gpxe/src/util/iccfix.c

   1 #include <stdint.h>
   2 #include <stddef.h>
   3 #include <stdio.h>
   4 #include <stdlib.h>
   5 #include <unistd.h>
   6 #include <fcntl.h>
   7 #include <errno.h>
   8 #include <sys/types.h>
   9 #include <sys/stat.h>
  10 #include <sys/mman.h>
  11 #include <elf.h>
  12 #include <gpxe/tables.h>
  13
  14 #define DEBUG 0
  15
  16 #define eprintf(...) fprintf ( stderr, __VA_ARGS__ )
  17
  18 #define dprintf(...) do {                                               \
  19         if ( DEBUG )                                                    \
  20                 fprintf ( stderr, __VA_ARGS__ );                        \
  21         } while ( 0 )
  22
  23 #ifdef SELF_INCLUDED
  24
  25 /**
  26  * Fix up ICC alignments
  27  *
  28  * @v elf               ELF header
  29  * @ret rc              Return status code
  30  *
  31  * See comments in tables.h for an explanation of why this monstrosity
  32  * is necessary.
  33  */
  34 static int ICCFIX ( void *elf ) {
  35         ELF_EHDR *ehdr = elf;
  36         ELF_SHDR *shdr = ( elf + ehdr->e_shoff );
  37         size_t shentsize = ehdr->e_shentsize;
  38         unsigned int shnum = ehdr->e_shnum;
  39         ELF_SHDR *strtab = ( ( ( void * ) shdr ) +
  40                              ( ehdr->e_shstrndx * shentsize ) );
  41         char *strings = ( elf + strtab->sh_offset );
  42
  43         for ( ; shnum-- ; shdr = ( ( ( void * ) shdr ) + shentsize ) ) {
  44                 char *name = ( strings + shdr->sh_name );
  45                 unsigned long align = shdr->sh_addralign;
  46                 unsigned long new_align;
  47
  48                 if ( ( strncmp ( name, ".tbl.", 5 ) == 0 ) &&
  49                      ( align >= ICC_ALIGN_HACK_FACTOR ) ) {
  50                         new_align = ( align / ICC_ALIGN_HACK_FACTOR );
  51                         shdr->sh_addralign = new_align;
  52                         dprintf ( "Section \"%s\": alignment %d->%d\n",
  53                                   name, align, new_align );
  54                 }
  55         }
  56         return 0;
  57 }
  58
  59 #else /* SELF_INCLUDED */
  60
  61 #define SELF_INCLUDED
  62
  63 /* Include iccfix32() function */
  64 #define ELF_EHDR Elf32_Ehdr
  65 #define ELF_SHDR Elf32_Shdr
  66 #define ICCFIX iccfix32
  67 #include "iccfix.c"
  68 #undef ELF_EHDR
  69 #undef ELF_SHDR
  70 #undef ICCFIX
  71
  72 /* Include iccfix64() function */
  73 #define ELF_EHDR Elf64_Ehdr
  74 #define ELF_SHDR Elf64_Shdr
  75 #define ICCFIX iccfix64
  76 #include "iccfix.c"
  77 #undef ELF_EHDR
  78 #undef ELF_SHDR
  79 #undef ICCFIX
  80
  81 static int iccfix ( const char *filename ) {
  82         int fd;
  83         struct stat stat;
  84         void *elf;
  85         unsigned char *eident;
  86         int rc;
  87
  88         /* Open and mmap file */
  89         fd = open ( filename, O_RDWR );
  90         if ( fd < 0 ) {
  91                 eprintf ( "Could not open %s: %s\n",
  92                           filename, strerror ( errno ) );
  93                 rc = -1;
  94                 goto err_open;
  95         }
  96         if ( fstat ( fd, &stat ) < 0 ) {
  97                 eprintf ( "Could not determine size of %s: %s\n",
  98                           filename, strerror ( errno ) );
  99                 rc = -1;
 100                 goto err_fstat;
 101         }
 102         elf = mmap ( NULL, stat.st_size, ( PROT_READ | PROT_WRITE ),
 103                      MAP_SHARED, fd, 0 );
 104         if ( elf == MAP_FAILED ) {
 105                 eprintf ( "Could not map %s: %s\n",
 106                           filename, strerror ( errno ) );
 107                 rc = -1;
 108                 goto err_mmap;
 109         }
 110
 111         /* Perform fixups */
 112         eident = elf;
 113         switch ( eident[EI_CLASS] ) {
 114         case ELFCLASS32:
 115                 rc = iccfix32 ( elf );
 116                 break;
 117         case ELFCLASS64:
 118                 rc = iccfix64 ( elf );
 119                 break;
 120         default:
 121                 eprintf ( "Unknown ELF class %d in %s\n",
 122                           eident[EI_CLASS], filename );
 123                 rc = -1;
 124                 break;
 125         }
 126
 127         munmap ( elf, stat.st_size );
 128  err_mmap:
 129  err_fstat:
 130         close ( fd );
 131  err_open:
 132         return rc;
 133 }
 134
 135 int main ( int argc, char **argv ) {
 136         int i;
 137         int rc;
 138
 139         /* Parse command line */
 140         if ( argc < 2 ) {
 141                 eprintf ( "Syntax: %s <object_file>...\n", argv[0] );
 142                 exit ( 1 );
 143         }
 144
 145         /* Process each object in turn */
 146         for ( i = 1 ; i < argc ; i++ ) {
 147                 if ( ( rc = iccfix ( argv[i] ) ) != 0 ) {
 148                         eprintf ( "Could not fix up %s\n", argv[i] );
 149                         exit ( 1 );
 150                 }
 151         }
 152
 153         return 0;
 154 }
 155
 156 #endif /* SELF_INCLUDED */