From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 CFC3B13CA81 for ; Fri, 17 Jan 2025 14:46:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737125198; cv=none; b=cxEeQXITkx4C1YfV9I+Y6OLp40A19GRzkm95JDPejHn0B4jjpe4iMUp2Wg2WsdB7TcQmTGEM3JkUJUDn1v57jQCZGh1bYKVXGRMhgvuN6E7VXAyJUoBt6HCxkGmUvPwIWJTT4hRJriEAbA+BHUZid16qn2L4XtVmXJzL2WiknWk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737125198; c=relaxed/simple; bh=79F3g34ZyoaizTkt+l5N505iuzpx8fOb+zBwSMSnXR4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=jkDuQV1KgyTvaQS+YTGeslNcF9CItnBkip8k8IroRZiYLubH1qEudiKbi6rg6dBJnEAtbDWMH9PzjZzCb6QdEamucuLVBpbj8rmg6VwuV0CzsFyUqt33G6Q5gfn7yIbcF2Pv8YOtLmQopRZgdxfntYJl67x55SbrSmRuXnXHZ+s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=ZHiiO00Q; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="ZHiiO00Q" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1737125195; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=O1NxxkV1zamccnT9i2dReMawvJ39MRoDX74HC64YTmA=; b=ZHiiO00QItjleYVVHtbv5uGwqpSBn55WU2W9iIY1BXhfNdQgoxuNCZJAuMNKb1E1ElocR0 FNTec0o+8mld8PP6VwnqiRXex4vHxkvPQS4xg8t6blubnPP1G4OOgUbqnaimjdDks7CUXI R/iHa6n0QTYG9tcPXgMzucUt0WPTML0= Received: from mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-161-gz4dCDV2Pt-ZouLUoFI3JQ-1; Fri, 17 Jan 2025 09:46:30 -0500 X-MC-Unique: gz4dCDV2Pt-ZouLUoFI3JQ-1 X-Mimecast-MFC-AGG-ID: gz4dCDV2Pt-ZouLUoFI3JQ Received: from mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.40]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id A14C7195605E; Fri, 17 Jan 2025 14:46:28 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.45.224.118]) by mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with SMTP id 7393919560BF; Fri, 17 Jan 2025 14:46:24 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Fri, 17 Jan 2025 15:46:03 +0100 (CET) Date: Fri, 17 Jan 2025 15:45:57 +0100 From: Oleg Nesterov To: "Dmitry V. Levin" Cc: Eugene Syromyatnikov , Mike Frysinger , Renzo Davoli , Davide Berardi , strace-devel@lists.strace.io, linux-kernel@vger.kernel.org, linux-api@vger.kernel.org Subject: Re: [PATCH v2 6/7] ptrace: introduce PTRACE_SET_SYSCALL_INFO request Message-ID: <20250117144556.GB21203@redhat.com> References: <20250113170925.GA392@strace.io> <20250113171208.GF589@strace.io> <20250116152137.GE21801@redhat.com> <20250116160403.GA3554@strace.io> 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: <20250116160403.GA3554@strace.io> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 3.0 on 10.30.177.40 On 01/16, Dmitry V. Levin wrote: > > The idea is to use "op" to specify the operation, and "flags" to specify > future extensions to the operation. OK, > That is, the zero check implied by copy_struct_from_user() is not really > needed here since the compatibility is tracked by "op" and "flags": OK, but then why this patch uses copy_struct_from_user() ? Why can't we simply do if (user_size != PTRACE_SYSCALL_INFO_SIZE_VER0) return -EINVAL; if (copy_from_user(..., user_size)) return EFAULT; now, until we add the extensions ? Oleg.