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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 4F5A1C2D0E4 for ; Sat, 21 Nov 2020 03:38:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 000CE22269 for ; Sat, 21 Nov 2020 03:38:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="oIA/PxpW" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726596AbgKUDiO (ORCPT ); Fri, 20 Nov 2020 22:38:14 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41780 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726189AbgKUDiO (ORCPT ); Fri, 20 Nov 2020 22:38:14 -0500 Received: from mail-ot1-x341.google.com (mail-ot1-x341.google.com [IPv6:2607:f8b0:4864:20::341]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1085DC061A48 for ; Fri, 20 Nov 2020 19:38:13 -0800 (PST) Received: by mail-ot1-x341.google.com with SMTP id o3so10719785ota.8 for ; Fri, 20 Nov 2020 19:38:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=l7hc1HlYFf6JH4NXyv3Pj9whwOskfPzzd3TWVpR6m6E=; b=oIA/PxpWOYoEYGdA6XqOqU3xN7WxOm2IqrNVjN+N6UKHO6+sdlGUExX4sSfiuzL4m7 GYMxGcGoGDbiRXYuj/0DC9Zl1kv0AE9csq6LEkP8YmV8Mp2AeS0JZsk33ZvwpIGqKAj+ kGXjviC82qTZ+E1VNf9AHsPXKSU6gxKD/O2AyDkmkRQ3UaaVHTXPxcMgbVXpoALhYoWj YStEYZVKX/Gjf3cEcACqLgQhiIJ0DDdIDa+UhvaNtQd3yx+M9BvSk1l4bNPB2blU/Y7x +YkBu8oabC5xUNXlAd7rMBPICIrT0TDDufn8BEyQ/XCTTvIKmKeMXslCinss7gjFyMNf XkrQ== 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=l7hc1HlYFf6JH4NXyv3Pj9whwOskfPzzd3TWVpR6m6E=; b=Imd42j23w+wd+1d9frWDIIr79VIpkKqcw5jf+75+MI7kuSii+hQ+woXKosa+o0beds UCcgBT5g2aQrK6PXhBwKJOYFK4b+gD99T5YQHF3Xux881tuXkFfzcDkfDSc1lkh3JZea Ha7feW5ThMoSuUddsfEWtrsqvWIGrki7gIUeDAkLPhLP6UZ9jnW40QMlGCU6hyrdG4Ws Wk/BMtEOXOp/q/gUaOXUOOHTIpPwy4EVHIl5xrF7aRFJg7oqrw4ERx06NhyHG75qJkwv RG34Mty9w106sf9rwuFxTlywLuKX3kN48IPBW2QL79qVZKS+LXONnLAXLZyHBt/W31us 797A== X-Gm-Message-State: AOAM531CkCiuBBN5YABEiRRuTE0vJE3YbG1Wr1+6hy2vlFKmhmdQCLwQ 0EjPXs6CYbkl6QYo0Is4c8+72A== X-Google-Smtp-Source: ABdhPJweblholREjeMlmQlXN5V2dtCpEbRmwV75t5defnTB2dZKHyQvFrcBCL/yNR3TTrIzFEl1T4w== X-Received: by 2002:a9d:7c98:: with SMTP id q24mr14666681otn.147.1605929893199; Fri, 20 Nov 2020 19:38:13 -0800 (PST) Received: from builder.lan (104-57-184-186.lightspeed.austtx.sbcglobal.net. [104.57.184.186]) by smtp.gmail.com with ESMTPSA id x9sm2402926otk.9.2020.11.20.19.38.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 20 Nov 2020 19:38:12 -0800 (PST) Date: Fri, 20 Nov 2020 21:38:10 -0600 From: Bjorn Andersson To: Suman Anna Cc: Mathieu Poirier , Arnaud Pouliquen , Loic Pallardy , Grzegorz Jaszczyk , Tony Lindgren , linux-remoteproc@vger.kernel.org, linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 2/3] remoteproc: Introduce deny_sysfs_ops flag Message-ID: <20201121033810.GG9177@builder.lan> References: <20201121030156.22857-1-s-anna@ti.com> <20201121030156.22857-3-s-anna@ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201121030156.22857-3-s-anna@ti.com> Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org On Fri 20 Nov 21:01 CST 2020, Suman Anna wrote: > The remoteproc framework provides sysfs interfaces for changing > the firmware name and for starting/stopping a remote processor > through the sysfs files 'state' and 'firmware'. The 'recovery' > sysfs file can also be used similarly to control the error recovery > state machine of a remoteproc. These interfaces are currently > allowed irrespective of how the remoteprocs were booted (like > remoteproc self auto-boot, remoteproc client-driven boot etc). > These interfaces can adversely affect a remoteproc and its clients > especially when a remoteproc is being controlled by a remoteproc > client driver(s). Also, not all remoteproc drivers may want to > support the sysfs interfaces by default. > > Add support to deny the sysfs state/firmware/recovery change by > introducing a state flag 'deny_sysfs_ops' that the individual > remoteproc drivers can set based on their usage needs. The default > behavior is to allow the sysfs operations as before. > This makes sense, but can't we implement attribute_group->is_visible to simply hide these entries from userspace instead of leaving them "broken"? Regards, Bjorn > Signed-off-by: Suman Anna > --- > v2: revised to account for the 'recovery' sysfs file as well, patch > description updated accordingly > v1: https://patchwork.kernel.org/project/linux-remoteproc/patch/20180915003725.17549-5-s-anna@ti.com/ > > drivers/remoteproc/remoteproc_sysfs.c | 12 ++++++++++++ > include/linux/remoteproc.h | 2 ++ > 2 files changed, 14 insertions(+) > > diff --git a/drivers/remoteproc/remoteproc_sysfs.c b/drivers/remoteproc/remoteproc_sysfs.c > index bd2950a246c9..3fd18a71c188 100644 > --- a/drivers/remoteproc/remoteproc_sysfs.c > +++ b/drivers/remoteproc/remoteproc_sysfs.c > @@ -49,6 +49,10 @@ static ssize_t recovery_store(struct device *dev, > { > struct rproc *rproc = to_rproc(dev); > > + /* restrict sysfs operations if not allowed by remoteproc drivers */ > + if (rproc->deny_sysfs_ops) > + return -EPERM; > + > if (sysfs_streq(buf, "enabled")) { > /* change the flag and begin the recovery process if needed */ > rproc->recovery_disabled = false; > @@ -158,6 +162,10 @@ static ssize_t firmware_store(struct device *dev, > char *p; > int err, len = count; > > + /* restrict sysfs operations if not allowed by remoteproc drivers */ > + if (rproc->deny_sysfs_ops) > + return -EPERM; > + > err = mutex_lock_interruptible(&rproc->lock); > if (err) { > dev_err(dev, "can't lock rproc %s: %d\n", rproc->name, err); > @@ -225,6 +233,10 @@ static ssize_t state_store(struct device *dev, > struct rproc *rproc = to_rproc(dev); > int ret = 0; > > + /* restrict sysfs operations if not allowed by remoteproc drivers */ > + if (rproc->deny_sysfs_ops) > + return -EPERM; > + > if (sysfs_streq(buf, "start")) { > if (rproc->state == RPROC_RUNNING) > return -EBUSY; > diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h > index 3fa3ba6498e8..dbc3767f7d0e 100644 > --- a/include/linux/remoteproc.h > +++ b/include/linux/remoteproc.h > @@ -508,6 +508,7 @@ struct rproc_dump_segment { > * @has_iommu: flag to indicate if remote processor is behind an MMU > * @auto_boot: flag to indicate if remote processor should be auto-started > * @autonomous: true if an external entity has booted the remote processor > + * @deny_sysfs_ops: flag to not permit sysfs operations on state, firmware and recovery > * @dump_segments: list of segments in the firmware > * @nb_vdev: number of vdev currently handled by rproc > * @char_dev: character device of the rproc > @@ -545,6 +546,7 @@ struct rproc { > bool has_iommu; > bool auto_boot; > bool autonomous; > + bool deny_sysfs_ops; > struct list_head dump_segments; > int nb_vdev; > u8 elf_class; > -- > 2.28.0 >