On 20/12/2019 20:57, Jan Kara wrote:
> On Fri 20-12-19 16:06:05, Alexey Kardashevskiy wrote:
>>
>>
>> On 11/12/2019 21:42, Jan Kara wrote:
>>> The last jump to free_exit in mm_iommu_do_alloc() happens after page
>>> pointers in struct mm_iommu_table_group_mem_t were already converted to
>>> physical addresses. Thus calling put_page() on these physical addresses
>>> will likely crash. Convert physical addresses back to page pointers
>>> during the error cleanup.
>>>
>>> Signed-off-by: Jan Kara <j...@suse.cz>
>>> ---
>>> arch/powerpc/mm/book3s64/iommu_api.c | 5 ++++-
>>> 1 file changed, 4 insertions(+), 1 deletion(-)
>>>
>>> Beware, this is completely untested, spotted just by code audit.
>>>
>>> diff --git a/arch/powerpc/mm/book3s64/iommu_api.c
>>> b/arch/powerpc/mm/book3s64/iommu_api.c
>>> index 56cc84520577..06c403381c9c 100644
>>> --- a/arch/powerpc/mm/book3s64/iommu_api.c
>>> +++ b/arch/powerpc/mm/book3s64/iommu_api.c
>>> @@ -154,7 +154,7 @@ static long mm_iommu_do_alloc(struct mm_struct *mm,
>>> unsigned long ua,
>>> (mem2->entries << PAGE_SHIFT)))) {
>>> ret = -EINVAL;
>>> mutex_unlock(&mem_list_mutex);
>>> - goto free_exit;
>>> + goto convert_exit;
>>> }
>>> }
>>>
>>> @@ -166,6 +166,9 @@ static long mm_iommu_do_alloc(struct mm_struct *mm,
>>> unsigned long ua,
>>>
>>> return 0;
>>>
>>> +convert_exit:
>>> + for (i = 0; i < pinned; i++)
>>> + mem->hpages[i] = pfn_to_page(mem->hpas[i] >> PAGE_SHIFT);
>>
>>
>> Good find. Although doing it where you added "goto convert_exit" seems
>> cleaner imho. Thanks,
>
> I don't really care :). V2 attached.
Usually patches are posted using git send-mail, not as attachment. A
nit: v2 has now curly braces which v1 did not.
Either way, v2 is correct.
Tested-by: Alexey Kardashevskiy <a...@ozlabs.ru>
Reviewed-by: Alexey Kardashevskiy <a...@ozlabs.ru>
--
Alexey
