| Message ID | 1531835365-32387-16-git-send-email-linuxram@us.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 07/17/2018 06:49 AM, Ram Pai wrote: > -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; > } This actually works on x86 too. > static inline int arch_reserved_keys(void) > diff --git a/tools/testing/selftests/vm/pkey-x86.h b/tools/testing/selftests/vm/pkey-x86.h > index f5d0ff2..887acf2 100644 > --- a/tools/testing/selftests/vm/pkey-x86.h > +++ b/tools/testing/selftests/vm/pkey-x86.h > @@ -105,7 +105,7 @@ 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; > @@ -118,13 +118,13 @@ 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) > diff --git a/tools/testing/selftests/vm/protection_keys.c b/tools/testing/selftests/vm/protection_keys.c > index 18e1bb7..d27fa5e 100644 > --- a/tools/testing/selftests/vm/protection_keys.c > +++ b/tools/testing/selftests/vm/protection_keys.c > @@ -1389,8 +1389,8 @@ 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; > } I actually wanted a kernel-independent check, based entirely on CPUID. That's specifically why I said "no CPU support". If you want to do this, please do: /* powerpc has no enumeration, just assume it has support: */ static inline bool cpu_has_cpu(void) { return true; }; if (cpu_has_pku()) { dprintf1("SKIP: %s: no CPU support\n", __func__); return } if (kernel_pkey_supported()) { dprintf1("SKIP: %s: no kernel support\n", __func__); return; }
diff --git a/tools/testing/selftests/vm/pkey-helpers.h b/tools/testing/selftests/vm/pkey-helpers.h index 321bbbd..288ccff 100644 --- a/tools/testing/selftests/vm/pkey-helpers.h +++ b/tools/testing/selftests/vm/pkey-helpers.h @@ -76,6 +76,8 @@ static inline void sigsafe_printf(const char *format, ...) __attribute__((noinline)) int read_ptr(int *ptr); void expected_pkey_fault(int pkey); +int sys_pkey_alloc(unsigned long flags, u64 init_val); +int sys_pkey_free(unsigned long pkey); #if defined(__i386__) || defined(__x86_64__) /* arch */ #include "pkey-x86.h" diff --git a/tools/testing/selftests/vm/pkey-powerpc.h b/tools/testing/selftests/vm/pkey-powerpc.h index b0d1abe..b649e85 100644 --- a/tools/testing/selftests/vm/pkey-powerpc.h +++ b/tools/testing/selftests/vm/pkey-powerpc.h @@ -64,9 +64,19 @@ static inline void __write_pkey_reg(pkey_reg_t pkey_reg) pkey_reg); } -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; } static inline int arch_reserved_keys(void) diff --git a/tools/testing/selftests/vm/pkey-x86.h b/tools/testing/selftests/vm/pkey-x86.h index f5d0ff2..887acf2 100644 --- a/tools/testing/selftests/vm/pkey-x86.h +++ b/tools/testing/selftests/vm/pkey-x86.h @@ -105,7 +105,7 @@ 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; @@ -118,13 +118,13 @@ 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) diff --git a/tools/testing/selftests/vm/protection_keys.c b/tools/testing/selftests/vm/protection_keys.c index 18e1bb7..d27fa5e 100644 --- a/tools/testing/selftests/vm/protection_keys.c +++ b/tools/testing/selftests/vm/protection_keys.c @@ -1389,8 +1389,8 @@ 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; } @@ -1454,12 +1454,13 @@ 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;
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 | 2 ++ tools/testing/selftests/vm/pkey-powerpc.h | 14 ++++++++++++-- tools/testing/selftests/vm/pkey-x86.h | 8 ++++---- tools/testing/selftests/vm/protection_keys.c | 9 +++++---- 4 files changed, 23 insertions(+), 10 deletions(-)