[120/127] selftests/vm/pkeys: detect write violation on a mapped access-denied-key page

Commit Message

Andrew Morton June 4, 2020, 11:52 p.m. UTC

From: Ram Pai <[e-mail]>
Subject: selftests/vm/pkeys: detect write violation on a mapped access-denied-key page

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

Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Ram Pai <[e-mail]>
Acked-by: Dave Hansen <[e-mail]>
Signed-off-by: Sandipan Das <[e-mail]>
Cc: Dave Hansen <[e-mail]>
Cc: Florian Weimer <[e-mail]>
Cc: "Desnes A. Nunes do Rosario" <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: Thiago Jung Bauermann <[e-mail]>
Cc: "Aneesh Kumar K.V" <[e-mail]>
Cc: Michael Ellerman <[e-mail]>
Cc: Michal Hocko <[e-mail]>
Cc: Michal Suchanek <[e-mail]>
Cc: Shuah Khan <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
---

 tools/testing/selftests/vm/protection_keys.c |   13 +++++++++++++
 1 file changed, 13 insertions(+)

Patch

--- a/tools/testing/selftests/vm/protection_keys.c~selftests-vm-pkeys-detect-write-violation-on-a-mapped-access-denied-key-page
+++ a/tools/testing/selftests/vm/protection_keys.c
@@ -1027,6 +1027,18 @@  void test_write_of_access_disabled_regio
 	*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;
@@ -1423,6 +1435,7 @@  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,