* (C) Copyright 1994 Linus Torvalds
* (C) Copyright 2002 Christoph Hellwig
*
- * Address space accounting code <alan@redhat.com>
+ * Address space accounting code <alan@lxorguk.ukuu.org.uk>
* (C) Copyright 2002 Red Hat Inc, All Rights Reserved
*/
#include <linux/mm.h>
#include <linux/hugetlb.h>
-#include <linux/slab.h>
#include <linux/shm.h>
#include <linux/mman.h>
#include <linux/fs.h>
#include <linux/highmem.h>
#include <linux/security.h>
#include <linux/mempolicy.h>
-
+#include <linux/personality.h>
+#include <linux/syscalls.h>
+#include <linux/swap.h>
+#include <linux/swapops.h>
+#include <linux/mmu_notifier.h>
+#include <linux/migrate.h>
+#include <linux/perf_event.h>
#include <asm/uaccess.h>
-#include <asm/pgalloc.h>
#include <asm/pgtable.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
-static inline void
-change_pte_range(pmd_t *pmd, unsigned long address,
- unsigned long size, pgprot_t newprot)
+#ifndef pgprot_modify
+static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot)
{
- pte_t * pte;
- unsigned long end;
-
- if (pmd_none(*pmd))
- return;
- if (pmd_bad(*pmd)) {
- pmd_ERROR(*pmd);
- pmd_clear(pmd);
- return;
- }
- pte = pte_offset_map(pmd, address);
- address &= ~PMD_MASK;
- end = address + size;
- if (end > PMD_SIZE)
- end = PMD_SIZE;
+ return newprot;
+}
+#endif
+
+static void change_pte_range(struct mm_struct *mm, pmd_t *pmd,
+ unsigned long addr, unsigned long end, pgprot_t newprot,
+ int dirty_accountable)
+{
+ pte_t *pte, oldpte;
+ spinlock_t *ptl;
+
+ pte = pte_offset_map_lock(mm, pmd, addr, &ptl);
+ arch_enter_lazy_mmu_mode();
do {
- if (pte_present(*pte)) {
- pte_t entry;
+ oldpte = *pte;
+ if (pte_present(oldpte)) {
+ pte_t ptent;
+
+ ptent = ptep_modify_prot_start(mm, addr, pte);
+ ptent = pte_modify(ptent, newprot);
- /* Avoid an SMP race with hardware updated dirty/clean
- * bits by wiping the pte and then setting the new pte
- * into place.
+ /*
+ * Avoid taking write faults for pages we know to be
+ * dirty.
*/
- entry = ptep_get_and_clear(pte);
- set_pte(pte, pte_modify(entry, newprot));
+ if (dirty_accountable && pte_dirty(ptent))
+ ptent = pte_mkwrite(ptent);
+
+ ptep_modify_prot_commit(mm, addr, pte, ptent);
+ } else if (IS_ENABLED(CONFIG_MIGRATION) && !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));
+ }
}
- address += PAGE_SIZE;
- pte++;
- } while (address && (address < end));
- pte_unmap(pte - 1);
+ } while (pte++, addr += PAGE_SIZE, addr != end);
+ arch_leave_lazy_mmu_mode();
+ pte_unmap_unlock(pte - 1, ptl);
}
-static inline void
-change_pmd_range(pgd_t *pgd, unsigned long address,
- unsigned long size, pgprot_t newprot)
+static inline void change_pmd_range(struct vm_area_struct *vma, pud_t *pud,
+ unsigned long addr, unsigned long end, pgprot_t newprot,
+ int dirty_accountable)
{
- pmd_t * pmd;
- unsigned long end;
-
- if (pgd_none(*pgd))
- return;
- if (pgd_bad(*pgd)) {
- pgd_ERROR(*pgd);
- pgd_clear(pgd);
- return;
- }
- pmd = pmd_offset(pgd, address);
- address &= ~PGDIR_MASK;
- end = address + size;
- if (end > PGDIR_SIZE)
- end = PGDIR_SIZE;
+ pmd_t *pmd;
+ unsigned long next;
+
+ pmd = pmd_offset(pud, addr);
do {
- change_pte_range(pmd, address, end - address, newprot);
- address = (address + PMD_SIZE) & PMD_MASK;
- pmd++;
- } while (address && (address < end));
+ next = pmd_addr_end(addr, end);
+ if (pmd_trans_huge(*pmd)) {
+ if (next - addr != HPAGE_PMD_SIZE)
+ split_huge_page_pmd(vma->vm_mm, pmd);
+ else if (change_huge_pmd(vma, pmd, addr, newprot))
+ continue;
+ /* fall through */
+ }
+ if (pmd_none_or_clear_bad(pmd))
+ continue;
+ change_pte_range(vma->vm_mm, pmd, addr, next, newprot,
+ dirty_accountable);
+ } while (pmd++, addr = next, addr != end);
+}
+
+static inline void change_pud_range(struct vm_area_struct *vma, pgd_t *pgd,
+ unsigned long addr, unsigned long end, pgprot_t newprot,
+ int dirty_accountable)
+{
+ pud_t *pud;
+ unsigned long next;
+
+ pud = pud_offset(pgd, addr);
+ do {
+ next = pud_addr_end(addr, end);
+ if (pud_none_or_clear_bad(pud))
+ continue;
+ change_pmd_range(vma, pud, addr, next, newprot,
+ dirty_accountable);
+ } while (pud++, addr = next, addr != end);
}
-static void
-change_protection(struct vm_area_struct *vma, unsigned long start,
- unsigned long end, pgprot_t newprot)
+static void change_protection(struct vm_area_struct *vma,
+ unsigned long addr, unsigned long end, pgprot_t newprot,
+ int dirty_accountable)
{
- pgd_t *dir;
- unsigned long beg = start;
-
- dir = pgd_offset(current->mm, start);
- flush_cache_range(vma, beg, end);
- if (start >= end)
- BUG();
- spin_lock(¤t->mm->page_table_lock);
+ struct mm_struct *mm = vma->vm_mm;
+ pgd_t *pgd;
+ unsigned long next;
+ unsigned long start = addr;
+
+ BUG_ON(addr >= end);
+ pgd = pgd_offset(mm, addr);
+ flush_cache_range(vma, addr, end);
do {
- change_pmd_range(dir, start, end - start, newprot);
- start = (start + PGDIR_SIZE) & PGDIR_MASK;
- dir++;
- } while (start && (start < end));
- flush_tlb_range(vma, beg, end);
- spin_unlock(¤t->mm->page_table_lock);
- return;
+ next = pgd_addr_end(addr, end);
+ if (pgd_none_or_clear_bad(pgd))
+ continue;
+ change_pud_range(vma, pgd, addr, next, newprot,
+ dirty_accountable);
+ } while (pgd++, addr = next, addr != end);
+ flush_tlb_range(vma, start, end);
}
-static int
+int
mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev,
- unsigned long start, unsigned long end, unsigned int newflags)
+ unsigned long start, unsigned long end, unsigned long newflags)
{
- struct mm_struct * mm = vma->vm_mm;
+ struct mm_struct *mm = vma->vm_mm;
+ unsigned long oldflags = vma->vm_flags;
+ long nrpages = (end - start) >> PAGE_SHIFT;
unsigned long charged = 0;
- pgprot_t newprot;
pgoff_t pgoff;
int error;
+ int dirty_accountable = 0;
- if (newflags == vma->vm_flags) {
+ if (newflags == oldflags) {
*pprev = vma;
return 0;
}
/*
* If we make a private mapping writable we increase our commit;
* but (without finer accounting) cannot reduce our commit if we
- * make it unwritable again.
- *
- * FIXME? We haven't defined a VM_NORESERVE flag, so mprotecting
- * a MAP_NORESERVE private mapping to writable will now reserve.
+ * make it unwritable again. hugetlb mapping were accounted for
+ * even if read-only so there is no need to account for them here
*/
if (newflags & VM_WRITE) {
- if (!(vma->vm_flags & (VM_ACCOUNT|VM_WRITE|VM_SHARED|VM_HUGETLB))) {
- charged = (end - start) >> PAGE_SHIFT;
- if (security_vm_enough_memory(charged))
+ if (!(oldflags & (VM_ACCOUNT|VM_WRITE|VM_HUGETLB|
+ VM_SHARED|VM_NORESERVE))) {
+ charged = nrpages;
+ if (security_vm_enough_memory_mm(mm, charged))
return -ENOMEM;
newflags |= VM_ACCOUNT;
}
}
- newprot = protection_map[newflags & 0xf];
-
/*
* First try to merge with previous and/or next vma.
*/
pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
*pprev = vma_merge(mm, *pprev, start, end, newflags,
- vma->vm_file, pgoff, vma_policy(vma));
+ vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma));
if (*pprev) {
vma = *pprev;
goto success;
}
+ *pprev = vma;
+
if (start != vma->vm_start) {
error = split_vma(mm, vma, start, 1);
if (error)
goto fail;
}
- /*
- * Unless it returns an error, this function always sets *pprev to
- * the first vma for which vma->vm_end >= end.
- */
- *pprev = vma;
if (end != vma->vm_end) {
error = split_vma(mm, vma, end, 0);
* held in write mode.
*/
vma->vm_flags = newflags;
- vma->vm_page_prot = newprot;
- change_protection(vma, start, end, newprot);
+ vma->vm_page_prot = pgprot_modify(vma->vm_page_prot,
+ vm_get_page_prot(newflags));
+
+ if (vma_wants_writenotify(vma)) {
+ vma->vm_page_prot = vm_get_page_prot(newflags & ~VM_SHARED);
+ dirty_accountable = 1;
+ }
+
+ mmu_notifier_invalidate_range_start(mm, start, end);
+ if (is_vm_hugetlb_page(vma))
+ hugetlb_change_protection(vma, start, end, vma->vm_page_prot);
+ else
+ change_protection(vma, start, end, vma->vm_page_prot, dirty_accountable);
+ mmu_notifier_invalidate_range_end(mm, start, end);
+ vm_stat_account(mm, oldflags, vma->vm_file, -nrpages);
+ vm_stat_account(mm, newflags, vma->vm_file, nrpages);
+ perf_event_mmap(vma);
return 0;
fail:
return error;
}
-asmlinkage long
-sys_mprotect(unsigned long start, size_t len, unsigned long prot)
+SYSCALL_DEFINE3(mprotect, unsigned long, start, size_t, len,
+ unsigned long, prot)
{
- unsigned long vm_flags, nstart, end, tmp;
+ unsigned long vm_flags, nstart, end, tmp, reqprot;
struct vm_area_struct *vma, *prev;
int error = -EINVAL;
const int grows = prot & (PROT_GROWSDOWN|PROT_GROWSUP);
if (start & ~PAGE_MASK)
return -EINVAL;
+ if (!len)
+ return 0;
len = PAGE_ALIGN(len);
end = start + len;
- if (end < start)
+ if (end <= start)
return -ENOMEM;
- if (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM))
+ if (!arch_validate_prot(prot))
return -EINVAL;
- if (end == start)
- return 0;
+
+ reqprot = prot;
+ /*
+ * Does the application expect PROT_READ to imply PROT_EXEC:
+ */
+ if ((prot & PROT_READ) && (current->personality & READ_IMPLIES_EXEC))
+ prot |= PROT_EXEC;
vm_flags = calc_vm_prot_bits(prot);
down_write(¤t->mm->mmap_sem);
- vma = find_vma_prev(current->mm, start, &prev);
+ vma = find_vma(current->mm, start);
error = -ENOMEM;
if (!vma)
goto out;
+ prev = vma->vm_prev;
if (unlikely(grows & PROT_GROWSDOWN)) {
if (vma->vm_start >= end)
goto out;
prev = vma;
for (nstart = start ; ; ) {
- unsigned int newflags;
+ unsigned long newflags;
/* 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));
- if ((newflags & ~(newflags >> 4)) & 0xf) {
+ /* newflags >> 4 shift VM_MAY% in place of VM_% */
+ if ((newflags & ~(newflags >> 4)) & (VM_READ | VM_WRITE | VM_EXEC)) {
error = -EACCES;
goto out;
}
- error = security_file_mprotect(vma, prot);
+ error = security_file_mprotect(vma, reqprot, prot);
if (error)
goto out;
projects / linux-flexiantxendom0-3.2.10.git / blobdiff