From: Stephen Rothwell <hidden> Date: 2021-08-30 08:44:34
Hi all,
After merging the kspp tree, today's linux-next build (powerpc
allyesconfig) produced this warning:
drivers/gpu/drm/kmb/kmb_plane.c:135:20: warning: array subscript 3 is above array bounds of 'struct layer_status[1]' [-Warray-bounds]
135 | kmb->plane_status[plane_id].ctrl = LCD_CTRL_GL2_ENABLE;
| ~~~~~~~~~~~~~~~~~^~~~~~~~~~
In file included from drivers/gpu/drm/kmb/kmb_plane.c:17:
drivers/gpu/drm/kmb/kmb_drv.h:48:23: note: while referencing 'plane_status'
48 | struct layer_status plane_status[KMB_MAX_PLANES];
| ^~~~~~~~~~~~
drivers/gpu/drm/kmb/kmb_plane.c:132:20: warning: array subscript 2 is above array bounds of 'struct layer_status[1]' [-Warray-bounds]
132 | kmb->plane_status[plane_id].ctrl = LCD_CTRL_GL1_ENABLE;
| ~~~~~~~~~~~~~~~~~^~~~~~~~~~
In file included from drivers/gpu/drm/kmb/kmb_plane.c:17:
drivers/gpu/drm/kmb/kmb_drv.h:48:23: note: while referencing 'plane_status'
48 | struct layer_status plane_status[KMB_MAX_PLANES];
| ^~~~~~~~~~~~
drivers/gpu/drm/kmb/kmb_plane.c:129:20: warning: array subscript 1 is above array bounds of 'struct layer_status[1]' [-Warray-bounds]
129 | kmb->plane_status[plane_id].ctrl = LCD_CTRL_VL2_ENABLE;
| ~~~~~~~~~~~~~~~~~^~~~~~~~~~
In file included from drivers/gpu/drm/kmb/kmb_plane.c:17:
drivers/gpu/drm/kmb/kmb_drv.h:48:23: note: while referencing 'plane_status'
48 | struct layer_status plane_status[KMB_MAX_PLANES];
| ^~~~~~~~~~~~
Exposed by commit
656256c0d67c ("Makefile: Enable -Warray-bounds")
Introduced by commit
7f7b96a8a0a1 ("drm/kmb: Add support for KeemBay Display")
from v5.11-rc1.
--
Cheers,
Stephen Rothwell
On August 30, 2021 1:44:29 AM PDT, Stephen Rothwell [off-list ref] wrote:
Hi all,
After merging the kspp tree, today's linux-next build (powerpc
allyesconfig) produced this warning:
drivers/gpu/drm/kmb/kmb_plane.c:135:20: warning: array subscript 3 is above array bounds of 'struct layer_status[1]' [-Warray-bounds]
135 | kmb->plane_status[plane_id].ctrl = LCD_CTRL_GL2_ENABLE;
| ~~~~~~~~~~~~~~~~~^~~~~~~~~~
In file included from drivers/gpu/drm/kmb/kmb_plane.c:17:
drivers/gpu/drm/kmb/kmb_drv.h:48:23: note: while referencing 'plane_status'
48 | struct layer_status plane_status[KMB_MAX_PLANES];
| ^~~~~~~~~~~~
From: Stephen Rothwell <hidden> Date: 2021-08-31 00:49:37
Hi Kees,
On Mon, 30 Aug 2021 16:50:55 -0700 Kees Cook [off-list ref] wrote:
On August 30, 2021 1:44:29 AM PDT, Stephen Rothwell [off-list ref] wrote:
quoted
After merging the kspp tree, today's linux-next build (powerpc
allyesconfig) produced this warning:
drivers/gpu/drm/kmb/kmb_plane.c:135:20: warning: array subscript 3 is above array bounds of 'struct layer_status[1]' [-Warray-bounds]
135 | kmb->plane_status[plane_id].ctrl = LCD_CTRL_GL2_ENABLE;
| ~~~~~~~~~~~~~~~~~^~~~~~~~~~
In file included from drivers/gpu/drm/kmb/kmb_plane.c:17:
drivers/gpu/drm/kmb/kmb_drv.h:48:23: note: while referencing 'plane_status'
48 | struct layer_status plane_status[KMB_MAX_PLANES];
| ^~~~~~~~~~~~
On Mon, Sep 06, 2021 at 03:41:51PM +1000, Stephen Rothwell wrote:
Hi all,
On Mon, 30 Aug 2021 18:44:29 +1000 Stephen Rothwell [off-list ref] wrote:
quoted
After merging the kspp tree, today's linux-next build (powerpc
allyesconfig) produced this warning:
drivers/gpu/drm/kmb/kmb_plane.c:135:20: warning: array subscript 3 is above array bounds of 'struct layer_status[1]' [-Warray-bounds]
135 | kmb->plane_status[plane_id].ctrl = LCD_CTRL_GL2_ENABLE;
| ~~~~~~~~~~~~~~~~~^~~~~~~~~~
In file included from drivers/gpu/drm/kmb/kmb_plane.c:17:
drivers/gpu/drm/kmb/kmb_drv.h:48:23: note: while referencing 'plane_status'
48 | struct layer_status plane_status[KMB_MAX_PLANES];
| ^~~~~~~~~~~~
drivers/gpu/drm/kmb/kmb_plane.c:132:20: warning: array subscript 2 is above array bounds of 'struct layer_status[1]' [-Warray-bounds]
132 | kmb->plane_status[plane_id].ctrl = LCD_CTRL_GL1_ENABLE;
| ~~~~~~~~~~~~~~~~~^~~~~~~~~~
In file included from drivers/gpu/drm/kmb/kmb_plane.c:17:
drivers/gpu/drm/kmb/kmb_drv.h:48:23: note: while referencing 'plane_status'
48 | struct layer_status plane_status[KMB_MAX_PLANES];
| ^~~~~~~~~~~~
drivers/gpu/drm/kmb/kmb_plane.c:129:20: warning: array subscript 1 is above array bounds of 'struct layer_status[1]' [-Warray-bounds]
129 | kmb->plane_status[plane_id].ctrl = LCD_CTRL_VL2_ENABLE;
| ~~~~~~~~~~~~~~~~~^~~~~~~~~~
In file included from drivers/gpu/drm/kmb/kmb_plane.c:17:
drivers/gpu/drm/kmb/kmb_drv.h:48:23: note: while referencing 'plane_status'
48 | struct layer_status plane_status[KMB_MAX_PLANES];
| ^~~~~~~~~~~~
Exposed by commit
656256c0d67c ("Makefile: Enable -Warray-bounds")
Introduced by commit
7f7b96a8a0a1 ("drm/kmb: Add support for KeemBay Display")
from v5.11-rc1.
Due to Linus -Werror, these are now errors :-(
I have reverted commit 656256c0d67c for now.
I'm still surprised Linus added -Werror (it seems to go against years of
his earlier mandates on not breaking the build). Seems like
3fe617ccafd6 should be reverted instead. ;)
Linus, warnings are being reported (as above), are you sure -Werror is
the right way to go? (I can't believe I'm saying this, given my past
desire to make various hardening failures break the build -- you
convinced me to always warn instead, and it made good sense: a developer
still gets binary results as well as any new warnings...)
-Kees
--
Kees Cook
On Mon, Sep 6, 2021 at 10:06 AM Kees Cook [off-list ref] wrote:
quoted
Linus, warnings are being reported (as above)
New warnings are apparently at least partly reported, but also clearly
(a) old warnings are ignored, and (b) new warnings seem to be very
spottily fixed too.
Guenter reports "pass: 89 fail: 64" for his build setups.
So the fact that *I* require a clean build, and generally have two
reject a couple of build requests every merge window because of that
clearly doesn't mean that we actually have clean builds.
I've had that "no warnings" requirement for years. And that means that
*my* build has been clean for years.
I want *all* builds to be clean, or at least as far as possible.
You should be the last to complain. You are literally the drop that
broke the camel's back. I'm done being the last guard against build
warnings.
Linus