lkml.org 
[lkml]   [2017]   [Nov]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[tip:x86/asm] selftests/x86/ldt_get: Add a few additional tests for limits
Commit-ID:  fec8f5ae1715a01c72ad52cb2ecd8aacaf142302
Gitweb: https://git.kernel.org/tip/fec8f5ae1715a01c72ad52cb2ecd8aacaf142302
Author: Andy Lutomirski <luto@kernel.org>
AuthorDate: Sat, 4 Nov 2017 04:19:52 -0700
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 7 Nov 2017 11:13:43 +0100

selftests/x86/ldt_get: Add a few additional tests for limits

We weren't testing the .limit and .limit_in_pages fields very well.
Add more tests.

This addition seems to trigger the "bits 16:19 are undefined" issue
that was fixed in an earlier patch. I think that, at least on my
CPU, the high nibble of the limit ends in LAR bits 16:19.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/5601c15ea9b3113d288953fd2838b18bedf6bc67.1509794321.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
tools/testing/selftests/x86/ldt_gdt.c | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/x86/ldt_gdt.c b/tools/testing/selftests/x86/ldt_gdt.c
index 3bb42ff..66e5ce5 100644
--- a/tools/testing/selftests/x86/ldt_gdt.c
+++ b/tools/testing/selftests/x86/ldt_gdt.c
@@ -404,9 +404,24 @@ static void do_simple_tests(void)
install_invalid(&desc, false);

desc.seg_not_present = 0;
- desc.read_exec_only = 0;
desc.seg_32bit = 1;
+ desc.read_exec_only = 0;
+ desc.limit = 0xfffff;
+
install_valid(&desc, AR_DPL3 | AR_TYPE_RWDATA | AR_S | AR_P | AR_DB);
+
+ desc.limit_in_pages = 1;
+
+ install_valid(&desc, AR_DPL3 | AR_TYPE_RWDATA | AR_S | AR_P | AR_DB | AR_G);
+ desc.read_exec_only = 1;
+ install_valid(&desc, AR_DPL3 | AR_TYPE_RODATA | AR_S | AR_P | AR_DB | AR_G);
+ desc.contents = 1;
+ desc.read_exec_only = 0;
+ install_valid(&desc, AR_DPL3 | AR_TYPE_RWDATA_EXPDOWN | AR_S | AR_P | AR_DB | AR_G);
+ desc.read_exec_only = 1;
+ install_valid(&desc, AR_DPL3 | AR_TYPE_RODATA_EXPDOWN | AR_S | AR_P | AR_DB | AR_G);
+
+ desc.limit = 0;
install_invalid(&desc, true);
}

\
 
 \ /
  Last update: 2017-11-08 21:03    [W:0.097 / U:0.256 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site