KernelLand/Kernel/bin/elf.c

   1 /*\r
   2  * Acess v0.1\r
   3  * ELF Executable Loader Code\r
   4  */\r
   5 #define DEBUG   0\r
   6 #include <acess.h>\r
   7 #include <binary.h>\r
   8 \r
   9 #define _COMMON_H\r
  10 #define SysDebug(v...)  LOG(v)\r
  11 #define DISABLE_ELF64\r
  12 void    *GetSymbol(const char *Name, size_t *Size);\r
  13 void    *GetSymbol(const char *Name, size_t *Size) { Uint val; Binary_GetSymbol(Name, &val); if(Size)*Size=0; return (void*)val; };\r
  14 #define AddLoaded(a,b)  do{}while(0)\r
  15 #define LoadLibrary(a,b,c)      0\r
  16 #include "../../../Usermode/Libraries/ld-acess.so_src/elf.c"\r
  17 \r
  18 #define DEBUG_WARN      1\r
  19 \r
  20 // === PROTOTYPES ===\r
  21 tBinary *Elf_Load(int fp);\r
  22 tBinary *Elf_Load64(int fp, Elf64_Ehdr *hdr);\r
  23 tBinary *Elf_Load32(int fp, Elf32_Ehdr *hdr);\r
  24  int    Elf_Relocate(void *Base);\r
  25  int    Elf_GetSymbol(void *Base, const char *Name, Uint *Ret);\r
  26 Uint    Elf_Int_HashString(const char *str);\r
  27 \r
  28 // === GLOBALS ===\r
  29 tBinaryType     gELF_Info = {\r
  30         NULL,\r
  31         0x464C457F, 0xFFFFFFFF, // '\x7FELF'\r
  32         "ELF",\r
  33         Elf_Load, Elf_Relocate, Elf_GetSymbol\r
  34         };\r
  35 \r
  36 // === CODE ===\r
  37 tBinary *Elf_Load(int fp)\r
  38 {\r
  39         Elf64_Ehdr      hdr;\r
  40         \r
  41         // Read ELF Header\r
  42         VFS_Read(fp, sizeof(hdr), &hdr);\r
  43         \r
  44         // Check the file type\r
  45         if(hdr.e_ident[0] != 0x7F || hdr.e_ident[1] != 'E' || hdr.e_ident[2] != 'L' || hdr.e_ident[3] != 'F') {\r
  46                 Log_Warning("ELF", "Non-ELF File was passed to the ELF loader");\r
  47                 return NULL;\r
  48         }\r
  49 \r
  50         switch(hdr.e_ident[4])  // EI_CLASS\r
  51         {\r
  52         case ELFCLASS32:\r
  53                 return Elf_Load32(fp, (void*)&hdr);\r
  54         case ELFCLASS64:\r
  55                 return Elf_Load64(fp, &hdr);\r
  56         default:\r
  57                 Log_Warning("ELF", "Unknown EI_CLASS value %i", hdr.e_ident[4]);\r
  58                 return NULL;\r
  59         }\r
  60 }\r
  61 \r
  62 tBinary *Elf_Load64(int FD, Elf64_Ehdr *Header)\r
  63 {\r
  64         tBinary *ret;\r
  65         Elf64_Phdr      phtab[Header->e_phnum];\r
  66          int    nLoadSegments;\r
  67          int    i, j;\r
  68         \r
  69         // Sanity check\r
  70         if( Header->e_phoff == 0 )\r
  71         {\r
  72                 Log_Warning("ELF", "No program header, panic!");\r
  73                 return NULL;\r
  74         }\r
  75         if( Header->e_shentsize != sizeof(Elf64_Shdr) ) {\r
  76                 Log_Warning("ELF", "Header gives shentsize as %i, my type is %i",\r
  77                         Header->e_shentsize, sizeof(Elf64_Shdr) );\r
  78         }\r
  79         if( Header->e_phentsize != sizeof(Elf64_Phdr) ) {\r
  80                 Log_Warning("ELF", "Header gives phentsize as %i, my type is %i",\r
  81                         Header->e_phentsize, sizeof(Elf64_Phdr) );\r
  82         }\r
  83 \r
  84         LOG("Header = {");\r
  85         LOG("  e_ident = %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x",\r
  86                 Header->e_ident[0], Header->e_ident[1], Header->e_ident[2], Header->e_ident[3],\r
  87                 Header->e_ident[4], Header->e_ident[5], Header->e_ident[6], Header->e_ident[7],\r
  88                 Header->e_ident[8], Header->e_ident[9], Header->e_ident[10], Header->e_ident[11],\r
  89                 Header->e_ident[12], Header->e_ident[13], Header->e_ident[14], Header->e_ident[15]\r
  90                 );\r
  91         LOG("  e_type = %i", Header->e_type);\r
  92         LOG("  e_machine = %i", Header->e_machine);\r
  93         LOG("  e_version = %i", Header->e_version);\r
  94         LOG("  e_entry   = 0x%llx", Header->e_entry);\r
  95         LOG("  e_phoff   = 0x%llx", Header->e_phoff);\r
  96         LOG("  e_shoff   = 0x%llx", Header->e_shoff);\r
  97         LOG("  e_flags   = 0x%x", Header->e_flags);\r
  98         LOG("  e_ehsize  = %i", Header->e_ehsize);\r
  99         LOG("  e_phentsize = %i", Header->e_phentsize);\r
 100         LOG("  e_phnum   = %i", Header->e_phnum);\r
 101         LOG("  e_shentsize = %i", Header->e_shentsize);\r
 102         LOG("  e_shnum   = %i", Header->e_shnum);\r
 103         LOG("  e_shstrndx = %i", Header->e_shstrndx);\r
 104         LOG("}");\r
 105 \r
 106         // Load Program Header table\r
 107         VFS_Seek(FD, Header->e_phoff, SEEK_SET);\r
 108         VFS_Read(FD, sizeof(Elf64_Phdr)*Header->e_phnum, phtab);\r
 109 \r
 110         // Count load segments\r
 111         nLoadSegments = 0;\r
 112         for( i = 0; i < Header->e_phnum; i ++ )\r
 113         {\r
 114                 if( phtab[i].p_type != PT_LOAD )        continue ;\r
 115                 nLoadSegments ++;\r
 116         }\r
 117         \r
 118         // Allocate Information Structure\r
 119         ret = malloc( sizeof(tBinary) + sizeof(tBinarySection)*nLoadSegments );\r
 120         // Fill Info Struct\r
 121         ret->Entry = Header->e_entry;\r
 122         ret->Base = -1;         // Set Base to maximum value\r
 123         ret->NumSections = nLoadSegments;\r
 124         ret->Interpreter = NULL;\r
 125 \r
 126         j = 0;  // LoadSections[] index\r
 127         for( i = 0; i < Header->e_phnum; i ++ )\r
 128         {\r
 129                 LOG("phtab[%i] = {", i);\r
 130                 LOG("  .p_type   = %i", phtab[i].p_type);\r
 131                 LOG("  .p_flags  = 0x%x", phtab[i].p_flags);\r
 132                 LOG("  .p_offset = 0x%llx", phtab[i].p_offset);\r
 133                 LOG("  .p_vaddr  = 0x%llx", phtab[i].p_vaddr);\r
 134                 LOG("  .p_paddr  = 0x%llx", phtab[i].p_paddr);\r
 135                 LOG("  .p_filesz = 0x%llx", phtab[i].p_filesz);\r
 136                 LOG("  .p_memsz  = 0x%llx", phtab[i].p_memsz);\r
 137                 LOG("  .p_align  = 0x%llx", phtab[i].p_align);\r
 138                 LOG("}");\r
 139 \r
 140                 // Get Interpreter Name\r
 141                 if( phtab[i].p_type == PT_INTERP )\r
 142                 {\r
 143                         char *tmp;\r
 144                         if(ret->Interpreter)    continue;\r
 145                         tmp = malloc(phtab[i].p_filesz);\r
 146                         VFS_Seek(FD, phtab[i].p_offset, 1);\r
 147                         VFS_Read(FD, phtab[i].p_filesz, tmp);\r
 148                         ret->Interpreter = Binary_RegInterp(tmp);\r
 149                         LOG("Interpreter '%s'", tmp);\r
 150                         free(tmp);\r
 151                         continue;\r
 152                 }\r
 153                 \r
 154                 if( phtab[i].p_type != PT_LOAD )        continue ;\r
 155                 \r
 156                 // Find the executable base\r
 157                 if( phtab[i].p_vaddr < ret->Base )      ret->Base = phtab[i].p_vaddr;\r
 158 \r
 159                 ret->LoadSections[j].Offset = phtab[i].p_offset;\r
 160                 ret->LoadSections[j].Virtual = phtab[i].p_vaddr;\r
 161                 ret->LoadSections[j].FileSize = phtab[i].p_filesz;\r
 162                 ret->LoadSections[j].MemSize = phtab[i].p_memsz;\r
 163                 \r
 164                 ret->LoadSections[j].Flags = 0;\r
 165                 if( !(phtab[i].p_flags & PF_W) )\r
 166                         ret->LoadSections[j].Flags |= BIN_SECTFLAG_RO;\r
 167                 if( phtab[i].p_flags & PF_X )\r
 168                         ret->LoadSections[j].Flags |= BIN_SECTFLAG_EXEC;\r
 169                 j ++;\r
 170         }\r
 171 \r
 172         return ret;\r
 173 }\r
 174 \r
 175 tBinary *Elf_Load32(int FD, Elf32_Ehdr *Header)\r
 176 {\r
 177         tBinary *ret;\r
 178         Elf32_Phdr      *phtab;\r
 179          int    i, j;\r
 180          int    iLoadCount;\r
 181 \r
 182         ENTER("xFD", FD);\r
 183 \r
 184         // Check architecture with current CPU\r
 185         // - TODO: Support kernel level emulation\r
 186         #if ARCH_IS_x86\r
 187         if( Header->machine != EM_386 )\r
 188         {\r
 189                 Log_Warning("ELF", "Unknown architecure on ELF-32");\r
 190                 LEAVE_RET('n');\r
 191                 return NULL;\r
 192         }\r
 193         #endif\r
 194 \r
 195         // Check for a program header\r
 196         if(Header->phoff == 0) {\r
 197                 #if DEBUG_WARN\r
 198                 Log_Warning("ELF", "File does not contain a program header (phoff == 0)");\r
 199                 #endif\r
 200                 LEAVE('n');\r
 201                 return NULL;\r
 202         }\r
 203         \r
 204         // Read Program Header Table\r
 205         phtab = malloc( sizeof(Elf32_Phdr) * Header->phentcount );\r
 206         if( !phtab ) {\r
 207                 LEAVE('n');\r
 208                 return NULL;\r
 209         }\r
 210         LOG("hdr.phoff = 0x%08x", Header->phoff);\r
 211         VFS_Seek(FD, Header->phoff, SEEK_SET);\r
 212         VFS_Read(FD, sizeof(Elf32_Phdr)*Header->phentcount, phtab);\r
 213         \r
 214         // Count Pages\r
 215         iLoadCount = 0;\r
 216         LOG("Header->phentcount = %i", Header->phentcount);\r
 217         for( i = 0; i < Header->phentcount; i++ )\r
 218         {\r
 219                 // Ignore Non-LOAD types\r
 220                 if(phtab[i].Type != PT_LOAD)\r
 221                         continue;\r
 222                 iLoadCount ++;\r
 223                 LOG("phtab[%i] = {VAddr:0x%x, MemSize:0x%x}", i, phtab[i].VAddr, phtab[i].MemSize);\r
 224         }\r
 225         \r
 226         LOG("iLoadCount = %i", iLoadCount);\r
 227         \r
 228         // Allocate Information Structure\r
 229         ret = malloc( sizeof(tBinary) + sizeof(tBinarySection)*iLoadCount );\r
 230         // Fill Info Struct\r
 231         ret->Entry = Header->entrypoint;\r
 232         ret->Base = -1;         // Set Base to maximum value\r
 233         ret->NumSections = iLoadCount;\r
 234         ret->Interpreter = NULL;\r
 235         \r
 236         // Load Pages\r
 237         j = 0;\r
 238         for( i = 0; i < Header->phentcount; i++ )\r
 239         {\r
 240                 //LOG("phtab[%i].Type = 0x%x", i, phtab[i].Type);\r
 241                 LOG("phtab[%i] = {", i);\r
 242                 LOG(" .Type = 0x%08x", phtab[i].Type);\r
 243                 LOG(" .Offset = 0x%08x", phtab[i].Offset);\r
 244                 LOG(" .VAddr = 0x%08x", phtab[i].VAddr);\r
 245                 LOG(" .PAddr = 0x%08x", phtab[i].PAddr);\r
 246                 LOG(" .FileSize = 0x%08x", phtab[i].FileSize);\r
 247                 LOG(" .MemSize = 0x%08x", phtab[i].MemSize);\r
 248                 LOG(" .Flags = 0x%08x", phtab[i].Flags);\r
 249                 LOG(" .Align = 0x%08x", phtab[i].Align);\r
 250                 LOG(" }");\r
 251                 // Get Interpreter Name\r
 252                 if( phtab[i].Type == PT_INTERP )\r
 253                 {\r
 254                         char *tmp;\r
 255                         if(ret->Interpreter)    continue;\r
 256                         tmp = malloc(phtab[i].FileSize);\r
 257                         VFS_Seek(FD, phtab[i].Offset, 1);\r
 258                         VFS_Read(FD, phtab[i].FileSize, tmp);\r
 259                         ret->Interpreter = Binary_RegInterp(tmp);\r
 260                         LOG("Interpreter '%s'", tmp);\r
 261                         free(tmp);\r
 262                         continue;\r
 263                 }\r
 264                 // Ignore non-LOAD types\r
 265                 if(phtab[i].Type != PT_LOAD)    continue;\r
 266                 \r
 267                 // Find Base\r
 268                 if(phtab[i].VAddr < ret->Base)  ret->Base = phtab[i].VAddr;\r
 269                 \r
 270                 LOG("phtab[%i] = {VAddr:0x%x,Offset:0x%x,FileSize:0x%x}",\r
 271                         i, phtab[i].VAddr, phtab[i].Offset, phtab[i].FileSize);\r
 272                 \r
 273                 ret->LoadSections[j].Offset = phtab[i].Offset;\r
 274                 ret->LoadSections[j].FileSize = phtab[i].FileSize;\r
 275                 ret->LoadSections[j].Virtual = phtab[i].VAddr;\r
 276                 ret->LoadSections[j].MemSize = phtab[i].MemSize;\r
 277                 ret->LoadSections[j].Flags = 0;\r
 278                 if( !(phtab[i].Flags & PF_W) )\r
 279                         ret->LoadSections[j].Flags |= BIN_SECTFLAG_RO;\r
 280                 if( phtab[i].Flags & PF_X )\r
 281                         ret->LoadSections[j].Flags |= BIN_SECTFLAG_EXEC;\r
 282                 j ++;\r
 283         }\r
 284         \r
 285         // Clean Up\r
 286         free(phtab);\r
 287         // Return\r
 288         LEAVE('p', ret);\r
 289         return ret;\r
 290 }\r
 291 \r
 292 int Elf_Relocate(void *Base)\r
 293 {\r
 294         return  ElfRelocate(Base, (char**){NULL}, "") != NULL;\r
 295 }\r
 296 int Elf_GetSymbol(void *Base, const char *Name, Uint *ret)\r
 297 {\r
 298         return ElfGetSymbol(Base, Name, (void**)ret, NULL);\r
 299 }\r
 300 \r