From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: [patch 117/127] selftests/vm/pkeys: improve checks to determine pkey support Date: Thu, 04 Jun 2020 16:52:25 -0700 Message-ID: <20200604235225.U0zFMJf3c%akpm@linux-foundation.org> References: <20200604164523.e15f3177f4b69dcb4f2534a1@linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Return-path: Received: from mail.kernel.org ([198.145.29.99]:51694 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725943AbgFDXw2 (ORCPT ); Thu, 4 Jun 2020 19:52:28 -0400 In-Reply-To: <20200604164523.e15f3177f4b69dcb4f2534a1@linux-foundation.org> Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: akpm@linux-foundation.org, aneesh.kumar@linux.ibm.com, bauerman@linux.ibm.com, dave.hansen@intel.com, desnesn@linux.vnet.ibm.com, fweimer@redhat.com, linux-mm@kvack.org, linuxram@us.ibm.com, mhocko@kernel.org, mingo@kernel.org, mm-commits@vger.kernel.org, mpe@ellerman.id.au, msuchanek@suse.de, sandipan@linux.ibm.com, shuah@kernel.org, torvalds@linux-foundation.org From: Ram Pai Subject: selftests/vm/pkeys: improve checks to determine pkey support For the pkeys subsystem to work, both the CPU and the kernel need to have support. So, additionally check if the kernel supports pkeys apart from the CPU feature checks. Link: http://lkml.kernel.org/r/8fb76c63ebdadcf068ecd2d23731032e195cd364.1585646528.git.sandipan@linux.ibm.com Signed-off-by: Ram Pai Signed-off-by: Sandipan Das Acked-by: Dave Hansen Cc: Dave Hansen Cc: Florian Weimer Cc: "Desnes A. Nunes do Rosario" Cc: Ingo Molnar Cc: Thiago Jung Bauermann Cc: "Aneesh Kumar K.V" Cc: Michael Ellerman Cc: Michal Hocko Cc: Michal Suchanek Cc: Shuah Khan Signed-off-by: Andrew Morton --- tools/testing/selftests/vm/pkey-helpers.h | 30 +++++++++++++++++ tools/testing/selftests/vm/pkey-powerpc.h | 3 + tools/testing/selftests/vm/pkey-x86.h | 2 - tools/testing/selftests/vm/protection_keys.c | 7 ++- 4 files changed, 37 insertions(+), 5 deletions(-) --- a/tools/testing/selftests/vm/pkey-helpers.h~selftests-vm-pkeys-improve-checks-to-determine-pkey-support +++ a/tools/testing/selftests/vm/pkey-helpers.h @@ -76,6 +76,8 @@ extern void abort_hooks(void); __attribute__((noinline)) int read_ptr(int *ptr); void expected_pkey_fault(int pkey); +int sys_pkey_alloc(unsigned long flags, unsigned long init_val); +int sys_pkey_free(unsigned long pkey); #if defined(__i386__) || defined(__x86_64__) /* arch */ #include "pkey-x86.h" @@ -186,4 +188,32 @@ static inline u32 *siginfo_get_pkey_ptr( #endif } +static inline int kernel_has_pkeys(void) +{ + /* try allocating a key and see if it succeeds */ + int ret = sys_pkey_alloc(0, 0); + if (ret <= 0) { + return 0; + } + sys_pkey_free(ret); + return 1; +} + +static inline int is_pkeys_supported(void) +{ + /* check if the cpu supports pkeys */ + if (!cpu_has_pkeys()) { + dprintf1("SKIP: %s: no CPU support\n", __func__); + return 0; + } + + /* check if the kernel supports pkeys */ + if (!kernel_has_pkeys()) { + dprintf1("SKIP: %s: no kernel support\n", __func__); + return 0; + } + + return 1; +} + #endif /* _PKEYS_HELPER_H */ --- a/tools/testing/selftests/vm/pkey-powerpc.h~selftests-vm-pkeys-improve-checks-to-determine-pkey-support +++ a/tools/testing/selftests/vm/pkey-powerpc.h @@ -64,8 +64,9 @@ static inline void __write_pkey_reg(u64 __func__, __read_pkey_reg(), pkey_reg); } -static inline int cpu_has_pku(void) +static inline int cpu_has_pkeys(void) { + /* No simple way to determine this */ return 1; } --- a/tools/testing/selftests/vm/pkey-x86.h~selftests-vm-pkeys-improve-checks-to-determine-pkey-support +++ a/tools/testing/selftests/vm/pkey-x86.h @@ -97,7 +97,7 @@ static inline void __cpuid(unsigned int #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 int cpu_has_pkeys(void) { unsigned int eax; unsigned int ebx; --- a/tools/testing/selftests/vm/protection_keys.c~selftests-vm-pkeys-improve-checks-to-determine-pkey-support +++ a/tools/testing/selftests/vm/protection_keys.c @@ -1378,7 +1378,7 @@ void test_mprotect_pkey_on_unsupported_c int size = PAGE_SIZE; int sret; - if (cpu_has_pku()) { + if (cpu_has_pkeys()) { dprintf1("SKIP: %s: no CPU support\n", __func__); return; } @@ -1447,12 +1447,13 @@ void pkey_setup_shadow(void) int main(void) { int nr_iterations = 22; + int pkeys_supported = is_pkeys_supported(); setup_handlers(); - printf("has pku: %d\n", cpu_has_pku()); + printf("has pkeys: %d\n", pkeys_supported); - if (!cpu_has_pku()) { + if (!pkeys_supported) { int size = PAGE_SIZE; int *ptr; _