From 94c8a223ded59918536387a9c33fee29ca54fc7e Mon Sep 17 00:00:00 2001 From: Ram Pai Date: Thu, 4 Jun 2020 16:52:25 -0700 Subject: [PATCH] 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. Signed-off-by: Ram Pai Signed-off-by: Sandipan Das Signed-off-by: Andrew Morton 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 Link: http://lkml.kernel.org/r/8fb76c63ebdadcf068ecd2d23731032e195cd364.1585646528.git.sandipan@linux.ibm.com Signed-off-by: Linus Torvalds --- 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(-) diff --git a/tools/testing/selftests/vm/pkey-helpers.h b/tools/testing/selftests/vm/pkey-helpers.h index 2f4b1eb..59ccdff 100644 --- a/tools/testing/selftests/vm/pkey-helpers.h +++ b/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(siginfo_t *si) #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 */ diff --git a/tools/testing/selftests/vm/pkey-powerpc.h b/tools/testing/selftests/vm/pkey-powerpc.h index 7ad283d..1f82caa 100644 --- a/tools/testing/selftests/vm/pkey-powerpc.h +++ b/tools/testing/selftests/vm/pkey-powerpc.h @@ -64,8 +64,9 @@ static inline void __write_pkey_reg(u64 pkey_reg) __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; } diff --git a/tools/testing/selftests/vm/pkey-x86.h b/tools/testing/selftests/vm/pkey-x86.h index a0c59d4..6421b84 100644 --- a/tools/testing/selftests/vm/pkey-x86.h +++ b/tools/testing/selftests/vm/pkey-x86.h @@ -97,7 +97,7 @@ 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 int cpu_has_pkeys(void) { unsigned int eax; unsigned int ebx; diff --git a/tools/testing/selftests/vm/protection_keys.c b/tools/testing/selftests/vm/protection_keys.c index 5fcbbc5..95f1730 100644 --- a/tools/testing/selftests/vm/protection_keys.c +++ b/tools/testing/selftests/vm/protection_keys.c @@ -1378,7 +1378,7 @@ void test_mprotect_pkey_on_unsupported_cpu(int *ptr, u16 pkey) 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; -- 2.7.4