parisc: add flexible mmap memory layout support

index ad2b503..369f237 100644
@@ -348,4 +348,11 @@ struct pt_regs;	/* forward declaration... */
 
 #define ELF_HWCAP	0
 
+/* Stack randomization: 1GB for 64bit, 8MB for 32bit */
+#define STACK_RND_MASK (is_32bit_task() ? 0x7ff : 0x3fffff)
+
+struct mm_struct;
+extern unsigned long arch_randomize_brk(struct mm_struct *);
+#define arch_randomize_brk arch_randomize_brk
+
 #endif

index 34899b5..22b89d1 100644
@@ -511,6 +511,7 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr,
 /* We provide our own get_unmapped_area to provide cache coherency */
 
 #define HAVE_ARCH_UNMAPPED_AREA
+#define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
 
 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR

index cc2290a..198a86f 100644
@@ -30,6 +30,8 @@
 #endif
 #define current_text_addr() ({ void *pc; current_ia(pc); pc; })
 
+#define HAVE_ARCH_PICK_MMAP_LAYOUT
+
 #define TASK_SIZE_OF(tsk)       ((tsk)->thread.task_size)
 #define TASK_SIZE	        TASK_SIZE_OF(current)
 #define TASK_UNMAPPED_BASE      (current->thread.map_base)

index d5f97ea..4b9b10c 100644
@@ -76,6 +76,16 @@ struct thread_info {
 #define _TIF_SYSCALL_TRACE_MASK (_TIF_SYSCALL_TRACE | _TIF_SINGLESTEP |	\
 				 _TIF_BLOCKSTEP | _TIF_SYSCALL_AUDIT)
 
+#ifdef CONFIG_64BIT
+# ifdef CONFIG_COMPAT
+#  define is_32bit_task()	(test_thread_flag(TIF_32BIT))
+# else
+#  define is_32bit_task()	(0)
+# endif
+#else
+# define is_32bit_task()	(1)
+#endif
+
 #endif /* __KERNEL__ */
 
 #endif /* _ASM_PARISC_THREAD_INFO_H */

index 55f92b6..0bbbf0d 100644
@@ -13,7 +13,7 @@
  *    Copyright (C) 2000 Grant Grundler <grundler with parisc-linux.org>
  *    Copyright (C) 2001 Alan Modra <amodra at parisc-linux.org>
  *    Copyright (C) 2001-2002 Ryan Bradetich <rbrad at parisc-linux.org>
- *    Copyright (C) 2001-2007 Helge Deller <deller at parisc-linux.org>
+ *    Copyright (C) 2001-2014 Helge Deller <[email protected]>
  *    Copyright (C) 2002 Randolph Chung <tausq with parisc-linux.org>
  *
  *

@@ -49,6 +49,7 @@
 #include <linux/kallsyms.h>
 #include <linux/uaccess.h>
 #include <linux/rcupdate.h>
+#include <linux/random.h>
 
 #include <asm/io.h>
 #include <asm/asm-offsets.h>

@@ -286,3 +287,21 @@ void *dereference_function_descriptor(void *ptr)
 	return ptr;
 }
 #endif
+
+static inline unsigned long brk_rnd(void)
+{
+	/* 8MB for 32bit, 1GB for 64bit */
+	if (is_32bit_task())
+		return (get_random_int() & 0x7ffUL) << PAGE_SHIFT;
+	else
+		return (get_random_int() & 0x3ffffUL) << PAGE_SHIFT;
+}
+
+unsigned long arch_randomize_brk(struct mm_struct *mm)
+{
+	unsigned long ret = PAGE_ALIGN(mm->brk + brk_rnd());
+
+	if (ret < mm->brk)
+		return mm->brk;
+	return ret;
+}

286 lines not on this page · raw message

index e1529b4..a648162 100644
@@ -659,6 +659,9 @@ int setup_arg_pages(struct linux_binprm *bprm,
 	if (stack_base > (1 << 30))
 		stack_base = 1 << 30;
 
+	/* add some more stack size for stack randomization */
+	stack_base += STACK_RND_MASK + 1;
+
 	/* Make sure we didn't let the argument array grow too large. */
 	if (vma->vm_end - vma->vm_start > stack_base)
 		return -ENOMEM;