From 3200ca806942d3d8f78d0d0c822e345dfb8789e7 Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Wed, 16 Nov 2016 10:23:28 -0800 Subject: [PATCH] selftests/x86: Add test_vdso to test getcpu() I'll eventually add tests for more vDSO functions here. Signed-off-by: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Megha Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/945cd29901a62a3cc6ea7d6ee5e389ab1ec1ac0c.1479320367.git.luto@kernel.org Signed-off-by: Ingo Molnar --- tools/testing/selftests/x86/Makefile | 2 +- tools/testing/selftests/x86/test_vdso.c | 123 ++++++++++++++++++++++++ 2 files changed, 124 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/x86/test_vdso.c diff --git a/tools/testing/selftests/x86/Makefile b/tools/testing/selftests/x86/Makefile index a89f80a5b711..8c1cb423cfe6 100644 --- a/tools/testing/selftests/x86/Makefile +++ b/tools/testing/selftests/x86/Makefile @@ -6,7 +6,7 @@ include ../lib.mk TARGETS_C_BOTHBITS := single_step_syscall sysret_ss_attrs syscall_nt ptrace_syscall test_mremap_vdso \ check_initial_reg_state sigreturn ldt_gdt iopl \ - protection_keys + protection_keys test_vdso TARGETS_C_32BIT_ONLY := entry_from_vm86 syscall_arg_fault test_syscall_vdso unwind_vdso \ test_FCMOV test_FCOMI test_FISTTP \ vdso_restorer diff --git a/tools/testing/selftests/x86/test_vdso.c b/tools/testing/selftests/x86/test_vdso.c new file mode 100644 index 000000000000..65d7a2bf7e14 --- /dev/null +++ b/tools/testing/selftests/x86/test_vdso.c @@ -0,0 +1,123 @@ +/* + * ldt_gdt.c - Test cases for LDT and GDT access + * Copyright (c) 2011-2015 Andrew Lutomirski + */ + +#define _GNU_SOURCE + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#ifndef SYS_getcpu +# ifdef __x86_64__ +# define SYS_getcpu 309 +# else +# define SYS_getcpu 318 +# endif +#endif + +int nerrs = 0; + +#ifdef __x86_64__ +# define VSYS(x) (x) +#else +# define VSYS(x) 0 +#endif + +typedef long (*getcpu_t)(unsigned *, unsigned *, void *); + +const getcpu_t vgetcpu = (getcpu_t)VSYS(0xffffffffff600800); +getcpu_t vdso_getcpu; + +void fill_function_pointers() +{ + void *vdso = dlopen("linux-vdso.so.1", + RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD); + if (!vdso) + vdso = dlopen("linux-gate.so.1", + RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD); + if (!vdso) { + printf("[WARN]\tfailed to find vDSO\n"); + return; + } + + vdso_getcpu = (getcpu_t)dlsym(vdso, "__vdso_getcpu"); + if (!vdso_getcpu) + printf("Warning: failed to find getcpu in vDSO\n"); +} + +static long sys_getcpu(unsigned * cpu, unsigned * node, + void* cache) +{ + return syscall(__NR_getcpu, cpu, node, cache); +} + +static void test_getcpu(void) +{ + printf("[RUN]\tTesting getcpu...\n"); + + for (int cpu = 0; ; cpu++) { + cpu_set_t cpuset; + CPU_ZERO(&cpuset); + CPU_SET(cpu, &cpuset); + if (sched_setaffinity(0, sizeof(cpuset), &cpuset) != 0) + return; + + unsigned cpu_sys, cpu_vdso, cpu_vsys, + node_sys, node_vdso, node_vsys; + long ret_sys, ret_vdso = 1, ret_vsys = 1; + unsigned node; + + ret_sys = sys_getcpu(&cpu_sys, &node_sys, 0); + if (vdso_getcpu) + ret_vdso = vdso_getcpu(&cpu_vdso, &node_vdso, 0); + if (vgetcpu) + ret_vsys = vgetcpu(&cpu_vsys, &node_vsys, 0); + + if (!ret_sys) + node = node_sys; + else if (!ret_vdso) + node = node_vdso; + else if (!ret_vsys) + node = node_vsys; + + bool ok = true; + if (!ret_sys && (cpu_sys != cpu || node_sys != node)) + ok = false; + if (!ret_vdso && (cpu_vdso != cpu || node_vdso != node)) + ok = false; + if (!ret_vsys && (cpu_vsys != cpu || node_vsys != node)) + ok = false; + + printf("[%s]\tCPU %u:", ok ? "OK" : "FAIL", cpu); + if (!ret_sys) + printf(" syscall: cpu %u, node %u", cpu_sys, node_sys); + if (!ret_vdso) + printf(" vdso: cpu %u, node %u", cpu_vdso, node_vdso); + if (!ret_vsys) + printf(" vsyscall: cpu %u, node %u", cpu_vsys, + node_vsys); + printf("\n"); + + if (!ok) + nerrs++; + } +} + +int main(int argc, char **argv) +{ + fill_function_pointers(); + + test_getcpu(); + + return nerrs ? 1 : 0; +} -- 2.30.2