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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id AB275C79F99 for ; Mon, 7 Sep 2026 20:06:35 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 770DA6B0093; Mon, 7 Sep 2026 16:06:34 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 7422A6B0095; Mon, 7 Sep 2026 16:06:34 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6316B6B0096; Mon, 7 Sep 2026 16:06:34 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 311816B0093 for ; Mon, 7 Sep 2026 16:06:34 -0400 (EDT) Received: from smtpin09.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 940A3402E9 for ; Mon, 7 Sep 2026 20:06:33 +0000 (UTC) X-FDA: 85188048666.09.B623043 Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf05.hostedemail.com (Postfix) with ESMTP id CBF5410000F for ; Mon, 7 Sep 2026 20:06:31 +0000 (UTC) Authentication-Results: imf05.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=itj8IO6W; spf=pass (imf05.hostedemail.com: domain of david@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=david@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1788811591; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=8iZFtkM4l1pBZzM0aft9DJRPxcvPbB47sa2kHkN4CLw=; b=xnE850bl2cncsX8qvE9VFZoN9H+AzFVkjRf6LyqLJs8TiwUeMdmdtVksbrZHrYZysxOfCZ CQm+OBfVs61TsJAm2/Whk2jYL2owyGTRK/eZU+cZkQgUsFqigenDuPC1LvVeec1KHrP2Co k8RS0MrLkgR5sjw8LDQFsQWdoEccxSE= ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1788811591; b=h+TfftQPHvN11GD2XQQOFVmgTNOIomDznEtS4dyoZmgJZPJrrnn+oWDPCg6tkC9qSeB0nL kTTYq5zqBFfLkAcKouv+McuQO7KISAUUGaYhkfs3KCrGvKy30Sp+C1hytmP5ma46Wo/9NG 4HiDUWeUNM2MqdhlIgt97ODHqZRHN3w= ARC-Authentication-Results: i=1; imf05.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=itj8IO6W; spf=pass (imf05.hostedemail.com: domain of david@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=david@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id CC6E043CC4; Mon, 7 Sep 2026 20:06:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E356D1F00A3A; Mon, 7 Sep 2026 20:06:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788811590; bh=8iZFtkM4l1pBZzM0aft9DJRPxcvPbB47sa2kHkN4CLw=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=itj8IO6WuGDUlG4fV19yF3V4rKpQ14rYl9UeIVKDmHnSJolv7EFD8UQxFlCdkBVGK ws9Vqsg1Z5r3sQcqqF/wAeIxdjJpCuEOH8c/snnX01Cix6RsOz8HMTuSuIxyouMrEX N9Ho7R/MyeVcbXscY7gENbyUtymnAzjTKk4/z1IDjAsYrtk1M77rWloHCt2hqKJLKo RJGm+RXuXyXLJDPqMwjCCESNFKNgKuiECjrFBmLVzhKAvOx6SXB7UFw/iN06DxwGtd PXj/TdTFDuHpUbKZBcLTJzspv/NQjcVuLM3gTFfWwF/b6764/khZWF7e+zmsWaTxUO tAY1Bek0OCNgg== Message-ID: Date: Mon, 7 Sep 2026 22:06:22 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH bpf-next v5 1/7] mm: Add copy_remote_mm_str() To: Anastasios Papagiannis , bpf@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org, andrii@kernel.org, ast@kernel.org, brauner@kernel.org, daniel@iogearbox.net, eddyz87@gmail.com, kpsingh@kernel.org, ljs@kernel.org, matt@bobrowski.net, memxor@gmail.com, song@kernel.org, sun.jian.kdev@gmail.com, utilityemal77@gmail.com, viro@zeniv.linux.org.uk References: <20260907165220.52431-1-tasos.papagiannnis@gmail.com> <20260907165220.52431-2-tasos.papagiannnis@gmail.com> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzS5EYXZpZCBIaWxk ZW5icmFuZCAoQ3VycmVudCkgPGRhdmlkQGtlcm5lbC5vcmc+wsGQBBMBCAA6AhsDBQkmWAik AgsJBBUKCQgCFgICHgUCF4AWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaYJt/AIZAQAKCRBN 3hD3AP+DWriiD/9BLGEKG+N8L2AXhikJg6YmXom9ytRwPqDgpHpVg2xdhopoWdMRXjzOrIKD g4LSnFaKneQD0hZhoArEeamG5tyo32xoRsPwkbpIzL0OKSZ8G6mVbFGpjmyDLQCAxteXCLXz ZI0VbsuJKelYnKcXWOIndOrNRvE5eoOfTt2XfBnAapxMYY2IsV+qaUXlO63GgfIOg8RBaj7x 3NxkI3rV0SHhI4GU9K6jCvGghxeS1QX6L/XI9mfAYaIwGy5B68kF26piAVYv/QZDEVIpo3t7 /fjSpxKT8plJH6rhhR0epy8dWRHk3qT5tk2P85twasdloWtkMZ7FsCJRKWscm1BLpsDn6EQ4 jeMHECiY9kGKKi8dQpv3FRyo2QApZ49NNDbwcR0ZndK0XFo15iH708H5Qja/8TuXCwnPWAcJ DQoNIDFyaxe26Rx3ZwUkRALa3iPcVjE0//TrQ4KnFf+lMBSrS33xDDBfevW9+Dk6IISmDH1R HFq2jpkN+FX/PE8eVhV68B2DsAPZ5rUwyCKUXPTJ/irrCCmAAb5Jpv11S7hUSpqtM/6oVESC 3z/7CzrVtRODzLtNgV4r5EI+wAv/3PgJLlMwgJM90Fb3CB2IgbxhjvmB1WNdvXACVydx55V7 LPPKodSTF29rlnQAf9HLgCphuuSrrPn5VQDaYZl4N/7zc2wcWM7BTQRVy5+RARAA59fefSDR 9nMGCb9LbMX+TFAoIQo/wgP5XPyzLYakO+94GrgfZjfhdaxPXMsl2+o8jhp/hlIzG56taNdt VZtPp3ih1AgbR8rHgXw1xwOpuAd5lE1qNd54ndHuADO9a9A0vPimIes78Hi1/yy+ZEEvRkHk /kDa6F3AtTc1m4rbbOk2fiKzzsE9YXweFjQvl9p+AMw6qd/iC4lUk9g0+FQXNdRs+o4o6Qvy iOQJfGQ4UcBuOy1IrkJrd8qq5jet1fcM2j4QvsW8CLDWZS1L7kZ5gT5EycMKxUWb8LuRjxzZ 3QY1aQH2kkzn6acigU3HLtgFyV1gBNV44ehjgvJpRY2cC8VhanTx0dZ9mj1YKIky5N+C0f21 zvntBqcxV0+3p8MrxRRcgEtDZNav+xAoT3G0W4SahAaUTWXpsZoOecwtxi74CyneQNPTDjNg azHmvpdBVEfj7k3p4dmJp5i0U66Onmf6mMFpArvBRSMOKU9DlAzMi4IvhiNWjKVaIE2Se9BY FdKVAJaZq85P2y20ZBd08ILnKcj7XKZkLU5FkoA0udEBvQ0f9QLNyyy3DZMCQWcwRuj1m73D sq8DEFBdZ5eEkj1dCyx+t/ga6x2rHyc8Sl86oK1tvAkwBNsfKou3v+jP/l14a7DGBvrmlYjO 59o3t6inu6H7pt7OL6u6BQj7DoMAEQEAAcLBfAQYAQgAJgIbDBYhBBvZyq1zXEw6Rg38yk3e EPcA/4NaBQJonNqrBQkmWAihAAoJEE3eEPcA/4NaKtMQALAJ8PzprBEXbXcEXwDKQu+P/vts IfUb1UNMfMV76BicGa5NCZnJNQASDP/+bFg6O3gx5NbhHHPeaWz/VxlOmYHokHodOvtL0WCC 8A5PEP8tOk6029Z+J+xUcMrJClNVFpzVvOpb1lCbhjwAV465Hy+NUSbbUiRxdzNQtLtgZzOV Zw7jxUCs4UUZLQTCuBpFgb15bBxYZ/BL9MbzxPxvfUQIPbnzQMcqtpUs21CMK2PdfCh5c4gS sDci6D5/ZIBw94UQWmGpM/O1ilGXde2ZzzGYl64glmccD8e87OnEgKnH3FbnJnT4iJchtSvx yJNi1+t0+qDti4m88+/9IuPqCKb6Stl+s2dnLtJNrjXBGJtsQG/sRpqsJz5x1/2nPJSRMsx9 5YfqbdrJSOFXDzZ8/r82HgQEtUvlSXNaXCa95ez0UkOG7+bDm2b3s0XahBQeLVCH0mw3RAQg r7xDAYKIrAwfHHmMTnBQDPJwVqxJjVNr7yBic4yfzVWGCGNE4DnOW0vcIeoyhy9vnIa3w1uZ 3iyY2Nsd7JxfKu1PRhCGwXzRw5TlfEsoRI7V9A8isUCoqE2Dzh3FvYHVeX4Us+bRL/oqareJ CIFqgYMyvHj7Q06kTKmauOe4Nf0l0qEkIuIzfoLJ3qr5UyXc2hLtWyT9Ir+lYlX9efqh7mOY qIws/H2t In-Reply-To: <20260907165220.52431-2-tasos.papagiannnis@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: CBF5410000F X-Stat-Signature: u8omorqfacrcp5xnxonxesfhy4fp5up8 X-HE-Tag: 1788811591-231687 X-HE-Meta: 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 Fm/0D9kn Q2HLi4Z3L1HHR6hRKCQLsnGdbJmIinEOwV1AX8osRBzF0haCm6A5R0C5vSM5fZiDSfWr3xKL0SIw/R+4tZPpHuARq024PBrcqsMsX2NcSgxSY0VVyZbcbYrGtfPiOdfhLHBeBLWj2TzGiEUpyNtzqmj5BjpvtQEsBUoPdL9ZKHiImc328i4dXhNmvuUSMOZKhP6TsmHOYaQddTHzVzwedqmDaPFKcXmsC9Y1jFOK60boxHPds1WtZaTS6Ji878ofs6Fb9Xo1lSsBwoZKRV3xlX7E0UD/CS8DWqy80LEyo7ZVUgKiZmJwRbCdsbQk4CCs3t+DqUAg4P2C/ILG5KI0F5QjhzHUbUh13btt0HTV6m3RAwszDevPdG8N/AIrMb+tfhB0mTSwiE5hOV9m0BMcZZ7Elag== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 9/7/26 18:52, Anastasios Papagiannis wrote: > copy_remote_vm_str() gets the target address space from a struct > task_struct. This does not work for an address space that exists but is > not yet associated with a task_struct, such as the mm held by struct > linux_binprm during exec. > > Add copy_remote_mm_str(), which operates directly on a struct mm_struct. > > Use a common internal interface for the MMU and NOMMU implementations > and define both public wrappers in mm/util.c. Preserve the existing > copy_remote_vm_str() behavior, including handling zero-length requests > before acquiring the task's mm. > > Signed-off-by: Anastasios Papagiannis > --- > include/linux/mm.h | 2 ++ > mm/internal.h | 5 ++++ > mm/memory.c | 41 ++---------------------------- > mm/nommu.c | 41 ++---------------------------- > mm/util.c | 62 ++++++++++++++++++++++++++++++++++++++++++++++ > 5 files changed, 73 insertions(+), 78 deletions(-) Almost looks like a cleanup now ;) > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index dd09c438fa23..d5bde1f71a97 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -3326,6 +3326,8 @@ extern int access_remote_vm(struct mm_struct *mm, unsigned long addr, > void *buf, int len, unsigned int gup_flags); > > #ifdef CONFIG_BPF_SYSCALL > +extern int copy_remote_mm_str(struct mm_struct *mm, unsigned long addr, > + void *buf, int len, unsigned int gup_flags); > extern int copy_remote_vm_str(struct task_struct *tsk, unsigned long addr, > void *buf, int len, unsigned int gup_flags); Ah, no new "extern" and best to drop the "extern" from the other involved function while at it. Also, you can just drop the ifdef; the linker will complain either way later. > #endif > diff --git a/mm/internal.h b/mm/internal.h > index 38b1165212c9..8264a346d18a 100644 > --- a/mm/internal.h > +++ b/mm/internal.h > @@ -25,6 +25,11 @@ > struct folio_batch; > struct hstate; > > +#ifdef CONFIG_BPF_SYSCALL > +int __copy_remote_mm_str(struct mm_struct *mm, unsigned long addr, > + void *buf, int len, unsigned int gup_flags); > +#endif > + Same here, the linker will complain, so no need for the ifdef. Apart from that LGTM, thanks! -- Cheers, David