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 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 0F34DC433EF for ; Fri, 13 May 2022 10:08:56 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 71D8110E08A; Fri, 13 May 2022 10:08:56 +0000 (UTC) Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by gabe.freedesktop.org (Postfix) with ESMTPS id DF0AB10E08A; Fri, 13 May 2022 10:08:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1652436535; x=1683972535; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=5i3oSmoCYG0z99aFLyfO1/Lffb6G3ID6DMGfB1vnRWE=; b=Ow1b4MWRgrwVXXhQocaum0ZojppucjRj9cu1VVyKt9G0a80RncJamK3v t8Pncl64FHNdakg6afH+Lq28BtmxXYu00QKQ1JYMftGu6go7Bkv6IUv9u VcJ4bh3b1YGrcN1fhWMZ0/ostcnu8aUXEhPP11ImBzQ5npYHBvjNXRbgF rQB9/W2c8PhLRq7jvSP+j+kfo7hyd6LX8cqIrcAPj2nMp03qQs6xPRNsX jrA+yynIomLoKf+76imCFzk5lnSRotAWHdDfdQFawHFTA4otVTxgTGOtd wwKZdv/E1/8uqiAZ6vKOEjbsZPLflO9hbiC2RgsPOL5jcimwyFsffVyKG g==; X-IronPort-AV: E=McAfee;i="6400,9594,10345"; a="250170290" X-IronPort-AV: E=Sophos;i="5.91,221,1647327600"; d="scan'208";a="250170290" Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 May 2022 03:08:55 -0700 X-IronPort-AV: E=Sophos;i="5.91,221,1647327600"; d="scan'208";a="554167026" Received: from cpazx-mobl.ger.corp.intel.com (HELO [10.213.209.239]) ([10.213.209.239]) by orsmga002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 May 2022 03:08:52 -0700 Message-ID: Date: Fri, 13 May 2022 11:08:50 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.8.1 Content-Language: en-US To: Nathan Chancellor , Jani Nikula , Joonas Lahtinen , Rodrigo Vivi References: <20220512211704.3158759-1-nathan@kernel.org> From: Tvrtko Ursulin Organization: Intel Corporation UK Plc In-Reply-To: <20220512211704.3158759-1-nathan@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Intel-gfx] [PATCH] drm/i915: Fix CFI violation with show_dynamic_id() X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kees Cook , Tom Rix , intel-gfx@lists.freedesktop.org, llvm@lists.linux.dev, Nick Desaulniers , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, patches@lists.linux.dev, Sami Tolvanen Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On 12/05/2022 22:17, Nathan Chancellor wrote: > When an attribute group is created with sysfs_create_group(), the > ->sysfs_ops() callback is set to kobj_sysfs_ops, which sets the ->show() > callback to kobj_attr_show(). kobj_attr_show() uses container_of() to > get the ->show() callback from the attribute it was passed, meaning the > ->show() callback needs to be the same type as the ->show() callback in > 'struct kobj_attribute'. > > However, show_dynamic_id() has the type of the ->show() callback in > 'struct device_attribute', which causes a CFI violation when opening the > 'id' sysfs node under drm/card0/metrics. This happens to work because > the layout of 'struct kobj_attribute' and 'struct device_attribute' are > the same, so the container_of() cast happens to allow the ->show() > callback to still work. > > Change the type of show_dynamic_id() to match the ->show() callback in > 'struct kobj_attributes' and update the type of sysfs_metric_id to > match, which resolves the CFI violation. > > Fixes: f89823c21224 ("drm/i915/perf: Implement I915_PERF_ADD/REMOVE_CONFIG interface") > Signed-off-by: Nathan Chancellor Merged to drm-intel-gt-next, thanks for the fix and reviews! Regards, Tvrtko > --- > drivers/gpu/drm/i915/i915_perf.c | 4 ++-- > drivers/gpu/drm/i915/i915_perf_types.h | 2 +- > 2 files changed, 3 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c > index 0a9c3fcc09b1..1577ab6754db 100644 > --- a/drivers/gpu/drm/i915/i915_perf.c > +++ b/drivers/gpu/drm/i915/i915_perf.c > @@ -4050,8 +4050,8 @@ static struct i915_oa_reg *alloc_oa_regs(struct i915_perf *perf, > return ERR_PTR(err); > } > > -static ssize_t show_dynamic_id(struct device *dev, > - struct device_attribute *attr, > +static ssize_t show_dynamic_id(struct kobject *kobj, > + struct kobj_attribute *attr, > char *buf) > { > struct i915_oa_config *oa_config = > diff --git a/drivers/gpu/drm/i915/i915_perf_types.h b/drivers/gpu/drm/i915/i915_perf_types.h > index 473a3c0544bb..05cb9a335a97 100644 > --- a/drivers/gpu/drm/i915/i915_perf_types.h > +++ b/drivers/gpu/drm/i915/i915_perf_types.h > @@ -55,7 +55,7 @@ struct i915_oa_config { > > struct attribute_group sysfs_metric; > struct attribute *attrs[2]; > - struct device_attribute sysfs_metric_id; > + struct kobj_attribute sysfs_metric_id; > > struct kref ref; > struct rcu_head rcu; > > base-commit: 7ecc3cc8a7b39f08eee9aea7b718187583342a70