From: Arnd Bergmann <arnd@kernel•org>
To: linux-kernel@vger•kernel.org, Martin Sebor <msebor@gcc•gnu.org>,
Jani Nikula <jani.nikula@linux•intel.com>,
Joonas Lahtinen <joonas.lahtinen@linux•intel.com>,
Rodrigo Vivi <rodrigo.vivi@intel•com>,
David Airlie <airlied@linux•ie>, Daniel Vetter <daniel@ffwll•ch>
Cc: "Arnd Bergmann" <arnd@arndb•de>,
x86@kernel•org, "Ning Sun" <ning.sun@intel•com>,
"Kalle Valo" <kvalo@codeaurora•org>,
"Simon Kelley" <simon@thekelleys•org.uk>,
"James Smart" <james.smart@broadcom•com>,
"James E.J. Bottomley" <jejb@linux•ibm.com>,
"Anders Larsen" <al@alarsen•net>, "Tejun Heo" <tj@kernel•org>,
"Serge Hallyn" <serge@hallyn•com>,
"Imre Deak" <imre.deak@intel•com>,
linux-arm-kernel@lists•infradead.org,
tboot-devel@lists•sourceforge.net,
intel-gfx@lists•freedesktop.org, dri-devel@lists•freedesktop.org,
ath11k@lists•infradead.org, linux-wireless@vger•kernel.org,
netdev@vger•kernel.org, linux-scsi@vger•kernel.org,
cgroups@vger•kernel.org, linux-security-module@vger•kernel.org,
"Chris Wilson" <chris@chris-wilson•co.uk>,
"José Roberto de Souza" <jose.souza@intel•com>,
"Ville Syrjälä" <ville.syrjala@linux•intel.com>,
"Matt Roper" <matthew.d.roper@intel•com>,
"Aditya Swarup" <aditya.swarup@intel•com>
Subject: [PATCH 10/11] drm/i915: avoid stringop-overread warning on pri_latency
Date: Mon, 22 Mar 2021 17:02:48 +0100 [thread overview]
Message-ID: <20210322160253.4032422-11-arnd@kernel.org> (raw)
In-Reply-To: <20210322160253.4032422-1-arnd@kernel.org>
From: Arnd Bergmann <arnd@arndb•de>
gcc-11 warns about what appears to be an out-of-range array access:
In function ‘snb_wm_latency_quirk’,
inlined from ‘ilk_setup_wm_latency’ at drivers/gpu/drm/i915/intel_pm.c:3108:3:
drivers/gpu/drm/i915/intel_pm.c:3057:9: error: ‘intel_print_wm_latency’ reading 16 bytes from a region of size 10 [-Werror=stringop-overread]
3057 | intel_print_wm_latency(dev_priv, "Primary", dev_priv->wm.pri_latency);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/i915/intel_pm.c: In function ‘ilk_setup_wm_latency’:
drivers/gpu/drm/i915/intel_pm.c:3057:9: note: referencing argument 3 of type ‘const u16 *’ {aka ‘const short unsigned int *’}
drivers/gpu/drm/i915/intel_pm.c:2994:13: note: in a call to function ‘intel_print_wm_latency’
2994 | static void intel_print_wm_latency(struct drm_i915_private *dev_priv,
| ^~~~~~~~~~~~~~~~~~~~~~
My guess is that this code is actually safe because the size of the
array depends on the hardware generation, and the function checks for
that, but at the same time I would not expect the compiler to work it
out correctly, and the code seems a little fragile with regards to
future changes. Simply increasing the size of the array should help.
Signed-off-by: Arnd Bergmann <arnd@arndb•de>
---
drivers/gpu/drm/i915/i915_drv.h | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 26d69d06aa6d..3567602e0a35 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1095,11 +1095,11 @@ struct drm_i915_private {
* in 0.5us units for WM1+.
*/
/* primary */
- u16 pri_latency[5];
+ u16 pri_latency[8];
/* sprite */
- u16 spr_latency[5];
+ u16 spr_latency[8];
/* cursor */
- u16 cur_latency[5];
+ u16 cur_latency[8];
/*
* Raw watermark memory latency values
* for SKL for all 8 levels
--
2.29.2
next prev parent reply other threads:[~2021-03-22 16:07 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-22 16:02 [PATCH 00/11] treewide: address gcc-11 -Wstringop-overread warnings Arnd Bergmann
2021-03-22 16:02 ` [PATCH 01/11] x86: compressed: avoid gcc-11 -Wstringop-overread warning Arnd Bergmann
2021-03-22 16:02 ` [PATCH 02/11] x86: tboot: avoid Wstringop-overread-warning Arnd Bergmann
2021-03-22 20:29 ` Ingo Molnar
2021-03-22 21:39 ` Arnd Bergmann
2021-03-22 22:07 ` Martin Sebor
2021-03-22 22:49 ` Arnd Bergmann
2021-03-22 23:13 ` Ingo Molnar
2021-03-24 9:11 ` David Laight
2021-03-24 10:39 ` David Laight
2021-03-22 16:02 ` [PATCH 03/11] security: commoncap: fix -Wstringop-overread warning Arnd Bergmann
2021-03-22 16:31 ` Christian Brauner
2021-03-24 20:50 ` James Morris
2021-03-22 16:02 ` [PATCH 04/11] ath11: Wstringop-overread warning Arnd Bergmann
2021-09-28 9:04 ` Kalle Valo
2021-03-22 16:02 ` [PATCH 05/11] qnx: avoid -Wstringop-overread warning Arnd Bergmann
2021-03-22 16:02 ` [PATCH 06/11] cgroup: fix -Wzero-length-bounds warnings Arnd Bergmann
2021-03-30 8:41 ` Michal Koutný
2021-03-30 9:00 ` Arnd Bergmann
2021-03-30 14:44 ` Michal Koutný
2021-03-22 16:02 ` [PATCH 07/11] ARM: sharpsl_param: work around -Wstringop-overread warning Arnd Bergmann
2021-03-22 16:02 ` [PATCH 08/11] atmel: avoid gcc -Wstringop-overflow warning Arnd Bergmann
2021-03-22 16:02 ` [PATCH 09/11] scsi: lpfc: fix gcc -Wstringop-overread warning Arnd Bergmann
2021-03-22 16:02 ` Arnd Bergmann [this message]
2021-03-24 15:30 ` [PATCH 10/11] drm/i915: avoid stringop-overread warning on pri_latency Jani Nikula
2021-03-24 17:22 ` Ville Syrjälä
2021-03-22 16:02 ` [PATCH 11/11] [RFC] drm/i915/dp: fix array overflow warning Arnd Bergmann
2021-03-25 8:05 ` Jani Nikula
2021-03-25 9:53 ` Arnd Bergmann
2021-03-25 14:49 ` Martin Sebor
2021-03-30 10:56 ` Hans de Goede
2021-04-06 4:53 ` [PATCH 00/11] treewide: address gcc-11 -Wstringop-overread warnings Martin K. Petersen
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