Received: by 2002:a05:6a10:9848:0:0:0:0 with SMTP id x8csp759428pxf; Thu, 1 Apr 2021 12:49:24 -0700 (PDT) X-Google-Smtp-Source: ABdhPJwWn2qCazOn4EjDJLtXawVj8tSTghyBGY6v1l1aGc8MvXizHDhcV7TD0n8CUJlIZzlvt/l8 X-Received: by 2002:a17:906:1b54:: with SMTP id p20mr10735121ejg.307.1617306564674; Thu, 01 Apr 2021 12:49:24 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1617306564; cv=none; d=google.com; s=arc-20160816; b=LGMqqVMb0uE8TmFnJMQqjtKwpa1Ba7f6GxJmgHyav3J0ssv/Jqaa6VZQZKxgmfpmHx /IWbvdtgc/z/R2B+Vm6YDxetWnB78MYp/VTGU1Nct8xULHoeWIOXAtHzkGIR6cSrnFNm Z9YkU0SI9356IyUL4jI1k3jdC6PxUrs79iLbjTce7pXj18cDwXkWRa1OUoQcULl9Hl+a IEG3RQaPDW5BU0aWdG5al0/uKPVvxH76+AFVyLQlx6KWXu4UejNevwTDZaVZFx8FI3iU HFZruionFyk5Lg7A+PAi6QIMYRSyLFvY56l1Puv+aeqtnz2O+23pS5TWBu4JqW/n4B82 Enzw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:in-reply-to:content-disposition:mime-version :references:message-id:subject:cc:to:from:date:dkim-signature; bh=Qpz5/i5ZiJKb5n7InY8CiPZlk0x+Dq7b/uIx2Bj5OpE=; b=p0Sunue1uCFM37CJd6DgEjknDy9Y7EEgPouoKnV+HeBXsp0Dk3qpuwU3idGZTeOyyk 0pNwiUE27Cn4OkFalMi9Th+UV8F1iDFx/EZnAt22Xj0ZK1Aa7Njwd2urgTYEiQXfB1DL jOg+XBOmEq4uT1wTjqrGej7CBpgnk9avLNQ0BRin8dcM/c84F0LDnsYqFjat0+ZRE/GC DANvoIj9ORlVkIqiQWa/2Boen9S4GMSD/jHwryu0qzZ1Bu91C+gw4DVlBBQvJFO8WKla D1oMOc/2OBm/4+PsFW6bjHWN78WD4hkdIYv48EUaSasmso7j/tPhgefT/wlxC3SfjgxB WE6Q== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@cmpxchg-org.20150623.gappssmtp.com header.s=20150623 header.b="gHA/myvR"; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=cmpxchg.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id f18si5003543eja.587.2021.04.01.12.49.02; Thu, 01 Apr 2021 12:49:24 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@cmpxchg-org.20150623.gappssmtp.com header.s=20150623 header.b="gHA/myvR"; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=cmpxchg.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235232AbhDATsA (ORCPT + 99 others); Thu, 1 Apr 2021 15:48:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57730 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234089AbhDATr7 (ORCPT ); Thu, 1 Apr 2021 15:47:59 -0400 Received: from mail-qk1-x731.google.com (mail-qk1-x731.google.com [IPv6:2607:f8b0:4864:20::731]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BC50CC0613E6 for ; Thu, 1 Apr 2021 12:47:59 -0700 (PDT) Received: by mail-qk1-x731.google.com with SMTP id i9so3438108qka.2 for ; Thu, 01 Apr 2021 12:47:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cmpxchg-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=Qpz5/i5ZiJKb5n7InY8CiPZlk0x+Dq7b/uIx2Bj5OpE=; b=gHA/myvRTrd31/FpZ3kQwDv2jGlHY8liwkebl0Xrla8zjpNPXLQr261xsvUieysw+3 aiOG5eTaNxH2yEBUPqo5T8eKwc5eUs1IvRbCLoM8V0dKE8oFP9PCAhGSGvzl1ZOaHB5f 0fNY61RvGYD5clArYU0vrt82aYuH1xLDRO+yb0CxMDdtHX6QAOg8itU5lcLPFUHbBSDy AYfedNarmeh6T5cC3bIX5NYzGkaQZgPFNwV83zgrhs98VkrPW+mKGo4ykVLI1dCGnU1b fERVV5dKAkQOs2oIUoLvQPNcKXyr61FkWOcI4CXq6PdEkFTMfI/UGIXihJZCGOHgLo3h 1bvA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=Qpz5/i5ZiJKb5n7InY8CiPZlk0x+Dq7b/uIx2Bj5OpE=; b=EGWtzxx8htByjjQt1eLkCv1PUxb5NLmyqFhMoeIzh2vax8u3QkEn9kR07Fus4aIkUJ iRYssFcXwT5w07BKVgp/HnONP/JtllBRqA+pXPOkG9nkI2RRKeWESPITSC+LYi1WmmLU 1grAdTP2em4Z13xdRrxSR24b8Sp7C22QO0V9ZP54uIqSV0aj2KT3zp9IUzTZB8m9K84J 3qA8RuMtMZBOpA6SaH3buCsuxUQVrQ8mgZH/ujCWcRZu2RxyJoAcxugAQl3CiVVphFqL duAtU7rzqalW1qKTZfXYXt5EeP+RWh2/d26E0baSsF+rTst8chb0+QdslltRJRncdjMs 5l3A== X-Gm-Message-State: AOAM533rMAzVgOHTiN1DLnNlQRF+fqOoYW/sFEBPr/31IWFWPjfnAi4v IvU18l4jowp5s5ZP6gFqq3624A== X-Received: by 2002:a37:9c4a:: with SMTP id f71mr10025840qke.74.1617306479013; Thu, 01 Apr 2021 12:47:59 -0700 (PDT) Received: from localhost ([2620:10d:c091:480::1:9738]) by smtp.gmail.com with ESMTPSA id p186sm4887311qka.66.2021.04.01.12.47.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 01 Apr 2021 12:47:58 -0700 (PDT) Date: Thu, 1 Apr 2021 15:47:57 -0400 From: Johannes Weiner To: Peter Zijlstra Cc: Josh Hunt , Ingo Molnar , linux-kernel@vger.kernel.org Subject: Re: [PATCH] psi: allow unprivileged users with CAP_SYS_RESOURCE to write psi files Message-ID: References: <20210401033156.7262-1-johunt@akamai.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 01, 2021 at 08:47:33AM +0200, Peter Zijlstra wrote: > On Wed, Mar 31, 2021 at 11:31:56PM -0400, Josh Hunt wrote: > > Currently only root can write files under /proc/pressure. Relax this to > > allow tasks running as unprivileged users with CAP_SYS_RESOURCE to be > > able to write to these files. > > > > Signed-off-by: Josh Hunt > > I suppose that's ok, but lets also ask Johannes. The write creates a kthread that runs as SCHED_FIFO. For userspace threads this is reserved for CAP_SYS_NICE tasks, but it's a kernel thread and not arbitrary code, so I suppose CAP_SYS_RESOURCE is fine. Acked-by: Johannes Weiner