On 09/08/16 16:04, Nicholas Piggin wrote:
On Tue, 9 Aug 2016 14:43:00 +1000
Balbir Singh [off-list ref] wrote:
quoted
On 03/08/16 18:40, Alexey Kardashevskiy wrote:
quoted
quoted
-long mm_iommu_get(unsigned long ua, unsigned long entries,
+long mm_iommu_get(struct mm_struct *mm, unsigned long ua, unsigned long entries,
struct mm_iommu_table_group_mem_t **pmem)
{
struct mm_iommu_table_group_mem_t *mem;
long i, j, ret = 0, locked_entries = 0;
struct page *page = NULL;
- if (!current || !current->mm)
- return -ESRCH; /* process exited */
VM_BUG_ON(mm == NULL)?
quoted
quoted
@@ -128,10 +129,17 @@ static long tce_iommu_register_pages(struct tce_container *container,
((vaddr + size) < vaddr))
return -EINVAL;
- ret = mm_iommu_get(vaddr, entries, &mem);
+ if (!container->mm) {
+ if (!current->mm)
+ return -ESRCH; /* process exited */
You may even want to check for PF_EXITING and ignore those tasks?
These are related to some of the questions I had about the patch.
But I think it makes sense just to take this approach as a minimal
bug fix without changing logic too much or adding BUG_ONs, and then
if we we can consider how iommu takes references to mm and uses it
(if anybody finds the time).
Agreed
Balbir