Commit | Line | Data |
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0f80bc85 JD |
1 | #include <stdio.h> |
2 | #include <stdlib.h> | |
3 | #include <stddef.h> | |
4 | #include <stdarg.h> | |
5 | #include <unistd.h> | |
6 | #include <errno.h> | |
7 | #include <string.h> | |
8 | #include <fcntl.h> | |
9 | #include <sys/types.h> | |
10 | #include <sys/mman.h> | |
966a082f | 11 | #include <sys/statfs.h> |
0f80bc85 JD |
12 | #include "kern_util.h" |
13 | #include "user.h" | |
14 | #include "user_util.h" | |
15 | #include "mem_user.h" | |
16 | #include "init.h" | |
17 | #include "os.h" | |
18 | #include "tempfile.h" | |
19 | #include "kern_constants.h" | |
20 | ||
21 | #include <sys/param.h> | |
22 | ||
966a082f | 23 | static char *default_tmpdir = "/tmp"; |
0f80bc85 JD |
24 | static char *tempdir = NULL; |
25 | ||
26 | static void __init find_tempdir(void) | |
27 | { | |
28 | char *dirs[] = { "TMP", "TEMP", "TMPDIR", NULL }; | |
29 | int i; | |
30 | char *dir = NULL; | |
31 | ||
32 | if(tempdir != NULL) return; /* We've already been called */ | |
33 | for(i = 0; dirs[i]; i++){ | |
34 | dir = getenv(dirs[i]); | |
35 | if((dir != NULL) && (*dir != '\0')) | |
36 | break; | |
37 | } | |
38 | if((dir == NULL) || (*dir == '\0')) | |
966a082f | 39 | dir = default_tmpdir; |
0f80bc85 JD |
40 | |
41 | tempdir = malloc(strlen(dir) + 2); | |
42 | if(tempdir == NULL){ | |
43 | fprintf(stderr, "Failed to malloc tempdir, " | |
44 | "errno = %d\n", errno); | |
45 | return; | |
46 | } | |
47 | strcpy(tempdir, dir); | |
48 | strcat(tempdir, "/"); | |
49 | } | |
50 | ||
966a082f RL |
51 | /* This will return 1, with the first character in buf being the |
52 | * character following the next instance of c in the file. This will | |
53 | * read the file as needed. If there's an error, -errno is returned; | |
54 | * if the end of the file is reached, 0 is returned. | |
55 | */ | |
56 | static int next(int fd, char *buf, int size, char c) | |
57 | { | |
c2b7a4bb | 58 | int n, len; |
966a082f RL |
59 | char *ptr; |
60 | ||
61 | while((ptr = strchr(buf, c)) == NULL){ | |
62 | n = read(fd, buf, size - 1); | |
63 | if(n == 0) | |
64 | return 0; | |
65 | else if(n < 0) | |
66 | return -errno; | |
67 | ||
68 | buf[n] = '\0'; | |
69 | } | |
70 | ||
71 | ptr++; | |
c2b7a4bb JD |
72 | len = strlen(ptr); |
73 | memmove(buf, ptr, len + 1); | |
74 | ||
75 | /* Refill the buffer so that if there's a partial string that we care | |
76 | * about, it will be completed, and we can recognize it. | |
77 | */ | |
78 | n = read(fd, &buf[len], size - len - 1); | |
79 | if(n < 0) | |
80 | return -errno; | |
81 | ||
82 | buf[len + n] = '\0'; | |
966a082f RL |
83 | return 1; |
84 | } | |
85 | ||
86 | static int checked_tmpdir = 0; | |
87 | ||
88 | /* Look for a tmpfs mounted at /dev/shm. I couldn't find a cleaner | |
89 | * way to do this than to parse /proc/mounts. statfs will return the | |
90 | * same filesystem magic number and fs id for both /dev and /dev/shm | |
91 | * when they are both tmpfs, so you can't tell if they are different | |
92 | * filesystems. Also, there seems to be no other way of finding the | |
93 | * mount point of a filesystem from within it. | |
94 | * | |
95 | * If a /dev/shm tmpfs entry is found, then we switch to using it. | |
96 | * Otherwise, we stay with the default /tmp. | |
97 | */ | |
98 | static void which_tmpdir(void) | |
99 | { | |
100 | int fd, found; | |
101 | char buf[128] = { '\0' }; | |
102 | ||
103 | if(checked_tmpdir) | |
104 | return; | |
105 | ||
106 | checked_tmpdir = 1; | |
107 | ||
108 | printf("Checking for tmpfs mount on /dev/shm..."); | |
109 | ||
110 | fd = open("/proc/mounts", O_RDONLY); | |
111 | if(fd < 0){ | |
112 | printf("failed to open /proc/mounts, errno = %d\n", errno); | |
113 | return; | |
114 | } | |
115 | ||
116 | while(1){ | |
91b165c0 | 117 | found = next(fd, buf, ARRAY_SIZE(buf), ' '); |
966a082f RL |
118 | if(found != 1) |
119 | break; | |
120 | ||
121 | if(!strncmp(buf, "/dev/shm", strlen("/dev/shm"))) | |
122 | goto found; | |
123 | ||
91b165c0 | 124 | found = next(fd, buf, ARRAY_SIZE(buf), '\n'); |
966a082f RL |
125 | if(found != 1) |
126 | break; | |
127 | } | |
128 | ||
129 | err: | |
130 | if(found == 0) | |
131 | printf("nothing mounted on /dev/shm\n"); | |
132 | else if(found < 0) | |
133 | printf("read returned errno %d\n", -found); | |
134 | ||
135 | return; | |
136 | ||
137 | found: | |
91b165c0 | 138 | found = next(fd, buf, ARRAY_SIZE(buf), ' '); |
966a082f RL |
139 | if(found != 1) |
140 | goto err; | |
141 | ||
142 | if(strncmp(buf, "tmpfs", strlen("tmpfs"))){ | |
143 | printf("not tmpfs\n"); | |
144 | return; | |
145 | } | |
146 | ||
147 | printf("OK\n"); | |
148 | default_tmpdir = "/dev/shm"; | |
149 | } | |
150 | ||
0f80bc85 JD |
151 | /* |
152 | * This proc still used in tt-mode | |
153 | * (file: kernel/tt/ptproxy/proxy.c, proc: start_debugger). | |
154 | * So it isn't 'static' yet. | |
155 | */ | |
156 | int make_tempfile(const char *template, char **out_tempname, int do_unlink) | |
157 | { | |
87276f72 | 158 | char *tempname; |
0f80bc85 JD |
159 | int fd; |
160 | ||
966a082f | 161 | which_tmpdir(); |
87276f72 PBG |
162 | tempname = malloc(MAXPATHLEN); |
163 | ||
0f80bc85 | 164 | find_tempdir(); |
87276f72 | 165 | if (template[0] != '/') |
0f80bc85 JD |
166 | strcpy(tempname, tempdir); |
167 | else | |
87276f72 | 168 | tempname[0] = '\0'; |
0f80bc85 JD |
169 | strcat(tempname, template); |
170 | fd = mkstemp(tempname); | |
171 | if(fd < 0){ | |
172 | fprintf(stderr, "open - cannot create %s: %s\n", tempname, | |
173 | strerror(errno)); | |
87276f72 | 174 | goto out; |
0f80bc85 JD |
175 | } |
176 | if(do_unlink && (unlink(tempname) < 0)){ | |
177 | perror("unlink"); | |
87276f72 | 178 | goto out; |
0f80bc85 JD |
179 | } |
180 | if(out_tempname){ | |
87276f72 PBG |
181 | *out_tempname = tempname; |
182 | } else { | |
183 | free(tempname); | |
0f80bc85 JD |
184 | } |
185 | return(fd); | |
87276f72 PBG |
186 | out: |
187 | free(tempname); | |
188 | return -1; | |
0f80bc85 JD |
189 | } |
190 | ||
191 | #define TEMPNAME_TEMPLATE "vm_file-XXXXXX" | |
192 | ||
193 | /* | |
194 | * This proc is used in start_up.c | |
195 | * So it isn't 'static'. | |
196 | */ | |
ae173816 | 197 | int create_tmp_file(unsigned long long len) |
0f80bc85 JD |
198 | { |
199 | int fd, err; | |
200 | char zero; | |
201 | ||
202 | fd = make_tempfile(TEMPNAME_TEMPLATE, NULL, 1); | |
203 | if(fd < 0) { | |
204 | exit(1); | |
205 | } | |
206 | ||
207 | err = fchmod(fd, 0777); | |
208 | if(err < 0){ | |
209 | perror("os_mode_fd"); | |
210 | exit(1); | |
211 | } | |
212 | ||
190f4939 JD |
213 | /* Seek to len - 1 because writing a character there will |
214 | * increase the file size by one byte, to the desired length. | |
215 | */ | |
216 | if (lseek64(fd, len - 1, SEEK_SET) < 0) { | |
217 | perror("os_seek_file"); | |
0f80bc85 JD |
218 | exit(1); |
219 | } | |
220 | ||
221 | zero = 0; | |
222 | ||
223 | err = os_write_file(fd, &zero, 1); | |
224 | if(err != 1){ | |
225 | errno = -err; | |
226 | perror("os_write_file"); | |
227 | exit(1); | |
228 | } | |
229 | ||
230 | return(fd); | |
231 | } | |
232 | ||
ae173816 | 233 | int create_mem_file(unsigned long long len) |
0f80bc85 JD |
234 | { |
235 | int err, fd; | |
236 | ||
02dea087 | 237 | fd = create_tmp_file(len); |
0f80bc85 JD |
238 | |
239 | err = os_set_exec_close(fd, 1); | |
240 | if(err < 0){ | |
241 | errno = -err; | |
242 | perror("exec_close"); | |
243 | } | |
244 | return(fd); | |
245 | } | |
966a082f RL |
246 | |
247 | ||
248 | void check_tmpexec(void) | |
249 | { | |
250 | void *addr; | |
251 | int err, fd = create_tmp_file(UM_KERN_PAGE_SIZE); | |
252 | ||
253 | addr = mmap(NULL, UM_KERN_PAGE_SIZE, | |
254 | PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE, fd, 0); | |
255 | printf("Checking PROT_EXEC mmap in %s...",tempdir); | |
256 | fflush(stdout); | |
257 | if(addr == MAP_FAILED){ | |
258 | err = errno; | |
259 | perror("failed"); | |
260 | if(err == EPERM) | |
261 | printf("%s must be not mounted noexec\n",tempdir); | |
262 | exit(1); | |
263 | } | |
264 | printf("OK\n"); | |
265 | munmap(addr, UM_KERN_PAGE_SIZE); | |
266 | ||
267 | close(fd); | |
268 | } |