[deliverable/linux.git] / arch / um / os-Linux / umid.c

/*
 * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
 * Licensed under the GPL
 */

#include <stdio.h>
#include <stdlib.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <string.h>
#include <unistd.h>
#include <sys/stat.h>
#include <init.h>
#include <os.h>

#define UML_DIR "~/.uml/"

#define UMID_LEN 64

/* Changed by set_umid, which is run early in boot */
static char umid[UMID_LEN] = { 0 };

/* Changed by set_uml_dir and make_uml_dir, which are run early in boot */
static char *uml_dir = UML_DIR;

static int __init make_uml_dir(void)
{
	char dir[512] = { '\0' };
	int len, err;

	if (*uml_dir == '~') {
		char *home = getenv("HOME");

		err = -ENOENT;
		if (home == NULL) {
			printk(UM_KERN_ERR "make_uml_dir : no value in "
			       "environment for $HOME\n");
			goto err;
		}
		strlcpy(dir, home, sizeof(dir));
		uml_dir++;
	}
	strlcat(dir, uml_dir, sizeof(dir));
	len = strlen(dir);
	if (len > 0 && dir[len - 1] != '/')
		strlcat(dir, "/", sizeof(dir));

	err = -ENOMEM;
	uml_dir = malloc(strlen(dir) + 1);
	if (uml_dir == NULL) {
		printf("make_uml_dir : malloc failed, errno = %d\n", errno);
		goto err;
	}
	strcpy(uml_dir, dir);

	if ((mkdir(uml_dir, 0777) < 0) && (errno != EEXIST)) {
	        printf("Failed to mkdir '%s': %s\n", uml_dir, strerror(errno));
		err = -errno;
		goto err_free;
	}
	return 0;

err_free:
	free(uml_dir);
err:
	uml_dir = NULL;
	return err;
}

/*
 * Unlinks the files contained in @dir and then removes @dir.
 * Doesn't handle directory trees, so it's not like rm -rf, but almost such. We
 * ignore ENOENT errors for anything (they happen, strangely enough - possibly
 * due to races between multiple dying UML threads).
 */
static int remove_files_and_dir(char *dir)
{
	DIR *directory;
	struct dirent *ent;
	int len;
	char file[256];
	int ret;

	directory = opendir(dir);
	if (directory == NULL) {
		if (errno != ENOENT)
			return -errno;
		else
			return 0;
	}

	while ((ent = readdir(directory)) != NULL) {
		if (!strcmp(ent->d_name, ".") || !strcmp(ent->d_name, ".."))
			continue;
		len = strlen(dir) + sizeof("/") + strlen(ent->d_name) + 1;
		if (len > sizeof(file)) {
			ret = -E2BIG;
			goto out;
		}

		sprintf(file, "%s/%s", dir, ent->d_name);
		if (unlink(file) < 0 && errno != ENOENT) {
			ret = -errno;
			goto out;
		}
	}

	if (rmdir(dir) < 0 && errno != ENOENT) {
		ret = -errno;
		goto out;
	}

	ret = 0;
out:
	closedir(directory);
	return ret;
}

/*
 * This says that there isn't already a user of the specified directory even if
 * there are errors during the checking.  This is because if these errors
 * happen, the directory is unusable by the pre-existing UML, so we might as
 * well take it over.  This could happen either by
 * 	the existing UML somehow corrupting its umid directory
 * 	something other than UML sticking stuff in the directory
 *	this boot racing with a shutdown of the other UML
 * In any of these cases, the directory isn't useful for anything else.
 *
 * Boolean return: 1 if in use, 0 otherwise.
 */
static inline int is_umdir_used(char *dir)
{
	char file[strlen(uml_dir) + UMID_LEN + sizeof("/pid\0")];
	char pid[sizeof("nnnnn\0")], *end;
	int dead, fd, p, n, err;

	n = snprintf(file, sizeof(file), "%s/pid", dir);
	if (n >= sizeof(file)) {
		printk(UM_KERN_ERR "is_umdir_used - pid filename too long\n");
		err = -E2BIG;
		goto out;
	}

	dead = 0;
	fd = open(file, O_RDONLY);
	if (fd < 0) {
		fd = -errno;
		if (fd != -ENOENT) {
			printk(UM_KERN_ERR "is_umdir_used : couldn't open pid "
			       "file '%s', err = %d\n", file, -fd);
		}
		goto out;
	}

	err = 0;
	n = read(fd, pid, sizeof(pid));
	if (n < 0) {
		printk(UM_KERN_ERR "is_umdir_used : couldn't read pid file "
		       "'%s', err = %d\n", file, errno);
		goto out_close;
	} else if (n == 0) {
		printk(UM_KERN_ERR "is_umdir_used : couldn't read pid file "
		       "'%s', 0-byte read\n", file);
		goto out_close;
	}

	p = strtoul(pid, &end, 0);
	if (end == pid) {
		printk(UM_KERN_ERR "is_umdir_used : couldn't parse pid file "
		       "'%s', errno = %d\n", file, errno);
		goto out_close;
	}

	if ((kill(p, 0) == 0) || (errno != ESRCH)) {
		printk(UM_KERN_ERR "umid \"%s\" is already in use by pid %d\n",
		       umid, p);
		return 1;
	}

out_close:
	close(fd);
out:
	return 0;
}

/*
 * Try to remove the directory @dir unless it's in use.
 * Precondition: @dir exists.
 * Returns 0 for success, < 0 for failure in removal or if the directory is in
 * use.
 */
static int umdir_take_if_dead(char *dir)
{
	int ret;
	if (is_umdir_used(dir))
		return -EEXIST;

	ret = remove_files_and_dir(dir);
	if (ret) {
		printk(UM_KERN_ERR "is_umdir_used - remove_files_and_dir "
		       "failed with err = %d\n", ret);
	}
	return ret;
}

static void __init create_pid_file(void)
{
	char file[strlen(uml_dir) + UMID_LEN + sizeof("/pid\0")];
	char pid[sizeof("nnnnn\0")];
	int fd, n;

	if (umid_file_name("pid", file, sizeof(file)))
		return;

	fd = open(file, O_RDWR | O_CREAT | O_EXCL, 0644);
	if (fd < 0) {
		printk(UM_KERN_ERR "Open of machine pid file \"%s\" failed: "
		       "%s\n", file, strerror(errno));
		return;
	}

	snprintf(pid, sizeof(pid), "%d\n", getpid());
	n = write(fd, pid, strlen(pid));
	if (n != strlen(pid))
		printk(UM_KERN_ERR "Write of pid file failed - err = %d\n",
		       errno);

	close(fd);
}

int __init set_umid(char *name)
{
	if (strlen(name) > UMID_LEN - 1)
		return -E2BIG;

	strlcpy(umid, name, sizeof(umid));

	return 0;
}

/* Changed in make_umid, which is called during early boot */
static int umid_setup = 0;

static int __init make_umid(void)
{
	int fd, err;
	char tmp[256];

	if (umid_setup)
		return 0;

	make_uml_dir();

	if (*umid == '\0') {
		strlcpy(tmp, uml_dir, sizeof(tmp));
		strlcat(tmp, "XXXXXX", sizeof(tmp));
		fd = mkstemp(tmp);
		if (fd < 0) {
			printk(UM_KERN_ERR "make_umid - mkstemp(%s) failed: "
			       "%s\n", tmp, strerror(errno));
			err = -errno;
			goto err;
		}

		close(fd);

		set_umid(&tmp[strlen(uml_dir)]);

		/*
		 * There's a nice tiny little race between this unlink and
		 * the mkdir below.  It'd be nice if there were a mkstemp
		 * for directories.
		 */
		if (unlink(tmp)) {
			err = -errno;
			goto err;
		}
	}

	snprintf(tmp, sizeof(tmp), "%s%s", uml_dir, umid);
	err = mkdir(tmp, 0777);
	if (err < 0) {
		err = -errno;
		if (err != -EEXIST)
			goto err;

		if (umdir_take_if_dead(tmp) < 0)
			goto err;

		err = mkdir(tmp, 0777);
	}
	if (err) {
		err = -errno;
		printk(UM_KERN_ERR "Failed to create '%s' - err = %d\n", umid,
		       errno);
		goto err;
	}

	umid_setup = 1;

	create_pid_file();

	err = 0;
 err:
	return err;
}

static int __init make_umid_init(void)
{
	if (!make_umid())
		return 0;

	/*
	 * If initializing with the given umid failed, then try again with
	 * a random one.
	 */
	printk(UM_KERN_ERR "Failed to initialize umid \"%s\", trying with a "
	       "random umid\n", umid);
	*umid = '\0';
	make_umid();

	return 0;
}

__initcall(make_umid_init);

int __init umid_file_name(char *name, char *buf, int len)
{
	int n, err;

	err = make_umid();
	if (err)
		return err;

	n = snprintf(buf, len, "%s%s/%s", uml_dir, umid, name);
	if (n >= len) {
		printk(UM_KERN_ERR "umid_file_name : buffer too short\n");
		return -E2BIG;
	}

	return 0;
}

char *get_umid(void)
{
	return umid;
}

static int __init set_uml_dir(char *name, int *add)
{
	if (*name == '\0') {
		printf("uml_dir can't be an empty string\n");
		return 0;
	}

	if (name[strlen(name) - 1] == '/') {
		uml_dir = name;
		return 0;
	}

	uml_dir = malloc(strlen(name) + 2);
	if (uml_dir == NULL) {
		printf("Failed to malloc uml_dir - error = %d\n", errno);

		/*
		 * Return 0 here because do_initcalls doesn't look at
		 * the return value.
		 */
		return 0;
	}
	sprintf(uml_dir, "%s/", name);

	return 0;
}

__uml_setup("uml_dir=", set_uml_dir,
"uml_dir=<directory>\n"
"    The location to place the pid and umid files.\n\n"
);

static void remove_umid_dir(void)
{
	char dir[strlen(uml_dir) + UMID_LEN + 1], err;

	sprintf(dir, "%s%s", uml_dir, umid);
	err = remove_files_and_dir(dir);
	if (err)
		printf("remove_umid_dir - remove_files_and_dir failed with "
		       "err = %d\n", err);
}

__uml_exitcall(remove_umid_dir);
Commit	Line	Data
ba180fd4 JD	1	/*
	2	* Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
	3	* Licensed under the GPL
	4	*/
	5
2264c475	6	#include <stdio.h>
2264c475	7	#include <stdlib.h>
ba180fd4	8	#include <dirent.h>
2264c475	9	#include <errno.h>
ba180fd4	10	#include <fcntl.h>
2264c475	11	#include <signal.h>
ba180fd4 JD	12	#include <string.h>
ba180fd4 JD	13	#include <unistd.h>
2264c475	14	#include <sys/stat.h>
37185b33 AV	15	#include <init.h>
37185b33 AV	16	#include <os.h>
2264c475 JD	17
	18	#define UML_DIR "~/.uml/"
	19
	20	#define UMID_LEN 64
	21
	22	/* Changed by set_umid, which is run early in boot */
de5fe76e	23	static char umid[UMID_LEN] = { 0 };
2264c475 JD	24
	25	/* Changed by set_uml_dir and make_uml_dir, which are run early in boot */
	26	static char *uml_dir = UML_DIR;
	27
	28	static int __init make_uml_dir(void)
	29	{
	30	char dir[512] = { '\0' };
7eebe8a9	31	int len, err;
2264c475	32
ba180fd4	33	if (*uml_dir == '~') {
2264c475 JD	34	char *home = getenv("HOME");
2264c475 JD	35
7eebe8a9	36	err = -ENOENT;
ba180fd4 JD	37	if (home == NULL) {
	38	printk(UM_KERN_ERR "make_uml_dir : no value in "
	39	"environment for $HOME\n");
7eebe8a9	40	goto err;
2264c475 JD	41	}
	42	strlcpy(dir, home, sizeof(dir));
	43	uml_dir++;
	44	}
	45	strlcat(dir, uml_dir, sizeof(dir));
	46	len = strlen(dir);
	47	if (len > 0 && dir[len - 1] != '/')
	48	strlcat(dir, "/", sizeof(dir));
	49
7eebe8a9	50	err = -ENOMEM;
2264c475 JD	51	uml_dir = malloc(strlen(dir) + 1);
	52	if (uml_dir == NULL) {
	53	printf("make_uml_dir : malloc failed, errno = %d\n", errno);
7eebe8a9	54	goto err;
2264c475 JD	55	}
	56	strcpy(uml_dir, dir);
	57
ba180fd4	58	if ((mkdir(uml_dir, 0777) < 0) && (errno != EEXIST)) {
2264c475	59	printf("Failed to mkdir '%s': %s\n", uml_dir, strerror(errno));
7eebe8a9 JD	60	err = -errno;
7eebe8a9 JD	61	goto err_free;
2264c475 JD	62	}
2264c475 JD	63	return 0;
7eebe8a9 JD	64
	65	err_free:
	66	free(uml_dir);
	67	err:
	68	uml_dir = NULL;
	69	return err;
2264c475 JD	70	}
2264c475 JD	71
eb28931e PBG	72	/*
	73	* Unlinks the files contained in @dir and then removes @dir.
	74	* Doesn't handle directory trees, so it's not like rm -rf, but almost such. We
ba180fd4 JD	75	* ignore ENOENT errors for anything (they happen, strangely enough - possibly
ba180fd4 JD	76	* due to races between multiple dying UML threads).
eb28931e PBG	77	*/
eb28931e PBG	78	static int remove_files_and_dir(char *dir)
2264c475 JD	79	{
	80	DIR *directory;
	81	struct dirent *ent;
	82	int len;
	83	char file[256];
eb28931e	84	int ret;
2264c475 JD	85
2264c475 JD	86	directory = opendir(dir);
eb28931e PBG	87	if (directory == NULL) {
	88	if (errno != ENOENT)
	89	return -errno;
	90	else
	91	return 0;
	92	}
7eebe8a9	93
eb28931e PBG	94	while ((ent = readdir(directory)) != NULL) {
eb28931e PBG	95	if (!strcmp(ent->d_name, ".") \|\| !strcmp(ent->d_name, ".."))
2264c475 JD	96	continue;
2264c475 JD	97	len = strlen(dir) + sizeof("/") + strlen(ent->d_name) + 1;
eb28931e PBG	98	if (len > sizeof(file)) {
	99	ret = -E2BIG;
	100	goto out;
	101	}
7eebe8a9	102
2264c475	103	sprintf(file, "%s/%s", dir, ent->d_name);
eb28931e PBG	104	if (unlink(file) < 0 && errno != ENOENT) {
	105	ret = -errno;
	106	goto out;
	107	}
2264c475	108	}
7eebe8a9	109
eb28931e PBG	110	if (rmdir(dir) < 0 && errno != ENOENT) {
	111	ret = -errno;
	112	goto out;
	113	}
	114
	115	ret = 0;
	116	out:
	117	closedir(directory);
	118	return ret;
2264c475 JD	119	}
2264c475 JD	120
ba180fd4 JD	121	/*
ba180fd4 JD	122	* This says that there isn't already a user of the specified directory even if
7eebe8a9 JD	123	* there are errors during the checking. This is because if these errors
	124	* happen, the directory is unusable by the pre-existing UML, so we might as
	125	* well take it over. This could happen either by
	126	* the existing UML somehow corrupting its umid directory
	127	* something other than UML sticking stuff in the directory
	128	* this boot racing with a shutdown of the other UML
	129	* In any of these cases, the directory isn't useful for anything else.
912ad922 PBG	130	*
912ad922 PBG	131	* Boolean return: 1 if in use, 0 otherwise.
7eebe8a9	132	*/
912ad922	133	static inline int is_umdir_used(char *dir)
2264c475 JD	134	{
	135	char file[strlen(uml_dir) + UMID_LEN + sizeof("/pid\0")];
	136	char pid[sizeof("nnnnn\0")], *end;
7eebe8a9 JD	137	int dead, fd, p, n, err;
	138
	139	n = snprintf(file, sizeof(file), "%s/pid", dir);
ba180fd4 JD	140	if (n >= sizeof(file)) {
ba180fd4 JD	141	printk(UM_KERN_ERR "is_umdir_used - pid filename too long\n");
7eebe8a9 JD	142	err = -E2BIG;
	143	goto out;
	144	}
2264c475	145
2264c475	146	dead = 0;
7eebe8a9	147	fd = open(file, O_RDONLY);
ba180fd4	148	if (fd < 0) {
d84a19ce	149	fd = -errno;
ba180fd4 JD	150	if (fd != -ENOENT) {
	151	printk(UM_KERN_ERR "is_umdir_used : couldn't open pid "
	152	"file '%s', err = %d\n", file, -fd);
2264c475	153	}
7eebe8a9	154	goto out;
2264c475	155	}
7eebe8a9 JD	156
	157	err = 0;
	158	n = read(fd, pid, sizeof(pid));
ba180fd4 JD	159	if (n < 0) {
	160	printk(UM_KERN_ERR "is_umdir_used : couldn't read pid file "
	161	"'%s', err = %d\n", file, errno);
d84a19ce	162	goto out_close;
ba180fd4 JD	163	} else if (n == 0) {
	164	printk(UM_KERN_ERR "is_umdir_used : couldn't read pid file "
	165	"'%s', 0-byte read\n", file);
7eebe8a9 JD	166	goto out_close;
	167	}
	168
	169	p = strtoul(pid, &end, 0);
ba180fd4 JD	170	if (end == pid) {
	171	printk(UM_KERN_ERR "is_umdir_used : couldn't parse pid file "
	172	"'%s', errno = %d\n", file, errno);
7eebe8a9	173	goto out_close;
2264c475	174	}
7eebe8a9	175
ba180fd4 JD	176	if ((kill(p, 0) == 0) \|\| (errno != ESRCH)) {
	177	printk(UM_KERN_ERR "umid \"%s\" is already in use by pid %d\n",
	178	umid, p);
7eebe8a9	179	return 1;
1fbbd684	180	}
7eebe8a9	181
d84a19ce	182	out_close:
7eebe8a9	183	close(fd);
d84a19ce	184	out:
7eebe8a9	185	return 0;
2264c475 JD	186	}
2264c475 JD	187
912ad922 PBG	188	/*
	189	* Try to remove the directory @dir unless it's in use.
	190	* Precondition: @dir exists.
	191	* Returns 0 for success, < 0 for failure in removal or if the directory is in
	192	* use.
	193	*/
	194	static int umdir_take_if_dead(char *dir)
	195	{
	196	int ret;
	197	if (is_umdir_used(dir))
	198	return -EEXIST;
	199
eb28931e	200	ret = remove_files_and_dir(dir);
912ad922	201	if (ret) {
ba180fd4 JD	202	printk(UM_KERN_ERR "is_umdir_used - remove_files_and_dir "
ba180fd4 JD	203	"failed with err = %d\n", ret);
912ad922 PBG	204	}
	205	return ret;
	206	}
	207
2264c475 JD	208	static void __init create_pid_file(void)
	209	{
	210	char file[strlen(uml_dir) + UMID_LEN + sizeof("/pid\0")];
	211	char pid[sizeof("nnnnn\0")];
	212	int fd, n;
	213
ba180fd4	214	if (umid_file_name("pid", file, sizeof(file)))
2264c475 JD	215	return;
2264c475 JD	216
7eebe8a9	217	fd = open(file, O_RDWR \| O_CREAT \| O_EXCL, 0644);
ba180fd4 JD	218	if (fd < 0) {
	219	printk(UM_KERN_ERR "Open of machine pid file \"%s\" failed: "
	220	"%s\n", file, strerror(errno));
2264c475 JD	221	return;
	222	}
	223
7eebe8a9 JD	224	snprintf(pid, sizeof(pid), "%d\n", getpid());
7eebe8a9 JD	225	n = write(fd, pid, strlen(pid));
ba180fd4 JD	226	if (n != strlen(pid))
	227	printk(UM_KERN_ERR "Write of pid file failed - err = %d\n",
	228	errno);
7eebe8a9 JD	229
7eebe8a9 JD	230	close(fd);
2264c475 JD	231	}
2264c475 JD	232
7eebe8a9	233	int __init set_umid(char *name)
2264c475	234	{
ba180fd4	235	if (strlen(name) > UMID_LEN - 1)
7eebe8a9 JD	236	return -E2BIG;
7eebe8a9 JD	237
2264c475 JD	238	strlcpy(umid, name, sizeof(umid));
	239
	240	return 0;
	241	}
	242
de5fe76e	243	/* Changed in make_umid, which is called during early boot */
2264c475 JD	244	static int umid_setup = 0;
2264c475 JD	245
99764fa4	246	static int __init make_umid(void)
2264c475 JD	247	{
	248	int fd, err;
	249	char tmp[256];
	250
ba180fd4	251	if (umid_setup)
7eebe8a9 JD	252	return 0;
7eebe8a9 JD	253
2264c475 JD	254	make_uml_dir();
2264c475 JD	255
ba180fd4	256	if (*umid == '\0') {
2264c475	257	strlcpy(tmp, uml_dir, sizeof(tmp));
7eebe8a9	258	strlcat(tmp, "XXXXXX", sizeof(tmp));
2264c475	259	fd = mkstemp(tmp);
ba180fd4 JD	260	if (fd < 0) {
	261	printk(UM_KERN_ERR "make_umid - mkstemp(%s) failed: "
	262	"%s\n", tmp, strerror(errno));
7eebe8a9 JD	263	err = -errno;
7eebe8a9 JD	264	goto err;
2264c475 JD	265	}
2264c475 JD	266
7eebe8a9 JD	267	close(fd);
	268
	269	set_umid(&tmp[strlen(uml_dir)]);
	270
ba180fd4 JD	271	/*
ba180fd4 JD	272	* There's a nice tiny little race between this unlink and
2264c475 JD	273	* the mkdir below. It'd be nice if there were a mkstemp
	274	* for directories.
	275	*/
ba180fd4	276	if (unlink(tmp)) {
7eebe8a9 JD	277	err = -errno;
	278	goto err;
	279	}
2264c475 JD	280	}
2264c475 JD	281
7eebe8a9	282	snprintf(tmp, sizeof(tmp), "%s%s", uml_dir, umid);
2264c475	283	err = mkdir(tmp, 0777);
ba180fd4	284	if (err < 0) {
7eebe8a9	285	err = -errno;
ba180fd4	286	if (err != -EEXIST)
7eebe8a9 JD	287	goto err;
7eebe8a9 JD	288
912ad922	289	if (umdir_take_if_dead(tmp) < 0)
7eebe8a9 JD	290	goto err;
	291
	292	err = mkdir(tmp, 0777);
2264c475	293	}
ba180fd4	294	if (err) {
1fbbd684	295	err = -errno;
ba180fd4 JD	296	printk(UM_KERN_ERR "Failed to create '%s' - err = %d\n", umid,
ba180fd4 JD	297	errno);
1fbbd684	298	goto err;
2264c475 JD	299	}
	300
	301	umid_setup = 1;
	302
	303	create_pid_file();
	304
1fbbd684	305	err = 0;
7eebe8a9 JD	306	err:
7eebe8a9 JD	307	return err;
2264c475 JD	308	}
	309
	310	static int __init make_umid_init(void)
	311	{
ba180fd4	312	if (!make_umid())
1fbbd684 JD	313	return 0;
1fbbd684 JD	314
ba180fd4 JD	315	/*
ba180fd4 JD	316	* If initializing with the given umid failed, then try again with
1fbbd684 JD	317	* a random one.
1fbbd684 JD	318	*/
ba180fd4 JD	319	printk(UM_KERN_ERR "Failed to initialize umid \"%s\", trying with a "
ba180fd4 JD	320	"random umid\n", umid);
1fbbd684	321	*umid = '\0';
7eebe8a9	322	make_umid();
2264c475	323
7eebe8a9	324	return 0;
2264c475 JD	325	}
	326
	327	__initcall(make_umid_init);
	328
	329	int __init umid_file_name(char name, char buf, int len)
	330	{
	331	int n, err;
	332
7eebe8a9	333	err = make_umid();
ba180fd4	334	if (err)
7eebe8a9	335	return err;
2264c475	336
7eebe8a9	337	n = snprintf(buf, len, "%s%s/%s", uml_dir, umid, name);
ba180fd4 JD	338	if (n >= len) {
ba180fd4 JD	339	printk(UM_KERN_ERR "umid_file_name : buffer too short\n");
7eebe8a9	340	return -E2BIG;
2264c475 JD	341	}
2264c475 JD	342
7eebe8a9	343	return 0;
2264c475 JD	344	}
2264c475 JD	345
7eebe8a9	346	char *get_umid(void)
2264c475	347	{
2264c475 JD	348	return umid;
	349	}
	350
	351	static int __init set_uml_dir(char name, int add)
	352	{
ba180fd4	353	if (*name == '\0') {
7eebe8a9 JD	354	printf("uml_dir can't be an empty string\n");
7eebe8a9 JD	355	return 0;
2264c475	356	}
7eebe8a9	357
ba180fd4	358	if (name[strlen(name) - 1] == '/') {
7eebe8a9 JD	359	uml_dir = name;
	360	return 0;
	361	}
	362
	363	uml_dir = malloc(strlen(name) + 2);
ba180fd4	364	if (uml_dir == NULL) {
7eebe8a9 JD	365	printf("Failed to malloc uml_dir - error = %d\n", errno);
7eebe8a9 JD	366
ba180fd4 JD	367	/*
ba180fd4 JD	368	* Return 0 here because do_initcalls doesn't look at
7eebe8a9 JD	369	* the return value.
	370	*/
	371	return 0;
	372	}
	373	sprintf(uml_dir, "%s/", name);
	374
	375	return 0;
2264c475 JD	376	}
	377
	378	__uml_setup("uml_dir=", set_uml_dir,
	379	"uml_dir=<directory>\n"
	380	" The location to place the pid and umid files.\n\n"
	381	);
	382
	383	static void remove_umid_dir(void)
	384	{
7eebe8a9	385	char dir[strlen(uml_dir) + UMID_LEN + 1], err;
2264c475 JD	386
2264c475 JD	387	sprintf(dir, "%s%s", uml_dir, umid);
eb28931e	388	err = remove_files_and_dir(dir);
ba180fd4	389	if (err)
eb28931e	390	printf("remove_umid_dir - remove_files_and_dir failed with "
7eebe8a9	391	"err = %d\n", err);
2264c475 JD	392	}
	393
	394	__uml_exitcall(remove_umid_dir);