releases/4.9.68/selftests-x86-ldt_get-add-a-few-additional-tests-for-limits.patch

   1 From foo@baz Wed Dec  6 17:39:55 CET 2017
   2 From: Andy Lutomirski <luto@kernel.org>
   3 Date: Sat, 4 Nov 2017 04:19:52 -0700
   4 Subject: selftests/x86/ldt_get: Add a few additional tests for limits
   5
   6 From: Andy Lutomirski <luto@kernel.org>
   7
   8
   9 [ Upstream commit fec8f5ae1715a01c72ad52cb2ecd8aacaf142302 ]
  10
  11 We weren't testing the .limit and .limit_in_pages fields very well.
  12 Add more tests.
  13
  14 This addition seems to trigger the "bits 16:19 are undefined" issue
  15 that was fixed in an earlier patch.  I think that, at least on my
  16 CPU, the high nibble of the limit ends in LAR bits 16:19.
  17
  18 Signed-off-by: Andy Lutomirski <luto@kernel.org>
  19 Cc: Borislav Petkov <bpetkov@suse.de>
  20 Cc: Linus Torvalds <torvalds@linux-foundation.org>
  21 Cc: Peter Zijlstra <peterz@infradead.org>
  22 Cc: Thomas Gleixner <tglx@linutronix.de>
  23 Link: http://lkml.kernel.org/r/5601c15ea9b3113d288953fd2838b18bedf6bc67.1509794321.git.luto@kernel.org
  24 Signed-off-by: Ingo Molnar <mingo@kernel.org>
  25 Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
  26 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  27 ---
  28  tools/testing/selftests/x86/ldt_gdt.c |   17 ++++++++++++++++-
  29  1 file changed, 16 insertions(+), 1 deletion(-)
  30
  31 --- a/tools/testing/selftests/x86/ldt_gdt.c
  32 +++ b/tools/testing/selftests/x86/ldt_gdt.c
  33 @@ -360,9 +360,24 @@ static void do_simple_tests(void)
  34         install_invalid(&desc, false);
  35
  36         desc.seg_not_present = 0;
  37 -       desc.read_exec_only = 0;
  38         desc.seg_32bit = 1;
  39 +       desc.read_exec_only = 0;
  40 +       desc.limit = 0xfffff;
  41 +
  42         install_valid(&desc, AR_DPL3 | AR_TYPE_RWDATA | AR_S | AR_P | AR_DB);
  43 +
  44 +       desc.limit_in_pages = 1;
  45 +
  46 +       install_valid(&desc, AR_DPL3 | AR_TYPE_RWDATA | AR_S | AR_P | AR_DB | AR_G);
  47 +       desc.read_exec_only = 1;
  48 +       install_valid(&desc, AR_DPL3 | AR_TYPE_RODATA | AR_S | AR_P | AR_DB | AR_G);
  49 +       desc.contents = 1;
  50 +       desc.read_exec_only = 0;
  51 +       install_valid(&desc, AR_DPL3 | AR_TYPE_RWDATA_EXPDOWN | AR_S | AR_P | AR_DB | AR_G);
  52 +       desc.read_exec_only = 1;
  53 +       install_valid(&desc, AR_DPL3 | AR_TYPE_RODATA_EXPDOWN | AR_S | AR_P | AR_DB | AR_G);
  54 +
  55 +       desc.limit = 0;
  56         install_invalid(&desc, true);
  57  }
  58