[SPARC64]: Randomize mm->mmap_base when PF_RANDOMIZE is set. (05f9ca83) · Commits · e / devices / android_kernel_fairphone_FP4

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;
		}