166 lines
3.4 KiB
C
166 lines
3.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* ldt_gdt.c - Test cases for LDT and GDT access
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* Copyright (c) 2011-2015 Andrew Lutomirski
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*/
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#define _GNU_SOURCE
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#include <stdio.h>
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#include <sys/time.h>
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#include <time.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <sys/syscall.h>
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#include <dlfcn.h>
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#include <string.h>
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#include <errno.h>
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#include <sched.h>
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#include <stdbool.h>
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#ifndef SYS_getcpu
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# ifdef __x86_64__
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# define SYS_getcpu 309
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# else
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# define SYS_getcpu 318
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# endif
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#endif
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/* max length of lines in /proc/self/maps - anything longer is skipped here */
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#define MAPS_LINE_LEN 128
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int nerrs = 0;
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typedef long (*getcpu_t)(unsigned *, unsigned *, void *);
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getcpu_t vgetcpu;
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getcpu_t vdso_getcpu;
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static void *vsyscall_getcpu(void)
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{
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#ifdef __x86_64__
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FILE *maps;
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char line[MAPS_LINE_LEN];
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bool found = false;
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maps = fopen("/proc/self/maps", "r");
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if (!maps) /* might still be present, but ignore it here, as we test vDSO not vsyscall */
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return NULL;
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while (fgets(line, MAPS_LINE_LEN, maps)) {
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char r, x;
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void *start, *end;
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char name[MAPS_LINE_LEN];
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/* sscanf() is safe here as strlen(name) >= strlen(line) */
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if (sscanf(line, "%p-%p %c-%cp %*x %*x:%*x %*u %s",
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&start, &end, &r, &x, name) != 5)
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continue;
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if (strcmp(name, "[vsyscall]"))
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continue;
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/* assume entries are OK, as we test vDSO here not vsyscall */
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found = true;
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break;
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}
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fclose(maps);
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if (!found) {
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printf("Warning: failed to find vsyscall getcpu\n");
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return NULL;
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}
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return (void *) (0xffffffffff600800);
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#else
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return NULL;
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#endif
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}
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static void fill_function_pointers()
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{
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void *vdso = dlopen("linux-vdso.so.1",
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RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD);
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if (!vdso)
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vdso = dlopen("linux-gate.so.1",
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RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD);
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if (!vdso) {
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printf("[WARN]\tfailed to find vDSO\n");
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return;
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}
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vdso_getcpu = (getcpu_t)dlsym(vdso, "__vdso_getcpu");
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if (!vdso_getcpu)
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printf("Warning: failed to find getcpu in vDSO\n");
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vgetcpu = (getcpu_t) vsyscall_getcpu();
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}
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static long sys_getcpu(unsigned * cpu, unsigned * node,
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void* cache)
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{
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return syscall(__NR_getcpu, cpu, node, cache);
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}
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static void test_getcpu(void)
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{
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printf("[RUN]\tTesting getcpu...\n");
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for (int cpu = 0; ; cpu++) {
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cpu_set_t cpuset;
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CPU_ZERO(&cpuset);
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CPU_SET(cpu, &cpuset);
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if (sched_setaffinity(0, sizeof(cpuset), &cpuset) != 0)
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return;
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unsigned cpu_sys, cpu_vdso, cpu_vsys,
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node_sys, node_vdso, node_vsys;
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long ret_sys, ret_vdso = 1, ret_vsys = 1;
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unsigned node;
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ret_sys = sys_getcpu(&cpu_sys, &node_sys, 0);
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if (vdso_getcpu)
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ret_vdso = vdso_getcpu(&cpu_vdso, &node_vdso, 0);
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if (vgetcpu)
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ret_vsys = vgetcpu(&cpu_vsys, &node_vsys, 0);
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if (!ret_sys)
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node = node_sys;
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else if (!ret_vdso)
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node = node_vdso;
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else if (!ret_vsys)
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node = node_vsys;
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bool ok = true;
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if (!ret_sys && (cpu_sys != cpu || node_sys != node))
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ok = false;
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if (!ret_vdso && (cpu_vdso != cpu || node_vdso != node))
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ok = false;
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if (!ret_vsys && (cpu_vsys != cpu || node_vsys != node))
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ok = false;
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printf("[%s]\tCPU %u:", ok ? "OK" : "FAIL", cpu);
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if (!ret_sys)
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printf(" syscall: cpu %u, node %u", cpu_sys, node_sys);
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if (!ret_vdso)
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printf(" vdso: cpu %u, node %u", cpu_vdso, node_vdso);
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if (!ret_vsys)
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printf(" vsyscall: cpu %u, node %u", cpu_vsys,
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node_vsys);
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printf("\n");
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if (!ok)
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nerrs++;
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}
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}
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int main(int argc, char **argv)
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{
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fill_function_pointers();
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test_getcpu();
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return nerrs ? 1 : 0;
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}
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