Re: namei_vfat.c array subscript is above array bounds

[Meelis Roos]

> > 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?

gcc version 6.4.0 20170704 (Debian 6.4.0-1)

After "touch fs/fat/namei_vfat.c" it appears consitently for me. Debian 
unstable, up to date.

> 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]
> 
> 

-- 
Meelis Roos (mroos@xxxxxxxx)