Re: [PATCH v2] irqchip: gicv3-its: Fix memory leak in its_free_tables()

[Shanker Donthineni]

On 01/29/2016 02:30 AM, Thomas Gleixner wrote:
> On Thu, 28 Jan 2016, Shanker Donthineni wrote:
> > @@ -807,9 +810,10 @@ static void its_free_tables(struct its_node *its)
> >   	int i;
> >   
> >   	for (i = 0; i < GITS_BASER_NR_REGS; i++) {
> > -		if (its->tables[i]) {
> > -			free_page((unsigned long)its->tables[i]);
> > -			its->tables[i] = NULL;
> > +		if (its->tables[i].base) {
> > +			free_pages((unsigned long)its->tables[i].base,
> > +				   get_order(its->tables[i].size));
> > +			its->tables[i].base = NULL;
> >   		}
> >   	}
> >   }
> > @@ -880,6 +884,7 @@ retry_alloc_baser:
> >   		if (alloc_pages > GITS_BASER_PAGES_MAX) {
> >   			alloc_pages = GITS_BASER_PAGES_MAX;
> >   			order = get_order(GITS_BASER_PAGES_MAX * psz);
> > +			alloc_size = (1 << order) * PAGE_SIZE;
> Why don't you record the order instead of converting back and forth ?
I can use page order information to fix memory leak and I will post v3 
patch with your suggestion.


We have another coding BUG which is related to not refreshing alloc_size 
whenever order changes.
Because we are not updating alloc_size variable here, later part of the 
code logic uses incorrect
alloc_size value in two places as shown below.

Code snippet-1:

            if (!shr) {
                cache = GITS_BASER_nC;
                __flush_dcache_area(base, alloc_size);
            }

Code snippet-2:

        pr_info("ITS: allocated %d %s @%lx (psz %dK, shr %d)\n",
            (int)(alloc_size / entry_size),
            its_base_type_string[type],
            (unsigned long)virt_to_phys(base),
            psz / SZ_1K, (int)shr >> GITS_BASER_SHAREABILITY_SHIFT);


How do you suggest I fix the second problem? Should I create another 
patch or include in v3 patch?

> Thanks,
>
> 	tglx
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel