Re: [PATCH v1 1/1] libceph: Amend checking to fix `make W=1` build breakage

[andriy.shevchenko@xxxxxxxxxxxxxxx]

On Mon, Nov 10, 2025 at 07:28:36PM +0000, Viacheslav Dubeyko wrote:
> On Mon, 2025-11-10 at 15:46 +0100, Andy Shevchenko wrote:

...

> >  	ceph_decode_32_safe(p, end, len, e_inval);
> >  	if (len == 0 && incremental)
> >  		return NULL;	/* new_pg_temp: [] to remove */
> > -	if (len > (SIZE_MAX - sizeof(*pg)) / sizeof(u32))
> > +	if ((size_t)len > (SIZE_MAX - sizeof(*pg)) / sizeof(u32))
> >  		return ERR_PTR(-EINVAL);
> >  
> >  	ceph_decode_need(p, end, len * sizeof(u32), e_inval);

> I am guessing... What if we change the declaration of len on size_t, then could
> it be more clear solution here? For example, let's consider this for both cases:
> 
> size_t len, i;
> 
> Could it eliminate the issue and to make the Clang happy? Or could it introduce
> another warnings/issues?

Probably, but the code is pierced with the sizeof(u32) and alike, moreover
size_t is architecture-dependent type, while the set of macros in decode.h
seems to operate on the fixed-width type. That said, I prefer my way of fixing
this. But if you find another, better one, I am all ears!

*Also note, I'm not familiar with the guts of the ceph, so maybe your solution
is the best, but I want more people to confirm this.

-- 
With Best Regards,
Andy Shevchenko