[PATCH v18 18/24] selftests/vm/pkeys: Associate key on a mapped page and detect write violation

Sandipan Das
2020-01-30T06:38:11Z

Detect write-violation on a page to which write-disabled
key is associated much after the page is mapped.

cc: Dave Hansen <dave.hansen@intel.com>
cc: Florian Weimer <fweimer@redhat.com>
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
---
tools/testing/selftests/vm/protection_keys.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/tools/testing/selftests/vm/protection_keys.c b/tools/testing/selftests/vm/protection_keys.c
index f65d384ef6a0..cb31a5cdf6d9 100644
--- a/tools/testing/selftests/vm/protection_keys.c
+++ b/tools/testing/selftests/vm/protection_keys.c
@@ -1002,6 +1002,17 @@ void test_read_of_access_disabled_region_with_page_already_mapped(int *ptr,
expected_pkey_fault(pkey);
}

+void test_write_of_write_disabled_region_with_page_already_mapped(int *ptr,
+ u16 pkey)
+{
+ *ptr = __LINE__;
+ dprintf1("disabling write access; after accessing the page, "
+ "to PKEY[%02d], doing write\n", pkey);
+ pkey_write_deny(pkey);
+ *ptr = __LINE__;
+ expected_pkey_fault(pkey);
+}
+
void test_write_of_write_disabled_region(int *ptr, u16 pkey)
{
dprintf1("disabling write access to PKEY[%02d], doing write\n", pkey);
@@ -1410,6 +1421,7 @@ void (*pkey_tests[])(int *ptr, u16 pkey) = {
test_read_of_access_disabled_region,
test_read_of_access_disabled_region_with_page_already_mapped,
test_write_of_write_disabled_region,
+ test_write_of_write_disabled_region_with_page_already_mapped,
test_write_of_access_disabled_region,
test_kernel_write_of_access_disabled_region,
test_kernel_write_of_write_disabled_region,
--
2.17.1