X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=arch%2Fi386%2Fmm%2Fmmap.c;h=356926d13491e6e4977984a8a7d1f0db7c70e7f7;hb=43bc926fffd92024b46cafaf7350d669ba9ca884;hp=a6270ee14323a729043e8da89bee98b1ecc20b96;hpb=c7b5ebbddf7bcd3651947760f423e3783bbe6573;p=linux-2.6.git

diff --git a/arch/i386/mm/mmap.c b/arch/i386/mm/mmap.c
index a6270ee14..356926d13 100644
--- 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;
 	}
 }