fedora core 6 1.2949 + vserver 2.2.0

[linux-2.6.git] / arch / i386 / mm / mmap.c

diff --git a/arch/i386/mm/mmap.c b/arch/i386/mm/mmap.c
index a6270ee..356926d 100644 (file)
--- a/arch/i386/mm/mmap.c
+++ b/arch/i386/mm/mmap.c
@@ -26,6 +26,7 @@
 
 #include <linux/personality.h>
 #include <linux/mm.h>
+#include <linux/random.h>
 
 /*
  * Top of mmap area (just below the process stack).
@@ -37,14 +38,18 @@
 
 static inline unsigned long mmap_base(struct mm_struct *mm)
 {
-       unsigned long gap = current->rlim[RLIMIT_STACK].rlim_cur;
+       unsigned long gap = current->signal->rlim[RLIMIT_STACK].rlim_cur;
+       unsigned long random_factor = 0;
+
+       if (current->flags & PF_RANDOMIZE)
+               random_factor = get_random_int() % (1024*1024);
 
        if (gap < MIN_GAP)
                gap = MIN_GAP;
        else if (gap > MAX_GAP)
                gap = MAX_GAP;
 
-       return TASK_SIZE - (gap & PAGE_MASK);
+       return PAGE_ALIGN(TASK_SIZE - gap - random_factor);
 }
 
 /*
@@ -57,15 +62,17 @@ void arch_pick_mmap_layout(struct mm_struct *mm)
         * Fall back to the standard layout if the personality
         * bit is set, or if the expected stack growth is unlimited:
         */
-       if (sysctl_legacy_va_layout ||
+       if (!(2 & exec_shield) && (sysctl_legacy_va_layout ||
                        (current->personality & ADDR_COMPAT_LAYOUT) ||
-                       current->rlim[RLIMIT_STACK].rlim_cur == RLIM_INFINITY) {
+                       current->signal->rlim[RLIMIT_STACK].rlim_cur == RLIM_INFINITY)) {
                mm->mmap_base = TASK_UNMAPPED_BASE;
                mm->get_unmapped_area = arch_get_unmapped_area;
                mm->unmap_area = arch_unmap_area;
        } else {
                mm->mmap_base = mmap_base(mm);
                mm->get_unmapped_area = arch_get_unmapped_area_topdown;
+               if (!(current->personality & READ_IMPLIES_EXEC))
+                       mm->get_unmapped_exec_area = arch_get_unmapped_exec_area;
                mm->unmap_area = arch_unmap_area_topdown;
        }
 }