#include <linux/personality.h>
#include <linux/mm.h>
+#include <linux/random.h>
/*
* Top of mmap area (just below the process stack).
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);
}
/*
* 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 || (current->personality & ADDR_COMPAT_LAYOUT) ||
- current->rlim[RLIMIT_STACK].rlim_cur == RLIM_INFINITY) {
+ if (!(2 & exec_shield) && (sysctl_legacy_va_layout ||
+ (current->personality & ADDR_COMPAT_LAYOUT) ||
+ 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;
- mm->get_unmapped_exec_area = arch_get_unmapped_exec_area;
+ if (!(current->personality & READ_IMPLIES_EXEC))
+ mm->get_unmapped_exec_area = arch_get_unmapped_exec_area;
mm->unmap_area = arch_unmap_area_topdown;
}
}