diff options
| -rw-r--r-- | mm/hugetlb.c | 25 |
1 files changed, 11 insertions, 14 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 3a1501e85483..baac9a09ec0a 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -4257,6 +4257,7 @@ static bool vma_shareable(struct vm_area_struct *vma, unsigned long addr) return false; } +#define ALIGN_DOWN(x, a) __ALIGN_KERNEL((x) - ((a) - 1), (a)) /* * Determine if start,end range within vma could be mapped by shared pmd. * If yes, adjust start and end to cover range associated with possible @@ -4265,25 +4266,21 @@ static bool vma_shareable(struct vm_area_struct *vma, unsigned long addr) void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma, unsigned long *start, unsigned long *end) { - unsigned long check_addr = *start; + unsigned long a_start, a_end; if (!(vma->vm_flags & VM_MAYSHARE)) return; - for (check_addr = *start; check_addr < *end; check_addr += PUD_SIZE) { - unsigned long a_start = check_addr & PUD_MASK; - unsigned long a_end = a_start + PUD_SIZE; + /* Extend the range to be PUD aligned for a worst case scenario */ + a_start = ALIGN_DOWN(*start, PUD_SIZE); + a_end = ALIGN(*end, PUD_SIZE); - /* - * If sharing is possible, adjust start/end if necessary. - */ - if (range_in_vma(vma, a_start, a_end)) { - if (a_start < *start) - *start = a_start; - if (a_end > *end) - *end = a_end; - } - } + /* + * Intersect the range with the vma range, since pmd sharing won't be + * across vma after all + */ + *start = max(vma->vm_start, a_start); + *end = min(vma->vm_end, a_end); } /* |