18:03 +0100 From: "Arnd Bergmann" To: "Jason A . Donenfeld" , "Florian Weimer" Cc: linux-kernel@vger.kernel.org, patches@lists.linux.dev, "Thomas Gleixner" , linux-crypto@vger.kernel.org, x86@kernel.org, "Greg Kroah-Hartman" , "Adhemerval Zanella Netto" , "Carlos O'Donell" , linux-api@vger.kernel.org Subject: Re: [PATCH v6 1/3] random: add vgetrandom_alloc() syscall Content-Type: text/plain On Thu, Nov 24, 2022, at 13:48, Jason A. Donenfeld wrote: > On Thu, Nov 24, 2022 at 01:24:42PM +0100, Jason A. Donenfeld wrote: > Looks like set_mempolicy, get_mempoliy, and migrate_pages pass an > unsigned long pointer and I don't see any compat stuff around it: > > SYSCALL_DEFINE3(set_mempolicy, int, mode, const unsigned long > __user *, nmask, > unsigned long, maxnode) > > SYSCALL_DEFINE5(get_mempolicy, int __user *, policy, > unsigned long __user *, nmask, unsigned long, maxnode, > unsigned long, addr, unsigned long, flags) > > SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode, > const unsigned long __user *, old_nodes, > const unsigned long __user *, new_nodes) Compat handling for these is done all the way down in the pointer access: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/mm/mempolicy.c#n1368 This works here because it's a special bitmap but is not the best approach if you just have a pointer to a single value. Arnd