This is a note to let you know that I've just added the patch titled
selftests/x86/ldt_get: Add a few additional tests for limits
to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
selftests-x86-ldt_get-add-a-few-additional-tests-for-limits.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Wed Dec 6 18:04:41 CET 2017
From: Andy Lutomirski <luto@xxxxxxxxxx>
Date: Sat, 4 Nov 2017 04:19:52 -0700
Subject: selftests/x86/ldt_get: Add a few additional tests for limits
From: Andy Lutomirski <luto@xxxxxxxxxx>
[ Upstream commit fec8f5ae1715a01c72ad52cb2ecd8aacaf142302 ]
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@xxxxxxxxxx>
Cc: Borislav Petkov <bpetkov@xxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/5601c15ea9b3113d288953fd2838b18bedf6bc67.1509794321.git.luto@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
tools/testing/selftests/x86/ldt_gdt.c | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)
--- a/tools/testing/selftests/x86/ldt_gdt.c
+++ b/tools/testing/selftests/x86/ldt_gdt.c
@@ -367,9 +367,24 @@ 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);
}
Patches currently in stable-queue which might be from luto@xxxxxxxxxx are
queue-4.14/selftests-x86-ldt_get-add-a-few-additional-tests-for-limits.patch
queue-4.14/selftests-x86-ldt_gdt-robustify-against-set_thread_area-and-lar-oddities.patch
queue-4.14/x86-entry-use-syscall_define-macros-for-sys_modify_ldt.patch