#include <linux/swap.h>
#include <linux/capability.h>
#include <linux/fs.h>
+#include <linux/swapops.h>
#include <linux/highmem.h>
#include <linux/security.h>
#include <linux/syscalls.h>
#include <linux/mmu_notifier.h>
#include <linux/sched/sysctl.h>
+#include <linux/uaccess.h>
+#include <linux/mm-arch-hooks.h>
-#include <asm/uaccess.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
return pmd;
}
+static pte_t move_soft_dirty_pte(pte_t pte)
+{
+ /*
+ * Set soft dirty bit so we can notice
+ * in userspace the ptes were moved.
+ */
+#ifdef CONFIG_MEM_SOFT_DIRTY
+ if (pte_present(pte))
+ pte = pte_mksoft_dirty(pte);
+ else if (is_swap_pte(pte))
+ pte = pte_swp_mksoft_dirty(pte);
+#endif
+ return pte;
+}
+
static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd,
unsigned long old_addr, unsigned long old_end,
struct vm_area_struct *new_vma, pmd_t *new_pmd,
spinlock_t *old_ptl, *new_ptl;
/*
- * When need_rmap_locks is true, we take the i_mmap_mutex and anon_vma
+ * When need_rmap_locks is true, we take the i_mmap_rwsem and anon_vma
* locks to ensure that rmap will always observe either the old or the
* new ptes. This is the easiest way to avoid races with
* truncate_pagecache(), page migration, etc...
if (need_rmap_locks) {
if (vma->vm_file) {
mapping = vma->vm_file->f_mapping;
- mutex_lock(&mapping->i_mmap_mutex);
+ i_mmap_lock_write(mapping);
}
if (vma->anon_vma) {
anon_vma = vma->anon_vma;
continue;
pte = ptep_get_and_clear(mm, old_addr, old_pte);
pte = move_pte(pte, new_vma->vm_page_prot, old_addr, new_addr);
+ pte = move_soft_dirty_pte(pte);
set_pte_at(mm, new_addr, new_pte, pte);
}
if (anon_vma)
anon_vma_unlock_write(anon_vma);
if (mapping)
- mutex_unlock(&mapping->i_mmap_mutex);
+ i_mmap_unlock_write(mapping);
}
#define LATENCY_LIMIT (64 * PAGE_SIZE)
break;
if (pmd_trans_huge(*old_pmd)) {
int err = 0;
- if (extent == HPAGE_PMD_SIZE)
+ if (extent == HPAGE_PMD_SIZE) {
+ VM_BUG_ON_VMA(vma->vm_file || !vma->anon_vma,
+ vma);
+ /* See comment in move_ptes() */
+ if (need_rmap_locks)
+ anon_vma_lock_write(vma->anon_vma);
err = move_huge_pmd(vma, new_vma, old_addr,
new_addr, old_end,
old_pmd, new_pmd);
+ if (need_rmap_locks)
+ anon_vma_unlock_write(vma->anon_vma);
+ }
if (err > 0) {
need_flush = true;
continue;
moved_len = move_page_tables(vma, old_addr, new_vma, new_addr, old_len,
need_rmap_locks);
if (moved_len < old_len) {
+ err = -ENOMEM;
+ } else if (vma->vm_ops && vma->vm_ops->mremap) {
+ err = vma->vm_ops->mremap(new_vma);
+ }
+
+ if (unlikely(err)) {
/*
* On error, move entries back from new area to old,
* which will succeed since page tables still there,
vma = new_vma;
old_len = new_len;
old_addr = new_addr;
- new_addr = -ENOMEM;
+ new_addr = err;
+ } else {
+ arch_remap(mm, old_addr, old_addr + old_len,
+ new_addr, new_addr + new_len);
}
/* Conceal VM_ACCOUNT so old reservation is not undone */
{
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma = find_vma(mm, addr);
+ unsigned long pgoff;
if (!vma || vma->vm_start > addr)
- goto Efault;
+ return ERR_PTR(-EFAULT);
if (is_vm_hugetlb_page(vma))
- goto Einval;
+ return ERR_PTR(-EINVAL);
/* We can't remap across vm area boundaries */
if (old_len > vma->vm_end - addr)
- goto Efault;
+ return ERR_PTR(-EFAULT);
+
+ if (new_len == old_len)
+ return vma;
/* 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;
- }
+ pgoff = (addr - vma->vm_start) >> PAGE_SHIFT;
+ pgoff += vma->vm_pgoff;
+ if (pgoff + (new_len >> PAGE_SHIFT) < pgoff)
+ return ERR_PTR(-EINVAL);
+
+ if (vma->vm_flags & (VM_DONTEXPAND | VM_PFNMAP))
+ return ERR_PTR(-EFAULT);
if (vma->vm_flags & VM_LOCKED) {
unsigned long locked, lock_limit;
lock_limit = rlimit(RLIMIT_MEMLOCK);
locked += new_len - old_len;
if (locked > lock_limit && !capable(CAP_IPC_LOCK))
- goto Eagain;
+ return ERR_PTR(-EAGAIN);
}
if (!may_expand_vm(mm, (new_len - old_len) >> PAGE_SHIFT))
- goto Enomem;
+ return ERR_PTR(-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;
+ return ERR_PTR(-ENOMEM);
*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 charged = 0;
unsigned long map_flags;
- if (new_addr & ~PAGE_MASK)
+ if (offset_in_page(new_addr))
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)
+ /* Ensure the old/new locations do not overlap */
+ if (addr + old_len > new_addr && new_addr + new_len > addr)
goto out;
ret = do_munmap(mm, new_addr, new_len);
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)
+ if (offset_in_page(ret))
goto out1;
ret = move_vma(vma, addr, old_len, new_len, new_addr, locked);
- if (!(ret & ~PAGE_MASK))
+ if (!(offset_in_page(ret)))
goto out;
out1:
vm_unacct_memory(charged);
unsigned long charged = 0;
bool locked = false;
- down_write(¤t->mm->mmap_sem);
-
if (flags & ~(MREMAP_FIXED | MREMAP_MAYMOVE))
- goto out;
+ return ret;
- if (addr & ~PAGE_MASK)
- goto out;
+ if (flags & MREMAP_FIXED && !(flags & MREMAP_MAYMOVE))
+ return ret;
+
+ if (offset_in_page(addr))
+ return ret;
old_len = PAGE_ALIGN(old_len);
new_len = PAGE_ALIGN(new_len);
* a zero new-len is nonsensical.
*/
if (!new_len)
- goto out;
+ return ret;
+
+ down_write(¤t->mm->mmap_sem);
if (flags & MREMAP_FIXED) {
- if (flags & MREMAP_MAYMOVE)
- ret = mremap_to(addr, old_len, new_addr, new_len,
- &locked);
+ ret = mremap_to(addr, old_len, new_addr, new_len,
+ &locked);
goto out;
}
vma->vm_pgoff +
((addr - vma->vm_start) >> PAGE_SHIFT),
map_flags);
- if (new_addr & ~PAGE_MASK) {
+ if (offset_in_page(new_addr)) {
ret = new_addr;
goto out;
}
ret = move_vma(vma, addr, old_len, new_len, new_addr, &locked);
}
out:
- if (ret & ~PAGE_MASK)
+ if (offset_in_page(ret)) {
vm_unacct_memory(charged);
+ locked = 0;
+ }
up_write(¤t->mm->mmap_sem);
if (locked && new_len > old_len)
mm_populate(new_addr + old_len, new_len - old_len);