#include <linux/shm.h>
#include <linux/mman.h>
#include <linux/swap.h>
+#include <linux/capability.h>
#include <linux/fs.h>
#include <linux/highmem.h>
#include <linux/security.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
-static pte_t *get_one_pte_map_nested(struct mm_struct *mm, unsigned long addr)
-{
- pgd_t *pgd;
- pud_t *pud;
- pmd_t *pmd;
- pte_t *pte = NULL;
-
- pgd = pgd_offset(mm, addr);
- if (pgd_none_or_clear_bad(pgd))
- goto end;
-
- pud = pud_offset(pgd, addr);
- if (pud_none_or_clear_bad(pud))
- goto end;
-
- pmd = pmd_offset(pud, addr);
- if (pmd_none_or_clear_bad(pmd))
- goto end;
-
- pte = pte_offset_map_nested(pmd, addr);
- if (pte_none(*pte)) {
- pte_unmap_nested(pte);
- pte = NULL;
- }
-end:
- return pte;
-}
-
-static pte_t *get_one_pte_map(struct mm_struct *mm, unsigned long addr)
+static pmd_t *get_old_pmd(struct mm_struct *mm, unsigned long addr)
{
pgd_t *pgd;
pud_t *pud;
if (pmd_none_or_clear_bad(pmd))
return NULL;
- return pte_offset_map(pmd, addr);
+ return pmd;
}
-static inline pte_t *alloc_one_pte_map(struct mm_struct *mm, unsigned long addr)
+static pmd_t *alloc_new_pmd(struct mm_struct *mm, unsigned long addr)
{
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
- pte_t *pte = NULL;
pgd = pgd_offset(mm, addr);
-
pud = pud_alloc(mm, pgd, addr);
if (!pud)
return NULL;
+
pmd = pmd_alloc(mm, pud, addr);
- if (pmd)
- pte = pte_alloc_map(mm, pmd, addr);
- return pte;
+ if (!pmd)
+ return NULL;
+
+ if (!pmd_present(*pmd) && __pte_alloc(mm, pmd, addr))
+ return NULL;
+
+ return pmd;
}
-static int
-move_one_page(struct vm_area_struct *vma, unsigned long old_addr,
- struct vm_area_struct *new_vma, unsigned long new_addr)
+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,
+ unsigned long new_addr)
{
struct address_space *mapping = NULL;
struct mm_struct *mm = vma->vm_mm;
- int error = 0;
- pte_t *src, *dst;
+ pte_t *old_pte, *new_pte, pte;
+ spinlock_t *old_ptl, *new_ptl;
if (vma->vm_file) {
/*
new_vma->vm_truncate_count != vma->vm_truncate_count)
new_vma->vm_truncate_count = 0;
}
- spin_lock(&mm->page_table_lock);
- src = get_one_pte_map_nested(mm, old_addr);
- if (src) {
- /*
- * Look to see whether alloc_one_pte_map needs to perform a
- * memory allocation. If it does then we need to drop the
- * atomic kmap
- */
- dst = get_one_pte_map(mm, new_addr);
- if (unlikely(!dst)) {
- pte_unmap_nested(src);
- if (mapping)
- spin_unlock(&mapping->i_mmap_lock);
- dst = alloc_one_pte_map(mm, new_addr);
- if (mapping && !spin_trylock(&mapping->i_mmap_lock)) {
- spin_unlock(&mm->page_table_lock);
- spin_lock(&mapping->i_mmap_lock);
- spin_lock(&mm->page_table_lock);
- }
- src = get_one_pte_map_nested(mm, old_addr);
- }
- /*
- * Since alloc_one_pte_map can drop and re-acquire
- * page_table_lock, we should re-check the src entry...
- */
- if (src) {
- if (dst) {
- pte_t pte;
- pte = ptep_clear_flush(vma, old_addr, src);
-
- /* ZERO_PAGE can be dependant on virtual addr */
- pte = move_pte(pte, new_vma->vm_page_prot,
- old_addr, new_addr);
- set_pte_at(mm, new_addr, dst, pte);
- } else
- error = -ENOMEM;
- pte_unmap_nested(src);
- }
- if (dst)
- pte_unmap(dst);
+ /*
+ * We don't have to worry about the ordering of src and dst
+ * 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_ptl = pte_lockptr(mm, new_pmd);
+ if (new_ptl != old_ptl)
+ spin_lock(new_ptl);
+
+ for (; old_addr < old_end; old_pte++, old_addr += PAGE_SIZE,
+ new_pte++, new_addr += PAGE_SIZE) {
+ if (pte_none(*old_pte))
+ continue;
+ pte = ptep_clear_flush(vma, old_addr, old_pte);
+ /* ZERO_PAGE can be dependant on virtual addr */
+ pte = move_pte(pte, new_vma->vm_page_prot, old_addr, new_addr);
+ set_pte_at(mm, new_addr, new_pte, pte);
}
- spin_unlock(&mm->page_table_lock);
+
+ if (new_ptl != old_ptl)
+ spin_unlock(new_ptl);
+ pte_unmap_nested(new_pte - 1);
+ pte_unmap_unlock(old_pte - 1, old_ptl);
if (mapping)
spin_unlock(&mapping->i_mmap_lock);
- return error;
}
+#define LATENCY_LIMIT (64 * PAGE_SIZE)
+
static unsigned long move_page_tables(struct vm_area_struct *vma,
unsigned long old_addr, struct vm_area_struct *new_vma,
unsigned long new_addr, unsigned long len)
{
- unsigned long offset;
+ unsigned long extent, next, old_end;
+ pmd_t *old_pmd, *new_pmd;
- flush_cache_range(vma, old_addr, old_addr + len);
+ old_end = old_addr + len;
+ flush_cache_range(vma, old_addr, old_end);
- /*
- * This is not the clever way to do this, but we're taking the
- * easy way out on the assumption that most remappings will be
- * only a few pages.. This also makes error recovery easier.
- */
- for (offset = 0; offset < len; offset += PAGE_SIZE) {
- if (move_one_page(vma, old_addr + offset,
- new_vma, new_addr + offset) < 0)
- break;
+ 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;
+ extent = next - 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);
+ if (!new_pmd)
+ break;
+ next = (new_addr + PMD_SIZE) & PMD_MASK;
+ if (extent > next - new_addr)
+ extent = next - new_addr;
+ if (extent > LATENCY_LIMIT)
+ extent = LATENCY_LIMIT;
+ move_ptes(vma, old_pmd, old_addr, old_addr + extent,
+ new_vma, new_pmd, new_addr);
}
- return offset;
+
+ return len + old_addr - old_end; /* how much done */
}
static unsigned long move_vma(struct vm_area_struct *vma,
unsigned long new_pgoff;
unsigned long moved_len;
unsigned long excess = 0;
+ unsigned long hiwater_vm;
int split = 0;
/*
}
/*
- * if we failed to move page tables we still do total_vm increment
- * since do_munmap() will decrement it by old_len == new_len
+ * If we failed to move page tables we still do total_vm increment
+ * since do_munmap() will decrement it by old_len == new_len.
+ *
+ * Since total_vm is about to be raised artificially high for a
+ * moment, we need to restore high watermark afterwards: if stats
+ * are taken meanwhile, total_vm and hiwater_vm appear too high.
+ * If this were a serious issue, we'd add a flag to do_munmap().
*/
+ hiwater_vm = mm->hiwater_vm;
mm->total_vm += new_len >> PAGE_SHIFT;
- __vm_stat_account(mm, vma->vm_flags, vma->vm_file, new_len>>PAGE_SHIFT);
+ vm_stat_account(mm, vma->vm_flags, vma->vm_file, new_len>>PAGE_SHIFT);
if (do_munmap(mm, old_addr, old_len) < 0) {
/* OOM: unable to split vma, just get accounts right */
vm_unacct_memory(excess >> PAGE_SHIFT);
excess = 0;
}
+ mm->hiwater_vm = hiwater_vm;
/* Restore VM_ACCOUNT if one or two pieces of vma left */
if (excess) {
unsigned long old_len, unsigned long new_len,
unsigned long flags, unsigned long new_addr)
{
+ struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
unsigned long ret = -EINVAL;
unsigned long charged = 0;
if ((addr <= new_addr) && (addr+old_len) > new_addr)
goto out;
- ret = do_munmap(current->mm, new_addr, new_len);
+ ret = do_munmap(mm, new_addr, new_len);
if (ret)
goto out;
}
* do_munmap does all the needed commit accounting
*/
if (old_len >= new_len) {
- ret = do_munmap(current->mm, addr+new_len, old_len - new_len);
+ ret = do_munmap(mm, addr+new_len, old_len - new_len);
if (ret && old_len != new_len)
goto out;
ret = addr;
* Ok, we need to grow.. or relocate.
*/
ret = -EFAULT;
- vma = find_vma(current->mm, addr);
+ vma = find_vma(mm, addr);
if (!vma || vma->vm_start > addr)
goto out;
if (is_vm_hugetlb_page(vma)) {
/* We can't remap across vm area boundaries */
if (old_len > vma->vm_end - addr)
goto out;
- if (vma->vm_flags & VM_DONTEXPAND) {
+ 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 = current->mm->locked_vm << PAGE_SHIFT;
+ 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(current->mm, (new_len - old_len) >> PAGE_SHIFT)) {
+ if (!may_expand_vm(mm, (new_len - old_len) >> PAGE_SHIFT)) {
ret = -ENOMEM;
goto out;
}
vma_adjust(vma, vma->vm_start,
addr + new_len, vma->vm_pgoff, NULL);
- current->mm->total_vm += pages;
- __vm_stat_account(vma->vm_mm, vma->vm_flags,
- vma->vm_file, pages);
+ mm->total_vm += pages;
+ vm_stat_account(mm, vma->vm_flags, vma->vm_file, pages);
if (vma->vm_flags & VM_LOCKED) {
- current->mm->locked_vm += pages;
+ mm->locked_vm += pages;
make_pages_present(addr + old_len,
addr + new_len);
}
git.samba.org / sfrench / cifs-2.6.git / blobdiff