diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/hugetlb.c | 22 | ||||
| -rw-r--r-- | mm/memory.c | 14 |
2 files changed, 24 insertions, 12 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index a1b30d45459e..61d380678030 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -394,6 +394,28 @@ out: return ret; } +/* + * On ia64 at least, it is possible to receive a hugetlb fault from a + * stale zero entry left in the TLB from earlier hardware prefetching. + * Low-level arch code should already have flushed the stale entry as + * part of its fault handling, but we do need to accept this minor fault + * and return successfully. Whereas the "normal" case is that this is + * an access to a hugetlb page which has been truncated off since mmap. + */ +int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, + unsigned long address, int write_access) +{ + int ret = VM_FAULT_SIGBUS; + pte_t *pte; + + spin_lock(&mm->page_table_lock); + pte = huge_pte_offset(mm, address); + if (pte && !pte_none(*pte)) + ret = VM_FAULT_MINOR; + spin_unlock(&mm->page_table_lock); + return ret; +} + int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, struct page **pages, struct vm_area_struct **vmas, unsigned long *position, int *length, int i) diff --git a/mm/memory.c b/mm/memory.c index 8c88b973abc5..1db40e935e55 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2045,18 +2045,8 @@ int __handle_mm_fault(struct mm_struct *mm, struct vm_area_struct * vma, inc_page_state(pgfault); - if (unlikely(is_vm_hugetlb_page(vma))) { - if (valid_hugetlb_file_off(vma, address)) - /* We get here only if there was a stale(zero) TLB entry - * (because of HW prefetching). - * Low-level arch code (if needed) should have already - * purged the stale entry as part of this fault handling. - * Here we just return. - */ - return VM_FAULT_MINOR; - else - return VM_FAULT_SIGBUS; /* mapping truncation does this. */ - } + if (unlikely(is_vm_hugetlb_page(vma))) + return hugetlb_fault(mm, vma, address, write_access); /* * We need the page table lock to synchronize with kswapd |