/*
- * 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 <assert.h>
#include "elf32.h"
-
-#define DEBUG 0
+#include "elf64.h"
#if DEBUG
-# define DEBUGS(v...) SysDebug(v)
+# 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"};
#endif
// === PROTOTYPES ===
-void elf_doRelocate(Uint r_info, Uint32 *ptr, Uint32 addend, Elf32_Sym *symtab, Uint base);
-Uint ElfHashString(char *name);
+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
+int _Elf64DoReloc_X86_64(void *Base, const char *strtab, Elf64_Sym *symtab, Elf64_Xword r_info, void *ptr, Elf64_Sxword addend);
+void *Elf64Relocate(void *Base, char **envp, const char *Filename);
+ int Elf64GetSymbol(void *Base, const char *Name, void **Ret, size_t *Size);
+#endif
+uint32_t ElfHashString(const char *name);
// === CODE ===
/**
- \fn int ElfRelocate(void *Base, char **envp, char *Filename)
- \brief Relocates a loaded ELF Executable
-*/
-void *ElfRelocate(void *Base, char **envp, char *Filename)
+ * \fn int ElfRelocate(void *Base, char **envp, const char *Filename)
+ * \brief Relocates a loaded ELF Executable
+ */
+void *ElfRelocate(void *Base, char **envp, const char *Filename)
+{
+ Elf32_Ehdr *hdr = Base;
+
+ switch(hdr->e_ident[4])
+ {
+ 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;
+ }
+}
+
+/**
+ * \fn int ElfGetSymbol(Uint Base, const char *name, void **ret)
+ */
+int ElfGetSymbol(void *Base, const char *Name, void **ret, size_t *Size)
+{
+ Elf32_Ehdr *hdr = Base;
+
+ switch(hdr->e_ident[4])
+ {
+ 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;
+ }
+}
+
+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 )
+ {
+ // 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;
+
+ // 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; }
+
+ default:
+ SysDebug("elf_doRelocate_386: Unknown relocation %i", type);
+ return 2;
+ }
+ return 0;
+}
+
+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)
+ {
+ // (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 {
+ *ptr = iBaseDiff + addend;
+ }
+ break;
+ default:
+ SysDebug("elf_doRelocate_arm: Unknown Relocation, %i", type);
+ return 2;
+ }
+ return 0;
+}
+
+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_Ehdr *hdr = Base;
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;
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)\n", Base);
+ DEBUGS("ElfRelocate: (Base=0x%x)", Base);
// Check magic header
// 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++)
+ for(int i = 0; i < iSegmentCount; i ++)
{
- // Determine linked base address
- if(phtab[i].Type == PT_LOAD && iRealBase > phtab[i].VAddr)
- iRealBase = phtab[i].VAddr;
-
- // Find Dynamic Section
- if(phtab[i].Type == PT_DYNAMIC) {
- if(dynamicTab) {
- DEBUGS(" WARNING - elf_relocate: Multiple PT_DYNAMIC segments\n");
- continue;
+ switch(phtab[i].Type)
+ {
+ case PT_LOAD:
+ // Determine linked base address
+ if( iRealBase > phtab[i].VAddr)
+ iRealBase = phtab[i].VAddr;
+ break;
+ case PT_DYNAMIC:
+ // Find Dynamic Section
+ if(!dynamicTab) {
+ dynamicTab = (void *) (intptr_t) phtab[i].VAddr;
+ }
+ else {
+ DEBUGS(" WARNING - elf_relocate: Multiple PT_DYNAMIC segments");
}
- dynamicTab = (void *) (intptr_t) phtab[i].VAddr;
- j = i; // Save Dynamic Table ID
+ break;
}
}
// Page Align real base
iRealBase &= ~0xFFF;
- DEBUGS(" elf_relocate: True Base = 0x%x, Compiled Base = 0x%x\n", Base, iRealBase);
+ DEBUGS(" elf_relocate: True Base = 0x%x, Compiled Base = 0x%x", Base, iRealBase);
// Adjust "Real" Base
iBaseDiff = (intptr_t)Base - iRealBase;
-
- hdr->entrypoint += iBaseDiff; // Adjust Entrypoint
+
+// hdr->entrypoint += iBaseDiff; // Adjust Entrypoint
// Check if a PT_DYNAMIC segement was found
if(!dynamicTab) {
- SysDebug(" elf_relocate: No PT_DYNAMIC segment in image, returning\n");
- return (void *)hdr->entrypoint;
+ SysDebug(" elf_relocate: No PT_DYNAMIC segment in image %p, returning", Base);
+ 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( int 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 ===
- for( j = 0; dynamicTab[j].d_tag != DT_NULL; j++)
+ dynsymtab = NULL;
+ for( int j = 0; dynamicTab[j].d_tag != DT_NULL; j++)
{
switch(dynamicTab[j].d_tag)
{
// --- Symbol Table ---
case DT_SYMTAB:
- DEBUGS(" elf_relocate: DYNAMIC Symbol Table 0x%x (0x%x)\n",
+ DEBUGS(" elf_relocate: DYNAMIC Symbol Table 0x%x (0x%x)",
dynamicTab[j].d_val, dynamicTab[j].d_val + iBaseDiff);
- 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 + iBaseDiff);
+ //if(iBaseDiff != 0) dynamicTab[j].d_val += iBaseDiff;
break;
// --- String Table ---
case DT_STRTAB:
- DEBUGS(" elf_relocate: DYNAMIC String Table 0x%x (0x%x)\n",
+ DEBUGS(" elf_relocate: DYNAMIC String Table 0x%x (0x%x)",
dynamicTab[j].d_val, dynamicTab[j].d_val + iBaseDiff);
- dynamicTab[j].d_val += iBaseDiff;
- dynstrtab = (void*)(dynamicTab[j].d_val);
+ dynstrtab = (void*)((intptr_t)dynamicTab[j].d_val + iBaseDiff);
+ //if(iBaseDiff != 0) dynamicTab[j].d_val += iBaseDiff;
break;
// --- Hash Table --
case DT_HASH:
- 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
+ //if(iBaseDiff != 0) dynamicTab[j].d_val += iBaseDiff;
+// iSymCount = ((Elf32_Word*)(intptr_t)dynamicTab[j].d_val)[1];
break;
}
}
if(dynsymtab == NULL) {
- SysDebug("ld-acess.so - WARNING: No Dynamic Symbol table, returning\n");
- return (void *) hdr->entrypoint;
+ SysDebug("ld-acess.so - WARNING: No Dynamic Symbol table in %p, returning", hdr);
+ return (void *)(intptr_t) (hdr->entrypoint + iBaseDiff);
}
-
- // 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)\n", dynsymtab[i].name, dynsymtab[i].value);
- }
-
+
// === Add to loaded list (can be imported now) ===
AddLoaded( Filename, Base );
// === Parse Relocation Data ===
- DEBUGS(" elf_relocate: dynamicTab = 0x%x\n", dynamicTab);
- for( j = 0; dynamicTab[j].d_tag != DT_NULL; j++)
+ DEBUGS(" elf_relocate: dynamicTab = 0x%x", dynamicTab);
+ for( int j = 0; dynamicTab[j].d_tag != DT_NULL; j++)
{
switch(dynamicTab[j].d_tag)
{
// --- Shared Library Name ---
case DT_SONAME:
- DEBUGS(" elf_relocate: .so Name '%s'\n", dynstrtab+dynamicTab[j].d_val);
+ DEBUGS(" elf_relocate: .so Name '%s'", dynstrtab+dynamicTab[j].d_val);
break;
// --- Needed Library ---
case DT_NEEDED:
libPath = dynstrtab + dynamicTab[j].d_val;
- DEBUGS(" Required Library '%s'\n", libPath);
+ DEBUGS(" dynstrtab = %p, d_val = 0x%x", dynstrtab, dynamicTab[j].d_val);
+ DEBUGS(" Required Library '%s'", libPath);
if(LoadLibrary(libPath, NULL, envp) == 0) {
#if DEBUG
- DEBUGS(" elf_relocate: Unable to load '%s'\n", libPath);
+ DEBUGS(" elf_relocate: Unable to load '%s'", libPath);
#else
- SysDebug("Unable to load required library '%s'\n", libPath);
+ SysDebug("Unable to load required library '%s'", libPath);
#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;
// --- Unknown ---
default:
if(dynamicTab[j].d_tag > DT_JMPREL) continue;
- //DEBUGS(" elf_relocate: %i-%i = %s,0x%x\n",
+ //DEBUGS(" elf_relocate: %i-%i = %s,0x%x",
// i,j, csaDT_NAMES[dynamicTab[j].d_tag],dynamicTab[j].d_val);
break;
}
}
- DEBUGS(" elf_relocate: Beginning Relocation\n");
+ DEBUGS(" elf_relocate: Beginning Relocation");
+
+ int fail = 0;
+
+ switch(hdr->machine)
+ {
+ 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;
- DEBUGS(" elf_relocate: rel=0x%x, relSz=0x%x, relEntSz=0x%x\n", rel, relSz, relEntSz);
- j = relSz / relEntSz;
- for( i = 0; i < j; i++ )
+ Elf32_Word *ptr;
+ DEBUGS(" elf_relocate: rel=0x%x, relSz=0x%x, relEntSz=0x%x", rel, relSz, relEntSz);
+ int max = relSz / relEntSz;
+ for( int i = 0; i < max; i++ )
{
- //DEBUGS(" Rel %i: 0x%x+0x%x\n", i, iBaseDiff, rel[i].r_offset);
+ //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, iBaseDiff);
+ fail |= _doRelocate(rel[i].r_info, ptr, 0, *ptr);
}
}
// Parse Relocation Entries
if(rela && relaSz)
{
- Uint32 *ptr;
- DEBUGS(" elf_relocate: rela=0x%x, relaSz=0x%x, relaEntSz=0x%x\n", rela, relaSz, relaEntSz);
- j = relaSz / relaEntSz;
- for( i = 0; i < j; i++ )
+ Elf32_Word *ptr;
+ DEBUGS(" elf_relocate: rela=0x%x, relaSz=0x%x, relaEntSz=0x%x", rela, relaSz, relaEntSz);
+ int count = relaSz / relaEntSz;
+ for( int i = 0; i < count; i++ )
{
ptr = (void*)(iBaseDiff + rela[i].r_offset);
- elf_doRelocate(rel[i].r_info, ptr, rela[i].r_addend, dynsymtab, iBaseDiff);
+ fail |= _doRelocate(rel[i].r_info, ptr, 1, rela[i].r_addend);
}
}
// === Process PLT (Procedure Linkage Table) ===
if(plt && pltSz)
{
- Uint32 *ptr;
- DEBUGS(" elf_relocate: Relocate PLT, plt=0x%x\n", plt);
+ Elf32_Word *ptr;
+ DEBUGS(" elf_relocate: Relocate PLT, plt=0x%x", plt);
if(pltType == DT_REL)
{
Elf32_Rel *pltRel = plt;
- j = pltSz / sizeof(Elf32_Rel);
- DEBUGS(" elf_relocate: PLT Reloc Type = Rel, %i entries\n", j);
- for(i=0;i<j;i++)
+ int count = pltSz / sizeof(Elf32_Rel);
+ DEBUGS(" elf_relocate: PLT Reloc Type = Rel, %i entries", count);
+ for(int i = 0; i < count; i ++)
{
ptr = (void*)(iBaseDiff + pltRel[i].r_offset);
- elf_doRelocate(pltRel[i].r_info, ptr, *ptr, dynsymtab, iRealBase);
+ fail |= _doRelocate(pltRel[i].r_info, ptr, 0, *ptr);
}
}
else
{
Elf32_Rela *pltRela = plt;
- j = pltSz / sizeof(Elf32_Rela);
- DEBUGS(" elf_relocate: PLT Reloc Type = Rela, %i entries\n", j);
- for(i=0;i<j;i++)
+ int count = pltSz / sizeof(Elf32_Rela);
+ DEBUGS(" elf_relocate: PLT Reloc Type = Rela, %i entries", count);
+ for(int i=0;i<count;i++)
{
ptr = (void*)(iRealBase + pltRela[i].r_offset);
- elf_doRelocate(pltRela[i].r_info, ptr, pltRela[i].r_addend, dynsymtab, iRealBase);
+ fail |= _doRelocate(pltRela[i].r_info, ptr, 1, pltRela[i].r_addend);
}
}
}
+
+ // Re-set readonly
+ for( int 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;
+
+ // Locate the tables
+ phtab = (void*)( (uintptr_t)Base + hdr->phoff );
+ for( int 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( int 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 + iBaseDiff); // Rebased in Relocate
+ break;
+ case DT_STRTAB:
+ dynstrtab = (void*)((intptr_t)dynTab[i].d_val + iBaseDiff);
+ break;
+ // --- Hash Table --
+ case DT_HASH:
+ pBuckets = (void*)((intptr_t)dynTab[i].d_val + iBaseDiff);
+ 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 ];
+ assert(pChains);
+
+ // Get hash
+ iNameHash = ElfHashString(Name);
+ iNameHash %= nbuckets;
+
+ // Walk Chain
+ int idx = pBuckets[ iNameHash ];
+ do {
+ Elf32_Sym *sym = &symtab[idx];
+ assert(sym);
+ if(sym->shndx != SHN_UNDEF && strcmp(dynstrtab + sym->nameOfs, Name) == 0) {
+ *ret = (void*)( (uintptr_t)sym->value + iBaseDiff );
+ if(Size) *Size = sym->size;
+ return 1;
+ }
+ } while( (idx = pChains[idx]) != STN_UNDEF && idx != pBuckets[iNameHash] );
- DEBUGS("ElfRelocate: RETURN 0x%x", hdr->entrypoint);
- return (void*)hdr->entrypoint;
+ return 0;
}
-void elf_doRelocate(Uint r_info, Uint32 *ptr, Uint32 addend, Elf32_Sym *symtab, Uint base)
+#ifdef SUPPORT_ELF64
+typedef int (*t_elf64_doreloc)(void *Base, const char *strtab, Elf64_Sym *symtab, Elf64_Xword r_info, void *ptr, Elf64_Sxword addend);
+
+int _Elf64DoReloc_X86_64(void *Base, const char *strtab, Elf64_Sym *symtab, Elf64_Xword r_info, void *ptr, Elf64_Sxword addend)
{
- int type = ELF32_R_TYPE(r_info);
- int sym = ELF32_R_SYM(r_info);
- Uint32 val;
+ 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 )
{
- // Standard 32 Bit Relocation (S+A)
- case R_386_32:
- val = (intptr_t) GetSymbol( symtab[sym].name );
- DEBUGS(" elf_doRelocate: R_386_32 *0x%x += 0x%x('%s')\n",
- ptr, val, symtab[sym].name);
- *ptr = val + addend;
+ case R_X86_64_NONE:
break;
-
- // 32 Bit Relocation wrt. Offset (S+A-P)
- case R_386_PC32:
- DEBUGS(" elf_doRelocate: #%i: '%s'\n", sym, symtab[sym].name);
- val = (intptr_t) GetSymbol( symtab[sym].name );
- DEBUGS(" elf_doRelocate: R_386_PC32 *0x%x = 0x%x + 0x%x - 0x%x\n",
- ptr, *ptr, val, (Uint)ptr );
- *ptr = val + addend - (intptr_t)ptr;
- //*ptr = val + addend - ((Uint)ptr - base);
+ case R_X86_64_64:
+ if( !GetSymbol(symname, &symval, NULL) ) return 1;
+ *(uint64_t*)ptr = (uintptr_t)symval + addend;
break;
-
- // Absolute Value of a symbol (S)
- case R_386_GLOB_DAT:
- case R_386_JMP_SLOT:
- DEBUGS(" elf_doRelocate: #%i: '%s'\n", sym, symtab[sym].name);
- val = (intptr_t) GetSymbol( symtab[sym].name );
- DEBUGS(" elf_doRelocate: %s *0x%x = 0x%x\n", csaR_NAMES[type], ptr, val);
- *ptr = val;
+ 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;
-
- // Base Address (B+A)
- case R_386_RELATIVE:
- DEBUGS(" elf_doRelocate: R_386_RELATIVE *0x%x = 0x%x + 0x%x\n", ptr, base, addend);
- *ptr = base + addend;
+ case R_X86_64_JUMP_SLOT:
+ if( !GetSymbol(symname, &symval, NULL) ) return 1;
+ *(uint64_t*)ptr = (uintptr_t)symval;
break;
-
- default:
- DEBUGS(" elf_doRelocate: Rel 0x%x: 0x%x,%s\n", ptr, sym, csaR_NAMES[type]);
+ 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;
}
-/**
- * \fn int ElfGetSymbol(Uint Base, char *name, void **ret)
- */
-int ElfGetSymbol(void *Base, char *Name, void **ret)
+void *Elf64Relocate(void *Base, char **envp, const char *Filename)
{
- Elf32_Ehdr *hdr = Base;
- Elf32_Sym *symtab;
+ 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;
+
+ 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
+ t_elf64_doreloc fpElf64DoReloc = &_Elf64DoReloc_X86_64;
+ #define _Elf64DoReloc(info, ptr, addend) fpElf64DoReloc(Base, strtab, symtab, info, ptr, addend)
+
+ 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)
+{
+ Elf64_Ehdr *hdr = Base;
+ Elf64_Sym *symtab;
int nbuckets = 0;
- int iSymCount = 0;
+// int iSymCount = 0;
int i;
- Uint *pBuckets;
- Uint *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')\n", Base, Name);
+ dynstrtab = NULL;
+ pBuckets = NULL;
+ symtab = NULL;
// Catch the current executable
- #if 0
- if( !hdr->misc.HashTable )
+ 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_DYNAMIC ) {
- dynTab = (void*)phtab[i].VAddr;
- break ;
+ 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", (void*)Base);
+ 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( j = 0; dynTab[j].d_tag != DT_NULL; j++)
{
{
// --- Symbol Table ---
case DT_SYMTAB:
- hdr->misc.SymTable = dynTab[j].d_val;
+ symtab = (void*)(intptr_t) dynTab[j].d_un.d_val; // Rebased in Relocate
+ break;
+ case DT_STRTAB:
+ dynstrtab = (void*)(intptr_t) dynTab[j].d_un.d_val;
break;
// --- Hash Table --
case DT_HASH:
- hdr->misc.HashTable = dynTab[j].d_val;
+ pBuckets = (void*)(intptr_t) dynTab[j].d_un.d_val;
break;
}
}
}
- #endif
-
- if( !hdr->misc.SymTable || !hdr->misc.HashTable ) {
- return 0;
- }
- pBuckets = (void *) (intptr_t) hdr->misc.HashTable;
- symtab = (void *) (intptr_t) hdr->misc.SymTable;
-
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\n", iNameHash);
// Walk Chain
i = pBuckets[ iNameHash ];
- //DEBUGS(" ElfGetSymbol: strcmp(Name, \"%s\")\n", symtab[i].name);
- if(symtab[i].shndx != SHN_UNDEF && strcmp(symtab[i].name, Name) == 0) {
- *ret = (void*) (intptr_t) symtab[ i ].value;
+ 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\n", ElfHashString( symtab[i].name ) % nbuckets);
while(pChains[i] != STN_UNDEF)
{
- //DEBUGS(" pChains[%i] = %i\n", i, pChains[i]);
i = pChains[i];
- //DEBUGS(" ElfGetSymbol: strcmp(Name, \"%s\")\n", symtab[ i ].name);
- if(symtab[i].shndx != SHN_UNDEF && strcmp(symtab[ i ].name, Name) == 0) {
- //DEBUGS("ElfGetSymbol: RETURN 1, '%s' = 0x%x\n", symtab[ i ].name, symtab[ i ].value);
- *ret = (void*)(intptr_t)symtab[ i ].value;
+ 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\n", Name);
return 0;
}
+#endif
+
-Uint ElfHashString(char *name)
+uint32_t ElfHashString(const char *name)
{
- Uint h = 0, g;
+ uint32_t h = 0, g;
while(*name)
{
- h = (h << 4) + *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
git.ucc.asn.au / tpg / acess2.git / blobdiff
UCC git Repository :: git.ucc.asn.au