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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by aws-us-west-2-korg-lkml-1.web.codeaurora.org (Postfix) with ESMTP id 16C9CC5CFF1 for ; Tue, 12 Jun 2018 22:54:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BAA1E20891 for ; Tue, 12 Jun 2018 22:54:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linaro.org header.i=@linaro.org header.b="J2f/0jNS" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BAA1E20891 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linaro.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935081AbeFLWyE (ORCPT ); Tue, 12 Jun 2018 18:54:04 -0400 Received: from mail-wr0-f196.google.com ([209.85.128.196]:39792 "EHLO mail-wr0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935033AbeFLWyA (ORCPT ); Tue, 12 Jun 2018 18:54:00 -0400 Received: by mail-wr0-f196.google.com with SMTP id w7-v6so685966wrn.6 for ; Tue, 12 Jun 2018 15:53:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=VlYvQP3073KxZfp6eQnnDLuq0RxOpbhqQpOKhO5xfW8=; b=J2f/0jNSrYiQu0mh+4FRbxXyuQf6VT2VD240ngR/c2V75MpQG+6Bnv+/CCxc7SHqMf zDRxg/qCzobzHsxLpR4qkQvSxmTyDtH33rV3X5CzswEwyAg9uDXS7c1KEkH2a4Bn/ETx MVeajMjFi70Kom2ukC3gVYfVXSLCufyHLk+tk= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=VlYvQP3073KxZfp6eQnnDLuq0RxOpbhqQpOKhO5xfW8=; b=a12f47ECUpE2k/5Cm3NsM1KXdDekVNqXB4UdNbIOHlEBLOBFpiMWeW6zUDkNdopctO C2eBHKUYyWZq23r6Unnf89Ii8F+CvoWxRxnEC+TM67CCRe3YM6dGyT2xI6cWsebc+SNX eSKxz+lWnEl83d8ESjSjZF1A38irjoYMMhZwJzyxTtHEamRwD4Ud0F05RmrkyvSBMOvL g2cUKnbwmI06u4NAPodnziKD5g8+uf/MuLq86nHLByZzsDVIrqBcw02lK2x1x14lvLkQ GsVlykY+1eH4yzhULYZqLqfcp2r9luX1ehRYU/dPG8uYIkQTcwsO9WrSPCJ74qMhfX2j vEpg== X-Gm-Message-State: APt69E2T125Uc40H0yV2mYqi+BKcViay8fHN+b/2grcuTlhHEdeqNSCJ z3vJhcdhSl4hNlSoA8Q6fimRog6O6YfUFns1yvcpvA== X-Google-Smtp-Source: ADUXVKK+ARPWYY2g9pSAyqp9akO1Wwag+al+Auvmu4h8EdDo77/e31m+D7ubFoGKdSWUT7MSXB0wh40nOPvqnc/p6z4= X-Received: by 2002:adf:ab96:: with SMTP id s22-v6mr2250946wrc.90.1528844038890; Tue, 12 Jun 2018 15:53:58 -0700 (PDT) MIME-Version: 1.0 Received: by 2002:a1c:8ac3:0:0:0:0:0 with HTTP; Tue, 12 Jun 2018 15:53:58 -0700 (PDT) In-Reply-To: References: From: John Stultz Date: Tue, 12 Jun 2018 15:53:58 -0700 Message-ID: Subject: Re: REGRESSION?: debugfs: inode: debugfs_create_dir uses mode permission from parent To: Kees Cook Cc: Laura Abbott , Thomas Richter , Greg Kroah-Hartman , lkml Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jun 12, 2018 at 3:52 PM, Kees Cook wrote: > On Tue, Jun 12, 2018 at 3:40 PM, John Stultz wrote: >> Hey all, >> I noticed recently that linus/master (plus patches) stopped booting >> to UI on HiKey960, and I bisected the issue down to: >> 92170b62f1c1 ("debugfs: inode: debugfs_create_dir uses mode permission >> from parent") >> >> On the HiKey960 board, we mount debugfs via: >> mount debugfs /sys/kernel/debug /sys/kernel/debug mode=755 >> >> But since the change, it seems most of the nodes in /sys/kernel/debug >> are: drwx------ >> >> Which ends up breaking the egl library, keeping it from loading. >> >> This seems to be the expected behavior of the patch, but I'm surprised >> the mode override is now ignored. It seems like the potential fix here >> would be to set the /sys/kernel/debug dir to 755 prior to mounting? Or >> is there some other advised solution? > > This change has already be reverted from other people reporting the > problem. Perhaps the root cause is the lack of propagation of the > mode= value? Ah! Thanks, sorry for not searching for the earlier discussion. thanks -john