elf.c

   1 /*\r
   2  * Acess2 Kernel\r
   3  * - By John Hodge (thePowersGang)\r
   4  *\r
   5  * elf.c\r
   6  * - ELF Executable Loader Code\r
   7  */\r
   8 #define DEBUG   0\r
   9 #include <acess.h>\r
  10 #include <binary.h>\r
  11 \r
  12 // ---- Import linking code from userland\r
  13 #define _COMMON_H\r
  14 #define SysDebug(v...)  LOG(v)\r
  15 #if BITS <= 32\r
  16 # define DISABLE_ELF64\r
  17 #endif\r
  18 static int      GetSymbol(const char *Name, void **Value, size_t *Size);\r
  19 static int      GetSymbol(const char *Name, void **Value, size_t *Size) {\r
  20         Uint val;\r
  21         if(!Binary_GetSymbol(Name, &val)) {\r
  22                 Log_Notice("ELF", "Lookup of '%s' failed", Name);\r
  23                 return 0;\r
  24         }\r
  25         if(Size)\r
  26                 *Size=0;\r
  27         *Value = (void*)val;\r
  28         return 1;\r
  29 }\r
  30 #define AddLoaded(a,b)  do{}while(0)\r
  31 #define LoadLibrary(a,b,c)      (Log_Debug("ELF", "Module requested lib '%s'",a),0)\r
  32 #define _SysSetMemFlags(ad,f,m) do{}while(0)\r
  33 #include "../../../Usermode/Libraries/ld-acess.so_src/elf.c"\r
  34 // ---- / ----\r
  35 \r
  36 #define DEBUG_WARN      1\r
  37 \r
  38 // === PROTOTYPES ===\r
  39 tBinary *Elf_Load(int fp);\r
  40 tBinary *Elf_Load64(int fp, Elf64_Ehdr *hdr);\r
  41 tBinary *Elf_Load32(int fp, Elf32_Ehdr *hdr);\r
  42  int    Elf_Relocate(void *Base);\r
  43  int    Elf_GetSymbol(void *Base, const char *Name, Uint *Ret);\r
  44 Uint    Elf_Int_HashString(const char *str);\r
  45 \r
  46 // === GLOBALS ===\r
  47 tBinaryType     gELF_Info = {\r
  48         NULL,\r
  49         0x464C457F, 0xFFFFFFFF, // '\x7FELF'\r
  50         "ELF",\r
  51         Elf_Load, Elf_Relocate, Elf_GetSymbol\r
  52         };\r
  53 \r
  54 // === CODE ===\r
  55 tBinary *Elf_Load(int fp)\r
  56 {\r
  57         Elf64_Ehdr      hdr;\r
  58         \r
  59         // Read ELF Header\r
  60         VFS_Read(fp, sizeof(hdr), &hdr);\r
  61         \r
  62         // Check the file type\r
  63         if(hdr.e_ident[0] != 0x7F || hdr.e_ident[1] != 'E' || hdr.e_ident[2] != 'L' || hdr.e_ident[3] != 'F') {\r
  64                 Log_Warning("ELF", "Non-ELF File was passed to the ELF loader");\r
  65                 return NULL;\r
  66         }\r
  67 \r
  68         switch(hdr.e_ident[4])  // EI_CLASS\r
  69         {\r
  70         case ELFCLASS32:\r
  71                 return Elf_Load32(fp, (void*)&hdr);\r
  72         case ELFCLASS64:\r
  73                 return Elf_Load64(fp, &hdr);\r
  74         default:\r
  75                 Log_Warning("ELF", "Unknown EI_CLASS value %i", hdr.e_ident[4]);\r
  76                 return NULL;\r
  77         }\r
  78 }\r
  79 \r
  80 tBinary *Elf_Load64(int FD, Elf64_Ehdr *Header)\r
  81 {\r
  82         tBinary *ret;\r
  83         Elf64_Phdr      phtab[Header->e_phnum];\r
  84          int    nLoadSegments;\r
  85          int    i, j;\r
  86         \r
  87         // Sanity check\r
  88         if( Header->e_phoff == 0 )\r
  89         {\r
  90                 Log_Warning("ELF", "No program header, panic!");\r
  91                 return NULL;\r
  92         }\r
  93         if( Header->e_shentsize != sizeof(Elf64_Shdr) ) {\r
  94                 Log_Warning("ELF", "Header gives shentsize as %i, my type is %i",\r
  95                         Header->e_shentsize, sizeof(Elf64_Shdr) );\r
  96         }\r
  97         if( Header->e_phentsize != sizeof(Elf64_Phdr) ) {\r
  98                 Log_Warning("ELF", "Header gives phentsize as %i, my type is %i",\r
  99                         Header->e_phentsize, sizeof(Elf64_Phdr) );\r
 100         }\r
 101 \r
 102         LOG("Header = {");\r
 103         LOG("  e_ident = %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x",\r
 104                 Header->e_ident[0], Header->e_ident[1], Header->e_ident[2], Header->e_ident[3],\r
 105                 Header->e_ident[4], Header->e_ident[5], Header->e_ident[6], Header->e_ident[7],\r
 106                 Header->e_ident[8], Header->e_ident[9], Header->e_ident[10], Header->e_ident[11],\r
 107                 Header->e_ident[12], Header->e_ident[13], Header->e_ident[14], Header->e_ident[15]\r
 108                 );\r
 109         LOG("  e_type = %i", Header->e_type);\r
 110         LOG("  e_machine = %i", Header->e_machine);\r
 111         LOG("  e_version = %i", Header->e_version);\r
 112         LOG("  e_entry   = 0x%llx", Header->e_entry);\r
 113         LOG("  e_phoff   = 0x%llx", Header->e_phoff);\r
 114         LOG("  e_shoff   = 0x%llx", Header->e_shoff);\r
 115         LOG("  e_flags   = 0x%x", Header->e_flags);\r
 116         LOG("  e_ehsize  = %i", Header->e_ehsize);\r
 117         LOG("  e_phentsize = %i", Header->e_phentsize);\r
 118         LOG("  e_phnum   = %i", Header->e_phnum);\r
 119         LOG("  e_shentsize = %i", Header->e_shentsize);\r
 120         LOG("  e_shnum   = %i", Header->e_shnum);\r
 121         LOG("  e_shstrndx = %i", Header->e_shstrndx);\r
 122         LOG("}");\r
 123 \r
 124         // Load Program Header table\r
 125         VFS_Seek(FD, Header->e_phoff, SEEK_SET);\r
 126         VFS_Read(FD, sizeof(Elf64_Phdr)*Header->e_phnum, phtab);\r
 127 \r
 128         // Count load segments\r
 129         nLoadSegments = 0;\r
 130         for( i = 0; i < Header->e_phnum; i ++ )\r
 131         {\r
 132                 if( phtab[i].p_type != PT_LOAD )        continue ;\r
 133                 nLoadSegments ++;\r
 134         }\r
 135         \r
 136         // Allocate Information Structure\r
 137         ret = malloc( sizeof(tBinary) + sizeof(tBinarySection)*nLoadSegments );\r
 138         // Fill Info Struct\r
 139         ret->Entry = Header->e_entry;\r
 140         ret->Base = -1;         // Set Base to maximum value\r
 141         ret->NumSections = nLoadSegments;\r
 142         ret->Interpreter = NULL;\r
 143 \r
 144         j = 0;  // LoadSections[] index\r
 145         for( i = 0; i < Header->e_phnum; i ++ )\r
 146         {\r
 147                 LOG("phtab[%i] = {", i);\r
 148                 LOG("  .p_type   = %i", phtab[i].p_type);\r
 149                 LOG("  .p_flags  = 0x%x", phtab[i].p_flags);\r
 150                 LOG("  .p_offset = 0x%llx", phtab[i].p_offset);\r
 151                 LOG("  .p_vaddr  = 0x%llx", phtab[i].p_vaddr);\r
 152                 LOG("  .p_paddr  = 0x%llx", phtab[i].p_paddr);\r
 153                 LOG("  .p_filesz = 0x%llx", phtab[i].p_filesz);\r
 154                 LOG("  .p_memsz  = 0x%llx", phtab[i].p_memsz);\r
 155                 LOG("  .p_align  = 0x%llx", phtab[i].p_align);\r
 156                 LOG("}");\r
 157 \r
 158                 // Get Interpreter Name\r
 159                 if( phtab[i].p_type == PT_INTERP )\r
 160                 {\r
 161                         char *tmp;\r
 162                         if(ret->Interpreter)    continue;\r
 163                         tmp = malloc(phtab[i].p_filesz);\r
 164                         VFS_Seek(FD, phtab[i].p_offset, 1);\r
 165                         VFS_Read(FD, phtab[i].p_filesz, tmp);\r
 166                         ret->Interpreter = Binary_RegInterp(tmp);\r
 167                         LOG("Interpreter '%s'", tmp);\r
 168                         free(tmp);\r
 169                         continue;\r
 170                 }\r
 171                 \r
 172                 if( phtab[i].p_type != PT_LOAD )        continue ;\r
 173                 \r
 174                 // Find the executable base\r
 175                 if( phtab[i].p_vaddr < ret->Base )      ret->Base = phtab[i].p_vaddr;\r
 176 \r
 177                 ret->LoadSections[j].Offset = phtab[i].p_offset;\r
 178                 ret->LoadSections[j].Virtual = phtab[i].p_vaddr;\r
 179                 ret->LoadSections[j].FileSize = phtab[i].p_filesz;\r
 180                 ret->LoadSections[j].MemSize = phtab[i].p_memsz;\r
 181                 \r
 182                 ret->LoadSections[j].Flags = 0;\r
 183                 if( !(phtab[i].p_flags & PF_W) )\r
 184                         ret->LoadSections[j].Flags |= BIN_SECTFLAG_RO;\r
 185                 if( phtab[i].p_flags & PF_X )\r
 186                         ret->LoadSections[j].Flags |= BIN_SECTFLAG_EXEC;\r
 187                 j ++;\r
 188         }\r
 189 \r
 190         return ret;\r
 191 }\r
 192 \r
 193 tBinary *Elf_Load32(int FD, Elf32_Ehdr *Header)\r
 194 {\r
 195         tBinary *ret;\r
 196         Elf32_Phdr      *phtab;\r
 197          int    i, j;\r
 198          int    iLoadCount;\r
 199 \r
 200         ENTER("xFD", FD);\r
 201 \r
 202         // Check architecture with current CPU\r
 203         // - TODO: Support kernel level emulation\r
 204         #if ARCH_IS_x86\r
 205         if( Header->machine != EM_386 )\r
 206         {\r
 207                 Log_Warning("ELF", "Unknown architecure on ELF-32");\r
 208                 LEAVE_RET('n');\r
 209                 return NULL;\r
 210         }\r
 211         #endif\r
 212 \r
 213         // Check for a program header\r
 214         if(Header->phoff == 0) {\r
 215                 #if DEBUG_WARN\r
 216                 Log_Warning("ELF", "File does not contain a program header (phoff == 0)");\r
 217                 #endif\r
 218                 LEAVE('n');\r
 219                 return NULL;\r
 220         }\r
 221         \r
 222         // Read Program Header Table\r
 223         phtab = malloc( sizeof(Elf32_Phdr) * Header->phentcount );\r
 224         if( !phtab ) {\r
 225                 LEAVE('n');\r
 226                 return NULL;\r
 227         }\r
 228         LOG("hdr.phoff = 0x%08x", Header->phoff);\r
 229         VFS_Seek(FD, Header->phoff, SEEK_SET);\r
 230         VFS_Read(FD, sizeof(Elf32_Phdr)*Header->phentcount, phtab);\r
 231         \r
 232         // Count Pages\r
 233         iLoadCount = 0;\r
 234         LOG("Header->phentcount = %i", Header->phentcount);\r
 235         for( i = 0; i < Header->phentcount; i++ )\r
 236         {\r
 237                 // Ignore Non-LOAD types\r
 238                 if(phtab[i].Type != PT_LOAD)\r
 239                         continue;\r
 240                 iLoadCount ++;\r
 241                 LOG("phtab[%i] = {VAddr:0x%x, MemSize:0x%x}", i, phtab[i].VAddr, phtab[i].MemSize);\r
 242         }\r
 243         \r
 244         LOG("iLoadCount = %i", iLoadCount);\r
 245         \r
 246         // Allocate Information Structure\r
 247         ret = malloc( sizeof(tBinary) + sizeof(tBinarySection)*iLoadCount );\r
 248         // Fill Info Struct\r
 249         ret->Entry = Header->entrypoint;\r
 250         ret->Base = -1;         // Set Base to maximum value\r
 251         ret->NumSections = iLoadCount;\r
 252         ret->Interpreter = NULL;\r
 253         \r
 254         // Load Pages\r
 255         j = 0;\r
 256         for( i = 0; i < Header->phentcount; i++ )\r
 257         {\r
 258                 //LOG("phtab[%i].Type = 0x%x", i, phtab[i].Type);\r
 259                 LOG("phtab[%i] = {", i);\r
 260                 LOG(" .Type = 0x%08x", phtab[i].Type);\r
 261                 LOG(" .Offset = 0x%08x", phtab[i].Offset);\r
 262                 LOG(" .VAddr = 0x%08x", phtab[i].VAddr);\r
 263                 LOG(" .PAddr = 0x%08x", phtab[i].PAddr);\r
 264                 LOG(" .FileSize = 0x%08x", phtab[i].FileSize);\r
 265                 LOG(" .MemSize = 0x%08x", phtab[i].MemSize);\r
 266                 LOG(" .Flags = 0x%08x", phtab[i].Flags);\r
 267                 LOG(" .Align = 0x%08x", phtab[i].Align);\r
 268                 LOG(" }");\r
 269                 // Get Interpreter Name\r
 270                 if( phtab[i].Type == PT_INTERP )\r
 271                 {\r
 272                         char *tmp;\r
 273                         if(ret->Interpreter)    continue;\r
 274                         tmp = malloc(phtab[i].FileSize);\r
 275                         VFS_Seek(FD, phtab[i].Offset, 1);\r
 276                         VFS_Read(FD, phtab[i].FileSize, tmp);\r
 277                         ret->Interpreter = Binary_RegInterp(tmp);\r
 278                         LOG("Interpreter '%s'", tmp);\r
 279                         free(tmp);\r
 280                         continue;\r
 281                 }\r
 282                 // Ignore non-LOAD types\r
 283                 if(phtab[i].Type != PT_LOAD)    continue;\r
 284                 \r
 285                 // Find Base\r
 286                 if(phtab[i].VAddr < ret->Base)  ret->Base = phtab[i].VAddr;\r
 287                 \r
 288                 LOG("phtab[%i] = {VAddr:0x%x,Offset:0x%x,FileSize:0x%x}",\r
 289                         i, phtab[i].VAddr, phtab[i].Offset, phtab[i].FileSize);\r
 290                 \r
 291                 ret->LoadSections[j].Offset = phtab[i].Offset;\r
 292                 ret->LoadSections[j].FileSize = phtab[i].FileSize;\r
 293                 ret->LoadSections[j].Virtual = phtab[i].VAddr;\r
 294                 ret->LoadSections[j].MemSize = phtab[i].MemSize;\r
 295                 ret->LoadSections[j].Flags = 0;\r
 296                 if( !(phtab[i].Flags & PF_W) )\r
 297                         ret->LoadSections[j].Flags |= BIN_SECTFLAG_RO;\r
 298                 if( phtab[i].Flags & PF_X )\r
 299                         ret->LoadSections[j].Flags |= BIN_SECTFLAG_EXEC;\r
 300                 j ++;\r
 301         }\r
 302         \r
 303         // Clean Up\r
 304         free(phtab);\r
 305         // Return\r
 306         LEAVE('p', ret);\r
 307         return ret;\r
 308 }\r
 309 \r
 310 int Elf_Relocate(void *Base)\r
 311 {\r
 312         return ElfRelocate(Base, (char**){NULL}, "") != NULL;\r
 313 }\r
 314 int Elf_GetSymbol(void *Base, const char *Name, Uint *ret)\r
 315 {\r
 316         return ElfGetSymbol(Base, Name, (void**)ret, NULL);\r
 317 }\r
 318 \r