Commit 05f9ca83 authored by David S. Miller's avatar David S. Miller
Browse files

[SPARC64]: Randomize mm->mmap_base when PF_RANDOMIZE is set. 



Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent d61e16df

arch/sparc64/kernel/sys_sparc.c

+14 −2
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ 
#include <linux/syscalls.h>

#include <linux/ipc.h>

#include <linux/personality.h>

#include <linux/random.h>



#include <asm/uaccess.h>

#include <asm/ipc.h>
@@ -358,6 +359,17 @@ unsigned long get_fb_unmapped_area(struct file *filp, unsigned long orig_addr, u 
/* Essentially the same as PowerPC... */

void arch_pick_mmap_layout(struct mm_struct *mm)

{

	unsigned long random_factor = 0UL;



	if (current->flags & PF_RANDOMIZE) {

		random_factor = get_random_int();

		if (test_thread_flag(TIF_32BIT))

			random_factor &= ((1 * 1024 * 1024) - 1);

		else

			random_factor = ((random_factor << PAGE_SHIFT) &

					 0xffffffffUL);

	}



	/*

	 * Fall back to the standard layout if the personality

	 * bit is set, or if the expected stack growth is unlimited:
@@ -366,7 +378,7 @@ void arch_pick_mmap_layout(struct mm_struct *mm) 
	    (current->personality & ADDR_COMPAT_LAYOUT) ||

	    current->signal->rlim[RLIMIT_STACK].rlim_cur == RLIM_INFINITY ||

	    sysctl_legacy_va_layout) {

		mm->mmap_base = TASK_UNMAPPED_BASE;

		mm->mmap_base = TASK_UNMAPPED_BASE + random_factor;

		mm->get_unmapped_area = arch_get_unmapped_area;

		mm->unmap_area = arch_unmap_area;

	} else {
@@ -380,7 +392,7 @@ void arch_pick_mmap_layout(struct mm_struct *mm) 
		if (gap > (task_size / 6 * 5))

			gap = (task_size / 6 * 5);



		mm->mmap_base = task_size - (gap & PAGE_MASK);

		mm->mmap_base = PAGE_ALIGN(task_size - gap - random_factor);

		mm->get_unmapped_area = arch_get_unmapped_area_topdown;

		mm->unmap_area = arch_unmap_area_topdown;

	}