Re: mainline build failure due to 332f1795ca20 ("Bluetooth: L2CAP: Fix l2cap_global_chan_by_psm regression")

[Paul Menzel <pmenzel@molgen.mpg.de>]

Dear Sudip,


Am 12.08.22 um 13:25 schrieb Sudip Mukherjee (Codethink):

> The latest mainline kernel branch fails to build csky and mips allmodconfig
> with gcc-12.
> 
> mips error is:
> 
> In function 'memcmp',
>      inlined from 'bacmp' at ./include/net/bluetooth/bluetooth.h:347:9,
>      inlined from 'l2cap_global_chan_by_psm' at net/bluetooth/l2cap_core.c:2003:15:
> ./include/linux/fortify-string.h:44:33: error: '__builtin_memcmp' specified bound 6 exceeds source size 0 [-Werror=stringop-overread]
>     44 | #define __underlying_memcmp     __builtin_memcmp
>        |                                 ^
> ./include/linux/fortify-string.h:420:16: note: in expansion of macro '__underlying_memcmp'
>    420 |         return __underlying_memcmp(p, q, size);
>        |                ^~~~~~~~~~~~~~~~~~~
> In function 'memcmp',
>      inlined from 'bacmp' at ./include/net/bluetooth/bluetooth.h:347:9,
>      inlined from 'l2cap_global_chan_by_psm' at net/bluetooth/l2cap_core.c:2004:15:
> ./include/linux/fortify-string.h:44:33: error: '__builtin_memcmp' specified bound 6 exceeds source size 0 [-Werror=stringop-overread]
>     44 | #define __underlying_memcmp     __builtin_memcmp
>        |                                 ^
> ./include/linux/fortify-string.h:420:16: note: in expansion of macro '__underlying_memcmp'
>    420 |         return __underlying_memcmp(p, q, size);
>        |                ^~~~~~~~~~~~~~~~~~~
> 
> 
> csky error is:
> 
> In file included from net/bluetooth/l2cap_core.c:37:
> In function 'bacmp',
>      inlined from 'l2cap_global_chan_by_psm' at net/bluetooth/l2cap_core.c:2003:15:
> ./include/net/bluetooth/bluetooth.h:347:16: error: 'memcmp' specified bound 6 exceeds source size 0 [-Werror=stringop-overread]
>    347 |         return memcmp(ba1, ba2, sizeof(bdaddr_t));
>        |                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> In function 'bacmp',
>      inlined from 'l2cap_global_chan_by_psm' at net/bluetooth/l2cap_core.c:2004:15:
> ./include/net/bluetooth/bluetooth.h:347:16: error: 'memcmp' specified bound 6 exceeds source size 0 [-Werror=stringop-overread]
>    347 |         return memcmp(ba1, ba2, sizeof(bdaddr_t));
>        |                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> 
> git bisect pointed to 332f1795ca20 ("Bluetooth: L2CAP: Fix l2cap_global_chan_by_psm regression").
> And, reverting that commit has fixed the build failure.
> 
> Already reported at https://lore.kernel.org/lkml/YvVQEDs75pxSgxjM@debian/
> and Jacub is looking at a fix, but this is just my usual build failure
> mail of mainline branch for Linus's information.

Does *[PATCH] Bluetooth: L2CAP: Elide a string overflow warning* [1] fix it?


Kind regards,

Paul


PS:

> --
> Regards
> Sudip

Only if you care, your signature delimiter is missing a trailing space [2].


[1]: 
https://lore.kernel.org/linux-bluetooth/20220812055249.8037-1-palmer@rivosinc.com/T/#t
[2]: https://en.wikipedia.org/wiki/Signature_block#Standard_delimiter