pkey subsystem is supported if the hardware and kernel has support. We determine that by checking if allocation of a key succeeds or not.
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/pkey-helpers.h | 22 ++++++++++++++++------ tools/testing/selftests/vm/protection_keys.c | 9 +++++---- 2 files changed, 21 insertions(+), 10 deletions(-)
diff --git a/tools/testing/selftests/vm/pkey-helpers.h b/tools/testing/selftests/vm/pkey-helpers.h index c47aead..88ef58f 100644 --- a/tools/testing/selftests/vm/pkey-helpers.h +++ b/tools/testing/selftests/vm/pkey-helpers.h @@ -258,7 +258,7 @@ static inline void __cpuid(unsigned int *eax, unsigned int *ebx, #define X86_FEATURE_PKU (1<<3) /* Protection Keys for Userspace */ #define X86_FEATURE_OSPKE (1<<4) /* OS Protection Keys Enable */
-static inline int cpu_has_pku(void) +static inline bool is_pkey_supported(void) { unsigned int eax; unsigned int ebx; @@ -271,13 +271,13 @@ static inline int cpu_has_pku(void)
if (!(ecx & X86_FEATURE_PKU)) { dprintf2("cpu does not have PKU\n"); - return 0; + return false; } if (!(ecx & X86_FEATURE_OSPKE)) { dprintf2("cpu does not have OSPKE\n"); - return 0; + return false; } - return 1; + return true; }
#define XSTATE_PKEY_BIT (9) @@ -323,9 +323,19 @@ static inline void __page_o_noops(void) #elif __powerpc64__ /* arch */
#define PAGE_SIZE (0x1UL << 16) -static inline int cpu_has_pku(void) +static inline bool is_pkey_supported(void) { - return 1; + /* + * No simple way to determine this. + * lets try allocating a key and see if it succeeds. + */ + int ret = sys_pkey_alloc(0, 0); + + if (ret > 0) { + sys_pkey_free(ret); + return true; + } + return false; }
/* 8-bytes of instruction * 16384bytes = 1 page */ diff --git a/tools/testing/selftests/vm/protection_keys.c b/tools/testing/selftests/vm/protection_keys.c index e82bd88..58da5a0 100644 --- a/tools/testing/selftests/vm/protection_keys.c +++ b/tools/testing/selftests/vm/protection_keys.c @@ -1299,8 +1299,8 @@ void test_mprotect_pkey_on_unsupported_cpu(int *ptr, u16 pkey) int size = PAGE_SIZE; int sret;
- if (cpu_has_pku()) { - dprintf1("SKIP: %s: no CPU support\n", __func__); + if (is_pkey_supported()) { + dprintf1("SKIP: %s: no CPU/kernel support\n", __func__); return; }
@@ -1362,12 +1362,13 @@ void run_tests_once(void) int main(void) { int nr_iterations = 22; + int pkey_supported = is_pkey_supported();
setup_handlers();
- printf("has pkey: %d\n", cpu_has_pku()); + printf("has pkey: %s\n", pkey_supported ? "Yes" : "No");
- if (!cpu_has_pku()) { + if (!pkey_supported) { int size = PAGE_SIZE; int *ptr;