diff mbox series

[v10,16/24] selftests/vm: fix an assertion in test_pkey_alloc_exhaust()

Message ID 1516647137-11174-17-git-send-email-linuxram@us.ibm.com (mailing list archive)
State Superseded
Headers show
Series selftests, powerpc, x86 : Memory Protection Keys | expand

Commit Message

Ram Pai Jan. 22, 2018, 6:52 p.m. UTC 
The maximum number of keys that can be allocated has to
take into consideration, that some keys are reserved by
the architecture for   specific   purpose. Hence cannot
be allocated.

Fix the assertion in test_pkey_alloc_exhaust()

Signed-off-by: Ram Pai <linuxram@us.ibm.com>
---
 tools/testing/selftests/vm/pkey-helpers.h    |   14 ++++++++++++++
 tools/testing/selftests/vm/protection_keys.c |    9 ++++-----
 2 files changed, 18 insertions(+), 5 deletions(-)
diff mbox series

Patch

diff --git a/tools/testing/selftests/vm/pkey-helpers.h b/tools/testing/selftests/vm/pkey-helpers.h
index 3559527..9d06b4a 100644
--- a/tools/testing/selftests/vm/pkey-helpers.h
+++ b/tools/testing/selftests/vm/pkey-helpers.h
@@ -401,4 +401,18 @@  static inline int get_start_key(void)
 #endif /* arch */
 }
 
+static inline int arch_reserved_keys(void)
+{
+#if defined(__i386__) || defined(__x86_64__) /* arch */
+	return NR_RESERVED_PKEYS;
+#elif __powerpc64__ /* arch */
+	if (sysconf(_SC_PAGESIZE) == 4096)
+		return NR_RESERVED_PKEYS_4K;
+	else
+		return NR_RESERVED_PKEYS_64K;
+#else /* arch */
+	NOT SUPPORTED
+#endif /* arch */
+}
+
 #endif /* _PKEYS_HELPER_H */
diff --git a/tools/testing/selftests/vm/protection_keys.c b/tools/testing/selftests/vm/protection_keys.c
index 65e6dd6..33d5839 100644
--- a/tools/testing/selftests/vm/protection_keys.c
+++ b/tools/testing/selftests/vm/protection_keys.c
@@ -1167,12 +1167,11 @@  void test_pkey_alloc_exhaust(int *ptr, u16 pkey)
 	pkey_assert(i < NR_PKEYS*2);
 
 	/*
-	 * There are 16 pkeys supported in hardware.  One is taken
-	 * up for the default (0) and another can be taken up by
-	 * an execute-only mapping.  Ensure that we can allocate
-	 * at least 14 (16-2).
+	 * There are NR_PKEYS pkeys supported in hardware. arch_reserved_keys()
+	 * are reserved. One   can   be   taken   up by an execute-only mapping.
+	 * Ensure that we can allocate at least the remaining.
 	 */
-	pkey_assert(i >= NR_PKEYS-2);
+	pkey_assert(i >= (NR_PKEYS-arch_reserved_keys()-1));
 
 	for (i = 0; i < nr_allocated_pkeys; i++) {
 		err = sys_pkey_free(allocated_pkeys[i]);