x86/pkeys/selftests: Allow faults on unknown keys

[ Upstream commit 7e7fd67ca39335a49619729821efb7cbdd674eb0 ]

The exec-only pkey is allocated inside the kernel and userspace
is not told what it is.  So, allow PK faults to occur that have
an unknown key.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Ellermen <mpe@ellerman.id.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ram Pai <linuxram@us.ibm.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20180509171345.7FC7DA00@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/tools/testing/selftests/x86/protection_keys.c b/tools/testing/selftests/x86/protection_keys.c
index 5f5aedb..7d95acd 100644 (file)
--- a/tools/testing/selftests/x86/protection_keys.c
+++ b/tools/testing/selftests/x86/protection_keys.c
@@ -921,13 +921,21 @@ void *malloc_pkey(long size, int prot, u16 pkey)
 }
 
 int last_pkru_faults;
+#define UNKNOWN_PKEY -2
 void expected_pk_fault(int pkey)
 {
        dprintf2("%s(): last_pkru_faults: %d pkru_faults: %d\n",
                        __func__, last_pkru_faults, pkru_faults);
        dprintf2("%s(%d): last_si_pkey: %d\n", __func__, pkey, last_si_pkey);
        pkey_assert(last_pkru_faults + 1 == pkru_faults);
-       pkey_assert(last_si_pkey == pkey);
+
+       /*
+       * For exec-only memory, we do not know the pkey in
+       * advance, so skip this check.
+       */
+       if (pkey != UNKNOWN_PKEY)
+               pkey_assert(last_si_pkey == pkey);
+
        /*
         * The signal handler shold have cleared out PKRU to let the
         * test program continue.  We now have to restore it.