Re: [PATCH] mm: correct type for vmalloc vm_flags fields

[Lorenzo Stoakes <lorenzo.stoakes@oracle.com>]

Again to emphasise - the original series is not broken, this is just laying
the ground for a future change and fixing places where _that_ change would
be broken (and picked up then).

So there's nothing to be worried about here.

On Tue, Jul 29, 2025 at 01:28:31PM +0100, Pedro Falcato wrote:
> On Tue, Jul 29, 2025 at 12:49:06PM +0100, Lorenzo Stoakes wrote:
> > Several functions refer to the unfortunately named 'vm_flags' field when
> > referencing vmalloc flags, which happens to be the precise same name used
> > for VMA flags.
> >
> > As a result these were erroneously changed to use the vm_flags_t type
> > (which currently is a typedef equivalent to unsigned long).
> >
> > Currently this has no impact, but in future when vm_flags_t changes this
> > will result in issues, so change the type to unsigned long to account for
> > this.
> >
> > Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
> > Reported-by: Harry Yoo <harry.yoo@oracle.com>
> > Closes: https://lore.kernel.org/all/aIgSpAnU8EaIcqd9@hyeyoo/
>
> Reviewed-by: Pedro Falcato <pfalcato@suse.de>

Thanks.

>
> I think the existence of this mistake really tells us that we _really_ need some sort
> of type checking of this stuff, in the future.

I guess you forgot the off-list conversation in which I said I was going to
do exactly what you suggest here...

But yes, I already felt this way (as there seems no sensible way to make
static tools check carefully, and it's enormously easy to miss something),
and this is precisely what I intend to do.