Merge branch 'akpm' (patches from Andrew)
Merge updates from Andrew Morton: - misc fixes - ocfs2 updates - most of MM * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (118 commits) mm: remove PG_highmem description tools, vm: new option to specify kpageflags file mm/swap.c: make functions and their kernel-doc agree mm, memory_hotplug: fix memmap initialization mm: correct comments regarding do_fault_around() mm: numa: do not trap faults on shared data section pages. hugetlb, mbind: fall back to default policy if vma is NULL hugetlb, mempolicy: fix the mbind hugetlb migration mm, hugetlb: further simplify hugetlb allocation API mm, hugetlb: get rid of surplus page accounting tricks mm, hugetlb: do not rely on overcommit limit during migration mm, hugetlb: integrate giga hugetlb more naturally to the allocation path mm, hugetlb: unify core page allocation accounting and initialization mm/memcontrol.c: try harder to decrease [memory,memsw].limit_in_bytes mm/memcontrol.c: make local symbol static mm/hmm: fix uninitialized use of 'entry' in hmm_vma_walk_pmd() include/linux/mmzone.h: fix explanation of lower bits in the SPARSEMEM mem_map pointer mm/compaction.c: fix comment for try_to_compact_pages() mm/page_ext.c: make page_ext_init a noop when CONFIG_PAGE_EXTENSION but nothing uses it zsmalloc: use U suffix for negative literals being shifted ...
This commit is contained in:
Linus Torvalds
448
kernel/fork.c
448
kernel/fork.c
@@ -77,6 +77,7 @@
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#include <linux/blkdev.h>
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#include <linux/fs_struct.h>
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#include <linux/magic.h>
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#include <linux/sched/mm.h>
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#include <linux/perf_event.h>
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#include <linux/posix-timers.h>
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#include <linux/user-return-notifier.h>
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@@ -390,6 +391,241 @@ void free_task(struct task_struct *tsk)
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}
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EXPORT_SYMBOL(free_task);
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#ifdef CONFIG_MMU
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static __latent_entropy int dup_mmap(struct mm_struct *mm,
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struct mm_struct *oldmm)
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{
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struct vm_area_struct *mpnt, *tmp, *prev, **pprev;
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struct rb_node **rb_link, *rb_parent;
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int retval;
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unsigned long charge;
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LIST_HEAD(uf);
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uprobe_start_dup_mmap();
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if (down_write_killable(&oldmm->mmap_sem)) {
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retval = -EINTR;
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goto fail_uprobe_end;
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}
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flush_cache_dup_mm(oldmm);
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uprobe_dup_mmap(oldmm, mm);
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/*
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* Not linked in yet - no deadlock potential:
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*/
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down_write_nested(&mm->mmap_sem, SINGLE_DEPTH_NESTING);
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/* No ordering required: file already has been exposed. */
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RCU_INIT_POINTER(mm->exe_file, get_mm_exe_file(oldmm));
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mm->total_vm = oldmm->total_vm;
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mm->data_vm = oldmm->data_vm;
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mm->exec_vm = oldmm->exec_vm;
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mm->stack_vm = oldmm->stack_vm;
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rb_link = &mm->mm_rb.rb_node;
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rb_parent = NULL;
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pprev = &mm->mmap;
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retval = ksm_fork(mm, oldmm);
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if (retval)
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goto out;
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retval = khugepaged_fork(mm, oldmm);
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if (retval)
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goto out;
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prev = NULL;
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for (mpnt = oldmm->mmap; mpnt; mpnt = mpnt->vm_next) {
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struct file *file;
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if (mpnt->vm_flags & VM_DONTCOPY) {
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vm_stat_account(mm, mpnt->vm_flags, -vma_pages(mpnt));
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continue;
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}
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charge = 0;
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if (mpnt->vm_flags & VM_ACCOUNT) {
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unsigned long len = vma_pages(mpnt);
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if (security_vm_enough_memory_mm(oldmm, len)) /* sic */
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goto fail_nomem;
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charge = len;
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}
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tmp = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL);
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if (!tmp)
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goto fail_nomem;
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*tmp = *mpnt;
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INIT_LIST_HEAD(&tmp->anon_vma_chain);
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retval = vma_dup_policy(mpnt, tmp);
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if (retval)
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goto fail_nomem_policy;
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tmp->vm_mm = mm;
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retval = dup_userfaultfd(tmp, &uf);
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if (retval)
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goto fail_nomem_anon_vma_fork;
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if (tmp->vm_flags & VM_WIPEONFORK) {
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/* VM_WIPEONFORK gets a clean slate in the child. */
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tmp->anon_vma = NULL;
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if (anon_vma_prepare(tmp))
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goto fail_nomem_anon_vma_fork;
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} else if (anon_vma_fork(tmp, mpnt))
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goto fail_nomem_anon_vma_fork;
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tmp->vm_flags &= ~(VM_LOCKED | VM_LOCKONFAULT);
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tmp->vm_next = tmp->vm_prev = NULL;
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file = tmp->vm_file;
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if (file) {
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struct inode *inode = file_inode(file);
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struct address_space *mapping = file->f_mapping;
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get_file(file);
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if (tmp->vm_flags & VM_DENYWRITE)
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atomic_dec(&inode->i_writecount);
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i_mmap_lock_write(mapping);
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if (tmp->vm_flags & VM_SHARED)
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atomic_inc(&mapping->i_mmap_writable);
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flush_dcache_mmap_lock(mapping);
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/* insert tmp into the share list, just after mpnt */
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vma_interval_tree_insert_after(tmp, mpnt,
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&mapping->i_mmap);
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flush_dcache_mmap_unlock(mapping);
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i_mmap_unlock_write(mapping);
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}
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/*
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* Clear hugetlb-related page reserves for children. This only
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* affects MAP_PRIVATE mappings. Faults generated by the child
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* are not guaranteed to succeed, even if read-only
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*/
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if (is_vm_hugetlb_page(tmp))
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reset_vma_resv_huge_pages(tmp);
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/*
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* Link in the new vma and copy the page table entries.
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*/
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*pprev = tmp;
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pprev = &tmp->vm_next;
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tmp->vm_prev = prev;
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prev = tmp;
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__vma_link_rb(mm, tmp, rb_link, rb_parent);
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rb_link = &tmp->vm_rb.rb_right;
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rb_parent = &tmp->vm_rb;
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mm->map_count++;
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if (!(tmp->vm_flags & VM_WIPEONFORK))
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retval = copy_page_range(mm, oldmm, mpnt);
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if (tmp->vm_ops && tmp->vm_ops->open)
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tmp->vm_ops->open(tmp);
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if (retval)
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goto out;
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}
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/* a new mm has just been created */
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arch_dup_mmap(oldmm, mm);
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retval = 0;
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out:
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up_write(&mm->mmap_sem);
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flush_tlb_mm(oldmm);
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up_write(&oldmm->mmap_sem);
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dup_userfaultfd_complete(&uf);
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fail_uprobe_end:
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uprobe_end_dup_mmap();
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return retval;
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fail_nomem_anon_vma_fork:
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mpol_put(vma_policy(tmp));
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fail_nomem_policy:
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kmem_cache_free(vm_area_cachep, tmp);
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fail_nomem:
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retval = -ENOMEM;
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vm_unacct_memory(charge);
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goto out;
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}
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static inline int mm_alloc_pgd(struct mm_struct *mm)
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{
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mm->pgd = pgd_alloc(mm);
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if (unlikely(!mm->pgd))
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return -ENOMEM;
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return 0;
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}
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static inline void mm_free_pgd(struct mm_struct *mm)
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{
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pgd_free(mm, mm->pgd);
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}
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#else
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static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
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{
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down_write(&oldmm->mmap_sem);
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RCU_INIT_POINTER(mm->exe_file, get_mm_exe_file(oldmm));
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up_write(&oldmm->mmap_sem);
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return 0;
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}
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#define mm_alloc_pgd(mm) (0)
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#define mm_free_pgd(mm)
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#endif /* CONFIG_MMU */
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static void check_mm(struct mm_struct *mm)
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{
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int i;
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for (i = 0; i < NR_MM_COUNTERS; i++) {
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long x = atomic_long_read(&mm->rss_stat.count[i]);
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if (unlikely(x))
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printk(KERN_ALERT "BUG: Bad rss-counter state "
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"mm:%p idx:%d val:%ld\n", mm, i, x);
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}
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if (mm_pgtables_bytes(mm))
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pr_alert("BUG: non-zero pgtables_bytes on freeing mm: %ld\n",
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mm_pgtables_bytes(mm));
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#if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS
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VM_BUG_ON_MM(mm->pmd_huge_pte, mm);
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#endif
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}
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#define allocate_mm() (kmem_cache_alloc(mm_cachep, GFP_KERNEL))
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#define free_mm(mm) (kmem_cache_free(mm_cachep, (mm)))
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/*
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* Called when the last reference to the mm
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* is dropped: either by a lazy thread or by
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* mmput. Free the page directory and the mm.
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*/
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static void __mmdrop(struct mm_struct *mm)
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{
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BUG_ON(mm == &init_mm);
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mm_free_pgd(mm);
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destroy_context(mm);
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hmm_mm_destroy(mm);
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mmu_notifier_mm_destroy(mm);
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check_mm(mm);
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put_user_ns(mm->user_ns);
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free_mm(mm);
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}
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void mmdrop(struct mm_struct *mm)
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{
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if (unlikely(atomic_dec_and_test(&mm->mm_count)))
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__mmdrop(mm);
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}
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EXPORT_SYMBOL_GPL(mmdrop);
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static void mmdrop_async_fn(struct work_struct *work)
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{
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struct mm_struct *mm;
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mm = container_of(work, struct mm_struct, async_put_work);
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__mmdrop(mm);
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}
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static void mmdrop_async(struct mm_struct *mm)
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{
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if (unlikely(atomic_dec_and_test(&mm->mm_count))) {
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INIT_WORK(&mm->async_put_work, mmdrop_async_fn);
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schedule_work(&mm->async_put_work);
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}
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}
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static inline void free_signal_struct(struct signal_struct *sig)
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{
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taskstats_tgid_free(sig);
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@@ -594,181 +830,8 @@ free_tsk:
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return NULL;
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}
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#ifdef CONFIG_MMU
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static __latent_entropy int dup_mmap(struct mm_struct *mm,
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struct mm_struct *oldmm)
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{
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struct vm_area_struct *mpnt, *tmp, *prev, **pprev;
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struct rb_node **rb_link, *rb_parent;
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int retval;
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unsigned long charge;
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LIST_HEAD(uf);
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uprobe_start_dup_mmap();
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if (down_write_killable(&oldmm->mmap_sem)) {
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retval = -EINTR;
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goto fail_uprobe_end;
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}
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flush_cache_dup_mm(oldmm);
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uprobe_dup_mmap(oldmm, mm);
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/*
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* Not linked in yet - no deadlock potential:
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*/
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down_write_nested(&mm->mmap_sem, SINGLE_DEPTH_NESTING);
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/* No ordering required: file already has been exposed. */
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RCU_INIT_POINTER(mm->exe_file, get_mm_exe_file(oldmm));
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mm->total_vm = oldmm->total_vm;
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mm->data_vm = oldmm->data_vm;
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mm->exec_vm = oldmm->exec_vm;
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mm->stack_vm = oldmm->stack_vm;
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rb_link = &mm->mm_rb.rb_node;
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rb_parent = NULL;
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pprev = &mm->mmap;
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retval = ksm_fork(mm, oldmm);
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if (retval)
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goto out;
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retval = khugepaged_fork(mm, oldmm);
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if (retval)
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goto out;
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|
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prev = NULL;
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for (mpnt = oldmm->mmap; mpnt; mpnt = mpnt->vm_next) {
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struct file *file;
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|
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if (mpnt->vm_flags & VM_DONTCOPY) {
|
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vm_stat_account(mm, mpnt->vm_flags, -vma_pages(mpnt));
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continue;
|
||||
}
|
||||
charge = 0;
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||||
if (mpnt->vm_flags & VM_ACCOUNT) {
|
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unsigned long len = vma_pages(mpnt);
|
||||
|
||||
if (security_vm_enough_memory_mm(oldmm, len)) /* sic */
|
||||
goto fail_nomem;
|
||||
charge = len;
|
||||
}
|
||||
tmp = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL);
|
||||
if (!tmp)
|
||||
goto fail_nomem;
|
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*tmp = *mpnt;
|
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INIT_LIST_HEAD(&tmp->anon_vma_chain);
|
||||
retval = vma_dup_policy(mpnt, tmp);
|
||||
if (retval)
|
||||
goto fail_nomem_policy;
|
||||
tmp->vm_mm = mm;
|
||||
retval = dup_userfaultfd(tmp, &uf);
|
||||
if (retval)
|
||||
goto fail_nomem_anon_vma_fork;
|
||||
if (tmp->vm_flags & VM_WIPEONFORK) {
|
||||
/* VM_WIPEONFORK gets a clean slate in the child. */
|
||||
tmp->anon_vma = NULL;
|
||||
if (anon_vma_prepare(tmp))
|
||||
goto fail_nomem_anon_vma_fork;
|
||||
} else if (anon_vma_fork(tmp, mpnt))
|
||||
goto fail_nomem_anon_vma_fork;
|
||||
tmp->vm_flags &= ~(VM_LOCKED | VM_LOCKONFAULT);
|
||||
tmp->vm_next = tmp->vm_prev = NULL;
|
||||
file = tmp->vm_file;
|
||||
if (file) {
|
||||
struct inode *inode = file_inode(file);
|
||||
struct address_space *mapping = file->f_mapping;
|
||||
|
||||
get_file(file);
|
||||
if (tmp->vm_flags & VM_DENYWRITE)
|
||||
atomic_dec(&inode->i_writecount);
|
||||
i_mmap_lock_write(mapping);
|
||||
if (tmp->vm_flags & VM_SHARED)
|
||||
atomic_inc(&mapping->i_mmap_writable);
|
||||
flush_dcache_mmap_lock(mapping);
|
||||
/* insert tmp into the share list, just after mpnt */
|
||||
vma_interval_tree_insert_after(tmp, mpnt,
|
||||
&mapping->i_mmap);
|
||||
flush_dcache_mmap_unlock(mapping);
|
||||
i_mmap_unlock_write(mapping);
|
||||
}
|
||||
|
||||
/*
|
||||
* Clear hugetlb-related page reserves for children. This only
|
||||
* affects MAP_PRIVATE mappings. Faults generated by the child
|
||||
* are not guaranteed to succeed, even if read-only
|
||||
*/
|
||||
if (is_vm_hugetlb_page(tmp))
|
||||
reset_vma_resv_huge_pages(tmp);
|
||||
|
||||
/*
|
||||
* Link in the new vma and copy the page table entries.
|
||||
*/
|
||||
*pprev = tmp;
|
||||
pprev = &tmp->vm_next;
|
||||
tmp->vm_prev = prev;
|
||||
prev = tmp;
|
||||
|
||||
__vma_link_rb(mm, tmp, rb_link, rb_parent);
|
||||
rb_link = &tmp->vm_rb.rb_right;
|
||||
rb_parent = &tmp->vm_rb;
|
||||
|
||||
mm->map_count++;
|
||||
if (!(tmp->vm_flags & VM_WIPEONFORK))
|
||||
retval = copy_page_range(mm, oldmm, mpnt);
|
||||
|
||||
if (tmp->vm_ops && tmp->vm_ops->open)
|
||||
tmp->vm_ops->open(tmp);
|
||||
|
||||
if (retval)
|
||||
goto out;
|
||||
}
|
||||
/* a new mm has just been created */
|
||||
retval = arch_dup_mmap(oldmm, mm);
|
||||
out:
|
||||
up_write(&mm->mmap_sem);
|
||||
flush_tlb_mm(oldmm);
|
||||
up_write(&oldmm->mmap_sem);
|
||||
dup_userfaultfd_complete(&uf);
|
||||
fail_uprobe_end:
|
||||
uprobe_end_dup_mmap();
|
||||
return retval;
|
||||
fail_nomem_anon_vma_fork:
|
||||
mpol_put(vma_policy(tmp));
|
||||
fail_nomem_policy:
|
||||
kmem_cache_free(vm_area_cachep, tmp);
|
||||
fail_nomem:
|
||||
retval = -ENOMEM;
|
||||
vm_unacct_memory(charge);
|
||||
goto out;
|
||||
}
|
||||
|
||||
static inline int mm_alloc_pgd(struct mm_struct *mm)
|
||||
{
|
||||
mm->pgd = pgd_alloc(mm);
|
||||
if (unlikely(!mm->pgd))
|
||||
return -ENOMEM;
|
||||
return 0;
|
||||
}
|
||||
|
||||
static inline void mm_free_pgd(struct mm_struct *mm)
|
||||
{
|
||||
pgd_free(mm, mm->pgd);
|
||||
}
|
||||
#else
|
||||
static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
|
||||
{
|
||||
down_write(&oldmm->mmap_sem);
|
||||
RCU_INIT_POINTER(mm->exe_file, get_mm_exe_file(oldmm));
|
||||
up_write(&oldmm->mmap_sem);
|
||||
return 0;
|
||||
}
|
||||
#define mm_alloc_pgd(mm) (0)
|
||||
#define mm_free_pgd(mm)
|
||||
#endif /* CONFIG_MMU */
|
||||
|
||||
__cacheline_aligned_in_smp DEFINE_SPINLOCK(mmlist_lock);
|
||||
|
||||
#define allocate_mm() (kmem_cache_alloc(mm_cachep, GFP_KERNEL))
|
||||
#define free_mm(mm) (kmem_cache_free(mm_cachep, (mm)))
|
||||
|
||||
static unsigned long default_dump_filter = MMF_DUMP_FILTER_DEFAULT;
|
||||
|
||||
static int __init coredump_filter_setup(char *s)
|
||||
@@ -858,27 +921,6 @@ fail_nopgd:
|
||||
return NULL;
|
||||
}
|
||||
|
||||
static void check_mm(struct mm_struct *mm)
|
||||
{
|
||||
int i;
|
||||
|
||||
for (i = 0; i < NR_MM_COUNTERS; i++) {
|
||||
long x = atomic_long_read(&mm->rss_stat.count[i]);
|
||||
|
||||
if (unlikely(x))
|
||||
printk(KERN_ALERT "BUG: Bad rss-counter state "
|
||||
"mm:%p idx:%d val:%ld\n", mm, i, x);
|
||||
}
|
||||
|
||||
if (mm_pgtables_bytes(mm))
|
||||
pr_alert("BUG: non-zero pgtables_bytes on freeing mm: %ld\n",
|
||||
mm_pgtables_bytes(mm));
|
||||
|
||||
#if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS
|
||||
VM_BUG_ON_MM(mm->pmd_huge_pte, mm);
|
||||
#endif
|
||||
}
|
||||
|
||||
/*
|
||||
* Allocate and initialize an mm_struct.
|
||||
*/
|
||||
@@ -894,24 +936,6 @@ struct mm_struct *mm_alloc(void)
|
||||
return mm_init(mm, current, current_user_ns());
|
||||
}
|
||||
|
||||
/*
|
||||
* Called when the last reference to the mm
|
||||
* is dropped: either by a lazy thread or by
|
||||
* mmput. Free the page directory and the mm.
|
||||
*/
|
||||
void __mmdrop(struct mm_struct *mm)
|
||||
{
|
||||
BUG_ON(mm == &init_mm);
|
||||
mm_free_pgd(mm);
|
||||
destroy_context(mm);
|
||||
hmm_mm_destroy(mm);
|
||||
mmu_notifier_mm_destroy(mm);
|
||||
check_mm(mm);
|
||||
put_user_ns(mm->user_ns);
|
||||
free_mm(mm);
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(__mmdrop);
|
||||
|
||||
static inline void __mmput(struct mm_struct *mm)
|
||||
{
|
||||
VM_BUG_ON(atomic_read(&mm->mm_users));
|
||||
|
||||
@@ -1374,13 +1374,6 @@ static struct ctl_table vm_table[] = {
|
||||
.mode = 0644,
|
||||
.proc_handler = proc_dointvec,
|
||||
},
|
||||
{
|
||||
.procname = "hugepages_treat_as_movable",
|
||||
.data = &hugepages_treat_as_movable,
|
||||
.maxlen = sizeof(int),
|
||||
.mode = 0644,
|
||||
.proc_handler = proc_dointvec,
|
||||
},
|
||||
{
|
||||
.procname = "nr_overcommit_hugepages",
|
||||
.data = NULL,
|
||||
|
||||
Reference in New Issue
Block a user