summaryrefslogtreecommitdiff
path: root/arch/um/os-Linux/mem.c
blob: 71bb90a7606d0ebf8dab332fd874aa0e0f6d707b (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <stdarg.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/mman.h>
#include "kern_util.h"
#include "user.h"
#include "user_util.h"
#include "mem_user.h"
#include "init.h"
#include "os.h"
#include "tempfile.h"
#include "kern_constants.h"

#include <sys/param.h>

static char *tempdir = NULL;

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

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

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

/*
 * This proc still used in tt-mode
 * (file: kernel/tt/ptproxy/proxy.c, proc: start_debugger).
 * So it isn't 'static' yet.
 */
int make_tempfile(const char *template, char **out_tempname, int do_unlink)
{
	char *tempname;
	int fd;

	tempname = malloc(MAXPATHLEN);

	find_tempdir();
	if (template[0] != '/')
		strcpy(tempname, tempdir);
	else
		tempname[0] = '\0';
	strcat(tempname, template);
	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 out;
	}
	if(out_tempname){
		*out_tempname = tempname;
	} else {
		free(tempname);
	}
	return(fd);
out:
	free(tempname);
	return -1;
}

#define TEMPNAME_TEMPLATE "vm_file-XXXXXX"

/*
 * This proc is used in start_up.c
 * So it isn't 'static'.
 */
int 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("os_mode_fd");
		exit(1);
	}

        if (lseek64(fd, len, SEEK_SET) < 0) {
 		perror("os_seek_file");
		exit(1);
	}

	zero = 0;

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

	return(fd);
}

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

	fd = create_tmp_file(len);

	err = os_set_exec_close(fd, 1);
	if(err < 0){
		errno = -err;
		perror("exec_close");
	}
	return(fd);
}