*
* elf.c
* - ELF32/ELF64 relocation
+ *
+ * TODO: Have GetSymbol() return a symbol "strength" on success. Allows STB_WEAK to be overriden by STB_GLOBAL
*/
-#ifndef DEBUG // This code is #include'd from the kernel, so DEBUG may already be defined
+#ifndef KERNEL_VERSION
# define DEBUG 0
#endif
#define WARNING(f,...) SysDebug("WARN: "f ,## __VA_ARGS__) // Malformed file
#define NOTICE(f,...) SysDebug("NOTICE: "f ,## __VA_ARGS__) // Missing relocation
-#define TRACE(f,...) DEBUG_OUT("TRACE:%s:%i "f, __func__, __LINE__ ,## __VA_ARGS__) // Debugging trace
+//#define TRACE(f,...) DEBUG_OUT("TRACE:%s:%i "f, __func__, __LINE__ ,## __VA_ARGS__) // Debugging trace
+#define TRACE(f,...) DEBUG_OUT("TRACE:%s "f, __func__,## __VA_ARGS__) // Debugging trace
#ifndef DISABLE_ELF64
# define SUPPORT_ELF64
case R_386_COPY: {
void *old_symval = symval;
GetSymbol(Info->strtab + sym->st_name, &symval, &size, Info->Base);
- if( symval == old_symval ) {
- WARNING("Can't find required external symbol '%s'", Info->strtab + sym->st_name);
- return 1;
+ if( symval == old_symval )
+ {
+ if( ELF32_ST_BIND(sym->st_info) != STB_WEAK )
+ {
+ WARNING("sym={val:%p,size:0x%x,info:0x%x,other:0x%x,shndx:%i}",
+ sym->st_value, sym->st_size, sym->st_info, sym->st_other, sym->st_shndx);
+ WARNING("Can't find required external symbol '%s' for R_386_COPY", Info->strtab + sym->st_name);
+ return 1;
+ }
+ // Don't bother doing the memcpy
+ TRACE("R_386_COPY (%p, %p, %i)", ptr, symval, size);
+ }
+ else
+ {
+ TRACE("R_386_COPY (%p, %p, %i)", ptr, symval, size);
+ memcpy(ptr, symval, size);
}
- TRACE("R_386_COPY (%p, %p, %i)", ptr, symval, size);
- memcpy(ptr, symval, size);
break; }
default:
const Elf32_Ehdr *hdr = Base;
char *libPath;
intptr_t iRealBase = -1;
- intptr_t iBaseDiff;
Elf32_Rel *rel = NULL;
Elf32_Rela *rela = NULL;
void *plt = NULL;
// Page Align real base
iRealBase &= ~0xFFF;
- TRACE("True Base = 0x%x, Compiled Base = 0x%x", Base, iRealBase);
// Adjust "Real" Base
- iBaseDiff = (intptr_t)Base - iRealBase;
+ const intptr_t iBaseDiff = (intptr_t)Base - iRealBase;
+
+ TRACE("True Base = 0x%x, Compiled Base = 0x%x, Difference = 0x%x", Base, iRealBase, iBaseDiff);
// Check if a PT_DYNAMIC segement was found
if(!dynamicTab) {
}
else
{
- // TODO: What about weak locally-defined symbols?
- if( ELF32_ST_BIND(sym->st_info) == STB_WEAK )
+ void *newval;
+ size_t newsize;
+ if( ELF32_ST_BIND(sym->st_info) != STB_WEAK )
+ {
+ TRACE("Sym %i'%s' = %p (local)", i, name, sym->st_value + iBaseDiff);
+ sym->st_value += iBaseDiff;
+ }
+ // If GetSymbol doesn't return a strong/global symbol value
+ else if( GetSymbol(name, &newval, &newsize, Base) != 1 )
{
- WARNING("TODO: Weak bound local symbols '%s'", name);
- //assert(ELF32_ST_BIND(sym->st_info) != STB_WEAK);
- //return NULL;
+ TRACE("Sym %i'%s' = %p (Local weak)", i, name, sym->st_value + iBaseDiff);
+ sym->st_value += iBaseDiff;
+ }
+ else
+ {
+ TRACE("Sym %i'%s' = %p+0x%x (Extern weak)", i, name, newval, newsize);
+ sym->st_value = (uintptr_t)newval;
+ sym->st_size = newsize;
}
- TRACE("Sym %i'%s' %p += 0x%x", i, name, sym->st_value, iBaseDiff);
- sym->st_value += iBaseDiff;
}
}
int Elf32GetSymbol(void *Base, const char *Name, void **ret, size_t *Size)
{
- int section;
+ int section, binding;
TRACE("Elf32GetSymbol(%p,%s,...)", Base, Name);
- if( Elf32GetSymbolInfo(Base, Name, ret, Size, §ion, NULL, NULL) )
+ if( Elf32GetSymbolInfo(Base, Name, ret, Size, §ion, &binding, NULL) )
return 0;
if( section == SHN_UNDEF ) {
- TRACE("Elf32GetSymbol: Undefined", *ret, (Size?*Size:0), section);
+ TRACE("Elf32GetSymbol: Undefined %p", *ret, (Size?*Size:0), section);
return 0;
}
+ if( binding == STB_WEAK ) {
+ TRACE("Elf32GetSymbol: Weak, return %p+0x%x,section=%i", *ret, (Size?*Size:0), section);
+ return 2;
+ }
TRACE("Elf32GetSymbol: Found %p+0x%x,section=%i", *ret, (Size?*Size:0), section);
return 1;
}