blob: 8e421e1d6d365450947771828160753d83c4c60b [file] [log] [blame]
Jeff Dike5134d8f2008-02-08 04:22:08 -08001/*
2 * Copyright (C) 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3 * Licensed under the GPL
4 */
5
Jeff Dike0f80bc82005-09-16 19:27:50 -07006#include <stdio.h>
Jeff Dike0f80bc82005-09-16 19:27:50 -07007#include <stddef.h>
Jeff Dike5134d8f2008-02-08 04:22:08 -08008#include <stdlib.h>
Jeff Dike0f80bc82005-09-16 19:27:50 -07009#include <unistd.h>
10#include <errno.h>
Jeff Dike0f80bc82005-09-16 19:27:50 -070011#include <fcntl.h>
Jeff Dike5134d8f2008-02-08 04:22:08 -080012#include <string.h>
Liu Aleaxanderfb967ec2010-06-29 15:05:40 -070013#include <sys/stat.h>
Jeff Dike0f80bc82005-09-16 19:27:50 -070014#include <sys/mman.h>
Jeff Dike0f80bc82005-09-16 19:27:50 -070015#include <sys/param.h>
Jeff Dike5134d8f2008-02-08 04:22:08 -080016#include "init.h"
Jeff Dike5134d8f2008-02-08 04:22:08 -080017#include "os.h"
Jeff Dike0f80bc82005-09-16 19:27:50 -070018
Jeff Dike6bf79482007-02-10 01:44:18 -080019/* Modified by which_tmpdir, which is called during early boot */
Rob Landley966a082f2006-04-18 22:21:43 -070020static char *default_tmpdir = "/tmp";
Jeff Dike6bf79482007-02-10 01:44:18 -080021
22/*
23 * Modified when creating the physical memory file and when checking
24 * the tmp filesystem for usability, both happening during early boot.
25 */
Jeff Dike0f80bc82005-09-16 19:27:50 -070026static char *tempdir = NULL;
27
28static void __init find_tempdir(void)
29{
WANG Congc0a92902008-02-04 22:30:41 -080030 const char *dirs[] = { "TMP", "TEMP", "TMPDIR", NULL };
Jeff Dike0f80bc82005-09-16 19:27:50 -070031 int i;
32 char *dir = NULL;
33
Jeff Dike5134d8f2008-02-08 04:22:08 -080034 if (tempdir != NULL)
35 /* We've already been called */
Jeff Dike81999a02007-02-10 01:44:21 -080036 return;
Jeff Dike5134d8f2008-02-08 04:22:08 -080037 for (i = 0; dirs[i]; i++) {
Jeff Dike0f80bc82005-09-16 19:27:50 -070038 dir = getenv(dirs[i]);
Jeff Dike5134d8f2008-02-08 04:22:08 -080039 if ((dir != NULL) && (*dir != '\0'))
Jeff Dike0f80bc82005-09-16 19:27:50 -070040 break;
41 }
Jeff Dike5134d8f2008-02-08 04:22:08 -080042 if ((dir == NULL) || (*dir == '\0'))
Rob Landley966a082f2006-04-18 22:21:43 -070043 dir = default_tmpdir;
Jeff Dike0f80bc82005-09-16 19:27:50 -070044
45 tempdir = malloc(strlen(dir) + 2);
Jeff Dike5134d8f2008-02-08 04:22:08 -080046 if (tempdir == NULL) {
Jeff Dike0f80bc82005-09-16 19:27:50 -070047 fprintf(stderr, "Failed to malloc tempdir, "
48 "errno = %d\n", errno);
49 return;
50 }
51 strcpy(tempdir, dir);
52 strcat(tempdir, "/");
53}
54
Jeff Dike5134d8f2008-02-08 04:22:08 -080055/*
56 * This will return 1, with the first character in buf being the
Rob Landley966a082f2006-04-18 22:21:43 -070057 * character following the next instance of c in the file. This will
58 * read the file as needed. If there's an error, -errno is returned;
59 * if the end of the file is reached, 0 is returned.
60 */
WANG Congc0a92902008-02-04 22:30:41 -080061static int next(int fd, char *buf, size_t size, char c)
Rob Landley966a082f2006-04-18 22:21:43 -070062{
WANG Congc0a92902008-02-04 22:30:41 -080063 ssize_t n;
64 size_t len;
Rob Landley966a082f2006-04-18 22:21:43 -070065 char *ptr;
66
Jeff Dike5134d8f2008-02-08 04:22:08 -080067 while ((ptr = strchr(buf, c)) == NULL) {
Rob Landley966a082f2006-04-18 22:21:43 -070068 n = read(fd, buf, size - 1);
Jeff Dike5134d8f2008-02-08 04:22:08 -080069 if (n == 0)
Rob Landley966a082f2006-04-18 22:21:43 -070070 return 0;
Jeff Dike5134d8f2008-02-08 04:22:08 -080071 else if (n < 0)
Rob Landley966a082f2006-04-18 22:21:43 -070072 return -errno;
73
74 buf[n] = '\0';
75 }
76
77 ptr++;
Jeff Dikec2b7a4b2006-06-30 01:55:54 -070078 len = strlen(ptr);
79 memmove(buf, ptr, len + 1);
80
Jeff Dike5134d8f2008-02-08 04:22:08 -080081 /*
82 * Refill the buffer so that if there's a partial string that we care
Jeff Dikec2b7a4b2006-06-30 01:55:54 -070083 * about, it will be completed, and we can recognize it.
84 */
85 n = read(fd, &buf[len], size - len - 1);
Jeff Dike5134d8f2008-02-08 04:22:08 -080086 if (n < 0)
Jeff Dikec2b7a4b2006-06-30 01:55:54 -070087 return -errno;
88
89 buf[len + n] = '\0';
Rob Landley966a082f2006-04-18 22:21:43 -070090 return 1;
91}
92
Jeff Dike6bf79482007-02-10 01:44:18 -080093/* which_tmpdir is called only during early boot */
Rob Landley966a082f2006-04-18 22:21:43 -070094static int checked_tmpdir = 0;
95
Jeff Dike5134d8f2008-02-08 04:22:08 -080096/*
97 * Look for a tmpfs mounted at /dev/shm. I couldn't find a cleaner
Rob Landley966a082f2006-04-18 22:21:43 -070098 * way to do this than to parse /proc/mounts. statfs will return the
99 * same filesystem magic number and fs id for both /dev and /dev/shm
100 * when they are both tmpfs, so you can't tell if they are different
101 * filesystems. Also, there seems to be no other way of finding the
102 * mount point of a filesystem from within it.
103 *
104 * If a /dev/shm tmpfs entry is found, then we switch to using it.
105 * Otherwise, we stay with the default /tmp.
106 */
107static void which_tmpdir(void)
108{
109 int fd, found;
110 char buf[128] = { '\0' };
111
Jeff Dike5134d8f2008-02-08 04:22:08 -0800112 if (checked_tmpdir)
Rob Landley966a082f2006-04-18 22:21:43 -0700113 return;
114
115 checked_tmpdir = 1;
116
117 printf("Checking for tmpfs mount on /dev/shm...");
118
119 fd = open("/proc/mounts", O_RDONLY);
Jeff Dike5134d8f2008-02-08 04:22:08 -0800120 if (fd < 0) {
Rob Landley966a082f2006-04-18 22:21:43 -0700121 printf("failed to open /proc/mounts, errno = %d\n", errno);
122 return;
123 }
124
Jeff Dike5134d8f2008-02-08 04:22:08 -0800125 while (1) {
Jeff Dike91b165c2006-09-25 23:33:00 -0700126 found = next(fd, buf, ARRAY_SIZE(buf), ' ');
Jeff Dike5134d8f2008-02-08 04:22:08 -0800127 if (found != 1)
Rob Landley966a082f2006-04-18 22:21:43 -0700128 break;
129
Jeff Dike5134d8f2008-02-08 04:22:08 -0800130 if (!strncmp(buf, "/dev/shm", strlen("/dev/shm")))
Rob Landley966a082f2006-04-18 22:21:43 -0700131 goto found;
132
Jeff Dike91b165c2006-09-25 23:33:00 -0700133 found = next(fd, buf, ARRAY_SIZE(buf), '\n');
Jeff Dike5134d8f2008-02-08 04:22:08 -0800134 if (found != 1)
Rob Landley966a082f2006-04-18 22:21:43 -0700135 break;
136 }
137
138err:
Jeff Dike5134d8f2008-02-08 04:22:08 -0800139 if (found == 0)
Rob Landley966a082f2006-04-18 22:21:43 -0700140 printf("nothing mounted on /dev/shm\n");
Jeff Dike5134d8f2008-02-08 04:22:08 -0800141 else if (found < 0)
Rob Landley966a082f2006-04-18 22:21:43 -0700142 printf("read returned errno %d\n", -found);
143
Jeff Dike80c13742006-09-29 01:58:51 -0700144out:
145 close(fd);
146
Rob Landley966a082f2006-04-18 22:21:43 -0700147 return;
148
149found:
Jeff Dike91b165c2006-09-25 23:33:00 -0700150 found = next(fd, buf, ARRAY_SIZE(buf), ' ');
Jeff Dike5134d8f2008-02-08 04:22:08 -0800151 if (found != 1)
Rob Landley966a082f2006-04-18 22:21:43 -0700152 goto err;
153
Jeff Dike5134d8f2008-02-08 04:22:08 -0800154 if (strncmp(buf, "tmpfs", strlen("tmpfs"))) {
Rob Landley966a082f2006-04-18 22:21:43 -0700155 printf("not tmpfs\n");
Jeff Dike80c13742006-09-29 01:58:51 -0700156 goto out;
Rob Landley966a082f2006-04-18 22:21:43 -0700157 }
158
159 printf("OK\n");
160 default_tmpdir = "/dev/shm";
Jeff Dike80c13742006-09-29 01:58:51 -0700161 goto out;
Rob Landley966a082f2006-04-18 22:21:43 -0700162}
163
Jeff Dike5134d8f2008-02-08 04:22:08 -0800164static int __init make_tempfile(const char *template, char **out_tempname,
165 int do_unlink)
Jeff Dike0f80bc82005-09-16 19:27:50 -0700166{
Paolo 'Blaisorblade' Giarrusso87276f72006-04-10 22:53:39 -0700167 char *tempname;
Jeff Dike0f80bc82005-09-16 19:27:50 -0700168 int fd;
169
Rob Landley966a082f2006-04-18 22:21:43 -0700170 which_tmpdir();
Paolo 'Blaisorblade' Giarrusso87276f72006-04-10 22:53:39 -0700171 tempname = malloc(MAXPATHLEN);
Jim Meyering11a7ac22008-02-08 04:22:09 -0800172 if (tempname == NULL)
173 return -1;
Paolo 'Blaisorblade' Giarrusso87276f72006-04-10 22:53:39 -0700174
Jeff Dike0f80bc82005-09-16 19:27:50 -0700175 find_tempdir();
Jim Meyering11a7ac22008-02-08 04:22:09 -0800176 if ((tempdir == NULL) || (strlen(tempdir) >= MAXPATHLEN))
Davidlohr Bueso2a6d0ac2011-07-25 17:12:52 -0700177 goto out;
Jim Meyering11a7ac22008-02-08 04:22:09 -0800178
Paolo 'Blaisorblade' Giarrusso87276f72006-04-10 22:53:39 -0700179 if (template[0] != '/')
Jeff Dike0f80bc82005-09-16 19:27:50 -0700180 strcpy(tempname, tempdir);
181 else
Paolo 'Blaisorblade' Giarrusso87276f72006-04-10 22:53:39 -0700182 tempname[0] = '\0';
WANG Congc9a30722008-02-04 22:30:35 -0800183 strncat(tempname, template, MAXPATHLEN-1-strlen(tempname));
Jeff Dike0f80bc82005-09-16 19:27:50 -0700184 fd = mkstemp(tempname);
Jeff Dike5134d8f2008-02-08 04:22:08 -0800185 if (fd < 0) {
Jeff Dike0f80bc82005-09-16 19:27:50 -0700186 fprintf(stderr, "open - cannot create %s: %s\n", tempname,
187 strerror(errno));
Paolo 'Blaisorblade' Giarrusso87276f72006-04-10 22:53:39 -0700188 goto out;
Jeff Dike0f80bc82005-09-16 19:27:50 -0700189 }
Jeff Dike5134d8f2008-02-08 04:22:08 -0800190 if (do_unlink && (unlink(tempname) < 0)) {
Jeff Dike0f80bc82005-09-16 19:27:50 -0700191 perror("unlink");
Davidlohr Bueso2a6d0ac2011-07-25 17:12:52 -0700192 goto close;
Jeff Dike0f80bc82005-09-16 19:27:50 -0700193 }
Jeff Dike5134d8f2008-02-08 04:22:08 -0800194 if (out_tempname) {
Paolo 'Blaisorblade' Giarrusso87276f72006-04-10 22:53:39 -0700195 *out_tempname = tempname;
Jim Meyering11a7ac22008-02-08 04:22:09 -0800196 } else
Paolo 'Blaisorblade' Giarrusso87276f72006-04-10 22:53:39 -0700197 free(tempname);
Jeff Dike81999a02007-02-10 01:44:21 -0800198 return fd;
Davidlohr Bueso2a6d0ac2011-07-25 17:12:52 -0700199close:
200 close(fd);
Paolo 'Blaisorblade' Giarrusso87276f72006-04-10 22:53:39 -0700201out:
202 free(tempname);
203 return -1;
Jeff Dike0f80bc82005-09-16 19:27:50 -0700204}
205
206#define TEMPNAME_TEMPLATE "vm_file-XXXXXX"
207
Jeff Dike5134d8f2008-02-08 04:22:08 -0800208static int __init create_tmp_file(unsigned long long len)
Jeff Dike0f80bc82005-09-16 19:27:50 -0700209{
210 int fd, err;
211 char zero;
212
213 fd = make_tempfile(TEMPNAME_TEMPLATE, NULL, 1);
Jeff Dike5134d8f2008-02-08 04:22:08 -0800214 if (fd < 0)
Jeff Dike0f80bc82005-09-16 19:27:50 -0700215 exit(1);
Jeff Dike0f80bc82005-09-16 19:27:50 -0700216
217 err = fchmod(fd, 0777);
Jeff Dike5134d8f2008-02-08 04:22:08 -0800218 if (err < 0) {
Jeff Dike512b6fb2007-10-16 01:27:11 -0700219 perror("fchmod");
Jeff Dike0f80bc82005-09-16 19:27:50 -0700220 exit(1);
221 }
222
Jeff Dike5134d8f2008-02-08 04:22:08 -0800223 /*
224 * Seek to len - 1 because writing a character there will
Jeff Dike190f4932006-06-30 01:55:55 -0700225 * increase the file size by one byte, to the desired length.
226 */
227 if (lseek64(fd, len - 1, SEEK_SET) < 0) {
Jeff Dike512b6fb2007-10-16 01:27:11 -0700228 perror("lseek64");
Jeff Dike0f80bc82005-09-16 19:27:50 -0700229 exit(1);
230 }
231
232 zero = 0;
233
Jeff Dikea61f3342007-05-06 14:51:35 -0700234 err = write(fd, &zero, 1);
Jeff Dike5134d8f2008-02-08 04:22:08 -0800235 if (err != 1) {
Jeff Dikea61f3342007-05-06 14:51:35 -0700236 perror("write");
Jeff Dike0f80bc82005-09-16 19:27:50 -0700237 exit(1);
238 }
239
Jeff Dike81999a02007-02-10 01:44:21 -0800240 return fd;
Jeff Dike0f80bc82005-09-16 19:27:50 -0700241}
242
Jeff Dike36e45462007-05-06 14:51:11 -0700243int __init create_mem_file(unsigned long long len)
Jeff Dike0f80bc82005-09-16 19:27:50 -0700244{
245 int err, fd;
246
Jeff Dike02dea082006-03-31 02:30:08 -0800247 fd = create_tmp_file(len);
Jeff Dike0f80bc82005-09-16 19:27:50 -0700248
Jeff Dike512b6fb2007-10-16 01:27:11 -0700249 err = os_set_exec_close(fd);
Jeff Dike5134d8f2008-02-08 04:22:08 -0800250 if (err < 0) {
Jeff Dike0f80bc82005-09-16 19:27:50 -0700251 errno = -err;
252 perror("exec_close");
253 }
Jeff Dike81999a02007-02-10 01:44:21 -0800254 return fd;
Jeff Dike0f80bc82005-09-16 19:27:50 -0700255}
Rob Landley966a082f2006-04-18 22:21:43 -0700256
257
Jeff Dike36e45462007-05-06 14:51:11 -0700258void __init check_tmpexec(void)
Rob Landley966a082f2006-04-18 22:21:43 -0700259{
260 void *addr;
261 int err, fd = create_tmp_file(UM_KERN_PAGE_SIZE);
262
263 addr = mmap(NULL, UM_KERN_PAGE_SIZE,
264 PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE, fd, 0);
265 printf("Checking PROT_EXEC mmap in %s...",tempdir);
266 fflush(stdout);
Jeff Dike5134d8f2008-02-08 04:22:08 -0800267 if (addr == MAP_FAILED) {
Rob Landley966a082f2006-04-18 22:21:43 -0700268 err = errno;
269 perror("failed");
WANG Congc9a30722008-02-04 22:30:35 -0800270 close(fd);
Jeff Dike5134d8f2008-02-08 04:22:08 -0800271 if (err == EPERM)
Rob Landley966a082f2006-04-18 22:21:43 -0700272 printf("%s must be not mounted noexec\n",tempdir);
273 exit(1);
274 }
275 printf("OK\n");
276 munmap(addr, UM_KERN_PAGE_SIZE);
277
278 close(fd);
279}