From a8bd6ea3b4d35b5162c21de2bfbca9e7860814ca Mon Sep 17 00:00:00 2001
From: Alexander Popov <alex.popov@linux.com>
Date: Mon, 19 Dec 2016 16:23:06 -0800
Subject: [PATCH] UPSTREAM: arm64: setup: introduce kaslr_offset()

Introduce kaslr_offset() similar to x86_64 to fix kcov.

[ Updated by Will Deacon ]

Link: http://lkml.kernel.org/r/1481417456-28826-2-git-send-email-alex.popov@linux.com
Signed-off-by: Alexander Popov <alex.popov@linux.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Jon Masters <jcm@redhat.com>
Cc: David Daney <david.daney@cavium.com>
Cc: Ganapatrao Kulkarni <gkulkarni@caviumnetworks.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Nicolai Stange <nicstange@gmail.com>
Cc: James Morse <james.morse@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Popov <alex.popov@linux.com>
Cc: syzkaller <syzkaller@googlegroups.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Bug: 64145065
(cherry-picked from 7ede8665f27cde7da69e8b2fbeaa1ed0664879c5)
Change-Id: I9f013afed7f60d2280bb36ce3ba14d8c5515ddb1
Signed-off-by: Paul Lawrence <paullawrence@google.com>
---
 arch/arm64/include/asm/memory.h | 5 +++++
 arch/arm64/kernel/setup.c       | 8 ++++----
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index 915b2422d9d0..279978e1a070 100644
--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h
@@ -148,6 +148,11 @@ extern u64			kimage_vaddr;
 /* the offset between the kernel virtual and physical mappings */
 extern u64			kimage_voffset;
 
+static inline unsigned long kaslr_offset(void)
+{
+	return kimage_vaddr - KIMAGE_VADDR;
+}
+
 /*
  * Allow all memory at the discovery stage. We will clip it later.
  */
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index 09e5ca0226b3..e29a62deeb6c 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -413,11 +413,11 @@ subsys_initcall(topology_init);
 static int dump_kernel_offset(struct notifier_block *self, unsigned long v,
 			      void *p)
 {
-	u64 const kaslr_offset = kimage_vaddr - KIMAGE_VADDR;
+	const unsigned long offset = kaslr_offset();
 
-	if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && kaslr_offset > 0) {
-		pr_emerg("Kernel Offset: 0x%llx from 0x%lx\n",
-			 kaslr_offset, KIMAGE_VADDR);
+	if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && offset > 0) {
+		pr_emerg("Kernel Offset: 0x%lx from 0x%lx\n",
+			 offset, KIMAGE_VADDR);
 	} else {
 		pr_emerg("Kernel Offset: disabled\n");
 	}