queue-4.4/init-initialize-jump-labels-before-command-line-opti.patch

   1 From ac5d3cefba62b94e8d02640f85de9cf7b8a78732 Mon Sep 17 00:00:00 2001
   2 From: Dan Williams <dan.j.williams@intel.com>
   3 Date: Thu, 18 Apr 2019 17:50:44 -0700
   4 Subject: init: initialize jump labels before command line option parsing
   5
   6 [ Upstream commit 6041186a32585fc7a1d0f6cfe2f138b05fdc3c82 ]
   7
   8 When a module option, or core kernel argument, toggles a static-key it
   9 requires jump labels to be initialized early.  While x86, PowerPC, and
  10 ARM64 arrange for jump_label_init() to be called before parse_args(),
  11 ARM does not.
  12
  13   Kernel command line: rdinit=/sbin/init page_alloc.shuffle=1 panic=-1 console=ttyAMA0,115200 page_alloc.shuffle=1
  14   ------------[ cut here ]------------
  15   WARNING: CPU: 0 PID: 0 at ./include/linux/jump_label.h:303
  16   page_alloc_shuffle+0x12c/0x1ac
  17   static_key_enable(): static key 'page_alloc_shuffle_key+0x0/0x4' used
  18   before call to jump_label_init()
  19   Modules linked in:
  20   CPU: 0 PID: 0 Comm: swapper Not tainted
  21   5.1.0-rc4-next-20190410-00003-g3367c36ce744 #1
  22   Hardware name: ARM Integrator/CP (Device Tree)
  23   [<c0011c68>] (unwind_backtrace) from [<c000ec48>] (show_stack+0x10/0x18)
  24   [<c000ec48>] (show_stack) from [<c07e9710>] (dump_stack+0x18/0x24)
  25   [<c07e9710>] (dump_stack) from [<c001bb1c>] (__warn+0xe0/0x108)
  26   [<c001bb1c>] (__warn) from [<c001bb88>] (warn_slowpath_fmt+0x44/0x6c)
  27   [<c001bb88>] (warn_slowpath_fmt) from [<c0b0c4a8>]
  28   (page_alloc_shuffle+0x12c/0x1ac)
  29   [<c0b0c4a8>] (page_alloc_shuffle) from [<c0b0c550>] (shuffle_store+0x28/0x48)
  30   [<c0b0c550>] (shuffle_store) from [<c003e6a0>] (parse_args+0x1f4/0x350)
  31   [<c003e6a0>] (parse_args) from [<c0ac3c00>] (start_kernel+0x1c0/0x488)
  32
  33 Move the fallback call to jump_label_init() to occur before
  34 parse_args().
  35
  36 The redundant calls to jump_label_init() in other archs are left intact
  37 in case they have static key toggling use cases that are even earlier
  38 than option parsing.
  39
  40 Link: http://lkml.kernel.org/r/155544804466.1032396.13418949511615676665.stgit@dwillia2-desk3.amr.corp.intel.com
  41 Signed-off-by: Dan Williams <dan.j.williams@intel.com>
  42 Reported-by: Guenter Roeck <groeck@google.com>
  43 Reviewed-by: Kees Cook <keescook@chromium.org>
  44 Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  45 Cc: Thomas Gleixner <tglx@linutronix.de>
  46 Cc: Mike Rapoport <rppt@linux.ibm.com>
  47 Cc: Russell King <rmk@armlinux.org.uk>
  48 Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
  49 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
  50 Signed-off-by: Sasha Levin <sashal@kernel.org>
  51 ---
  52  init/main.c | 4 ++--
  53  1 file changed, 2 insertions(+), 2 deletions(-)
  54
  55 diff --git a/init/main.c b/init/main.c
  56 index 49926d95442f8..e88c8cdef6a7c 100644
  57 --- a/init/main.c
  58 +++ b/init/main.c
  59 @@ -538,6 +538,8 @@ asmlinkage __visible void __init start_kernel(void)
  60         page_alloc_init();
  61
  62         pr_notice("Kernel command line: %s\n", boot_command_line);
  63 +       /* parameters may set static keys */
  64 +       jump_label_init();
  65         parse_early_param();
  66         after_dashes = parse_args("Booting kernel",
  67                                   static_command_line, __start___param,
  68 @@ -547,8 +549,6 @@ asmlinkage __visible void __init start_kernel(void)
  69                 parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,
  70                            NULL, set_init_arg);
  71
  72 -       jump_label_init();
  73 -
  74         /*
  75          * These use large bootmem allocations and must precede
  76          * kmem_cache_init()
  77 --
  78 2.20.1
  79