From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 B50B37E583 for ; Wed, 11 Sep 2024 20:14:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726085669; cv=none; b=Ksda0EGRCsAKc9uv4JTrwJApa/QJXkUMKpfdthBabGu7GEvF1hleFk3Vjh1WHCYshpDAsLbvj4DD6HoTdjue1A/t9u/k3wQusTCOz85Y5GdQCKq8i6E5DaMs7+I5vPkjYSkQM+hFPT7/fZ/gJgjB3oMeH+GjoqrGmmwhjTJ0Xmk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726085669; c=relaxed/simple; bh=h2kKG31g+Hmx6tmmvHaeqz9ofEgVn9kMKUL7/hoWBa0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=JAEZANj5vyGUiiur7+H/hsnHeMgYQv4GYjUUQtg85x1Wrnc80Oas5md4Iox8TxdxlWiPHeuA5OtXIYtfOmIUb23w+sGM2Z4JXUhxreiACHJKmqmVuu1Br6tzczik31xWXVkXzbXf83fw6b73Izo/N+6X8fn/GcGNp/Dd76k3ItA= 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=EmZaH6Ep; arc=none smtp.client-ip=170.10.133.124 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="EmZaH6Ep" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1726085665; 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=/KXXJVpHBqZ8jkbmiTKtUQVPTfqELx0UeolsgQNEGcI=; b=EmZaH6EpJLlM0M5vFiQlHFDr/pIfevrADJxNaXyZUtlh3QQmBGnjDirEpPkJveMLxFvcsB /cQuLOFwAlpqd5r6xOVYakwvmhokZRnHBZNR41z/nVWxba3iVvIeYbi1kiqmik+kE/+whq 5zhk2Qj+nC+B5AvDICpVGHNptbT+gHw= Received: from mx-prod-mc-05.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-558-X6QncCq1PHOuVSxOccM3SA-1; Wed, 11 Sep 2024 16:14:22 -0400 X-MC-Unique: X6QncCq1PHOuVSxOccM3SA-1 Received: from mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.15]) (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-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 532F21945109; Wed, 11 Sep 2024 20:14:20 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.45.224.43]) by mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with SMTP id E5A5D1956086; Wed, 11 Sep 2024 20:14:15 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Wed, 11 Sep 2024 22:14:08 +0200 (CEST) Date: Wed, 11 Sep 2024 22:14:02 +0200 From: Oleg Nesterov To: Linus Torvalds Cc: Roman Kisel , akpm@linux-foundation.org, apais@microsoft.com, benhill@microsoft.com, ebiederm@xmission.com, linux-kernel@vger.kernel.org, ssengar@microsoft.com, sunilmut@microsoft.com, vdso@hexbites.dev, workingjubilee@gmail.com Subject: Re: [PATCH 1/1] ptrace: Get tracer PID without reliance on the proc FS Message-ID: <20240911201402.GB16757@redhat.com> References: <20240911144412.GA16954@redhat.com> <20240911174107.1217693-1-romank@linux.microsoft.com> <20240911195311.GA16757@redhat.com> 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: User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 3.0 on 10.30.177.15 On 09/11, Linus Torvalds wrote: > > On Wed, 11 Sept 2024 at 12:54, Oleg Nesterov wrote: > > > > - please try to make your changelog more convincing. And in particular, > > please explain why !!current->ptrace is not enough and this feature > > needs the tracer's pid. > > Oleg, I realize you like the simpler patch that only has that ^^^^^^^^ No, no, I don't!!! ;) > "!!current->ptrace", but my point is that even that simpler patch is > simply WRONG, WRONG, WRONG. and I agree, agree, agree. > There is simply no valid situation where a "I have a tracer" is a good > thing to test for. Yes, yes, and that is why I added you/Eric to this discussion. I just tried to play fair. I just thought that I can't simply "nack" this change, because I can't explain why I didn't like the whole idea. Oleg.