diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/bootmem.c | 6 | ||||
| -rw-r--r-- | mm/memory.c | 67 | ||||
| -rw-r--r-- | mm/migrate.c | 10 | ||||
| -rw-r--r-- | mm/slab.c | 5 |
4 files changed, 78 insertions, 10 deletions
diff --git a/mm/bootmem.c b/mm/bootmem.c index e8fb927..8d9f60e 100644 --- a/mm/bootmem.c +++ b/mm/bootmem.c @@ -442,15 +442,17 @@ unsigned long __init init_bootmem_node(pg_data_t *pgdat, unsigned long freepfn, return init_bootmem_core(pgdat, freepfn, startpfn, endpfn); } -void __init reserve_bootmem_node(pg_data_t *pgdat, unsigned long physaddr, +int __init reserve_bootmem_node(pg_data_t *pgdat, unsigned long physaddr, unsigned long size, int flags) { int ret; ret = can_reserve_bootmem_core(pgdat->bdata, physaddr, size, flags); if (ret < 0) - return; + return -ENOMEM; reserve_bootmem_core(pgdat->bdata, physaddr, size, flags); + + return 0; } void __init free_bootmem_node(pg_data_t *pgdat, unsigned long physaddr, diff --git a/mm/memory.c b/mm/memory.c index 19e0ae9..d14b251 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -999,17 +999,15 @@ struct page *follow_page(struct vm_area_struct *vma, unsigned long address, goto no_page_table; ptep = pte_offset_map_lock(mm, pmd, address, &ptl); - if (!ptep) - goto out; pte = *ptep; if (!pte_present(pte)) - goto unlock; + goto no_page; if ((flags & FOLL_WRITE) && !pte_write(pte)) goto unlock; page = vm_normal_page(vma, address, pte); if (unlikely(!page)) - goto unlock; + goto bad_page; if (flags & FOLL_GET) get_page(page); @@ -1024,6 +1022,15 @@ unlock: out: return page; +bad_page: + pte_unmap_unlock(ptep, ptl); + return ERR_PTR(-EFAULT); + +no_page: + pte_unmap_unlock(ptep, ptl); + if (!pte_none(pte)) + return page; + /* Fall through to ZERO_PAGE handling */ no_page_table: /* * When core dumping an enormous anonymous area that nobody @@ -1038,6 +1045,26 @@ no_page_table: return page; } +/* Can we do the FOLL_ANON optimization? */ +static inline int use_zero_page(struct vm_area_struct *vma) +{ + /* + * We don't want to optimize FOLL_ANON for make_pages_present() + * when it tries to page in a VM_LOCKED region. As to VM_SHARED, + * we want to get the page from the page tables to make sure + * that we serialize and update with any other user of that + * mapping. + */ + if (vma->vm_flags & (VM_LOCKED | VM_SHARED)) + return 0; + /* + * And if we have a fault or a nopfn routine, it's not an + * anonymous region. + */ + return !vma->vm_ops || + (!vma->vm_ops->fault && !vma->vm_ops->nopfn); +} + int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, unsigned long start, int len, int write, int force, struct page **pages, struct vm_area_struct **vmas) @@ -1112,8 +1139,7 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, foll_flags = FOLL_TOUCH; if (pages) foll_flags |= FOLL_GET; - if (!write && !(vma->vm_flags & VM_LOCKED) && - (!vma->vm_ops || !vma->vm_ops->fault)) + if (!write && use_zero_page(vma)) foll_flags |= FOLL_ANON; do { @@ -1159,6 +1185,8 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, cond_resched(); } + if (IS_ERR(page)) + return i ? i : PTR_ERR(page); if (pages) { pages[i] = page; @@ -1757,7 +1785,6 @@ gotten: page_table = pte_offset_map_lock(mm, pmd, address, &ptl); if (likely(pte_same(*page_table, orig_pte))) { if (old_page) { - page_remove_rmap(old_page, vma); if (!PageAnon(old_page)) { dec_mm_counter(mm, file_rss); inc_mm_counter(mm, anon_rss); @@ -1779,6 +1806,32 @@ gotten: lru_cache_add_active(new_page); page_add_new_anon_rmap(new_page, vma, address); + if (old_page) { + /* + * Only after switching the pte to the new page may + * we remove the mapcount here. Otherwise another + * process may come and find the rmap count decremented + * before the pte is switched to the new page, and + * "reuse" the old page writing into it while our pte + * here still points into it and can be read by other + * threads. + * + * The critical issue is to order this + * page_remove_rmap with the ptp_clear_flush above. + * Those stores are ordered by (if nothing else,) + * the barrier present in the atomic_add_negative + * in page_remove_rmap. + * + * Then the TLB flush in ptep_clear_flush ensures that + * no process can access the old page before the + * decremented mapcount is visible. And the old page + * cannot be reused until after the decremented + * mapcount is visible. So transitively, TLBs to + * old page will be flushed before it can be reused. + */ + page_remove_rmap(old_page, vma); + } + /* Free the old page.. */ new_page = old_page; ret |= VM_FAULT_WRITE; diff --git a/mm/migrate.c b/mm/migrate.c index 449d77d..112bcae 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -865,6 +865,11 @@ static int do_move_pages(struct mm_struct *mm, struct page_to_node *pm, goto set_status; page = follow_page(vma, pp->addr, FOLL_GET); + + err = PTR_ERR(page); + if (IS_ERR(page)) + goto set_status; + err = -ENOENT; if (!page) goto set_status; @@ -928,6 +933,11 @@ static int do_pages_stat(struct mm_struct *mm, struct page_to_node *pm) goto set_status; page = follow_page(vma, pm->addr, 0); + + err = PTR_ERR(page); + if (IS_ERR(page)) + goto set_status; + err = -ENOENT; /* Use PageReserved to check for zero page */ if (!page || PageReserved(page)) @@ -3263,9 +3263,12 @@ retry: if (cpuset_zone_allowed_hardwall(zone, flags) && cache->nodelists[nid] && - cache->nodelists[nid]->free_objects) + cache->nodelists[nid]->free_objects) { obj = ____cache_alloc_node(cache, flags | GFP_THISNODE, nid); + if (obj) + break; + } } if (!obj) { |