v4.19.13 snapshot.
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
new file mode 100644
index 0000000..149b6f4
--- /dev/null
+++ b/mm/mempolicy.c
@@ -0,0 +1,2906 @@
+/*
+ * Simple NUMA memory policy for the Linux kernel.
+ *
+ * Copyright 2003,2004 Andi Kleen, SuSE Labs.
+ * (C) Copyright 2005 Christoph Lameter, Silicon Graphics, Inc.
+ * Subject to the GNU Public License, version 2.
+ *
+ * NUMA policy allows the user to give hints in which node(s) memory should
+ * be allocated.
+ *
+ * Support four policies per VMA and per process:
+ *
+ * The VMA policy has priority over the process policy for a page fault.
+ *
+ * interleave Allocate memory interleaved over a set of nodes,
+ * with normal fallback if it fails.
+ * For VMA based allocations this interleaves based on the
+ * offset into the backing object or offset into the mapping
+ * for anonymous memory. For process policy an process counter
+ * is used.
+ *
+ * bind Only allocate memory on a specific set of nodes,
+ * no fallback.
+ * FIXME: memory is allocated starting with the first node
+ * to the last. It would be better if bind would truly restrict
+ * the allocation to memory nodes instead
+ *
+ * preferred Try a specific node first before normal fallback.
+ * As a special case NUMA_NO_NODE here means do the allocation
+ * on the local CPU. This is normally identical to default,
+ * but useful to set in a VMA when you have a non default
+ * process policy.
+ *
+ * default Allocate on the local node first, or when on a VMA
+ * use the process policy. This is what Linux always did
+ * in a NUMA aware kernel and still does by, ahem, default.
+ *
+ * The process policy is applied for most non interrupt memory allocations
+ * in that process' context. Interrupts ignore the policies and always
+ * try to allocate on the local CPU. The VMA policy is only applied for memory
+ * allocations for a VMA in the VM.
+ *
+ * Currently there are a few corner cases in swapping where the policy
+ * is not applied, but the majority should be handled. When process policy
+ * is used it is not remembered over swap outs/swap ins.
+ *
+ * Only the highest zone in the zone hierarchy gets policied. Allocations
+ * requesting a lower zone just use default policy. This implies that
+ * on systems with highmem kernel lowmem allocation don't get policied.
+ * Same with GFP_DMA allocations.
+ *
+ * For shmfs/tmpfs/hugetlbfs shared memory the policy is shared between
+ * all users and remembered even when nobody has memory mapped.
+ */
+
+/* Notebook:
+ fix mmap readahead to honour policy and enable policy for any page cache
+ object
+ statistics for bigpages
+ global policy for page cache? currently it uses process policy. Requires
+ first item above.
+ handle mremap for shared memory (currently ignored for the policy)
+ grows down?
+ make bind policy root only? It can trigger oom much faster and the
+ kernel is not always grateful with that.
+*/
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/mempolicy.h>
+#include <linux/mm.h>
+#include <linux/highmem.h>
+#include <linux/hugetlb.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/sched/mm.h>
+#include <linux/sched/numa_balancing.h>
+#include <linux/sched/task.h>
+#include <linux/nodemask.h>
+#include <linux/cpuset.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/export.h>
+#include <linux/nsproxy.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <linux/compat.h>
+#include <linux/ptrace.h>
+#include <linux/swap.h>
+#include <linux/seq_file.h>
+#include <linux/proc_fs.h>
+#include <linux/migrate.h>
+#include <linux/ksm.h>
+#include <linux/rmap.h>
+#include <linux/security.h>
+#include <linux/syscalls.h>
+#include <linux/ctype.h>
+#include <linux/mm_inline.h>
+#include <linux/mmu_notifier.h>
+#include <linux/printk.h>
+#include <linux/swapops.h>
+
+#include <asm/tlbflush.h>
+#include <linux/uaccess.h>
+
+#include "internal.h"
+
+/* Internal flags */
+#define MPOL_MF_DISCONTIG_OK (MPOL_MF_INTERNAL << 0) /* Skip checks for continuous vmas */
+#define MPOL_MF_INVERT (MPOL_MF_INTERNAL << 1) /* Invert check for nodemask */
+
+static struct kmem_cache *policy_cache;
+static struct kmem_cache *sn_cache;
+
+/* Highest zone. An specific allocation for a zone below that is not
+ policied. */
+enum zone_type policy_zone = 0;
+
+/*
+ * run-time system-wide default policy => local allocation
+ */
+static struct mempolicy default_policy = {
+ .refcnt = ATOMIC_INIT(1), /* never free it */
+ .mode = MPOL_PREFERRED,
+ .flags = MPOL_F_LOCAL,
+};
+
+static struct mempolicy preferred_node_policy[MAX_NUMNODES];
+
+struct mempolicy *get_task_policy(struct task_struct *p)
+{
+ struct mempolicy *pol = p->mempolicy;
+ int node;
+
+ if (pol)
+ return pol;
+
+ node = numa_node_id();
+ if (node != NUMA_NO_NODE) {
+ pol = &preferred_node_policy[node];
+ /* preferred_node_policy is not initialised early in boot */
+ if (pol->mode)
+ return pol;
+ }
+
+ return &default_policy;
+}
+
+static const struct mempolicy_operations {
+ int (*create)(struct mempolicy *pol, const nodemask_t *nodes);
+ void (*rebind)(struct mempolicy *pol, const nodemask_t *nodes);
+} mpol_ops[MPOL_MAX];
+
+static inline int mpol_store_user_nodemask(const struct mempolicy *pol)
+{
+ return pol->flags & MPOL_MODE_FLAGS;
+}
+
+static void mpol_relative_nodemask(nodemask_t *ret, const nodemask_t *orig,
+ const nodemask_t *rel)
+{
+ nodemask_t tmp;
+ nodes_fold(tmp, *orig, nodes_weight(*rel));
+ nodes_onto(*ret, tmp, *rel);
+}
+
+static int mpol_new_interleave(struct mempolicy *pol, const nodemask_t *nodes)
+{
+ if (nodes_empty(*nodes))
+ return -EINVAL;
+ pol->v.nodes = *nodes;
+ return 0;
+}
+
+static int mpol_new_preferred(struct mempolicy *pol, const nodemask_t *nodes)
+{
+ if (!nodes)
+ pol->flags |= MPOL_F_LOCAL; /* local allocation */
+ else if (nodes_empty(*nodes))
+ return -EINVAL; /* no allowed nodes */
+ else
+ pol->v.preferred_node = first_node(*nodes);
+ return 0;
+}
+
+static int mpol_new_bind(struct mempolicy *pol, const nodemask_t *nodes)
+{
+ if (nodes_empty(*nodes))
+ return -EINVAL;
+ pol->v.nodes = *nodes;
+ return 0;
+}
+
+/*
+ * mpol_set_nodemask is called after mpol_new() to set up the nodemask, if
+ * any, for the new policy. mpol_new() has already validated the nodes
+ * parameter with respect to the policy mode and flags. But, we need to
+ * handle an empty nodemask with MPOL_PREFERRED here.
+ *
+ * Must be called holding task's alloc_lock to protect task's mems_allowed
+ * and mempolicy. May also be called holding the mmap_semaphore for write.
+ */
+static int mpol_set_nodemask(struct mempolicy *pol,
+ const nodemask_t *nodes, struct nodemask_scratch *nsc)
+{
+ int ret;
+
+ /* if mode is MPOL_DEFAULT, pol is NULL. This is right. */
+ if (pol == NULL)
+ return 0;
+ /* Check N_MEMORY */
+ nodes_and(nsc->mask1,
+ cpuset_current_mems_allowed, node_states[N_MEMORY]);
+
+ VM_BUG_ON(!nodes);
+ if (pol->mode == MPOL_PREFERRED && nodes_empty(*nodes))
+ nodes = NULL; /* explicit local allocation */
+ else {
+ if (pol->flags & MPOL_F_RELATIVE_NODES)
+ mpol_relative_nodemask(&nsc->mask2, nodes, &nsc->mask1);
+ else
+ nodes_and(nsc->mask2, *nodes, nsc->mask1);
+
+ if (mpol_store_user_nodemask(pol))
+ pol->w.user_nodemask = *nodes;
+ else
+ pol->w.cpuset_mems_allowed =
+ cpuset_current_mems_allowed;
+ }
+
+ if (nodes)
+ ret = mpol_ops[pol->mode].create(pol, &nsc->mask2);
+ else
+ ret = mpol_ops[pol->mode].create(pol, NULL);
+ return ret;
+}
+
+/*
+ * This function just creates a new policy, does some check and simple
+ * initialization. You must invoke mpol_set_nodemask() to set nodes.
+ */
+static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags,
+ nodemask_t *nodes)
+{
+ struct mempolicy *policy;
+
+ pr_debug("setting mode %d flags %d nodes[0] %lx\n",
+ mode, flags, nodes ? nodes_addr(*nodes)[0] : NUMA_NO_NODE);
+
+ if (mode == MPOL_DEFAULT) {
+ if (nodes && !nodes_empty(*nodes))
+ return ERR_PTR(-EINVAL);
+ return NULL;
+ }
+ VM_BUG_ON(!nodes);
+
+ /*
+ * MPOL_PREFERRED cannot be used with MPOL_F_STATIC_NODES or
+ * MPOL_F_RELATIVE_NODES if the nodemask is empty (local allocation).
+ * All other modes require a valid pointer to a non-empty nodemask.
+ */
+ if (mode == MPOL_PREFERRED) {
+ if (nodes_empty(*nodes)) {
+ if (((flags & MPOL_F_STATIC_NODES) ||
+ (flags & MPOL_F_RELATIVE_NODES)))
+ return ERR_PTR(-EINVAL);
+ }
+ } else if (mode == MPOL_LOCAL) {
+ if (!nodes_empty(*nodes) ||
+ (flags & MPOL_F_STATIC_NODES) ||
+ (flags & MPOL_F_RELATIVE_NODES))
+ return ERR_PTR(-EINVAL);
+ mode = MPOL_PREFERRED;
+ } else if (nodes_empty(*nodes))
+ return ERR_PTR(-EINVAL);
+ policy = kmem_cache_alloc(policy_cache, GFP_KERNEL);
+ if (!policy)
+ return ERR_PTR(-ENOMEM);
+ atomic_set(&policy->refcnt, 1);
+ policy->mode = mode;
+ policy->flags = flags;
+
+ return policy;
+}
+
+/* Slow path of a mpol destructor. */
+void __mpol_put(struct mempolicy *p)
+{
+ if (!atomic_dec_and_test(&p->refcnt))
+ return;
+ kmem_cache_free(policy_cache, p);
+}
+
+static void mpol_rebind_default(struct mempolicy *pol, const nodemask_t *nodes)
+{
+}
+
+static void mpol_rebind_nodemask(struct mempolicy *pol, const nodemask_t *nodes)
+{
+ nodemask_t tmp;
+
+ if (pol->flags & MPOL_F_STATIC_NODES)
+ nodes_and(tmp, pol->w.user_nodemask, *nodes);
+ else if (pol->flags & MPOL_F_RELATIVE_NODES)
+ mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes);
+ else {
+ nodes_remap(tmp, pol->v.nodes,pol->w.cpuset_mems_allowed,
+ *nodes);
+ pol->w.cpuset_mems_allowed = tmp;
+ }
+
+ if (nodes_empty(tmp))
+ tmp = *nodes;
+
+ pol->v.nodes = tmp;
+}
+
+static void mpol_rebind_preferred(struct mempolicy *pol,
+ const nodemask_t *nodes)
+{
+ nodemask_t tmp;
+
+ if (pol->flags & MPOL_F_STATIC_NODES) {
+ int node = first_node(pol->w.user_nodemask);
+
+ if (node_isset(node, *nodes)) {
+ pol->v.preferred_node = node;
+ pol->flags &= ~MPOL_F_LOCAL;
+ } else
+ pol->flags |= MPOL_F_LOCAL;
+ } else if (pol->flags & MPOL_F_RELATIVE_NODES) {
+ mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes);
+ pol->v.preferred_node = first_node(tmp);
+ } else if (!(pol->flags & MPOL_F_LOCAL)) {
+ pol->v.preferred_node = node_remap(pol->v.preferred_node,
+ pol->w.cpuset_mems_allowed,
+ *nodes);
+ pol->w.cpuset_mems_allowed = *nodes;
+ }
+}
+
+/*
+ * mpol_rebind_policy - Migrate a policy to a different set of nodes
+ *
+ * Per-vma policies are protected by mmap_sem. Allocations using per-task
+ * policies are protected by task->mems_allowed_seq to prevent a premature
+ * OOM/allocation failure due to parallel nodemask modification.
+ */
+static void mpol_rebind_policy(struct mempolicy *pol, const nodemask_t *newmask)
+{
+ if (!pol)
+ return;
+ if (!mpol_store_user_nodemask(pol) &&
+ nodes_equal(pol->w.cpuset_mems_allowed, *newmask))
+ return;
+
+ mpol_ops[pol->mode].rebind(pol, newmask);
+}
+
+/*
+ * Wrapper for mpol_rebind_policy() that just requires task
+ * pointer, and updates task mempolicy.
+ *
+ * Called with task's alloc_lock held.
+ */
+
+void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new)
+{
+ mpol_rebind_policy(tsk->mempolicy, new);
+}
+
+/*
+ * Rebind each vma in mm to new nodemask.
+ *
+ * Call holding a reference to mm. Takes mm->mmap_sem during call.
+ */
+
+void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new)
+{
+ struct vm_area_struct *vma;
+
+ down_write(&mm->mmap_sem);
+ for (vma = mm->mmap; vma; vma = vma->vm_next)
+ mpol_rebind_policy(vma->vm_policy, new);
+ up_write(&mm->mmap_sem);
+}
+
+static const struct mempolicy_operations mpol_ops[MPOL_MAX] = {
+ [MPOL_DEFAULT] = {
+ .rebind = mpol_rebind_default,
+ },
+ [MPOL_INTERLEAVE] = {
+ .create = mpol_new_interleave,
+ .rebind = mpol_rebind_nodemask,
+ },
+ [MPOL_PREFERRED] = {
+ .create = mpol_new_preferred,
+ .rebind = mpol_rebind_preferred,
+ },
+ [MPOL_BIND] = {
+ .create = mpol_new_bind,
+ .rebind = mpol_rebind_nodemask,
+ },
+};
+
+static void migrate_page_add(struct page *page, struct list_head *pagelist,
+ unsigned long flags);
+
+struct queue_pages {
+ struct list_head *pagelist;
+ unsigned long flags;
+ nodemask_t *nmask;
+ struct vm_area_struct *prev;
+};
+
+/*
+ * Check if the page's nid is in qp->nmask.
+ *
+ * If MPOL_MF_INVERT is set in qp->flags, check if the nid is
+ * in the invert of qp->nmask.
+ */
+static inline bool queue_pages_required(struct page *page,
+ struct queue_pages *qp)
+{
+ int nid = page_to_nid(page);
+ unsigned long flags = qp->flags;
+
+ return node_isset(nid, *qp->nmask) == !(flags & MPOL_MF_INVERT);
+}
+
+static int queue_pages_pmd(pmd_t *pmd, spinlock_t *ptl, unsigned long addr,
+ unsigned long end, struct mm_walk *walk)
+{
+ int ret = 0;
+ struct page *page;
+ struct queue_pages *qp = walk->private;
+ unsigned long flags;
+
+ if (unlikely(is_pmd_migration_entry(*pmd))) {
+ ret = 1;
+ goto unlock;
+ }
+ page = pmd_page(*pmd);
+ if (is_huge_zero_page(page)) {
+ spin_unlock(ptl);
+ __split_huge_pmd(walk->vma, pmd, addr, false, NULL);
+ goto out;
+ }
+ if (!queue_pages_required(page, qp)) {
+ ret = 1;
+ goto unlock;
+ }
+
+ ret = 1;
+ flags = qp->flags;
+ /* go to thp migration */
+ if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))
+ migrate_page_add(page, qp->pagelist, flags);
+unlock:
+ spin_unlock(ptl);
+out:
+ return ret;
+}
+
+/*
+ * Scan through pages checking if pages follow certain conditions,
+ * and move them to the pagelist if they do.
+ */
+static int queue_pages_pte_range(pmd_t *pmd, unsigned long addr,
+ unsigned long end, struct mm_walk *walk)
+{
+ struct vm_area_struct *vma = walk->vma;
+ struct page *page;
+ struct queue_pages *qp = walk->private;
+ unsigned long flags = qp->flags;
+ int ret;
+ pte_t *pte;
+ spinlock_t *ptl;
+
+ ptl = pmd_trans_huge_lock(pmd, vma);
+ if (ptl) {
+ ret = queue_pages_pmd(pmd, ptl, addr, end, walk);
+ if (ret)
+ return 0;
+ }
+
+ if (pmd_trans_unstable(pmd))
+ return 0;
+
+ pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
+ for (; addr != end; pte++, addr += PAGE_SIZE) {
+ if (!pte_present(*pte))
+ continue;
+ page = vm_normal_page(vma, addr, *pte);
+ if (!page)
+ continue;
+ /*
+ * vm_normal_page() filters out zero pages, but there might
+ * still be PageReserved pages to skip, perhaps in a VDSO.
+ */
+ if (PageReserved(page))
+ continue;
+ if (!queue_pages_required(page, qp))
+ continue;
+ migrate_page_add(page, qp->pagelist, flags);
+ }
+ pte_unmap_unlock(pte - 1, ptl);
+ cond_resched();
+ return 0;
+}
+
+static int queue_pages_hugetlb(pte_t *pte, unsigned long hmask,
+ unsigned long addr, unsigned long end,
+ struct mm_walk *walk)
+{
+#ifdef CONFIG_HUGETLB_PAGE
+ struct queue_pages *qp = walk->private;
+ unsigned long flags = qp->flags;
+ struct page *page;
+ spinlock_t *ptl;
+ pte_t entry;
+
+ ptl = huge_pte_lock(hstate_vma(walk->vma), walk->mm, pte);
+ entry = huge_ptep_get(pte);
+ if (!pte_present(entry))
+ goto unlock;
+ page = pte_page(entry);
+ if (!queue_pages_required(page, qp))
+ goto unlock;
+ /* With MPOL_MF_MOVE, we migrate only unshared hugepage. */
+ if (flags & (MPOL_MF_MOVE_ALL) ||
+ (flags & MPOL_MF_MOVE && page_mapcount(page) == 1))
+ isolate_huge_page(page, qp->pagelist);
+unlock:
+ spin_unlock(ptl);
+#else
+ BUG();
+#endif
+ return 0;
+}
+
+#ifdef CONFIG_NUMA_BALANCING
+/*
+ * This is used to mark a range of virtual addresses to be inaccessible.
+ * These are later cleared by a NUMA hinting fault. Depending on these
+ * faults, pages may be migrated for better NUMA placement.
+ *
+ * This is assuming that NUMA faults are handled using PROT_NONE. If
+ * an architecture makes a different choice, it will need further
+ * changes to the core.
+ */
+unsigned long change_prot_numa(struct vm_area_struct *vma,
+ unsigned long addr, unsigned long end)
+{
+ int nr_updated;
+
+ nr_updated = change_protection(vma, addr, end, PAGE_NONE, 0, 1);
+ if (nr_updated)
+ count_vm_numa_events(NUMA_PTE_UPDATES, nr_updated);
+
+ return nr_updated;
+}
+#else
+static unsigned long change_prot_numa(struct vm_area_struct *vma,
+ unsigned long addr, unsigned long end)
+{
+ return 0;
+}
+#endif /* CONFIG_NUMA_BALANCING */
+
+static int queue_pages_test_walk(unsigned long start, unsigned long end,
+ struct mm_walk *walk)
+{
+ struct vm_area_struct *vma = walk->vma;
+ struct queue_pages *qp = walk->private;
+ unsigned long endvma = vma->vm_end;
+ unsigned long flags = qp->flags;
+
+ if (!vma_migratable(vma))
+ return 1;
+
+ if (endvma > end)
+ endvma = end;
+ if (vma->vm_start > start)
+ start = vma->vm_start;
+
+ if (!(flags & MPOL_MF_DISCONTIG_OK)) {
+ if (!vma->vm_next && vma->vm_end < end)
+ return -EFAULT;
+ if (qp->prev && qp->prev->vm_end < vma->vm_start)
+ return -EFAULT;
+ }
+
+ qp->prev = vma;
+
+ if (flags & MPOL_MF_LAZY) {
+ /* Similar to task_numa_work, skip inaccessible VMAs */
+ if (!is_vm_hugetlb_page(vma) &&
+ (vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE)) &&
+ !(vma->vm_flags & VM_MIXEDMAP))
+ change_prot_numa(vma, start, endvma);
+ return 1;
+ }
+
+ /* queue pages from current vma */
+ if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))
+ return 0;
+ return 1;
+}
+
+/*
+ * Walk through page tables and collect pages to be migrated.
+ *
+ * If pages found in a given range are on a set of nodes (determined by
+ * @nodes and @flags,) it's isolated and queued to the pagelist which is
+ * passed via @private.)
+ */
+static int
+queue_pages_range(struct mm_struct *mm, unsigned long start, unsigned long end,
+ nodemask_t *nodes, unsigned long flags,
+ struct list_head *pagelist)
+{
+ struct queue_pages qp = {
+ .pagelist = pagelist,
+ .flags = flags,
+ .nmask = nodes,
+ .prev = NULL,
+ };
+ struct mm_walk queue_pages_walk = {
+ .hugetlb_entry = queue_pages_hugetlb,
+ .pmd_entry = queue_pages_pte_range,
+ .test_walk = queue_pages_test_walk,
+ .mm = mm,
+ .private = &qp,
+ };
+
+ return walk_page_range(start, end, &queue_pages_walk);
+}
+
+/*
+ * Apply policy to a single VMA
+ * This must be called with the mmap_sem held for writing.
+ */
+static int vma_replace_policy(struct vm_area_struct *vma,
+ struct mempolicy *pol)
+{
+ int err;
+ struct mempolicy *old;
+ struct mempolicy *new;
+
+ pr_debug("vma %lx-%lx/%lx vm_ops %p vm_file %p set_policy %p\n",
+ vma->vm_start, vma->vm_end, vma->vm_pgoff,
+ vma->vm_ops, vma->vm_file,
+ vma->vm_ops ? vma->vm_ops->set_policy : NULL);
+
+ new = mpol_dup(pol);
+ if (IS_ERR(new))
+ return PTR_ERR(new);
+
+ if (vma->vm_ops && vma->vm_ops->set_policy) {
+ err = vma->vm_ops->set_policy(vma, new);
+ if (err)
+ goto err_out;
+ }
+
+ old = vma->vm_policy;
+ vma->vm_policy = new; /* protected by mmap_sem */
+ mpol_put(old);
+
+ return 0;
+ err_out:
+ mpol_put(new);
+ return err;
+}
+
+/* Step 2: apply policy to a range and do splits. */
+static int mbind_range(struct mm_struct *mm, unsigned long start,
+ unsigned long end, struct mempolicy *new_pol)
+{
+ struct vm_area_struct *next;
+ struct vm_area_struct *prev;
+ struct vm_area_struct *vma;
+ int err = 0;
+ pgoff_t pgoff;
+ unsigned long vmstart;
+ unsigned long vmend;
+
+ vma = find_vma(mm, start);
+ if (!vma || vma->vm_start > start)
+ return -EFAULT;
+
+ prev = vma->vm_prev;
+ if (start > vma->vm_start)
+ prev = vma;
+
+ for (; vma && vma->vm_start < end; prev = vma, vma = next) {
+ next = vma->vm_next;
+ vmstart = max(start, vma->vm_start);
+ vmend = min(end, vma->vm_end);
+
+ if (mpol_equal(vma_policy(vma), new_pol))
+ continue;
+
+ pgoff = vma->vm_pgoff +
+ ((vmstart - vma->vm_start) >> PAGE_SHIFT);
+ prev = vma_merge(mm, prev, vmstart, vmend, vma->vm_flags,
+ vma->anon_vma, vma->vm_file, pgoff,
+ new_pol, vma->vm_userfaultfd_ctx);
+ if (prev) {
+ vma = prev;
+ next = vma->vm_next;
+ if (mpol_equal(vma_policy(vma), new_pol))
+ continue;
+ /* vma_merge() joined vma && vma->next, case 8 */
+ goto replace;
+ }
+ if (vma->vm_start != vmstart) {
+ err = split_vma(vma->vm_mm, vma, vmstart, 1);
+ if (err)
+ goto out;
+ }
+ if (vma->vm_end != vmend) {
+ err = split_vma(vma->vm_mm, vma, vmend, 0);
+ if (err)
+ goto out;
+ }
+ replace:
+ err = vma_replace_policy(vma, new_pol);
+ if (err)
+ goto out;
+ }
+
+ out:
+ return err;
+}
+
+/* Set the process memory policy */
+static long do_set_mempolicy(unsigned short mode, unsigned short flags,
+ nodemask_t *nodes)
+{
+ struct mempolicy *new, *old;
+ NODEMASK_SCRATCH(scratch);
+ int ret;
+
+ if (!scratch)
+ return -ENOMEM;
+
+ new = mpol_new(mode, flags, nodes);
+ if (IS_ERR(new)) {
+ ret = PTR_ERR(new);
+ goto out;
+ }
+
+ task_lock(current);
+ ret = mpol_set_nodemask(new, nodes, scratch);
+ if (ret) {
+ task_unlock(current);
+ mpol_put(new);
+ goto out;
+ }
+ old = current->mempolicy;
+ current->mempolicy = new;
+ if (new && new->mode == MPOL_INTERLEAVE)
+ current->il_prev = MAX_NUMNODES-1;
+ task_unlock(current);
+ mpol_put(old);
+ ret = 0;
+out:
+ NODEMASK_SCRATCH_FREE(scratch);
+ return ret;
+}
+
+/*
+ * Return nodemask for policy for get_mempolicy() query
+ *
+ * Called with task's alloc_lock held
+ */
+static void get_policy_nodemask(struct mempolicy *p, nodemask_t *nodes)
+{
+ nodes_clear(*nodes);
+ if (p == &default_policy)
+ return;
+
+ switch (p->mode) {
+ case MPOL_BIND:
+ /* Fall through */
+ case MPOL_INTERLEAVE:
+ *nodes = p->v.nodes;
+ break;
+ case MPOL_PREFERRED:
+ if (!(p->flags & MPOL_F_LOCAL))
+ node_set(p->v.preferred_node, *nodes);
+ /* else return empty node mask for local allocation */
+ break;
+ default:
+ BUG();
+ }
+}
+
+static int lookup_node(unsigned long addr)
+{
+ struct page *p;
+ int err;
+
+ err = get_user_pages(addr & PAGE_MASK, 1, 0, &p, NULL);
+ if (err >= 0) {
+ err = page_to_nid(p);
+ put_page(p);
+ }
+ return err;
+}
+
+/* Retrieve NUMA policy */
+static long do_get_mempolicy(int *policy, nodemask_t *nmask,
+ unsigned long addr, unsigned long flags)
+{
+ int err;
+ struct mm_struct *mm = current->mm;
+ struct vm_area_struct *vma = NULL;
+ struct mempolicy *pol = current->mempolicy;
+
+ if (flags &
+ ~(unsigned long)(MPOL_F_NODE|MPOL_F_ADDR|MPOL_F_MEMS_ALLOWED))
+ return -EINVAL;
+
+ if (flags & MPOL_F_MEMS_ALLOWED) {
+ if (flags & (MPOL_F_NODE|MPOL_F_ADDR))
+ return -EINVAL;
+ *policy = 0; /* just so it's initialized */
+ task_lock(current);
+ *nmask = cpuset_current_mems_allowed;
+ task_unlock(current);
+ return 0;
+ }
+
+ if (flags & MPOL_F_ADDR) {
+ /*
+ * Do NOT fall back to task policy if the
+ * vma/shared policy at addr is NULL. We
+ * want to return MPOL_DEFAULT in this case.
+ */
+ down_read(&mm->mmap_sem);
+ vma = find_vma_intersection(mm, addr, addr+1);
+ if (!vma) {
+ up_read(&mm->mmap_sem);
+ return -EFAULT;
+ }
+ if (vma->vm_ops && vma->vm_ops->get_policy)
+ pol = vma->vm_ops->get_policy(vma, addr);
+ else
+ pol = vma->vm_policy;
+ } else if (addr)
+ return -EINVAL;
+
+ if (!pol)
+ pol = &default_policy; /* indicates default behavior */
+
+ if (flags & MPOL_F_NODE) {
+ if (flags & MPOL_F_ADDR) {
+ err = lookup_node(addr);
+ if (err < 0)
+ goto out;
+ *policy = err;
+ } else if (pol == current->mempolicy &&
+ pol->mode == MPOL_INTERLEAVE) {
+ *policy = next_node_in(current->il_prev, pol->v.nodes);
+ } else {
+ err = -EINVAL;
+ goto out;
+ }
+ } else {
+ *policy = pol == &default_policy ? MPOL_DEFAULT :
+ pol->mode;
+ /*
+ * Internal mempolicy flags must be masked off before exposing
+ * the policy to userspace.
+ */
+ *policy |= (pol->flags & MPOL_MODE_FLAGS);
+ }
+
+ err = 0;
+ if (nmask) {
+ if (mpol_store_user_nodemask(pol)) {
+ *nmask = pol->w.user_nodemask;
+ } else {
+ task_lock(current);
+ get_policy_nodemask(pol, nmask);
+ task_unlock(current);
+ }
+ }
+
+ out:
+ mpol_cond_put(pol);
+ if (vma)
+ up_read(¤t->mm->mmap_sem);
+ return err;
+}
+
+#ifdef CONFIG_MIGRATION
+/*
+ * page migration, thp tail pages can be passed.
+ */
+static void migrate_page_add(struct page *page, struct list_head *pagelist,
+ unsigned long flags)
+{
+ struct page *head = compound_head(page);
+ /*
+ * Avoid migrating a page that is shared with others.
+ */
+ if ((flags & MPOL_MF_MOVE_ALL) || page_mapcount(head) == 1) {
+ if (!isolate_lru_page(head)) {
+ list_add_tail(&head->lru, pagelist);
+ mod_node_page_state(page_pgdat(head),
+ NR_ISOLATED_ANON + page_is_file_cache(head),
+ hpage_nr_pages(head));
+ }
+ }
+}
+
+/* page allocation callback for NUMA node migration */
+struct page *alloc_new_node_page(struct page *page, unsigned long node)
+{
+ if (PageHuge(page))
+ return alloc_huge_page_node(page_hstate(compound_head(page)),
+ node);
+ else if (PageTransHuge(page)) {
+ struct page *thp;
+
+ thp = alloc_pages_node(node,
+ (GFP_TRANSHUGE | __GFP_THISNODE),
+ HPAGE_PMD_ORDER);
+ if (!thp)
+ return NULL;
+ prep_transhuge_page(thp);
+ return thp;
+ } else
+ return __alloc_pages_node(node, GFP_HIGHUSER_MOVABLE |
+ __GFP_THISNODE, 0);
+}
+
+/*
+ * Migrate pages from one node to a target node.
+ * Returns error or the number of pages not migrated.
+ */
+static int migrate_to_node(struct mm_struct *mm, int source, int dest,
+ int flags)
+{
+ nodemask_t nmask;
+ LIST_HEAD(pagelist);
+ int err = 0;
+
+ nodes_clear(nmask);
+ node_set(source, nmask);
+
+ /*
+ * This does not "check" the range but isolates all pages that
+ * need migration. Between passing in the full user address
+ * space range and MPOL_MF_DISCONTIG_OK, this call can not fail.
+ */
+ VM_BUG_ON(!(flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)));
+ queue_pages_range(mm, mm->mmap->vm_start, mm->task_size, &nmask,
+ flags | MPOL_MF_DISCONTIG_OK, &pagelist);
+
+ if (!list_empty(&pagelist)) {
+ err = migrate_pages(&pagelist, alloc_new_node_page, NULL, dest,
+ MIGRATE_SYNC, MR_SYSCALL);
+ if (err)
+ putback_movable_pages(&pagelist);
+ }
+
+ return err;
+}
+
+/*
+ * Move pages between the two nodesets so as to preserve the physical
+ * layout as much as possible.
+ *
+ * Returns the number of page that could not be moved.
+ */
+int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from,
+ const nodemask_t *to, int flags)
+{
+ int busy = 0;
+ int err;
+ nodemask_t tmp;
+
+ err = migrate_prep();
+ if (err)
+ return err;
+
+ down_read(&mm->mmap_sem);
+
+ /*
+ * Find a 'source' bit set in 'tmp' whose corresponding 'dest'
+ * bit in 'to' is not also set in 'tmp'. Clear the found 'source'
+ * bit in 'tmp', and return that <source, dest> pair for migration.
+ * The pair of nodemasks 'to' and 'from' define the map.
+ *
+ * If no pair of bits is found that way, fallback to picking some
+ * pair of 'source' and 'dest' bits that are not the same. If the
+ * 'source' and 'dest' bits are the same, this represents a node
+ * that will be migrating to itself, so no pages need move.
+ *
+ * If no bits are left in 'tmp', or if all remaining bits left
+ * in 'tmp' correspond to the same bit in 'to', return false
+ * (nothing left to migrate).
+ *
+ * This lets us pick a pair of nodes to migrate between, such that
+ * if possible the dest node is not already occupied by some other
+ * source node, minimizing the risk of overloading the memory on a
+ * node that would happen if we migrated incoming memory to a node
+ * before migrating outgoing memory source that same node.
+ *
+ * A single scan of tmp is sufficient. As we go, we remember the
+ * most recent <s, d> pair that moved (s != d). If we find a pair
+ * that not only moved, but what's better, moved to an empty slot
+ * (d is not set in tmp), then we break out then, with that pair.
+ * Otherwise when we finish scanning from_tmp, we at least have the
+ * most recent <s, d> pair that moved. If we get all the way through
+ * the scan of tmp without finding any node that moved, much less
+ * moved to an empty node, then there is nothing left worth migrating.
+ */
+
+ tmp = *from;
+ while (!nodes_empty(tmp)) {
+ int s,d;
+ int source = NUMA_NO_NODE;
+ int dest = 0;
+
+ for_each_node_mask(s, tmp) {
+
+ /*
+ * do_migrate_pages() tries to maintain the relative
+ * node relationship of the pages established between
+ * threads and memory areas.
+ *
+ * However if the number of source nodes is not equal to
+ * the number of destination nodes we can not preserve
+ * this node relative relationship. In that case, skip
+ * copying memory from a node that is in the destination
+ * mask.
+ *
+ * Example: [2,3,4] -> [3,4,5] moves everything.
+ * [0-7] - > [3,4,5] moves only 0,1,2,6,7.
+ */
+
+ if ((nodes_weight(*from) != nodes_weight(*to)) &&
+ (node_isset(s, *to)))
+ continue;
+
+ d = node_remap(s, *from, *to);
+ if (s == d)
+ continue;
+
+ source = s; /* Node moved. Memorize */
+ dest = d;
+
+ /* dest not in remaining from nodes? */
+ if (!node_isset(dest, tmp))
+ break;
+ }
+ if (source == NUMA_NO_NODE)
+ break;
+
+ node_clear(source, tmp);
+ err = migrate_to_node(mm, source, dest, flags);
+ if (err > 0)
+ busy += err;
+ if (err < 0)
+ break;
+ }
+ up_read(&mm->mmap_sem);
+ if (err < 0)
+ return err;
+ return busy;
+
+}
+
+/*
+ * Allocate a new page for page migration based on vma policy.
+ * Start by assuming the page is mapped by the same vma as contains @start.
+ * Search forward from there, if not. N.B., this assumes that the
+ * list of pages handed to migrate_pages()--which is how we get here--
+ * is in virtual address order.
+ */
+static struct page *new_page(struct page *page, unsigned long start)
+{
+ struct vm_area_struct *vma;
+ unsigned long uninitialized_var(address);
+
+ vma = find_vma(current->mm, start);
+ while (vma) {
+ address = page_address_in_vma(page, vma);
+ if (address != -EFAULT)
+ break;
+ vma = vma->vm_next;
+ }
+
+ if (PageHuge(page)) {
+ return alloc_huge_page_vma(page_hstate(compound_head(page)),
+ vma, address);
+ } else if (PageTransHuge(page)) {
+ struct page *thp;
+
+ thp = alloc_hugepage_vma(GFP_TRANSHUGE, vma, address,
+ HPAGE_PMD_ORDER);
+ if (!thp)
+ return NULL;
+ prep_transhuge_page(thp);
+ return thp;
+ }
+ /*
+ * if !vma, alloc_page_vma() will use task or system default policy
+ */
+ return alloc_page_vma(GFP_HIGHUSER_MOVABLE | __GFP_RETRY_MAYFAIL,
+ vma, address);
+}
+#else
+
+static void migrate_page_add(struct page *page, struct list_head *pagelist,
+ unsigned long flags)
+{
+}
+
+int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from,
+ const nodemask_t *to, int flags)
+{
+ return -ENOSYS;
+}
+
+static struct page *new_page(struct page *page, unsigned long start)
+{
+ return NULL;
+}
+#endif
+
+static long do_mbind(unsigned long start, unsigned long len,
+ unsigned short mode, unsigned short mode_flags,
+ nodemask_t *nmask, unsigned long flags)
+{
+ struct mm_struct *mm = current->mm;
+ struct mempolicy *new;
+ unsigned long end;
+ int err;
+ LIST_HEAD(pagelist);
+
+ if (flags & ~(unsigned long)MPOL_MF_VALID)
+ return -EINVAL;
+ if ((flags & MPOL_MF_MOVE_ALL) && !capable(CAP_SYS_NICE))
+ return -EPERM;
+
+ if (start & ~PAGE_MASK)
+ return -EINVAL;
+
+ if (mode == MPOL_DEFAULT)
+ flags &= ~MPOL_MF_STRICT;
+
+ len = (len + PAGE_SIZE - 1) & PAGE_MASK;
+ end = start + len;
+
+ if (end < start)
+ return -EINVAL;
+ if (end == start)
+ return 0;
+
+ new = mpol_new(mode, mode_flags, nmask);
+ if (IS_ERR(new))
+ return PTR_ERR(new);
+
+ if (flags & MPOL_MF_LAZY)
+ new->flags |= MPOL_F_MOF;
+
+ /*
+ * If we are using the default policy then operation
+ * on discontinuous address spaces is okay after all
+ */
+ if (!new)
+ flags |= MPOL_MF_DISCONTIG_OK;
+
+ pr_debug("mbind %lx-%lx mode:%d flags:%d nodes:%lx\n",
+ start, start + len, mode, mode_flags,
+ nmask ? nodes_addr(*nmask)[0] : NUMA_NO_NODE);
+
+ if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) {
+
+ err = migrate_prep();
+ if (err)
+ goto mpol_out;
+ }
+ {
+ NODEMASK_SCRATCH(scratch);
+ if (scratch) {
+ down_write(&mm->mmap_sem);
+ task_lock(current);
+ err = mpol_set_nodemask(new, nmask, scratch);
+ task_unlock(current);
+ if (err)
+ up_write(&mm->mmap_sem);
+ } else
+ err = -ENOMEM;
+ NODEMASK_SCRATCH_FREE(scratch);
+ }
+ if (err)
+ goto mpol_out;
+
+ err = queue_pages_range(mm, start, end, nmask,
+ flags | MPOL_MF_INVERT, &pagelist);
+ if (!err)
+ err = mbind_range(mm, start, end, new);
+
+ if (!err) {
+ int nr_failed = 0;
+
+ if (!list_empty(&pagelist)) {
+ WARN_ON_ONCE(flags & MPOL_MF_LAZY);
+ nr_failed = migrate_pages(&pagelist, new_page, NULL,
+ start, MIGRATE_SYNC, MR_MEMPOLICY_MBIND);
+ if (nr_failed)
+ putback_movable_pages(&pagelist);
+ }
+
+ if (nr_failed && (flags & MPOL_MF_STRICT))
+ err = -EIO;
+ } else
+ putback_movable_pages(&pagelist);
+
+ up_write(&mm->mmap_sem);
+ mpol_out:
+ mpol_put(new);
+ return err;
+}
+
+/*
+ * User space interface with variable sized bitmaps for nodelists.
+ */
+
+/* Copy a node mask from user space. */
+static int get_nodes(nodemask_t *nodes, const unsigned long __user *nmask,
+ unsigned long maxnode)
+{
+ unsigned long k;
+ unsigned long t;
+ unsigned long nlongs;
+ unsigned long endmask;
+
+ --maxnode;
+ nodes_clear(*nodes);
+ if (maxnode == 0 || !nmask)
+ return 0;
+ if (maxnode > PAGE_SIZE*BITS_PER_BYTE)
+ return -EINVAL;
+
+ nlongs = BITS_TO_LONGS(maxnode);
+ if ((maxnode % BITS_PER_LONG) == 0)
+ endmask = ~0UL;
+ else
+ endmask = (1UL << (maxnode % BITS_PER_LONG)) - 1;
+
+ /*
+ * When the user specified more nodes than supported just check
+ * if the non supported part is all zero.
+ *
+ * If maxnode have more longs than MAX_NUMNODES, check
+ * the bits in that area first. And then go through to
+ * check the rest bits which equal or bigger than MAX_NUMNODES.
+ * Otherwise, just check bits [MAX_NUMNODES, maxnode).
+ */
+ if (nlongs > BITS_TO_LONGS(MAX_NUMNODES)) {
+ for (k = BITS_TO_LONGS(MAX_NUMNODES); k < nlongs; k++) {
+ if (get_user(t, nmask + k))
+ return -EFAULT;
+ if (k == nlongs - 1) {
+ if (t & endmask)
+ return -EINVAL;
+ } else if (t)
+ return -EINVAL;
+ }
+ nlongs = BITS_TO_LONGS(MAX_NUMNODES);
+ endmask = ~0UL;
+ }
+
+ if (maxnode > MAX_NUMNODES && MAX_NUMNODES % BITS_PER_LONG != 0) {
+ unsigned long valid_mask = endmask;
+
+ valid_mask &= ~((1UL << (MAX_NUMNODES % BITS_PER_LONG)) - 1);
+ if (get_user(t, nmask + nlongs - 1))
+ return -EFAULT;
+ if (t & valid_mask)
+ return -EINVAL;
+ }
+
+ if (copy_from_user(nodes_addr(*nodes), nmask, nlongs*sizeof(unsigned long)))
+ return -EFAULT;
+ nodes_addr(*nodes)[nlongs-1] &= endmask;
+ return 0;
+}
+
+/* Copy a kernel node mask to user space */
+static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode,
+ nodemask_t *nodes)
+{
+ unsigned long copy = ALIGN(maxnode-1, 64) / 8;
+ const int nbytes = BITS_TO_LONGS(MAX_NUMNODES) * sizeof(long);
+
+ if (copy > nbytes) {
+ if (copy > PAGE_SIZE)
+ return -EINVAL;
+ if (clear_user((char __user *)mask + nbytes, copy - nbytes))
+ return -EFAULT;
+ copy = nbytes;
+ }
+ return copy_to_user(mask, nodes_addr(*nodes), copy) ? -EFAULT : 0;
+}
+
+static long kernel_mbind(unsigned long start, unsigned long len,
+ unsigned long mode, const unsigned long __user *nmask,
+ unsigned long maxnode, unsigned int flags)
+{
+ nodemask_t nodes;
+ int err;
+ unsigned short mode_flags;
+
+ mode_flags = mode & MPOL_MODE_FLAGS;
+ mode &= ~MPOL_MODE_FLAGS;
+ if (mode >= MPOL_MAX)
+ return -EINVAL;
+ if ((mode_flags & MPOL_F_STATIC_NODES) &&
+ (mode_flags & MPOL_F_RELATIVE_NODES))
+ return -EINVAL;
+ err = get_nodes(&nodes, nmask, maxnode);
+ if (err)
+ return err;
+ return do_mbind(start, len, mode, mode_flags, &nodes, flags);
+}
+
+SYSCALL_DEFINE6(mbind, unsigned long, start, unsigned long, len,
+ unsigned long, mode, const unsigned long __user *, nmask,
+ unsigned long, maxnode, unsigned int, flags)
+{
+ return kernel_mbind(start, len, mode, nmask, maxnode, flags);
+}
+
+/* Set the process memory policy */
+static long kernel_set_mempolicy(int mode, const unsigned long __user *nmask,
+ unsigned long maxnode)
+{
+ int err;
+ nodemask_t nodes;
+ unsigned short flags;
+
+ flags = mode & MPOL_MODE_FLAGS;
+ mode &= ~MPOL_MODE_FLAGS;
+ if ((unsigned int)mode >= MPOL_MAX)
+ return -EINVAL;
+ if ((flags & MPOL_F_STATIC_NODES) && (flags & MPOL_F_RELATIVE_NODES))
+ return -EINVAL;
+ err = get_nodes(&nodes, nmask, maxnode);
+ if (err)
+ return err;
+ return do_set_mempolicy(mode, flags, &nodes);
+}
+
+SYSCALL_DEFINE3(set_mempolicy, int, mode, const unsigned long __user *, nmask,
+ unsigned long, maxnode)
+{
+ return kernel_set_mempolicy(mode, nmask, maxnode);
+}
+
+static int kernel_migrate_pages(pid_t pid, unsigned long maxnode,
+ const unsigned long __user *old_nodes,
+ const unsigned long __user *new_nodes)
+{
+ struct mm_struct *mm = NULL;
+ struct task_struct *task;
+ nodemask_t task_nodes;
+ int err;
+ nodemask_t *old;
+ nodemask_t *new;
+ NODEMASK_SCRATCH(scratch);
+
+ if (!scratch)
+ return -ENOMEM;
+
+ old = &scratch->mask1;
+ new = &scratch->mask2;
+
+ err = get_nodes(old, old_nodes, maxnode);
+ if (err)
+ goto out;
+
+ err = get_nodes(new, new_nodes, maxnode);
+ if (err)
+ goto out;
+
+ /* Find the mm_struct */
+ rcu_read_lock();
+ task = pid ? find_task_by_vpid(pid) : current;
+ if (!task) {
+ rcu_read_unlock();
+ err = -ESRCH;
+ goto out;
+ }
+ get_task_struct(task);
+
+ err = -EINVAL;
+
+ /*
+ * Check if this process has the right to modify the specified process.
+ * Use the regular "ptrace_may_access()" checks.
+ */
+ if (!ptrace_may_access(task, PTRACE_MODE_READ_REALCREDS)) {
+ rcu_read_unlock();
+ err = -EPERM;
+ goto out_put;
+ }
+ rcu_read_unlock();
+
+ task_nodes = cpuset_mems_allowed(task);
+ /* Is the user allowed to access the target nodes? */
+ if (!nodes_subset(*new, task_nodes) && !capable(CAP_SYS_NICE)) {
+ err = -EPERM;
+ goto out_put;
+ }
+
+ task_nodes = cpuset_mems_allowed(current);
+ nodes_and(*new, *new, task_nodes);
+ if (nodes_empty(*new))
+ goto out_put;
+
+ nodes_and(*new, *new, node_states[N_MEMORY]);
+ if (nodes_empty(*new))
+ goto out_put;
+
+ err = security_task_movememory(task);
+ if (err)
+ goto out_put;
+
+ mm = get_task_mm(task);
+ put_task_struct(task);
+
+ if (!mm) {
+ err = -EINVAL;
+ goto out;
+ }
+
+ err = do_migrate_pages(mm, old, new,
+ capable(CAP_SYS_NICE) ? MPOL_MF_MOVE_ALL : MPOL_MF_MOVE);
+
+ mmput(mm);
+out:
+ NODEMASK_SCRATCH_FREE(scratch);
+
+ return err;
+
+out_put:
+ put_task_struct(task);
+ goto out;
+
+}
+
+SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode,
+ const unsigned long __user *, old_nodes,
+ const unsigned long __user *, new_nodes)
+{
+ return kernel_migrate_pages(pid, maxnode, old_nodes, new_nodes);
+}
+
+
+/* Retrieve NUMA policy */
+static int kernel_get_mempolicy(int __user *policy,
+ unsigned long __user *nmask,
+ unsigned long maxnode,
+ unsigned long addr,
+ unsigned long flags)
+{
+ int err;
+ int uninitialized_var(pval);
+ nodemask_t nodes;
+
+ if (nmask != NULL && maxnode < MAX_NUMNODES)
+ return -EINVAL;
+
+ err = do_get_mempolicy(&pval, &nodes, addr, flags);
+
+ if (err)
+ return err;
+
+ if (policy && put_user(pval, policy))
+ return -EFAULT;
+
+ if (nmask)
+ err = copy_nodes_to_user(nmask, maxnode, &nodes);
+
+ return err;
+}
+
+SYSCALL_DEFINE5(get_mempolicy, int __user *, policy,
+ unsigned long __user *, nmask, unsigned long, maxnode,
+ unsigned long, addr, unsigned long, flags)
+{
+ return kernel_get_mempolicy(policy, nmask, maxnode, addr, flags);
+}
+
+#ifdef CONFIG_COMPAT
+
+COMPAT_SYSCALL_DEFINE5(get_mempolicy, int __user *, policy,
+ compat_ulong_t __user *, nmask,
+ compat_ulong_t, maxnode,
+ compat_ulong_t, addr, compat_ulong_t, flags)
+{
+ long err;
+ unsigned long __user *nm = NULL;
+ unsigned long nr_bits, alloc_size;
+ DECLARE_BITMAP(bm, MAX_NUMNODES);
+
+ nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES);
+ alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
+
+ if (nmask)
+ nm = compat_alloc_user_space(alloc_size);
+
+ err = kernel_get_mempolicy(policy, nm, nr_bits+1, addr, flags);
+
+ if (!err && nmask) {
+ unsigned long copy_size;
+ copy_size = min_t(unsigned long, sizeof(bm), alloc_size);
+ err = copy_from_user(bm, nm, copy_size);
+ /* ensure entire bitmap is zeroed */
+ err |= clear_user(nmask, ALIGN(maxnode-1, 8) / 8);
+ err |= compat_put_bitmap(nmask, bm, nr_bits);
+ }
+
+ return err;
+}
+
+COMPAT_SYSCALL_DEFINE3(set_mempolicy, int, mode, compat_ulong_t __user *, nmask,
+ compat_ulong_t, maxnode)
+{
+ unsigned long __user *nm = NULL;
+ unsigned long nr_bits, alloc_size;
+ DECLARE_BITMAP(bm, MAX_NUMNODES);
+
+ nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES);
+ alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
+
+ if (nmask) {
+ if (compat_get_bitmap(bm, nmask, nr_bits))
+ return -EFAULT;
+ nm = compat_alloc_user_space(alloc_size);
+ if (copy_to_user(nm, bm, alloc_size))
+ return -EFAULT;
+ }
+
+ return kernel_set_mempolicy(mode, nm, nr_bits+1);
+}
+
+COMPAT_SYSCALL_DEFINE6(mbind, compat_ulong_t, start, compat_ulong_t, len,
+ compat_ulong_t, mode, compat_ulong_t __user *, nmask,
+ compat_ulong_t, maxnode, compat_ulong_t, flags)
+{
+ unsigned long __user *nm = NULL;
+ unsigned long nr_bits, alloc_size;
+ nodemask_t bm;
+
+ nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES);
+ alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
+
+ if (nmask) {
+ if (compat_get_bitmap(nodes_addr(bm), nmask, nr_bits))
+ return -EFAULT;
+ nm = compat_alloc_user_space(alloc_size);
+ if (copy_to_user(nm, nodes_addr(bm), alloc_size))
+ return -EFAULT;
+ }
+
+ return kernel_mbind(start, len, mode, nm, nr_bits+1, flags);
+}
+
+COMPAT_SYSCALL_DEFINE4(migrate_pages, compat_pid_t, pid,
+ compat_ulong_t, maxnode,
+ const compat_ulong_t __user *, old_nodes,
+ const compat_ulong_t __user *, new_nodes)
+{
+ unsigned long __user *old = NULL;
+ unsigned long __user *new = NULL;
+ nodemask_t tmp_mask;
+ unsigned long nr_bits;
+ unsigned long size;
+
+ nr_bits = min_t(unsigned long, maxnode - 1, MAX_NUMNODES);
+ size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
+ if (old_nodes) {
+ if (compat_get_bitmap(nodes_addr(tmp_mask), old_nodes, nr_bits))
+ return -EFAULT;
+ old = compat_alloc_user_space(new_nodes ? size * 2 : size);
+ if (new_nodes)
+ new = old + size / sizeof(unsigned long);
+ if (copy_to_user(old, nodes_addr(tmp_mask), size))
+ return -EFAULT;
+ }
+ if (new_nodes) {
+ if (compat_get_bitmap(nodes_addr(tmp_mask), new_nodes, nr_bits))
+ return -EFAULT;
+ if (new == NULL)
+ new = compat_alloc_user_space(size);
+ if (copy_to_user(new, nodes_addr(tmp_mask), size))
+ return -EFAULT;
+ }
+ return kernel_migrate_pages(pid, nr_bits + 1, old, new);
+}
+
+#endif /* CONFIG_COMPAT */
+
+struct mempolicy *__get_vma_policy(struct vm_area_struct *vma,
+ unsigned long addr)
+{
+ struct mempolicy *pol = NULL;
+
+ if (vma) {
+ if (vma->vm_ops && vma->vm_ops->get_policy) {
+ pol = vma->vm_ops->get_policy(vma, addr);
+ } else if (vma->vm_policy) {
+ pol = vma->vm_policy;
+
+ /*
+ * shmem_alloc_page() passes MPOL_F_SHARED policy with
+ * a pseudo vma whose vma->vm_ops=NULL. Take a reference
+ * count on these policies which will be dropped by
+ * mpol_cond_put() later
+ */
+ if (mpol_needs_cond_ref(pol))
+ mpol_get(pol);
+ }
+ }
+
+ return pol;
+}
+
+/*
+ * get_vma_policy(@vma, @addr)
+ * @vma: virtual memory area whose policy is sought
+ * @addr: address in @vma for shared policy lookup
+ *
+ * Returns effective policy for a VMA at specified address.
+ * Falls back to current->mempolicy or system default policy, as necessary.
+ * Shared policies [those marked as MPOL_F_SHARED] require an extra reference
+ * count--added by the get_policy() vm_op, as appropriate--to protect against
+ * freeing by another task. It is the caller's responsibility to free the
+ * extra reference for shared policies.
+ */
+static struct mempolicy *get_vma_policy(struct vm_area_struct *vma,
+ unsigned long addr)
+{
+ struct mempolicy *pol = __get_vma_policy(vma, addr);
+
+ if (!pol)
+ pol = get_task_policy(current);
+
+ return pol;
+}
+
+bool vma_policy_mof(struct vm_area_struct *vma)
+{
+ struct mempolicy *pol;
+
+ if (vma->vm_ops && vma->vm_ops->get_policy) {
+ bool ret = false;
+
+ pol = vma->vm_ops->get_policy(vma, vma->vm_start);
+ if (pol && (pol->flags & MPOL_F_MOF))
+ ret = true;
+ mpol_cond_put(pol);
+
+ return ret;
+ }
+
+ pol = vma->vm_policy;
+ if (!pol)
+ pol = get_task_policy(current);
+
+ return pol->flags & MPOL_F_MOF;
+}
+
+static int apply_policy_zone(struct mempolicy *policy, enum zone_type zone)
+{
+ enum zone_type dynamic_policy_zone = policy_zone;
+
+ BUG_ON(dynamic_policy_zone == ZONE_MOVABLE);
+
+ /*
+ * if policy->v.nodes has movable memory only,
+ * we apply policy when gfp_zone(gfp) = ZONE_MOVABLE only.
+ *
+ * policy->v.nodes is intersect with node_states[N_MEMORY].
+ * so if the following test faile, it implies
+ * policy->v.nodes has movable memory only.
+ */
+ if (!nodes_intersects(policy->v.nodes, node_states[N_HIGH_MEMORY]))
+ dynamic_policy_zone = ZONE_MOVABLE;
+
+ return zone >= dynamic_policy_zone;
+}
+
+/*
+ * Return a nodemask representing a mempolicy for filtering nodes for
+ * page allocation
+ */
+static nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *policy)
+{
+ /* Lower zones don't get a nodemask applied for MPOL_BIND */
+ if (unlikely(policy->mode == MPOL_BIND) &&
+ apply_policy_zone(policy, gfp_zone(gfp)) &&
+ cpuset_nodemask_valid_mems_allowed(&policy->v.nodes))
+ return &policy->v.nodes;
+
+ return NULL;
+}
+
+/* Return the node id preferred by the given mempolicy, or the given id */
+static int policy_node(gfp_t gfp, struct mempolicy *policy,
+ int nd)
+{
+ if (policy->mode == MPOL_PREFERRED && !(policy->flags & MPOL_F_LOCAL))
+ nd = policy->v.preferred_node;
+ else {
+ /*
+ * __GFP_THISNODE shouldn't even be used with the bind policy
+ * because we might easily break the expectation to stay on the
+ * requested node and not break the policy.
+ */
+ WARN_ON_ONCE(policy->mode == MPOL_BIND && (gfp & __GFP_THISNODE));
+ }
+
+ return nd;
+}
+
+/* Do dynamic interleaving for a process */
+static unsigned interleave_nodes(struct mempolicy *policy)
+{
+ unsigned next;
+ struct task_struct *me = current;
+
+ next = next_node_in(me->il_prev, policy->v.nodes);
+ if (next < MAX_NUMNODES)
+ me->il_prev = next;
+ return next;
+}
+
+/*
+ * Depending on the memory policy provide a node from which to allocate the
+ * next slab entry.
+ */
+unsigned int mempolicy_slab_node(void)
+{
+ struct mempolicy *policy;
+ int node = numa_mem_id();
+
+ if (in_interrupt())
+ return node;
+
+ policy = current->mempolicy;
+ if (!policy || policy->flags & MPOL_F_LOCAL)
+ return node;
+
+ switch (policy->mode) {
+ case MPOL_PREFERRED:
+ /*
+ * handled MPOL_F_LOCAL above
+ */
+ return policy->v.preferred_node;
+
+ case MPOL_INTERLEAVE:
+ return interleave_nodes(policy);
+
+ case MPOL_BIND: {
+ struct zoneref *z;
+
+ /*
+ * Follow bind policy behavior and start allocation at the
+ * first node.
+ */
+ struct zonelist *zonelist;
+ enum zone_type highest_zoneidx = gfp_zone(GFP_KERNEL);
+ zonelist = &NODE_DATA(node)->node_zonelists[ZONELIST_FALLBACK];
+ z = first_zones_zonelist(zonelist, highest_zoneidx,
+ &policy->v.nodes);
+ return z->zone ? zone_to_nid(z->zone) : node;
+ }
+
+ default:
+ BUG();
+ }
+}
+
+/*
+ * Do static interleaving for a VMA with known offset @n. Returns the n'th
+ * node in pol->v.nodes (starting from n=0), wrapping around if n exceeds the
+ * number of present nodes.
+ */
+static unsigned offset_il_node(struct mempolicy *pol, unsigned long n)
+{
+ unsigned nnodes = nodes_weight(pol->v.nodes);
+ unsigned target;
+ int i;
+ int nid;
+
+ if (!nnodes)
+ return numa_node_id();
+ target = (unsigned int)n % nnodes;
+ nid = first_node(pol->v.nodes);
+ for (i = 0; i < target; i++)
+ nid = next_node(nid, pol->v.nodes);
+ return nid;
+}
+
+/* Determine a node number for interleave */
+static inline unsigned interleave_nid(struct mempolicy *pol,
+ struct vm_area_struct *vma, unsigned long addr, int shift)
+{
+ if (vma) {
+ unsigned long off;
+
+ /*
+ * for small pages, there is no difference between
+ * shift and PAGE_SHIFT, so the bit-shift is safe.
+ * for huge pages, since vm_pgoff is in units of small
+ * pages, we need to shift off the always 0 bits to get
+ * a useful offset.
+ */
+ BUG_ON(shift < PAGE_SHIFT);
+ off = vma->vm_pgoff >> (shift - PAGE_SHIFT);
+ off += (addr - vma->vm_start) >> shift;
+ return offset_il_node(pol, off);
+ } else
+ return interleave_nodes(pol);
+}
+
+#ifdef CONFIG_HUGETLBFS
+/*
+ * huge_node(@vma, @addr, @gfp_flags, @mpol)
+ * @vma: virtual memory area whose policy is sought
+ * @addr: address in @vma for shared policy lookup and interleave policy
+ * @gfp_flags: for requested zone
+ * @mpol: pointer to mempolicy pointer for reference counted mempolicy
+ * @nodemask: pointer to nodemask pointer for MPOL_BIND nodemask
+ *
+ * Returns a nid suitable for a huge page allocation and a pointer
+ * to the struct mempolicy for conditional unref after allocation.
+ * If the effective policy is 'BIND, returns a pointer to the mempolicy's
+ * @nodemask for filtering the zonelist.
+ *
+ * Must be protected by read_mems_allowed_begin()
+ */
+int huge_node(struct vm_area_struct *vma, unsigned long addr, gfp_t gfp_flags,
+ struct mempolicy **mpol, nodemask_t **nodemask)
+{
+ int nid;
+
+ *mpol = get_vma_policy(vma, addr);
+ *nodemask = NULL; /* assume !MPOL_BIND */
+
+ if (unlikely((*mpol)->mode == MPOL_INTERLEAVE)) {
+ nid = interleave_nid(*mpol, vma, addr,
+ huge_page_shift(hstate_vma(vma)));
+ } else {
+ nid = policy_node(gfp_flags, *mpol, numa_node_id());
+ if ((*mpol)->mode == MPOL_BIND)
+ *nodemask = &(*mpol)->v.nodes;
+ }
+ return nid;
+}
+
+/*
+ * init_nodemask_of_mempolicy
+ *
+ * If the current task's mempolicy is "default" [NULL], return 'false'
+ * to indicate default policy. Otherwise, extract the policy nodemask
+ * for 'bind' or 'interleave' policy into the argument nodemask, or
+ * initialize the argument nodemask to contain the single node for
+ * 'preferred' or 'local' policy and return 'true' to indicate presence
+ * of non-default mempolicy.
+ *
+ * We don't bother with reference counting the mempolicy [mpol_get/put]
+ * because the current task is examining it's own mempolicy and a task's
+ * mempolicy is only ever changed by the task itself.
+ *
+ * N.B., it is the caller's responsibility to free a returned nodemask.
+ */
+bool init_nodemask_of_mempolicy(nodemask_t *mask)
+{
+ struct mempolicy *mempolicy;
+ int nid;
+
+ if (!(mask && current->mempolicy))
+ return false;
+
+ task_lock(current);
+ mempolicy = current->mempolicy;
+ switch (mempolicy->mode) {
+ case MPOL_PREFERRED:
+ if (mempolicy->flags & MPOL_F_LOCAL)
+ nid = numa_node_id();
+ else
+ nid = mempolicy->v.preferred_node;
+ init_nodemask_of_node(mask, nid);
+ break;
+
+ case MPOL_BIND:
+ /* Fall through */
+ case MPOL_INTERLEAVE:
+ *mask = mempolicy->v.nodes;
+ break;
+
+ default:
+ BUG();
+ }
+ task_unlock(current);
+
+ return true;
+}
+#endif
+
+/*
+ * mempolicy_nodemask_intersects
+ *
+ * If tsk's mempolicy is "default" [NULL], return 'true' to indicate default
+ * policy. Otherwise, check for intersection between mask and the policy
+ * nodemask for 'bind' or 'interleave' policy. For 'perferred' or 'local'
+ * policy, always return true since it may allocate elsewhere on fallback.
+ *
+ * Takes task_lock(tsk) to prevent freeing of its mempolicy.
+ */
+bool mempolicy_nodemask_intersects(struct task_struct *tsk,
+ const nodemask_t *mask)
+{
+ struct mempolicy *mempolicy;
+ bool ret = true;
+
+ if (!mask)
+ return ret;
+ task_lock(tsk);
+ mempolicy = tsk->mempolicy;
+ if (!mempolicy)
+ goto out;
+
+ switch (mempolicy->mode) {
+ case MPOL_PREFERRED:
+ /*
+ * MPOL_PREFERRED and MPOL_F_LOCAL are only preferred nodes to
+ * allocate from, they may fallback to other nodes when oom.
+ * Thus, it's possible for tsk to have allocated memory from
+ * nodes in mask.
+ */
+ break;
+ case MPOL_BIND:
+ case MPOL_INTERLEAVE:
+ ret = nodes_intersects(mempolicy->v.nodes, *mask);
+ break;
+ default:
+ BUG();
+ }
+out:
+ task_unlock(tsk);
+ return ret;
+}
+
+/* Allocate a page in interleaved policy.
+ Own path because it needs to do special accounting. */
+static struct page *alloc_page_interleave(gfp_t gfp, unsigned order,
+ unsigned nid)
+{
+ struct page *page;
+
+ page = __alloc_pages(gfp, order, nid);
+ /* skip NUMA_INTERLEAVE_HIT counter update if numa stats is disabled */
+ if (!static_branch_likely(&vm_numa_stat_key))
+ return page;
+ if (page && page_to_nid(page) == nid) {
+ preempt_disable();
+ __inc_numa_state(page_zone(page), NUMA_INTERLEAVE_HIT);
+ preempt_enable();
+ }
+ return page;
+}
+
+/**
+ * alloc_pages_vma - Allocate a page for a VMA.
+ *
+ * @gfp:
+ * %GFP_USER user allocation.
+ * %GFP_KERNEL kernel allocations,
+ * %GFP_HIGHMEM highmem/user allocations,
+ * %GFP_FS allocation should not call back into a file system.
+ * %GFP_ATOMIC don't sleep.
+ *
+ * @order:Order of the GFP allocation.
+ * @vma: Pointer to VMA or NULL if not available.
+ * @addr: Virtual Address of the allocation. Must be inside the VMA.
+ * @node: Which node to prefer for allocation (modulo policy).
+ * @hugepage: for hugepages try only the preferred node if possible
+ *
+ * This function allocates a page from the kernel page pool and applies
+ * a NUMA policy associated with the VMA or the current process.
+ * When VMA is not NULL caller must hold down_read on the mmap_sem of the
+ * mm_struct of the VMA to prevent it from going away. Should be used for
+ * all allocations for pages that will be mapped into user space. Returns
+ * NULL when no page can be allocated.
+ */
+struct page *
+alloc_pages_vma(gfp_t gfp, int order, struct vm_area_struct *vma,
+ unsigned long addr, int node, bool hugepage)
+{
+ struct mempolicy *pol;
+ struct page *page;
+ int preferred_nid;
+ nodemask_t *nmask;
+
+ pol = get_vma_policy(vma, addr);
+
+ if (pol->mode == MPOL_INTERLEAVE) {
+ unsigned nid;
+
+ nid = interleave_nid(pol, vma, addr, PAGE_SHIFT + order);
+ mpol_cond_put(pol);
+ page = alloc_page_interleave(gfp, order, nid);
+ goto out;
+ }
+
+ if (unlikely(IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && hugepage)) {
+ int hpage_node = node;
+
+ /*
+ * For hugepage allocation and non-interleave policy which
+ * allows the current node (or other explicitly preferred
+ * node) we only try to allocate from the current/preferred
+ * node and don't fall back to other nodes, as the cost of
+ * remote accesses would likely offset THP benefits.
+ *
+ * If the policy is interleave, or does not allow the current
+ * node in its nodemask, we allocate the standard way.
+ */
+ if (pol->mode == MPOL_PREFERRED &&
+ !(pol->flags & MPOL_F_LOCAL))
+ hpage_node = pol->v.preferred_node;
+
+ nmask = policy_nodemask(gfp, pol);
+ if (!nmask || node_isset(hpage_node, *nmask)) {
+ mpol_cond_put(pol);
+ /*
+ * We cannot invoke reclaim if __GFP_THISNODE
+ * is set. Invoking reclaim with
+ * __GFP_THISNODE set, would cause THP
+ * allocations to trigger heavy swapping
+ * despite there may be tons of free memory
+ * (including potentially plenty of THP
+ * already available in the buddy) on all the
+ * other NUMA nodes.
+ *
+ * At most we could invoke compaction when
+ * __GFP_THISNODE is set (but we would need to
+ * refrain from invoking reclaim even if
+ * compaction returned COMPACT_SKIPPED because
+ * there wasn't not enough memory to succeed
+ * compaction). For now just avoid
+ * __GFP_THISNODE instead of limiting the
+ * allocation path to a strict and single
+ * compaction invocation.
+ *
+ * Supposedly if direct reclaim was enabled by
+ * the caller, the app prefers THP regardless
+ * of the node it comes from so this would be
+ * more desiderable behavior than only
+ * providing THP originated from the local
+ * node in such case.
+ */
+ if (!(gfp & __GFP_DIRECT_RECLAIM))
+ gfp |= __GFP_THISNODE;
+ page = __alloc_pages_node(hpage_node, gfp, order);
+ goto out;
+ }
+ }
+
+ nmask = policy_nodemask(gfp, pol);
+ preferred_nid = policy_node(gfp, pol, node);
+ page = __alloc_pages_nodemask(gfp, order, preferred_nid, nmask);
+ mpol_cond_put(pol);
+out:
+ return page;
+}
+
+/**
+ * alloc_pages_current - Allocate pages.
+ *
+ * @gfp:
+ * %GFP_USER user allocation,
+ * %GFP_KERNEL kernel allocation,
+ * %GFP_HIGHMEM highmem allocation,
+ * %GFP_FS don't call back into a file system.
+ * %GFP_ATOMIC don't sleep.
+ * @order: Power of two of allocation size in pages. 0 is a single page.
+ *
+ * Allocate a page from the kernel page pool. When not in
+ * interrupt context and apply the current process NUMA policy.
+ * Returns NULL when no page can be allocated.
+ */
+struct page *alloc_pages_current(gfp_t gfp, unsigned order)
+{
+ struct mempolicy *pol = &default_policy;
+ struct page *page;
+
+ if (!in_interrupt() && !(gfp & __GFP_THISNODE))
+ pol = get_task_policy(current);
+
+ /*
+ * No reference counting needed for current->mempolicy
+ * nor system default_policy
+ */
+ if (pol->mode == MPOL_INTERLEAVE)
+ page = alloc_page_interleave(gfp, order, interleave_nodes(pol));
+ else
+ page = __alloc_pages_nodemask(gfp, order,
+ policy_node(gfp, pol, numa_node_id()),
+ policy_nodemask(gfp, pol));
+
+ return page;
+}
+EXPORT_SYMBOL(alloc_pages_current);
+
+int vma_dup_policy(struct vm_area_struct *src, struct vm_area_struct *dst)
+{
+ struct mempolicy *pol = mpol_dup(vma_policy(src));
+
+ if (IS_ERR(pol))
+ return PTR_ERR(pol);
+ dst->vm_policy = pol;
+ return 0;
+}
+
+/*
+ * If mpol_dup() sees current->cpuset == cpuset_being_rebound, then it
+ * rebinds the mempolicy its copying by calling mpol_rebind_policy()
+ * with the mems_allowed returned by cpuset_mems_allowed(). This
+ * keeps mempolicies cpuset relative after its cpuset moves. See
+ * further kernel/cpuset.c update_nodemask().
+ *
+ * current's mempolicy may be rebinded by the other task(the task that changes
+ * cpuset's mems), so we needn't do rebind work for current task.
+ */
+
+/* Slow path of a mempolicy duplicate */
+struct mempolicy *__mpol_dup(struct mempolicy *old)
+{
+ struct mempolicy *new = kmem_cache_alloc(policy_cache, GFP_KERNEL);
+
+ if (!new)
+ return ERR_PTR(-ENOMEM);
+
+ /* task's mempolicy is protected by alloc_lock */
+ if (old == current->mempolicy) {
+ task_lock(current);
+ *new = *old;
+ task_unlock(current);
+ } else
+ *new = *old;
+
+ if (current_cpuset_is_being_rebound()) {
+ nodemask_t mems = cpuset_mems_allowed(current);
+ mpol_rebind_policy(new, &mems);
+ }
+ atomic_set(&new->refcnt, 1);
+ return new;
+}
+
+/* Slow path of a mempolicy comparison */
+bool __mpol_equal(struct mempolicy *a, struct mempolicy *b)
+{
+ if (!a || !b)
+ return false;
+ if (a->mode != b->mode)
+ return false;
+ if (a->flags != b->flags)
+ return false;
+ if (mpol_store_user_nodemask(a))
+ if (!nodes_equal(a->w.user_nodemask, b->w.user_nodemask))
+ return false;
+
+ switch (a->mode) {
+ case MPOL_BIND:
+ /* Fall through */
+ case MPOL_INTERLEAVE:
+ return !!nodes_equal(a->v.nodes, b->v.nodes);
+ case MPOL_PREFERRED:
+ /* a's ->flags is the same as b's */
+ if (a->flags & MPOL_F_LOCAL)
+ return true;
+ return a->v.preferred_node == b->v.preferred_node;
+ default:
+ BUG();
+ return false;
+ }
+}
+
+/*
+ * Shared memory backing store policy support.
+ *
+ * Remember policies even when nobody has shared memory mapped.
+ * The policies are kept in Red-Black tree linked from the inode.
+ * They are protected by the sp->lock rwlock, which should be held
+ * for any accesses to the tree.
+ */
+
+/*
+ * lookup first element intersecting start-end. Caller holds sp->lock for
+ * reading or for writing
+ */
+static struct sp_node *
+sp_lookup(struct shared_policy *sp, unsigned long start, unsigned long end)
+{
+ struct rb_node *n = sp->root.rb_node;
+
+ while (n) {
+ struct sp_node *p = rb_entry(n, struct sp_node, nd);
+
+ if (start >= p->end)
+ n = n->rb_right;
+ else if (end <= p->start)
+ n = n->rb_left;
+ else
+ break;
+ }
+ if (!n)
+ return NULL;
+ for (;;) {
+ struct sp_node *w = NULL;
+ struct rb_node *prev = rb_prev(n);
+ if (!prev)
+ break;
+ w = rb_entry(prev, struct sp_node, nd);
+ if (w->end <= start)
+ break;
+ n = prev;
+ }
+ return rb_entry(n, struct sp_node, nd);
+}
+
+/*
+ * Insert a new shared policy into the list. Caller holds sp->lock for
+ * writing.
+ */
+static void sp_insert(struct shared_policy *sp, struct sp_node *new)
+{
+ struct rb_node **p = &sp->root.rb_node;
+ struct rb_node *parent = NULL;
+ struct sp_node *nd;
+
+ while (*p) {
+ parent = *p;
+ nd = rb_entry(parent, struct sp_node, nd);
+ if (new->start < nd->start)
+ p = &(*p)->rb_left;
+ else if (new->end > nd->end)
+ p = &(*p)->rb_right;
+ else
+ BUG();
+ }
+ rb_link_node(&new->nd, parent, p);
+ rb_insert_color(&new->nd, &sp->root);
+ pr_debug("inserting %lx-%lx: %d\n", new->start, new->end,
+ new->policy ? new->policy->mode : 0);
+}
+
+/* Find shared policy intersecting idx */
+struct mempolicy *
+mpol_shared_policy_lookup(struct shared_policy *sp, unsigned long idx)
+{
+ struct mempolicy *pol = NULL;
+ struct sp_node *sn;
+
+ if (!sp->root.rb_node)
+ return NULL;
+ read_lock(&sp->lock);
+ sn = sp_lookup(sp, idx, idx+1);
+ if (sn) {
+ mpol_get(sn->policy);
+ pol = sn->policy;
+ }
+ read_unlock(&sp->lock);
+ return pol;
+}
+
+static void sp_free(struct sp_node *n)
+{
+ mpol_put(n->policy);
+ kmem_cache_free(sn_cache, n);
+}
+
+/**
+ * mpol_misplaced - check whether current page node is valid in policy
+ *
+ * @page: page to be checked
+ * @vma: vm area where page mapped
+ * @addr: virtual address where page mapped
+ *
+ * Lookup current policy node id for vma,addr and "compare to" page's
+ * node id.
+ *
+ * Returns:
+ * -1 - not misplaced, page is in the right node
+ * node - node id where the page should be
+ *
+ * Policy determination "mimics" alloc_page_vma().
+ * Called from fault path where we know the vma and faulting address.
+ */
+int mpol_misplaced(struct page *page, struct vm_area_struct *vma, unsigned long addr)
+{
+ struct mempolicy *pol;
+ struct zoneref *z;
+ int curnid = page_to_nid(page);
+ unsigned long pgoff;
+ int thiscpu = raw_smp_processor_id();
+ int thisnid = cpu_to_node(thiscpu);
+ int polnid = -1;
+ int ret = -1;
+
+ pol = get_vma_policy(vma, addr);
+ if (!(pol->flags & MPOL_F_MOF))
+ goto out;
+
+ switch (pol->mode) {
+ case MPOL_INTERLEAVE:
+ pgoff = vma->vm_pgoff;
+ pgoff += (addr - vma->vm_start) >> PAGE_SHIFT;
+ polnid = offset_il_node(pol, pgoff);
+ break;
+
+ case MPOL_PREFERRED:
+ if (pol->flags & MPOL_F_LOCAL)
+ polnid = numa_node_id();
+ else
+ polnid = pol->v.preferred_node;
+ break;
+
+ case MPOL_BIND:
+
+ /*
+ * allows binding to multiple nodes.
+ * use current page if in policy nodemask,
+ * else select nearest allowed node, if any.
+ * If no allowed nodes, use current [!misplaced].
+ */
+ if (node_isset(curnid, pol->v.nodes))
+ goto out;
+ z = first_zones_zonelist(
+ node_zonelist(numa_node_id(), GFP_HIGHUSER),
+ gfp_zone(GFP_HIGHUSER),
+ &pol->v.nodes);
+ polnid = zone_to_nid(z->zone);
+ break;
+
+ default:
+ BUG();
+ }
+
+ /* Migrate the page towards the node whose CPU is referencing it */
+ if (pol->flags & MPOL_F_MORON) {
+ polnid = thisnid;
+
+ if (!should_numa_migrate_memory(current, page, curnid, thiscpu))
+ goto out;
+ }
+
+ if (curnid != polnid)
+ ret = polnid;
+out:
+ mpol_cond_put(pol);
+
+ return ret;
+}
+
+/*
+ * Drop the (possibly final) reference to task->mempolicy. It needs to be
+ * dropped after task->mempolicy is set to NULL so that any allocation done as
+ * part of its kmem_cache_free(), such as by KASAN, doesn't reference a freed
+ * policy.
+ */
+void mpol_put_task_policy(struct task_struct *task)
+{
+ struct mempolicy *pol;
+
+ task_lock(task);
+ pol = task->mempolicy;
+ task->mempolicy = NULL;
+ task_unlock(task);
+ mpol_put(pol);
+}
+
+static void sp_delete(struct shared_policy *sp, struct sp_node *n)
+{
+ pr_debug("deleting %lx-l%lx\n", n->start, n->end);
+ rb_erase(&n->nd, &sp->root);
+ sp_free(n);
+}
+
+static void sp_node_init(struct sp_node *node, unsigned long start,
+ unsigned long end, struct mempolicy *pol)
+{
+ node->start = start;
+ node->end = end;
+ node->policy = pol;
+}
+
+static struct sp_node *sp_alloc(unsigned long start, unsigned long end,
+ struct mempolicy *pol)
+{
+ struct sp_node *n;
+ struct mempolicy *newpol;
+
+ n = kmem_cache_alloc(sn_cache, GFP_KERNEL);
+ if (!n)
+ return NULL;
+
+ newpol = mpol_dup(pol);
+ if (IS_ERR(newpol)) {
+ kmem_cache_free(sn_cache, n);
+ return NULL;
+ }
+ newpol->flags |= MPOL_F_SHARED;
+ sp_node_init(n, start, end, newpol);
+
+ return n;
+}
+
+/* Replace a policy range. */
+static int shared_policy_replace(struct shared_policy *sp, unsigned long start,
+ unsigned long end, struct sp_node *new)
+{
+ struct sp_node *n;
+ struct sp_node *n_new = NULL;
+ struct mempolicy *mpol_new = NULL;
+ int ret = 0;
+
+restart:
+ write_lock(&sp->lock);
+ n = sp_lookup(sp, start, end);
+ /* Take care of old policies in the same range. */
+ while (n && n->start < end) {
+ struct rb_node *next = rb_next(&n->nd);
+ if (n->start >= start) {
+ if (n->end <= end)
+ sp_delete(sp, n);
+ else
+ n->start = end;
+ } else {
+ /* Old policy spanning whole new range. */
+ if (n->end > end) {
+ if (!n_new)
+ goto alloc_new;
+
+ *mpol_new = *n->policy;
+ atomic_set(&mpol_new->refcnt, 1);
+ sp_node_init(n_new, end, n->end, mpol_new);
+ n->end = start;
+ sp_insert(sp, n_new);
+ n_new = NULL;
+ mpol_new = NULL;
+ break;
+ } else
+ n->end = start;
+ }
+ if (!next)
+ break;
+ n = rb_entry(next, struct sp_node, nd);
+ }
+ if (new)
+ sp_insert(sp, new);
+ write_unlock(&sp->lock);
+ ret = 0;
+
+err_out:
+ if (mpol_new)
+ mpol_put(mpol_new);
+ if (n_new)
+ kmem_cache_free(sn_cache, n_new);
+
+ return ret;
+
+alloc_new:
+ write_unlock(&sp->lock);
+ ret = -ENOMEM;
+ n_new = kmem_cache_alloc(sn_cache, GFP_KERNEL);
+ if (!n_new)
+ goto err_out;
+ mpol_new = kmem_cache_alloc(policy_cache, GFP_KERNEL);
+ if (!mpol_new)
+ goto err_out;
+ goto restart;
+}
+
+/**
+ * mpol_shared_policy_init - initialize shared policy for inode
+ * @sp: pointer to inode shared policy
+ * @mpol: struct mempolicy to install
+ *
+ * Install non-NULL @mpol in inode's shared policy rb-tree.
+ * On entry, the current task has a reference on a non-NULL @mpol.
+ * This must be released on exit.
+ * This is called at get_inode() calls and we can use GFP_KERNEL.
+ */
+void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol)
+{
+ int ret;
+
+ sp->root = RB_ROOT; /* empty tree == default mempolicy */
+ rwlock_init(&sp->lock);
+
+ if (mpol) {
+ struct vm_area_struct pvma;
+ struct mempolicy *new;
+ NODEMASK_SCRATCH(scratch);
+
+ if (!scratch)
+ goto put_mpol;
+ /* contextualize the tmpfs mount point mempolicy */
+ new = mpol_new(mpol->mode, mpol->flags, &mpol->w.user_nodemask);
+ if (IS_ERR(new))
+ goto free_scratch; /* no valid nodemask intersection */
+
+ task_lock(current);
+ ret = mpol_set_nodemask(new, &mpol->w.user_nodemask, scratch);
+ task_unlock(current);
+ if (ret)
+ goto put_new;
+
+ /* Create pseudo-vma that contains just the policy */
+ vma_init(&pvma, NULL);
+ pvma.vm_end = TASK_SIZE; /* policy covers entire file */
+ mpol_set_shared_policy(sp, &pvma, new); /* adds ref */
+
+put_new:
+ mpol_put(new); /* drop initial ref */
+free_scratch:
+ NODEMASK_SCRATCH_FREE(scratch);
+put_mpol:
+ mpol_put(mpol); /* drop our incoming ref on sb mpol */
+ }
+}
+
+int mpol_set_shared_policy(struct shared_policy *info,
+ struct vm_area_struct *vma, struct mempolicy *npol)
+{
+ int err;
+ struct sp_node *new = NULL;
+ unsigned long sz = vma_pages(vma);
+
+ pr_debug("set_shared_policy %lx sz %lu %d %d %lx\n",
+ vma->vm_pgoff,
+ sz, npol ? npol->mode : -1,
+ npol ? npol->flags : -1,
+ npol ? nodes_addr(npol->v.nodes)[0] : NUMA_NO_NODE);
+
+ if (npol) {
+ new = sp_alloc(vma->vm_pgoff, vma->vm_pgoff + sz, npol);
+ if (!new)
+ return -ENOMEM;
+ }
+ err = shared_policy_replace(info, vma->vm_pgoff, vma->vm_pgoff+sz, new);
+ if (err && new)
+ sp_free(new);
+ return err;
+}
+
+/* Free a backing policy store on inode delete. */
+void mpol_free_shared_policy(struct shared_policy *p)
+{
+ struct sp_node *n;
+ struct rb_node *next;
+
+ if (!p->root.rb_node)
+ return;
+ write_lock(&p->lock);
+ next = rb_first(&p->root);
+ while (next) {
+ n = rb_entry(next, struct sp_node, nd);
+ next = rb_next(&n->nd);
+ sp_delete(p, n);
+ }
+ write_unlock(&p->lock);
+}
+
+#ifdef CONFIG_NUMA_BALANCING
+static int __initdata numabalancing_override;
+
+static void __init check_numabalancing_enable(void)
+{
+ bool numabalancing_default = false;
+
+ if (IS_ENABLED(CONFIG_NUMA_BALANCING_DEFAULT_ENABLED))
+ numabalancing_default = true;
+
+ /* Parsed by setup_numabalancing. override == 1 enables, -1 disables */
+ if (numabalancing_override)
+ set_numabalancing_state(numabalancing_override == 1);
+
+ if (num_online_nodes() > 1 && !numabalancing_override) {
+ pr_info("%s automatic NUMA balancing. Configure with numa_balancing= or the kernel.numa_balancing sysctl\n",
+ numabalancing_default ? "Enabling" : "Disabling");
+ set_numabalancing_state(numabalancing_default);
+ }
+}
+
+static int __init setup_numabalancing(char *str)
+{
+ int ret = 0;
+ if (!str)
+ goto out;
+
+ if (!strcmp(str, "enable")) {
+ numabalancing_override = 1;
+ ret = 1;
+ } else if (!strcmp(str, "disable")) {
+ numabalancing_override = -1;
+ ret = 1;
+ }
+out:
+ if (!ret)
+ pr_warn("Unable to parse numa_balancing=\n");
+
+ return ret;
+}
+__setup("numa_balancing=", setup_numabalancing);
+#else
+static inline void __init check_numabalancing_enable(void)
+{
+}
+#endif /* CONFIG_NUMA_BALANCING */
+
+/* assumes fs == KERNEL_DS */
+void __init numa_policy_init(void)
+{
+ nodemask_t interleave_nodes;
+ unsigned long largest = 0;
+ int nid, prefer = 0;
+
+ policy_cache = kmem_cache_create("numa_policy",
+ sizeof(struct mempolicy),
+ 0, SLAB_PANIC, NULL);
+
+ sn_cache = kmem_cache_create("shared_policy_node",
+ sizeof(struct sp_node),
+ 0, SLAB_PANIC, NULL);
+
+ for_each_node(nid) {
+ preferred_node_policy[nid] = (struct mempolicy) {
+ .refcnt = ATOMIC_INIT(1),
+ .mode = MPOL_PREFERRED,
+ .flags = MPOL_F_MOF | MPOL_F_MORON,
+ .v = { .preferred_node = nid, },
+ };
+ }
+
+ /*
+ * Set interleaving policy for system init. Interleaving is only
+ * enabled across suitably sized nodes (default is >= 16MB), or
+ * fall back to the largest node if they're all smaller.
+ */
+ nodes_clear(interleave_nodes);
+ for_each_node_state(nid, N_MEMORY) {
+ unsigned long total_pages = node_present_pages(nid);
+
+ /* Preserve the largest node */
+ if (largest < total_pages) {
+ largest = total_pages;
+ prefer = nid;
+ }
+
+ /* Interleave this node? */
+ if ((total_pages << PAGE_SHIFT) >= (16 << 20))
+ node_set(nid, interleave_nodes);
+ }
+
+ /* All too small, use the largest */
+ if (unlikely(nodes_empty(interleave_nodes)))
+ node_set(prefer, interleave_nodes);
+
+ if (do_set_mempolicy(MPOL_INTERLEAVE, 0, &interleave_nodes))
+ pr_err("%s: interleaving failed\n", __func__);
+
+ check_numabalancing_enable();
+}
+
+/* Reset policy of current process to default */
+void numa_default_policy(void)
+{
+ do_set_mempolicy(MPOL_DEFAULT, 0, NULL);
+}
+
+/*
+ * Parse and format mempolicy from/to strings
+ */
+
+/*
+ * "local" is implemented internally by MPOL_PREFERRED with MPOL_F_LOCAL flag.
+ */
+static const char * const policy_modes[] =
+{
+ [MPOL_DEFAULT] = "default",
+ [MPOL_PREFERRED] = "prefer",
+ [MPOL_BIND] = "bind",
+ [MPOL_INTERLEAVE] = "interleave",
+ [MPOL_LOCAL] = "local",
+};
+
+
+#ifdef CONFIG_TMPFS
+/**
+ * mpol_parse_str - parse string to mempolicy, for tmpfs mpol mount option.
+ * @str: string containing mempolicy to parse
+ * @mpol: pointer to struct mempolicy pointer, returned on success.
+ *
+ * Format of input:
+ * <mode>[=<flags>][:<nodelist>]
+ *
+ * On success, returns 0, else 1
+ */
+int mpol_parse_str(char *str, struct mempolicy **mpol)
+{
+ struct mempolicy *new = NULL;
+ unsigned short mode;
+ unsigned short mode_flags;
+ nodemask_t nodes;
+ char *nodelist = strchr(str, ':');
+ char *flags = strchr(str, '=');
+ int err = 1;
+
+ if (nodelist) {
+ /* NUL-terminate mode or flags string */
+ *nodelist++ = '\0';
+ if (nodelist_parse(nodelist, nodes))
+ goto out;
+ if (!nodes_subset(nodes, node_states[N_MEMORY]))
+ goto out;
+ } else
+ nodes_clear(nodes);
+
+ if (flags)
+ *flags++ = '\0'; /* terminate mode string */
+
+ for (mode = 0; mode < MPOL_MAX; mode++) {
+ if (!strcmp(str, policy_modes[mode])) {
+ break;
+ }
+ }
+ if (mode >= MPOL_MAX)
+ goto out;
+
+ switch (mode) {
+ case MPOL_PREFERRED:
+ /*
+ * Insist on a nodelist of one node only
+ */
+ if (nodelist) {
+ char *rest = nodelist;
+ while (isdigit(*rest))
+ rest++;
+ if (*rest)
+ goto out;
+ }
+ break;
+ case MPOL_INTERLEAVE:
+ /*
+ * Default to online nodes with memory if no nodelist
+ */
+ if (!nodelist)
+ nodes = node_states[N_MEMORY];
+ break;
+ case MPOL_LOCAL:
+ /*
+ * Don't allow a nodelist; mpol_new() checks flags
+ */
+ if (nodelist)
+ goto out;
+ mode = MPOL_PREFERRED;
+ break;
+ case MPOL_DEFAULT:
+ /*
+ * Insist on a empty nodelist
+ */
+ if (!nodelist)
+ err = 0;
+ goto out;
+ case MPOL_BIND:
+ /*
+ * Insist on a nodelist
+ */
+ if (!nodelist)
+ goto out;
+ }
+
+ mode_flags = 0;
+ if (flags) {
+ /*
+ * Currently, we only support two mutually exclusive
+ * mode flags.
+ */
+ if (!strcmp(flags, "static"))
+ mode_flags |= MPOL_F_STATIC_NODES;
+ else if (!strcmp(flags, "relative"))
+ mode_flags |= MPOL_F_RELATIVE_NODES;
+ else
+ goto out;
+ }
+
+ new = mpol_new(mode, mode_flags, &nodes);
+ if (IS_ERR(new))
+ goto out;
+
+ /*
+ * Save nodes for mpol_to_str() to show the tmpfs mount options
+ * for /proc/mounts, /proc/pid/mounts and /proc/pid/mountinfo.
+ */
+ if (mode != MPOL_PREFERRED)
+ new->v.nodes = nodes;
+ else if (nodelist)
+ new->v.preferred_node = first_node(nodes);
+ else
+ new->flags |= MPOL_F_LOCAL;
+
+ /*
+ * Save nodes for contextualization: this will be used to "clone"
+ * the mempolicy in a specific context [cpuset] at a later time.
+ */
+ new->w.user_nodemask = nodes;
+
+ err = 0;
+
+out:
+ /* Restore string for error message */
+ if (nodelist)
+ *--nodelist = ':';
+ if (flags)
+ *--flags = '=';
+ if (!err)
+ *mpol = new;
+ return err;
+}
+#endif /* CONFIG_TMPFS */
+
+/**
+ * mpol_to_str - format a mempolicy structure for printing
+ * @buffer: to contain formatted mempolicy string
+ * @maxlen: length of @buffer
+ * @pol: pointer to mempolicy to be formatted
+ *
+ * Convert @pol into a string. If @buffer is too short, truncate the string.
+ * Recommend a @maxlen of at least 32 for the longest mode, "interleave", the
+ * longest flag, "relative", and to display at least a few node ids.
+ */
+void mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol)
+{
+ char *p = buffer;
+ nodemask_t nodes = NODE_MASK_NONE;
+ unsigned short mode = MPOL_DEFAULT;
+ unsigned short flags = 0;
+
+ if (pol && pol != &default_policy && !(pol->flags & MPOL_F_MORON)) {
+ mode = pol->mode;
+ flags = pol->flags;
+ }
+
+ switch (mode) {
+ case MPOL_DEFAULT:
+ break;
+ case MPOL_PREFERRED:
+ if (flags & MPOL_F_LOCAL)
+ mode = MPOL_LOCAL;
+ else
+ node_set(pol->v.preferred_node, nodes);
+ break;
+ case MPOL_BIND:
+ case MPOL_INTERLEAVE:
+ nodes = pol->v.nodes;
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ snprintf(p, maxlen, "unknown");
+ return;
+ }
+
+ p += snprintf(p, maxlen, "%s", policy_modes[mode]);
+
+ if (flags & MPOL_MODE_FLAGS) {
+ p += snprintf(p, buffer + maxlen - p, "=");
+
+ /*
+ * Currently, the only defined flags are mutually exclusive
+ */
+ if (flags & MPOL_F_STATIC_NODES)
+ p += snprintf(p, buffer + maxlen - p, "static");
+ else if (flags & MPOL_F_RELATIVE_NODES)
+ p += snprintf(p, buffer + maxlen - p, "relative");
+ }
+
+ if (!nodes_empty(nodes))
+ p += scnprintf(p, buffer + maxlen - p, ":%*pbl",
+ nodemask_pr_args(&nodes));
+}