Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Will Deacon:

 - virt_to_page/page_address optimisations

 - support for NUMA systems described using device-tree

 - support for hibernate/suspend-to-disk

 - proper support for maxcpus= command line parameter

 - detection and graceful handling of AArch64-only CPUs

 - miscellaneous cleanups and non-critical fixes

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (92 commits)
  arm64: do not enforce strict 16 byte alignment to stack pointer
  arm64: kernel: Fix incorrect brk randomization
  arm64: cpuinfo: Missing NULL terminator in compat_hwcap_str
  arm64: secondary_start_kernel: Remove unnecessary barrier
  arm64: Ensure pmd_present() returns false after pmd_mknotpresent()
  arm64: Replace hard-coded values in the pmd/pud_bad() macros
  arm64: Implement pmdp_set_access_flags() for hardware AF/DBM
  arm64: Fix typo in the pmdp_huge_get_and_clear() definition
  arm64: mm: remove unnecessary EXPORT_SYMBOL_GPL
  arm64: always use STRICT_MM_TYPECHECKS
  arm64: kvm: Fix kvm teardown for systems using the extended idmap
  arm64: kaslr: increase randomization granularity
  arm64: kconfig: drop CONFIG_RTC_LIB dependency
  arm64: make ARCH_SUPPORTS_DEBUG_PAGEALLOC depend on !HIBERNATION
  arm64: hibernate: Refuse to hibernate if the boot cpu is offline
  arm64: kernel: Add support for hibernate/suspend-to-disk
  PM / Hibernate: Call flush_icache_range() on pages restored in-place
  arm64: Add new asm macro copy_page
  arm64: Promote KERNEL_START/KERNEL_END definitions to a header file
  arm64: kernel: Include _AC definition in page.h
  ...

1 files changed, 8 insertions, 10 deletions

diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index 8062482..48eea68 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -265,9 +265,6 @@ int copy_thread(unsigned long clone_flags, unsigned long stack_start,
 		if (stack_start) {
 			if (is_compat_thread(task_thread_info(p)))
 				childregs->compat_sp = stack_start;
-			/* 16-byte aligned stack mandatory on AArch64 */
-			else if (stack_start & 15)
-				return -EINVAL;
 			else
 				childregs->sp = stack_start;
 		}
@@ -382,13 +379,14 @@ unsigned long arch_align_stack(unsigned long sp)
 	return sp & ~0xf;
 }
 
-static unsigned long randomize_base(unsigned long base)
-{
-	unsigned long range_end = base + (STACK_RND_MASK << PAGE_SHIFT) + 1;
-	return randomize_range(base, range_end, 0) ? : base;
-}
-
 unsigned long arch_randomize_brk(struct mm_struct *mm)
 {
-	return randomize_base(mm->brk);
+	unsigned long range_end = mm->brk;
+
+	if (is_compat_task())
+		range_end += 0x02000000;
+	else
+		range_end += 0x40000000;
+
+	return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
 }