Subject: [PATCH v12 08/22] selftests/vm: clear the bits in shadow reg when a pkey is freed.

From: Ram Pai <[email-masked]>
Date: Wed, 21 Feb 2018 17:55:27 -0800

When a key is freed, the  key  is  no  more  effective.
Clear the bits corresponding to the pkey in the shadow
register. Otherwise  it  will carry some spurious bits
which can trigger false-positive asserts.

cc: Dave Hansen <[email-masked]>
cc: Florian Weimer <[email-masked]>
Signed-off-by: Ram Pai <[email-masked]>
---
 tools/testing/selftests/vm/protection_keys.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/tools/testing/selftests/vm/protection_keys.c b/tools/testing/selftests/vm/protection_keys.c
index ca54a95..aaf9f09 100644
--- a/tools/testing/selftests/vm/protection_keys.c
+++ b/tools/testing/selftests/vm/protection_keys.c
@@ -582,6 +582,9 @@ int alloc_pkey(void)
 int sys_pkey_free(unsigned long pkey)
 {
 	int ret = syscall(SYS_pkey_free, pkey);
+
+	if (!ret)
+		shadow_pkey_reg &= reset_bits(pkey, PKEY_DISABLE_ACCESS);
 	dprintf1("%s(pkey=%ld) syscall ret: %d\n", __func__, pkey, ret);
 	return ret;
 }
-- 
1.7.1