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v6.2
  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * misc.c
  4 *
  5 * This is a collection of several routines used to extract the kernel
  6 * which includes KASLR relocation, decompression, ELF parsing, and
  7 * relocation processing. Additionally included are the screen and serial
  8 * output functions and related debugging support functions.
  9 *
 10 * malloc by Hannu Savolainen 1993 and Matthias Urlichs 1994
 11 * puts by Nick Holloway 1993, better puts by Martin Mares 1995
 12 * High loaded stuff by Hans Lermen & Werner Almesberger, Feb. 1996
 13 */
 14
 15#include "misc.h"
 16#include "error.h"
 17#include "pgtable.h"
 18#include "../string.h"
 19#include "../voffset.h"
 20#include <asm/bootparam_utils.h>
 21
 22/*
 23 * WARNING!!
 24 * This code is compiled with -fPIC and it is relocated dynamically at
 25 * run time, but no relocation processing is performed. This means that
 26 * it is not safe to place pointers in static structures.
 27 */
 28
 29/* Macros used by the included decompressor code below. */
 30#define STATIC		static
 31/* Define an externally visible malloc()/free(). */
 32#define MALLOC_VISIBLE
 33#include <linux/decompress/mm.h>
 34
 35/*
 36 * Provide definitions of memzero and memmove as some of the decompressors will
 37 * try to define their own functions if these are not defined as macros.
 
 38 */
 
 
 39#define memzero(s, n)	memset((s), 0, (n))
 40#ifndef memmove
 41#define memmove		memmove
 
 42/* Functions used by the included decompressor code below. */
 43void *memmove(void *dest, const void *src, size_t n);
 44#endif
 45
 46/*
 47 * This is set up by the setup-routine at boot-time
 48 */
 49struct boot_params *boot_params;
 50
 51struct port_io_ops pio_ops;
 52
 53memptr free_mem_ptr;
 54memptr free_mem_end_ptr;
 55
 56static char *vidmem;
 57static int vidport;
 58
 59/* These might be accessed before .bss is cleared, so use .data instead. */
 60static int lines __section(".data");
 61static int cols __section(".data");
 62
 63#ifdef CONFIG_KERNEL_GZIP
 64#include "../../../../lib/decompress_inflate.c"
 65#endif
 66
 67#ifdef CONFIG_KERNEL_BZIP2
 68#include "../../../../lib/decompress_bunzip2.c"
 69#endif
 70
 71#ifdef CONFIG_KERNEL_LZMA
 72#include "../../../../lib/decompress_unlzma.c"
 73#endif
 74
 75#ifdef CONFIG_KERNEL_XZ
 76#include "../../../../lib/decompress_unxz.c"
 77#endif
 78
 79#ifdef CONFIG_KERNEL_LZO
 80#include "../../../../lib/decompress_unlzo.c"
 81#endif
 82
 83#ifdef CONFIG_KERNEL_LZ4
 84#include "../../../../lib/decompress_unlz4.c"
 85#endif
 86
 87#ifdef CONFIG_KERNEL_ZSTD
 88#include "../../../../lib/decompress_unzstd.c"
 89#endif
 90/*
 91 * NOTE: When adding a new decompressor, please update the analysis in
 92 * ../header.S.
 93 */
 94
 95static void scroll(void)
 96{
 97	int i;
 98
 99	memmove(vidmem, vidmem + cols * 2, (lines - 1) * cols * 2);
100	for (i = (lines - 1) * cols * 2; i < lines * cols * 2; i += 2)
101		vidmem[i] = ' ';
102}
103
104#define XMTRDY          0x20
105
106#define TXR             0       /*  Transmit register (WRITE) */
107#define LSR             5       /*  Line Status               */
108static void serial_putchar(int ch)
109{
110	unsigned timeout = 0xffff;
111
112	while ((inb(early_serial_base + LSR) & XMTRDY) == 0 && --timeout)
113		cpu_relax();
114
115	outb(ch, early_serial_base + TXR);
116}
117
118void __putstr(const char *s)
119{
120	int x, y, pos;
121	char c;
122
123	if (early_serial_base) {
124		const char *str = s;
125		while (*str) {
126			if (*str == '\n')
127				serial_putchar('\r');
128			serial_putchar(*str++);
129		}
130	}
131
132	if (lines == 0 || cols == 0)
133		return;
134
135	x = boot_params->screen_info.orig_x;
136	y = boot_params->screen_info.orig_y;
137
138	while ((c = *s++) != '\0') {
139		if (c == '\n') {
140			x = 0;
141			if (++y >= lines) {
142				scroll();
143				y--;
144			}
145		} else {
146			vidmem[(x + cols * y) * 2] = c;
147			if (++x >= cols) {
148				x = 0;
149				if (++y >= lines) {
150					scroll();
151					y--;
152				}
153			}
154		}
155	}
156
157	boot_params->screen_info.orig_x = x;
158	boot_params->screen_info.orig_y = y;
159
160	pos = (x + cols * y) * 2;	/* Update cursor position */
161	outb(14, vidport);
162	outb(0xff & (pos >> 9), vidport+1);
163	outb(15, vidport);
164	outb(0xff & (pos >> 1), vidport+1);
165}
166
167void __puthex(unsigned long value)
168{
169	char alpha[2] = "0";
170	int bits;
171
172	for (bits = sizeof(value) * 8 - 4; bits >= 0; bits -= 4) {
173		unsigned long digit = (value >> bits) & 0xf;
174
175		if (digit < 0xA)
176			alpha[0] = '0' + digit;
177		else
178			alpha[0] = 'a' + (digit - 0xA);
179
180		__putstr(alpha);
181	}
182}
183
184#ifdef CONFIG_X86_NEED_RELOCS
185static void handle_relocations(void *output, unsigned long output_len,
186			       unsigned long virt_addr)
187{
188	int *reloc;
189	unsigned long delta, map, ptr;
190	unsigned long min_addr = (unsigned long)output;
191	unsigned long max_addr = min_addr + (VO___bss_start - VO__text);
192
193	/*
194	 * Calculate the delta between where vmlinux was linked to load
195	 * and where it was actually loaded.
196	 */
197	delta = min_addr - LOAD_PHYSICAL_ADDR;
198
199	/*
200	 * The kernel contains a table of relocation addresses. Those
201	 * addresses have the final load address of the kernel in virtual
202	 * memory. We are currently working in the self map. So we need to
203	 * create an adjustment for kernel memory addresses to the self map.
204	 * This will involve subtracting out the base address of the kernel.
205	 */
206	map = delta - __START_KERNEL_map;
207
208	/*
209	 * 32-bit always performs relocations. 64-bit relocations are only
210	 * needed if KASLR has chosen a different starting address offset
211	 * from __START_KERNEL_map.
212	 */
213	if (IS_ENABLED(CONFIG_X86_64))
214		delta = virt_addr - LOAD_PHYSICAL_ADDR;
215
216	if (!delta) {
217		debug_putstr("No relocation needed... ");
218		return;
219	}
220	debug_putstr("Performing relocations... ");
221
222	/*
223	 * Process relocations: 32 bit relocations first then 64 bit after.
224	 * Three sets of binary relocations are added to the end of the kernel
225	 * before compression. Each relocation table entry is the kernel
226	 * address of the location which needs to be updated stored as a
227	 * 32-bit value which is sign extended to 64 bits.
228	 *
229	 * Format is:
230	 *
231	 * kernel bits...
232	 * 0 - zero terminator for 64 bit relocations
233	 * 64 bit relocation repeated
234	 * 0 - zero terminator for inverse 32 bit relocations
235	 * 32 bit inverse relocation repeated
236	 * 0 - zero terminator for 32 bit relocations
237	 * 32 bit relocation repeated
238	 *
239	 * So we work backwards from the end of the decompressed image.
240	 */
241	for (reloc = output + output_len - sizeof(*reloc); *reloc; reloc--) {
242		long extended = *reloc;
243		extended += map;
244
245		ptr = (unsigned long)extended;
246		if (ptr < min_addr || ptr > max_addr)
247			error("32-bit relocation outside of kernel!\n");
248
249		*(uint32_t *)ptr += delta;
250	}
251#ifdef CONFIG_X86_64
252	while (*--reloc) {
253		long extended = *reloc;
254		extended += map;
255
256		ptr = (unsigned long)extended;
257		if (ptr < min_addr || ptr > max_addr)
258			error("inverse 32-bit relocation outside of kernel!\n");
259
260		*(int32_t *)ptr -= delta;
261	}
262	for (reloc--; *reloc; reloc--) {
263		long extended = *reloc;
264		extended += map;
265
266		ptr = (unsigned long)extended;
267		if (ptr < min_addr || ptr > max_addr)
268			error("64-bit relocation outside of kernel!\n");
269
270		*(uint64_t *)ptr += delta;
271	}
272#endif
273}
274#else
275static inline void handle_relocations(void *output, unsigned long output_len,
276				      unsigned long virt_addr)
277{ }
278#endif
279
280static void parse_elf(void *output)
281{
282#ifdef CONFIG_X86_64
283	Elf64_Ehdr ehdr;
284	Elf64_Phdr *phdrs, *phdr;
285#else
286	Elf32_Ehdr ehdr;
287	Elf32_Phdr *phdrs, *phdr;
288#endif
289	void *dest;
290	int i;
291
292	memcpy(&ehdr, output, sizeof(ehdr));
293	if (ehdr.e_ident[EI_MAG0] != ELFMAG0 ||
294	   ehdr.e_ident[EI_MAG1] != ELFMAG1 ||
295	   ehdr.e_ident[EI_MAG2] != ELFMAG2 ||
296	   ehdr.e_ident[EI_MAG3] != ELFMAG3) {
297		error("Kernel is not a valid ELF file");
298		return;
299	}
300
301	debug_putstr("Parsing ELF... ");
302
303	phdrs = malloc(sizeof(*phdrs) * ehdr.e_phnum);
304	if (!phdrs)
305		error("Failed to allocate space for phdrs");
306
307	memcpy(phdrs, output + ehdr.e_phoff, sizeof(*phdrs) * ehdr.e_phnum);
308
309	for (i = 0; i < ehdr.e_phnum; i++) {
310		phdr = &phdrs[i];
311
312		switch (phdr->p_type) {
313		case PT_LOAD:
314#ifdef CONFIG_X86_64
315			if ((phdr->p_align % 0x200000) != 0)
316				error("Alignment of LOAD segment isn't multiple of 2MB");
317#endif
318#ifdef CONFIG_RELOCATABLE
319			dest = output;
320			dest += (phdr->p_paddr - LOAD_PHYSICAL_ADDR);
321#else
322			dest = (void *)(phdr->p_paddr);
323#endif
324			memmove(dest, output + phdr->p_offset, phdr->p_filesz);
325			break;
326		default: /* Ignore other PT_* */ break;
327		}
328	}
329
330	free(phdrs);
331}
332
333/*
334 * The compressed kernel image (ZO), has been moved so that its position
335 * is against the end of the buffer used to hold the uncompressed kernel
336 * image (VO) and the execution environment (.bss, .brk), which makes sure
337 * there is room to do the in-place decompression. (See header.S for the
338 * calculations.)
339 *
340 *                             |-----compressed kernel image------|
341 *                             V                                  V
342 * 0                       extract_offset                      +INIT_SIZE
343 * |-----------|---------------|-------------------------|--------|
344 *             |               |                         |        |
345 *           VO__text      startup_32 of ZO          VO__end    ZO__end
346 *             ^                                         ^
347 *             |-------uncompressed kernel image---------|
348 *
349 */
350asmlinkage __visible void *extract_kernel(void *rmode, memptr heap,
351				  unsigned char *input_data,
352				  unsigned long input_len,
353				  unsigned char *output,
354				  unsigned long output_len)
355{
356	const unsigned long kernel_total_size = VO__end - VO__text;
357	unsigned long virt_addr = LOAD_PHYSICAL_ADDR;
358	unsigned long needed_size;
359
360	/* Retain x86 boot parameters pointer passed from startup_32/64. */
361	boot_params = rmode;
362
363	/* Clear flags intended for solely in-kernel use. */
364	boot_params->hdr.loadflags &= ~KASLR_FLAG;
365
366	sanitize_boot_params(boot_params);
367
368	if (boot_params->screen_info.orig_video_mode == 7) {
369		vidmem = (char *) 0xb0000;
370		vidport = 0x3b4;
371	} else {
372		vidmem = (char *) 0xb8000;
373		vidport = 0x3d4;
374	}
375
376	lines = boot_params->screen_info.orig_video_lines;
377	cols = boot_params->screen_info.orig_video_cols;
378
379	init_default_io_ops();
380
381	/*
382	 * Detect TDX guest environment.
383	 *
384	 * It has to be done before console_init() in order to use
385	 * paravirtualized port I/O operations if needed.
386	 */
387	early_tdx_detect();
388
389	console_init();
390
391	/*
392	 * Save RSDP address for later use. Have this after console_init()
393	 * so that early debugging output from the RSDP parsing code can be
394	 * collected.
395	 */
396	boot_params->acpi_rsdp_addr = get_rsdp_addr();
397
398	debug_putstr("early console in extract_kernel\n");
399
400	free_mem_ptr     = heap;	/* Heap */
401	free_mem_end_ptr = heap + BOOT_HEAP_SIZE;
402
403	/*
404	 * The memory hole needed for the kernel is the larger of either
405	 * the entire decompressed kernel plus relocation table, or the
406	 * entire decompressed kernel plus .bss and .brk sections.
407	 *
408	 * On X86_64, the memory is mapped with PMD pages. Round the
409	 * size up so that the full extent of PMD pages mapped is
410	 * included in the check against the valid memory table
411	 * entries. This ensures the full mapped area is usable RAM
412	 * and doesn't include any reserved areas.
413	 */
414	needed_size = max(output_len, kernel_total_size);
415#ifdef CONFIG_X86_64
416	needed_size = ALIGN(needed_size, MIN_KERNEL_ALIGN);
417#endif
418
419	/* Report initial kernel position details. */
420	debug_putaddr(input_data);
421	debug_putaddr(input_len);
422	debug_putaddr(output);
423	debug_putaddr(output_len);
424	debug_putaddr(kernel_total_size);
425	debug_putaddr(needed_size);
426
427#ifdef CONFIG_X86_64
428	/* Report address of 32-bit trampoline */
429	debug_putaddr(trampoline_32bit);
430#endif
431
 
 
 
 
 
432	choose_random_location((unsigned long)input_data, input_len,
433				(unsigned long *)&output,
434				needed_size,
435				&virt_addr);
436
437	/* Validate memory location choices. */
438	if ((unsigned long)output & (MIN_KERNEL_ALIGN - 1))
439		error("Destination physical address inappropriately aligned");
440	if (virt_addr & (MIN_KERNEL_ALIGN - 1))
441		error("Destination virtual address inappropriately aligned");
442#ifdef CONFIG_X86_64
443	if (heap > 0x3fffffffffffUL)
444		error("Destination address too large");
445	if (virt_addr + max(output_len, kernel_total_size) > KERNEL_IMAGE_SIZE)
446		error("Destination virtual address is beyond the kernel mapping area");
447#else
448	if (heap > ((-__PAGE_OFFSET-(128<<20)-1) & 0x7fffffff))
449		error("Destination address too large");
450#endif
451#ifndef CONFIG_RELOCATABLE
 
 
452	if (virt_addr != LOAD_PHYSICAL_ADDR)
453		error("Destination virtual address changed when not relocatable");
454#endif
455
456	debug_putstr("\nDecompressing Linux... ");
457	__decompress(input_data, input_len, NULL, NULL, output, output_len,
458			NULL, error);
459	parse_elf(output);
460	handle_relocations(output, output_len, virt_addr);
461	debug_putstr("done.\nBooting the kernel.\n");
462
463	/* Disable exception handling before booting the kernel */
464	cleanup_exception_handling();
465
466	return output;
467}
468
469void fortify_panic(const char *name)
470{
471	error("detected buffer overflow");
472}
v4.17
  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * misc.c
  4 *
  5 * This is a collection of several routines used to extract the kernel
  6 * which includes KASLR relocation, decompression, ELF parsing, and
  7 * relocation processing. Additionally included are the screen and serial
  8 * output functions and related debugging support functions.
  9 *
 10 * malloc by Hannu Savolainen 1993 and Matthias Urlichs 1994
 11 * puts by Nick Holloway 1993, better puts by Martin Mares 1995
 12 * High loaded stuff by Hans Lermen & Werner Almesberger, Feb. 1996
 13 */
 14
 15#include "misc.h"
 16#include "error.h"
 17#include "pgtable.h"
 18#include "../string.h"
 19#include "../voffset.h"
 
 20
 21/*
 22 * WARNING!!
 23 * This code is compiled with -fPIC and it is relocated dynamically at
 24 * run time, but no relocation processing is performed. This means that
 25 * it is not safe to place pointers in static structures.
 26 */
 27
 28/* Macros used by the included decompressor code below. */
 29#define STATIC		static
 
 
 
 30
 31/*
 32 * Use normal definitions of mem*() from string.c. There are already
 33 * included header files which expect a definition of memset() and by
 34 * the time we define memset macro, it is too late.
 35 */
 36#undef memcpy
 37#undef memset
 38#define memzero(s, n)	memset((s), 0, (n))
 
 39#define memmove		memmove
 40
 41/* Functions used by the included decompressor code below. */
 42void *memmove(void *dest, const void *src, size_t n);
 
 43
 44/*
 45 * This is set up by the setup-routine at boot-time
 46 */
 47struct boot_params *boot_params;
 48
 
 
 49memptr free_mem_ptr;
 50memptr free_mem_end_ptr;
 51
 52static char *vidmem;
 53static int vidport;
 54static int lines, cols;
 
 
 
 55
 56#ifdef CONFIG_KERNEL_GZIP
 57#include "../../../../lib/decompress_inflate.c"
 58#endif
 59
 60#ifdef CONFIG_KERNEL_BZIP2
 61#include "../../../../lib/decompress_bunzip2.c"
 62#endif
 63
 64#ifdef CONFIG_KERNEL_LZMA
 65#include "../../../../lib/decompress_unlzma.c"
 66#endif
 67
 68#ifdef CONFIG_KERNEL_XZ
 69#include "../../../../lib/decompress_unxz.c"
 70#endif
 71
 72#ifdef CONFIG_KERNEL_LZO
 73#include "../../../../lib/decompress_unlzo.c"
 74#endif
 75
 76#ifdef CONFIG_KERNEL_LZ4
 77#include "../../../../lib/decompress_unlz4.c"
 78#endif
 
 
 
 
 79/*
 80 * NOTE: When adding a new decompressor, please update the analysis in
 81 * ../header.S.
 82 */
 83
 84static void scroll(void)
 85{
 86	int i;
 87
 88	memmove(vidmem, vidmem + cols * 2, (lines - 1) * cols * 2);
 89	for (i = (lines - 1) * cols * 2; i < lines * cols * 2; i += 2)
 90		vidmem[i] = ' ';
 91}
 92
 93#define XMTRDY          0x20
 94
 95#define TXR             0       /*  Transmit register (WRITE) */
 96#define LSR             5       /*  Line Status               */
 97static void serial_putchar(int ch)
 98{
 99	unsigned timeout = 0xffff;
100
101	while ((inb(early_serial_base + LSR) & XMTRDY) == 0 && --timeout)
102		cpu_relax();
103
104	outb(ch, early_serial_base + TXR);
105}
106
107void __putstr(const char *s)
108{
109	int x, y, pos;
110	char c;
111
112	if (early_serial_base) {
113		const char *str = s;
114		while (*str) {
115			if (*str == '\n')
116				serial_putchar('\r');
117			serial_putchar(*str++);
118		}
119	}
120
121	if (lines == 0 || cols == 0)
122		return;
123
124	x = boot_params->screen_info.orig_x;
125	y = boot_params->screen_info.orig_y;
126
127	while ((c = *s++) != '\0') {
128		if (c == '\n') {
129			x = 0;
130			if (++y >= lines) {
131				scroll();
132				y--;
133			}
134		} else {
135			vidmem[(x + cols * y) * 2] = c;
136			if (++x >= cols) {
137				x = 0;
138				if (++y >= lines) {
139					scroll();
140					y--;
141				}
142			}
143		}
144	}
145
146	boot_params->screen_info.orig_x = x;
147	boot_params->screen_info.orig_y = y;
148
149	pos = (x + cols * y) * 2;	/* Update cursor position */
150	outb(14, vidport);
151	outb(0xff & (pos >> 9), vidport+1);
152	outb(15, vidport);
153	outb(0xff & (pos >> 1), vidport+1);
154}
155
156void __puthex(unsigned long value)
157{
158	char alpha[2] = "0";
159	int bits;
160
161	for (bits = sizeof(value) * 8 - 4; bits >= 0; bits -= 4) {
162		unsigned long digit = (value >> bits) & 0xf;
163
164		if (digit < 0xA)
165			alpha[0] = '0' + digit;
166		else
167			alpha[0] = 'a' + (digit - 0xA);
168
169		__putstr(alpha);
170	}
171}
172
173#if CONFIG_X86_NEED_RELOCS
174static void handle_relocations(void *output, unsigned long output_len,
175			       unsigned long virt_addr)
176{
177	int *reloc;
178	unsigned long delta, map, ptr;
179	unsigned long min_addr = (unsigned long)output;
180	unsigned long max_addr = min_addr + (VO___bss_start - VO__text);
181
182	/*
183	 * Calculate the delta between where vmlinux was linked to load
184	 * and where it was actually loaded.
185	 */
186	delta = min_addr - LOAD_PHYSICAL_ADDR;
187
188	/*
189	 * The kernel contains a table of relocation addresses. Those
190	 * addresses have the final load address of the kernel in virtual
191	 * memory. We are currently working in the self map. So we need to
192	 * create an adjustment for kernel memory addresses to the self map.
193	 * This will involve subtracting out the base address of the kernel.
194	 */
195	map = delta - __START_KERNEL_map;
196
197	/*
198	 * 32-bit always performs relocations. 64-bit relocations are only
199	 * needed if KASLR has chosen a different starting address offset
200	 * from __START_KERNEL_map.
201	 */
202	if (IS_ENABLED(CONFIG_X86_64))
203		delta = virt_addr - LOAD_PHYSICAL_ADDR;
204
205	if (!delta) {
206		debug_putstr("No relocation needed... ");
207		return;
208	}
209	debug_putstr("Performing relocations... ");
210
211	/*
212	 * Process relocations: 32 bit relocations first then 64 bit after.
213	 * Three sets of binary relocations are added to the end of the kernel
214	 * before compression. Each relocation table entry is the kernel
215	 * address of the location which needs to be updated stored as a
216	 * 32-bit value which is sign extended to 64 bits.
217	 *
218	 * Format is:
219	 *
220	 * kernel bits...
221	 * 0 - zero terminator for 64 bit relocations
222	 * 64 bit relocation repeated
223	 * 0 - zero terminator for inverse 32 bit relocations
224	 * 32 bit inverse relocation repeated
225	 * 0 - zero terminator for 32 bit relocations
226	 * 32 bit relocation repeated
227	 *
228	 * So we work backwards from the end of the decompressed image.
229	 */
230	for (reloc = output + output_len - sizeof(*reloc); *reloc; reloc--) {
231		long extended = *reloc;
232		extended += map;
233
234		ptr = (unsigned long)extended;
235		if (ptr < min_addr || ptr > max_addr)
236			error("32-bit relocation outside of kernel!\n");
237
238		*(uint32_t *)ptr += delta;
239	}
240#ifdef CONFIG_X86_64
241	while (*--reloc) {
242		long extended = *reloc;
243		extended += map;
244
245		ptr = (unsigned long)extended;
246		if (ptr < min_addr || ptr > max_addr)
247			error("inverse 32-bit relocation outside of kernel!\n");
248
249		*(int32_t *)ptr -= delta;
250	}
251	for (reloc--; *reloc; reloc--) {
252		long extended = *reloc;
253		extended += map;
254
255		ptr = (unsigned long)extended;
256		if (ptr < min_addr || ptr > max_addr)
257			error("64-bit relocation outside of kernel!\n");
258
259		*(uint64_t *)ptr += delta;
260	}
261#endif
262}
263#else
264static inline void handle_relocations(void *output, unsigned long output_len,
265				      unsigned long virt_addr)
266{ }
267#endif
268
269static void parse_elf(void *output)
270{
271#ifdef CONFIG_X86_64
272	Elf64_Ehdr ehdr;
273	Elf64_Phdr *phdrs, *phdr;
274#else
275	Elf32_Ehdr ehdr;
276	Elf32_Phdr *phdrs, *phdr;
277#endif
278	void *dest;
279	int i;
280
281	memcpy(&ehdr, output, sizeof(ehdr));
282	if (ehdr.e_ident[EI_MAG0] != ELFMAG0 ||
283	   ehdr.e_ident[EI_MAG1] != ELFMAG1 ||
284	   ehdr.e_ident[EI_MAG2] != ELFMAG2 ||
285	   ehdr.e_ident[EI_MAG3] != ELFMAG3) {
286		error("Kernel is not a valid ELF file");
287		return;
288	}
289
290	debug_putstr("Parsing ELF... ");
291
292	phdrs = malloc(sizeof(*phdrs) * ehdr.e_phnum);
293	if (!phdrs)
294		error("Failed to allocate space for phdrs");
295
296	memcpy(phdrs, output + ehdr.e_phoff, sizeof(*phdrs) * ehdr.e_phnum);
297
298	for (i = 0; i < ehdr.e_phnum; i++) {
299		phdr = &phdrs[i];
300
301		switch (phdr->p_type) {
302		case PT_LOAD:
303#ifdef CONFIG_X86_64
304			if ((phdr->p_align % 0x200000) != 0)
305				error("Alignment of LOAD segment isn't multiple of 2MB");
306#endif
307#ifdef CONFIG_RELOCATABLE
308			dest = output;
309			dest += (phdr->p_paddr - LOAD_PHYSICAL_ADDR);
310#else
311			dest = (void *)(phdr->p_paddr);
312#endif
313			memmove(dest, output + phdr->p_offset, phdr->p_filesz);
314			break;
315		default: /* Ignore other PT_* */ break;
316		}
317	}
318
319	free(phdrs);
320}
321
322/*
323 * The compressed kernel image (ZO), has been moved so that its position
324 * is against the end of the buffer used to hold the uncompressed kernel
325 * image (VO) and the execution environment (.bss, .brk), which makes sure
326 * there is room to do the in-place decompression. (See header.S for the
327 * calculations.)
328 *
329 *                             |-----compressed kernel image------|
330 *                             V                                  V
331 * 0                       extract_offset                      +INIT_SIZE
332 * |-----------|---------------|-------------------------|--------|
333 *             |               |                         |        |
334 *           VO__text      startup_32 of ZO          VO__end    ZO__end
335 *             ^                                         ^
336 *             |-------uncompressed kernel image---------|
337 *
338 */
339asmlinkage __visible void *extract_kernel(void *rmode, memptr heap,
340				  unsigned char *input_data,
341				  unsigned long input_len,
342				  unsigned char *output,
343				  unsigned long output_len)
344{
345	const unsigned long kernel_total_size = VO__end - VO__text;
346	unsigned long virt_addr = LOAD_PHYSICAL_ADDR;
 
347
348	/* Retain x86 boot parameters pointer passed from startup_32/64. */
349	boot_params = rmode;
350
351	/* Clear flags intended for solely in-kernel use. */
352	boot_params->hdr.loadflags &= ~KASLR_FLAG;
353
354	sanitize_boot_params(boot_params);
355
356	if (boot_params->screen_info.orig_video_mode == 7) {
357		vidmem = (char *) 0xb0000;
358		vidport = 0x3b4;
359	} else {
360		vidmem = (char *) 0xb8000;
361		vidport = 0x3d4;
362	}
363
364	lines = boot_params->screen_info.orig_video_lines;
365	cols = boot_params->screen_info.orig_video_cols;
366
 
 
 
 
 
 
 
 
 
 
367	console_init();
 
 
 
 
 
 
 
 
368	debug_putstr("early console in extract_kernel\n");
369
370	free_mem_ptr     = heap;	/* Heap */
371	free_mem_end_ptr = heap + BOOT_HEAP_SIZE;
372
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
373	/* Report initial kernel position details. */
374	debug_putaddr(input_data);
375	debug_putaddr(input_len);
376	debug_putaddr(output);
377	debug_putaddr(output_len);
378	debug_putaddr(kernel_total_size);
 
379
380#ifdef CONFIG_X86_64
381	/* Report address of 32-bit trampoline */
382	debug_putaddr(trampoline_32bit);
383#endif
384
385	/*
386	 * The memory hole needed for the kernel is the larger of either
387	 * the entire decompressed kernel plus relocation table, or the
388	 * entire decompressed kernel plus .bss and .brk sections.
389	 */
390	choose_random_location((unsigned long)input_data, input_len,
391				(unsigned long *)&output,
392				max(output_len, kernel_total_size),
393				&virt_addr);
394
395	/* Validate memory location choices. */
396	if ((unsigned long)output & (MIN_KERNEL_ALIGN - 1))
397		error("Destination physical address inappropriately aligned");
398	if (virt_addr & (MIN_KERNEL_ALIGN - 1))
399		error("Destination virtual address inappropriately aligned");
400#ifdef CONFIG_X86_64
401	if (heap > 0x3fffffffffffUL)
402		error("Destination address too large");
403	if (virt_addr + max(output_len, kernel_total_size) > KERNEL_IMAGE_SIZE)
404		error("Destination virtual address is beyond the kernel mapping area");
405#else
406	if (heap > ((-__PAGE_OFFSET-(128<<20)-1) & 0x7fffffff))
407		error("Destination address too large");
408#endif
409#ifndef CONFIG_RELOCATABLE
410	if ((unsigned long)output != LOAD_PHYSICAL_ADDR)
411		error("Destination address does not match LOAD_PHYSICAL_ADDR");
412	if (virt_addr != LOAD_PHYSICAL_ADDR)
413		error("Destination virtual address changed when not relocatable");
414#endif
415
416	debug_putstr("\nDecompressing Linux... ");
417	__decompress(input_data, input_len, NULL, NULL, output, output_len,
418			NULL, error);
419	parse_elf(output);
420	handle_relocations(output, output_len, virt_addr);
421	debug_putstr("done.\nBooting the kernel.\n");
 
 
 
 
422	return output;
423}
424
425void fortify_panic(const char *name)
426{
427	error("detected buffer overflow");
428}