#include <linux/mm.h>
#include <linux/hugetlb.h>
-#include <linux/slab.h>
#include <linux/shm.h>
+#include <linux/ksm.h>
#include <linux/mman.h>
#include <linux/swap.h>
#include <linux/capability.h>
return NULL;
pmd = pmd_offset(pud, addr);
- if (pmd_none_or_clear_bad(pmd))
+ if (pmd_none(*pmd))
return NULL;
return pmd;
}
-static pmd_t *alloc_new_pmd(struct mm_struct *mm, unsigned long addr)
+static pmd_t *alloc_new_pmd(struct mm_struct *mm, struct vm_area_struct *vma,
+ unsigned long addr)
{
pgd_t *pgd;
pud_t *pud;
if (!pmd)
return NULL;
- if (!pmd_present(*pmd) && __pte_alloc(mm, pmd, addr))
- return NULL;
+ VM_BUG_ON(pmd_trans_huge(*pmd));
return pmd;
}
struct mm_struct *mm = vma->vm_mm;
pte_t *old_pte, *new_pte, pte;
spinlock_t *old_ptl, *new_ptl;
- unsigned long old_start;
- old_start = old_addr;
- mmu_notifier_invalidate_range_start(vma->vm_mm,
- old_start, old_end);
if (vma->vm_file) {
/*
* Subtle point from Rajesh Venkatasubramanian: before
- * moving file-based ptes, we must lock vmtruncate out,
- * since it might clean the dst vma before the src vma,
+ * moving file-based ptes, we must lock truncate_pagecache
+ * out, since it might clean the dst vma before the src vma,
* and we propagate stale pages into the dst afterward.
*/
mapping = vma->vm_file->f_mapping;
- spin_lock(&mapping->i_mmap_lock);
- if (new_vma->vm_truncate_count &&
- new_vma->vm_truncate_count != vma->vm_truncate_count)
- new_vma->vm_truncate_count = 0;
+ mutex_lock(&mapping->i_mmap_mutex);
}
/*
* pte locks because exclusive mmap_sem prevents deadlock.
*/
old_pte = pte_offset_map_lock(mm, old_pmd, old_addr, &old_ptl);
- new_pte = pte_offset_map_nested(new_pmd, new_addr);
+ new_pte = pte_offset_map(new_pmd, new_addr);
new_ptl = pte_lockptr(mm, new_pmd);
if (new_ptl != old_ptl)
spin_lock_nested(new_ptl, SINGLE_DEPTH_NESTING);
new_pte++, new_addr += PAGE_SIZE) {
if (pte_none(*old_pte))
continue;
- pte = ptep_clear_flush(vma, old_addr, old_pte);
+ pte = ptep_get_and_clear(mm, old_addr, old_pte);
pte = move_pte(pte, new_vma->vm_page_prot, old_addr, new_addr);
set_pte_at(mm, new_addr, new_pte, pte);
}
arch_leave_lazy_mmu_mode();
if (new_ptl != old_ptl)
spin_unlock(new_ptl);
- pte_unmap_nested(new_pte - 1);
+ pte_unmap(new_pte - 1);
pte_unmap_unlock(old_pte - 1, old_ptl);
if (mapping)
- spin_unlock(&mapping->i_mmap_lock);
- mmu_notifier_invalidate_range_end(vma->vm_mm, old_start, old_end);
+ mutex_unlock(&mapping->i_mmap_mutex);
}
#define LATENCY_LIMIT (64 * PAGE_SIZE)
{
unsigned long extent, next, old_end;
pmd_t *old_pmd, *new_pmd;
+ bool need_flush = false;
old_end = old_addr + len;
flush_cache_range(vma, old_addr, old_end);
+ mmu_notifier_invalidate_range_start(vma->vm_mm, old_addr, old_end);
+
for (; old_addr < old_end; old_addr += extent, new_addr += extent) {
cond_resched();
next = (old_addr + PMD_SIZE) & PMD_MASK;
- if (next - 1 > old_end)
- next = old_end;
+ /* even if next overflowed, extent below will be ok */
extent = next - old_addr;
+ if (extent > old_end - old_addr)
+ extent = old_end - old_addr;
old_pmd = get_old_pmd(vma->vm_mm, old_addr);
if (!old_pmd)
continue;
- new_pmd = alloc_new_pmd(vma->vm_mm, new_addr);
+ new_pmd = alloc_new_pmd(vma->vm_mm, vma, new_addr);
if (!new_pmd)
break;
+ if (pmd_trans_huge(*old_pmd)) {
+ int err = 0;
+ if (extent == HPAGE_PMD_SIZE)
+ err = move_huge_pmd(vma, new_vma, old_addr,
+ new_addr, old_end,
+ old_pmd, new_pmd);
+ if (err > 0) {
+ need_flush = true;
+ continue;
+ } else if (!err) {
+ split_huge_page_pmd(vma->vm_mm, old_pmd);
+ }
+ VM_BUG_ON(pmd_trans_huge(*old_pmd));
+ }
+ if (pmd_none(*new_pmd) && __pte_alloc(new_vma->vm_mm, new_vma,
+ new_pmd, new_addr))
+ break;
next = (new_addr + PMD_SIZE) & PMD_MASK;
if (extent > next - new_addr)
extent = next - new_addr;
extent = LATENCY_LIMIT;
move_ptes(vma, old_pmd, old_addr, old_addr + extent,
new_vma, new_pmd, new_addr);
+ need_flush = true;
}
+ if (likely(need_flush))
+ flush_tlb_range(vma, old_end-len, old_addr);
+
+ mmu_notifier_invalidate_range_end(vma->vm_mm, old_end-len, old_end);
return len + old_addr - old_end; /* how much done */
}
unsigned long excess = 0;
unsigned long hiwater_vm;
int split = 0;
+ int err;
/*
* We'd prefer to avoid failure later on in do_munmap:
if (mm->map_count >= sysctl_max_map_count - 3)
return -ENOMEM;
+ /*
+ * Advise KSM to break any KSM pages in the area to be moved:
+ * it would be confusing if they were to turn up at the new
+ * location, where they happen to coincide with different KSM
+ * pages recently unmapped. But leave vma->vm_flags as it was,
+ * so KSM can come around to merge on vma and new_vma afterwards.
+ */
+ err = ksm_madvise(vma, old_addr, old_addr + old_len,
+ MADV_UNMERGEABLE, &vm_flags);
+ if (err)
+ return err;
+
new_pgoff = vma->vm_pgoff + ((old_addr - vma->vm_start) >> PAGE_SHIFT);
new_vma = copy_vma(&vma, new_addr, new_len, new_pgoff);
if (!new_vma)
moved_len = move_page_tables(vma, old_addr, new_vma, new_addr, old_len);
if (moved_len < old_len) {
/*
+ * Before moving the page tables from the new vma to
+ * the old vma, we need to be sure the old vma is
+ * queued after new vma in the same_anon_vma list to
+ * prevent SMP races with rmap_walk (that could lead
+ * rmap_walk to miss some page table).
+ */
+ anon_vma_moveto_tail(vma);
+
+ /*
* On error, move entries back from new area to old,
* which will succeed since page tables still there,
* and then proceed to unmap new area instead of old.
return new_addr;
}
+static struct vm_area_struct *vma_to_resize(unsigned long addr,
+ unsigned long old_len, unsigned long new_len, unsigned long *p)
+{
+ struct mm_struct *mm = current->mm;
+ struct vm_area_struct *vma = find_vma(mm, addr);
+
+ if (!vma || vma->vm_start > addr)
+ goto Efault;
+
+ if (is_vm_hugetlb_page(vma))
+ goto Einval;
+
+ /* We can't remap across vm area boundaries */
+ if (old_len > vma->vm_end - addr)
+ goto Efault;
+
+ /* Need to be careful about a growing mapping */
+ if (new_len > old_len) {
+ unsigned long pgoff;
+
+ if (vma->vm_flags & (VM_DONTEXPAND | VM_PFNMAP))
+ goto Efault;
+ pgoff = (addr - vma->vm_start) >> PAGE_SHIFT;
+ pgoff += vma->vm_pgoff;
+ if (pgoff + (new_len >> PAGE_SHIFT) < pgoff)
+ goto Einval;
+ }
+
+ if (vma->vm_flags & VM_LOCKED) {
+ unsigned long locked, lock_limit;
+ locked = mm->locked_vm << PAGE_SHIFT;
+ lock_limit = rlimit(RLIMIT_MEMLOCK);
+ locked += new_len - old_len;
+ if (locked > lock_limit && !capable(CAP_IPC_LOCK))
+ goto Eagain;
+ }
+
+ if (!may_expand_vm(mm, (new_len - old_len) >> PAGE_SHIFT))
+ goto Enomem;
+
+ if (vma->vm_flags & VM_ACCOUNT) {
+ unsigned long charged = (new_len - old_len) >> PAGE_SHIFT;
+ if (security_vm_enough_memory_mm(mm, charged))
+ goto Efault;
+ *p = charged;
+ }
+
+ return vma;
+
+Efault: /* very odd choice for most of the cases, but... */
+ return ERR_PTR(-EFAULT);
+Einval:
+ return ERR_PTR(-EINVAL);
+Enomem:
+ return ERR_PTR(-ENOMEM);
+Eagain:
+ return ERR_PTR(-EAGAIN);
+}
+
+static unsigned long mremap_to(unsigned long addr,
+ unsigned long old_len, unsigned long new_addr,
+ unsigned long new_len)
+{
+ struct mm_struct *mm = current->mm;
+ struct vm_area_struct *vma;
+ unsigned long ret = -EINVAL;
+ unsigned long charged = 0;
+ unsigned long map_flags;
+
+ if (new_addr & ~PAGE_MASK)
+ goto out;
+
+ if (new_len > TASK_SIZE || new_addr > TASK_SIZE - new_len)
+ goto out;
+
+ /* Check if the location we're moving into overlaps the
+ * old location at all, and fail if it does.
+ */
+ if ((new_addr <= addr) && (new_addr+new_len) > addr)
+ goto out;
+
+ if ((addr <= new_addr) && (addr+old_len) > new_addr)
+ goto out;
+
+ ret = security_file_mmap(NULL, 0, 0, 0, new_addr, 1);
+ if (ret)
+ goto out;
+
+ ret = do_munmap(mm, new_addr, new_len);
+ if (ret)
+ goto out;
+
+ if (old_len >= new_len) {
+ ret = do_munmap(mm, addr+new_len, old_len - new_len);
+ if (ret && old_len != new_len)
+ goto out;
+ old_len = new_len;
+ }
+
+ vma = vma_to_resize(addr, old_len, new_len, &charged);
+ if (IS_ERR(vma)) {
+ ret = PTR_ERR(vma);
+ goto out;
+ }
+
+ map_flags = MAP_FIXED;
+ if (vma->vm_flags & VM_MAYSHARE)
+ map_flags |= MAP_SHARED;
+
+ ret = get_unmapped_area(vma->vm_file, new_addr, new_len, vma->vm_pgoff +
+ ((addr - vma->vm_start) >> PAGE_SHIFT),
+ map_flags);
+ if (ret & ~PAGE_MASK)
+ goto out1;
+
+ ret = move_vma(vma, addr, old_len, new_len, new_addr);
+ if (!(ret & ~PAGE_MASK))
+ goto out;
+out1:
+ vm_unacct_memory(charged);
+
+out:
+ return ret;
+}
+
+static int vma_expandable(struct vm_area_struct *vma, unsigned long delta)
+{
+ unsigned long end = vma->vm_end + delta;
+ if (end < vma->vm_end) /* overflow */
+ return 0;
+ if (vma->vm_next && vma->vm_next->vm_start < end) /* intersection */
+ return 0;
+ if (get_unmapped_area(NULL, vma->vm_start, end - vma->vm_start,
+ 0, MAP_FIXED) & ~PAGE_MASK)
+ return 0;
+ return 1;
+}
+
/*
* Expand (or shrink) an existing mapping, potentially moving it at the
* same time (controlled by the MREMAP_MAYMOVE flag and available VM space)
if (!new_len)
goto out;
- /* new_addr is only valid if MREMAP_FIXED is specified */
if (flags & MREMAP_FIXED) {
- if (new_addr & ~PAGE_MASK)
- goto out;
- if (!(flags & MREMAP_MAYMOVE))
- goto out;
-
- if (new_len > TASK_SIZE || new_addr > TASK_SIZE - new_len)
- goto out;
-
- /* Check if the location we're moving into overlaps the
- * old location at all, and fail if it does.
- */
- if ((new_addr <= addr) && (new_addr+new_len) > addr)
- goto out;
-
- if ((addr <= new_addr) && (addr+old_len) > new_addr)
- goto out;
-
- ret = security_file_mmap(NULL, 0, 0, 0, new_addr, 1);
- if (ret)
- goto out;
-
- ret = do_munmap(mm, new_addr, new_len);
- if (ret)
- goto out;
+ if (flags & MREMAP_MAYMOVE)
+ ret = mremap_to(addr, old_len, new_addr, new_len);
+ goto out;
}
/*
if (ret && old_len != new_len)
goto out;
ret = addr;
- if (!(flags & MREMAP_FIXED) || (new_addr == addr))
- goto out;
- old_len = new_len;
+ goto out;
}
/*
- * Ok, we need to grow.. or relocate.
+ * Ok, we need to grow..
*/
- ret = -EFAULT;
- vma = find_vma(mm, addr);
- if (!vma || vma->vm_start > addr)
- goto out;
- if (is_vm_hugetlb_page(vma)) {
- ret = -EINVAL;
- goto out;
- }
- /* We can't remap across vm area boundaries */
- if (old_len > vma->vm_end - addr)
- goto out;
- if (vma->vm_flags & (VM_DONTEXPAND | VM_PFNMAP)) {
- if (new_len > old_len)
- goto out;
- }
- if (vma->vm_flags & VM_LOCKED) {
- unsigned long locked, lock_limit;
- locked = mm->locked_vm << PAGE_SHIFT;
- lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur;
- locked += new_len - old_len;
- ret = -EAGAIN;
- if (locked > lock_limit && !capable(CAP_IPC_LOCK))
- goto out;
- }
- if (!may_expand_vm(mm, (new_len - old_len) >> PAGE_SHIFT)) {
- ret = -ENOMEM;
+ vma = vma_to_resize(addr, old_len, new_len, &charged);
+ if (IS_ERR(vma)) {
+ ret = PTR_ERR(vma);
goto out;
}
- if (vma->vm_flags & VM_ACCOUNT) {
- charged = (new_len - old_len) >> PAGE_SHIFT;
- if (security_vm_enough_memory(charged))
- goto out_nc;
- }
-
/* old_len exactly to the end of the area..
- * And we're not relocating the area.
*/
- if (old_len == vma->vm_end - addr &&
- !((flags & MREMAP_FIXED) && (addr != new_addr)) &&
- (old_len != new_len || !(flags & MREMAP_MAYMOVE))) {
- unsigned long max_addr = TASK_SIZE;
- if (vma->vm_next)
- max_addr = vma->vm_next->vm_start;
+ if (old_len == vma->vm_end - addr) {
/* can we just expand the current mapping? */
- if (max_addr - addr >= new_len) {
+ if (vma_expandable(vma, new_len - old_len)) {
int pages = (new_len - old_len) >> PAGE_SHIFT;
- vma_adjust(vma, vma->vm_start,
- addr + new_len, vma->vm_pgoff, NULL);
+ if (vma_adjust(vma, vma->vm_start, addr + new_len,
+ vma->vm_pgoff, NULL)) {
+ ret = -ENOMEM;
+ goto out;
+ }
mm->total_vm += pages;
vm_stat_account(mm, vma->vm_flags, vma->vm_file, pages);
*/
ret = -ENOMEM;
if (flags & MREMAP_MAYMOVE) {
- if (!(flags & MREMAP_FIXED)) {
- unsigned long map_flags = 0;
- if (vma->vm_flags & VM_MAYSHARE)
- map_flags |= MAP_SHARED;
-
- new_addr = get_unmapped_area(vma->vm_file, 0, new_len,
- vma->vm_pgoff, map_flags);
- if (new_addr & ~PAGE_MASK) {
- ret = new_addr;
- goto out;
- }
-
- ret = security_file_mmap(NULL, 0, 0, 0, new_addr, 1);
- if (ret)
- goto out;
+ unsigned long map_flags = 0;
+ if (vma->vm_flags & VM_MAYSHARE)
+ map_flags |= MAP_SHARED;
+
+ new_addr = get_unmapped_area(vma->vm_file, 0, new_len,
+ vma->vm_pgoff +
+ ((addr - vma->vm_start) >> PAGE_SHIFT),
+ map_flags);
+ if (new_addr & ~PAGE_MASK) {
+ ret = new_addr;
+ goto out;
}
+
+ ret = security_file_mmap(NULL, 0, 0, 0, new_addr, 1);
+ if (ret)
+ goto out;
ret = move_vma(vma, addr, old_len, new_len, new_addr);
}
out:
if (ret & ~PAGE_MASK)
vm_unacct_memory(charged);
-out_nc:
return ret;
}
projects / linux-flexiantxendom0-3.2.10.git / blobdiff