[v14,15/22] selftests/vm: powerpc implementation to check support for pkey
diff mbox

Message ID 1531835365-32387-16-git-send-email-linuxram@us.ibm.com
State New
Headers show

Commit Message

Ram Pai July 17, 2018, 1:49 p.m. UTC
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(-)

Comments

Dave Hansen July 18, 2018, 4:42 p.m. UTC | #1
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;
  	}


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Patch
diff mbox

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;