[v14,18/22] selftests/vm: associate key on a mapped page and detect write violation

Commit Message

Ram Pai July 17, 2018, 1:49 p.m. UTC

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

cc: Dave Hansen <[e-mail]>
cc: Florian Weimer <[e-mail]>
Signed-off-by: Ram Pai <[e-mail]>
Acked-by: Dave Hansen <[e-mail]>
---
 tools/testing/selftests/vm/protection_keys.c |   12 ++++++++++++
 1 files changed, 12 insertions(+), 0 deletions(-)

Patch

diff --git a/tools/testing/selftests/vm/protection_keys.c b/tools/testing/selftests/vm/protection_keys.c
index d41b2dc..59f6f33 100644
--- a/tools/testing/selftests/vm/protection_keys.c
+++ b/tools/testing/selftests/vm/protection_keys.c
@@ -1038,6 +1038,17 @@  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);
@@ -1417,6 +1428,7 @@  void test_mprotect_pkey_on_unsupported_cpu(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,