linux-next: build warning after merge of the kspp tree

linux-next: build warning after merge of the kspp tree

[Stephen Rothwell]

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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

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Re: linux-next: build warning after merge of the kspp tree

[Kees Cook]

On August 30, 2021 1:44:29 AM PDT, Stephen Rothwell <sfr@canb.auug.org.au> 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];
>      |                       ^~~~~~~~~~~~

Hi!

Ah yes, thanks for the report. I encountered this too, and have been told the warning will go away soon:
https://lore.kernel.org/lkml/BY5PR11MB4182ABD607EB99C1F68777928CC69@BY5PR11MB4182.namprd11.prod.outlook.com/

-Kees

Re: linux-next: build warning after merge of the kspp tree

[Stephen Rothwell]

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Hi Kees,

On Mon, 30 Aug 2021 16:50:55 -0700 Kees Cook <keescook@chromium.org> wrote:
>
> On August 30, 2021 1:44:29 AM PDT, Stephen Rothwell <sfr@canb.auug.org.au> wrote:
> >
> >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];
> >      |                       ^~~~~~~~~~~~  
> 
> Ah yes, thanks for the report. I encountered this too, and have been told the warning will go away soon:
> https://lore.kernel.org/lkml/BY5PR11MB4182ABD607EB99C1F68777928CC69@BY5PR11MB4182.namprd11.prod.outlook.com/

ok, thanks

-- 
Cheers,
Stephen Rothwell

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Re: linux-next: build warning after merge of the kspp tree

[Stephen Rothwell]

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Hi all,

On Mon, 30 Aug 2021 18:44:29 +1000 Stephen Rothwell <sfr@canb.auug.org.au> wrote:
>
> 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.
-- 
Cheers,
Stephen Rothwell

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Re: linux-next: build warning after merge of the kspp tree

[Kees Cook]

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 <sfr@canb.auug.org.au> wrote:
> >
> > 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

Re: linux-next: build warning after merge of the kspp tree

[Linus Torvalds]

On Mon, Sep 6, 2021 at 10:06 AM Kees Cook <keescook@chromium.org> wrote:
>>
> 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

linux-next: build warning after merge of the kspp tree

[Stephen Rothwell]

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Hi all,

After merging the kspp tree, today's linux-next build (htmldocs) produced
this warning:

include/linux/string.h:142: warning: Function parameter or struct member 'dst' not described in 'strscpy_pad'
include/linux/string.h:142: warning: Excess function parameter 'dest' description in 'strscpy_pad'
include/linux/string.h:142: warning: Excess function parameter 'count' description in 'strscpy_pad'

Introduced by commit

  0bf7961afff1 ("string: Allow 2-argument strscpy_pad()")

-- 
Cheers,
Stephen Rothwell

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Re: linux-next: build warning after merge of the kspp tree

[Kees Cook]

On Thu, Feb 08, 2024 at 02:48:42PM +1100, Stephen Rothwell wrote:
> Hi all,
> 
> After merging the kspp tree, today's linux-next build (htmldocs) produced
> this warning:
> 
> include/linux/string.h:142: warning: Function parameter or struct member 'dst' not described in 'strscpy_pad'
> include/linux/string.h:142: warning: Excess function parameter 'dest' description in 'strscpy_pad'
> include/linux/string.h:142: warning: Excess function parameter 'count' description in 'strscpy_pad'
> 
> Introduced by commit
> 
>   0bf7961afff1 ("string: Allow 2-argument strscpy_pad()")

Thanks! This is fixed now.

-- 
Kees Cook

linux-next: build warning after merge of the kspp tree

[Stephen Rothwell]

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Hi all,

After merging the kspp tree, today's linux-next build (arm
multi_v7_defconfig) produced this warning:

arch/arm/boot/compressed/misc.c:157:6: warning: no previous prototype for '__fortify_panic' [-Wmissing-prototypes]
  157 | void __fortify_panic(const u8 reason, size_t avail, size_t size)
      |      ^~~~~~~~~~~~~~~

Introduced by commit

  0f4459080884 ("fortify: Split reporting and avoid passing string pointer")

-- 
Cheers,
Stephen Rothwell

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linux-next: build warning after merge of the kspp tree

[Stephen Rothwell]

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Hi all,

After merging the kspp tree, today's linux-next build (htmldocs) produced
this warning:

include/linux/overflow.h:408: warning: Excess function parameter 'initializer...' description in '_DEFINE_FLEX'

Introduced by commit

  014dc22af922 ("overflow: Change DEFINE_FLEX to take __counted_by member")

-- 
Cheers,
Stephen Rothwell

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Re: linux-next: build warning after merge of the kspp tree

[Kees Cook]

On Thu, Mar 07, 2024 at 05:16:03PM +1100, Stephen Rothwell wrote:
> Hi all,
> 
> After merging the kspp tree, today's linux-next build (htmldocs) produced
> this warning:
> 
> include/linux/overflow.h:408: warning: Excess function parameter 'initializer...' description in '_DEFINE_FLEX'
> 
> Introduced by commit
> 
>   014dc22af922 ("overflow: Change DEFINE_FLEX to take __counted_by member")

Thanks! I've fixed this now. (Weird that kern-doc will take "..." as an
argument name, but "foo..." becomes "foo" not "foo...", but okay.)

-- 
Kees Cook