linux/tools/testing/selftests/nolibc/nolibc-test.c

/* SPDX-License-Identifier: GPL-2.0 */

#define _GNU_SOURCE
#define _LARGEFILE64_SOURCE

/* libc-specific include files
 * The program may be built in 3 ways:
 *   $(CC) -nostdlib -include /path/to/nolibc.h => NOLIBC already defined
 *   $(CC) -nostdlib -I/path/to/nolibc/sysroot  => _NOLIBC_* guards are present
 *   $(CC) with default libc                    => NOLIBC* never defined
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/auxv.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/mount.h>
#include <sys/prctl.h>
#include <sys/random.h>
#include <sys/reboot.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/sysmacros.h>
#include <sys/time.h>
#include <sys/timerfd.h>
#include <sys/utsname.h>
#include <sys/wait.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <poll.h>
#include <sched.h>
#include <signal.h>
#include <stdarg.h>
#include <stddef.h>
#include <stdint.h>
#include <time.h>
#include <unistd.h>
#include <limits.h>
#include <ctype.h>

#pragma GCC diagnostic ignored "-Wmissing-prototypes"

#include "nolibc-test-linkage.h"

/* for the type of int_fast16_t and int_fast32_t, musl differs from glibc and nolibc */
#define SINT_MAX_OF_TYPE(type) (((type)1 << (sizeof(type) * 8 - 2)) - (type)1 + ((type)1 << (sizeof(type) * 8 - 2)))
#define SINT_MIN_OF_TYPE(type) (-SINT_MAX_OF_TYPE(type) - 1)

/* will be used to test initialization of environ */
static char **test_envp;

/* will be used to test initialization of argv */
static char **test_argv;

/* will be used to test initialization of argc */
static int test_argc;

/* will be used by some test cases as readable file, please don't write it */
static const char *argv0;

/* will be used by constructor tests */
static int constructor_test_value;

static const int is_nolibc =
#ifdef NOLIBC
	1
#else
	0
#endif
;

/* definition of a series of tests */
struct test {
	const char *name;              /* test name */
	int (*func)(int min, int max); /* handler */
};

#ifndef _NOLIBC_STDLIB_H
char *itoa(int i)
{
	static char buf[12];
	int ret;

	ret = snprintf(buf, sizeof(buf), "%d", i);
	return (ret >= 0 && ret < sizeof(buf)) ? buf : "#err";
}
#endif

#define CASE_ERR(err) \
	case err: return #err

/* returns the error name (e.g. "ENOENT") for common errors, "SUCCESS" for 0,
 * or the decimal value for less common ones.
 */
static const char *errorname(int err)
{
	switch (err) {
	case 0: return "SUCCESS";
	CASE_ERR(EPERM);
	CASE_ERR(ENOENT);
	CASE_ERR(ESRCH);
	CASE_ERR(EINTR);
	CASE_ERR(EIO);
	CASE_ERR(ENXIO);
	CASE_ERR(E2BIG);
	CASE_ERR(ENOEXEC);
	CASE_ERR(EBADF);
	CASE_ERR(ECHILD);
	CASE_ERR(EAGAIN);
	CASE_ERR(ENOMEM);
	CASE_ERR(EACCES);
	CASE_ERR(EFAULT);
	CASE_ERR(ENOTBLK);
	CASE_ERR(EBUSY);
	CASE_ERR(EEXIST);
	CASE_ERR(EXDEV);
	CASE_ERR(ENODEV);
	CASE_ERR(ENOTDIR);
	CASE_ERR(EISDIR);
	CASE_ERR(EINVAL);
	CASE_ERR(ENFILE);
	CASE_ERR(EMFILE);
	CASE_ERR(ENOTTY);
	CASE_ERR(ETXTBSY);
	CASE_ERR(EFBIG);
	CASE_ERR(ENOSPC);
	CASE_ERR(ESPIPE);
	CASE_ERR(EROFS);
	CASE_ERR(EMLINK);
	CASE_ERR(EPIPE);
	CASE_ERR(EDOM);
	CASE_ERR(ERANGE);
	CASE_ERR(ENOSYS);
	CASE_ERR(EOVERFLOW);
	default:
		return itoa(err);
	}
}

static void align_result(size_t llen)
{
	const size_t align = 64;
	char buf[align];
	size_t n;

	if (llen >= align)
		return;

	n = align - llen;
	memset(buf, ' ', n);
	buf[n] = '\0';
	fputs(buf, stdout);
}

enum RESULT {
	OK,
	FAIL,
	SKIPPED,
};

static void result(int llen, enum RESULT r)
{
	const char *msg;

	if (r == OK)
		msg = "  [OK]";
	else if (r == SKIPPED)
		msg = "[SKIPPED]";
	else
		msg = " [FAIL]";

	align_result(llen);
	puts(msg);
}

/* The tests below are intended to be used by the macroes, which evaluate
 * expression <expr>, print the status to stdout, and update the "ret"
 * variable to count failures. The functions themselves return the number
 * of failures, thus either 0 or 1.
 */

#define EXPECT_ZR(cond, expr)				\
	do { if (!(cond)) result(llen, SKIPPED); else ret += expect_zr(expr, llen); } while (0)

static __attribute__((unused))
int expect_zr(int expr, int llen)
{
	int ret = !(expr == 0);

	llen += printf(" = %d ", expr);
	result(llen, ret ? FAIL : OK);
	return ret;
}


#define EXPECT_NZ(cond, expr, val)			\
	do { if (!(cond)) result(llen, SKIPPED); else ret += expect_nz(expr, llen; } while (0)

static __attribute__((unused))
int expect_nz(int expr, int llen)
{
	int ret = !(expr != 0);

	llen += printf(" = %d ", expr);
	result(llen, ret ? FAIL : OK);
	return ret;
}


#define EXPECT_EQ(cond, expr, val)				\
	do { if (!(cond)) result(llen, SKIPPED); else ret += expect_eq(expr, llen, val); } while (0)

static __attribute__((unused))
int expect_eq(uint64_t expr, int llen, uint64_t val)
{
	int ret = !(expr == val);

	llen += printf(" = %lld ", (long long)expr);
	result(llen, ret ? FAIL : OK);
	return ret;
}


#define EXPECT_NE(cond, expr, val)				\
	do { if (!(cond)) result(llen, SKIPPED); else ret += expect_ne(expr, llen, val); } while (0)

static __attribute__((unused))
int expect_ne(int expr, int llen, int val)
{
	int ret = !(expr != val);

	llen += printf(" = %d ", expr);
	result(llen, ret ? FAIL : OK);
	return ret;
}


#define EXPECT_GE(cond, expr, val)				\
	do { if (!(cond)) result(llen, SKIPPED); else ret += expect_ge(expr, llen, val); } while (0)

static __attribute__((unused))
int expect_ge(int expr, int llen, int val)
{
	int ret = !(expr >= val);

	llen += printf(" = %d ", expr);
	result(llen, ret ? FAIL : OK);
	return ret;
}


#define EXPECT_GT(cond, expr, val)				\
	do { if (!(cond)) result(llen, SKIPPED); else ret += expect_gt(expr, llen, val); } while (0)

static __attribute__((unused))
int expect_gt(int expr, int llen, int val)
{
	int ret = !(expr > val);

	llen += printf(" = %d ", expr);
	result(llen, ret ? FAIL : OK);
	return ret;
}


#define EXPECT_LE(cond, expr, val)				\
	do { if (!(cond)) result(llen, SKIPPED); else ret += expect_le(expr, llen, val); } while (0)

static __attribute__((unused))
int expect_le(int expr, int llen, int val)
{
	int ret = !(expr <= val);

	llen += printf(" = %d ", expr);
	result(llen, ret ? FAIL : OK);
	return ret;
}


#define EXPECT_LT(cond, expr, val)				\
	do { if (!(cond)) result(llen, SKIPPED); else ret += expect_lt(expr, llen, val); } while (0)

static __attribute__((unused))
int expect_lt(int expr, int llen, int val)
{
	int ret = !(expr < val);

	llen += printf(" = %d ", expr);
	result(llen, ret ? FAIL : OK);
	return ret;
}


#define EXPECT_SYSZR(cond, expr)				\
	do { if (!(cond)) result(llen, SKIPPED); else ret += expect_syszr(expr, llen); } while (0)

static __attribute__((unused))
int expect_syszr(int expr, int llen)
{
	int ret = 0;

	if (errno == ENOSYS) {
		llen += printf(" = ENOSYS");
		result(llen, SKIPPED);
	} else if (expr) {
		ret = 1;
		llen += printf(" = %d %s ", expr, errorname(errno));
		result(llen, FAIL);
	} else {
		llen += printf(" = %d ", expr);
		result(llen, OK);
	}
	return ret;
}


#define EXPECT_SYSEQ(cond, expr, val)				\
	do { if (!(cond)) result(llen, SKIPPED); else ret += expect_syseq(expr, llen, val); } while (0)

static __attribute__((unused))
int expect_syseq(int expr, int llen, int val)
{
	int ret = 0;

	if (expr != val) {
		ret = 1;
		llen += printf(" = %d %s ", expr, errorname(errno));
		result(llen, FAIL);
	} else {
		llen += printf(" = %d ", expr);
		result(llen, OK);
	}
	return ret;
}


#define EXPECT_SYSNE(cond, expr, val)				\
	do { if (!(cond)) result(llen, SKIPPED); else ret += expect_sysne(expr, llen, val); } while (0)

static __attribute__((unused))
int expect_sysne(int expr, int llen, int val)
{
	int ret = 0;

	if (errno == ENOSYS) {
		llen += printf(" = ENOSYS");
		result(llen, SKIPPED);
	} else if (expr == val) {
		ret = 1;
		llen += printf(" = %d %s ", expr, errorname(errno));
		result(llen, FAIL);
	} else {
		llen += printf(" = %d ", expr);
		result(llen, OK);
	}
	return ret;
}


#define EXPECT_SYSER2(cond, expr, expret, experr1, experr2)		\
	do { if (!(cond)) result(llen, SKIPPED); else ret += expect_syserr2(expr, expret, experr1, experr2, llen); } while (0)

#define EXPECT_SYSER(cond, expr, expret, experr)			\
	EXPECT_SYSER2(cond, expr, expret, experr, 0)

static __attribute__((unused))
int expect_syserr2(int expr, int expret, int experr1, int experr2, int llen)
{
	int ret = 0;
	int _errno = errno;

	llen += printf(" = %d %s ", expr, errorname(_errno));
	if (errno == ENOSYS) {
		result(llen, SKIPPED);
	} else if (expr != expret || (_errno != experr1 && _errno != experr2)) {
		ret = 1;
		if (experr2 == 0)
			llen += printf(" != (%d %s) ", expret, errorname(experr1));
		else
			llen += printf(" != (%d %s %s) ", expret, errorname(experr1), errorname(experr2));
		result(llen, FAIL);
	} else {
		result(llen, OK);
	}
	return ret;
}


#define EXPECT_PTRZR(cond, expr)				\
	do { if (!(cond)) result(llen, SKIPPED); else ret += expect_ptrzr(expr, llen); } while (0)

static __attribute__((unused))
int expect_ptrzr(const void *expr, int llen)
{
	int ret = 0;

	llen += printf(" = <%p> ", expr);
	if (expr) {
		ret = 1;
		result(llen, FAIL);
	} else {
		result(llen, OK);
	}
	return ret;
}


#define EXPECT_PTRNZ(cond, expr)				\
	do { if (!(cond)) result(llen, SKIPPED); else ret += expect_ptrnz(expr, llen); } while (0)

static __attribute__((unused))
int expect_ptrnz(const void *expr, int llen)
{
	int ret = 0;

	llen += printf(" = <%p> ", expr);
	if (!expr) {
		ret = 1;
		result(llen, FAIL);
	} else {
		result(llen, OK);
	}
	return ret;
}

#define EXPECT_PTREQ(cond, expr, cmp)				\
	do { if (!(cond)) result(llen, SKIPPED); else ret += expect_ptreq(expr, llen, cmp); } while (0)

static __attribute__((unused))
int expect_ptreq(const void *expr, int llen, const void *cmp)
{
	int ret = 0;

	llen += printf(" = <%p> ", expr);
	if (expr != cmp) {
		ret = 1;
		result(llen, FAIL);
	} else {
		result(llen, OK);
	}
	return ret;
}

#define EXPECT_PTRNE(cond, expr, cmp)				\
	do { if (!(cond)) result(llen, SKIPPED); else ret += expect_ptrne(expr, llen, cmp); } while (0)

static __attribute__((unused))
int expect_ptrne(const void *expr, int llen, const void *cmp)
{
	int ret = 0;

	llen += printf(" = <%p> ", expr);
	if (expr == cmp) {
		ret = 1;
		result(llen, FAIL);
	} else {
		result(llen, OK);
	}
	return ret;
}

#define EXPECT_PTRGE(cond, expr, cmp)				\
	do { if (!(cond)) result(llen, SKIPPED); else ret += expect_ptrge(expr, llen, cmp); } while (0)

static __attribute__((unused))
int expect_ptrge(const void *expr, int llen, const void *cmp)
{
	int ret = !(expr >= cmp);

	llen += printf(" = <%p> ", expr);
	result(llen, ret ? FAIL : OK);
	return ret;
}

#define EXPECT_PTRGT(cond, expr, cmp)				\
	do { if (!(cond)) result(llen, SKIPPED); else ret += expect_ptrgt(expr, llen, cmp); } while (0)

static __attribute__((unused))
int expect_ptrgt(const void *expr, int llen, const void *cmp)
{
	int ret = !(expr > cmp);

	llen += printf(" = <%p> ", expr);
	result(llen, ret ? FAIL : OK);
	return ret;
}


#define EXPECT_PTRLE(cond, expr, cmp)				\
	do { if (!(cond)) result(llen, SKIPPED); else ret += expect_ptrle(expr, llen, cmp); } while (0)

static __attribute__((unused))
int expect_ptrle(const void *expr, int llen, const void *cmp)
{
	int ret = !(expr <= cmp);

	llen += printf(" = <%p> ", expr);
	result(llen, ret ? FAIL : OK);
	return ret;
}


#define EXPECT_PTRLT(cond, expr, cmp)				\
	do { if (!(cond)) result(llen, SKIPPED); else ret += expect_ptrlt(expr, llen, cmp); } while (0)

static __attribute__((unused))
int expect_ptrlt(const void *expr, int llen, const void *cmp)
{
	int ret = !(expr < cmp);

	llen += printf(" = <%p> ", expr);
	result(llen, ret ? FAIL : OK);
	return ret;
}

#define EXPECT_PTRER2(cond, expr, expret, experr1, experr2)		\
	do { if (!(cond)) result(llen, SKIPPED); else ret += expect_ptrerr2(expr, expret, experr1, experr2, llen); } while (0)

#define EXPECT_PTRER(cond, expr, expret, experr)			\
	EXPECT_PTRER2(cond, expr, expret, experr, 0)

static __attribute__((unused))
int expect_ptrerr2(const void *expr, const void *expret, int experr1, int experr2, int llen)
{
	int ret = 0;
	int _errno = errno;

	llen += printf(" = <%p> %s ", expr, errorname(_errno));
	if (expr != expret || (_errno != experr1 && _errno != experr2)) {
		ret = 1;
		if (experr2 == 0)
			llen += printf(" != (<%p> %s) ", expret, errorname(experr1));
		else
			llen += printf(" != (<%p> %s %s) ", expret, errorname(experr1), errorname(experr2));
		result(llen, FAIL);
	} else {
		result(llen, OK);
	}
	return ret;
}

#define EXPECT_STRZR(cond, expr)				\
	do { if (!(cond)) result(llen, SKIPPED); else ret += expect_strzr(expr, llen); } while (0)

static __attribute__((unused))
int expect_strzr(const char *expr, int llen)
{
	int ret = 0;

	llen += printf(" = <%s> ", expr ? expr : "(null)");
	if (expr) {
		ret = 1;
		result(llen, FAIL);
	} else {
		result(llen, OK);
	}
	return ret;
}


#define EXPECT_STRNZ(cond, expr)				\
	do { if (!(cond)) result(llen, SKIPPED); else ret += expect_strnz(expr, llen); } while (0)

static __attribute__((unused))
int expect_strnz(const char *expr, int llen)
{
	int ret = 0;

	llen += printf(" = <%s> ", expr ? expr : "(null)");
	if (!expr) {
		ret = 1;
		result(llen, FAIL);
	} else {
		result(llen, OK);
	}
	return ret;
}


#define EXPECT_STREQ(cond, expr, cmp)				\
	do { if (!(cond)) result(llen, SKIPPED); else ret += expect_streq(expr, llen, cmp); } while (0)

static __attribute__((unused))
int expect_streq(const char *expr, int llen, const char *cmp)
{
	int ret = 0;

	llen += printf(" = <%s> ", expr);
	if (strcmp(expr, cmp) != 0) {
		ret = 1;
		result(llen, FAIL);
	} else {
		result(llen, OK);
	}
	return ret;
}


#define EXPECT_STRNE(cond, expr, cmp)				\
	do { if (!(cond)) result(llen, SKIPPED); else ret += expect_strne(expr, llen, cmp); } while (0)

static __attribute__((unused))
int expect_strne(const char *expr, int llen, const char *cmp)
{
	int ret = 0;

	llen += printf(" = <%s> ", expr);
	if (strcmp(expr, cmp) == 0) {
		ret = 1;
		result(llen, FAIL);
	} else {
		result(llen, OK);
	}
	return ret;
}

#define EXPECT_STRBUFEQ(cond, expr, buf, val, cmp)				\
	do { if (!(cond)) result(llen, SKIPPED); else ret += expect_str_buf_eq(expr, buf, val, llen, cmp); } while (0)

static __attribute__((unused))
int expect_str_buf_eq(size_t expr, const char *buf, size_t val, int llen, const char *cmp)
{
	llen += printf(" = %lu <%s> ", (unsigned long)expr, buf);
	if (strcmp(buf, cmp) != 0) {
		result(llen, FAIL);
		return 1;
	}
	if (expr != val) {
		result(llen, FAIL);
		return 1;
	}

	result(llen, OK);
	return 0;
}

#define EXPECT_STRTOX(cond, func, input, base, expected, chars, expected_errno)				\
	do { if (!(cond)) result(llen, SKIPPED); else ret += expect_strtox(llen, func, input, base, expected, chars, expected_errno); } while (0)

static __attribute__((unused))
int expect_strtox(int llen, void *func, const char *input, int base, intmax_t expected, int expected_chars, int expected_errno)
{
	char *endptr;
	int actual_errno, actual_chars;
	intmax_t r;

	errno = 0;
	if (func == strtol) {
		r = strtol(input, &endptr, base);
	} else if (func == strtoul) {
		r = strtoul(input, &endptr, base);
	} else {
		result(llen, FAIL);
		return 1;
	}
	actual_errno = errno;
	actual_chars = endptr - input;

	llen += printf(" %lld = %lld", (long long)expected, (long long)r);
	if (r != expected) {
		result(llen, FAIL);
		return 1;
	}
	if (expected_chars == -1) {
		if (*endptr != '\0') {
			result(llen, FAIL);
			return 1;
		}
	} else if (expected_chars != actual_chars) {
		result(llen, FAIL);
		return 1;
	}
	if (actual_errno != expected_errno) {
		result(llen, FAIL);
		return 1;
	}

	result(llen, OK);
	return 0;
}

/* declare tests based on line numbers. There must be exactly one test per line. */
#define CASE_TEST(name) \
	case __LINE__: llen += printf("%d %s", test, #name);

/* constructors validate that they are executed in definition order */
__attribute__((constructor))
static void constructor1(void)
{
	constructor_test_value |= 1 << 0;
}

__attribute__((constructor))
static void constructor2(int argc, char **argv, char **envp)
{
	if (argc && argv && envp)
		constructor_test_value |= 1 << 1;
}

int run_startup(int min, int max)
{
	int test;
	int ret = 0;
	/* kernel at least passes HOME and TERM, shell passes more */
	int env_total = 2;
	/* checking NULL for argv/argv0, environ and _auxv is not enough, let's compare with sbrk(0) or &end */
	extern char end;
	char *brk = sbrk(0) != (void *)-1 ? sbrk(0) : &end;
	/* differ from nolibc, both glibc and musl have no global _auxv */
	const unsigned long *test_auxv = (void *)-1;
#ifdef NOLIBC
	test_auxv = _auxv;
#endif

	for (test = min; test >= 0 && test <= max; test++) {
		int llen = 0; /* line length */

		/* avoid leaving empty lines below, this will insert holes into
		 * test numbers.
		 */
		switch (test + __LINE__ + 1) {
		CASE_TEST(argc);             EXPECT_GE(1, test_argc, 1); break;
		CASE_TEST(argv_addr);        EXPECT_PTRGT(1, test_argv, brk); break;
		CASE_TEST(argv_environ);     EXPECT_PTRLT(1, test_argv, environ); break;
		CASE_TEST(argv_total);       EXPECT_EQ(1, environ - test_argv - 1, test_argc ?: 1); break;
		CASE_TEST(argv0_addr);       EXPECT_PTRGT(1, argv0, brk); break;
		CASE_TEST(argv0_str);        EXPECT_STRNZ(1, argv0 > brk ? argv0 : NULL); break;
		CASE_TEST(argv0_len);        EXPECT_GE(1,  argv0 > brk ? strlen(argv0) : 0, 1); break;
		CASE_TEST(environ_addr);     EXPECT_PTRGT(1, environ, brk); break;
		CASE_TEST(environ_envp);     EXPECT_PTREQ(1, environ, test_envp); break;
		CASE_TEST(environ_auxv);     EXPECT_PTRLT(test_auxv != (void *)-1, environ, test_auxv); break;
		CASE_TEST(environ_total);    EXPECT_GE(test_auxv != (void *)-1, (void *)test_auxv - (void *)environ - 1, env_total); break;
		CASE_TEST(environ_HOME);     EXPECT_PTRNZ(1, getenv("HOME")); break;
		CASE_TEST(auxv_addr);        EXPECT_PTRGT(test_auxv != (void *)-1, test_auxv, brk); break;
		CASE_TEST(auxv_AT_UID);      EXPECT_EQ(1, getauxval(AT_UID), getuid()); break;
		CASE_TEST(constructor);      EXPECT_EQ(is_nolibc, constructor_test_value, 0x3); break;
		CASE_TEST(linkage_errno);    EXPECT_PTREQ(1, linkage_test_errno_addr(), &errno); break;
		CASE_TEST(linkage_constr);   EXPECT_EQ(1, linkage_test_constructor_test_value, 0x3); break;
		case __LINE__:
			return ret; /* must be last */
		/* note: do not set any defaults so as to permit holes above */
		}
	}
	return ret;
}


/* used by some syscall tests below */
int test_getdents64(const char *dir)
{
	char buffer[4096];
	int fd, ret;
	int err;

	ret = fd = open(dir, O_RDONLY | O_DIRECTORY, 0);
	if (ret < 0)
		return ret;

	ret = getdents64(fd, (void *)buffer, sizeof(buffer));
	err = errno;
	close(fd);

	errno = err;
	return ret;
}

static int test_dirent(void)
{
	int comm = 0, cmdline = 0;
	struct dirent dirent, *result;
	DIR *dir;
	int ret;

	dir = opendir("/proc/self");
	if (!dir)
		return 1;

	while (1) {
		errno = 0;
		ret = readdir_r(dir, &dirent, &result);
		if (ret != 0)
			return 1;
		if (!result)
			break;

		if (strcmp(dirent.d_name, "comm") == 0)
			comm++;
		else if (strcmp(dirent.d_name, "cmdline") == 0)
			cmdline++;
	}

	if (errno)
		return 1;

	ret = closedir(dir);
	if (ret)
		return 1;

	if (comm != 1 || cmdline != 1)
		return 1;

	return 0;
}

int test_getrandom(void)
{
	uint64_t rng = 0;
	ssize_t ret;

	ret = getrandom(&rng, sizeof(rng), GRND_NONBLOCK);
	if (ret == -1 && errno == EAGAIN)
		return 0; /* No entropy available yet */

	if (ret != sizeof(rng))
		return ret;

	if (!rng) {
		errno = EINVAL;
		return -1;
	}

	return 0;
}

int test_getpagesize(void)
{
	int x = getpagesize();
	int c;

	if (x < 0)
		return x;

#if defined(__x86_64__) || defined(__i386__) || defined(__i486__) || defined(__i586__) || defined(__i686__)
	/*
	 * x86 family is always 4K page.
	 */
	c = (x == 4096);
#elif defined(__aarch64__)
	/*
	 * Linux aarch64 supports three values of page size: 4K, 16K, and 64K
	 * which are selected at kernel compilation time.
	 */
	c = (x == 4096 || x == (16 * 1024) || x == (64 * 1024));
#else
	/*
	 * Assuming other architectures must have at least 4K page.
	 */
	c = (x >= 4096);
#endif

	return !c;
}

int test_file_stream(void)
{
	FILE *f;
	int r;

	f = fopen("/dev/null", "r");
	if (!f)
		return -1;

	errno = 0;
	r = fwrite("foo", 1, 3, f);
	if (r != 0 || errno != EBADF) {
		fclose(f);
		return -1;
	}

	r = fclose(f);
	if (r == EOF)
		return -1;

	return 0;
}

enum fork_type {
	FORK_STANDARD,
	FORK_VFORK,
};

int test_fork(enum fork_type type)
{
	int status;
	pid_t pid;

	/* flush the printf buffer to avoid child flush it */
	fflush(stdout);
	fflush(stderr);

	switch (type) {
	case FORK_STANDARD:
		pid = fork();
		break;
	case FORK_VFORK:
		pid = vfork();
		break;
	default:
		return 1;
	}

	switch (pid) {
	case -1:
		return 1;

	case 0:
		_exit(123);

	default:
		pid = waitpid(pid, &status, 0);

		return pid == -1 || !WIFEXITED(status) || WEXITSTATUS(status) != 123;
	}
}

int test_stat_timestamps(void)
{
	struct stat st;

	if (sizeof(st.st_atim.tv_sec) != sizeof(st.st_atime))
		return 1;

	if (stat("/proc/self/", &st) && stat(argv0, &st) && stat("/", &st))
		return 1;

	if (st.st_atim.tv_sec != st.st_atime || st.st_atim.tv_nsec > 1000000000)
		return 1;

	if (st.st_mtim.tv_sec != st.st_mtime || st.st_mtim.tv_nsec > 1000000000)
		return 1;

	if (st.st_ctim.tv_sec != st.st_ctime || st.st_ctim.tv_nsec > 1000000000)
		return 1;

	return 0;
}

int test_timer(void)
{
	struct itimerspec timerspec;
	struct sigevent evp;
	timer_t timer;
	int ret;

	evp.sigev_notify = SIGEV_NONE;

	ret = timer_create(CLOCK_MONOTONIC, &evp, &timer);
	if (ret)
		return ret;

	timerspec = (struct itimerspec) {
		.it_value.tv_sec = 1000000,
	};
	ret = timer_settime(timer, 0, &timerspec, NULL);
	if (ret)
		goto err;

	timerspec = (struct itimerspec) {
		.it_value.tv_sec = -1,
		.it_value.tv_nsec = -1,
		.it_interval.tv_sec = -1,
		.it_interval.tv_nsec = -1,
	};
	ret = timer_gettime(timer, &timerspec);
	if (ret)
		goto err;

	errno = EINVAL;
	ret = -1;

	if (timerspec.it_interval.tv_sec || timerspec.it_interval.tv_nsec)
		goto err;

	if (timerspec.it_value.tv_sec > 1000000)
		goto err;

	ret = timer_delete(timer);
	if (ret)
		return ret;

	return 0;

err:
	timer_delete(timer);
	return ret;
}

int test_timerfd(void)
{
	struct itimerspec timerspec;
	int timer, ret;

	timer = timerfd_create(CLOCK_MONOTONIC, 0);
	if (timer == -1)
		return -1;

	timerspec = (struct itimerspec) {
		.it_value.tv_sec = 1000000,
	};
	ret = timerfd_settime(timer, 0, &timerspec, NULL);
	if (ret)
		goto err;

	timerspec = (struct itimerspec) {
		.it_value.tv_sec = -1,
		.it_value.tv_nsec = -1,
		.it_interval.tv_sec = -1,
		.it_interval.tv_nsec = -1,
	};
	ret = timerfd_gettime(timer, &timerspec);
	if (ret)
		goto err;

	errno = EINVAL;
	ret = -1;

	if (timerspec.it_interval.tv_sec || timerspec.it_interval.tv_nsec)
		goto err;

	if (timerspec.it_value.tv_sec > 1000000)
		goto err;

	ret = close(timer);
	if (ret)
		return ret;

	return 0;

err:
	close(timer);
	return ret;
}

int test_uname(void)
{
	struct utsname buf;
	char osrelease[sizeof(buf.release)];
	ssize_t r;
	int fd;

	memset(&buf.domainname, 'P', sizeof(buf.domainname));

	if (uname(&buf))
		return 1;

	if (strncmp("Linux", buf.sysname, sizeof(buf.sysname)))
		return 1;

	fd = open("/proc/sys/kernel/osrelease", O_RDONLY);
	if (fd == -1)
		return 1;

	r = read(fd, osrelease, sizeof(osrelease));
	if (r == -1)
		return 1;

	close(fd);

	if (osrelease[r - 1] == '\n')
		r--;

	/* Validate one of the later fields to ensure field sizes are correct */
	if (strncmp(osrelease, buf.release, r))
		return 1;

	/* Ensure the field domainname is set, it is missing from struct old_utsname */
	if (strnlen(buf.domainname, sizeof(buf.domainname)) == sizeof(buf.domainname))
		return 1;

	return 0;
}

int test_mmap_munmap(void)
{
	int ret, fd, i, page_size;
	void *mem;
	size_t file_size, length, mem_length;
	off_t offset, pa_offset;
	struct stat stat_buf;
	const char * const files[] = {
		"/dev/zero",
		"/proc/1/exe", "/proc/self/exe",
		argv0,
		NULL
	};

	page_size = getpagesize();
	if (page_size < 0)
		return 1;

	/* find a right file to mmap, existed and accessible */
	for (i = 0; files[i] != NULL; i++) {
		ret = fd = open(files[i], O_RDONLY);
		if (ret == -1)
			continue;
		else
			break;
	}
	if (ret == -1)
		return 1;

	ret = stat(files[i], &stat_buf);
	if (ret == -1)
		goto end;

	/* file size of the special /dev/zero is 0, let's assign one manually */
	if (i == 0)
		file_size = 3*page_size;
	else
		file_size = stat_buf.st_size;

	offset = file_size - 1;
	if (offset < 0)
		offset = 0;
	length = file_size - offset;
	pa_offset = offset & ~(page_size - 1);
	mem_length = length + offset - pa_offset;

	mem = mmap(NULL, mem_length, PROT_READ, MAP_SHARED, fd, pa_offset);
	if (mem == MAP_FAILED) {
		ret = 1;
		goto end;
	}

	mem = mremap(mem, mem_length, mem_length * 2, MREMAP_MAYMOVE, 0);
	if (mem == MAP_FAILED) {
		munmap(mem, mem_length);
		ret = 1;
		goto end;
	}

	ret = munmap(mem, mem_length * 2);

end:
	close(fd);
	return !!ret;
}

int test_pipe(void)
{
	const char *const msg = "hello, nolibc";
	int pipefd[2];
	char buf[32];
	size_t len;

	if (pipe(pipefd) == -1)
		return 1;

	write(pipefd[1], msg, strlen(msg));
	close(pipefd[1]);
	len = read(pipefd[0], buf, sizeof(buf));
	close(pipefd[0]);

	if (len != strlen(msg))
		return 1;

	return !!memcmp(buf, msg, len);
}

int test_rlimit(void)
{
	struct rlimit rlim = {
		.rlim_cur = 1 << 20,
		.rlim_max = 1 << 21,
	};
	int ret;

	ret = setrlimit(RLIMIT_CORE, &rlim);
	if (ret)
		return -1;

	rlim.rlim_cur = 0;
	rlim.rlim_max = 0;

	ret = getrlimit(RLIMIT_CORE, &rlim);
	if (ret)
		return -1;

	if (rlim.rlim_cur != 1 << 20)
		return -1;
	if (rlim.rlim_max != 1 << 21)
		return -1;

	return 0;
}

int test_openat(void)
{
	int dev, null;

	dev = openat(AT_FDCWD, "/dev", O_DIRECTORY);
	if (dev < 0)
		return -1;

	null = openat(dev, "null", O_RDONLY);
	close(dev);
	if (null < 0)
		return -1;

	close(null);
	return 0;
}

int test_namespace(void)
{
	int original_ns, new_ns, ret;
	ino_t original_ns_ino;
	struct stat stat_buf;

	original_ns = open("/proc/self/ns/uts", O_RDONLY);
	if (original_ns == -1)
		return -1;

	ret = fstat(original_ns, &stat_buf);
	if (ret)
		goto out;

	original_ns_ino = stat_buf.st_ino;

	ret = unshare(CLONE_NEWUTS);
	if (ret)
		goto out;

	new_ns = open("/proc/self/ns/uts", O_RDONLY);
	if (new_ns == -1) {
		ret = new_ns;
		goto out;
	}

	ret = fstat(new_ns, &stat_buf);
	close(new_ns);
	if (ret)
		goto out;

	if (stat_buf.st_ino == original_ns_ino) {
		errno = EINVAL;
		ret = -1;
		goto out;
	}

	ret = setns(original_ns, CLONE_NEWUTS);
	if (ret)
		goto out;

	new_ns = open("/proc/self/ns/uts", O_RDONLY);
	if (new_ns == -1) {
		ret = new_ns;
		goto out;
	}

	ret = fstat(new_ns, &stat_buf);
	if (ret)
		goto out;

	close(new_ns);

	if (stat_buf.st_ino != original_ns_ino) {
		errno = EINVAL;
		ret = -1;
		goto out;
	}

	ret = 0;

out:
	close(original_ns);
	return ret;
}

/* Run syscall tests between IDs <min> and <max>.
 * Return 0 on success, non-zero on failure.
 */
int run_syscall(int min, int max)
{
	struct timeval tv;
	struct timezone tz;
	struct timespec ts;
	struct stat stat_buf;
	int euid0;
	int proc;
	int test;
	int tmp;
	int ret = 0;
	void *p1, *p2;
	int has_gettid = 1;
	int has_brk;

	/* <proc> indicates whether or not /proc is mounted */
	proc = stat("/proc", &stat_buf) == 0;

	/* this will be used to skip certain tests that can't be run unprivileged */
	euid0 = geteuid() == 0;

	/* from 2.30, glibc provides gettid() */
#if defined(__GLIBC_MINOR__) && defined(__GLIBC__)
	has_gettid = __GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 30);
#endif

	/* on musl setting brk()/sbrk() always fails */
	has_brk = brk(0) == 0;

	for (test = min; test >= 0 && test <= max; test++) {
		int llen = 0; /* line length */

		/* avoid leaving empty lines below, this will insert holes into
		 * test numbers.
		 */
		switch (test + __LINE__ + 1) {
		CASE_TEST(access);            EXPECT_SYSZR(proc, access("/proc/self", R_OK)); break;
		CASE_TEST(access_bad);        EXPECT_SYSER(proc, access("/proc/self", W_OK), -1, EPERM); break;
		CASE_TEST(clock_getres);      EXPECT_SYSZR(1, clock_getres(CLOCK_MONOTONIC, &ts)); break;
		CASE_TEST(clock_gettime);     EXPECT_SYSZR(1, clock_gettime(CLOCK_MONOTONIC, &ts)); break;
		CASE_TEST(clock_settime);     EXPECT_SYSER(1, clock_settime(CLOCK_MONOTONIC, &ts), -1, EINVAL); break;
		CASE_TEST(getpid);            EXPECT_SYSNE(1, getpid(), -1); break;
		CASE_TEST(getppid);           EXPECT_SYSNE(1, getppid(), -1); break;
		CASE_TEST(gettid);            EXPECT_SYSNE(has_gettid, gettid(), -1); break;
		CASE_TEST(getpgid_self);      EXPECT_SYSNE(1, getpgid(0), -1); break;
		CASE_TEST(getpgid_bad);       EXPECT_SYSER(1, getpgid(-1), -1, ESRCH); break;
		CASE_TEST(kill_0);            EXPECT_SYSZR(1, kill(getpid(), 0)); break;
		CASE_TEST(kill_CONT);         EXPECT_SYSZR(1, kill(getpid(), 0)); break;
		CASE_TEST(kill_BADPID);       EXPECT_SYSER(1, kill(INT_MAX, 0), -1, ESRCH); break;
		CASE_TEST(sbrk_0);            EXPECT_PTRNE(has_brk, sbrk(0), (void *)-1); break;
		CASE_TEST(sbrk);              if ((p1 = p2 = sbrk(4096)) != (void *)-1) p2 = sbrk(-4096); EXPECT_SYSZR(has_brk, (p2 == (void *)-1) || p2 == p1); break;
		CASE_TEST(brk);               EXPECT_SYSZR(has_brk, brk(sbrk(0))); break;
		CASE_TEST(chdir_root);        EXPECT_SYSZR(1, chdir("/")); chdir(getenv("PWD")); break;
		CASE_TEST(chdir_dot);         EXPECT_SYSZR(1, chdir(".")); break;
		CASE_TEST(chdir_blah);        EXPECT_SYSER(1, chdir("/blah"), -1, ENOENT); break;
		CASE_TEST(chmod_argv0);       EXPECT_SYSZR(1, chmod(argv0, 0555)); break;
		CASE_TEST(chmod_self);        EXPECT_SYSER(proc, chmod("/proc/self", 0555), -1, EPERM); break;
		CASE_TEST(chown_self);        EXPECT_SYSER(proc, chown("/proc/self", 0, 0), -1, EPERM); break;
		CASE_TEST(chroot_root);       EXPECT_SYSZR(euid0, chroot("/")); break;
		CASE_TEST(chroot_blah);       EXPECT_SYSER(1, chroot("/proc/self/blah"), -1, ENOENT); break;
		CASE_TEST(chroot_exe);        EXPECT_SYSER(1, chroot(argv0), -1, ENOTDIR); break;
		CASE_TEST(close_m1);          EXPECT_SYSER(1, close(-1), -1, EBADF); break;
		CASE_TEST(close_dup);         EXPECT_SYSZR(1, close(dup(0))); break;
		CASE_TEST(dup_0);             tmp = dup(0);  EXPECT_SYSNE(1, tmp, -1); close(tmp); break;
		CASE_TEST(dup_m1);            tmp = dup(-1); EXPECT_SYSER(1, tmp, -1, EBADF); if (tmp != -1) close(tmp); break;
		CASE_TEST(dup2_0);            tmp = dup2(0, 100);  EXPECT_SYSNE(1, tmp, -1); close(tmp); break;
		CASE_TEST(dup2_m1);           tmp = dup2(-1, 100); EXPECT_SYSER(1, tmp, -1, EBADF); if (tmp != -1) close(tmp); break;
		CASE_TEST(dup3_0);            tmp = dup3(0, 100, 0);  EXPECT_SYSNE(1, tmp, -1); close(tmp); break;
		CASE_TEST(dup3_m1);           tmp = dup3(-1, 100, 0); EXPECT_SYSER(1, tmp, -1, EBADF); if (tmp != -1) close(tmp); break;
		CASE_TEST(execve_root);       EXPECT_SYSER(1, execve("/", (char*[]){ [0] = "/", [1] = NULL }, NULL), -1, EACCES); break;
		CASE_TEST(file_stream);       EXPECT_SYSZR(1, test_file_stream()); break;
		CASE_TEST(fork);              EXPECT_SYSZR(1, test_fork(FORK_STANDARD)); break;
		CASE_TEST(getdents64_root);   EXPECT_SYSNE(1, test_getdents64("/"), -1); break;
		CASE_TEST(getdents64_null);   EXPECT_SYSER(1, test_getdents64("/dev/null"), -1, ENOTDIR); break;
		CASE_TEST(directories);       EXPECT_SYSZR(proc, test_dirent()); break;
		CASE_TEST(getrandom);         EXPECT_SYSZR(1, test_getrandom()); break;
		CASE_TEST(gettimeofday_tv);   EXPECT_SYSZR(1, gettimeofday(&tv, NULL)); break;
		CASE_TEST(gettimeofday_tv_tz);EXPECT_SYSZR(1, gettimeofday(&tv, &tz)); break;
		CASE_TEST(getpagesize);       EXPECT_SYSZR(1, test_getpagesize()); break;
		CASE_TEST(ioctl_tiocinq);     EXPECT_SYSZR(1, ioctl(0, TIOCINQ, &tmp)); break;
		CASE_TEST(link_root1);        EXPECT_SYSER(1, link("/", "/"), -1, EEXIST); break;
		CASE_TEST(link_blah);         EXPECT_SYSER(1, link("/proc/self/blah", "/blah"), -1, ENOENT); break;
		CASE_TEST(link_dir);          EXPECT_SYSER(euid0, link("/", "/blah"), -1, EPERM); break;
		CASE_TEST(link_cross);        EXPECT_SYSER(proc, link("/proc/self/cmdline", "/blah"), -1, EXDEV); break;
		CASE_TEST(lseek_m1);          EXPECT_SYSER(1, lseek(-1, 0, SEEK_SET), -1, EBADF); break;
		CASE_TEST(lseek_0);           EXPECT_SYSER(1, lseek(0, 0, SEEK_SET), -1, ESPIPE); break;
		CASE_TEST(mkdir_root);        EXPECT_SYSER(1, mkdir("/", 0755), -1, EEXIST); break;
		CASE_TEST(mmap_bad);          EXPECT_PTRER(1, mmap(NULL, 0, PROT_READ, MAP_PRIVATE, 0, 0), MAP_FAILED, EINVAL); break;
		CASE_TEST(munmap_bad);        EXPECT_SYSER(1, munmap(NULL, 0), -1, EINVAL); break;
		CASE_TEST(mmap_munmap_good);  EXPECT_SYSZR(1, test_mmap_munmap()); break;
		CASE_TEST(nanosleep);         ts.tv_nsec = -1; EXPECT_SYSER(1, nanosleep(&ts, NULL), -1, EINVAL); break;
		CASE_TEST(open_tty);          EXPECT_SYSNE(1, tmp = open("/dev/null", O_RDONLY), -1); if (tmp != -1) close(tmp); break;
		CASE_TEST(open_blah);         EXPECT_SYSER(1, tmp = open("/proc/self/blah", O_RDONLY), -1, ENOENT); if (tmp != -1) close(tmp); break;
		CASE_TEST(openat_dir);        EXPECT_SYSZR(1, test_openat()); break;
		CASE_TEST(pipe);              EXPECT_SYSZR(1, test_pipe()); break;
		CASE_TEST(poll_null);         EXPECT_SYSZR(1, poll(NULL, 0, 0)); break;
		CASE_TEST(poll_stdout);       EXPECT_SYSNE(1, ({ struct pollfd fds = { 1, POLLOUT, 0}; poll(&fds, 1, 0); }), -1); break;
		CASE_TEST(poll_fault);        EXPECT_SYSER(1, poll(NULL, 1, 0), -1, EFAULT); break;
		CASE_TEST(prctl);             EXPECT_SYSER(1, prctl(PR_SET_NAME, (unsigned long)NULL, 0, 0, 0), -1, EFAULT); break;
		CASE_TEST(read_badf);         EXPECT_SYSER(1, read(-1, &tmp, 1), -1, EBADF); break;
		CASE_TEST(rlimit);            EXPECT_SYSZR(1, test_rlimit()); break;
		CASE_TEST(rmdir_blah);        EXPECT_SYSER(1, rmdir("/blah"), -1, ENOENT); break;
		CASE_TEST(sched_yield);       EXPECT_SYSZR(1, sched_yield()); break;
		CASE_TEST(select_null);       EXPECT_SYSZR(1, ({ struct timeval tv = { 0 }; select(0, NULL, NULL, NULL, &tv); })); break;
		CASE_TEST(select_stdout);     EXPECT_SYSNE(1, ({ fd_set fds; FD_ZERO(&fds); FD_SET(1, &fds); select(2, NULL, &fds, NULL, NULL); }), -1); break;
		CASE_TEST(select_fault);      EXPECT_SYSER(1, select(1, (void *)1, NULL, NULL, 0), -1, EFAULT); break;
		CASE_TEST(stat_blah);         EXPECT_SYSER(1, stat("/proc/self/blah", &stat_buf), -1, ENOENT); break;
		CASE_TEST(stat_fault);        EXPECT_SYSER(1, stat(NULL, &stat_buf), -1, EFAULT); break;
		CASE_TEST(stat_timestamps);   EXPECT_SYSZR(1, test_stat_timestamps()); break;
		CASE_TEST(symlink_root);      EXPECT_SYSER(1, symlink("/", "/"), -1, EEXIST); break;
		CASE_TEST(timer);             EXPECT_SYSZR(1, test_timer()); break;
		CASE_TEST(timerfd);           EXPECT_SYSZR(1, test_timerfd()); break;
		CASE_TEST(uname);             EXPECT_SYSZR(proc, test_uname()); break;
		CASE_TEST(uname_fault);       EXPECT_SYSER(1, uname(NULL), -1, EFAULT); break;
		CASE_TEST(unlink_root);       EXPECT_SYSER(1, unlink("/"), -1, EISDIR); break;
		CASE_TEST(unlink_blah);       EXPECT_SYSER(1, unlink("/proc/self/blah"), -1, ENOENT); break;
		CASE_TEST(vfork);             EXPECT_SYSZR(1, test_fork(FORK_VFORK)); break;
		CASE_TEST(wait_child);        EXPECT_SYSER(1, wait(&tmp), -1, ECHILD); break;
		CASE_TEST(waitpid_min);       EXPECT_SYSER(1, waitpid(INT_MIN, &tmp, WNOHANG), -1, ESRCH); break;
		CASE_TEST(waitpid_child);     EXPECT_SYSER(1, waitpid(getpid(), &tmp, WNOHANG), -1, ECHILD); break;
		CASE_TEST(write_badf);        EXPECT_SYSER(1, write(-1, &tmp, 1), -1, EBADF); break;
		CASE_TEST(write_zero);        EXPECT_SYSZR(1, write(1, &tmp, 0)); break;
		CASE_TEST(syscall_noargs);    EXPECT_SYSEQ(1, syscall(__NR_getpid), getpid()); break;
		CASE_TEST(syscall_args);      EXPECT_SYSER(1, syscall(__NR_statx, 0, NULL, 0, 0, NULL), -1, EFAULT); break;
		CASE_TEST(namespace);         EXPECT_SYSZR(euid0 && proc, test_namespace()); break;
		case __LINE__:
			return ret; /* must be last */
		/* note: do not set any defaults so as to permit holes above */
		}
	}
	return ret;
}

int test_difftime(void)
{
	if (difftime(200., 100.) != 100.)
		return 1;

	if (difftime(100., 200.) != -100.)
		return 1;

	return 0;
}

int run_stdlib(int min, int max)
{
	int test;
	int ret = 0;

	for (test = min; test >= 0 && test <= max; test++) {
		int llen = 0; /* line length */

		/* For functions that take a long buffer, like strlcat()
		 * Add some more chars after the \0, to test functions that overwrite the buffer set
		 * the \0 at the exact right position.
		 */
		char buf[11] = "test123456";
		buf[4] = '\0';


		/* avoid leaving empty lines below, this will insert holes into
		 * test numbers.
		 */
		switch (test + __LINE__ + 1) {
		CASE_TEST(getenv_TERM);        EXPECT_STRNZ(1, getenv("TERM")); break;
		CASE_TEST(getenv_blah);        EXPECT_STRZR(1, getenv("blah")); break;
		CASE_TEST(setcmp_blah_blah);   EXPECT_EQ(1, strcmp("blah", "blah"), 0); break;
		CASE_TEST(setcmp_blah_blah2);  EXPECT_NE(1, strcmp("blah", "blah2"), 0); break;
		CASE_TEST(setncmp_blah_blah);  EXPECT_EQ(1, strncmp("blah", "blah", 10), 0); break;
		CASE_TEST(setncmp_blah_blah4); EXPECT_EQ(1, strncmp("blah", "blah4", 4), 0); break;
		CASE_TEST(setncmp_blah_blah5); EXPECT_NE(1, strncmp("blah", "blah5", 5), 0); break;
		CASE_TEST(setncmp_blah_blah6); EXPECT_NE(1, strncmp("blah", "blah6", 6), 0); break;
		CASE_TEST(strchr_foobar_o);    EXPECT_STREQ(1, strchr("foobar", 'o'), "oobar"); break;
		CASE_TEST(strchr_foobar_z);    EXPECT_STRZR(1, strchr("foobar", 'z')); break;
		CASE_TEST(strrchr_foobar_o);   EXPECT_STREQ(1, strrchr("foobar", 'o'), "obar"); break;
		CASE_TEST(strrchr_foobar_z);   EXPECT_STRZR(1, strrchr("foobar", 'z')); break;
		CASE_TEST(strlcat_0);          EXPECT_STRBUFEQ(is_nolibc, strlcat(buf, "bar", 0), buf, 3, "test"); break;
		CASE_TEST(strlcat_1);          EXPECT_STRBUFEQ(is_nolibc, strlcat(buf, "bar", 1), buf, 4, "test"); break;
		CASE_TEST(strlcat_5);          EXPECT_STRBUFEQ(is_nolibc, strlcat(buf, "bar", 5), buf, 7, "test"); break;
		CASE_TEST(strlcat_6);          EXPECT_STRBUFEQ(is_nolibc, strlcat(buf, "bar", 6), buf, 7, "testb"); break;
		CASE_TEST(strlcat_7);          EXPECT_STRBUFEQ(is_nolibc, strlcat(buf, "bar", 7), buf, 7, "testba"); break;
		CASE_TEST(strlcat_8);          EXPECT_STRBUFEQ(is_nolibc, strlcat(buf, "bar", 8), buf, 7, "testbar"); break;
		CASE_TEST(strlcpy_0);          EXPECT_STRBUFEQ(is_nolibc, strlcpy(buf, "bar", 0), buf, 3, "test"); break;
		CASE_TEST(strlcpy_1);          EXPECT_STRBUFEQ(is_nolibc, strlcpy(buf, "bar", 1), buf, 3, ""); break;
		CASE_TEST(strlcpy_2);          EXPECT_STRBUFEQ(is_nolibc, strlcpy(buf, "bar", 2), buf, 3, "b"); break;
		CASE_TEST(strlcpy_3);          EXPECT_STRBUFEQ(is_nolibc, strlcpy(buf, "bar", 3), buf, 3, "ba"); break;
		CASE_TEST(strlcpy_4);          EXPECT_STRBUFEQ(is_nolibc, strlcpy(buf, "bar", 4), buf, 3, "bar"); break;
		CASE_TEST(strstr_foobar_foo);  EXPECT_STREQ(1, strstr("foobar", "foo"), "foobar"); break;
		CASE_TEST(strstr_foobar_bar);  EXPECT_STREQ(1, strstr("foobar", "bar"), "bar"); break;
		CASE_TEST(strstr_foobar_baz);  EXPECT_PTREQ(1, strstr("foobar", "baz"), NULL); break;
		CASE_TEST(memcmp_20_20);       EXPECT_EQ(1, memcmp("aaa\x20", "aaa\x20", 4), 0); break;
		CASE_TEST(memcmp_20_60);       EXPECT_LT(1, memcmp("aaa\x20", "aaa\x60", 4), 0); break;
		CASE_TEST(memcmp_60_20);       EXPECT_GT(1, memcmp("aaa\x60", "aaa\x20", 4), 0); break;
		CASE_TEST(memcmp_20_e0);       EXPECT_LT(1, memcmp("aaa\x20", "aaa\xe0", 4), 0); break;
		CASE_TEST(memcmp_e0_20);       EXPECT_GT(1, memcmp("aaa\xe0", "aaa\x20", 4), 0); break;
		CASE_TEST(memcmp_80_e0);       EXPECT_LT(1, memcmp("aaa\x80", "aaa\xe0", 4), 0); break;
		CASE_TEST(memcmp_e0_80);       EXPECT_GT(1, memcmp("aaa\xe0", "aaa\x80", 4), 0); break;
		CASE_TEST(limit_int8_max);          EXPECT_EQ(1, INT8_MAX,         (int8_t)          0x7f); break;
		CASE_TEST(limit_int8_min);          EXPECT_EQ(1, INT8_MIN,         (int8_t)          0x80); break;
		CASE_TEST(limit_uint8_max);         EXPECT_EQ(1, UINT8_MAX,        (uint8_t)         0xff); break;
		CASE_TEST(limit_int16_max);         EXPECT_EQ(1, INT16_MAX,        (int16_t)         0x7fff); break;
		CASE_TEST(limit_int16_min);         EXPECT_EQ(1, INT16_MIN,        (int16_t)         0x8000); break;
		CASE_TEST(limit_uint16_max);        EXPECT_EQ(1, UINT16_MAX,       (uint16_t)        0xffff); break;
		CASE_TEST(limit_int32_max);         EXPECT_EQ(1, INT32_MAX,        (int32_t)         0x7fffffff); break;
		CASE_TEST(limit_int32_min);         EXPECT_EQ(1, INT32_MIN,        (int32_t)         0x80000000); break;
		CASE_TEST(limit_uint32_max);        EXPECT_EQ(1, UINT32_MAX,       (uint32_t)        0xffffffff); break;
		CASE_TEST(limit_int64_max);         EXPECT_EQ(1, INT64_MAX,        (int64_t)         0x7fffffffffffffff); break;
		CASE_TEST(limit_int64_min);         EXPECT_EQ(1, INT64_MIN,        (int64_t)         0x8000000000000000); break;
		CASE_TEST(limit_uint64_max);        EXPECT_EQ(1, UINT64_MAX,       (uint64_t)        0xffffffffffffffff); break;
		CASE_TEST(limit_int_least8_max);    EXPECT_EQ(1, INT_LEAST8_MAX,   (int_least8_t)    0x7f); break;
		CASE_TEST(limit_int_least8_min);    EXPECT_EQ(1, INT_LEAST8_MIN,   (int_least8_t)    0x80); break;
		CASE_TEST(limit_uint_least8_max);   EXPECT_EQ(1, UINT_LEAST8_MAX,  (uint_least8_t)   0xff); break;
		CASE_TEST(limit_int_least16_max);   EXPECT_EQ(1, INT_LEAST16_MAX,  (int_least16_t)   0x7fff); break;
		CASE_TEST(limit_int_least16_min);   EXPECT_EQ(1, INT_LEAST16_MIN,  (int_least16_t)   0x8000); break;
		CASE_TEST(limit_uint_least16_max);  EXPECT_EQ(1, UINT_LEAST16_MAX, (uint_least16_t)  0xffff); break;
		CASE_TEST(limit_int_least32_max);   EXPECT_EQ(1, INT_LEAST32_MAX,  (int_least32_t)   0x7fffffff); break;
		CASE_TEST(limit_int_least32_min);   EXPECT_EQ(1, INT_LEAST32_MIN,  (int_least32_t)   0x80000000); break;
		CASE_TEST(limit_uint_least32_max);  EXPECT_EQ(1, UINT_LEAST32_MAX, (uint_least32_t)  0xffffffffU); break;
		CASE_TEST(limit_int_least64_min);   EXPECT_EQ(1, INT_LEAST64_MIN,  (int_least64_t)   0x8000000000000000LL); break;
		CASE_TEST(limit_int_least64_max);   EXPECT_EQ(1, INT_LEAST64_MAX,  (int_least64_t)   0x7fffffffffffffffLL); break;
		CASE_TEST(limit_uint_least64_max);  EXPECT_EQ(1, UINT_LEAST64_MAX, (uint_least64_t)  0xffffffffffffffffULL); break;
		CASE_TEST(limit_int_fast8_max);     EXPECT_EQ(1, INT_FAST8_MAX,    (int_fast8_t)     0x7f); break;
		CASE_TEST(limit_int_fast8_min);     EXPECT_EQ(1, INT_FAST8_MIN,    (int_fast8_t)     0x80); break;
		CASE_TEST(limit_uint_fast8_max);    EXPECT_EQ(1, UINT_FAST8_MAX,   (uint_fast8_t)    0xff); break;
		CASE_TEST(limit_int_fast16_min);    EXPECT_EQ(1, INT_FAST16_MIN,   (int_fast16_t)    SINT_MIN_OF_TYPE(int_fast16_t)); break;
		CASE_TEST(limit_int_fast16_max);    EXPECT_EQ(1, INT_FAST16_MAX,   (int_fast16_t)    SINT_MAX_OF_TYPE(int_fast16_t)); break;
		CASE_TEST(limit_uint_fast16_max);   EXPECT_EQ(1, UINT_FAST16_MAX,  (uint_fast16_t)   UINTPTR_MAX); break;
		CASE_TEST(limit_int_fast32_min);    EXPECT_EQ(1, INT_FAST32_MIN,   (int_fast32_t)    SINT_MIN_OF_TYPE(int_fast32_t)); break;
		CASE_TEST(limit_int_fast32_max);    EXPECT_EQ(1, INT_FAST32_MAX,   (int_fast32_t)    SINT_MAX_OF_TYPE(int_fast32_t)); break;
		CASE_TEST(limit_uint_fast32_max);   EXPECT_EQ(1, UINT_FAST32_MAX,  (uint_fast32_t)   UINTPTR_MAX); break;
		CASE_TEST(limit_int_fast64_min);    EXPECT_EQ(1, INT_FAST64_MIN,   (int_fast64_t)    INT64_MIN); break;
		CASE_TEST(limit_int_fast64_max);    EXPECT_EQ(1, INT_FAST64_MAX,   (int_fast64_t)    INT64_MAX); break;
		CASE_TEST(limit_uint_fast64_max);   EXPECT_EQ(1, UINT_FAST64_MAX,  (uint_fast64_t)   UINT64_MAX); break;
		CASE_TEST(sizeof_long_sane);        EXPECT_EQ(1, sizeof(long) == 8 || sizeof(long) == 4, 1); break;
		CASE_TEST(limit_intptr_min);        EXPECT_EQ(1, INTPTR_MIN,  sizeof(long) == 8 ? (intptr_t)  0x8000000000000000LL  : (intptr_t)  0x80000000); break;
		CASE_TEST(limit_intptr_max);        EXPECT_EQ(1, INTPTR_MAX,  sizeof(long) == 8 ? (intptr_t)  0x7fffffffffffffffLL  : (intptr_t)  0x7fffffff); break;
		CASE_TEST(limit_uintptr_max);       EXPECT_EQ(1, UINTPTR_MAX, sizeof(long) == 8 ? (uintptr_t) 0xffffffffffffffffULL : (uintptr_t) 0xffffffffU); break;
		CASE_TEST(limit_ptrdiff_min);       EXPECT_EQ(1, PTRDIFF_MIN, sizeof(long) == 8 ? (ptrdiff_t) 0x8000000000000000LL  : (ptrdiff_t) 0x80000000); break;
		CASE_TEST(limit_ptrdiff_max);       EXPECT_EQ(1, PTRDIFF_MAX, sizeof(long) == 8 ? (ptrdiff_t) 0x7fffffffffffffffLL  : (ptrdiff_t) 0x7fffffff); break;
		CASE_TEST(limit_size_max);          EXPECT_EQ(1, SIZE_MAX,    sizeof(long) == 8 ? (size_t)    0xffffffffffffffffULL : (size_t)    0xffffffffU); break;
		CASE_TEST(strtol_simple);           EXPECT_STRTOX(1, strtol, "35", 10, 35, -1, 0); break;
		CASE_TEST(strtol_positive);         EXPECT_STRTOX(1, strtol, "+35", 10, 35, -1, 0); break;
		CASE_TEST(strtol_negative);         EXPECT_STRTOX(1, strtol, "-35", 10, -35, -1, 0); break;
		CASE_TEST(strtol_hex_auto);         EXPECT_STRTOX(1, strtol, "0xFF", 0, 255, -1, 0); break;
		CASE_TEST(strtol_base36);           EXPECT_STRTOX(1, strtol, "12yZ", 36, 50507, -1, 0); break;
		CASE_TEST(strtol_cutoff);           EXPECT_STRTOX(1, strtol, "1234567890", 8, 342391, 7, 0); break;
		CASE_TEST(strtol_octal_auto);       EXPECT_STRTOX(1, strtol, "011", 0, 9, -1, 0); break;
		CASE_TEST(strtol_hex_00);           EXPECT_STRTOX(1, strtol, "0x00", 16, 0, -1, 0); break;
		CASE_TEST(strtol_hex_FF);           EXPECT_STRTOX(1, strtol, "FF", 16, 255, -1, 0); break;
		CASE_TEST(strtol_hex_ff);           EXPECT_STRTOX(1, strtol, "ff", 16, 255, -1, 0); break;
		CASE_TEST(strtol_hex_prefix);       EXPECT_STRTOX(1, strtol, "0xFF", 16, 255, -1, 0); break;
		CASE_TEST(strtol_trailer);          EXPECT_STRTOX(1, strtol, "35foo", 10, 35, 2, 0); break;
		CASE_TEST(strtol_overflow);         EXPECT_STRTOX(1, strtol, "0x8000000000000000", 16, LONG_MAX, -1, ERANGE); break;
		CASE_TEST(strtol_underflow);        EXPECT_STRTOX(1, strtol, "-0x8000000000000001", 16, LONG_MIN, -1, ERANGE); break;
		CASE_TEST(strtoul_negative);        EXPECT_STRTOX(1, strtoul, "-0x1", 16, ULONG_MAX, 4, 0); break;
		CASE_TEST(strtoul_overflow);        EXPECT_STRTOX(1, strtoul, "0x10000000000000000", 16, ULONG_MAX, -1, ERANGE); break;
		CASE_TEST(strerror_success);        EXPECT_STREQ(is_nolibc, strerror(0), "errno=0"); break;
		CASE_TEST(strerror_EINVAL);         EXPECT_STREQ(is_nolibc, strerror(EINVAL), "errno=22"); break;
		CASE_TEST(strerror_int_max);        EXPECT_STREQ(is_nolibc, strerror(INT_MAX), "errno=2147483647"); break;
		CASE_TEST(strerror_int_min);        EXPECT_STREQ(is_nolibc, strerror(INT_MIN), "errno=-2147483648"); break;
		CASE_TEST(tolower);                 EXPECT_EQ(1, tolower('A'), 'a'); break;
		CASE_TEST(tolower_noop);            EXPECT_EQ(1, tolower('a'), 'a'); break;
		CASE_TEST(toupper);                 EXPECT_EQ(1, toupper('a'), 'A'); break;
		CASE_TEST(toupper_noop);            EXPECT_EQ(1, toupper('A'), 'A'); break;
		CASE_TEST(abs);                     EXPECT_EQ(1, abs(-10), 10); break;
		CASE_TEST(abs_noop);                EXPECT_EQ(1, abs(10), 10); break;
		CASE_TEST(difftime);                EXPECT_ZR(1, test_difftime()); break;

		case __LINE__:
			return ret; /* must be last */
		/* note: do not set any defaults so as to permit holes above */
		}
	}
	return ret;
}

#define EXPECT_VFPRINTF(c, expected, fmt, ...)				\
	ret += expect_vfprintf(llen, c, expected, fmt, ##__VA_ARGS__)

static int expect_vfprintf(int llen, int c, const char *expected, const char *fmt, ...)
{
	char buf[100];
	va_list args;
	ssize_t w;
	int ret;


	va_start(args, fmt);
	/* Only allow writing 21 bytes, to test truncation */
	w = vsnprintf(buf, 21, fmt, args);
	va_end(args);

	if (w != c) {
		llen += printf(" written(%d) != %d", (int)w, c);
		result(llen, FAIL);
		return 1;
	}

	llen += printf(" \"%s\" = \"%s\"", expected, buf);
	ret = strncmp(expected, buf, c);

	result(llen, ret ? FAIL : OK);
	return ret;
}

static int test_scanf(void)
{
	unsigned long long ull;
	unsigned long ul;
	unsigned int u;
	long long ll;
	long l;
	void *p;
	int i;

	/* return __LINE__ to point to the specific failure */

	/* test EOF */
	if (sscanf("", "foo") != EOF)
		return __LINE__;

	/* test simple literal without placeholder */
	if (sscanf("foo", "foo") != 0)
		return __LINE__;

	/* test single placeholder */
	if (sscanf("123", "%d", &i) != 1)
		return __LINE__;

	if (i != 123)
		return __LINE__;

	/* test multiple place holders and separators */
	if (sscanf("a123b456c0x90", "a%db%uc%p", &i, &u, &p) != 3)
		return __LINE__;

	if (i != 123)
		return __LINE__;

	if (u != 456)
		return __LINE__;

	if (p != (void *)0x90)
		return __LINE__;

	/* test space handling */
	if (sscanf("a    b1", "a b%d", &i) != 1)
		return __LINE__;

	if (i != 1)
		return __LINE__;

	/* test literal percent */
	if (sscanf("a%1", "a%%%d", &i) != 1)
		return __LINE__;

	if (i != 1)
		return __LINE__;

	/* test stdint.h types */
	if (sscanf("1|2|3|4|5|6",
		   "%d|%ld|%lld|%u|%lu|%llu",
		   &i, &l, &ll, &u, &ul, &ull) != 6)
		return __LINE__;

	if (i != 1 || l != 2 || ll != 3 ||
	    u != 4 || ul != 5 || ull != 6)
		return __LINE__;

	return 0;
}

int test_strerror(void)
{
	char buf[100];
	ssize_t ret;

	memset(buf, 'A', sizeof(buf));

	errno = EINVAL;
	ret = snprintf(buf, sizeof(buf), "%m");
	if (is_nolibc) {
		if (ret < 6 || memcmp(buf, "errno=", 6))
			return 1;
	}

	return 0;
}

static int test_printf_error(void)
{
	int fd, ret, saved_errno;

	fd = open("/dev/full", O_RDWR);
	if (fd == -1)
		return 1;

	errno = 0;
	ret = dprintf(fd, "foo");
	saved_errno = errno;
	close(fd);

	if (ret != -1)
		return 2;

	if (saved_errno != ENOSPC)
		return 3;

	return 0;
}

static int run_printf(int min, int max)
{
	int test;
	int ret = 0;

	for (test = min; test >= 0 && test <= max; test++) {
		int llen = 0; /* line length */

		/* avoid leaving empty lines below, this will insert holes into
		 * test numbers.
		 */
		switch (test + __LINE__ + 1) {
		CASE_TEST(empty);        EXPECT_VFPRINTF(0, "", ""); break;
		CASE_TEST(simple);       EXPECT_VFPRINTF(3, "foo", "foo"); break;
		CASE_TEST(string);       EXPECT_VFPRINTF(3, "foo", "%s", "foo"); break;
		CASE_TEST(number);       EXPECT_VFPRINTF(4, "1234", "%d", 1234); break;
		CASE_TEST(negnumber);    EXPECT_VFPRINTF(5, "-1234", "%d", -1234); break;
		CASE_TEST(unsigned);     EXPECT_VFPRINTF(5, "12345", "%u", 12345); break;
		CASE_TEST(char);         EXPECT_VFPRINTF(1, "c", "%c", 'c'); break;
		CASE_TEST(hex);          EXPECT_VFPRINTF(1, "f", "%x", 0xf); break;
		CASE_TEST(pointer);      EXPECT_VFPRINTF(3, "0x1", "%p", (void *) 0x1); break;
		CASE_TEST(uintmax_t);    EXPECT_VFPRINTF(20, "18446744073709551615", "%ju", 0xffffffffffffffffULL); break;
		CASE_TEST(intmax_t);     EXPECT_VFPRINTF(20, "-9223372036854775807", "%jd", 0x8000000000000001LL); break;
		CASE_TEST(truncation);   EXPECT_VFPRINTF(25, "01234567890123456789", "%s", "0123456789012345678901234"); break;
		CASE_TEST(string_width); EXPECT_VFPRINTF(10, "         1", "%10s", "1"); break;
		CASE_TEST(number_width); EXPECT_VFPRINTF(10, "         1", "%10d", 1); break;
		CASE_TEST(width_trunc);  EXPECT_VFPRINTF(25, "                    ", "%25d", 1); break;
		CASE_TEST(scanf);        EXPECT_ZR(1, test_scanf()); break;
		CASE_TEST(strerror);     EXPECT_ZR(1, test_strerror()); break;
		CASE_TEST(printf_error); EXPECT_ZR(1, test_printf_error()); break;
		case __LINE__:
			return ret; /* must be last */
		/* note: do not set any defaults so as to permit holes above */
		}
	}
	return ret;
}

__attribute__((no_sanitize("undefined")))
static int smash_stack(void)
{
	char buf[100];
	volatile char *ptr = buf;
	size_t i;

	for (i = 0; i < 200; i++)
		ptr[i] = 'P';

	return 1;
}

static int run_protection(int min __attribute__((unused)),
			  int max __attribute__((unused)))
{
	pid_t pid;
	int llen = 0, status;
	struct rlimit rlimit = { 0, 0 };

	llen += printf("0 -fstackprotector ");

#if !defined(_NOLIBC_STACKPROTECTOR)
	llen += printf("not supported");
	result(llen, SKIPPED);
	return 0;
#endif

#if defined(_NOLIBC_STACKPROTECTOR)
	if (!__stack_chk_guard) {
		llen += printf("__stack_chk_guard not initialized");
		result(llen, FAIL);
		return 1;
	}
#endif

	pid = -1;
	pid = fork();

	switch (pid) {
	case -1:
		llen += printf("fork()");
		result(llen, FAIL);
		return 1;

	case 0:
		close(STDOUT_FILENO);
		close(STDERR_FILENO);

		prctl(PR_SET_DUMPABLE, 0, 0, 0, 0);
		setrlimit(RLIMIT_CORE, &rlimit);
		smash_stack();
		return 1;

	default:
		pid = waitpid(pid, &status, 0);

		if (pid == -1 || !WIFSIGNALED(status) || WTERMSIG(status) != SIGABRT) {
			llen += printf("waitpid()");
			result(llen, FAIL);
			return 1;
		}
		result(llen, OK);
		return 0;
	}
}

/* prepare what needs to be prepared for pid 1 (stdio, /dev, /proc, etc) */
int prepare(void)
{
	struct stat stat_buf;

	/* It's possible that /dev doesn't even exist or was not mounted, so
	 * we'll try to create it, mount it, or create minimal entries into it.
	 * We want at least /dev/null and /dev/console.
	 */
	if (stat("/dev/.", &stat_buf) == 0 || mkdir("/dev", 0755) == 0) {
		if (stat("/dev/console", &stat_buf) != 0 ||
		    stat("/dev/null", &stat_buf) != 0 ||
		    stat("/dev/zero", &stat_buf) != 0 ||
		    stat("/dev/full", &stat_buf) != 0) {
			/* try devtmpfs first, otherwise fall back to manual creation */
			if (mount("/dev", "/dev", "devtmpfs", 0, 0) != 0) {
				mknod("/dev/console", 0600 | S_IFCHR, makedev(5, 1));
				mknod("/dev/null",    0666 | S_IFCHR, makedev(1, 3));
				mknod("/dev/zero",    0666 | S_IFCHR, makedev(1, 5));
				mknod("/dev/full",    0666 | S_IFCHR, makedev(1, 7));
			}
		}
	}

	/* If no /dev/console was found before calling init, stdio is closed so
	 * we need to reopen it from /dev/console. If it failed above, it will
	 * still fail here and we cannot emit a message anyway.
	 */
	if (close(dup(1)) == -1) {
		int fd = open("/dev/console", O_RDWR);

		if (fd >= 0) {
			if (fd != 0)
				dup2(fd, 0);
			if (fd != 1)
				dup2(fd, 1);
			if (fd != 2)
				dup2(fd, 2);
			if (fd > 2)
				close(fd);
			puts("\nSuccessfully reopened /dev/console.");
		}
	}

	/* try to mount /proc if not mounted. Silently fail otherwise */
	if (stat("/proc/.", &stat_buf) == 0 || mkdir("/proc", 0755) == 0) {
		if (stat("/proc/self", &stat_buf) != 0) {
			/* If not mountable, remove /proc completely to avoid misuse */
			if (mount("none", "/proc", "proc", 0, 0) != 0)
				rmdir("/proc");
		}
	}

	/* some tests rely on a writable /tmp */
	mkdir("/tmp", 0755);

	return 0;
}

/* This is the definition of known test names, with their functions */
static const struct test test_names[] = {
	/* add new tests here */
	{ .name = "startup",    .func = run_startup    },
	{ .name = "syscall",    .func = run_syscall    },
	{ .name = "stdlib",     .func = run_stdlib     },
	{ .name = "printf",     .func = run_printf     },
	{ .name = "protection", .func = run_protection },
	{ 0 }
};

static int is_setting_valid(char *test)
{
	int idx, len, test_len, valid = 0;
	char delimiter;

	if (!test)
		return valid;

	test_len = strlen(test);

	for (idx = 0; test_names[idx].name; idx++) {
		len = strlen(test_names[idx].name);
		if (test_len < len)
			continue;

		if (strncmp(test, test_names[idx].name, len) != 0)
			continue;

		delimiter = test[len];
		if (delimiter != ':' && delimiter != ',' && delimiter != '\0')
			continue;

		valid = 1;
		break;
	}

	return valid;
}

int main(int argc, char **argv, char **envp)
{
	int min = 0;
	int max = INT_MAX;
	int ret = 0;
	int err;
	int idx;
	char *test;

	argv0 = argv[0];
	test_argc = argc;
	test_argv = argv;
	test_envp = envp;

	/* when called as init, it's possible that no console was opened, for
	 * example if no /dev file system was provided. We'll check that fd#1
	 * was opened, and if not we'll attempt to create and open /dev/console
	 * and /dev/null that we'll use for later tests.
	 */
	if (getpid() == 1)
		prepare();

	/* the definition of a series of tests comes from either argv[1] or the
	 * "NOLIBC_TEST" environment variable. It's made of a comma-delimited
	 * series of test names and optional ranges:
	 *    syscall:5-15[:.*],stdlib:8-10
	 */
	test = argv[1];
	if (!is_setting_valid(test))
		test = getenv("NOLIBC_TEST");

	if (is_setting_valid(test)) {
		char *comma, *colon, *dash, *value;

		do {
			comma = strchr(test, ',');
			if (comma)
				*(comma++) = '\0';

			colon = strchr(test, ':');
			if (colon)
				*(colon++) = '\0';

			for (idx = 0; test_names[idx].name; idx++) {
				if (strcmp(test, test_names[idx].name) == 0)
					break;
			}

			if (test_names[idx].name) {
				/* The test was named, it will be called at least
				 * once. We may have an optional range at <colon>
				 * here, which defaults to the full range.
				 */
				do {
					min = 0; max = INT_MAX;
					value = colon;
					if (value && *value) {
						colon = strchr(value, ':');
						if (colon)
							*(colon++) = '\0';

						dash = strchr(value, '-');
						if (dash)
							*(dash++) = '\0';

						/* support :val: :min-max: :min-: :-max: */
						if (*value)
							min = atoi(value);
						if (!dash)
							max = min;
						else if (*dash)
							max = atoi(dash);

						value = colon;
					}

					/* now's time to call the test */
					printf("Running test '%s'\n", test_names[idx].name);
					err = test_names[idx].func(min, max);
					ret += err;
					printf("Errors during this test: %d\n\n", err);
				} while (colon && *colon);
			} else
				printf("Ignoring unknown test name '%s'\n", test);

			test = comma;
		} while (test && *test);
	} else {
		/* no test mentioned, run everything */
		for (idx = 0; test_names[idx].name; idx++) {
			printf("Running test '%s'\n", test_names[idx].name);
			err = test_names[idx].func(min, max);
			ret += err;
			printf("Errors during this test: %d\n\n", err);
		}
	}

	printf("Total number of errors: %d\n", ret);

	if (getpid() == 1) {
		/* we're running as init, there's no other process on the
		 * system, thus likely started from a VM for a quick check.
		 * Exiting will provoke a kernel panic that may be reported
		 * as an error by Qemu or the hypervisor, while stopping
		 * cleanly will often be reported as a success. This allows
		 * to use the output of this program for bisecting kernels.
		 */
		printf("Leaving init with final status: %d\n", !!ret);
		if (ret == 0)
			reboot(RB_POWER_OFF);
#if defined(__x86_64__)
		/* QEMU started with "-device isa-debug-exit -no-reboot" will
		 * exit with status code 2N+1 when N is written to 0x501. We
		 * hard-code the syscall here as it's arch-dependent.
		 */
		else if (syscall(__NR_ioperm, 0x501, 1, 1) == 0)
			__asm__ volatile ("outb %%al, %%dx" :: "d"(0x501), "a"(0));
		/* if it does nothing, fall back to the regular panic */
#endif
	}

	printf("Exiting with status %d\n", !!ret);
	return !!ret;
}