diff options
Diffstat (limited to 'mm/madvise.c')
| -rw-r--r-- | mm/madvise.c | 42 |
1 files changed, 37 insertions, 5 deletions
diff --git a/mm/madvise.c b/mm/madvise.c index 47d8d8a25eae..fd70d6aabc3e 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -80,6 +80,17 @@ static long madvise_behavior(struct vm_area_struct *vma, } new_flags &= ~VM_DONTCOPY; break; + case MADV_WIPEONFORK: + /* MADV_WIPEONFORK is only supported on anonymous memory. */ + if (vma->vm_file || vma->vm_flags & VM_SHARED) { + error = -EINVAL; + goto out; + } + new_flags |= VM_WIPEONFORK; + break; + case MADV_KEEPONFORK: + new_flags &= ~VM_WIPEONFORK; + break; case MADV_DONTDUMP: new_flags |= VM_DONTDUMP; break; @@ -344,7 +355,7 @@ static int madvise_free_pte_range(pmd_t *pmd, unsigned long addr, continue; } - page = vm_normal_page(vma, addr, ptent); + page = _vm_normal_page(vma, addr, ptent, true); if (!page) continue; @@ -368,8 +379,8 @@ static int madvise_free_pte_range(pmd_t *pmd, unsigned long addr, pte_offset_map_lock(mm, pmd, addr, &ptl); goto out; } - put_page(page); unlock_page(page); + put_page(page); pte = pte_offset_map_lock(mm, pmd, addr, &ptl); pte--; addr -= PAGE_SIZE; @@ -613,18 +624,27 @@ static int madvise_inject_error(int behavior, unsigned long start, unsigned long end) { struct page *page; + struct zone *zone; + unsigned int order; if (!capable(CAP_SYS_ADMIN)) return -EPERM; - for (; start < end; start += PAGE_SIZE << - compound_order(compound_head(page))) { + + for (; start < end; start += PAGE_SIZE << order) { int ret; ret = get_user_pages_fast(start, 1, 0, &page); if (ret != 1) return ret; + /* + * When soft offlining hugepages, after migrating the page + * we dissolve it, therefore in the second loop "page" will + * no longer be a compound page, and order will be 0. + */ + order = compound_order(compound_head(page)); + if (PageHWPoison(page)) { put_page(page); continue; @@ -646,6 +666,11 @@ static int madvise_inject_error(int behavior, if (ret) return ret; } + + /* Ensure that all poisoned pages are removed from per-cpu lists */ + for_each_populated_zone(zone) + drain_all_pages(zone); + return 0; } #endif @@ -690,6 +715,8 @@ madvise_behavior_valid(int behavior) #endif case MADV_DONTDUMP: case MADV_DODUMP: + case MADV_WIPEONFORK: + case MADV_KEEPONFORK: #ifdef CONFIG_MEMORY_FAILURE case MADV_SOFT_OFFLINE: case MADV_HWPOISON: @@ -730,6 +757,9 @@ madvise_behavior_valid(int behavior) * MADV_DONTFORK - omit this area from child's address space when forking: * typically, to avoid COWing pages pinned by get_user_pages(). * MADV_DOFORK - cancel MADV_DONTFORK: no longer omit this area when forking. + * MADV_WIPEONFORK - present the child process with zero-filled memory in this + * range after a fork. + * MADV_KEEPONFORK - undo the effect of MADV_WIPEONFORK * MADV_HWPOISON - trigger memory error handler as if the given memory range * were corrupted by unrecoverable hardware memory failure. * MADV_SOFT_OFFLINE - try to soft-offline the given range of memory. @@ -750,7 +780,9 @@ madvise_behavior_valid(int behavior) * zero - success * -EINVAL - start + len < 0, start is not page-aligned, * "behavior" is not a valid value, or application - * is attempting to release locked or shared pages. + * is attempting to release locked or shared pages, + * or the specified address range includes file, Huge TLB, + * MAP_SHARED or VMPFNMAP range. * -ENOMEM - addresses in the specified range are not currently * mapped, or are outside the AS of the process. * -EIO - an I/O error occurred while paging in data. |