#include <linux/mount.h>
#include <linux/mempolicy.h>
#include <linux/rmap.h>
+#include <linux/random.h>
#include <asm/uaccess.h>
#include <asm/cacheflush.h>
int accountable = 1;
unsigned long charged = 0;
+ /*
+ * Does the application expect PROT_READ to imply PROT_EXEC:
+ */
+ if (unlikely((prot & PROT_READ) &&
+ (current->personality & READ_IMPLIES_EXEC)))
+ prot |= PROT_EXEC;
+
if (file) {
if (is_file_hugepages(file))
accountable = 0;
/* Obtain the address to map to. we verify (or select) it and ensure
* that it represents a valid section of the address space.
*/
- addr = get_unmapped_area(file, addr, len, pgoff, flags, prot & PROT_EXEC);
+ addr = get_unmapped_area_prot(file, addr, len, pgoff, flags, prot & PROT_EXEC);
if (addr & ~PAGE_MASK)
return addr;
* This function "knows" that -ENOMEM has the bits set.
*/
#ifndef HAVE_ARCH_UNMAPPED_AREA
-static inline unsigned long
+unsigned long
arch_get_unmapped_area(struct file *filp, unsigned long addr,
- unsigned long len, unsigned long pgoff, unsigned long flags, unsigned long exec)
+ unsigned long len, unsigned long pgoff, unsigned long flags)
{
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
addr = vma->vm_end;
}
}
-#else
-extern unsigned long
-arch_get_unmapped_area(struct file *, unsigned long, unsigned long,
- unsigned long, unsigned long, unsigned long);
#endif
+void arch_unmap_area(struct vm_area_struct *area)
+{
+ /*
+ * Is this a new hole at the lowest possible address?
+ */
+ if (area->vm_start >= TASK_UNMAPPED_BASE &&
+ area->vm_start < area->vm_mm->free_area_cache)
+ area->vm_mm->free_area_cache = area->vm_start;
+}
+
+/*
+ * This mmap-allocator allocates new areas top-down from below the
+ * stack's low limit (the base):
+ */
unsigned long
-get_unmapped_area(struct file *file, unsigned long addr, unsigned long len,
- unsigned long pgoff, unsigned long flags, unsigned long exec)
+arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
+ const unsigned long len, const unsigned long pgoff,
+ const unsigned long flags)
+{
+ struct vm_area_struct *vma, *prev_vma;
+ struct mm_struct *mm = current->mm;
+ unsigned long base = mm->mmap_base, addr = addr0;
+ int first_time = 1;
+
+ /* requested length too big for entire address space */
+ if (len > TASK_SIZE)
+ return -ENOMEM;
+
+ /* dont allow allocations above current base */
+ if (mm->free_area_cache > base)
+ mm->free_area_cache = base;
+
+ /* requesting a specific address */
+ if (addr) {
+ addr = PAGE_ALIGN(addr);
+ vma = find_vma(mm, addr);
+ if (TASK_SIZE - len >= addr &&
+ (!vma || addr + len <= vma->vm_start))
+ return addr;
+ }
+
+try_again:
+ /* make sure it can fit in the remaining address space */
+ if (mm->free_area_cache < len)
+ goto fail;
+
+ /* either no address requested or cant fit in requested address hole */
+ addr = (mm->free_area_cache - len) & PAGE_MASK;
+ do {
+ /*
+ * Lookup failure means no vma is above this address,
+ * i.e. return with success:
+ */
+ if (!(vma = find_vma_prev(mm, addr, &prev_vma)))
+ return addr;
+
+ /*
+ * new region fits between prev_vma->vm_end and
+ * vma->vm_start, use it:
+ */
+ if (addr+len <= vma->vm_start &&
+ (!prev_vma || (addr >= prev_vma->vm_end)))
+ /* remember the address as a hint for next time */
+ return (mm->free_area_cache = addr);
+ else
+ /* pull free_area_cache down to the first hole */
+ if (mm->free_area_cache == vma->vm_end)
+ mm->free_area_cache = vma->vm_start;
+
+ /* try just below the current vma->vm_start */
+ addr = vma->vm_start-len;
+ } while (len <= vma->vm_start);
+
+fail:
+ /*
+ * if hint left us with no space for the requested
+ * mapping then try again:
+ */
+ if (first_time) {
+ mm->free_area_cache = base;
+ first_time = 0;
+ goto try_again;
+ }
+ /*
+ * A failed mmap() very likely causes application failure,
+ * so fall back to the bottom-up function here. This scenario
+ * can happen with large stack limits and large mmap()
+ * allocations.
+ */
+ mm->free_area_cache = TASK_UNMAPPED_BASE;
+ addr = arch_get_unmapped_area(filp, addr0, len, pgoff, flags);
+ /*
+ * Restore the topdown base:
+ */
+ mm->free_area_cache = base;
+
+ return addr;
+}
+
+void arch_unmap_area_topdown(struct vm_area_struct *area)
+{
+ /*
+ * Is this a new hole at the highest possible address?
+ */
+ if (area->vm_end > area->vm_mm->free_area_cache)
+ area->vm_mm->free_area_cache = area->vm_end;
+}
+
+
+unsigned long
+get_unmapped_area_prot(struct file *file, unsigned long addr, unsigned long len,
+ unsigned long pgoff, unsigned long flags, int exec)
{
if (flags & MAP_FIXED) {
unsigned long ret;
return file->f_op->get_unmapped_area(file, addr, len,
pgoff, flags);
- return arch_get_unmapped_area(file, addr, len, pgoff, flags, exec);
+ if (exec && current->mm->get_unmapped_exec_area)
+ return current->mm->get_unmapped_exec_area(file, addr, len, pgoff, flags);
+ else
+ return current->mm->get_unmapped_area(file, addr, len, pgoff, flags);
}
-EXPORT_SYMBOL(get_unmapped_area);
+EXPORT_SYMBOL(get_unmapped_area_prot);
+
+
+#define SHLIB_BASE 0x00111000
+
+unsigned long arch_get_unmapped_exec_area(struct file *filp, unsigned long addr0,
+ unsigned long len0, unsigned long pgoff, unsigned long flags)
+{
+ unsigned long addr = addr0, len = len0;
+ struct mm_struct *mm = current->mm;
+ struct vm_area_struct *vma;
+ unsigned long tmp;
+
+ if (len > TASK_SIZE)
+ return -ENOMEM;
+
+ if (!addr && !(flags & MAP_FIXED))
+ addr = randomize_range(SHLIB_BASE, 0x01000000, len);
+
+ if (addr) {
+ addr = PAGE_ALIGN(addr);
+ vma = find_vma(mm, addr);
+ if (TASK_SIZE - len >= addr &&
+ (!vma || addr + len <= vma->vm_start)) {
+ return addr;
+ }
+ }
+
+ addr = SHLIB_BASE;
+
+ for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
+ /* At this point: (!vma || addr < vma->vm_end). */
+ if (TASK_SIZE - len < addr) {
+ return -ENOMEM;
+ }
+ if (!vma || addr + len <= vma->vm_start) {
+ /*
+ * Must not let a PROT_EXEC mapping get into the
+ * brk area:
+ */
+ if (addr + len > mm->brk)
+ goto failed;
+
+ /*
+ * Up until the brk area we randomize addresses
+ * as much as possible:
+ */
+ if (addr >= 0x01000000) {
+ tmp = randomize_range(0x01000000, mm->brk, len);
+ vma = find_vma(mm, tmp);
+ if (TASK_SIZE - len >= tmp &&
+ (!vma || tmp + len <= vma->vm_start))
+ return tmp;
+ }
+ /*
+ * Ok, randomization didnt work out - return
+ * the result of the linear search:
+ */
+ return addr;
+ }
+ addr = vma->vm_end;
+ }
+
+failed:
+ return current->mm->get_unmapped_area(filp, addr0, len0, pgoff, flags);
+}
+
+
/* Look up the first VMA which satisfies addr < vm_end, NULL if none. */
struct vm_area_struct * find_vma(struct mm_struct * mm, unsigned long addr)
static void unmap_vma(struct mm_struct *mm, struct vm_area_struct *area)
{
size_t len = area->vm_end - area->vm_start;
- unsigned long old_end = area->vm_end;
// area->vm_mm->total_vm -= len >> PAGE_SHIFT;
vx_vmpages_sub(area->vm_mm, len >> PAGE_SHIFT);
if (area->vm_flags & VM_LOCKED)
// area->vm_mm->locked_vm -= len >> PAGE_SHIFT;
vx_vmlocked_sub(area->vm_mm, len >> PAGE_SHIFT);
- /*
- * Is this a new hole at the lowest possible address?
- */
- if (area->vm_start >= TASK_UNMAPPED_BASE &&
- area->vm_start < area->vm_mm->free_area_cache)
- area->vm_mm->free_area_cache = area->vm_start;
- /*
- * Is this a new hole at the highest possible address?
- */
- if (area->vm_start > area->vm_mm->non_executable_cache)
- area->vm_mm->non_executable_cache = area->vm_start;
+ area->vm_mm->unmap_area(area);
remove_vm_struct(area);
- if (unlikely(area->vm_flags & VM_EXEC))
- arch_remove_exec_range(mm, old_end);
}
/*
git://git.onelab.eu / linux-2.6.git / blobdiff