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-rw-r--r--tools/testing/selftests/x86/test_vdso.c342
1 files changed, 342 insertions, 0 deletions
diff --git a/tools/testing/selftests/x86/test_vdso.c b/tools/testing/selftests/x86/test_vdso.c
new file mode 100644
index 000000000..42052db0f
--- /dev/null
+++ b/tools/testing/selftests/x86/test_vdso.c
@@ -0,0 +1,342 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ldt_gdt.c - Test cases for LDT and GDT access
+ * Copyright (c) 2011-2015 Andrew Lutomirski
+ */
+
+#define _GNU_SOURCE
+
+#include <stdio.h>
+#include <sys/time.h>
+#include <time.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/syscall.h>
+#include <dlfcn.h>
+#include <string.h>
+#include <errno.h>
+#include <sched.h>
+#include <stdbool.h>
+#include <limits.h>
+
+#ifndef SYS_getcpu
+# ifdef __x86_64__
+# define SYS_getcpu 309
+# else
+# define SYS_getcpu 318
+# endif
+#endif
+
+/* max length of lines in /proc/self/maps - anything longer is skipped here */
+#define MAPS_LINE_LEN 128
+
+int nerrs = 0;
+
+typedef int (*vgettime_t)(clockid_t, struct timespec *);
+
+vgettime_t vdso_clock_gettime;
+
+typedef long (*vgtod_t)(struct timeval *tv, struct timezone *tz);
+
+vgtod_t vdso_gettimeofday;
+
+typedef long (*getcpu_t)(unsigned *, unsigned *, void *);
+
+getcpu_t vgetcpu;
+getcpu_t vdso_getcpu;
+
+static void *vsyscall_getcpu(void)
+{
+#ifdef __x86_64__
+ FILE *maps;
+ char line[MAPS_LINE_LEN];
+ bool found = false;
+
+ maps = fopen("/proc/self/maps", "r");
+ if (!maps) /* might still be present, but ignore it here, as we test vDSO not vsyscall */
+ return NULL;
+
+ while (fgets(line, MAPS_LINE_LEN, maps)) {
+ char r, x;
+ void *start, *end;
+ char name[MAPS_LINE_LEN];
+
+ /* sscanf() is safe here as strlen(name) >= strlen(line) */
+ if (sscanf(line, "%p-%p %c-%cp %*x %*x:%*x %*u %s",
+ &start, &end, &r, &x, name) != 5)
+ continue;
+
+ if (strcmp(name, "[vsyscall]"))
+ continue;
+
+ /* assume entries are OK, as we test vDSO here not vsyscall */
+ found = true;
+ break;
+ }
+
+ fclose(maps);
+
+ if (!found) {
+ printf("Warning: failed to find vsyscall getcpu\n");
+ return NULL;
+ }
+ return (void *) (0xffffffffff600800);
+#else
+ return NULL;
+#endif
+}
+
+
+static 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");
+
+ vgetcpu = (getcpu_t) vsyscall_getcpu();
+
+ vdso_clock_gettime = (vgettime_t)dlsym(vdso, "__vdso_clock_gettime");
+ if (!vdso_clock_gettime)
+ printf("Warning: failed to find clock_gettime in vDSO\n");
+
+ vdso_gettimeofday = (vgtod_t)dlsym(vdso, "__vdso_gettimeofday");
+ if (!vdso_gettimeofday)
+ printf("Warning: failed to find gettimeofday in vDSO\n");
+
+}
+
+static long sys_getcpu(unsigned * cpu, unsigned * node,
+ void* cache)
+{
+ return syscall(__NR_getcpu, cpu, node, cache);
+}
+
+static inline int sys_clock_gettime(clockid_t id, struct timespec *ts)
+{
+ return syscall(__NR_clock_gettime, id, ts);
+}
+
+static inline int sys_gettimeofday(struct timeval *tv, struct timezone *tz)
+{
+ return syscall(__NR_gettimeofday, tv, tz);
+}
+
+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++;
+ }
+}
+
+static bool ts_leq(const struct timespec *a, const struct timespec *b)
+{
+ if (a->tv_sec != b->tv_sec)
+ return a->tv_sec < b->tv_sec;
+ else
+ return a->tv_nsec <= b->tv_nsec;
+}
+
+static bool tv_leq(const struct timeval *a, const struct timeval *b)
+{
+ if (a->tv_sec != b->tv_sec)
+ return a->tv_sec < b->tv_sec;
+ else
+ return a->tv_usec <= b->tv_usec;
+}
+
+static char const * const clocknames[] = {
+ [0] = "CLOCK_REALTIME",
+ [1] = "CLOCK_MONOTONIC",
+ [2] = "CLOCK_PROCESS_CPUTIME_ID",
+ [3] = "CLOCK_THREAD_CPUTIME_ID",
+ [4] = "CLOCK_MONOTONIC_RAW",
+ [5] = "CLOCK_REALTIME_COARSE",
+ [6] = "CLOCK_MONOTONIC_COARSE",
+ [7] = "CLOCK_BOOTTIME",
+ [8] = "CLOCK_REALTIME_ALARM",
+ [9] = "CLOCK_BOOTTIME_ALARM",
+ [10] = "CLOCK_SGI_CYCLE",
+ [11] = "CLOCK_TAI",
+};
+
+static void test_one_clock_gettime(int clock, const char *name)
+{
+ struct timespec start, vdso, end;
+ int vdso_ret, end_ret;
+
+ printf("[RUN]\tTesting clock_gettime for clock %s (%d)...\n", name, clock);
+
+ if (sys_clock_gettime(clock, &start) < 0) {
+ if (errno == EINVAL) {
+ vdso_ret = vdso_clock_gettime(clock, &vdso);
+ if (vdso_ret == -EINVAL) {
+ printf("[OK]\tNo such clock.\n");
+ } else {
+ printf("[FAIL]\tNo such clock, but __vdso_clock_gettime returned %d\n", vdso_ret);
+ nerrs++;
+ }
+ } else {
+ printf("[WARN]\t clock_gettime(%d) syscall returned error %d\n", clock, errno);
+ }
+ return;
+ }
+
+ vdso_ret = vdso_clock_gettime(clock, &vdso);
+ end_ret = sys_clock_gettime(clock, &end);
+
+ if (vdso_ret != 0 || end_ret != 0) {
+ printf("[FAIL]\tvDSO returned %d, syscall errno=%d\n",
+ vdso_ret, errno);
+ nerrs++;
+ return;
+ }
+
+ printf("\t%llu.%09ld %llu.%09ld %llu.%09ld\n",
+ (unsigned long long)start.tv_sec, start.tv_nsec,
+ (unsigned long long)vdso.tv_sec, vdso.tv_nsec,
+ (unsigned long long)end.tv_sec, end.tv_nsec);
+
+ if (!ts_leq(&start, &vdso) || !ts_leq(&vdso, &end)) {
+ printf("[FAIL]\tTimes are out of sequence\n");
+ nerrs++;
+ }
+}
+
+static void test_clock_gettime(void)
+{
+ if (!vdso_clock_gettime) {
+ printf("[SKIP]\tNo vDSO, so skipping clock_gettime() tests\n");
+ return;
+ }
+
+ for (int clock = 0; clock < sizeof(clocknames) / sizeof(clocknames[0]);
+ clock++) {
+ test_one_clock_gettime(clock, clocknames[clock]);
+ }
+
+ /* Also test some invalid clock ids */
+ test_one_clock_gettime(-1, "invalid");
+ test_one_clock_gettime(INT_MIN, "invalid");
+ test_one_clock_gettime(INT_MAX, "invalid");
+}
+
+static void test_gettimeofday(void)
+{
+ struct timeval start, vdso, end;
+ struct timezone sys_tz, vdso_tz;
+ int vdso_ret, end_ret;
+
+ if (!vdso_gettimeofday)
+ return;
+
+ printf("[RUN]\tTesting gettimeofday...\n");
+
+ if (sys_gettimeofday(&start, &sys_tz) < 0) {
+ printf("[FAIL]\tsys_gettimeofday failed (%d)\n", errno);
+ nerrs++;
+ return;
+ }
+
+ vdso_ret = vdso_gettimeofday(&vdso, &vdso_tz);
+ end_ret = sys_gettimeofday(&end, NULL);
+
+ if (vdso_ret != 0 || end_ret != 0) {
+ printf("[FAIL]\tvDSO returned %d, syscall errno=%d\n",
+ vdso_ret, errno);
+ nerrs++;
+ return;
+ }
+
+ printf("\t%llu.%06ld %llu.%06ld %llu.%06ld\n",
+ (unsigned long long)start.tv_sec, start.tv_usec,
+ (unsigned long long)vdso.tv_sec, vdso.tv_usec,
+ (unsigned long long)end.tv_sec, end.tv_usec);
+
+ if (!tv_leq(&start, &vdso) || !tv_leq(&vdso, &end)) {
+ printf("[FAIL]\tTimes are out of sequence\n");
+ nerrs++;
+ }
+
+ if (sys_tz.tz_minuteswest == vdso_tz.tz_minuteswest &&
+ sys_tz.tz_dsttime == vdso_tz.tz_dsttime) {
+ printf("[OK]\ttimezones match: minuteswest=%d, dsttime=%d\n",
+ sys_tz.tz_minuteswest, sys_tz.tz_dsttime);
+ } else {
+ printf("[FAIL]\ttimezones do not match\n");
+ nerrs++;
+ }
+
+ /* And make sure that passing NULL for tz doesn't crash. */
+ vdso_gettimeofday(&vdso, NULL);
+}
+
+int main(int argc, char **argv)
+{
+ fill_function_pointers();
+
+ test_clock_gettime();
+ test_gettimeofday();
+
+ /*
+ * Test getcpu() last so that, if something goes wrong setting affinity,
+ * we still run the other tests.
+ */
+ test_getcpu();
+
+ return nerrs ? 1 : 0;
+}