buildtools/pmdinfogen/pmdinfogen.c

   1 /* Postprocess pmd object files to export hw support
   2  *
   3  * Copyright 2016 Neil Horman <nhorman@tuxdriver.com>
   4  * Based in part on modpost.c from the linux kernel
   5  *
   6  * This software may be used and distributed according to the terms
   7  * of the GNU General Public License V2, incorporated herein by reference.
   8  *
   9  */
  10
  11 #define _GNU_SOURCE
  12 #include <stdio.h>
  13 #include <ctype.h>
  14 #include <string.h>
  15 #include <limits.h>
  16 #include <stdbool.h>
  17 #include <errno.h>
  18 #include <libgen.h>
  19
  20 #include <rte_common.h>
  21 #include "pmdinfogen.h"
  22
  23 #ifdef RTE_ARCH_64
  24 #define ADDR_SIZE 64
  25 #else
  26 #define ADDR_SIZE 32
  27 #endif
  28
  29
  30 static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
  31 {
  32         if (sym)
  33                 return elf->strtab + sym->st_name;
  34         else
  35                 return "(unknown)";
  36 }
  37
  38 static void *grab_file(const char *filename, unsigned long *size)
  39 {
  40         struct stat st;
  41         void *map = MAP_FAILED;
  42         int fd;
  43
  44         fd = open(filename, O_RDONLY);
  45         if (fd < 0)
  46                 return NULL;
  47         if (fstat(fd, &st))
  48                 goto failed;
  49
  50         *size = st.st_size;
  51         map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
  52
  53 failed:
  54         close(fd);
  55         if (map == MAP_FAILED)
  56                 return NULL;
  57         return map;
  58 }
  59
  60 /**
  61   * Return a copy of the next line in a mmap'ed file.
  62   * spaces in the beginning of the line is trimmed away.
  63   * Return a pointer to a static buffer.
  64   **/
  65 static void release_file(void *file, unsigned long size)
  66 {
  67         munmap(file, size);
  68 }
  69
  70
  71 static void *get_sym_value(struct elf_info *info, const Elf_Sym *sym)
  72 {
  73         return RTE_PTR_ADD(info->hdr,
  74                 info->sechdrs[sym->st_shndx].sh_offset + sym->st_value);
  75 }
  76
  77 static Elf_Sym *find_sym_in_symtab(struct elf_info *info,
  78                                    const char *name, Elf_Sym *last)
  79 {
  80         Elf_Sym *idx;
  81         if (last)
  82                 idx = last+1;
  83         else
  84                 idx = info->symtab_start;
  85
  86         for (; idx < info->symtab_stop; idx++) {
  87                 const char *n = sym_name(info, idx);
  88                 if (!strncmp(n, name, strlen(name)))
  89                         return idx;
  90         }
  91         return NULL;
  92 }
  93
  94 static int parse_elf(struct elf_info *info, const char *filename)
  95 {
  96         unsigned int i;
  97         Elf_Ehdr *hdr;
  98         Elf_Shdr *sechdrs;
  99         Elf_Sym  *sym;
 100         int endian;
 101         unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U;
 102
 103         hdr = grab_file(filename, &info->size);
 104         if (!hdr) {
 105                 perror(filename);
 106                 exit(1);
 107         }
 108         info->hdr = hdr;
 109         if (info->size < sizeof(*hdr)) {
 110                 /* file too small, assume this is an empty .o file */
 111                 return 0;
 112         }
 113         /* Is this a valid ELF file? */
 114         if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
 115             (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
 116             (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
 117             (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
 118                 /* Not an ELF file - silently ignore it */
 119                 return 0;
 120         }
 121
 122         if (!hdr->e_ident[EI_DATA]) {
 123                 /* Unknown endian */
 124                 return 0;
 125         }
 126
 127         endian = hdr->e_ident[EI_DATA];
 128
 129         /* Fix endianness in ELF header */
 130         hdr->e_type      = TO_NATIVE(endian, 16, hdr->e_type);
 131         hdr->e_machine   = TO_NATIVE(endian, 16, hdr->e_machine);
 132         hdr->e_version   = TO_NATIVE(endian, 32, hdr->e_version);
 133         hdr->e_entry     = TO_NATIVE(endian, ADDR_SIZE, hdr->e_entry);
 134         hdr->e_phoff     = TO_NATIVE(endian, ADDR_SIZE, hdr->e_phoff);
 135         hdr->e_shoff     = TO_NATIVE(endian, ADDR_SIZE, hdr->e_shoff);
 136         hdr->e_flags     = TO_NATIVE(endian, 32, hdr->e_flags);
 137         hdr->e_ehsize    = TO_NATIVE(endian, 16, hdr->e_ehsize);
 138         hdr->e_phentsize = TO_NATIVE(endian, 16, hdr->e_phentsize);
 139         hdr->e_phnum     = TO_NATIVE(endian, 16, hdr->e_phnum);
 140         hdr->e_shentsize = TO_NATIVE(endian, 16, hdr->e_shentsize);
 141         hdr->e_shnum     = TO_NATIVE(endian, 16, hdr->e_shnum);
 142         hdr->e_shstrndx  = TO_NATIVE(endian, 16, hdr->e_shstrndx);
 143
 144         sechdrs = RTE_PTR_ADD(hdr, hdr->e_shoff);
 145         info->sechdrs = sechdrs;
 146
 147         /* Check if file offset is correct */
 148         if (hdr->e_shoff > info->size) {
 149                 fprintf(stderr, "section header offset=%lu in file '%s' "
 150                       "is bigger than filesize=%lu\n",
 151                       (unsigned long)hdr->e_shoff,
 152                       filename, info->size);
 153                 return 0;
 154         }
 155
 156         if (hdr->e_shnum == SHN_UNDEF) {
 157                 /*
 158                  * There are more than 64k sections,
 159                  * read count from .sh_size.
 160                  */
 161                 info->num_sections = TO_NATIVE(endian, 32, sechdrs[0].sh_size);
 162         } else {
 163                 info->num_sections = hdr->e_shnum;
 164         }
 165         if (hdr->e_shstrndx == SHN_XINDEX)
 166                 info->secindex_strings =
 167                         TO_NATIVE(endian, 32, sechdrs[0].sh_link);
 168         else
 169                 info->secindex_strings = hdr->e_shstrndx;
 170
 171         /* Fix endianness in section headers */
 172         for (i = 0; i < info->num_sections; i++) {
 173                 sechdrs[i].sh_name      =
 174                         TO_NATIVE(endian, 32, sechdrs[i].sh_name);
 175                 sechdrs[i].sh_type      =
 176                         TO_NATIVE(endian, 32, sechdrs[i].sh_type);
 177                 sechdrs[i].sh_flags     =
 178                         TO_NATIVE(endian, 32, sechdrs[i].sh_flags);
 179                 sechdrs[i].sh_addr      =
 180                         TO_NATIVE(endian, ADDR_SIZE, sechdrs[i].sh_addr);
 181                 sechdrs[i].sh_offset    =
 182                         TO_NATIVE(endian, ADDR_SIZE, sechdrs[i].sh_offset);
 183                 sechdrs[i].sh_size      =
 184                         TO_NATIVE(endian, 32, sechdrs[i].sh_size);
 185                 sechdrs[i].sh_link      =
 186                         TO_NATIVE(endian, 32, sechdrs[i].sh_link);
 187                 sechdrs[i].sh_info      =
 188                         TO_NATIVE(endian, 32, sechdrs[i].sh_info);
 189                 sechdrs[i].sh_addralign =
 190                         TO_NATIVE(endian, ADDR_SIZE, sechdrs[i].sh_addralign);
 191                 sechdrs[i].sh_entsize   =
 192                         TO_NATIVE(endian, ADDR_SIZE, sechdrs[i].sh_entsize);
 193         }
 194         /* Find symbol table. */
 195         for (i = 1; i < info->num_sections; i++) {
 196                 int nobits = sechdrs[i].sh_type == SHT_NOBITS;
 197
 198                 if (!nobits && sechdrs[i].sh_offset > info->size) {
 199                         fprintf(stderr, "%s is truncated. "
 200                               "sechdrs[i].sh_offset=%lu > sizeof(*hrd)=%zu\n",
 201                               filename, (unsigned long)sechdrs[i].sh_offset,
 202                               sizeof(*hdr));
 203                         return 0;
 204                 }
 205
 206                 if (sechdrs[i].sh_type == SHT_SYMTAB) {
 207                         unsigned int sh_link_idx;
 208                         symtab_idx = i;
 209                         info->symtab_start = RTE_PTR_ADD(hdr,
 210                                 sechdrs[i].sh_offset);
 211                         info->symtab_stop  = RTE_PTR_ADD(hdr,
 212                                 sechdrs[i].sh_offset + sechdrs[i].sh_size);
 213                         sh_link_idx = sechdrs[i].sh_link;
 214                         info->strtab       = RTE_PTR_ADD(hdr,
 215                                 sechdrs[sh_link_idx].sh_offset);
 216                 }
 217
 218                 /* 32bit section no. table? ("more than 64k sections") */
 219                 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) {
 220                         symtab_shndx_idx = i;
 221                         info->symtab_shndx_start = RTE_PTR_ADD(hdr,
 222                                 sechdrs[i].sh_offset);
 223                         info->symtab_shndx_stop  = RTE_PTR_ADD(hdr,
 224                                 sechdrs[i].sh_offset + sechdrs[i].sh_size);
 225                 }
 226         }
 227         if (!info->symtab_start)
 228                 fprintf(stderr, "%s has no symtab?\n", filename);
 229         else {
 230                 /* Fix endianness in symbols */
 231                 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
 232                         sym->st_shndx = TO_NATIVE(endian, 16, sym->st_shndx);
 233                         sym->st_name  = TO_NATIVE(endian, 32, sym->st_name);
 234                         sym->st_value = TO_NATIVE(endian, ADDR_SIZE, sym->st_value);
 235                         sym->st_size  = TO_NATIVE(endian, ADDR_SIZE, sym->st_size);
 236                 }
 237         }
 238
 239         if (symtab_shndx_idx != ~0U) {
 240                 Elf32_Word *p;
 241                 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link)
 242                         fprintf(stderr,
 243                               "%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
 244                               filename, sechdrs[symtab_shndx_idx].sh_link,
 245                               symtab_idx);
 246                 /* Fix endianness */
 247                 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop;
 248                      p++)
 249                         *p = TO_NATIVE(endian, 32, *p);
 250         }
 251
 252         return 1;
 253 }
 254
 255 static void parse_elf_finish(struct elf_info *info)
 256 {
 257         struct pmd_driver *tmp, *idx = info->drivers;
 258         release_file(info->hdr, info->size);
 259         while (idx) {
 260                 tmp = idx->next;
 261                 free(idx);
 262                 idx = tmp;
 263         }
 264 }
 265
 266 struct opt_tag {
 267         const char *suffix;
 268         const char *json_id;
 269 };
 270
 271 static const struct opt_tag opt_tags[] = {
 272         {"_param_string_export", "params"},
 273         {"_kmod_dep_export", "kmod"},
 274 };
 275
 276 static int complete_pmd_entry(struct elf_info *info, struct pmd_driver *drv)
 277 {
 278         const char *tname;
 279         int i;
 280         char tmpsymname[128];
 281         Elf_Sym *tmpsym;
 282
 283         drv->name = get_sym_value(info, drv->name_sym);
 284
 285         for (i = 0; i < PMD_OPT_MAX; i++) {
 286                 memset(tmpsymname, 0, 128);
 287                 sprintf(tmpsymname, "__%s%s", drv->name, opt_tags[i].suffix);
 288                 tmpsym = find_sym_in_symtab(info, tmpsymname, NULL);
 289                 if (!tmpsym)
 290                         continue;
 291                 drv->opt_vals[i] = get_sym_value(info, tmpsym);
 292         }
 293
 294         memset(tmpsymname, 0, 128);
 295         sprintf(tmpsymname, "__%s_pci_tbl_export", drv->name);
 296
 297         tmpsym = find_sym_in_symtab(info, tmpsymname, NULL);
 298
 299
 300         /*
 301          * If this returns NULL, then this is a PMD_VDEV, because
 302          * it has no pci table reference
 303          */
 304         if (!tmpsym) {
 305                 drv->pci_tbl = NULL;
 306                 return 0;
 307         }
 308
 309         tname = get_sym_value(info, tmpsym);
 310         tmpsym = find_sym_in_symtab(info, tname, NULL);
 311         if (!tmpsym)
 312                 return -ENOENT;
 313
 314         drv->pci_tbl = (struct rte_pci_id *)get_sym_value(info, tmpsym);
 315         if (!drv->pci_tbl)
 316                 return -ENOENT;
 317
 318         return 0;
 319 }
 320
 321 static int locate_pmd_entries(struct elf_info *info)
 322 {
 323         Elf_Sym *last = NULL;
 324         struct pmd_driver *new;
 325
 326         info->drivers = NULL;
 327
 328         do {
 329                 new = calloc(sizeof(struct pmd_driver), 1);
 330                 new->name_sym = find_sym_in_symtab(info, "this_pmd_name", last);
 331                 last = new->name_sym;
 332                 if (!new->name_sym)
 333                         free(new);
 334                 else {
 335                         if (complete_pmd_entry(info, new)) {
 336                                 fprintf(stderr,
 337                                         "Failed to complete pmd entry\n");
 338                                 free(new);
 339                         } else {
 340                                 new->next = info->drivers;
 341                                 info->drivers = new;
 342                         }
 343                 }
 344         } while (last);
 345
 346         return 0;
 347 }
 348
 349 static void output_pmd_info_string(struct elf_info *info, char *outfile)
 350 {
 351         FILE *ofd;
 352         struct pmd_driver *drv;
 353         struct rte_pci_id *pci_ids;
 354         int idx = 0;
 355
 356         ofd = fopen(outfile, "w+");
 357         if (!ofd) {
 358                 fprintf(stderr, "Unable to open output file\n");
 359                 return;
 360         }
 361
 362         drv = info->drivers;
 363
 364         while (drv) {
 365                 fprintf(ofd, "const char %s_pmd_info[] __attribute__((used)) = "
 366                         "\"PMD_INFO_STRING= {",
 367                         drv->name);
 368                 fprintf(ofd, "\\\"name\\\" : \\\"%s\\\", ", drv->name);
 369
 370                 for (idx = 0; idx < PMD_OPT_MAX; idx++) {
 371                         if (drv->opt_vals[idx])
 372                                 fprintf(ofd, "\\\"%s\\\" : \\\"%s\\\", ",
 373                                         opt_tags[idx].json_id,
 374                                         drv->opt_vals[idx]);
 375                 }
 376
 377                 pci_ids = drv->pci_tbl;
 378                 fprintf(ofd, "\\\"pci_ids\\\" : [");
 379
 380                 while (pci_ids && pci_ids->device_id) {
 381                         fprintf(ofd, "[%d, %d, %d, %d]",
 382                                 pci_ids->vendor_id, pci_ids->device_id,
 383                                 pci_ids->subsystem_vendor_id,
 384                                 pci_ids->subsystem_device_id);
 385                         pci_ids++;
 386                         if (pci_ids->device_id)
 387                                 fprintf(ofd, ",");
 388                         else
 389                                 fprintf(ofd, " ");
 390                 }
 391                 fprintf(ofd, "]}\";\n");
 392                 drv = drv->next;
 393         }
 394
 395         fclose(ofd);
 396 }
 397
 398 int main(int argc, char **argv)
 399 {
 400         struct elf_info info;
 401         int rc = 1;
 402
 403         if (argc < 3) {
 404                 fprintf(stderr,
 405                         "usage: %s <object file> <c output file>\n",
 406                         basename(argv[0]));
 407                 exit(127);
 408         }
 409         parse_elf(&info, argv[1]);
 410
 411         locate_pmd_entries(&info);
 412
 413         if (info.drivers) {
 414                 output_pmd_info_string(&info, argv[2]);
 415                 rc = 0;
 416         } else {
 417                 fprintf(stderr, "No drivers registered\n");
 418         }
 419
 420         parse_elf_finish(&info);
 421         exit(rc);
 422 }