Re: namei_vfat.c array subscript is above array bounds

[OGAWA Hirofumi]

Meelis Roos <mroos@xxxxxxxx> writes:

> I do not know if this is old or new, just noticed it scrolling by while 
> compiling current 4.12+git on 32-bit x86.

Which version of compiler?

Well, latest change of namei_vfat.c is Sep, 2016. And I can't reproduce
it by "gcc version 6.3.0 20170516 (Debian 6.3.0-18)".

>   CC [M]  fs/fat/namei_vfat.o
> In file included from ./arch/x86/include/asm/string.h:2:0,
>                  from ./include/linux/string.h:18,
>                  from ./include/linux/bitmap.h:8,
>                  from ./include/linux/cpumask.h:11,
>                  from ./arch/x86/include/asm/cpumask.h:4,
>                  from ./arch/x86/include/asm/msr.h:10,
>                  from ./arch/x86/include/asm/processor.h:20,
>                  from ./arch/x86/include/asm/cpufeature.h:4,
>                  from ./arch/x86/include/asm/thread_info.h:52,
>                  from ./include/linux/thread_info.h:37,
>                  from ./arch/x86/include/asm/preempt.h:6,
>                  from ./include/linux/preempt.h:80,
>                  from ./include/linux/spinlock.h:50,
>                  from ./include/linux/seqlock.h:35,
>                  from ./include/linux/time.h:5,
>                  from ./include/linux/stat.h:18,
>                  from ./include/linux/module.h:10,
>                  from fs/fat/namei_vfat.c:18:
> fs/fat/namei_vfat.c: In function ‘vfat_add_entry’:
> ./arch/x86/include/asm/string_32.h:74:16: warning: array subscript is above array bounds [-Warray-bounds]
>    *((char *)to + 4) = *((char *)from + 4);
>     ~~~~~~~~~~~~^~~~
> ./arch/x86/include/asm/string_32.h:74:16: warning: array subscript is above array bounds [-Warray-bounds]
> ./arch/x86/include/asm/string_32.h:78:17: warning: array subscript is above array bounds [-Warray-bounds]
>    *((short *)to + 2) = *((short *)from + 2);
>     ~~~~~~~~~~~~~^~~~
> ./arch/x86/include/asm/string_32.h:78:17: warning: array subscript is above array bounds [-Warray-bounds]
> ./arch/x86/include/asm/string_32.h:82:15: warning: array subscript is above array bounds [-Warray-bounds]
>    *((int *)to + 1) = *((int *)from + 1);
>     ~~~~~~~~~~~^~~~
> ./arch/x86/include/asm/string_32.h:82:15: warning: array subscript is above array bounds [-Warray-bounds]

-- 
OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx>