[linux-block.git] / arch / um / os-Linux / mem.c

/*
 * Copyright (C) 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
 * Licensed under the GPL
 */

#include <stdio.h>
#include <stddef.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <sys/param.h>
#include <init.h>
#include <os.h>

/* Modified by which_tmpdir, which is called during early boot */
static char *default_tmpdir = "/tmp";

/*
 *  Modified when creating the physical memory file and when checking
 * the tmp filesystem for usability, both happening during early boot.
 */
static char *tempdir = NULL;

static void __init find_tempdir(void)
{
	const char *dirs[] = { "TMP", "TEMP", "TMPDIR", NULL };
	int i;
	char *dir = NULL;

	if (tempdir != NULL)
		/* We've already been called */
		return;
	for (i = 0; dirs[i]; i++) {
		dir = getenv(dirs[i]);
		if ((dir != NULL) && (*dir != '\0'))
			break;
	}
	if ((dir == NULL) || (*dir == '\0'))
		dir = default_tmpdir;

	tempdir = malloc(strlen(dir) + 2);
	if (tempdir == NULL) {
		fprintf(stderr, "Failed to malloc tempdir, "
			"errno = %d\n", errno);
		return;
	}
	strcpy(tempdir, dir);
	strcat(tempdir, "/");
}

/*
 * Remove bytes from the front of the buffer and refill it so that if there's a
 * partial string that we care about, it will be completed, and we can recognize
 * it.
 */
static int pop(int fd, char *buf, size_t size, size_t npop)
{
	ssize_t n;
	size_t len = strlen(&buf[npop]);

	memmove(buf, &buf[npop], len + 1);
	n = read(fd, &buf[len], size - len - 1);
	if (n < 0)
		return -errno;

	buf[len + n] = '\0';
	return 1;
}

/*
 * This will return 1, with the first character in buf being the
 * character following the next instance of c in the file.  This will
 * read the file as needed.  If there's an error, -errno is returned;
 * if the end of the file is reached, 0 is returned.
 */
static int next(int fd, char *buf, size_t size, char c)
{
	ssize_t n;
	char *ptr;

	while ((ptr = strchr(buf, c)) == NULL) {
		n = read(fd, buf, size - 1);
		if (n == 0)
			return 0;
		else if (n < 0)
			return -errno;

		buf[n] = '\0';
	}

	return pop(fd, buf, size, ptr - buf + 1);
}

/*
 * Decode an octal-escaped and space-terminated path of the form used by
 * /proc/mounts. May be used to decode a path in-place. "out" must be at least
 * as large as the input. The output is always null-terminated. "len" gets the
 * length of the output, excluding the trailing null. Returns 0 if a full path
 * was successfully decoded, otherwise an error.
 */
static int decode_path(const char *in, char *out, size_t *len)
{
	char *first = out;
	int c;
	int i;
	int ret = -EINVAL;
	while (1) {
		switch (*in) {
		case '\0':
			goto out;

		case ' ':
			ret = 0;
			goto out;

		case '\\':
			in++;
			c = 0;
			for (i = 0; i < 3; i++) {
				if (*in < '0' || *in > '7')
					goto out;
				c = (c << 3) | (*in++ - '0');
			}
			*(unsigned char *)out++ = (unsigned char) c;
			break;

		default:
			*out++ = *in++;
			break;
		}
	}

out:
	*out = '\0';
	*len = out - first;
	return ret;
}

/*
 * Computes the length of s when encoded with three-digit octal escape sequences
 * for the characters in chars.
 */
static size_t octal_encoded_length(const char *s, const char *chars)
{
	size_t len = strlen(s);
	while ((s = strpbrk(s, chars)) != NULL) {
		len += 3;
		s++;
	}

	return len;
}

enum {
	OUTCOME_NOTHING_MOUNTED,
	OUTCOME_TMPFS_MOUNT,
	OUTCOME_NON_TMPFS_MOUNT,
};

/* Read a line of /proc/mounts data looking for a tmpfs mount at "path". */
static int read_mount(int fd, char *buf, size_t bufsize, const char *path,
		      int *outcome)
{
	int found;
	int match;
	char *space;
	size_t len;

	enum {
		MATCH_NONE,
		MATCH_EXACT,
		MATCH_PARENT,
	};

	found = next(fd, buf, bufsize, ' ');
	if (found != 1)
		return found;

	/*
	 * If there's no following space in the buffer, then this path is
	 * truncated, so it can't be the one we're looking for.
	 */
	space = strchr(buf, ' ');
	if (space) {
		match = MATCH_NONE;
		if (!decode_path(buf, buf, &len)) {
			if (!strcmp(buf, path))
				match = MATCH_EXACT;
			else if (!strncmp(buf, path, len)
				 && (path[len] == '/' || !strcmp(buf, "/")))
				match = MATCH_PARENT;
		}

		found = pop(fd, buf, bufsize, space - buf + 1);
		if (found != 1)
			return found;

		switch (match) {
		case MATCH_EXACT:
			if (!strncmp(buf, "tmpfs", strlen("tmpfs")))
				*outcome = OUTCOME_TMPFS_MOUNT;
			else
				*outcome = OUTCOME_NON_TMPFS_MOUNT;
			break;

		case MATCH_PARENT:
			/* This mount obscures any previous ones. */
			*outcome = OUTCOME_NOTHING_MOUNTED;
			break;
		}
	}

	return next(fd, buf, bufsize, '\n');
}

/* which_tmpdir is called only during early boot */
static int checked_tmpdir = 0;

/*
 * Look for a tmpfs mounted at /dev/shm.  I couldn't find a cleaner
 * way to do this than to parse /proc/mounts.  statfs will return the
 * same filesystem magic number and fs id for both /dev and /dev/shm
 * when they are both tmpfs, so you can't tell if they are different
 * filesystems.  Also, there seems to be no other way of finding the
 * mount point of a filesystem from within it.
 *
 * If a /dev/shm tmpfs entry is found, then we switch to using it.
 * Otherwise, we stay with the default /tmp.
 */
static void which_tmpdir(void)
{
	int fd;
	int found;
	int outcome;
	char *path;
	char *buf;
	size_t bufsize;

	if (checked_tmpdir)
		return;

	checked_tmpdir = 1;

	printf("Checking for tmpfs mount on /dev/shm...");

	path = realpath("/dev/shm", NULL);
	if (!path) {
		printf("failed to check real path, errno = %d\n", errno);
		return;
	}
	printf("%s...", path);

	/*
	 * The buffer needs to be able to fit the full octal-escaped path, a
	 * space, and a trailing null in order to successfully decode it.
	 */
	bufsize = octal_encoded_length(path, " \t\n\\") + 2;

	if (bufsize < 128)
		bufsize = 128;

	buf = malloc(bufsize);
	if (!buf) {
		printf("malloc failed, errno = %d\n", errno);
		goto out;
	}
	buf[0] = '\0';

	fd = open("/proc/mounts", O_RDONLY);
	if (fd < 0) {
		printf("failed to open /proc/mounts, errno = %d\n", errno);
		goto out1;
	}

	outcome = OUTCOME_NOTHING_MOUNTED;
	while (1) {
		found = read_mount(fd, buf, bufsize, path, &outcome);
		if (found != 1)
			break;
	}

	if (found < 0) {
		printf("read returned errno %d\n", -found);
	} else {
		switch (outcome) {
		case OUTCOME_TMPFS_MOUNT:
			printf("OK\n");
			default_tmpdir = "/dev/shm";
			break;

		case OUTCOME_NON_TMPFS_MOUNT:
			printf("not tmpfs\n");
			break;

		default:
			printf("nothing mounted on /dev/shm\n");
			break;
		}
	}

	close(fd);
out1:
	free(buf);
out:
	free(path);
}

static int __init make_tempfile(const char *template, char **out_tempname,
				int do_unlink)
{
	char *tempname;
	int fd;

	which_tmpdir();
	tempname = malloc(MAXPATHLEN);
	if (tempname == NULL)
		return -1;

	find_tempdir();
	if ((tempdir == NULL) || (strlen(tempdir) >= MAXPATHLEN))
		goto out;

	if (template[0] != '/')
		strcpy(tempname, tempdir);
	else
		tempname[0] = '\0';
	strncat(tempname, template, MAXPATHLEN-1-strlen(tempname));
	fd = mkstemp(tempname);
	if (fd < 0) {
		fprintf(stderr, "open - cannot create %s: %s\n", tempname,
			strerror(errno));
		goto out;
	}
	if (do_unlink && (unlink(tempname) < 0)) {
		perror("unlink");
		goto close;
	}
	if (out_tempname) {
		*out_tempname = tempname;
	} else
		free(tempname);
	return fd;
close:
	close(fd);
out:
	free(tempname);
	return -1;
}

#define TEMPNAME_TEMPLATE "vm_file-XXXXXX"

static int __init create_tmp_file(unsigned long long len)
{
	int fd, err;
	char zero;

	fd = make_tempfile(TEMPNAME_TEMPLATE, NULL, 1);
	if (fd < 0)
		exit(1);

	err = fchmod(fd, 0777);
	if (err < 0) {
		perror("fchmod");
		exit(1);
	}

	/*
	 * Seek to len - 1 because writing a character there will
	 * increase the file size by one byte, to the desired length.
	 */
	if (lseek64(fd, len - 1, SEEK_SET) < 0) {
		perror("lseek64");
		exit(1);
	}

	zero = 0;

	err = write(fd, &zero, 1);
	if (err != 1) {
		perror("write");
		exit(1);
	}

	return fd;
}

int __init create_mem_file(unsigned long long len)
{
	int err, fd;

	fd = create_tmp_file(len);

	err = os_set_exec_close(fd);
	if (err < 0) {
		errno = -err;
		perror("exec_close");
	}
	return fd;
}


void __init check_tmpexec(void)
{
	void *addr;
	int err, fd = create_tmp_file(UM_KERN_PAGE_SIZE);

	addr = mmap(NULL, UM_KERN_PAGE_SIZE,
		    PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE, fd, 0);
	printf("Checking PROT_EXEC mmap in %s...",tempdir);
	fflush(stdout);
	if (addr == MAP_FAILED) {
		err = errno;
		perror("failed");
		close(fd);
		if (err == EPERM)
			printf("%s must be not mounted noexec\n",tempdir);
		exit(1);
	}
	printf("OK\n");
	munmap(addr, UM_KERN_PAGE_SIZE);

	close(fd);
}
Commit	Line	Data
5134d8fe JD	1	/*
	2	* Copyright (C) 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
	3	* Licensed under the GPL
	4	*/
	5
0f80bc85	6	#include <stdio.h>
0f80bc85	7	#include <stddef.h>
5134d8fe	8	#include <stdlib.h>
0f80bc85 JD	9	#include <unistd.h>
0f80bc85 JD	10	#include <errno.h>
0f80bc85	11	#include <fcntl.h>
5134d8fe	12	#include <string.h>
fb967ecc	13	#include <sys/stat.h>
0f80bc85	14	#include <sys/mman.h>
5134d8fe	15	#include <sys/param.h>
37185b33 AV	16	#include <init.h>
37185b33 AV	17	#include <os.h>
0f80bc85	18
6bf79482	19	/* Modified by which_tmpdir, which is called during early boot */
966a082f	20	static char *default_tmpdir = "/tmp";
6bf79482 JD	21
	22	/*
	23	* Modified when creating the physical memory file and when checking
	24	* the tmp filesystem for usability, both happening during early boot.
	25	*/
0f80bc85 JD	26	static char *tempdir = NULL;
	27
	28	static void __init find_tempdir(void)
	29	{
c0a9290e	30	const char *dirs[] = { "TMP", "TEMP", "TMPDIR", NULL };
0f80bc85 JD	31	int i;
	32	char *dir = NULL;
	33
5134d8fe JD	34	if (tempdir != NULL)
5134d8fe JD	35	/* We've already been called */
81999a01	36	return;
5134d8fe	37	for (i = 0; dirs[i]; i++) {
0f80bc85	38	dir = getenv(dirs[i]);
5134d8fe	39	if ((dir != NULL) && (*dir != '\0'))
0f80bc85 JD	40	break;
0f80bc85 JD	41	}
5134d8fe	42	if ((dir == NULL) \|\| (*dir == '\0'))
966a082f	43	dir = default_tmpdir;
0f80bc85 JD	44
0f80bc85 JD	45	tempdir = malloc(strlen(dir) + 2);
5134d8fe	46	if (tempdir == NULL) {
0f80bc85 JD	47	fprintf(stderr, "Failed to malloc tempdir, "
	48	"errno = %d\n", errno);
	49	return;
	50	}
	51	strcpy(tempdir, dir);
	52	strcat(tempdir, "/");
	53	}
	54
74735341 TS	55	/*
	56	* Remove bytes from the front of the buffer and refill it so that if there's a
	57	* partial string that we care about, it will be completed, and we can recognize
	58	* it.
	59	*/
	60	static int pop(int fd, char *buf, size_t size, size_t npop)
	61	{
	62	ssize_t n;
	63	size_t len = strlen(&buf[npop]);
	64
	65	memmove(buf, &buf[npop], len + 1);
	66	n = read(fd, &buf[len], size - len - 1);
	67	if (n < 0)
	68	return -errno;
	69
	70	buf[len + n] = '\0';
	71	return 1;
	72	}
	73
5134d8fe JD	74	/*
5134d8fe JD	75	* This will return 1, with the first character in buf being the
966a082f RL	76	* character following the next instance of c in the file. This will
	77	* read the file as needed. If there's an error, -errno is returned;
	78	* if the end of the file is reached, 0 is returned.
	79	*/
c0a9290e	80	static int next(int fd, char *buf, size_t size, char c)
966a082f	81	{
c0a9290e	82	ssize_t n;
966a082f RL	83	char *ptr;
966a082f RL	84
5134d8fe	85	while ((ptr = strchr(buf, c)) == NULL) {
966a082f	86	n = read(fd, buf, size - 1);
5134d8fe	87	if (n == 0)
966a082f	88	return 0;
5134d8fe	89	else if (n < 0)
966a082f RL	90	return -errno;
	91
	92	buf[n] = '\0';
	93	}
	94
74735341 TS	95	return pop(fd, buf, size, ptr - buf + 1);
	96	}
	97
	98	/*
	99	* Decode an octal-escaped and space-terminated path of the form used by
	100	* /proc/mounts. May be used to decode a path in-place. "out" must be at least
	101	* as large as the input. The output is always null-terminated. "len" gets the
	102	* length of the output, excluding the trailing null. Returns 0 if a full path
	103	* was successfully decoded, otherwise an error.
	104	*/
	105	static int decode_path(const char in, char out, size_t *len)
	106	{
	107	char *first = out;
	108	int c;
	109	int i;
	110	int ret = -EINVAL;
	111	while (1) {
	112	switch (*in) {
	113	case '\0':
	114	goto out;
	115
	116	case ' ':
	117	ret = 0;
	118	goto out;
	119
	120	case '\\':
	121	in++;
	122	c = 0;
	123	for (i = 0; i < 3; i++) {
	124	if (in < '0' \|\| in > '7')
	125	goto out;
	126	c = (c << 3) \| (*in++ - '0');
	127	}
	128	(unsigned char )out++ = (unsigned char) c;
	129	break;
	130
	131	default:
	132	out++ = in++;
	133	break;
	134	}
	135	}
	136
	137	out:
	138	*out = '\0';
	139	*len = out - first;
	140	return ret;
	141	}
	142
	143	/*
	144	* Computes the length of s when encoded with three-digit octal escape sequences
	145	* for the characters in chars.
	146	*/
	147	static size_t octal_encoded_length(const char s, const char chars)
	148	{
	149	size_t len = strlen(s);
	150	while ((s = strpbrk(s, chars)) != NULL) {
	151	len += 3;
	152	s++;
	153	}
	154
	155	return len;
	156	}
	157
	158	enum {
159	OUTCOME_NOTHING_MOUNTED,
160	OUTCOME_TMPFS_MOUNT,
161	OUTCOME_NON_TMPFS_MOUNT,
162	};
163
164	/* Read a line of /proc/mounts data looking for a tmpfs mount at "path". */
165	static int read_mount(int fd, char buf, size_t bufsize, const char path,
166	int *outcome)
167	{
168	int found;
169	int match;
170	char *space;
171	size_t len;
172
173	enum {
174	MATCH_NONE,
175	MATCH_EXACT,
176	MATCH_PARENT,
177	};
178
179	found = next(fd, buf, bufsize, ' ');
180	if (found != 1)
181	return found;
c2b7a4bb	182
5134d8fe	183	/*
74735341 TS	184	* If there's no following space in the buffer, then this path is
74735341 TS	185	* truncated, so it can't be the one we're looking for.
c2b7a4bb	186	*/
74735341 TS	187	space = strchr(buf, ' ');
	188	if (space) {
	189	match = MATCH_NONE;
	190	if (!decode_path(buf, buf, &len)) {
	191	if (!strcmp(buf, path))
	192	match = MATCH_EXACT;
	193	else if (!strncmp(buf, path, len)
	194	&& (path[len] == '/' \|\| !strcmp(buf, "/")))
	195	match = MATCH_PARENT;
	196	}
c2b7a4bb	197
74735341 TS	198	found = pop(fd, buf, bufsize, space - buf + 1);
	199	if (found != 1)
	200	return found;
	201
	202	switch (match) {
	203	case MATCH_EXACT:
	204	if (!strncmp(buf, "tmpfs", strlen("tmpfs")))
	205	*outcome = OUTCOME_TMPFS_MOUNT;
	206	else
	207	*outcome = OUTCOME_NON_TMPFS_MOUNT;
	208	break;
	209
	210	case MATCH_PARENT:
	211	/* This mount obscures any previous ones. */
	212	*outcome = OUTCOME_NOTHING_MOUNTED;
	213	break;
	214	}
	215	}
	216
	217	return next(fd, buf, bufsize, '\n');
966a082f RL	218	}
966a082f RL	219
6bf79482	220	/* which_tmpdir is called only during early boot */
966a082f RL	221	static int checked_tmpdir = 0;
966a082f RL	222
5134d8fe JD	223	/*
5134d8fe JD	224	* Look for a tmpfs mounted at /dev/shm. I couldn't find a cleaner
966a082f RL	225	* way to do this than to parse /proc/mounts. statfs will return the
	226	* same filesystem magic number and fs id for both /dev and /dev/shm
	227	* when they are both tmpfs, so you can't tell if they are different
	228	* filesystems. Also, there seems to be no other way of finding the
	229	* mount point of a filesystem from within it.
	230	*
	231	* If a /dev/shm tmpfs entry is found, then we switch to using it.
	232	* Otherwise, we stay with the default /tmp.
	233	*/
	234	static void which_tmpdir(void)
	235	{
74735341 TS	236	int fd;
	237	int found;
	238	int outcome;
	239	char *path;
	240	char *buf;
	241	size_t bufsize;
966a082f	242
5134d8fe	243	if (checked_tmpdir)
966a082f RL	244	return;
	245
	246	checked_tmpdir = 1;
	247
	248	printf("Checking for tmpfs mount on /dev/shm...");
	249
74735341 TS	250	path = realpath("/dev/shm", NULL);
	251	if (!path) {
	252	printf("failed to check real path, errno = %d\n", errno);
	253	return;
	254	}
	255	printf("%s...", path);
	256
	257	/*
	258	* The buffer needs to be able to fit the full octal-escaped path, a
	259	* space, and a trailing null in order to successfully decode it.
	260	*/
	261	bufsize = octal_encoded_length(path, " \t\n\\") + 2;
	262
	263	if (bufsize < 128)
	264	bufsize = 128;
	265
	266	buf = malloc(bufsize);
	267	if (!buf) {
	268	printf("malloc failed, errno = %d\n", errno);
	269	goto out;
	270	}
	271	buf[0] = '\0';
	272
966a082f	273	fd = open("/proc/mounts", O_RDONLY);
5134d8fe	274	if (fd < 0) {
966a082f	275	printf("failed to open /proc/mounts, errno = %d\n", errno);
74735341	276	goto out1;
966a082f RL	277	}
966a082f RL	278
74735341	279	outcome = OUTCOME_NOTHING_MOUNTED;
5134d8fe	280	while (1) {
74735341	281	found = read_mount(fd, buf, bufsize, path, &outcome);
5134d8fe	282	if (found != 1)
966a082f RL	283	break;
	284	}
	285
74735341	286	if (found < 0) {
966a082f	287	printf("read returned errno %d\n", -found);
74735341 TS	288	} else {
	289	switch (outcome) {
	290	case OUTCOME_TMPFS_MOUNT:
	291	printf("OK\n");
	292	default_tmpdir = "/dev/shm";
	293	break;
966a082f	294
74735341 TS	295	case OUTCOME_NON_TMPFS_MOUNT:
	296	printf("not tmpfs\n");
	297	break;
966a082f	298
74735341 TS	299	default:
	300	printf("nothing mounted on /dev/shm\n");
	301	break;
	302	}
966a082f RL	303	}
966a082f RL	304
74735341 TS	305	close(fd);
	306	out1:
	307	free(buf);
	308	out:
	309	free(path);
966a082f RL	310	}
966a082f RL	311
5134d8fe JD	312	static int __init make_tempfile(const char template, char *out_tempname,
5134d8fe JD	313	int do_unlink)
0f80bc85	314	{
87276f72	315	char *tempname;
0f80bc85 JD	316	int fd;
0f80bc85 JD	317
966a082f	318	which_tmpdir();
87276f72	319	tempname = malloc(MAXPATHLEN);
11a7ac23 JM	320	if (tempname == NULL)
11a7ac23 JM	321	return -1;
87276f72	322
0f80bc85	323	find_tempdir();
11a7ac23	324	if ((tempdir == NULL) \|\| (strlen(tempdir) >= MAXPATHLEN))
2a6d0ac1	325	goto out;
11a7ac23	326
87276f72	327	if (template[0] != '/')
0f80bc85 JD	328	strcpy(tempname, tempdir);
0f80bc85 JD	329	else
87276f72	330	tempname[0] = '\0';
c9a3072d	331	strncat(tempname, template, MAXPATHLEN-1-strlen(tempname));
0f80bc85	332	fd = mkstemp(tempname);
5134d8fe	333	if (fd < 0) {
0f80bc85 JD	334	fprintf(stderr, "open - cannot create %s: %s\n", tempname,
0f80bc85 JD	335	strerror(errno));
87276f72	336	goto out;
0f80bc85	337	}
5134d8fe	338	if (do_unlink && (unlink(tempname) < 0)) {
0f80bc85	339	perror("unlink");
2a6d0ac1	340	goto close;
0f80bc85	341	}
5134d8fe	342	if (out_tempname) {
87276f72	343	*out_tempname = tempname;
11a7ac23	344	} else
87276f72	345	free(tempname);
81999a01	346	return fd;
2a6d0ac1 DB	347	close:
2a6d0ac1 DB	348	close(fd);
87276f72 PBG	349	out:
	350	free(tempname);
	351	return -1;
0f80bc85 JD	352	}
	353
	354	#define TEMPNAME_TEMPLATE "vm_file-XXXXXX"
	355
5134d8fe	356	static int __init create_tmp_file(unsigned long long len)
0f80bc85 JD	357	{
	358	int fd, err;
	359	char zero;
	360
	361	fd = make_tempfile(TEMPNAME_TEMPLATE, NULL, 1);
5134d8fe	362	if (fd < 0)
0f80bc85	363	exit(1);
0f80bc85 JD	364
0f80bc85 JD	365	err = fchmod(fd, 0777);
5134d8fe	366	if (err < 0) {
512b6fb1	367	perror("fchmod");
0f80bc85 JD	368	exit(1);
	369	}
	370
5134d8fe JD	371	/*
5134d8fe JD	372	* Seek to len - 1 because writing a character there will
190f4939 JD	373	* increase the file size by one byte, to the desired length.
	374	*/
	375	if (lseek64(fd, len - 1, SEEK_SET) < 0) {
512b6fb1	376	perror("lseek64");
0f80bc85 JD	377	exit(1);
	378	}
	379
	380	zero = 0;
	381
a61f334f	382	err = write(fd, &zero, 1);
5134d8fe	383	if (err != 1) {
a61f334f	384	perror("write");
0f80bc85 JD	385	exit(1);
	386	}
	387
81999a01	388	return fd;
0f80bc85 JD	389	}
0f80bc85 JD	390
36e45463	391	int __init create_mem_file(unsigned long long len)
0f80bc85 JD	392	{
	393	int err, fd;
	394
02dea087	395	fd = create_tmp_file(len);
0f80bc85	396
512b6fb1	397	err = os_set_exec_close(fd);
5134d8fe	398	if (err < 0) {
0f80bc85 JD	399	errno = -err;
	400	perror("exec_close");
	401	}
81999a01	402	return fd;
0f80bc85	403	}
966a082f RL	404
966a082f RL	405
36e45463	406	void __init check_tmpexec(void)
966a082f RL	407	{
	408	void *addr;
	409	int err, fd = create_tmp_file(UM_KERN_PAGE_SIZE);
	410
	411	addr = mmap(NULL, UM_KERN_PAGE_SIZE,
	412	PROT_READ \| PROT_WRITE \| PROT_EXEC, MAP_PRIVATE, fd, 0);
	413	printf("Checking PROT_EXEC mmap in %s...",tempdir);
	414	fflush(stdout);
5134d8fe	415	if (addr == MAP_FAILED) {
966a082f RL	416	err = errno;
966a082f RL	417	perror("failed");
c9a3072d	418	close(fd);
5134d8fe	419	if (err == EPERM)
966a082f RL	420	printf("%s must be not mounted noexec\n",tempdir);
	421	exit(1);
	422	}
	423	printf("OK\n");
	424	munmap(addr, UM_KERN_PAGE_SIZE);
	425
	426	close(fd);
	427	}