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 <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Link: http://lkml.kernel.org/r/5601c15ea9b3113d288953fd2838b18bedf6bc67.1509794321.git.luto@kernel.org
Signed-off-by: Ingo Molnar <[email protected]>
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);
}
