These changes are a raw update to a vanilla kernel 4.1.10, with the
[kvmfornfv.git] / kernel / scripts / sortextable.c
1 /*
2  * sortextable.c: Sort the kernel's exception table
3  *
4  * Copyright 2011 - 2012 Cavium, Inc.
5  *
6  * Based on code taken from recortmcount.c which is:
7  *
8  * Copyright 2009 John F. Reiser <jreiser@BitWagon.com>.  All rights reserved.
9  * Licensed under the GNU General Public License, version 2 (GPLv2).
10  *
11  * Restructured to fit Linux format, as well as other updates:
12  *  Copyright 2010 Steven Rostedt <srostedt@redhat.com>, Red Hat Inc.
13  */
14
15 /*
16  * Strategy: alter the vmlinux file in-place.
17  */
18
19 #include <sys/types.h>
20 #include <sys/mman.h>
21 #include <sys/stat.h>
22 #include <getopt.h>
23 #include <elf.h>
24 #include <fcntl.h>
25 #include <setjmp.h>
26 #include <stdio.h>
27 #include <stdlib.h>
28 #include <string.h>
29 #include <unistd.h>
30
31 #include <tools/be_byteshift.h>
32 #include <tools/le_byteshift.h>
33
34 #ifndef EM_ARCOMPACT
35 #define EM_ARCOMPACT    93
36 #endif
37
38 #ifndef EM_XTENSA
39 #define EM_XTENSA       94
40 #endif
41
42 #ifndef EM_AARCH64
43 #define EM_AARCH64      183
44 #endif
45
46 #ifndef EM_MICROBLAZE
47 #define EM_MICROBLAZE   189
48 #endif
49
50 static int fd_map;      /* File descriptor for file being modified. */
51 static int mmap_failed; /* Boolean flag. */
52 static void *ehdr_curr; /* current ElfXX_Ehdr *  for resource cleanup */
53 static struct stat sb;  /* Remember .st_size, etc. */
54 static jmp_buf jmpenv;  /* setjmp/longjmp per-file error escape */
55
56 /* setjmp() return values */
57 enum {
58         SJ_SETJMP = 0,  /* hardwired first return */
59         SJ_FAIL,
60         SJ_SUCCEED
61 };
62
63 /* Per-file resource cleanup when multiple files. */
64 static void
65 cleanup(void)
66 {
67         if (!mmap_failed)
68                 munmap(ehdr_curr, sb.st_size);
69         close(fd_map);
70 }
71
72 static void __attribute__((noreturn))
73 fail_file(void)
74 {
75         cleanup();
76         longjmp(jmpenv, SJ_FAIL);
77 }
78
79 /*
80  * Get the whole file as a programming convenience in order to avoid
81  * malloc+lseek+read+free of many pieces.  If successful, then mmap
82  * avoids copying unused pieces; else just read the whole file.
83  * Open for both read and write.
84  */
85 static void *mmap_file(char const *fname)
86 {
87         void *addr;
88
89         fd_map = open(fname, O_RDWR);
90         if (fd_map < 0 || fstat(fd_map, &sb) < 0) {
91                 perror(fname);
92                 fail_file();
93         }
94         if (!S_ISREG(sb.st_mode)) {
95                 fprintf(stderr, "not a regular file: %s\n", fname);
96                 fail_file();
97         }
98         addr = mmap(0, sb.st_size, PROT_READ|PROT_WRITE, MAP_SHARED,
99                     fd_map, 0);
100         if (addr == MAP_FAILED) {
101                 mmap_failed = 1;
102                 fprintf(stderr, "Could not mmap file: %s\n", fname);
103                 fail_file();
104         }
105         return addr;
106 }
107
108 static uint64_t r8be(const uint64_t *x)
109 {
110         return get_unaligned_be64(x);
111 }
112 static uint32_t rbe(const uint32_t *x)
113 {
114         return get_unaligned_be32(x);
115 }
116 static uint16_t r2be(const uint16_t *x)
117 {
118         return get_unaligned_be16(x);
119 }
120 static uint64_t r8le(const uint64_t *x)
121 {
122         return get_unaligned_le64(x);
123 }
124 static uint32_t rle(const uint32_t *x)
125 {
126         return get_unaligned_le32(x);
127 }
128 static uint16_t r2le(const uint16_t *x)
129 {
130         return get_unaligned_le16(x);
131 }
132
133 static void w8be(uint64_t val, uint64_t *x)
134 {
135         put_unaligned_be64(val, x);
136 }
137 static void wbe(uint32_t val, uint32_t *x)
138 {
139         put_unaligned_be32(val, x);
140 }
141 static void w2be(uint16_t val, uint16_t *x)
142 {
143         put_unaligned_be16(val, x);
144 }
145 static void w8le(uint64_t val, uint64_t *x)
146 {
147         put_unaligned_le64(val, x);
148 }
149 static void wle(uint32_t val, uint32_t *x)
150 {
151         put_unaligned_le32(val, x);
152 }
153 static void w2le(uint16_t val, uint16_t *x)
154 {
155         put_unaligned_le16(val, x);
156 }
157
158 static uint64_t (*r8)(const uint64_t *);
159 static uint32_t (*r)(const uint32_t *);
160 static uint16_t (*r2)(const uint16_t *);
161 static void (*w8)(uint64_t, uint64_t *);
162 static void (*w)(uint32_t, uint32_t *);
163 static void (*w2)(uint16_t, uint16_t *);
164
165 typedef void (*table_sort_t)(char *, int);
166
167 /*
168  * Move reserved section indices SHN_LORESERVE..SHN_HIRESERVE out of
169  * the way to -256..-1, to avoid conflicting with real section
170  * indices.
171  */
172 #define SPECIAL(i) ((i) - (SHN_HIRESERVE + 1))
173
174 static inline int is_shndx_special(unsigned int i)
175 {
176         return i != SHN_XINDEX && i >= SHN_LORESERVE && i <= SHN_HIRESERVE;
177 }
178
179 /* Accessor for sym->st_shndx, hides ugliness of "64k sections" */
180 static inline unsigned int get_secindex(unsigned int shndx,
181                                         unsigned int sym_offs,
182                                         const Elf32_Word *symtab_shndx_start)
183 {
184         if (is_shndx_special(shndx))
185                 return SPECIAL(shndx);
186         if (shndx != SHN_XINDEX)
187                 return shndx;
188         return r(&symtab_shndx_start[sym_offs]);
189 }
190
191 /* 32 bit and 64 bit are very similar */
192 #include "sortextable.h"
193 #define SORTEXTABLE_64
194 #include "sortextable.h"
195
196 static int compare_relative_table(const void *a, const void *b)
197 {
198         int32_t av = (int32_t)r(a);
199         int32_t bv = (int32_t)r(b);
200
201         if (av < bv)
202                 return -1;
203         if (av > bv)
204                 return 1;
205         return 0;
206 }
207
208 static void sort_relative_table(char *extab_image, int image_size)
209 {
210         int i;
211
212         /*
213          * Do the same thing the runtime sort does, first normalize to
214          * being relative to the start of the section.
215          */
216         i = 0;
217         while (i < image_size) {
218                 uint32_t *loc = (uint32_t *)(extab_image + i);
219                 w(r(loc) + i, loc);
220                 i += 4;
221         }
222
223         qsort(extab_image, image_size / 8, 8, compare_relative_table);
224
225         /* Now denormalize. */
226         i = 0;
227         while (i < image_size) {
228                 uint32_t *loc = (uint32_t *)(extab_image + i);
229                 w(r(loc) - i, loc);
230                 i += 4;
231         }
232 }
233
234 static void
235 do_file(char const *const fname)
236 {
237         table_sort_t custom_sort;
238         Elf32_Ehdr *ehdr = mmap_file(fname);
239
240         ehdr_curr = ehdr;
241         switch (ehdr->e_ident[EI_DATA]) {
242         default:
243                 fprintf(stderr, "unrecognized ELF data encoding %d: %s\n",
244                         ehdr->e_ident[EI_DATA], fname);
245                 fail_file();
246                 break;
247         case ELFDATA2LSB:
248                 r = rle;
249                 r2 = r2le;
250                 r8 = r8le;
251                 w = wle;
252                 w2 = w2le;
253                 w8 = w8le;
254                 break;
255         case ELFDATA2MSB:
256                 r = rbe;
257                 r2 = r2be;
258                 r8 = r8be;
259                 w = wbe;
260                 w2 = w2be;
261                 w8 = w8be;
262                 break;
263         }  /* end switch */
264         if (memcmp(ELFMAG, ehdr->e_ident, SELFMAG) != 0
265         ||  r2(&ehdr->e_type) != ET_EXEC
266         ||  ehdr->e_ident[EI_VERSION] != EV_CURRENT) {
267                 fprintf(stderr, "unrecognized ET_EXEC file %s\n", fname);
268                 fail_file();
269         }
270
271         custom_sort = NULL;
272         switch (r2(&ehdr->e_machine)) {
273         default:
274                 fprintf(stderr, "unrecognized e_machine %d %s\n",
275                         r2(&ehdr->e_machine), fname);
276                 fail_file();
277                 break;
278         case EM_386:
279         case EM_X86_64:
280         case EM_S390:
281                 custom_sort = sort_relative_table;
282                 break;
283         case EM_ARCOMPACT:
284         case EM_ARM:
285         case EM_AARCH64:
286         case EM_MICROBLAZE:
287         case EM_MIPS:
288         case EM_XTENSA:
289                 break;
290         }  /* end switch */
291
292         switch (ehdr->e_ident[EI_CLASS]) {
293         default:
294                 fprintf(stderr, "unrecognized ELF class %d %s\n",
295                         ehdr->e_ident[EI_CLASS], fname);
296                 fail_file();
297                 break;
298         case ELFCLASS32:
299                 if (r2(&ehdr->e_ehsize) != sizeof(Elf32_Ehdr)
300                 ||  r2(&ehdr->e_shentsize) != sizeof(Elf32_Shdr)) {
301                         fprintf(stderr,
302                                 "unrecognized ET_EXEC file: %s\n", fname);
303                         fail_file();
304                 }
305                 do32(ehdr, fname, custom_sort);
306                 break;
307         case ELFCLASS64: {
308                 Elf64_Ehdr *const ghdr = (Elf64_Ehdr *)ehdr;
309                 if (r2(&ghdr->e_ehsize) != sizeof(Elf64_Ehdr)
310                 ||  r2(&ghdr->e_shentsize) != sizeof(Elf64_Shdr)) {
311                         fprintf(stderr,
312                                 "unrecognized ET_EXEC file: %s\n", fname);
313                         fail_file();
314                 }
315                 do64(ghdr, fname, custom_sort);
316                 break;
317         }
318         }  /* end switch */
319
320         cleanup();
321 }
322
323 int
324 main(int argc, char *argv[])
325 {
326         int n_error = 0;  /* gcc-4.3.0 false positive complaint */
327         int i;
328
329         if (argc < 2) {
330                 fprintf(stderr, "usage: sortextable vmlinux...\n");
331                 return 0;
332         }
333
334         /* Process each file in turn, allowing deep failure. */
335         for (i = 1; i < argc; i++) {
336                 char *file = argv[i];
337                 int const sjval = setjmp(jmpenv);
338
339                 switch (sjval) {
340                 default:
341                         fprintf(stderr, "internal error: %s\n", file);
342                         exit(1);
343                         break;
344                 case SJ_SETJMP:    /* normal sequence */
345                         /* Avoid problems if early cleanup() */
346                         fd_map = -1;
347                         ehdr_curr = NULL;
348                         mmap_failed = 1;
349                         do_file(file);
350                         break;
351                 case SJ_FAIL:    /* error in do_file or below */
352                         ++n_error;
353                         break;
354                 case SJ_SUCCEED:    /* premature success */
355                         /* do nothing */
356                         break;
357                 }  /* end switch */
358         }
359         return !!n_error;
360 }