From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 3455538D018; Wed, 29 Apr 2026 06:42:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777444924; cv=none; b=eMt7FyFw5MMhz21du9YmZk+FYQKYzT9/iozKARh202OwVd7rw7+F4LholuyvbFbFaFEz3un4xSxPHK4i/49pJ7jHC2+e6+HmrOXRpfFjztBzL05NQGKOeo+5L/ee6wPNpawrYSNLpXwaxcdo+C3dm31tHI1aoWvc9Qtb18JxLEk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777444924; c=relaxed/simple; bh=zWqxAlu/ucA1P6KiKmx97UoqK35wwC2a8fv/LnXOx3s=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=attU4WNjQF7rmB2NEHifJ4pVinD9JZ2l91O4QcniApy8STBR6LFR86pF2D0GcqbceTingMPt/xx5o5pQsYy4DFj7tjrfror5NgBLUZ3lft6X186LN613oGT9OZsHUWPFMb90sMVsR0gGPkaU0JKdPkNp5PWQ7AvvqlI4VIzVTUc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=HhvS+AEi; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="HhvS+AEi" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DD290C2BCB3; Wed, 29 Apr 2026 06:41:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1777444923; bh=zWqxAlu/ucA1P6KiKmx97UoqK35wwC2a8fv/LnXOx3s=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=HhvS+AEidghosFxYFCxxdeYV2TD2EthsWHUQvkDvugahuv/aLZPyEa4k69YelJi0G I/SpPotGYb+ehBYgUTx46f41fx74RXaOnHzFdU+4X0eoN0r3Mr+aKqFQuNdrdcF8wY A5NuVmKiDBrwafYcy3JNTmA9W9gUmuGY9RzXnH73wGaOrbQbMc5rlCjxXM/a90eRje +Xj3lD7I1TkhztOAjZhDhdffWkpa6SldLnbcXkgybnCK1+fT8xlAQG5NJp622XUyTt /W4qb0W3bIJZOgs/AkYMlbki1qEA/7PRiIFP/DjXhJ2Ph96QHMRTEtjmf0zmd7QF4G h0r1lNhnCgOUw== Date: Wed, 29 Apr 2026 08:41:53 +0200 From: Mike Rapoport To: "David Hildenbrand (Arm)" Cc: Alban Crequy , Andrew Morton , Christian Brauner , Lorenzo Stoakes , "Liam R . Howlett" , Vlastimil Babka , Suren Baghdasaryan , Michal Hocko , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Alban Crequy , Peter Xu , Willy Tarreau , linux-kselftest@vger.kernel.org, shuah@kernel.org, Usama Arif , David Laight Subject: Re: [PATCH v3 1/2] mm/process_vm_access: pidfd and nowait support for process_vm_readv/writev Message-ID: References: <20260428122826.339550-1-alban.crequy@gmail.com> <20260428122826.339550-2-alban.crequy@gmail.com> <8b29da5b-e260-4b77-a640-8abb447291d1@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8b29da5b-e260-4b77-a640-8abb447291d1@kernel.org> On Tue, Apr 28, 2026 at 10:05:49PM +0200, David Hildenbrand (Arm) wrote: > On 4/28/26 14:28, Alban Crequy wrote: > > From: Alban Crequy > > @@ -194,10 +202,18 @@ static ssize_t process_vm_rw_core(pid_t pid, struct iov_iter *iter, > > } > > > > /* Get process information */ > > - task = find_get_task_by_vpid(pid); > > - if (!task) { > > - rc = -ESRCH; > > - goto free_proc_pages; > > + if (flags & PROCESS_VM_PIDFD) { > > + task = pidfd_get_task(pid, &f_flags); > > + if (IS_ERR(task)) { > > + rc = PTR_ERR(task); > > This could return -EBADF or -ESRCH. We should document both in the man page. (or > decide to always return -ESRCH, dunno) I'm for documenting both in the man page to let userpsace see what went wrong. > -- > Cheers, > David -- Sincerely yours, Mike.