Adding packet forward test cases involving multiple VMs
[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 #ifndef EM_ARCV2
51 #define EM_ARCV2        195
52 #endif
53
54 static int fd_map;      /* File descriptor for file being modified. */
55 static int mmap_failed; /* Boolean flag. */
56 static void *ehdr_curr; /* current ElfXX_Ehdr *  for resource cleanup */
57 static struct stat sb;  /* Remember .st_size, etc. */
58 static jmp_buf jmpenv;  /* setjmp/longjmp per-file error escape */
59
60 /* setjmp() return values */
61 enum {
62         SJ_SETJMP = 0,  /* hardwired first return */
63         SJ_FAIL,
64         SJ_SUCCEED
65 };
66
67 /* Per-file resource cleanup when multiple files. */
68 static void
69 cleanup(void)
70 {
71         if (!mmap_failed)
72                 munmap(ehdr_curr, sb.st_size);
73         close(fd_map);
74 }
75
76 static void __attribute__((noreturn))
77 fail_file(void)
78 {
79         cleanup();
80         longjmp(jmpenv, SJ_FAIL);
81 }
82
83 /*
84  * Get the whole file as a programming convenience in order to avoid
85  * malloc+lseek+read+free of many pieces.  If successful, then mmap
86  * avoids copying unused pieces; else just read the whole file.
87  * Open for both read and write.
88  */
89 static void *mmap_file(char const *fname)
90 {
91         void *addr;
92
93         fd_map = open(fname, O_RDWR);
94         if (fd_map < 0 || fstat(fd_map, &sb) < 0) {
95                 perror(fname);
96                 fail_file();
97         }
98         if (!S_ISREG(sb.st_mode)) {
99                 fprintf(stderr, "not a regular file: %s\n", fname);
100                 fail_file();
101         }
102         addr = mmap(0, sb.st_size, PROT_READ|PROT_WRITE, MAP_SHARED,
103                     fd_map, 0);
104         if (addr == MAP_FAILED) {
105                 mmap_failed = 1;
106                 fprintf(stderr, "Could not mmap file: %s\n", fname);
107                 fail_file();
108         }
109         return addr;
110 }
111
112 static uint64_t r8be(const uint64_t *x)
113 {
114         return get_unaligned_be64(x);
115 }
116 static uint32_t rbe(const uint32_t *x)
117 {
118         return get_unaligned_be32(x);
119 }
120 static uint16_t r2be(const uint16_t *x)
121 {
122         return get_unaligned_be16(x);
123 }
124 static uint64_t r8le(const uint64_t *x)
125 {
126         return get_unaligned_le64(x);
127 }
128 static uint32_t rle(const uint32_t *x)
129 {
130         return get_unaligned_le32(x);
131 }
132 static uint16_t r2le(const uint16_t *x)
133 {
134         return get_unaligned_le16(x);
135 }
136
137 static void w8be(uint64_t val, uint64_t *x)
138 {
139         put_unaligned_be64(val, x);
140 }
141 static void wbe(uint32_t val, uint32_t *x)
142 {
143         put_unaligned_be32(val, x);
144 }
145 static void w2be(uint16_t val, uint16_t *x)
146 {
147         put_unaligned_be16(val, x);
148 }
149 static void w8le(uint64_t val, uint64_t *x)
150 {
151         put_unaligned_le64(val, x);
152 }
153 static void wle(uint32_t val, uint32_t *x)
154 {
155         put_unaligned_le32(val, x);
156 }
157 static void w2le(uint16_t val, uint16_t *x)
158 {
159         put_unaligned_le16(val, x);
160 }
161
162 static uint64_t (*r8)(const uint64_t *);
163 static uint32_t (*r)(const uint32_t *);
164 static uint16_t (*r2)(const uint16_t *);
165 static void (*w8)(uint64_t, uint64_t *);
166 static void (*w)(uint32_t, uint32_t *);
167 static void (*w2)(uint16_t, uint16_t *);
168
169 typedef void (*table_sort_t)(char *, int);
170
171 /*
172  * Move reserved section indices SHN_LORESERVE..SHN_HIRESERVE out of
173  * the way to -256..-1, to avoid conflicting with real section
174  * indices.
175  */
176 #define SPECIAL(i) ((i) - (SHN_HIRESERVE + 1))
177
178 static inline int is_shndx_special(unsigned int i)
179 {
180         return i != SHN_XINDEX && i >= SHN_LORESERVE && i <= SHN_HIRESERVE;
181 }
182
183 /* Accessor for sym->st_shndx, hides ugliness of "64k sections" */
184 static inline unsigned int get_secindex(unsigned int shndx,
185                                         unsigned int sym_offs,
186                                         const Elf32_Word *symtab_shndx_start)
187 {
188         if (is_shndx_special(shndx))
189                 return SPECIAL(shndx);
190         if (shndx != SHN_XINDEX)
191                 return shndx;
192         return r(&symtab_shndx_start[sym_offs]);
193 }
194
195 /* 32 bit and 64 bit are very similar */
196 #include "sortextable.h"
197 #define SORTEXTABLE_64
198 #include "sortextable.h"
199
200 static int compare_relative_table(const void *a, const void *b)
201 {
202         int32_t av = (int32_t)r(a);
203         int32_t bv = (int32_t)r(b);
204
205         if (av < bv)
206                 return -1;
207         if (av > bv)
208                 return 1;
209         return 0;
210 }
211
212 static void sort_relative_table(char *extab_image, int image_size)
213 {
214         int i;
215
216         /*
217          * Do the same thing the runtime sort does, first normalize to
218          * being relative to the start of the section.
219          */
220         i = 0;
221         while (i < image_size) {
222                 uint32_t *loc = (uint32_t *)(extab_image + i);
223                 w(r(loc) + i, loc);
224                 i += 4;
225         }
226
227         qsort(extab_image, image_size / 8, 8, compare_relative_table);
228
229         /* Now denormalize. */
230         i = 0;
231         while (i < image_size) {
232                 uint32_t *loc = (uint32_t *)(extab_image + i);
233                 w(r(loc) - i, loc);
234                 i += 4;
235         }
236 }
237
238 static void
239 do_file(char const *const fname)
240 {
241         table_sort_t custom_sort;
242         Elf32_Ehdr *ehdr = mmap_file(fname);
243
244         ehdr_curr = ehdr;
245         switch (ehdr->e_ident[EI_DATA]) {
246         default:
247                 fprintf(stderr, "unrecognized ELF data encoding %d: %s\n",
248                         ehdr->e_ident[EI_DATA], fname);
249                 fail_file();
250                 break;
251         case ELFDATA2LSB:
252                 r = rle;
253                 r2 = r2le;
254                 r8 = r8le;
255                 w = wle;
256                 w2 = w2le;
257                 w8 = w8le;
258                 break;
259         case ELFDATA2MSB:
260                 r = rbe;
261                 r2 = r2be;
262                 r8 = r8be;
263                 w = wbe;
264                 w2 = w2be;
265                 w8 = w8be;
266                 break;
267         }  /* end switch */
268         if (memcmp(ELFMAG, ehdr->e_ident, SELFMAG) != 0
269         ||  r2(&ehdr->e_type) != ET_EXEC
270         ||  ehdr->e_ident[EI_VERSION] != EV_CURRENT) {
271                 fprintf(stderr, "unrecognized ET_EXEC file %s\n", fname);
272                 fail_file();
273         }
274
275         custom_sort = NULL;
276         switch (r2(&ehdr->e_machine)) {
277         default:
278                 fprintf(stderr, "unrecognized e_machine %d %s\n",
279                         r2(&ehdr->e_machine), fname);
280                 fail_file();
281                 break;
282         case EM_386:
283         case EM_X86_64:
284         case EM_S390:
285                 custom_sort = sort_relative_table;
286                 break;
287         case EM_ARCOMPACT:
288         case EM_ARCV2:
289         case EM_ARM:
290         case EM_AARCH64:
291         case EM_MICROBLAZE:
292         case EM_MIPS:
293         case EM_XTENSA:
294                 break;
295         }  /* end switch */
296
297         switch (ehdr->e_ident[EI_CLASS]) {
298         default:
299                 fprintf(stderr, "unrecognized ELF class %d %s\n",
300                         ehdr->e_ident[EI_CLASS], fname);
301                 fail_file();
302                 break;
303         case ELFCLASS32:
304                 if (r2(&ehdr->e_ehsize) != sizeof(Elf32_Ehdr)
305                 ||  r2(&ehdr->e_shentsize) != sizeof(Elf32_Shdr)) {
306                         fprintf(stderr,
307                                 "unrecognized ET_EXEC file: %s\n", fname);
308                         fail_file();
309                 }
310                 do32(ehdr, fname, custom_sort);
311                 break;
312         case ELFCLASS64: {
313                 Elf64_Ehdr *const ghdr = (Elf64_Ehdr *)ehdr;
314                 if (r2(&ghdr->e_ehsize) != sizeof(Elf64_Ehdr)
315                 ||  r2(&ghdr->e_shentsize) != sizeof(Elf64_Shdr)) {
316                         fprintf(stderr,
317                                 "unrecognized ET_EXEC file: %s\n", fname);
318                         fail_file();
319                 }
320                 do64(ghdr, fname, custom_sort);
321                 break;
322         }
323         }  /* end switch */
324
325         cleanup();
326 }
327
328 int
329 main(int argc, char *argv[])
330 {
331         int n_error = 0;  /* gcc-4.3.0 false positive complaint */
332         int i;
333
334         if (argc < 2) {
335                 fprintf(stderr, "usage: sortextable vmlinux...\n");
336                 return 0;
337         }
338
339         /* Process each file in turn, allowing deep failure. */
340         for (i = 1; i < argc; i++) {
341                 char *file = argv[i];
342                 int const sjval = setjmp(jmpenv);
343
344                 switch (sjval) {
345                 default:
346                         fprintf(stderr, "internal error: %s\n", file);
347                         exit(1);
348                         break;
349                 case SJ_SETJMP:    /* normal sequence */
350                         /* Avoid problems if early cleanup() */
351                         fd_map = -1;
352                         ehdr_curr = NULL;
353                         mmap_failed = 1;
354                         do_file(file);
355                         break;
356                 case SJ_FAIL:    /* error in do_file or below */
357                         ++n_error;
358                         break;
359                 case SJ_SUCCEED:    /* premature success */
360                         /* do nothing */
361                         break;
362                 }  /* end switch */
363         }
364         return !!n_error;
365 }