1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * sorttable.c: Sort the kernel's table
4 *
5 * Added ORC unwind tables sort support and other updates:
6 * Copyright (C) 1999-2019 Alibaba Group Holding Limited. by:
7 * Shile Zhang <shile.zhang@linux.alibaba.com>
8 *
9 * Copyright 2011 - 2012 Cavium, Inc.
10 *
11 * Based on code taken from recortmcount.c which is:
12 *
13 * Copyright 2009 John F. Reiser <jreiser@BitWagon.com>.  All rights reserved.
14 *
15 * Restructured to fit Linux format, as well as other updates:
16 * Copyright 2010 Steven Rostedt <srostedt@redhat.com>, Red Hat Inc.
17 */
18
19/*
20 * Strategy: alter the vmlinux file in-place.
21 */
22
23#include <sys/types.h>
24#include <sys/mman.h>
25#include <sys/stat.h>
26#include <getopt.h>
27#include <elf.h>
28#include <fcntl.h>
29#include <stdio.h>
30#include <stdlib.h>
31#include <string.h>
32#include <unistd.h>
33#include <errno.h>
34#include <pthread.h>
35
36#include <tools/be_byteshift.h>
37#include <tools/le_byteshift.h>
38
39#ifndef EM_ARCOMPACT
40#define EM_ARCOMPACT	93
41#endif
42
43#ifndef EM_XTENSA
44#define EM_XTENSA	94
45#endif
46
47#ifndef EM_AARCH64
48#define EM_AARCH64	183
49#endif
50
51#ifndef EM_MICROBLAZE
52#define EM_MICROBLAZE	189
53#endif
54
55#ifndef EM_ARCV2
56#define EM_ARCV2	195
57#endif
58
59#ifndef EM_RISCV
60#define EM_RISCV	243
61#endif
62
63#ifndef EM_LOONGARCH
64#define EM_LOONGARCH	258
65#endif
66
67static uint32_t (*r)(const uint32_t *);
68static uint16_t (*r2)(const uint16_t *);
69static uint64_t (*r8)(const uint64_t *);
70static void (*w)(uint32_t, uint32_t *);
71static void (*w2)(uint16_t, uint16_t *);
72static void (*w8)(uint64_t, uint64_t *);
73typedef void (*table_sort_t)(char *, int);
74
75/*
76 * Get the whole file as a programming convenience in order to avoid
77 * malloc+lseek+read+free of many pieces.  If successful, then mmap
78 * avoids copying unused pieces; else just read the whole file.
79 * Open for both read and write.
80 */
81static void *mmap_file(char const *fname, size_t *size)
82{
83	int fd;
84	struct stat sb;
85	void *addr = NULL;
86
87	fd = open(fname, O_RDWR);
88	if (fd < 0) {
89		perror(fname);
90		return NULL;
91	}
92	if (fstat(fd, &sb) < 0) {
93		perror(fname);
94		goto out;
95	}
96	if (!S_ISREG(sb.st_mode)) {
97		fprintf(stderr, "not a regular file: %s\n", fname);
98		goto out;
99	}
100
101	addr = mmap(0, sb.st_size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
102	if (addr == MAP_FAILED) {
103		fprintf(stderr, "Could not mmap file: %s\n", fname);
104		goto out;
105	}
106
107	*size = sb.st_size;
108
109out:
110	close(fd);
111	return addr;
112}
113
114static uint32_t rbe(const uint32_t *x)
115{
116	return get_unaligned_be32(x);
117}
118
119static uint16_t r2be(const uint16_t *x)
120{
121	return get_unaligned_be16(x);
122}
123
124static uint64_t r8be(const uint64_t *x)
125{
126	return get_unaligned_be64(x);
127}
128
129static uint32_t rle(const uint32_t *x)
130{
131	return get_unaligned_le32(x);
132}
133
134static uint16_t r2le(const uint16_t *x)
135{
136	return get_unaligned_le16(x);
137}
138
139static uint64_t r8le(const uint64_t *x)
140{
141	return get_unaligned_le64(x);
142}
143
144static void wbe(uint32_t val, uint32_t *x)
145{
146	put_unaligned_be32(val, x);
147}
148
149static void w2be(uint16_t val, uint16_t *x)
150{
151	put_unaligned_be16(val, x);
152}
153
154static void w8be(uint64_t val, uint64_t *x)
155{
156	put_unaligned_be64(val, x);
157}
158
159static void wle(uint32_t val, uint32_t *x)
160{
161	put_unaligned_le32(val, x);
162}
163
164static void w2le(uint16_t val, uint16_t *x)
165{
166	put_unaligned_le16(val, x);
167}
168
169static void w8le(uint64_t val, uint64_t *x)
170{
171	put_unaligned_le64(val, x);
172}
173
174/*
175 * Move reserved section indices SHN_LORESERVE..SHN_HIRESERVE out of
176 * the way to -256..-1, to avoid conflicting with real section
177 * indices.
178 */
179#define SPECIAL(i) ((i) - (SHN_HIRESERVE + 1))
180
181static inline int is_shndx_special(unsigned int i)
182{
183	return i != SHN_XINDEX && i >= SHN_LORESERVE && i <= SHN_HIRESERVE;
184}
185
186/* Accessor for sym->st_shndx, hides ugliness of "64k sections" */
187static inline unsigned int get_secindex(unsigned int shndx,
188					unsigned int sym_offs,
189					const Elf32_Word *symtab_shndx_start)
190{
191	if (is_shndx_special(shndx))
192		return SPECIAL(shndx);
193	if (shndx != SHN_XINDEX)
194		return shndx;
195	return r(&symtab_shndx_start[sym_offs]);
196}
197
198/* 32 bit and 64 bit are very similar */
199#include "sorttable.h"
200#define SORTTABLE_64
201#include "sorttable.h"
202
203static int compare_relative_table(const void *a, const void *b)
204{
205	int32_t av = (int32_t)r(a);
206	int32_t bv = (int32_t)r(b);
207
208	if (av < bv)
209		return -1;
210	if (av > bv)
211		return 1;
212	return 0;
213}
214
215static void sort_relative_table(char *extab_image, int image_size)
216{
217	int i = 0;
218
219	/*
220	 * Do the same thing the runtime sort does, first normalize to
221	 * being relative to the start of the section.
222	 */
223	while (i < image_size) {
224		uint32_t *loc = (uint32_t *)(extab_image + i);
225		w(r(loc) + i, loc);
226		i += 4;
227	}
228
229	qsort(extab_image, image_size / 8, 8, compare_relative_table);
230
231	/* Now denormalize. */
232	i = 0;
233	while (i < image_size) {
234		uint32_t *loc = (uint32_t *)(extab_image + i);
235		w(r(loc) - i, loc);
236		i += 4;
237	}
238}
239
240static void sort_relative_table_with_data(char *extab_image, int image_size)
241{
242	int i = 0;
243
244	while (i < image_size) {
245		uint32_t *loc = (uint32_t *)(extab_image + i);
246
247		w(r(loc) + i, loc);
248		w(r(loc + 1) + i + 4, loc + 1);
249		/* Don't touch the fixup type or data */
250
251		i += sizeof(uint32_t) * 3;
252	}
253
254	qsort(extab_image, image_size / 12, 12, compare_relative_table);
255
256	i = 0;
257	while (i < image_size) {
258		uint32_t *loc = (uint32_t *)(extab_image + i);
259
260		w(r(loc) - i, loc);
261		w(r(loc + 1) - (i + 4), loc + 1);
262		/* Don't touch the fixup type or data */
263
264		i += sizeof(uint32_t) * 3;
265	}
266}
267
268static int do_file(char const *const fname, void *addr)
269{
270	int rc = -1;
271	Elf32_Ehdr *ehdr = addr;
272	table_sort_t custom_sort = NULL;
273
274	switch (ehdr->e_ident[EI_DATA]) {
275	case ELFDATA2LSB:
276		r	= rle;
277		r2	= r2le;
278		r8	= r8le;
279		w	= wle;
280		w2	= w2le;
281		w8	= w8le;
282		break;
283	case ELFDATA2MSB:
284		r	= rbe;
285		r2	= r2be;
286		r8	= r8be;
287		w	= wbe;
288		w2	= w2be;
289		w8	= w8be;
290		break;
291	default:
292		fprintf(stderr, "unrecognized ELF data encoding %d: %s\n",
293			ehdr->e_ident[EI_DATA], fname);
294		return -1;
295	}
296
297	if (memcmp(ELFMAG, ehdr->e_ident, SELFMAG) != 0 ||
298	    (r2(&ehdr->e_type) != ET_EXEC && r2(&ehdr->e_type) != ET_DYN) ||
299	    ehdr->e_ident[EI_VERSION] != EV_CURRENT) {
300		fprintf(stderr, "unrecognized ET_EXEC/ET_DYN file %s\n", fname);
301		return -1;
302	}
303
304	switch (r2(&ehdr->e_machine)) {
305	case EM_386:
306	case EM_AARCH64:
307	case EM_LOONGARCH:
308	case EM_RISCV:
309	case EM_S390:
310	case EM_X86_64:
311		custom_sort = sort_relative_table_with_data;
312		break;
313	case EM_PARISC:
314	case EM_PPC:
315	case EM_PPC64:
316		custom_sort = sort_relative_table;
317		break;
318	case EM_ARCOMPACT:
319	case EM_ARCV2:
320	case EM_ARM:
321	case EM_MICROBLAZE:
322	case EM_MIPS:
323	case EM_XTENSA:
324		break;
325	default:
326		fprintf(stderr, "unrecognized e_machine %d %s\n",
327			r2(&ehdr->e_machine), fname);
328		return -1;
329	}
330
331	switch (ehdr->e_ident[EI_CLASS]) {
332	case ELFCLASS32:
333		if (r2(&ehdr->e_ehsize) != sizeof(Elf32_Ehdr) ||
334		    r2(&ehdr->e_shentsize) != sizeof(Elf32_Shdr)) {
335			fprintf(stderr,
336				"unrecognized ET_EXEC/ET_DYN file: %s\n", fname);
337			break;
338		}
339		rc = do_sort_32(ehdr, fname, custom_sort);
340		break;
341	case ELFCLASS64:
342		{
343		Elf64_Ehdr *const ghdr = (Elf64_Ehdr *)ehdr;
344		if (r2(&ghdr->e_ehsize) != sizeof(Elf64_Ehdr) ||
345		    r2(&ghdr->e_shentsize) != sizeof(Elf64_Shdr)) {
346			fprintf(stderr,
347				"unrecognized ET_EXEC/ET_DYN file: %s\n",
348				fname);
349			break;
350		}
351		rc = do_sort_64(ghdr, fname, custom_sort);
352		}
353		break;
354	default:
355		fprintf(stderr, "unrecognized ELF class %d %s\n",
356			ehdr->e_ident[EI_CLASS], fname);
357		break;
358	}
359
360	return rc;
361}
362
363int main(int argc, char *argv[])
364{
365	int i, n_error = 0;  /* gcc-4.3.0 false positive complaint */
366	size_t size = 0;
367	void *addr = NULL;
368
369	if (argc < 2) {
370		fprintf(stderr, "usage: sorttable vmlinux...\n");
371		return 0;
372	}
373
374	/* Process each file in turn, allowing deep failure. */
375	for (i = 1; i < argc; i++) {
376		addr = mmap_file(argv[i], &size);
377		if (!addr) {
378			++n_error;
379			continue;
380		}
381
382		if (do_file(argv[i], addr))
383			++n_error;
384
385		munmap(addr, size);
386	}
387
388	return !!n_error;
389}
390