1 /*
2 * Many of the syscalls used in this file expect some of the arguments
3 * to be __user pointers not __kernel pointers. To limit the sparse
4 * noise, turn off sparse checking for this file.
5 */
6 #ifdef __CHECKER__
7 #undef __CHECKER__
8 #warning "Sparse checking disabled for this file"
9 #endif
10
11 #include <linux/kernel.h>
12 #include <linux/fs.h>
13 #include <linux/minix_fs.h>
14 #include <linux/ext2_fs.h>
15 #include <linux/romfs_fs.h>
16 #include <uapi/linux/cramfs_fs.h>
17 #include <linux/initrd.h>
18 #include <linux/string.h>
19 #include <linux/slab.h>
20
21 #include "do_mounts.h"
22 #include "../fs/squashfs/squashfs_fs.h"
23
24 #include <linux/decompress/generic.h>
25
26
27 int __initdata rd_prompt = 1;/* 1 = prompt for RAM disk, 0 = don't prompt */
28
prompt_ramdisk(char * str)29 static int __init prompt_ramdisk(char *str)
30 {
31 rd_prompt = simple_strtol(str,NULL,0) & 1;
32 return 1;
33 }
34 __setup("prompt_ramdisk=", prompt_ramdisk);
35
36 int __initdata rd_image_start; /* starting block # of image */
37
ramdisk_start_setup(char * str)38 static int __init ramdisk_start_setup(char *str)
39 {
40 rd_image_start = simple_strtol(str,NULL,0);
41 return 1;
42 }
43 __setup("ramdisk_start=", ramdisk_start_setup);
44
45 static int __init crd_load(int in_fd, int out_fd, decompress_fn deco);
46
47 /*
48 * This routine tries to find a RAM disk image to load, and returns the
49 * number of blocks to read for a non-compressed image, 0 if the image
50 * is a compressed image, and -1 if an image with the right magic
51 * numbers could not be found.
52 *
53 * We currently check for the following magic numbers:
54 * minix
55 * ext2
56 * romfs
57 * cramfs
58 * squashfs
59 * gzip
60 * bzip2
61 * lzma
62 * xz
63 * lzo
64 * lz4
65 */
66 static int __init
identify_ramdisk_image(int fd,int start_block,decompress_fn * decompressor)67 identify_ramdisk_image(int fd, int start_block, decompress_fn *decompressor)
68 {
69 const int size = 512;
70 struct minix_super_block *minixsb;
71 struct romfs_super_block *romfsb;
72 struct cramfs_super *cramfsb;
73 struct squashfs_super_block *squashfsb;
74 int nblocks = -1;
75 unsigned char *buf;
76 const char *compress_name;
77 unsigned long n;
78
79 buf = kmalloc(size, GFP_KERNEL);
80 if (!buf)
81 return -ENOMEM;
82
83 minixsb = (struct minix_super_block *) buf;
84 romfsb = (struct romfs_super_block *) buf;
85 cramfsb = (struct cramfs_super *) buf;
86 squashfsb = (struct squashfs_super_block *) buf;
87 memset(buf, 0xe5, size);
88
89 /*
90 * Read block 0 to test for compressed kernel
91 */
92 sys_lseek(fd, start_block * BLOCK_SIZE, 0);
93 sys_read(fd, buf, size);
94
95 *decompressor = decompress_method(buf, size, &compress_name);
96 if (compress_name) {
97 printk(KERN_NOTICE "RAMDISK: %s image found at block %d\n",
98 compress_name, start_block);
99 if (!*decompressor)
100 printk(KERN_EMERG
101 "RAMDISK: %s decompressor not configured!\n",
102 compress_name);
103 nblocks = 0;
104 goto done;
105 }
106
107 /* romfs is at block zero too */
108 if (romfsb->word0 == ROMSB_WORD0 &&
109 romfsb->word1 == ROMSB_WORD1) {
110 printk(KERN_NOTICE
111 "RAMDISK: romfs filesystem found at block %d\n",
112 start_block);
113 nblocks = (ntohl(romfsb->size)+BLOCK_SIZE-1)>>BLOCK_SIZE_BITS;
114 goto done;
115 }
116
117 if (cramfsb->magic == CRAMFS_MAGIC) {
118 printk(KERN_NOTICE
119 "RAMDISK: cramfs filesystem found at block %d\n",
120 start_block);
121 nblocks = (cramfsb->size + BLOCK_SIZE - 1) >> BLOCK_SIZE_BITS;
122 goto done;
123 }
124
125 /* squashfs is at block zero too */
126 if (le32_to_cpu(squashfsb->s_magic) == SQUASHFS_MAGIC) {
127 printk(KERN_NOTICE
128 "RAMDISK: squashfs filesystem found at block %d\n",
129 start_block);
130 nblocks = (le64_to_cpu(squashfsb->bytes_used) + BLOCK_SIZE - 1)
131 >> BLOCK_SIZE_BITS;
132 goto done;
133 }
134
135 /*
136 * Read 512 bytes further to check if cramfs is padded
137 */
138 sys_lseek(fd, start_block * BLOCK_SIZE + 0x200, 0);
139 sys_read(fd, buf, size);
140
141 if (cramfsb->magic == CRAMFS_MAGIC) {
142 printk(KERN_NOTICE
143 "RAMDISK: cramfs filesystem found at block %d\n",
144 start_block);
145 nblocks = (cramfsb->size + BLOCK_SIZE - 1) >> BLOCK_SIZE_BITS;
146 goto done;
147 }
148
149 /*
150 * Read block 1 to test for minix and ext2 superblock
151 */
152 sys_lseek(fd, (start_block+1) * BLOCK_SIZE, 0);
153 sys_read(fd, buf, size);
154
155 /* Try minix */
156 if (minixsb->s_magic == MINIX_SUPER_MAGIC ||
157 minixsb->s_magic == MINIX_SUPER_MAGIC2) {
158 printk(KERN_NOTICE
159 "RAMDISK: Minix filesystem found at block %d\n",
160 start_block);
161 nblocks = minixsb->s_nzones << minixsb->s_log_zone_size;
162 goto done;
163 }
164
165 /* Try ext2 */
166 n = ext2_image_size(buf);
167 if (n) {
168 printk(KERN_NOTICE
169 "RAMDISK: ext2 filesystem found at block %d\n",
170 start_block);
171 nblocks = n;
172 goto done;
173 }
174
175 printk(KERN_NOTICE
176 "RAMDISK: Couldn't find valid RAM disk image starting at %d.\n",
177 start_block);
178
179 done:
180 sys_lseek(fd, start_block * BLOCK_SIZE, 0);
181 kfree(buf);
182 return nblocks;
183 }
184
rd_load_image(char * from)185 int __init rd_load_image(char *from)
186 {
187 int res = 0;
188 int in_fd, out_fd;
189 unsigned long rd_blocks, devblocks;
190 int nblocks, i, disk;
191 char *buf = NULL;
192 unsigned short rotate = 0;
193 decompress_fn decompressor = NULL;
194 #if !defined(CONFIG_S390)
195 char rotator[4] = { '|' , '/' , '-' , '\\' };
196 #endif
197
198 out_fd = sys_open("/dev/ram", O_RDWR, 0);
199 if (out_fd < 0)
200 goto out;
201
202 in_fd = sys_open(from, O_RDONLY, 0);
203 if (in_fd < 0)
204 goto noclose_input;
205
206 nblocks = identify_ramdisk_image(in_fd, rd_image_start, &decompressor);
207 if (nblocks < 0)
208 goto done;
209
210 if (nblocks == 0) {
211 if (crd_load(in_fd, out_fd, decompressor) == 0)
212 goto successful_load;
213 goto done;
214 }
215
216 /*
217 * NOTE NOTE: nblocks is not actually blocks but
218 * the number of kibibytes of data to load into a ramdisk.
219 */
220 if (sys_ioctl(out_fd, BLKGETSIZE, (unsigned long)&rd_blocks) < 0)
221 rd_blocks = 0;
222 else
223 rd_blocks >>= 1;
224
225 if (nblocks > rd_blocks) {
226 printk("RAMDISK: image too big! (%dKiB/%ldKiB)\n",
227 nblocks, rd_blocks);
228 goto done;
229 }
230
231 /*
232 * OK, time to copy in the data
233 */
234 if (sys_ioctl(in_fd, BLKGETSIZE, (unsigned long)&devblocks) < 0)
235 devblocks = 0;
236 else
237 devblocks >>= 1;
238
239 if (strcmp(from, "/initrd.image") == 0)
240 devblocks = nblocks;
241
242 if (devblocks == 0) {
243 printk(KERN_ERR "RAMDISK: could not determine device size\n");
244 goto done;
245 }
246
247 buf = kmalloc(BLOCK_SIZE, GFP_KERNEL);
248 if (!buf) {
249 printk(KERN_ERR "RAMDISK: could not allocate buffer\n");
250 goto done;
251 }
252
253 printk(KERN_NOTICE "RAMDISK: Loading %dKiB [%ld disk%s] into ram disk... ",
254 nblocks, ((nblocks-1)/devblocks)+1, nblocks>devblocks ? "s" : "");
255 for (i = 0, disk = 1; i < nblocks; i++) {
256 if (i && (i % devblocks == 0)) {
257 printk("done disk #%d.\n", disk++);
258 rotate = 0;
259 if (sys_close(in_fd)) {
260 printk("Error closing the disk.\n");
261 goto noclose_input;
262 }
263 change_floppy("disk #%d", disk);
264 in_fd = sys_open(from, O_RDONLY, 0);
265 if (in_fd < 0) {
266 printk("Error opening disk.\n");
267 goto noclose_input;
268 }
269 printk("Loading disk #%d... ", disk);
270 }
271 sys_read(in_fd, buf, BLOCK_SIZE);
272 sys_write(out_fd, buf, BLOCK_SIZE);
273 #if !defined(CONFIG_S390)
274 if (!(i % 16)) {
275 pr_cont("%c\b", rotator[rotate & 0x3]);
276 rotate++;
277 }
278 #endif
279 }
280 printk("done.\n");
281
282 successful_load:
283 res = 1;
284 done:
285 sys_close(in_fd);
286 noclose_input:
287 sys_close(out_fd);
288 out:
289 kfree(buf);
290 sys_unlink("/dev/ram");
291 return res;
292 }
293
rd_load_disk(int n)294 int __init rd_load_disk(int n)
295 {
296 if (rd_prompt)
297 change_floppy("root floppy disk to be loaded into RAM disk");
298 create_dev("/dev/root", ROOT_DEV);
299 create_dev("/dev/ram", MKDEV(RAMDISK_MAJOR, n));
300 return rd_load_image("/dev/root");
301 }
302
303 static int exit_code;
304 static int decompress_error;
305 static int crd_infd, crd_outfd;
306
compr_fill(void * buf,unsigned long len)307 static long __init compr_fill(void *buf, unsigned long len)
308 {
309 long r = sys_read(crd_infd, buf, len);
310 if (r < 0)
311 printk(KERN_ERR "RAMDISK: error while reading compressed data");
312 else if (r == 0)
313 printk(KERN_ERR "RAMDISK: EOF while reading compressed data");
314 return r;
315 }
316
compr_flush(void * window,unsigned long outcnt)317 static long __init compr_flush(void *window, unsigned long outcnt)
318 {
319 long written = sys_write(crd_outfd, window, outcnt);
320 if (written != outcnt) {
321 if (decompress_error == 0)
322 printk(KERN_ERR
323 "RAMDISK: incomplete write (%ld != %ld)\n",
324 written, outcnt);
325 decompress_error = 1;
326 return -1;
327 }
328 return outcnt;
329 }
330
error(char * x)331 static void __init error(char *x)
332 {
333 printk(KERN_ERR "%s\n", x);
334 exit_code = 1;
335 decompress_error = 1;
336 }
337
crd_load(int in_fd,int out_fd,decompress_fn deco)338 static int __init crd_load(int in_fd, int out_fd, decompress_fn deco)
339 {
340 int result;
341 crd_infd = in_fd;
342 crd_outfd = out_fd;
343
344 if (!deco) {
345 pr_emerg("Invalid ramdisk decompression routine. "
346 "Select appropriate config option.\n");
347 panic("Could not decompress initial ramdisk image.");
348 }
349
350 result = deco(NULL, 0, compr_fill, compr_flush, NULL, NULL, error);
351 if (decompress_error)
352 result = 1;
353 return result;
354 }
355