#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 <asm/uaccess.h>
-#include <asm/pgalloc.h>
#include <asm/pgtable.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
}
static inline void
-change_pmd_range(pgd_t *pgd, unsigned long address,
+change_pmd_range(pud_t *pud, unsigned long address,
unsigned long size, pgprot_t newprot)
{
pmd_t * pmd;
unsigned long end;
+ if (pud_none(*pud))
+ return;
+ if (pud_bad(*pud)) {
+ pud_ERROR(*pud);
+ pud_clear(pud);
+ return;
+ }
+ pmd = pmd_offset(pud, address);
+ address &= ~PUD_MASK;
+ end = address + size;
+ if (end > PUD_SIZE)
+ end = PUD_SIZE;
+ do {
+ change_pte_range(pmd, address, end - address, newprot);
+ address = (address + PMD_SIZE) & PMD_MASK;
+ pmd++;
+ } while (address && (address < end));
+}
+
+static inline void
+change_pud_range(pgd_t *pgd, unsigned long address,
+ unsigned long size, pgprot_t newprot)
+{
+ pud_t * pud;
+ unsigned long end;
+
if (pgd_none(*pgd))
return;
if (pgd_bad(*pgd)) {
pgd_clear(pgd);
return;
}
- pmd = pmd_offset(pgd, address);
+ pud = pud_offset(pgd, address);
address &= ~PGDIR_MASK;
end = address + size;
if (end > PGDIR_SIZE)
end = PGDIR_SIZE;
do {
- change_pte_range(pmd, address, end - address, newprot);
- address = (address + PMD_SIZE) & PMD_MASK;
- pmd++;
+ change_pmd_range(pud, address, end - address, newprot);
+ address = (address + PUD_SIZE) & PUD_MASK;
+ pud++;
} while (address && (address < end));
}
change_protection(struct vm_area_struct *vma, unsigned long start,
unsigned long end, pgprot_t newprot)
{
- pgd_t *dir;
- unsigned long beg = start;
+ struct mm_struct *mm = current->mm;
+ pgd_t *pgd;
+ unsigned long beg = start, next;
+ int i;
- dir = pgd_offset(current->mm, start);
+ pgd = pgd_offset(mm, start);
flush_cache_range(vma, beg, end);
- if (start >= end)
- BUG();
- spin_lock(¤t->mm->page_table_lock);
- 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;
-}
-/*
- * Try to merge a vma with the previous flag, return 1 if successful or 0 if it
- * was impossible.
- */
-static int
-mprotect_attempt_merge(struct vm_area_struct *vma, struct vm_area_struct *prev,
- unsigned long end, int newflags)
-{
- struct mm_struct * mm;
-
- if (!prev || !vma)
- return 0;
- mm = vma->vm_mm;
- if (prev->vm_end != vma->vm_start)
- return 0;
- if (!can_vma_merge(prev, newflags))
- return 0;
- if (vma->vm_file || (vma->vm_flags & VM_SHARED))
- return 0;
-
- /*
- * If the whole area changes to the protection of the previous one
- * we can just get rid of it.
- */
- if (end == vma->vm_end) {
- spin_lock(&mm->page_table_lock);
- prev->vm_end = end;
- __vma_unlink(mm, vma, prev);
- spin_unlock(&mm->page_table_lock);
-
- kmem_cache_free(vm_area_cachep, vma);
- mm->map_count--;
- return 1;
- }
-
- /*
- * Otherwise extend it.
- */
+ BUG_ON(start >= end);
spin_lock(&mm->page_table_lock);
- prev->vm_end = end;
- vma->vm_start = end;
+ for (i = pgd_index(start); i <= pgd_index(end-1); i++) {
+ next = (start + PGDIR_SIZE) & PGDIR_MASK;
+ if (next <= start || next > end)
+ next = end;
+ change_pud_range(pgd, start, next - start, newprot);
+ start = next;
+ pgd++;
+ }
+ flush_tlb_range(vma, beg, end);
spin_unlock(&mm->page_table_lock);
- return 1;
}
static 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;
+ unsigned long oldflags = vma->vm_flags;
+ long nrpages = (end - start) >> PAGE_SHIFT;
unsigned long charged = 0;
pgprot_t newprot;
+ pgoff_t pgoff;
int error;
- if (newflags == vma->vm_flags) {
+ if (newflags == oldflags) {
*pprev = vma;
return 0;
}
* a MAP_NORESERVE private mapping to writable will now reserve.
*/
if (newflags & VM_WRITE) {
- if (!(vma->vm_flags & (VM_ACCOUNT|VM_WRITE|VM_SHARED))
- && VM_MAYACCT(vma)) {
- charged = (end - start) >> PAGE_SHIFT;
+ if (!(oldflags & (VM_ACCOUNT|VM_WRITE|VM_SHARED|VM_HUGETLB))) {
+ charged = nrpages;
if (security_vm_enough_memory(charged))
return -ENOMEM;
newflags |= VM_ACCOUNT;
newprot = protection_map[newflags & 0xf];
- if (start == vma->vm_start) {
- /*
- * Try to merge with the previous vma.
- */
- if (mprotect_attempt_merge(vma, *pprev, end, newflags)) {
- vma = *pprev;
- goto success;
- }
- } else {
+ /*
+ * 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->anon_vma, vma->vm_file, pgoff, vma_policy(vma));
+ if (*pprev) {
+ vma = *pprev;
+ goto success;
+ }
+
+ if (start != vma->vm_start) {
error = split_vma(mm, vma, start, 1);
if (error)
goto fail;
goto fail;
}
- spin_lock(&mm->page_table_lock);
+success:
+ /*
+ * 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;
- spin_unlock(&mm->page_table_lock);
-success:
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:
sys_mprotect(unsigned long start, size_t len, unsigned long prot)
{
unsigned long vm_flags, nstart, end, tmp;
- struct vm_area_struct * vma, * next, * prev;
+ struct vm_area_struct *vma, *prev;
int error = -EINVAL;
const int grows = prot & (PROT_GROWSDOWN|PROT_GROWSUP);
prot &= ~(PROT_GROWSDOWN|PROT_GROWSUP);
return -EINVAL;
if (end == start)
return 0;
+ /*
+ * Does the application expect PROT_READ to imply PROT_EXEC:
+ */
+ if (unlikely((prot & PROT_READ) &&
+ (current->personality & READ_IMPLIES_EXEC)))
+ prot |= PROT_EXEC;
vm_flags = calc_vm_prot_bits(prot);
goto out;
}
}
+ if (start > vma->vm_start)
+ prev = vma;
for (nstart = start ; ; ) {
- unsigned int newflags;
- int last = 0;
+ unsigned long newflags;
/* Here we know that vma->vm_start <= nstart < vma->vm_end. */
if (error)
goto out;
- if (vma->vm_end > end) {
- error = mprotect_fixup(vma, &prev, nstart, end, newflags);
- goto out;
- }
- if (vma->vm_end == end)
- last = 1;
-
tmp = vma->vm_end;
- next = vma->vm_next;
+ if (tmp > end)
+ tmp = end;
error = mprotect_fixup(vma, &prev, nstart, tmp, newflags);
if (error)
goto out;
- if (last)
- break;
nstart = tmp;
- vma = next;
+
+ if (nstart < prev->vm_end)
+ nstart = prev->vm_end;
+ if (nstart >= end)
+ goto out;
+
+ vma = prev->vm_next;
if (!vma || vma->vm_start != nstart) {
error = -ENOMEM;
goto out;
}
}
-
- if (next && prev->vm_end == next->vm_start &&
- can_vma_merge(next, prev->vm_flags) &&
- !prev->vm_file && !(prev->vm_flags & VM_SHARED)) {
- spin_lock(&prev->vm_mm->page_table_lock);
- prev->vm_end = next->vm_end;
- __vma_unlink(prev->vm_mm, next, prev);
- spin_unlock(&prev->vm_mm->page_table_lock);
-
- kmem_cache_free(vm_area_cachep, next);
- prev->vm_mm->map_count--;
- }
out:
up_write(¤t->mm->mmap_sem);
return error;
git://git.onelab.eu / linux-2.6.git / blobdiff