From patchwork Thu May 12 21:17:04 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nathan Chancellor X-Patchwork-Id: 12848145 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 74E34C433EF for ; Thu, 12 May 2022 21:17:25 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 40A2910F059; Thu, 12 May 2022 21:17:24 +0000 (UTC) Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by gabe.freedesktop.org (Postfix) with ESMTPS id F409210F059; Thu, 12 May 2022 21:17:22 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 16A5161EE3; Thu, 12 May 2022 21:17:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 868CDC385B8; Thu, 12 May 2022 21:17:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1652390241; bh=LqARVq2lcGKNOIxt7wFh53bt74j0X8rRusVOxvkYpqc=; h=From:To:Cc:Subject:Date:From; b=rZ3+EgEYyfYagLTq+TdC4pKBLiDez079XtAYlgTUYUFuMa0Ux2wykWoHakFcl66NP DMM1LrO2Go1ZGCa7NvfLFPw1ZYpSvu+jnRIwlnyL0VtGR4+ZciJKYE6w8DA0kKhZzP i/RzliIrkgPlOmyGRbUm3B8O/d+XccJEXp5059+ctKavd4qXTtyMJxGG/MRjQSCSHj +1BIlMiDFc4YvnrGGbcyFsKig6kZVxRxf5RiDeSxoS1tj/Ye9jf4MBVpGltSCHdpN6 mqIJBjcYU+gvxi0cNXDsYkzK64SkUtAOPO0leSOiYbA1pQEMH3NmxuQ3j7Ao1SDAv+ jGYAbhzxC8eDg== From: Nathan Chancellor To: Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , Tvrtko Ursulin Subject: [PATCH] drm/i915: Fix CFI violation with show_dynamic_id() Date: Thu, 12 May 2022 14:17:04 -0700 Message-Id: <20220512211704.3158759-1-nathan@kernel.org> X-Mailer: git-send-email 2.36.1 MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - 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, Nathan Chancellor , Sami Tolvanen Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" 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 Reviewed-by: Kees Cook Reviewed-by: Sami Tolvanen --- drivers/gpu/drm/i915/i915_perf.c | 4 ++-- drivers/gpu/drm/i915/i915_perf_types.h | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) base-commit: 7ecc3cc8a7b39f08eee9aea7b718187583342a70 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;