/*
- * AcessOS 1 - Dynamic Loader
- * By thePowersGang
+ * Acess2 Dynamic Linker
+ * - By John Hodge (thePowersGang)
+ *
+ * elf.c
+ * - ELF32/ELF64 relocation
*/
+#ifndef DEBUG // This code is #include'd from the kernel, so DEBUG may already be defined
+# define DEBUG 0
+#endif
+
+#ifndef PAGE_SIZE
+# define PAGE_SIZE 4096
+#endif
+
#include "common.h"
#include <stdint.h>
#include "elf32.h"
#include "elf64.h"
-#define DEBUG 1
-
#if DEBUG
# define DEBUGS(v...) SysDebug("ld-acess - " v)
#else
# define DEBUGS(...)
#endif
+#ifndef DISABLE_ELF64
+# define SUPPORT_ELF64
+#endif
+
// === CONSTANTS ===
#if DEBUG
//static const char *csaDT_NAMES[] = {"DT_NULL", "DT_NEEDED", "DT_PLTRELSZ", "DT_PLTGOT", "DT_HASH", "DT_STRTAB", "DT_SYMTAB", "DT_RELA", "DT_RELASZ", "DT_RELAENT", "DT_STRSZ", "DT_SYMENT", "DT_INIT", "DT_FINI", "DT_SONAME", "DT_RPATH", "DT_SYMBOLIC", "DT_REL", "DT_RELSZ", "DT_RELENT", "DT_PLTREL", "DT_DEBUG", "DT_TEXTREL", "DT_JMPREL"};
// === PROTOTYPES ===
void *ElfRelocate(void *Base, char **envp, const char *Filename);
+ int ElfGetSymbol(void *Base, const char *Name, void **Ret, size_t *Size);
void *Elf32Relocate(void *Base, char **envp, const char *Filename);
+ int Elf32GetSymbol(void *Base, const char *Name, void **Ret, size_t *Size);
+ int elf_doRelocate_386(uint32_t r_info, uint32_t *ptr, Elf32_Addr addend, int type, int bRela, const char *Sym, intptr_t iBaseDiff);
+ int elf_doRelocate_arm(uint32_t r_info, uint32_t *ptr, Elf32_Addr addend, int type, int bRela, const char *Sym, intptr_t iBaseDiff);
+ int elf_doRelocate_unk(uint32_t , uint32_t *, Elf32_Addr , int , int , const char *, intptr_t);
+#ifdef SUPPORT_ELF64
void *Elf64Relocate(void *Base, char **envp, const char *Filename);
-Uint32 ElfHashString(const char *name);
+ int Elf64GetSymbol(void *Base, const char *Name, void **Ret, size_t *Size);
+#endif
+uint32_t ElfHashString(const char *name);
// === CODE ===
/**
{
case ELFCLASS32:
return Elf32Relocate(Base, envp, Filename);
+#ifdef SUPPORT_ELF64
case ELFCLASS64:
return Elf64Relocate(Base, envp, Filename);
+#endif
default:
SysDebug("ld-acess - ElfRelocate: Unknown file class %i", hdr->e_ident[4]);
return NULL;
}
}
-void *Elf64Relocate(void *Base, char **envp, const char *Filename)
+/**
+ * \fn int ElfGetSymbol(Uint Base, const char *name, void **ret)
+ */
+int ElfGetSymbol(void *Base, const char *Name, void **ret, size_t *Size)
{
- int i;
- Elf64_Ehdr *hdr = Base;
- Elf64_Phdr *phtab;
- Elf64_Dyn *dyntab;
- Elf64_Addr compiledBase = -1, baseDiff;
- Elf64_Sym *symtab = NULL;
- char *strtab = NULL;
- Elf64_Word *hashtab = NULL;
- Elf64_Rel *rel = NULL;
- int rel_count = 0;
- Elf64_Rela *rela = NULL;
- int rela_count = 0;
- void *pltrel = NULL;
- int plt_size = 0, plt_type = 0;
-
- DEBUGS("Elf64Relocate: hdr = {");
- DEBUGS("Elf64Relocate: e_ident = '%.16s'", hdr->e_ident);
- DEBUGS("Elf64Relocate: e_type = 0x%x", hdr->e_type);
- DEBUGS("Elf64Relocate: e_machine = 0x%x", hdr->e_machine);
- DEBUGS("Elf64Relocate: e_version = 0x%x", hdr->e_version);
- DEBUGS("Elf64Relocate: e_entry = %p", hdr->e_entry);
- DEBUGS("Elf64Relocate: e_phoff = 0x%llx", hdr->e_phoff);
- DEBUGS("Elf64Relocate: e_shoff = 0x%llx", hdr->e_shoff);
- DEBUGS("Elf64Relocate: e_flags = 0x%x", hdr->e_flags);
- DEBUGS("Elf64Relocate: e_ehsize = 0x%x", hdr->e_ehsize);
- DEBUGS("Elf64Relocate: e_phentsize = 0x%x", hdr->e_phentsize);
- DEBUGS("Elf64Relocate: e_phnum = %i", hdr->e_phnum);
-
- // Scan for the dynamic table (and find the compiled base)
- phtab = Base + hdr->e_phoff;
- for( i = 0; i < hdr->e_phnum; i ++ )
- {
- if(phtab[i].p_type == PT_DYNAMIC)
- dyntab = (void *)phtab[i].p_vaddr;
- if(phtab[i].p_type == PT_LOAD && compiledBase > phtab[i].p_vaddr)
- compiledBase = phtab[i].p_vaddr;
- }
-
- baseDiff = (Elf64_Addr)Base - compiledBase;
-
- DEBUGS("baseDiff = %p", baseDiff);
-
- if(dyntab == NULL) {
- SysDebug(" Elf64Relocate: No PT_DYNAMIC segment in image %p, returning", Base);
- return (void *)(hdr->e_entry + baseDiff);
- }
-
- dyntab = (void *)((Elf64_Addr)dyntab + baseDiff);
+ Elf32_Ehdr *hdr = Base;
- // Parse the dynamic table (first pass)
- // - Search for String, Symbol and Hash tables
- for(i = 0; dyntab[i].d_tag != DT_NULL; i ++)
+ switch(hdr->e_ident[4])
{
- switch(dyntab[i].d_tag)
- {
- case DT_SYMTAB:
- dyntab[i].d_un.d_ptr += baseDiff;
- symtab = (void *)dyntab[i].d_un.d_ptr;
- break;
- case DT_STRTAB:
- dyntab[i].d_un.d_ptr += baseDiff;
- strtab = (void *)dyntab[i].d_un.d_ptr;
- break;
- case DT_HASH:
- dyntab[i].d_un.d_ptr += baseDiff;
- hashtab = (void *)dyntab[i].d_un.d_ptr;
- break;
- }
- }
-
- if( !symtab || !strtab || !hashtab ) {
- SysDebug("ld-acess - Elf64Relocate: Missing Symbol, string or hash table");
- return NULL;
+ case ELFCLASS32:
+ return Elf32GetSymbol(Base, Name, ret, Size);
+#ifdef SUPPORT_ELF64
+ case ELFCLASS64:
+ return Elf64GetSymbol(Base, Name, ret, Size);
+#endif
+ default:
+ SysDebug("ld-acess - ElfRelocate: Unknown file class %i", hdr->e_ident[4]);
+ return 0;
}
+}
- // Ready for symbol use
- AddLoaded( Filename, Base );
-
- // Second pass on dynamic table
- for(i = 0; dyntab[i].d_tag != DT_NULL; i ++)
+int elf_doRelocate_386(uint32_t r_info, uint32_t *ptr, Elf32_Addr addend, int type,
+ int bRela, const char *Sym, intptr_t iBaseDiff)
+{
+ void *symval;
+ switch( type )
{
- DEBUGS("dyntab[%i].d_tag = %i", i, dyntab[i].d_tag);
- switch(dyntab[i].d_tag)
- {
- case DT_SONAME: break;
-
- case DT_NEEDED: {
- char *libPath = strtab + dyntab[i].d_un.d_val;
- DEBUGS("Elf64Relocate: libPath = '%s'", libPath);
- if(LoadLibrary(libPath, NULL, envp) == 0) {
- SysDebug("ld-acess - Elf64Relocate: Unable to load '%s'", libPath);
- return NULL;
- }
- } break;
+ // Standard 32 Bit Relocation (S+A)
+ case R_386_32:
+ if( !GetSymbol(Sym, &symval, NULL) )
+ return 1;
+ DEBUGS(" elf_doRelocate: R_386_32 *0x%x += %p('%s')",
+ ptr, symval, Sym);
+ *ptr = (intptr_t)symval + addend;
+ break;
- // Relocation entries
- case DT_REL:
- dyntab[i].d_un.d_ptr += baseDiff;
- rel = (void *)dyntab[i].d_un.d_ptr;
- break;
- case DT_RELSZ:
- rel_count = dyntab[i].d_un.d_val / sizeof(Elf64_Rel);
- break;
- case DT_RELENT:
- if( dyntab[i].d_un.d_val != sizeof(Elf64_Rel) ) {
- SysDebug("ld-acess - Elf64Relocate: DT_RELENT(%i) != sizeof(Elf64_Rel)(%i)",
- dyntab[i].d_un.d_val, sizeof(Elf64_Rel));
- return NULL;
- }
- break;
- case DT_RELA:
- dyntab[i].d_un.d_ptr += baseDiff;
- rela = (void *)dyntab[i].d_un.d_ptr;
- break;
- case DT_RELASZ:
- rela_count = dyntab[i].d_un.d_val / sizeof(Elf64_Rela);
- break;
- case DT_RELAENT:
- if( dyntab[i].d_un.d_val != sizeof(Elf64_Rela) ) {
- SysDebug("ld-acess - Elf64Relocate: DT_RELAENT(%i) != sizeof(Elf64_Rela)(%i)",
- dyntab[i].d_un.d_val, sizeof(Elf64_Rela));
- return NULL;
- }
- break;
- case DT_JMPREL:
- dyntab[i].d_un.d_ptr += baseDiff;
- pltrel = (void *)dyntab[i].d_un.d_ptr;
- break;
- case DT_PLTREL:
- plt_type = dyntab[i].d_un.d_val;
- break;
- case DT_PLTRELSZ:
- plt_size = dyntab[i].d_un.d_val;
- break;
- }
- }
-
- // Relocation function
- void _Elf64DoReloc(Elf64_Xword r_info, void *ptr, Elf64_Sxword addend)
- {
- int sym = ELF64_R_SYM(r_info);
- int type = ELF64_R_TYPE(r_info);
- const char *symname = strtab + symtab[sym].st_name;
- switch( type )
- {
- case R_X86_64_NONE:
- break;
- case R_X86_64_64:
- *(uint64_t*)ptr = (uint64_t)GetSymbol(symname) + addend;
- break;
- default:
- SysDebug("ld-acess - _Elf64DoReloc: Unknown relocation type %i", type);
- break;
- }
- }
-
- if( rel )
- {
- DEBUGS("rel_count = %i", rel_count);
- for( i = 0; i < rel_count; i ++ )
- {
- uint64_t *ptr = (void *)( rel[i].r_offset + baseDiff );
- _Elf64DoReloc( rel[i].r_info, ptr, *ptr);
- }
- }
+ // 32 Bit Relocation wrt. Offset (S+A-P)
+ case R_386_PC32:
+ DEBUGS(" elf_doRelocate: '%s'", Sym);
+ if( !GetSymbol(Sym, &symval, NULL) ) return 1;
+ DEBUGS(" elf_doRelocate: R_386_PC32 *0x%x = 0x%x + 0x%p - 0x%x",
+ ptr, *ptr, symval, (intptr_t)ptr );
+ *ptr = (intptr_t)symval + addend - (intptr_t)ptr;
+ //*ptr = val + addend - ((Uint)ptr - iBaseDiff);
+ break;
+
+ // Absolute Value of a symbol (S)
+ case R_386_GLOB_DAT:
+ case R_386_JMP_SLOT:
+ DEBUGS(" elf_doRelocate: '%s'", Sym);
+ if( !GetSymbol(Sym, &symval, NULL) ) return 1;
+ DEBUGS(" elf_doRelocate: %s *0x%x = %p", csaR_NAMES[type], ptr, symval);
+ *ptr = (intptr_t)symval;
+ break;
+
+ // Base Address (B+A)
+ case R_386_RELATIVE:
+ DEBUGS(" elf_doRelocate: R_386_RELATIVE *0x%x = 0x%x + 0x%x", ptr, iBaseDiff, addend);
+ *ptr = iBaseDiff + addend;
+ break;
+
+ case R_386_COPY: {
+ size_t size;
+ if( !GetSymbol(Sym, &symval, &size) ) return 1;
+ DEBUGS(" elf_doRelocate_386: R_386_COPY (%p, %p, %i)", ptr, symval, size);
+ memcpy(ptr, symval, size);
+ break; }
- if( rela )
- {
- DEBUGS("rela_count = %i", rela_count);
- for( i = 0; i < rela_count; i ++ )
- {
- _Elf64DoReloc( rela[i].r_info, (void *)( rela[i].r_offset + baseDiff ), rela[i].r_addend );
- }
+ default:
+ SysDebug("elf_doRelocate_386: Unknown relocation %i", type);
+ return 2;
}
+ return 0;
+}
- if( pltrel && plt_type )
+int elf_doRelocate_arm(uint32_t r_info, uint32_t *ptr, Elf32_Addr addend, int type, int bRela, const char *Sym, intptr_t iBaseDiff)
+{
+ uint32_t val;
+ switch(type)
{
- if( plt_type == DT_REL ) {
- Elf64_Rel *plt = pltrel;
- int count = plt_size / sizeof(Elf64_Rel);
- DEBUGS("plt rel count = %i", count);
- for( i = 0; i < count; i ++ )
- {
- uint64_t *ptr = (void *)( plt[i].r_offset + baseDiff );
- _Elf64DoReloc( plt[i].r_info, ptr, *ptr);
- }
+ // (S + A) | T
+ case R_ARM_ABS32:
+ DEBUGS(" elf_doRelocate_arm: R_ARM_ABS32 %p (%s + %x)", ptr, Sym, addend);
+ if( !GetSymbol(Sym, (void**)&val, NULL) ) return 1;
+ *ptr = val + addend;
+ break;
+ case R_ARM_GLOB_DAT:
+ DEBUGS(" elf_doRelocate_arm: R_ARM_GLOB_DAT %p (%s + %x)", ptr, Sym, addend);
+ if( !GetSymbol(Sym, (void**)&val, NULL) ) return 1;
+ *ptr = val + addend;
+ break;
+ case R_ARM_JUMP_SLOT:
+ if(!bRela) addend = 0;
+ DEBUGS(" elf_doRelocate_arm: R_ARM_JUMP_SLOT %p (%s + %x)", ptr, Sym, addend);
+ if( !GetSymbol(Sym, (void**)&val, NULL) ) return 1;
+ *ptr = val + addend;
+ break;
+ // Copy
+ case R_ARM_COPY: {
+ size_t size;
+ void *src;
+ if( !GetSymbol(Sym, &src, &size) ) return 1;
+ DEBUGS(" elf_doRelocate_arm: R_ARM_COPY (%p, %p, %i)", ptr, src, size);
+ memcpy(ptr, src, size);
+ break; }
+ // Delta between link and runtime locations + A
+ case R_ARM_RELATIVE:
+ DEBUGS(" elf_doRelocate_arm: R_ARM_RELATIVE %p (0x%x + 0x%x)", ptr, iBaseDiff, addend);
+ if(Sym[0] != '\0') {
+ // TODO: Get delta for a symbol
+ SysDebug("elf_doRelocate_arm: TODO - Implment R_ARM_RELATIVE for symbols");
+ return 2;
}
else {
- Elf64_Rela *plt = pltrel;
- int count = plt_size / sizeof(Elf64_Rela);
- DEBUGS("plt rela count = %i", count);
- for( i = 0; i < count; i ++ )
- {
- _Elf64DoReloc( plt[i].r_info, (void *)(plt[i].r_offset + baseDiff), plt[i].r_addend);
- }
+ *ptr = iBaseDiff + addend;
}
+ break;
+ default:
+ SysDebug("elf_doRelocate_arm: Unknown Relocation, %i", type);
+ return 2;
}
+ return 0;
+}
- DEBUGS("Elf64Relocate: Relocations done, return %p", (void *)(hdr->e_entry + baseDiff));
- return (void *)(hdr->e_entry + baseDiff);
+int elf_doRelocate_unk(uint32_t r_info, uint32_t *ptr, Elf32_Addr addend, int type, int bRela, const char *Sym, intptr_t iBaseDiff)
+{
+ return 1;
}
void *Elf32Relocate(void *Base, char **envp, const char *Filename)
Elf32_Phdr *phtab;
int i, j; // Counters
char *libPath;
- Uint iRealBase = -1;
- Uint iBaseDiff;
+ intptr_t iRealBase = -1;
+ intptr_t iBaseDiff;
int iSegmentCount;
- int iSymCount;
+// int iSymCount;
Elf32_Rel *rel = NULL;
Elf32_Rela *rela = NULL;
- Uint32 *pltgot = NULL;
void *plt = NULL;
int relSz=0, relEntSz=8;
int relaSz=0, relaEntSz=8;
Elf32_Dyn *dynamicTab = NULL; // Dynamic Table Pointer
char *dynstrtab = NULL; // .dynamic String Table
Elf32_Sym *dynsymtab;
+ int (*do_relocate)(uint32_t t_info, uint32_t *ptr, Elf32_Addr addend, int Type, int bRela, const char *Sym, intptr_t iBaseDiff);
DEBUGS("ElfRelocate: (Base=0x%x)", Base);
// Parse Program Header to get Dynamic Table
- phtab = Base + hdr->phoff;
+ phtab = (void*)( (uintptr_t)Base + hdr->phoff );
iSegmentCount = hdr->phentcount;
for(i=0;i<iSegmentCount;i++)
{
// Adjust "Real" Base
iBaseDiff = (intptr_t)Base - iRealBase;
-
+
// hdr->entrypoint += iBaseDiff; // Adjust Entrypoint
// Check if a PT_DYNAMIC segement was found
if(!dynamicTab) {
SysDebug(" elf_relocate: No PT_DYNAMIC segment in image %p, returning", Base);
- return (void *)hdr->entrypoint + iBaseDiff;
+ return (void *)(intptr_t)(hdr->entrypoint + iBaseDiff);
}
-
+
+ // Allow writing to read-only segments, just in case they need to be relocated
+ // - Will be reversed at the end of the function
+ for( i = 0; i < iSegmentCount; i ++ )
+ {
+ if(phtab[i].Type == PT_LOAD && !(phtab[i].Flags & PF_W) ) {
+ uintptr_t addr = phtab[i].VAddr + iBaseDiff;
+ uintptr_t end = addr + phtab[i].MemSize;
+ for( ; addr < end; addr += PAGE_SIZE )
+ _SysSetMemFlags(addr, 0, 1); // Unset RO
+ }
+ }
+
// Adjust Dynamic Table
dynamicTab = (void *)( (intptr_t)dynamicTab + iBaseDiff );
// === Get Symbol table and String Table ===
+ dynsymtab = NULL;
for( j = 0; dynamicTab[j].d_tag != DT_NULL; j++)
{
switch(dynamicTab[j].d_tag)
DEBUGS(" elf_relocate: DYNAMIC Symbol Table 0x%x (0x%x)",
dynamicTab[j].d_val, dynamicTab[j].d_val + iBaseDiff);
if(iBaseDiff != 0) dynamicTab[j].d_val += iBaseDiff;
- dynsymtab = (void*)(dynamicTab[j].d_val);
-// hdr->misc.SymTable = dynamicTab[j].d_val; // Saved in unused bytes of ident
+ dynsymtab = (void*)(intptr_t)dynamicTab[j].d_val;
break;
// --- String Table ---
case DT_STRTAB:
DEBUGS(" elf_relocate: DYNAMIC String Table 0x%x (0x%x)",
dynamicTab[j].d_val, dynamicTab[j].d_val + iBaseDiff);
if(iBaseDiff != 0) dynamicTab[j].d_val += iBaseDiff;
- dynstrtab = (void*)(dynamicTab[j].d_val);
+ dynstrtab = (void*)(intptr_t)dynamicTab[j].d_val;
break;
// --- Hash Table --
case DT_HASH:
if(iBaseDiff != 0) dynamicTab[j].d_val += iBaseDiff;
- iSymCount = ((Uint*)(dynamicTab[j].d_val))[1];
-// hdr->misc.HashTable = dynamicTab[j].d_val; // Saved in unused bytes of ident
+// iSymCount = ((Elf32_Word*)(intptr_t)dynamicTab[j].d_val)[1];
break;
}
}
if(dynsymtab == NULL) {
SysDebug("ld-acess.so - WARNING: No Dynamic Symbol table in %p, returning", hdr);
- return (void *) hdr->entrypoint + iBaseDiff;
+ return (void *)(intptr_t) (hdr->entrypoint + iBaseDiff);
}
- #if 0
- // Alter Symbols to true base
- for(i=0;i<iSymCount;i++)
- {
- dynsymtab[i].value += iBaseDiff;
- dynsymtab[i].nameOfs += (intptr_t)dynstrtab;
- //DEBUGS("elf_relocate: Sym '%s' = 0x%x (relocated)", dynsymtab[i].name, dynsymtab[i].value);
- }
- #endif
-
// === Add to loaded list (can be imported now) ===
AddLoaded( Filename, Base );
#endif
return 0;
}
+ DEBUGS(" Lib loaded");
break;
// --- PLT/GOT ---
- case DT_PLTGOT: pltgot = (void*)(iBaseDiff + dynamicTab[j].d_val); break;
+// case DT_PLTGOT: pltgot = (void*)(iBaseDiff + dynamicTab[j].d_val); break;
case DT_JMPREL: plt = (void*)(iBaseDiff + dynamicTab[j].d_val); break;
case DT_PLTREL: pltType = dynamicTab[j].d_val; break;
case DT_PLTRELSZ: pltSz = dynamicTab[j].d_val; break;
}
DEBUGS(" elf_relocate: Beginning Relocation");
-
- void elf_doRelocate(Uint r_info, Uint32 *ptr, Uint32 addend, Elf32_Sym *symtab)
+
+ int fail = 0;
+
+ switch(hdr->machine)
{
- int type = ELF32_R_TYPE(r_info);
- int sym = ELF32_R_SYM(r_info);
- Uint32 val;
- const char *symname = dynstrtab + symtab[sym].nameOfs;
- switch( type )
- {
- // Standard 32 Bit Relocation (S+A)
- case R_386_32:
- val = (intptr_t) GetSymbol( symname );
- DEBUGS(" elf_doRelocate: R_386_32 *0x%x += 0x%x('%s')",
- ptr, val, symname);
- *ptr = val + addend;
- break;
-
- // 32 Bit Relocation wrt. Offset (S+A-P)
- case R_386_PC32:
- DEBUGS(" elf_doRelocate: #%i: '%s'", sym, symname);
- val = (intptr_t) GetSymbol( symname );
- DEBUGS(" elf_doRelocate: R_386_PC32 *0x%x = 0x%x + 0x%x - 0x%x",
- ptr, *ptr, val, (intptr_t)ptr );
- *ptr = val + addend - (intptr_t)ptr;
- //*ptr = val + addend - ((Uint)ptr - iBaseDiff);
- break;
-
- // Absolute Value of a symbol (S)
- case R_386_GLOB_DAT:
- case R_386_JMP_SLOT:
- DEBUGS(" elf_doRelocate: #%i: '%s'", sym, symname);
- val = (intptr_t) GetSymbol( symname );
- DEBUGS(" elf_doRelocate: %s *0x%x = 0x%x", csaR_NAMES[type], ptr, val);
- *ptr = val;
- break;
-
- // Base Address (B+A)
- case R_386_RELATIVE:
- DEBUGS(" elf_doRelocate: R_386_RELATIVE *0x%x = 0x%x + 0x%x", ptr, iBaseDiff, addend);
- *ptr = iBaseDiff + addend;
- break;
-
- default:
- DEBUGS(" elf_doRelocate: Rel 0x%x: 0x%x,%s", ptr, sym, csaR_NAMES[type]);
- break;
- }
+ case EM_386:
+ do_relocate = elf_doRelocate_386;
+ break;
+ case EM_ARM:
+ do_relocate = elf_doRelocate_arm;
+ break;
+ default:
+ SysDebug("Elf32Relocate: Unknown machine type %i", hdr->machine);
+ do_relocate = elf_doRelocate_unk;
+ fail = 1;
+ break;
}
+ DEBUGS("do_relocate = %p (%p or %p)", do_relocate, &elf_doRelocate_386, &elf_doRelocate_arm);
+
+ #define _doRelocate(r_info, ptr, bRela, addend) \
+ do_relocate(r_info, ptr, addend, ELF32_R_TYPE(r_info), bRela, \
+ dynstrtab + dynsymtab[ELF32_R_SYM(r_info)].nameOfs, iBaseDiff);
+
// Parse Relocation Entries
if(rel && relSz)
{
- Uint32 *ptr;
+ Elf32_Word *ptr;
DEBUGS(" elf_relocate: rel=0x%x, relSz=0x%x, relEntSz=0x%x", rel, relSz, relEntSz);
j = relSz / relEntSz;
for( i = 0; i < j; i++ )
{
//DEBUGS(" Rel %i: 0x%x+0x%x", i, iBaseDiff, rel[i].r_offset);
ptr = (void*)(iBaseDiff + rel[i].r_offset);
- elf_doRelocate(rel[i].r_info, ptr, *ptr, dynsymtab);
+ fail |= _doRelocate(rel[i].r_info, ptr, 0, *ptr);
}
}
// Parse Relocation Entries
if(rela && relaSz)
{
- Uint32 *ptr;
+ Elf32_Word *ptr;
DEBUGS(" elf_relocate: rela=0x%x, relaSz=0x%x, relaEntSz=0x%x", rela, relaSz, relaEntSz);
j = relaSz / relaEntSz;
for( i = 0; i < j; i++ )
{
ptr = (void*)(iBaseDiff + rela[i].r_offset);
- elf_doRelocate(rel[i].r_info, ptr, rela[i].r_addend, dynsymtab);
+ fail |= _doRelocate(rel[i].r_info, ptr, 1, rela[i].r_addend);
}
}
// === Process PLT (Procedure Linkage Table) ===
if(plt && pltSz)
{
- Uint32 *ptr;
+ Elf32_Word *ptr;
DEBUGS(" elf_relocate: Relocate PLT, plt=0x%x", plt);
if(pltType == DT_REL)
{
for(i=0;i<j;i++)
{
ptr = (void*)(iBaseDiff + pltRel[i].r_offset);
- elf_doRelocate(pltRel[i].r_info, ptr, *ptr, dynsymtab);
+ fail |= _doRelocate(pltRel[i].r_info, ptr, 0, *ptr);
}
}
else
for(i=0;i<j;i++)
{
ptr = (void*)(iRealBase + pltRela[i].r_offset);
- elf_doRelocate(pltRela[i].r_info, ptr, pltRela[i].r_addend, dynsymtab);
+ fail |= _doRelocate(pltRela[i].r_info, ptr, 1, pltRela[i].r_addend);
}
}
}
+
+ // Re-set readonly
+ for( i = 0; i < iSegmentCount; i ++ )
+ {
+ // If load and not writable
+ if(phtab[i].Type == PT_LOAD && !(phtab[i].Flags & PF_W) ) {
+ uintptr_t addr = phtab[i].VAddr + iBaseDiff;
+ uintptr_t end = addr + phtab[i].MemSize;
+ for( ; addr < end; addr += PAGE_SIZE )
+ _SysSetMemFlags(addr, 1, 1); // Unset RO
+ }
+ }
+
+ if( fail ) {
+ DEBUGS("ElfRelocate: Failure");
+ return NULL;
+ }
+
+ #undef _doRelocate
+
+ DEBUGS("ElfRelocate: RETURN 0x%x to %p", hdr->entrypoint + iBaseDiff, __builtin_return_address(0));
+ return (void*)(intptr_t)( hdr->entrypoint + iBaseDiff );
+}
+
+int Elf32GetSymbol(void *Base, const char *Name, void **ret, size_t *Size)
+{
+ Elf32_Ehdr *hdr = Base;
+ Elf32_Sym *symtab = NULL;
+ int nbuckets = 0;
+ Elf32_Word *pBuckets = NULL;
+ Elf32_Word *pChains;
+ uint32_t iNameHash;
+ const char *dynstrtab = NULL;
+ uintptr_t iBaseDiff = -1;
+ Elf32_Phdr *phtab;
+ Elf32_Dyn *dynTab = NULL;
+ int i;
+
+ // Locate the tables
+ phtab = (void*)( (uintptr_t)Base + hdr->phoff );
+ for( i = 0; i < hdr->phentcount; i ++ )
+ {
+ if(phtab[i].Type == PT_LOAD && iBaseDiff > phtab[i].VAddr)
+ iBaseDiff = phtab[i].VAddr;
+ if( phtab[i].Type == PT_DYNAMIC ) {
+ dynTab = (void*)(intptr_t)phtab[i].VAddr;
+ }
+ }
+ if( !dynTab ) {
+ SysDebug("ERROR - Unable to find DYNAMIC segment in %p", Base);
+ return 0;
+ }
+ iBaseDiff = (intptr_t)Base - iBaseDiff; // Make iBaseDiff actually the diff
+ dynTab = (void*)( (intptr_t)dynTab + iBaseDiff );
+ for( i = 0; dynTab[i].d_tag != DT_NULL; i++)
+ {
+ switch(dynTab[i].d_tag)
+ {
+ // --- Symbol Table ---
+ case DT_SYMTAB:
+ symtab = (void*)(intptr_t) dynTab[i].d_val; // Rebased in Relocate
+ break;
+ case DT_STRTAB:
+ dynstrtab = (void*)(intptr_t) dynTab[i].d_val;
+ break;
+ // --- Hash Table --
+ case DT_HASH:
+ pBuckets = (void*)(intptr_t) dynTab[i].d_val;
+ break;
+ }
+ }
+
+ if( !symtab ) {
+ SysDebug("ERRO - No DT_SYMTAB in %p", Base);
+ return 0;
+ }
+ if( !pBuckets ) {
+ SysDebug("ERRO - No DT_HASH in %p", Base);
+ return 0;
+ }
+ if( !dynstrtab ) {
+ SysDebug("ERRO - No DT_STRTAB in %p", Base);
+ return 0;
+ }
+
+ // ... ok... maybe they haven't been relocated
+ if( (uintptr_t)symtab < (uintptr_t)Base )
+ {
+ symtab = (void*)( (uintptr_t)symtab + iBaseDiff );
+ pBuckets = (void*)( (uintptr_t)pBuckets + iBaseDiff );
+ dynstrtab = (void*)( (uintptr_t)dynstrtab + iBaseDiff );
+ SysDebug("Executable not yet relocated");
+ }
+
+ nbuckets = pBuckets[0];
+// iSymCount = pBuckets[1];
+ pBuckets = &pBuckets[2];
+ pChains = &pBuckets[ nbuckets ];
+
+ // Get hash
+ iNameHash = ElfHashString(Name);
+ iNameHash %= nbuckets;
+
+ // Walk Chain
+ i = pBuckets[ iNameHash ];
+ if(symtab[i].shndx != SHN_UNDEF && strcmp(dynstrtab + symtab[i].nameOfs, Name) == 0) {
+ *ret = (void*)( (uintptr_t) symtab[ i ].value + iBaseDiff );
+ if(Size) *Size = symtab[i].size;
+ return 1;
+ }
+
+ while(pChains[i] != STN_UNDEF)
+ {
+ i = pChains[i];
+ if(symtab[i].shndx != SHN_UNDEF && strcmp(dynstrtab + symtab[ i ].nameOfs, Name) == 0) {
+ *ret = (void*)( (uintptr_t)symtab[ i ].value + iBaseDiff );
+ if(Size) *Size = symtab[i].size;
+ return 1;
+ }
+ }
- DEBUGS("ElfRelocate: RETURN 0x%x", hdr->entrypoint + iBaseDiff);
- return (void*)hdr->entrypoint + iBaseDiff;
+ return 0;
}
+#ifdef SUPPORT_ELF64
+void *Elf64Relocate(void *Base, char **envp, const char *Filename)
+{
+ int i;
+ Elf64_Ehdr *hdr = Base;
+ Elf64_Phdr *phtab;
+ Elf64_Dyn *dyntab = NULL;
+ Elf64_Addr compiledBase = -1, baseDiff;
+ Elf64_Sym *symtab = NULL;
+ char *strtab = NULL;
+ Elf64_Word *hashtab = NULL;
+ Elf64_Rel *rel = NULL;
+ int rel_count = 0;
+ Elf64_Rela *rela = NULL;
+ int rela_count = 0;
+ void *pltrel = NULL;
+ int plt_size = 0, plt_type = 0;
-/**
- * \fn int ElfGetSymbol(Uint Base, const char *name, void **ret)
- */
-int ElfGetSymbol(void *Base, const char *Name, void **ret)
+ DEBUGS("Elf64Relocate: hdr = {");
+ DEBUGS("Elf64Relocate: e_ident = '%.16s'", hdr->e_ident);
+ DEBUGS("Elf64Relocate: e_type = 0x%x", hdr->e_type);
+ DEBUGS("Elf64Relocate: e_machine = 0x%x", hdr->e_machine);
+ DEBUGS("Elf64Relocate: e_version = 0x%x", hdr->e_version);
+ DEBUGS("Elf64Relocate: e_entry = %p", hdr->e_entry);
+ DEBUGS("Elf64Relocate: e_phoff = 0x%llx", hdr->e_phoff);
+ DEBUGS("Elf64Relocate: e_shoff = 0x%llx", hdr->e_shoff);
+ DEBUGS("Elf64Relocate: e_flags = 0x%x", hdr->e_flags);
+ DEBUGS("Elf64Relocate: e_ehsize = 0x%x", hdr->e_ehsize);
+ DEBUGS("Elf64Relocate: e_phentsize = 0x%x", hdr->e_phentsize);
+ DEBUGS("Elf64Relocate: e_phnum = %i", hdr->e_phnum);
+
+ // Scan for the dynamic table (and find the compiled base)
+ phtab = (void*)((uintptr_t)Base + (uintptr_t)hdr->e_phoff);
+ for( i = 0; i < hdr->e_phnum; i ++ )
+ {
+ if(phtab[i].p_type == PT_DYNAMIC)
+ dyntab = (void *)(intptr_t)phtab[i].p_vaddr;
+ if(phtab[i].p_type == PT_LOAD && compiledBase > phtab[i].p_vaddr)
+ compiledBase = phtab[i].p_vaddr;
+ }
+
+ baseDiff = (uintptr_t)Base - compiledBase;
+
+ DEBUGS("baseDiff = %p", baseDiff);
+
+ if(dyntab == NULL) {
+ SysDebug(" Elf64Relocate: No PT_DYNAMIC segment in image %p, returning", Base);
+ return (void *)(uintptr_t)(hdr->e_entry + baseDiff);
+ }
+
+ dyntab = (void *)(uintptr_t)((uintptr_t)dyntab + baseDiff);
+
+ // Parse the dynamic table (first pass)
+ // - Search for String, Symbol and Hash tables
+ for(i = 0; dyntab[i].d_tag != DT_NULL; i ++)
+ {
+ switch(dyntab[i].d_tag)
+ {
+ case DT_SYMTAB:
+ dyntab[i].d_un.d_ptr += baseDiff;
+ symtab = (void *)(uintptr_t)dyntab[i].d_un.d_ptr;
+ break;
+ case DT_STRTAB:
+ dyntab[i].d_un.d_ptr += baseDiff;
+ strtab = (void *)(uintptr_t)dyntab[i].d_un.d_ptr;
+ break;
+ case DT_HASH:
+ dyntab[i].d_un.d_ptr += baseDiff;
+ hashtab = (void *)(uintptr_t)dyntab[i].d_un.d_ptr;
+ break;
+ }
+ }
+
+ if( !symtab || !strtab || !hashtab ) {
+ SysDebug("ld-acess - Elf64Relocate: Missing Symbol, string or hash table");
+ return NULL;
+ }
+
+ // Ready for symbol use
+ AddLoaded( Filename, Base );
+
+ // Second pass on dynamic table
+ for(i = 0; dyntab[i].d_tag != DT_NULL; i ++)
+ {
+ DEBUGS("dyntab[%i].d_tag = %i", i, dyntab[i].d_tag);
+ switch(dyntab[i].d_tag)
+ {
+ case DT_SONAME: break;
+
+ case DT_NEEDED: {
+ char *libPath = strtab + dyntab[i].d_un.d_val;
+ DEBUGS("Elf64Relocate: libPath = '%s'", libPath);
+ if(LoadLibrary(libPath, NULL, envp) == 0) {
+ SysDebug("ld-acess - Elf64Relocate: Unable to load '%s'", libPath);
+ return NULL;
+ }
+ } break;
+
+ // Relocation entries
+ case DT_REL:
+ dyntab[i].d_un.d_ptr += baseDiff;
+ rel = (void *)(uintptr_t)dyntab[i].d_un.d_ptr;
+ break;
+ case DT_RELSZ:
+ rel_count = dyntab[i].d_un.d_val / sizeof(Elf64_Rel);
+ break;
+ case DT_RELENT:
+ if( dyntab[i].d_un.d_val != sizeof(Elf64_Rel) ) {
+ SysDebug("ld-acess - Elf64Relocate: DT_RELENT(%i) != sizeof(Elf64_Rel)(%i)",
+ dyntab[i].d_un.d_val, sizeof(Elf64_Rel));
+ return NULL;
+ }
+ break;
+ case DT_RELA:
+ dyntab[i].d_un.d_ptr += baseDiff;
+ rela = (void *)(uintptr_t)dyntab[i].d_un.d_ptr;
+ break;
+ case DT_RELASZ:
+ rela_count = dyntab[i].d_un.d_val / sizeof(Elf64_Rela);
+ break;
+ case DT_RELAENT:
+ if( dyntab[i].d_un.d_val != sizeof(Elf64_Rela) ) {
+ SysDebug("ld-acess - Elf64Relocate: DT_RELAENT(%i) != sizeof(Elf64_Rela)(%i)",
+ dyntab[i].d_un.d_val, sizeof(Elf64_Rela));
+ return NULL;
+ }
+ break;
+ case DT_JMPREL:
+ dyntab[i].d_un.d_ptr += baseDiff;
+ pltrel = (void *)(uintptr_t)dyntab[i].d_un.d_ptr;
+ break;
+ case DT_PLTREL:
+ plt_type = dyntab[i].d_un.d_val;
+ break;
+ case DT_PLTRELSZ:
+ plt_size = dyntab[i].d_un.d_val;
+ break;
+ }
+ }
+
+ // Relocation function
+ auto int _Elf64DoReloc(Elf64_Xword r_info, void *ptr, Elf64_Sxword addend);
+ int _Elf64DoReloc(Elf64_Xword r_info, void *ptr, Elf64_Sxword addend)
+ {
+ int sym = ELF64_R_SYM(r_info);
+ int type = ELF64_R_TYPE(r_info);
+ const char *symname = strtab + symtab[sym].st_name;
+ void *symval;
+ //DEBUGS("_Elf64DoReloc: %s", symname);
+ switch( type )
+ {
+ case R_X86_64_NONE:
+ break;
+ case R_X86_64_64:
+ if( !GetSymbol(symname, &symval, NULL) ) return 1;
+ *(uint64_t*)ptr = (uintptr_t)symval + addend;
+ break;
+ case R_X86_64_COPY: {
+ size_t size;
+ if( !GetSymbol(symname, &symval, &size) ) return 1;
+ memcpy(ptr, symval, size);
+ } break;
+ case R_X86_64_GLOB_DAT:
+ if( !GetSymbol(symname, &symval, NULL) ) return 1;
+ *(uint64_t*)ptr = (uintptr_t)symval;
+ break;
+ case R_X86_64_JUMP_SLOT:
+ if( !GetSymbol(symname, &symval, NULL) ) return 1;
+ *(uint64_t*)ptr = (uintptr_t)symval;
+ break;
+ case R_X86_64_RELATIVE:
+ *(uint64_t*)ptr = (uintptr_t)Base + addend;
+ break;
+ default:
+ SysDebug("ld-acess - _Elf64DoReloc: Unknown relocation type %i", type);
+ return 2;
+ }
+ //DEBUGS("_Elf64DoReloc: - Good");
+ return 0;
+ }
+
+ int fail = 0;
+ if( rel )
+ {
+ DEBUGS("rel_count = %i", rel_count);
+ for( i = 0; i < rel_count; i ++ )
+ {
+ uint64_t *ptr = (void *)(uintptr_t)( rel[i].r_offset + baseDiff );
+ fail |= _Elf64DoReloc( rel[i].r_info, ptr, *ptr);
+ }
+ }
+
+ if( rela )
+ {
+ DEBUGS("rela_count = %i", rela_count);
+ for( i = 0; i < rela_count; i ++ )
+ {
+ uint64_t *ptr = (void *)(uintptr_t)( rela[i].r_offset + baseDiff );
+ fail |= _Elf64DoReloc( rela[i].r_info, ptr, rela[i].r_addend );
+ }
+ }
+
+ if( pltrel && plt_type )
+ {
+ if( plt_type == DT_REL ) {
+ Elf64_Rel *plt = pltrel;
+ int count = plt_size / sizeof(Elf64_Rel);
+ DEBUGS("plt rel count = %i", count);
+ for( i = 0; i < count; i ++ )
+ {
+ uint64_t *ptr = (void *)(uintptr_t)( plt[i].r_offset + baseDiff );
+ fail |= _Elf64DoReloc( plt[i].r_info, ptr, *ptr);
+ }
+ }
+ else {
+ Elf64_Rela *plt = pltrel;
+ int count = plt_size / sizeof(Elf64_Rela);
+ DEBUGS("plt rela count = %i", count);
+ for( i = 0; i < count; i ++ )
+ {
+ uint64_t *ptr = (void *)(uintptr_t)( plt[i].r_offset + baseDiff );
+ fail |= _Elf64DoReloc( plt[i].r_info, ptr, plt[i].r_addend);
+ }
+ }
+ }
+
+ if( fail ) {
+ DEBUGS("Elf64Relocate: Failure");
+ return NULL;
+ }
+
+ {
+ void *ret = (void *)(uintptr_t)(hdr->e_entry + baseDiff);
+ DEBUGS("Elf64Relocate: Relocations done, return %p", ret);
+ return ret;
+ }
+}
+
+int Elf64GetSymbol(void *Base, const char *Name, void **Ret, size_t *Size)
{
- Elf32_Ehdr *hdr = Base;
- Elf32_Sym *symtab;
+ Elf64_Ehdr *hdr = Base;
+ Elf64_Sym *symtab;
int nbuckets = 0;
- int iSymCount = 0;
+// int iSymCount = 0;
int i;
- Uint32 *pBuckets;
- Uint32 *pChains;
- Uint iNameHash;
+ Elf64_Word *pBuckets;
+ Elf64_Word *pChains;
+ uint32_t iNameHash;
const char *dynstrtab;
uintptr_t iBaseDiff = -1;
- //DEBUGS("ElfGetSymbol: (Base=0x%x, Name='%s')", Base, Name);
- #if 0
- pBuckets = (void *) (intptr_t) hdr->misc.HashTable;
- symtab = (void *) (intptr_t) hdr->misc.SymTable;
- dynstrtab = (void *) (intptr_t) hdr->misc.StrTab;
- #else
dynstrtab = NULL;
pBuckets = NULL;
symtab = NULL;
- #endif
// Catch the current executable
if( !pBuckets )
{
- Elf32_Phdr *phtab;
- Elf32_Dyn *dynTab = NULL;
+ Elf64_Phdr *phtab;
+ Elf64_Dyn *dynTab = NULL;
int j;
// Locate the tables
- phtab = (void*)( Base + hdr->phoff );
- for( i = 0; i < hdr->phentcount; i ++ )
+ phtab = (void*)( (intptr_t)Base + (uintptr_t)hdr->e_phoff );
+ for( i = 0; i < hdr->e_phnum; i ++ )
{
- if(phtab[i].Type == PT_LOAD && iBaseDiff > phtab[i].VAddr)
- iBaseDiff = phtab[i].VAddr;
- if( phtab[i].Type == PT_DYNAMIC ) {
- dynTab = (void*)(intptr_t)phtab[i].VAddr;
+ if(phtab[i].p_type == PT_LOAD && iBaseDiff > phtab[i].p_vaddr)
+ iBaseDiff = phtab[i].p_vaddr;
+ if( phtab[i].p_type == PT_DYNAMIC ) {
+ dynTab = (void*)(intptr_t)phtab[i].p_vaddr;
}
}
if( !dynTab ) {
- SysDebug("ERROR - Unable to find DYNAMIC segment in %p");
+ SysDebug("ERROR - Unable to find DYNAMIC segment in %p", Base);
return 0;
}
iBaseDiff = (intptr_t)Base - iBaseDiff; // Make iBaseDiff actually the diff
{
// --- Symbol Table ---
case DT_SYMTAB:
- symtab = (void*)(intptr_t) dynTab[j].d_val; // Rebased in Relocate
+ symtab = (void*)(intptr_t) dynTab[j].d_un.d_val; // Rebased in Relocate
break;
case DT_STRTAB:
- dynstrtab = (void*)(intptr_t) dynTab[j].d_val;
+ dynstrtab = (void*)(intptr_t) dynTab[j].d_un.d_val;
break;
// --- Hash Table --
case DT_HASH:
- pBuckets = (void*)(intptr_t) dynTab[j].d_val;
+ pBuckets = (void*)(intptr_t) dynTab[j].d_un.d_val;
break;
}
}
-
- #if 0
- hdr->misc.HashTable = pBucktets;
- hdr->misc.SymTable = symtab;
- hdr->misc.StrTab = dynstrtab;
- #endif
}
nbuckets = pBuckets[0];
- iSymCount = pBuckets[1];
+// iSymCount = pBuckets[1];
pBuckets = &pBuckets[2];
pChains = &pBuckets[ nbuckets ];
// Get hash
iNameHash = ElfHashString(Name);
iNameHash %= nbuckets;
- //DEBUGS(" ElfGetSymbol: iNameHash = 0x%x", iNameHash);
// Walk Chain
i = pBuckets[ iNameHash ];
- //DEBUGS(" ElfGetSymbol: strcmp(Name, \"%s\")", symtab[i].name);
- if(symtab[i].shndx != SHN_UNDEF && strcmp(dynstrtab + symtab[i].nameOfs, Name) == 0) {
- *ret = (void*) (intptr_t) symtab[ i ].value + iBaseDiff;
+ if(symtab[i].st_shndx != SHN_UNDEF && strcmp(dynstrtab + symtab[i].st_name, Name) == 0) {
+ *Ret = (void*)( (intptr_t)symtab[i].st_value + iBaseDiff );
+ if(Size) *Size = symtab[i].st_size;
+ DEBUGS("%s = %p", Name, *Ret);
return 1;
}
- //DEBUGS(" ElfGetSymbol: Hash of first = 0x%x", ElfHashString( symtab[i].name ) % nbuckets);
while(pChains[i] != STN_UNDEF)
{
- //DEBUGS(" pChains[%i] = %i", i, pChains[i]);
i = pChains[i];
- //DEBUGS(" ElfGetSymbol: strcmp(Name, \"%s\")", symtab[ i ].name);
- if(symtab[i].shndx != SHN_UNDEF && strcmp(dynstrtab + symtab[ i ].nameOfs, Name) == 0) {
- //DEBUGS("ElfGetSymbol: RETURN 1, '%s' = 0x%x", symtab[ i ].name, symtab[ i ].value);
- *ret = (void*)(intptr_t)symtab[ i ].value + iBaseDiff;
+ if(symtab[i].st_shndx != SHN_UNDEF && strcmp(dynstrtab + symtab[i].st_name, Name) == 0) {
+ *Ret = (void*)((intptr_t)symtab[i].st_value + iBaseDiff);
+ if(Size) *Size = symtab[i].st_size;
+ DEBUGS("%s = %p", Name, *Ret);
return 1;
}
}
- //DEBUGS("ElfGetSymbol: RETURN 0, Symbol '%s' not found", Name);
return 0;
}
+#endif
-Uint32 ElfHashString(const char *name)
+
+uint32_t ElfHashString(const char *name)
{
- Uint32 h = 0, g;
+ uint32_t h = 0, g;
while(*name)
{
- h = (h << 4) + *(Uint8*)name++;
+ h = (h << 4) + *(uint8_t*)name++;
if( (g = h & 0xf0000000) )
h ^= g >> 24;
h &= ~g;
return h;
}
-#if 0
-unsigned long elf_hash(const unsigned char *name)
-{
- unsigned long h = 0, g;
- while (*name)
- {
- h = (h << 4) + *name++;
- if (g = h & 0xf0000000)
- h ^= g >> 24;
- h &= ~g;
- }
- return h;
-}
-#endif