// 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>

#include "vdso_config.h"

static const char **name;

#ifndef SYS_getcpu
# ifdef __x86_64__
#  define SYS_getcpu 309
# else
#  define SYS_getcpu 318
# endif
#endif

#ifndef __NR_clock_gettime64
#define __NR_clock_gettime64    403
#endif

#ifndef __kernel_timespec
struct __kernel_timespec {
        long long       tv_sec;
        long long       tv_nsec;
};
#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 int (*vgettime64_t)(clockid_t, struct __kernel_timespec *);

vgettime64_t vdso_clock_gettime64;

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, name[4]);
        if (!vdso_getcpu)
                printf("Warning: failed to find getcpu in vDSO\n");

        vgetcpu = (getcpu_t) vsyscall_getcpu();

        vdso_clock_gettime = (vgettime_t)dlsym(vdso, name[1]);
        if (!vdso_clock_gettime)
                printf("Warning: failed to find clock_gettime in vDSO\n");

#if defined(VDSO_32BIT)
        vdso_clock_gettime64 = (vgettime64_t)dlsym(vdso, name[5]);
        if (!vdso_clock_gettime64)
                printf("Warning: failed to find clock_gettime64 in vDSO\n");
#endif

        vdso_gettimeofday = (vgtod_t)dlsym(vdso, name[0]);
        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_clock_gettime64(clockid_t id, struct __kernel_timespec *ts)
{
        return syscall(__NR_clock_gettime64, 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 ts64_leq(const struct __kernel_timespec *a,
                     const struct __kernel_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++;
                return;
        }

        printf("[OK]\tTest Passed.\n");
}

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_one_clock_gettime64(int clock, const char *name)
{
        struct __kernel_timespec start, vdso, end;
        int vdso_ret, end_ret;

        printf("[RUN]\tTesting clock_gettime64 for clock %s (%d)...\n", name, clock);

        if (sys_clock_gettime64(clock, &start) < 0) {
                if (errno == EINVAL) {
                        vdso_ret = vdso_clock_gettime64(clock, &vdso);
                        if (vdso_ret == -EINVAL) {
                                printf("[OK]\tNo such clock.\n");
                        } else {
                                printf("[FAIL]\tNo such clock, but __vdso_clock_gettime64 returned %d\n", vdso_ret);
                                nerrs++;
                        }
                } else {
                        printf("[WARN]\t clock_gettime64(%d) syscall returned error %d\n", clock, errno);
                }
                return;
        }

        vdso_ret = vdso_clock_gettime64(clock, &vdso);
        end_ret = sys_clock_gettime64(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.%09lld %llu.%09lld %llu.%09lld\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 (!ts64_leq(&start, &vdso) || !ts64_leq(&vdso, &end)) {
                printf("[FAIL]\tTimes are out of sequence\n");
                nerrs++;
                return;
        }

        printf("[OK]\tTest Passed.\n");
}

static void test_clock_gettime64(void)
{
        if (!vdso_clock_gettime64) {
                printf("[SKIP]\tNo vDSO, so skipping clock_gettime64() tests\n");
                return;
        }

        for (int clock = 0; clock < sizeof(clocknames) / sizeof(clocknames[0]);
             clock++) {
                test_one_clock_gettime64(clock, clocknames[clock]);
        }

        /* Also test some invalid clock ids */
        test_one_clock_gettime64(-1, "invalid");
        test_one_clock_gettime64(INT_MIN, "invalid");
        test_one_clock_gettime64(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)
{
        name = (const char **)&names[VDSO_NAMES];

        fill_function_pointers();

        test_clock_gettime();
        test_clock_gettime64();
        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;
}