src/util/iccfix.c

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