[PATCH v13 10/24] selftests/vm: clear the bits in shadow reg when a pkey is freed.

From: Ram Pai <linuxram@us.ibm.com>
To: shuahkh@osg.samsung.com, linux-kselftest@vger.kernel.org
Cc: mpe@ellerman.id.au, linuxppc-dev@lists.ozlabs.org,
	linux-mm@kvack.org, x86@kernel.org, linux-arch@vger.kernel.org,
	mingo@redhat.com, dave.hansen@intel.com, mhocko@kernel.org,
	bauerman@linux.vnet.ibm.com, linuxram@us.ibm.com,
	fweimer@redhat.com, msuchanek@suse.de,
	aneesh.kumar@linux.vnet.ibm.com
Subject: [PATCH v13 10/24] selftests/vm: clear the bits in shadow reg when a pkey is freed.
Date: Wed, 13 Jun 2018 17:45:01 -0700	[thread overview]
Message-ID: <1528937115-10132-11-git-send-email-linuxram@us.ibm.com> (raw)
In-Reply-To: <1528937115-10132-1-git-send-email-linuxram@us.ibm.com>

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 <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 |    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 da4f5d5..42a91c7 100644
--- a/tools/testing/selftests/vm/protection_keys.c
+++ b/tools/testing/selftests/vm/protection_keys.c
@@ -556,6 +556,9 @@ int alloc_pkey(void)
 int sys_pkey_free(unsigned long pkey)
 {
 	int ret = syscall(SYS_pkey_free, pkey);
+
+	if (!ret)
+		shadow_pkey_reg &= clear_pkey_flags(pkey, PKEY_DISABLE_ACCESS);
 	dprintf1("%s(pkey=%ld) syscall ret: %d\n", __func__, pkey, ret);
 	return ret;
 }
-- 
1.7.1
