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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * misc.c | |
818a08f8 IC |
3 | * |
4 | * This is a collection of several routines from gzip-1.0.3 | |
1da177e4 LT |
5 | * adapted for Linux. |
6 | * | |
7 | * malloc by Hannu Savolainen 1993 and Matthias Urlichs 1994 | |
8 | * puts by Nick Holloway 1993, better puts by Martin Mares 1995 | |
9 | * High loaded stuff by Hans Lermen & Werner Almesberger, Feb. 1996 | |
10 | */ | |
11 | ||
8fee13a4 | 12 | #include "misc.h" |
820e8fec | 13 | #include "../string.h" |
968de4f0 EB |
14 | |
15 | /* WARNING!! | |
16 | * This code is compiled with -fPIC and it is relocated dynamically | |
17 | * at run time, but no relocation processing is performed. | |
18 | * This means that it is not safe to place pointers in static structures. | |
19 | */ | |
20 | ||
21 | /* | |
22 | * Getting to provable safe in place decompression is hard. | |
27b46d76 | 23 | * Worst case behaviours need to be analyzed. |
968de4f0 EB |
24 | * Background information: |
25 | * | |
26 | * The file layout is: | |
27 | * magic[2] | |
28 | * method[1] | |
29 | * flags[1] | |
30 | * timestamp[4] | |
31 | * extraflags[1] | |
32 | * os[1] | |
33 | * compressed data blocks[N] | |
34 | * crc[4] orig_len[4] | |
35 | * | |
36 | * resulting in 18 bytes of non compressed data overhead. | |
37 | * | |
38 | * Files divided into blocks | |
39 | * 1 bit (last block flag) | |
40 | * 2 bits (block type) | |
41 | * | |
1180e01d IM |
42 | * 1 block occurs every 32K -1 bytes or when there 50% compression |
43 | * has been achieved. The smallest block type encoding is always used. | |
968de4f0 EB |
44 | * |
45 | * stored: | |
46 | * 32 bits length in bytes. | |
47 | * | |
48 | * fixed: | |
49 | * magic fixed tree. | |
50 | * symbols. | |
51 | * | |
52 | * dynamic: | |
53 | * dynamic tree encoding. | |
54 | * symbols. | |
55 | * | |
56 | * | |
57 | * The buffer for decompression in place is the length of the | |
58 | * uncompressed data, plus a small amount extra to keep the algorithm safe. | |
59 | * The compressed data is placed at the end of the buffer. The output | |
60 | * pointer is placed at the start of the buffer and the input pointer | |
61 | * is placed where the compressed data starts. Problems will occur | |
62 | * when the output pointer overruns the input pointer. | |
63 | * | |
64 | * The output pointer can only overrun the input pointer if the input | |
65 | * pointer is moving faster than the output pointer. A condition only | |
66 | * triggered by data whose compressed form is larger than the uncompressed | |
67 | * form. | |
68 | * | |
69 | * The worst case at the block level is a growth of the compressed data | |
70 | * of 5 bytes per 32767 bytes. | |
71 | * | |
72 | * The worst case internal to a compressed block is very hard to figure. | |
73 | * The worst case can at least be boundined by having one bit that represents | |
74 | * 32764 bytes and then all of the rest of the bytes representing the very | |
75 | * very last byte. | |
76 | * | |
77 | * All of which is enough to compute an amount of extra data that is required | |
78 | * to be safe. To avoid problems at the block level allocating 5 extra bytes | |
1180e01d IM |
79 | * per 32767 bytes of data is sufficient. To avoind problems internal to a |
80 | * block adding an extra 32767 bytes (the worst case uncompressed block size) | |
81 | * is sufficient, to ensure that in the worst case the decompressed data for | |
968de4f0 EB |
82 | * block will stop the byte before the compressed data for a block begins. |
83 | * To avoid problems with the compressed data's meta information an extra 18 | |
84 | * bytes are needed. Leading to the formula: | |
85 | * | |
86 | * extra_bytes = (uncompressed_size >> 12) + 32768 + 18 + decompressor_size. | |
87 | * | |
88 | * Adding 8 bytes per 32K is a bit excessive but much easier to calculate. | |
89 | * Adding 32768 instead of 32767 just makes for round numbers. | |
90 | * Adding the decompressor_size is necessary as it musht live after all | |
91 | * of the data as well. Last I measured the decompressor is about 14K. | |
27b46d76 | 92 | * 10K of actual data and 4K of bss. |
968de4f0 EB |
93 | * |
94 | */ | |
1da177e4 LT |
95 | |
96 | /* | |
97 | * gzip declarations | |
98 | */ | |
1180e01d | 99 | #define STATIC static |
1da177e4 | 100 | |
1da177e4 | 101 | #undef memcpy |
04999550 VG |
102 | |
103 | /* | |
104 | * Use a normal definition of memset() from string.c. There are already | |
105 | * included header files which expect a definition of memset() and by | |
106 | * the time we define memset macro, it is too late. | |
107 | */ | |
108 | #undef memset | |
1180e01d | 109 | #define memzero(s, n) memset((s), 0, (n)) |
1da177e4 | 110 | |
1da177e4 | 111 | |
1da177e4 | 112 | static void error(char *m); |
fd77c7ca | 113 | |
1da177e4 LT |
114 | /* |
115 | * This is set up by the setup-routine at boot-time | |
116 | */ | |
8fee13a4 | 117 | struct boot_params *real_mode; /* Pointer to real-mode data */ |
1da177e4 | 118 | |
82fa9637 KC |
119 | memptr free_mem_ptr; |
120 | memptr free_mem_end_ptr; | |
1da177e4 | 121 | |
03056c88 | 122 | static char *vidmem; |
1da177e4 LT |
123 | static int vidport; |
124 | static int lines, cols; | |
125 | ||
ae03c499 AK |
126 | #ifdef CONFIG_KERNEL_GZIP |
127 | #include "../../../../lib/decompress_inflate.c" | |
128 | #endif | |
129 | ||
130 | #ifdef CONFIG_KERNEL_BZIP2 | |
131 | #include "../../../../lib/decompress_bunzip2.c" | |
132 | #endif | |
133 | ||
134 | #ifdef CONFIG_KERNEL_LZMA | |
135 | #include "../../../../lib/decompress_unlzma.c" | |
136 | #endif | |
1da177e4 | 137 | |
30314804 LC |
138 | #ifdef CONFIG_KERNEL_XZ |
139 | #include "../../../../lib/decompress_unxz.c" | |
140 | #endif | |
141 | ||
13510997 AT |
142 | #ifdef CONFIG_KERNEL_LZO |
143 | #include "../../../../lib/decompress_unlzo.c" | |
144 | #endif | |
145 | ||
f9b493ac KL |
146 | #ifdef CONFIG_KERNEL_LZ4 |
147 | #include "../../../../lib/decompress_unlz4.c" | |
148 | #endif | |
149 | ||
1da177e4 LT |
150 | static void scroll(void) |
151 | { | |
152 | int i; | |
153 | ||
fd77c7ca PC |
154 | memcpy(vidmem, vidmem + cols * 2, (lines - 1) * cols * 2); |
155 | for (i = (lines - 1) * cols * 2; i < lines * cols * 2; i += 2) | |
1da177e4 LT |
156 | vidmem[i] = ' '; |
157 | } | |
158 | ||
8fee13a4 YL |
159 | #define XMTRDY 0x20 |
160 | ||
161 | #define TXR 0 /* Transmit register (WRITE) */ | |
162 | #define LSR 5 /* Line Status */ | |
163 | static void serial_putchar(int ch) | |
164 | { | |
165 | unsigned timeout = 0xffff; | |
166 | ||
167 | while ((inb(early_serial_base + LSR) & XMTRDY) == 0 && --timeout) | |
168 | cpu_relax(); | |
169 | ||
170 | outb(ch, early_serial_base + TXR); | |
171 | } | |
172 | ||
7aac3015 | 173 | void __putstr(const char *s) |
1da177e4 | 174 | { |
fd77c7ca | 175 | int x, y, pos; |
1da177e4 LT |
176 | char c; |
177 | ||
8fee13a4 YL |
178 | if (early_serial_base) { |
179 | const char *str = s; | |
180 | while (*str) { | |
181 | if (*str == '\n') | |
182 | serial_putchar('\r'); | |
183 | serial_putchar(*str++); | |
184 | } | |
185 | } | |
6bcb13b3 | 186 | |
23968f71 KH |
187 | if (real_mode->screen_info.orig_video_mode == 0 && |
188 | lines == 0 && cols == 0) | |
a24e7851 RR |
189 | return; |
190 | ||
23968f71 KH |
191 | x = real_mode->screen_info.orig_x; |
192 | y = real_mode->screen_info.orig_y; | |
1da177e4 | 193 | |
fd77c7ca PC |
194 | while ((c = *s++) != '\0') { |
195 | if (c == '\n') { | |
1da177e4 | 196 | x = 0; |
fd77c7ca | 197 | if (++y >= lines) { |
1da177e4 LT |
198 | scroll(); |
199 | y--; | |
200 | } | |
201 | } else { | |
020878ac | 202 | vidmem[(x + cols * y) * 2] = c; |
fd77c7ca | 203 | if (++x >= cols) { |
1da177e4 | 204 | x = 0; |
fd77c7ca | 205 | if (++y >= lines) { |
1da177e4 LT |
206 | scroll(); |
207 | y--; | |
208 | } | |
209 | } | |
210 | } | |
211 | } | |
212 | ||
23968f71 KH |
213 | real_mode->screen_info.orig_x = x; |
214 | real_mode->screen_info.orig_y = y; | |
1da177e4 LT |
215 | |
216 | pos = (x + cols * y) * 2; /* Update cursor position */ | |
b02aae9c RH |
217 | outb(14, vidport); |
218 | outb(0xff & (pos >> 9), vidport+1); | |
219 | outb(15, vidport); | |
220 | outb(0xff & (pos >> 1), vidport+1); | |
1da177e4 LT |
221 | } |
222 | ||
1da177e4 LT |
223 | static void error(char *x) |
224 | { | |
cb454fe1 JM |
225 | error_putstr("\n\n"); |
226 | error_putstr(x); | |
227 | error_putstr("\n\n -- System halted"); | |
1da177e4 | 228 | |
ff3cf856 IM |
229 | while (1) |
230 | asm("hlt"); | |
1da177e4 LT |
231 | } |
232 | ||
a0215061 KC |
233 | #if CONFIG_X86_NEED_RELOCS |
234 | static void handle_relocations(void *output, unsigned long output_len) | |
235 | { | |
236 | int *reloc; | |
237 | unsigned long delta, map, ptr; | |
238 | unsigned long min_addr = (unsigned long)output; | |
239 | unsigned long max_addr = min_addr + output_len; | |
240 | ||
241 | /* | |
242 | * Calculate the delta between where vmlinux was linked to load | |
243 | * and where it was actually loaded. | |
244 | */ | |
245 | delta = min_addr - LOAD_PHYSICAL_ADDR; | |
246 | if (!delta) { | |
247 | debug_putstr("No relocation needed... "); | |
248 | return; | |
249 | } | |
250 | debug_putstr("Performing relocations... "); | |
251 | ||
252 | /* | |
253 | * The kernel contains a table of relocation addresses. Those | |
254 | * addresses have the final load address of the kernel in virtual | |
255 | * memory. We are currently working in the self map. So we need to | |
256 | * create an adjustment for kernel memory addresses to the self map. | |
257 | * This will involve subtracting out the base address of the kernel. | |
258 | */ | |
259 | map = delta - __START_KERNEL_map; | |
260 | ||
261 | /* | |
262 | * Process relocations: 32 bit relocations first then 64 bit after. | |
6d24c5f7 | 263 | * Three sets of binary relocations are added to the end of the kernel |
a0215061 KC |
264 | * before compression. Each relocation table entry is the kernel |
265 | * address of the location which needs to be updated stored as a | |
266 | * 32-bit value which is sign extended to 64 bits. | |
267 | * | |
268 | * Format is: | |
269 | * | |
270 | * kernel bits... | |
271 | * 0 - zero terminator for 64 bit relocations | |
272 | * 64 bit relocation repeated | |
6d24c5f7 JB |
273 | * 0 - zero terminator for inverse 32 bit relocations |
274 | * 32 bit inverse relocation repeated | |
a0215061 KC |
275 | * 0 - zero terminator for 32 bit relocations |
276 | * 32 bit relocation repeated | |
277 | * | |
278 | * So we work backwards from the end of the decompressed image. | |
279 | */ | |
280 | for (reloc = output + output_len - sizeof(*reloc); *reloc; reloc--) { | |
281 | int extended = *reloc; | |
282 | extended += map; | |
283 | ||
284 | ptr = (unsigned long)extended; | |
285 | if (ptr < min_addr || ptr > max_addr) | |
286 | error("32-bit relocation outside of kernel!\n"); | |
287 | ||
288 | *(uint32_t *)ptr += delta; | |
289 | } | |
290 | #ifdef CONFIG_X86_64 | |
6d24c5f7 JB |
291 | while (*--reloc) { |
292 | long extended = *reloc; | |
293 | extended += map; | |
294 | ||
295 | ptr = (unsigned long)extended; | |
296 | if (ptr < min_addr || ptr > max_addr) | |
297 | error("inverse 32-bit relocation outside of kernel!\n"); | |
298 | ||
299 | *(int32_t *)ptr -= delta; | |
300 | } | |
a0215061 KC |
301 | for (reloc--; *reloc; reloc--) { |
302 | long extended = *reloc; | |
303 | extended += map; | |
304 | ||
305 | ptr = (unsigned long)extended; | |
306 | if (ptr < min_addr || ptr > max_addr) | |
307 | error("64-bit relocation outside of kernel!\n"); | |
308 | ||
309 | *(uint64_t *)ptr += delta; | |
310 | } | |
311 | #endif | |
312 | } | |
313 | #else | |
314 | static inline void handle_relocations(void *output, unsigned long output_len) | |
315 | { } | |
316 | #endif | |
317 | ||
099e1377 IC |
318 | static void parse_elf(void *output) |
319 | { | |
320 | #ifdef CONFIG_X86_64 | |
321 | Elf64_Ehdr ehdr; | |
322 | Elf64_Phdr *phdrs, *phdr; | |
323 | #else | |
324 | Elf32_Ehdr ehdr; | |
325 | Elf32_Phdr *phdrs, *phdr; | |
326 | #endif | |
327 | void *dest; | |
328 | int i; | |
329 | ||
330 | memcpy(&ehdr, output, sizeof(ehdr)); | |
fd77c7ca | 331 | if (ehdr.e_ident[EI_MAG0] != ELFMAG0 || |
099e1377 IC |
332 | ehdr.e_ident[EI_MAG1] != ELFMAG1 || |
333 | ehdr.e_ident[EI_MAG2] != ELFMAG2 || | |
fd77c7ca | 334 | ehdr.e_ident[EI_MAG3] != ELFMAG3) { |
099e1377 IC |
335 | error("Kernel is not a valid ELF file"); |
336 | return; | |
337 | } | |
338 | ||
e605a425 | 339 | debug_putstr("Parsing ELF... "); |
099e1377 IC |
340 | |
341 | phdrs = malloc(sizeof(*phdrs) * ehdr.e_phnum); | |
342 | if (!phdrs) | |
343 | error("Failed to allocate space for phdrs"); | |
344 | ||
345 | memcpy(phdrs, output + ehdr.e_phoff, sizeof(*phdrs) * ehdr.e_phnum); | |
346 | ||
fd77c7ca | 347 | for (i = 0; i < ehdr.e_phnum; i++) { |
099e1377 IC |
348 | phdr = &phdrs[i]; |
349 | ||
350 | switch (phdr->p_type) { | |
351 | case PT_LOAD: | |
352 | #ifdef CONFIG_RELOCATABLE | |
353 | dest = output; | |
354 | dest += (phdr->p_paddr - LOAD_PHYSICAL_ADDR); | |
355 | #else | |
fd77c7ca | 356 | dest = (void *)(phdr->p_paddr); |
099e1377 IC |
357 | #endif |
358 | memcpy(dest, | |
359 | output + phdr->p_offset, | |
360 | phdr->p_filesz); | |
361 | break; | |
362 | default: /* Ignore other PT_* */ break; | |
363 | } | |
364 | } | |
5067cf53 JJ |
365 | |
366 | free(phdrs); | |
099e1377 IC |
367 | } |
368 | ||
2605fc21 | 369 | asmlinkage __visible void *decompress_kernel(void *rmode, memptr heap, |
1180e01d IM |
370 | unsigned char *input_data, |
371 | unsigned long input_len, | |
a0215061 | 372 | unsigned char *output, |
e6023367 JM |
373 | unsigned long output_len, |
374 | unsigned long run_size) | |
1da177e4 | 375 | { |
f285f4a2 KC |
376 | unsigned char *output_orig = output; |
377 | ||
1da177e4 LT |
378 | real_mode = rmode; |
379 | ||
78cac48c BP |
380 | /* Clear it for solely in-kernel use */ |
381 | real_mode->hdr.loadflags &= ~KASLR_FLAG; | |
382 | ||
5dcd14ec PA |
383 | sanitize_boot_params(real_mode); |
384 | ||
23968f71 | 385 | if (real_mode->screen_info.orig_video_mode == 7) { |
1da177e4 LT |
386 | vidmem = (char *) 0xb0000; |
387 | vidport = 0x3b4; | |
388 | } else { | |
389 | vidmem = (char *) 0xb8000; | |
390 | vidport = 0x3d4; | |
391 | } | |
392 | ||
23968f71 KH |
393 | lines = real_mode->screen_info.orig_video_lines; |
394 | cols = real_mode->screen_info.orig_video_cols; | |
1da177e4 | 395 | |
8fee13a4 | 396 | console_init(); |
e605a425 | 397 | debug_putstr("early console in decompress_kernel\n"); |
8fee13a4 | 398 | |
4c83d653 | 399 | free_mem_ptr = heap; /* Heap */ |
7c539764 | 400 | free_mem_end_ptr = heap + BOOT_HEAP_SIZE; |
968de4f0 | 401 | |
e6023367 JM |
402 | /* |
403 | * The memory hole needed for the kernel is the larger of either | |
404 | * the entire decompressed kernel plus relocation table, or the | |
405 | * entire decompressed kernel plus .bss and .brk sections. | |
406 | */ | |
78cac48c | 407 | output = choose_kernel_location(real_mode, input_data, input_len, output, |
e6023367 JM |
408 | output_len > run_size ? output_len |
409 | : run_size); | |
8ab3820f KC |
410 | |
411 | /* Validate memory location choices. */ | |
7ed42a28 PA |
412 | if ((unsigned long)output & (MIN_KERNEL_ALIGN - 1)) |
413 | error("Destination address inappropriately aligned"); | |
778cb929 | 414 | #ifdef CONFIG_X86_64 |
7ed42a28 | 415 | if (heap > 0x3fffffffffffUL) |
778cb929 IC |
416 | error("Destination address too large"); |
417 | #else | |
147dd561 | 418 | if (heap > ((-__PAGE_OFFSET-(128<<20)-1) & 0x7fffffff)) |
968de4f0 | 419 | error("Destination address too large"); |
7ed42a28 | 420 | #endif |
968de4f0 | 421 | #ifndef CONFIG_RELOCATABLE |
7ed42a28 | 422 | if ((unsigned long)output != LOAD_PHYSICAL_ADDR) |
968de4f0 EB |
423 | error("Wrong destination address"); |
424 | #endif | |
1da177e4 | 425 | |
e605a425 | 426 | debug_putstr("\nDecompressing Linux... "); |
ae03c499 | 427 | decompress(input_data, input_len, NULL, NULL, output, NULL, error); |
099e1377 | 428 | parse_elf(output); |
f285f4a2 KC |
429 | /* |
430 | * 32-bit always performs relocations. 64-bit relocations are only | |
431 | * needed if kASLR has chosen a different load address. | |
432 | */ | |
433 | if (!IS_ENABLED(CONFIG_X86_64) || output != output_orig) | |
434 | handle_relocations(output, output_len); | |
e605a425 | 435 | debug_putstr("done.\nBooting the kernel.\n"); |
8ab3820f | 436 | return output; |
1da177e4 | 437 | } |