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From:   Ram Pai <linuxram@us.ibm.com>
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Subject: [PATCH v12 18/22] selftests/vm: associate key on a mapped page and detect write violation
Date:   Wed, 21 Feb 2018 17:55:37 -0800
Message-Id: <1519264541-7621-19-git-send-email-linuxram@us.ibm.com>
In-Reply-To: <1519264541-7621-1-git-send-email-linuxram@us.ibm.com>
References: <1519264541-7621-1-git-send-email-linuxram@us.ibm.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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>
---
 tools/testing/selftests/vm/protection_keys.c |   12 ++++++++++++
 1 files changed, 12 insertions(+), 0 deletions(-)

diff --git a/tools/testing/selftests/vm/protection_keys.c b/tools/testing/selftests/vm/protection_keys.c
index dba9162..b685e26 100644
--- a/tools/testing/selftests/vm/protection_keys.c
+++ b/tools/testing/selftests/vm/protection_keys.c
@@ -1034,6 +1034,17 @@ 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);
@@ -1330,6 +1341,7 @@ 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,
-- 
1.7.1