[PATCH v15 18/23] selftests/vm/pkeys: Detect write violation on a mapped access-denied-key page

[Sandipan Das]

From: Ram Pai <linux...@us.ibm.com>

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

cc: Dave Hansen <dave.han...@intel.com>
cc: Florian Weimer <fwei...@redhat.com>
Signed-off-by: Ram Pai <linux...@us.ibm.com>
Acked-by: Dave Hansen <dave.han...@intel.com>
Signed-off-by: Sandipan Das <sandi...@linux.ibm.com>
---
 tools/testing/selftests/vm/protection_keys.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/tools/testing/selftests/vm/protection_keys.c 
b/tools/testing/selftests/vm/protection_keys.c
index ff207b765afd..176625ded549 100644
--- a/tools/testing/selftests/vm/protection_keys.c
+++ b/tools/testing/selftests/vm/protection_keys.c
@@ -1026,6 +1026,18 @@ void test_write_of_access_disabled_region(int *ptr, u16 
pkey)
        *ptr = __LINE__;
        expected_pkey_fault(pkey);
 }
+
+void test_write_of_access_disabled_region_with_page_already_mapped(int *ptr,
+                       u16 pkey)
+{
+       *ptr = __LINE__;
+       dprintf1("disabling access; after accessing the page, "
+               " to PKEY[%02d], doing write\n", pkey);
+       pkey_access_deny(pkey);
+       *ptr = __LINE__;
+       expected_pkey_fault(pkey);
+}
+
 void test_kernel_write_of_access_disabled_region(int *ptr, u16 pkey)
 {
        int ret;
@@ -1422,6 +1434,7 @@ void (*pkey_tests[])(int *ptr, u16 pkey) = {
        test_write_of_write_disabled_region,
        test_write_of_write_disabled_region_with_page_already_mapped,
        test_write_of_access_disabled_region,
+       test_write_of_access_disabled_region_with_page_already_mapped,
        test_kernel_write_of_access_disabled_region,
        test_kernel_write_of_write_disabled_region,
        test_kernel_gup_of_access_disabled_region,
-- 
2.17.1