releases/4.8.5/arm64-kaslr-fix-breakage-with-config_modversions-y.patch

   1 From 9c0e83c371cf4696926c95f9c8c77cd6ea803426 Mon Sep 17 00:00:00 2001
   2 From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
   3 Date: Thu, 13 Oct 2016 17:42:09 +0100
   4 Subject: arm64: kaslr: fix breakage with CONFIG_MODVERSIONS=y
   5
   6 From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
   7
   8 commit 9c0e83c371cf4696926c95f9c8c77cd6ea803426 upstream.
   9
  10 As it turns out, the KASLR code breaks CONFIG_MODVERSIONS, since the
  11 kcrctab has an absolute address field that is relocated at runtime
  12 when the kernel offset is randomized.
  13
  14 This has been fixed already for PowerPC in the past, so simply wire up
  15 the existing code dealing with this issue.
  16
  17 Fixes: f80fb3a3d508 ("arm64: add support for kernel ASLR")
  18 Tested-by: Timur Tabi <timur@codeaurora.org>
  19 Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
  20 Signed-off-by: Will Deacon <will.deacon@arm.com>
  21 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  22
  23 ---
  24  arch/arm64/include/asm/module.h |    5 +++++
  25  1 file changed, 5 insertions(+)
  26
  27 --- a/arch/arm64/include/asm/module.h
  28 +++ b/arch/arm64/include/asm/module.h
  29 @@ -17,6 +17,7 @@
  30  #define __ASM_MODULE_H
  31
  32  #include <asm-generic/module.h>
  33 +#include <asm/memory.h>
  34
  35  #define MODULE_ARCH_VERMAGIC   "aarch64"
  36
  37 @@ -32,6 +33,10 @@ u64 module_emit_plt_entry(struct module
  38                           Elf64_Sym *sym);
  39
  40  #ifdef CONFIG_RANDOMIZE_BASE
  41 +#ifdef CONFIG_MODVERSIONS
  42 +#define ARCH_RELOCATES_KCRCTAB
  43 +#define reloc_start            (kimage_vaddr - KIMAGE_VADDR)
  44 +#endif
  45  extern u64 module_alloc_base;
  46  #else
  47  #define module_alloc_base      ((u64)_etext - MODULES_VSIZE)