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

[Stephen Rothwell]

Hi all,

On Mon, 16 May 2022 17:57:57 +1000 Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> wrote:
> 
> After merging the bluetooth tree, today's linux-next build (arm
> multi_v7_defconfig) produced this warning:
> 
> In file included from include/linux/cpumask.h:12,
>                  from include/linux/mm_types_task.h:14,
>                  from include/linux/mm_types.h:5,
>                  from include/linux/buildid.h:5,
>                  from include/linux/module.h:14,
>                  from net/bluetooth/mgmt.c:27:
> In function 'bitmap_copy',
>     inlined from 'bitmap_copy_clear_tail' at include/linux/bitmap.h:270:2,
>     inlined from 'bitmap_from_u64' at include/linux/bitmap.h:622:2,
>     inlined from 'set_device_flags' at net/bluetooth/mgmt.c:4534:4:
> include/linux/bitmap.h:261:9: warning: 'memcpy' forming offset [4, 7] is out of the bounds [0, 4] of object 'flags' with type 'long unsigned int[1]' [-Warray-bounds]
>   261 |         memcpy(dst, src, len);
>       |         ^~~~~~~~~~~~~~~~~~~~~
> In file included from include/linux/kasan-checks.h:5,
>                  from include/asm-generic/rwonce.h:26,
>                  from ./arch/arm/include/generated/asm/rwonce.h:1,
>                  from include/linux/compiler.h:248,
>                  from include/linux/build_bug.h:5,
>                  from include/linux/container_of.h:5,
>                  from include/linux/list.h:5,
>                  from include/linux/module.h:12,
>                  from net/bluetooth/mgmt.c:27:
> net/bluetooth/mgmt.c: In function 'set_device_flags':
> net/bluetooth/mgmt.c:4532:40: note: 'flags' declared here
>  4532 |                         DECLARE_BITMAP(flags, __HCI_CONN_NUM_FLAGS);
>       |                                        ^~~~~
> include/linux/types.h:11:23: note: in definition of macro 'DECLARE_BITMAP'
>    11 |         unsigned long name[BITS_TO_LONGS(bits)]
>       |                       ^~~~
> 
> Introduced by commit
> 
>   a9a347655d22 ("Bluetooth: MGMT: Add conditions for setting HCI_CONN_FLAG_REMOTE_WAKEUP")
> 
> Bitmaps consist of unsigned longs (in this case 32 bits) ...
> 
> (This warning only happens due to chnges in the bitmap tree.)

I still got this warning yesterday ...

-- 
Cheers,
Stephen Rothwell

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