Re: strict copy_from_user checks issues?

[Arjan van de Ven]

On Tue, 5 Jan 2010 10:48:57 +0100
Heiko Carstens <heiko.carstens@xxxxxxxxxx> wrote:

> 
> An allyesconfig triggers 52 warnings on s390 (see below). I just
> checked a few but all of them looked like false positives.

hmm I wonder why s390 gcc is so different.... if the s390 gcc isn't
so good at proving things, maybe it's wrong to warn on s390?



> In file included
> from /home2/heicarst/cfu/arch/s390/include/asm/mmu_context.h:13,
> from /home2/heicarst/cfu/arch/s390/include/asm/elf.h:133, from
> include/linux/elf.h:7, from include/linux/module.h:14, from
> drivers/net/tun.c:42: In function 'copy_from_user',
>     inlined from '__tun_chr_ioctl' at drivers/net/tun.c:1124:
> /home2/heicarst/cfu/arch/s390/include/asm/uaccess.h:299: warning:
> call to 'copy_from_user_overflow' declared with attribute warning:
> copy_from_user() buffer size is not provably correct

this one is ... interesting btw... I have trouble myself finding where
the check is done... so I can understand gcc having trouble too.





-- 
Arjan van de Ven 	Intel Open Source Technology Centre
For development, discussion and tips for power savings, 
visit http://www.lesswatts.org
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/