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

Shanker Donthineni
2016-01-30T01:13:14Z

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
>
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