On Wed, Aug 12, 2020 at 07:51:08PM +0100, Valentin Schneider wrote:
On 12/08/20 17:35, kernel test robot wrote:
> config: i386-randconfig-s001-20200811 (attached as .config)
> reproduce:
> # sparse version: v0.6.2-168-g9554805c-dirty
> make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=i386
>
>>> kernel/sched/debug.c:279:17: sparse: sparse: non size-preserving pointer to
integer cast
>>> kernel/sched/debug.c:279:17: sparse: sparse: non size-preserving integer to
pointer cast
>
> > 279 tmp += *ppos;
I pretty much copied kernel/sysctl.c::_proc_do_string() and I think that's
exactly the same types here: char* buffer incremented by loff_t offset. It
does look fine to me, but I can't really parse that warning.
The warnings mean that there is a cast from a pointer to an integer with
a size other than the size of a pointer and the other way around.
I's indeed the case here, on i386, where pointers are 32-bit and loff_t
is 64-bit. But yes, I agree:
1) these messages are far from clear
2) these casts are internal and are probably not appropriate here.
I'll look later what can be done at sparse level.
Regards,
-- Luc