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 X-Spam-Level: X-Spam-Status: No, score=-8.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4D03FC433B4 for ; Thu, 1 Apr 2021 19:48:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 141476023C for ; Thu, 1 Apr 2021 19:48:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235352AbhDATsA (ORCPT ); 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-Google-Smtp-Source: ABdhPJyX+i7fJoUY5Xl4vvZeyhOgOYS40nQagciH0+td2piB+6uyxeb8b41v94ByGinn6A/r9Ujq7A== 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