From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Engestrom Date: Thu, 13 Oct 2016 09:07:22 +0000 Subject: Re: [patch] drm/i915: fix a read size argument Message-Id: <20161013090722.GI1743@imgtec.com> List-Id: References: <20161013085508.GJ16198@mwanda> In-Reply-To: <20161013085508.GJ16198@mwanda> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Dan Carpenter Cc: intel-gfx@lists.freedesktop.org, kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Daniel Vetter On Thu, Oct 13, 2016 at 11:55:08AM +0300, Dan Carpenter wrote: > We want to read 3 bytes here, but because the parenthesis are in the > wrong place we instead read: > > sizeof(intel_dp->edp_dpcd) = sizeof(intel_dp->edp_dpcd) > > which is one byte. > > Fixes: fe5a66f91c88 ("drm/i915: Read PSR caps/intermediate freqs/etc. only once on eDP") > Signed-off-by: Dan Carpenter Good catch! What tool did you use to find it, or did you find it by inspection? Reviewed-by: Eric Engestrom (btw, there's a missing `---` here, between the commit msg and the diff) > > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c > index 14a3cf0..ee8aa95 100644 > --- a/drivers/gpu/drm/i915/intel_dp.c > +++ b/drivers/gpu/drm/i915/intel_dp.c > @@ -3551,8 +3551,8 @@ intel_edp_init_dpcd(struct intel_dp *intel_dp) > /* Read the eDP Display control capabilities registers */ > if ((intel_dp->dpcd[DP_EDP_CONFIGURATION_CAP] & DP_DPCD_DISPLAY_CONTROL_CAPABLE) && > drm_dp_dpcd_read(&intel_dp->aux, DP_EDP_DPCD_REV, > - intel_dp->edp_dpcd, sizeof(intel_dp->edp_dpcd) = > - sizeof(intel_dp->edp_dpcd))) > + intel_dp->edp_dpcd, sizeof(intel_dp->edp_dpcd)) = > + sizeof(intel_dp->edp_dpcd)) > DRM_DEBUG_KMS("EDP DPCD : %*ph\n", (int) sizeof(intel_dp->edp_dpcd), > intel_dp->edp_dpcd); From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Engestrom Subject: Re: [patch] drm/i915: fix a read size argument Date: Thu, 13 Oct 2016 10:07:22 +0100 Message-ID: <20161013090722.GI1743@imgtec.com> References: <20161013085508.GJ16198@mwanda> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Received: from mailapp01.imgtec.com (mailapp02.imgtec.com [217.156.133.132]) by gabe.freedesktop.org (Postfix) with ESMTP id ADFB66E9D0 for ; Thu, 13 Oct 2016 09:07:24 +0000 (UTC) Content-Disposition: inline In-Reply-To: <20161013085508.GJ16198@mwanda> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Dan Carpenter Cc: intel-gfx@lists.freedesktop.org, kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Daniel Vetter List-Id: dri-devel@lists.freedesktop.org T24gVGh1LCBPY3QgMTMsIDIwMTYgYXQgMTE6NTU6MDhBTSArMDMwMCwgRGFuIENhcnBlbnRlciB3 cm90ZToKPiBXZSB3YW50IHRvIHJlYWQgMyBieXRlcyBoZXJlLCBidXQgYmVjYXVzZSB0aGUgcGFy ZW50aGVzaXMgYXJlIGluIHRoZQo+IHdyb25nIHBsYWNlIHdlIGluc3RlYWQgcmVhZDoKPiAKPiAJ c2l6ZW9mKGludGVsX2RwLT5lZHBfZHBjZCkgPT0gc2l6ZW9mKGludGVsX2RwLT5lZHBfZHBjZCkK PiAKPiB3aGljaCBpcyBvbmUgYnl0ZS4KPiAKPiBGaXhlczogZmU1YTY2ZjkxYzg4ICgiZHJtL2k5 MTU6IFJlYWQgUFNSIGNhcHMvaW50ZXJtZWRpYXRlIGZyZXFzL2V0Yy4gb25seSBvbmNlIG9uIGVE UCIpCj4gU2lnbmVkLW9mZi1ieTogRGFuIENhcnBlbnRlciA8ZGFuLmNhcnBlbnRlckBvcmFjbGUu Y29tPgoKR29vZCBjYXRjaCEgIFdoYXQgdG9vbCBkaWQgeW91IHVzZSB0byBmaW5kIGl0LCBvciBk aWQgeW91IGZpbmQgaXQgYnkKaW5zcGVjdGlvbj8KUmV2aWV3ZWQtYnk6IEVyaWMgRW5nZXN0cm9t IDxlcmljLmVuZ2VzdHJvbUBpbWd0ZWMuY29tPgoKKGJ0dywgdGhlcmUncyBhIG1pc3NpbmcgYC0t LWAgaGVyZSwgYmV0d2VlbiB0aGUgY29tbWl0IG1zZyBhbmQgdGhlIGRpZmYpCgo+IAo+IGRpZmYg LS1naXQgYS9kcml2ZXJzL2dwdS9kcm0vaTkxNS9pbnRlbF9kcC5jIGIvZHJpdmVycy9ncHUvZHJt L2k5MTUvaW50ZWxfZHAuYwo+IGluZGV4IDE0YTNjZjAuLmVlOGFhOTUgMTAwNjQ0Cj4gLS0tIGEv ZHJpdmVycy9ncHUvZHJtL2k5MTUvaW50ZWxfZHAuYwo+ICsrKyBiL2RyaXZlcnMvZ3B1L2RybS9p OTE1L2ludGVsX2RwLmMKPiBAQCAtMzU1MSw4ICszNTUxLDggQEAgaW50ZWxfZWRwX2luaXRfZHBj ZChzdHJ1Y3QgaW50ZWxfZHAgKmludGVsX2RwKQo+ICAJLyogUmVhZCB0aGUgZURQIERpc3BsYXkg Y29udHJvbCBjYXBhYmlsaXRpZXMgcmVnaXN0ZXJzICovCj4gIAlpZiAoKGludGVsX2RwLT5kcGNk W0RQX0VEUF9DT05GSUdVUkFUSU9OX0NBUF0gJiBEUF9EUENEX0RJU1BMQVlfQ09OVFJPTF9DQVBB QkxFKSAmJgo+ICAJICAgIGRybV9kcF9kcGNkX3JlYWQoJmludGVsX2RwLT5hdXgsIERQX0VEUF9E UENEX1JFViwKPiAtCQkJICAgICBpbnRlbF9kcC0+ZWRwX2RwY2QsIHNpemVvZihpbnRlbF9kcC0+ ZWRwX2RwY2QpID09Cj4gLQkJCSAgICAgc2l6ZW9mKGludGVsX2RwLT5lZHBfZHBjZCkpKQo+ICsJ CQkgICAgIGludGVsX2RwLT5lZHBfZHBjZCwgc2l6ZW9mKGludGVsX2RwLT5lZHBfZHBjZCkpID09 Cj4gKwkJCSAgICAgc2l6ZW9mKGludGVsX2RwLT5lZHBfZHBjZCkpCj4gIAkJRFJNX0RFQlVHX0tN UygiRURQIERQQ0QgOiAlKnBoXG4iLCAoaW50KSBzaXplb2YoaW50ZWxfZHAtPmVkcF9kcGNkKSwK PiAgCQkJICAgICAgaW50ZWxfZHAtPmVkcF9kcGNkKTsKX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX18KZHJpLWRldmVsIG1haWxpbmcgbGlzdApkcmktZGV2ZWxA bGlzdHMuZnJlZWRlc2t0b3Aub3JnCmh0dHBzOi8vbGlzdHMuZnJlZWRlc2t0b3Aub3JnL21haWxt YW4vbGlzdGluZm8vZHJpLWRldmVsCg== From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753124AbcJMJHu (ORCPT ); Thu, 13 Oct 2016 05:07:50 -0400 Received: from mailapp02.imgtec.com ([217.156.133.132]:24244 "EHLO mailapp01.imgtec.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752554AbcJMJHl (ORCPT ); Thu, 13 Oct 2016 05:07:41 -0400 Date: Thu, 13 Oct 2016 10:07:22 +0100 From: Eric Engestrom To: Dan Carpenter CC: Daniel Vetter , Ville =?utf-8?B?U3lyasOkbMOk?= , , , , Subject: Re: [patch] drm/i915: fix a read size argument Message-ID: <20161013090722.GI1743@imgtec.com> References: <20161013085508.GJ16198@mwanda> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Disposition: inline In-Reply-To: <20161013085508.GJ16198@mwanda> User-Agent: Mutt/1.7.1 (2016-10-04) X-Originating-IP: [10.60.4.28] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 13, 2016 at 11:55:08AM +0300, Dan Carpenter wrote: > We want to read 3 bytes here, but because the parenthesis are in the > wrong place we instead read: > > sizeof(intel_dp->edp_dpcd) == sizeof(intel_dp->edp_dpcd) > > which is one byte. > > Fixes: fe5a66f91c88 ("drm/i915: Read PSR caps/intermediate freqs/etc. only once on eDP") > Signed-off-by: Dan Carpenter Good catch! What tool did you use to find it, or did you find it by inspection? Reviewed-by: Eric Engestrom (btw, there's a missing `---` here, between the commit msg and the diff) > > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c > index 14a3cf0..ee8aa95 100644 > --- a/drivers/gpu/drm/i915/intel_dp.c > +++ b/drivers/gpu/drm/i915/intel_dp.c > @@ -3551,8 +3551,8 @@ intel_edp_init_dpcd(struct intel_dp *intel_dp) > /* Read the eDP Display control capabilities registers */ > if ((intel_dp->dpcd[DP_EDP_CONFIGURATION_CAP] & DP_DPCD_DISPLAY_CONTROL_CAPABLE) && > drm_dp_dpcd_read(&intel_dp->aux, DP_EDP_DPCD_REV, > - intel_dp->edp_dpcd, sizeof(intel_dp->edp_dpcd) == > - sizeof(intel_dp->edp_dpcd))) > + intel_dp->edp_dpcd, sizeof(intel_dp->edp_dpcd)) == > + sizeof(intel_dp->edp_dpcd)) > DRM_DEBUG_KMS("EDP DPCD : %*ph\n", (int) sizeof(intel_dp->edp_dpcd), > intel_dp->edp_dpcd);