1 | // SPDX-License-Identifier: GPL-2.0 |
2 | #include <linux/kernel.h> |
3 | #include <linux/fs.h> |
4 | #include <linux/minix_fs.h> |
5 | #include <linux/ext2_fs.h> |
6 | #include <linux/romfs_fs.h> |
7 | #include <uapi/linux/cramfs_fs.h> |
8 | #include <linux/initrd.h> |
9 | #include <linux/string.h> |
10 | #include <linux/slab.h> |
11 | |
12 | #include "do_mounts.h" |
13 | #include "../fs/squashfs/squashfs_fs.h" |
14 | |
15 | #include <linux/decompress/generic.h> |
16 | |
17 | static struct file *in_file, *out_file; |
18 | static loff_t in_pos, out_pos; |
19 | |
20 | static int __init prompt_ramdisk(char *str) |
21 | { |
22 | pr_warn("ignoring the deprecated prompt_ramdisk= option\n" ); |
23 | return 1; |
24 | } |
25 | __setup("prompt_ramdisk=" , prompt_ramdisk); |
26 | |
27 | int __initdata rd_image_start; /* starting block # of image */ |
28 | |
29 | static int __init ramdisk_start_setup(char *str) |
30 | { |
31 | rd_image_start = simple_strtol(str,NULL,0); |
32 | return 1; |
33 | } |
34 | __setup("ramdisk_start=" , ramdisk_start_setup); |
35 | |
36 | static int __init crd_load(decompress_fn deco); |
37 | |
38 | /* |
39 | * This routine tries to find a RAM disk image to load, and returns the |
40 | * number of blocks to read for a non-compressed image, 0 if the image |
41 | * is a compressed image, and -1 if an image with the right magic |
42 | * numbers could not be found. |
43 | * |
44 | * We currently check for the following magic numbers: |
45 | * minix |
46 | * ext2 |
47 | * romfs |
48 | * cramfs |
49 | * squashfs |
50 | * gzip |
51 | * bzip2 |
52 | * lzma |
53 | * xz |
54 | * lzo |
55 | * lz4 |
56 | */ |
57 | static int __init |
58 | identify_ramdisk_image(struct file *file, loff_t pos, |
59 | decompress_fn *decompressor) |
60 | { |
61 | const int size = 512; |
62 | struct minix_super_block *minixsb; |
63 | struct romfs_super_block *romfsb; |
64 | struct cramfs_super *cramfsb; |
65 | struct squashfs_super_block *squashfsb; |
66 | int nblocks = -1; |
67 | unsigned char *buf; |
68 | const char *compress_name; |
69 | unsigned long n; |
70 | int start_block = rd_image_start; |
71 | |
72 | buf = kmalloc(size, GFP_KERNEL); |
73 | if (!buf) |
74 | return -ENOMEM; |
75 | |
76 | minixsb = (struct minix_super_block *) buf; |
77 | romfsb = (struct romfs_super_block *) buf; |
78 | cramfsb = (struct cramfs_super *) buf; |
79 | squashfsb = (struct squashfs_super_block *) buf; |
80 | memset(buf, 0xe5, size); |
81 | |
82 | /* |
83 | * Read block 0 to test for compressed kernel |
84 | */ |
85 | pos = start_block * BLOCK_SIZE; |
86 | kernel_read(file, buf, size, &pos); |
87 | |
88 | *decompressor = decompress_method(inbuf: buf, len: size, name: &compress_name); |
89 | if (compress_name) { |
90 | printk(KERN_NOTICE "RAMDISK: %s image found at block %d\n" , |
91 | compress_name, start_block); |
92 | if (!*decompressor) |
93 | printk(KERN_EMERG |
94 | "RAMDISK: %s decompressor not configured!\n" , |
95 | compress_name); |
96 | nblocks = 0; |
97 | goto done; |
98 | } |
99 | |
100 | /* romfs is at block zero too */ |
101 | if (romfsb->word0 == ROMSB_WORD0 && |
102 | romfsb->word1 == ROMSB_WORD1) { |
103 | printk(KERN_NOTICE |
104 | "RAMDISK: romfs filesystem found at block %d\n" , |
105 | start_block); |
106 | nblocks = (ntohl(romfsb->size)+BLOCK_SIZE-1)>>BLOCK_SIZE_BITS; |
107 | goto done; |
108 | } |
109 | |
110 | if (cramfsb->magic == CRAMFS_MAGIC) { |
111 | printk(KERN_NOTICE |
112 | "RAMDISK: cramfs filesystem found at block %d\n" , |
113 | start_block); |
114 | nblocks = (cramfsb->size + BLOCK_SIZE - 1) >> BLOCK_SIZE_BITS; |
115 | goto done; |
116 | } |
117 | |
118 | /* squashfs is at block zero too */ |
119 | if (le32_to_cpu(squashfsb->s_magic) == SQUASHFS_MAGIC) { |
120 | printk(KERN_NOTICE |
121 | "RAMDISK: squashfs filesystem found at block %d\n" , |
122 | start_block); |
123 | nblocks = (le64_to_cpu(squashfsb->bytes_used) + BLOCK_SIZE - 1) |
124 | >> BLOCK_SIZE_BITS; |
125 | goto done; |
126 | } |
127 | |
128 | /* |
129 | * Read 512 bytes further to check if cramfs is padded |
130 | */ |
131 | pos = start_block * BLOCK_SIZE + 0x200; |
132 | kernel_read(file, buf, size, &pos); |
133 | |
134 | if (cramfsb->magic == CRAMFS_MAGIC) { |
135 | printk(KERN_NOTICE |
136 | "RAMDISK: cramfs filesystem found at block %d\n" , |
137 | start_block); |
138 | nblocks = (cramfsb->size + BLOCK_SIZE - 1) >> BLOCK_SIZE_BITS; |
139 | goto done; |
140 | } |
141 | |
142 | /* |
143 | * Read block 1 to test for minix and ext2 superblock |
144 | */ |
145 | pos = (start_block + 1) * BLOCK_SIZE; |
146 | kernel_read(file, buf, size, &pos); |
147 | |
148 | /* Try minix */ |
149 | if (minixsb->s_magic == MINIX_SUPER_MAGIC || |
150 | minixsb->s_magic == MINIX_SUPER_MAGIC2) { |
151 | printk(KERN_NOTICE |
152 | "RAMDISK: Minix filesystem found at block %d\n" , |
153 | start_block); |
154 | nblocks = minixsb->s_nzones << minixsb->s_log_zone_size; |
155 | goto done; |
156 | } |
157 | |
158 | /* Try ext2 */ |
159 | n = ext2_image_size(ext2_sb: buf); |
160 | if (n) { |
161 | printk(KERN_NOTICE |
162 | "RAMDISK: ext2 filesystem found at block %d\n" , |
163 | start_block); |
164 | nblocks = n; |
165 | goto done; |
166 | } |
167 | |
168 | printk(KERN_NOTICE |
169 | "RAMDISK: Couldn't find valid RAM disk image starting at %d.\n" , |
170 | start_block); |
171 | |
172 | done: |
173 | kfree(objp: buf); |
174 | return nblocks; |
175 | } |
176 | |
177 | static unsigned long nr_blocks(struct file *file) |
178 | { |
179 | struct inode *inode = file->f_mapping->host; |
180 | |
181 | if (!S_ISBLK(inode->i_mode)) |
182 | return 0; |
183 | return i_size_read(inode) >> 10; |
184 | } |
185 | |
186 | int __init rd_load_image(char *from) |
187 | { |
188 | int res = 0; |
189 | unsigned long rd_blocks, devblocks; |
190 | int nblocks, i; |
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_file = filp_open("/dev/ram" , O_RDWR, 0); |
199 | if (IS_ERR(ptr: out_file)) |
200 | goto out; |
201 | |
202 | in_file = filp_open(from, O_RDONLY, 0); |
203 | if (IS_ERR(ptr: in_file)) |
204 | goto noclose_input; |
205 | |
206 | in_pos = rd_image_start * BLOCK_SIZE; |
207 | nblocks = identify_ramdisk_image(file: in_file, pos: in_pos, decompressor: &decompressor); |
208 | if (nblocks < 0) |
209 | goto done; |
210 | |
211 | if (nblocks == 0) { |
212 | if (crd_load(deco: decompressor) == 0) |
213 | goto successful_load; |
214 | goto done; |
215 | } |
216 | |
217 | /* |
218 | * NOTE NOTE: nblocks is not actually blocks but |
219 | * the number of kibibytes of data to load into a ramdisk. |
220 | */ |
221 | rd_blocks = nr_blocks(file: out_file); |
222 | if (nblocks > rd_blocks) { |
223 | printk("RAMDISK: image too big! (%dKiB/%ldKiB)\n" , |
224 | nblocks, rd_blocks); |
225 | goto done; |
226 | } |
227 | |
228 | /* |
229 | * OK, time to copy in the data |
230 | */ |
231 | if (strcmp(from, "/initrd.image" ) == 0) |
232 | devblocks = nblocks; |
233 | else |
234 | devblocks = nr_blocks(file: in_file); |
235 | |
236 | if (devblocks == 0) { |
237 | printk(KERN_ERR "RAMDISK: could not determine device size\n" ); |
238 | goto done; |
239 | } |
240 | |
241 | buf = kmalloc(BLOCK_SIZE, GFP_KERNEL); |
242 | if (!buf) { |
243 | printk(KERN_ERR "RAMDISK: could not allocate buffer\n" ); |
244 | goto done; |
245 | } |
246 | |
247 | printk(KERN_NOTICE "RAMDISK: Loading %dKiB [%ld disk%s] into ram disk... " , |
248 | nblocks, ((nblocks-1)/devblocks)+1, nblocks>devblocks ? "s" : "" ); |
249 | for (i = 0; i < nblocks; i++) { |
250 | if (i && (i % devblocks == 0)) { |
251 | pr_cont("done disk #1.\n" ); |
252 | rotate = 0; |
253 | fput(in_file); |
254 | break; |
255 | } |
256 | kernel_read(in_file, buf, BLOCK_SIZE, &in_pos); |
257 | kernel_write(out_file, buf, BLOCK_SIZE, &out_pos); |
258 | #if !defined(CONFIG_S390) |
259 | if (!(i % 16)) { |
260 | pr_cont("%c\b" , rotator[rotate & 0x3]); |
261 | rotate++; |
262 | } |
263 | #endif |
264 | } |
265 | pr_cont("done.\n" ); |
266 | |
267 | successful_load: |
268 | res = 1; |
269 | done: |
270 | fput(in_file); |
271 | noclose_input: |
272 | fput(out_file); |
273 | out: |
274 | kfree(objp: buf); |
275 | init_unlink(pathname: "/dev/ram" ); |
276 | return res; |
277 | } |
278 | |
279 | int __init rd_load_disk(int n) |
280 | { |
281 | create_dev(name: "/dev/root" , dev: ROOT_DEV); |
282 | create_dev(name: "/dev/ram" , MKDEV(RAMDISK_MAJOR, n)); |
283 | return rd_load_image(from: "/dev/root" ); |
284 | } |
285 | |
286 | static int exit_code; |
287 | static int decompress_error; |
288 | |
289 | static long __init compr_fill(void *buf, unsigned long len) |
290 | { |
291 | long r = kernel_read(in_file, buf, len, &in_pos); |
292 | if (r < 0) |
293 | printk(KERN_ERR "RAMDISK: error while reading compressed data" ); |
294 | else if (r == 0) |
295 | printk(KERN_ERR "RAMDISK: EOF while reading compressed data" ); |
296 | return r; |
297 | } |
298 | |
299 | static long __init compr_flush(void *window, unsigned long outcnt) |
300 | { |
301 | long written = kernel_write(out_file, window, outcnt, &out_pos); |
302 | if (written != outcnt) { |
303 | if (decompress_error == 0) |
304 | printk(KERN_ERR |
305 | "RAMDISK: incomplete write (%ld != %ld)\n" , |
306 | written, outcnt); |
307 | decompress_error = 1; |
308 | return -1; |
309 | } |
310 | return outcnt; |
311 | } |
312 | |
313 | static void __init error(char *x) |
314 | { |
315 | printk(KERN_ERR "%s\n" , x); |
316 | exit_code = 1; |
317 | decompress_error = 1; |
318 | } |
319 | |
320 | static int __init crd_load(decompress_fn deco) |
321 | { |
322 | int result; |
323 | |
324 | if (!deco) { |
325 | pr_emerg("Invalid ramdisk decompression routine. " |
326 | "Select appropriate config option.\n" ); |
327 | panic(fmt: "Could not decompress initial ramdisk image." ); |
328 | } |
329 | |
330 | result = deco(NULL, 0, compr_fill, compr_flush, NULL, NULL, error); |
331 | if (decompress_error) |
332 | result = 1; |
333 | return result; |
334 | } |
335 | |