#include <linux/mempolicy.h>
#include <linux/personality.h>
#include <linux/syscalls.h>
-
+#include <linux/swap.h>
+#include <linux/swapops.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/cacheflush.h>
static void change_pte_range(struct mm_struct *mm, pmd_t *pmd,
unsigned long addr, unsigned long end, pgprot_t newprot)
{
- pte_t *pte;
+ pte_t *pte, oldpte;
+ spinlock_t *ptl;
- pte = pte_offset_map(pmd, addr);
+ pte = pte_offset_map_lock(mm, pmd, addr, &ptl);
do {
- if (pte_present(*pte)) {
+ oldpte = *pte;
+ if (pte_present(oldpte)) {
pte_t ptent;
/* Avoid an SMP race with hardware updated dirty/clean
ptent = pte_modify(ptep_get_and_clear(mm, addr, pte), newprot);
set_pte_at(mm, addr, pte, ptent);
lazy_mmu_prot_update(ptent);
+#ifdef CONFIG_MIGRATION
+ } else if (!pte_file(oldpte)) {
+ swp_entry_t entry = pte_to_swp_entry(oldpte);
+
+ if (is_write_migration_entry(entry)) {
+ /*
+ * A protection check is difficult so
+ * just be safe and disable write
+ */
+ make_migration_entry_read(&entry);
+ set_pte_at(mm, addr, pte,
+ swp_entry_to_pte(entry));
+ }
+#endif
}
+
} while (pte++, addr += PAGE_SIZE, addr != end);
- pte_unmap(pte - 1);
+ pte_unmap_unlock(pte - 1, ptl);
}
static inline void change_pmd_range(struct mm_struct *mm, pud_t *pud,
BUG_ON(addr >= end);
pgd = pgd_offset(mm, addr);
flush_cache_range(vma, addr, end);
- spin_lock(&mm->page_table_lock);
do {
next = pgd_addr_end(addr, end);
if (pgd_none_or_clear_bad(pgd))
change_pud_range(mm, pgd, addr, next, newprot);
} while (pgd++, addr = next, addr != end);
flush_tlb_range(vma, start, end);
- spin_unlock(&mm->page_table_lock);
}
static int
unsigned long oldflags = vma->vm_flags;
long nrpages = (end - start) >> PAGE_SHIFT;
unsigned long charged = 0;
+ unsigned int mask;
pgprot_t newprot;
pgoff_t pgoff;
int error;
* a MAP_NORESERVE private mapping to writable will now reserve.
*/
if (newflags & VM_WRITE) {
- if (!(oldflags & (VM_ACCOUNT|VM_WRITE|VM_SHARED|VM_HUGETLB))) {
+ if (!(oldflags & (VM_ACCOUNT|VM_WRITE|VM_SHARED))) {
charged = nrpages;
if (security_vm_enough_memory(charged))
return -ENOMEM;
}
}
- newprot = protection_map[newflags & 0xf];
-
/*
* First try to merge with previous and/or next vma.
*/
}
success:
+ /* Don't make the VMA automatically writable if it's shared, but the
+ * backer wishes to know when pages are first written to */
+ mask = VM_READ|VM_WRITE|VM_EXEC|VM_SHARED;
+ if (vma->vm_ops && vma->vm_ops->page_mkwrite)
+ mask &= ~VM_SHARED;
+
+ newprot = protection_map[newflags & mask];
+
/*
* vm_flags and vm_page_prot are protected by the mmap_sem
* held in write mode.
*/
vma->vm_flags = newflags;
vma->vm_page_prot = newprot;
- change_protection(vma, start, end, newprot);
- __vm_stat_account(mm, oldflags, vma->vm_file, -nrpages);
- __vm_stat_account(mm, newflags, vma->vm_file, nrpages);
+ if (is_vm_hugetlb_page(vma))
+ hugetlb_change_protection(vma, start, end, newprot);
+ else
+ change_protection(vma, start, end, newprot);
+ vm_stat_account(mm, oldflags, vma->vm_file, -nrpages);
+ vm_stat_account(mm, newflags, vma->vm_file, nrpages);
return 0;
fail:
/*
* Does the application expect PROT_READ to imply PROT_EXEC:
*/
- if (unlikely((prot & PROT_READ) &&
- (current->personality & READ_IMPLIES_EXEC)))
+ if ((prot & PROT_READ) && (current->personality & READ_IMPLIES_EXEC))
prot |= PROT_EXEC;
vm_flags = calc_vm_prot_bits(prot);
/* Here we know that vma->vm_start <= nstart < vma->vm_end. */
- if (is_vm_hugetlb_page(vma)) {
- error = -EACCES;
- goto out;
- }
-
newflags = vm_flags | (vma->vm_flags & ~(VM_READ | VM_WRITE | VM_EXEC));
/* newflags >> 4 shift VM_MAY% in place of VM_% */