/** Perform relocations for am image.
* @param image Image to relocate.
* @return Status code describing result of the operation. */
status_t arch_rtld_image_relocate(rtld_image_t *image) {
elf_rela_t *relocs;
status_t ret;
/* First perform RELA relocations. */
relocs = (elf_rela_t *)image->dynamic[ELF_DT_REL_TYPE];
ret = do_relocations(image, relocs, image->dynamic[ELF_DT_RELSZ_TYPE]);
if(ret != STATUS_SUCCESS)
return ret;
/* Then PLT relocations. */
relocs = (elf_rela_t *)image->dynamic[ELF_DT_JMPREL];
return do_relocations(image, relocs, image->dynamic[ELF_DT_PLTRELSZ]);
}
int init_noinit_relro(int argc, char **argv, char **env)
{
relro_pre();
do_relocations();
relro_post();
return 0;
}
__attribute__((section(".text._init"))) int init(int argc, char** argv,
char** env) {
do_relocations();
original_init(argc, argv, env);
// Ensure there is no tail-call optimization, avoiding the use of the
// B.W instruction in Thumb for the call above.
return 0;
}
int init_relro(int argc, char **argv, char **env)
{
relro_pre();
do_relocations();
relro_post();
original_init(argc, argv, env);
return 0;
}
static inline __attribute__((always_inline)) void do_relocations_with_relro(
void) {
long page_size = sysconf_cb(_SC_PAGESIZE);
uintptr_t aligned_relro_start = ((uintptr_t)relro_start) & ~(page_size - 1);
// The relro segment may not end at a page boundary. If that's the case, the
// remainder of the page needs to stay read-write, so the last page is never
// set read-only. Thus the aligned relro end is page-rounded down.
uintptr_t aligned_relro_end = ((uintptr_t)relro_end) & ~(page_size - 1);
// By the time the injected code runs, the relro segment is read-only. But
// we want to apply relocations in it, so we set it r/w first. We'll restore
// it to read-only in relro_post.
mprotect_cb((void*)aligned_relro_start,
aligned_relro_end - aligned_relro_start, PROT_READ | PROT_WRITE);
do_relocations();
mprotect_cb((void*)aligned_relro_start,
aligned_relro_end - aligned_relro_start, PROT_READ);
// mprotect_cb and sysconf_cb are allocated in .bss, so we need to restore
// them to a NULL value.
mprotect_cb = NULL;
sysconf_cb = NULL;
}
/**********************************************************************
* PE_LoadImage
* Load one PE format DLL/EXE into memory
*
* Unluckily we can't just mmap the sections where we want them, for
* (at least) Linux does only support offsets which are page-aligned.
*
* BUT we have to map the whole image anyway, for Win32 programs sometimes
* want to access them. (HMODULE32 point to the start of it)
*/
HMODULE PE_LoadImage( int handle, LPCSTR filename, WORD *version )
{
HMODULE hModule;
HANDLE mapping;
IMAGE_NT_HEADERS *nt;
IMAGE_SECTION_HEADER *pe_sec;
IMAGE_DATA_DIRECTORY *dir;
// BY_HANDLE_FILE_INFORMATION bhfi;
int i, rawsize, lowest_va, vma_size, file_size = 0;
DWORD load_addr = 0, aoep, reloc = 0;
// struct get_read_fd_request *req = get_req_buffer();
int unix_handle = handle;
int page_size = getpagesize();
// if ( GetFileInformationByHandle( hFile, &bhfi ) )
// file_size = bhfi.nFileSizeLow;
file_size=lseek(handle, 0, SEEK_END);
lseek(handle, 0, SEEK_SET);
// fix CreateFileMappingA
mapping = CreateFileMappingA( handle, NULL, PAGE_READONLY | SEC_COMMIT,
0, 0, NULL );
if (!mapping)
{
WARN("CreateFileMapping error %ld\n", GetLastError() );
return 0;
}
// hModule = (HMODULE)MapViewOfFile( mapping, FILE_MAP_READ, 0, 0, 0 );
hModule=(HMODULE)mapping;
// CloseHandle( mapping );
if (!hModule)
{
WARN("MapViewOfFile error %ld\n", GetLastError() );
return 0;
}
if ( *(WORD*)hModule !=IMAGE_DOS_SIGNATURE)
{
WARN("%s image doesn't have DOS signature, but 0x%04x\n", filename,*(WORD*)hModule);
goto error;
}
nt = PE_HEADER( hModule );
if ( nt->Signature != IMAGE_NT_SIGNATURE )
{
WARN("%s image doesn't have PE signature, but 0x%08lx\n", filename, nt->Signature );
goto error;
}
if ( nt->FileHeader.Machine != IMAGE_FILE_MACHINE_I386 )
{
dbg_printf("Trying to load PE image for unsupported architecture (");
switch (nt->FileHeader.Machine)
{
case IMAGE_FILE_MACHINE_UNKNOWN: dbg_printf("Unknown"); break;
case IMAGE_FILE_MACHINE_I860: dbg_printf("I860"); break;
case IMAGE_FILE_MACHINE_R3000: dbg_printf("R3000"); break;
case IMAGE_FILE_MACHINE_R4000: dbg_printf("R4000"); break;
case IMAGE_FILE_MACHINE_R10000: dbg_printf("R10000"); break;
case IMAGE_FILE_MACHINE_ALPHA: dbg_printf("Alpha"); break;
case IMAGE_FILE_MACHINE_POWERPC: dbg_printf("PowerPC"); break;
default: dbg_printf("Unknown-%04x", nt->FileHeader.Machine); break;
}
dbg_printf(")\n");
goto error;
}
pe_sec = PE_SECTIONS( hModule );
rawsize = 0; lowest_va = 0x10000;
for (i = 0; i < nt->FileHeader.NumberOfSections; i++)
{
if (lowest_va > pe_sec[i].VirtualAddress)
lowest_va = pe_sec[i].VirtualAddress;
if (pe_sec[i].Characteristics & IMAGE_SCN_CNT_UNINITIALIZED_DATA)
continue;
if (pe_sec[i].PointerToRawData+pe_sec[i].SizeOfRawData > rawsize)
rawsize = pe_sec[i].PointerToRawData+pe_sec[i].SizeOfRawData;
}
if ( file_size && file_size < rawsize )
{
ERR("PE module is too small (header: %d, filesize: %d), "
"probably truncated download?\n",
rawsize, file_size );
goto error;
}
aoep = nt->OptionalHeader.AddressOfEntryPoint;
if (aoep && (aoep < lowest_va))
FIXME("VIRUS WARNING: '%s' has an invalid entrypoint (0x%08lx) "
"below the first virtual address (0x%08x) "
"(possibly infected by Tchernobyl/SpaceFiller virus)!\n",
filename, aoep, lowest_va );
/* FIXME: Hack! While we don't really support shared sections yet,
* this checks for those special cases where the whole DLL
* consists only of shared sections and is mapped into the
* shared address space > 2GB. In this case, we assume that
* the module got mapped at its base address. Thus we simply
* check whether the module has actually been mapped there
* and use it, if so. This is needed to get Win95 USER32.DLL
* to work (until we support shared sections properly).
*/
if ( nt->OptionalHeader.ImageBase & 0x80000000 &&
!strstr(filename, "xanlib.dll"))
{
HMODULE sharedMod = (HMODULE)nt->OptionalHeader.ImageBase;
IMAGE_NT_HEADERS *sharedNt = (PIMAGE_NT_HEADERS)
( (LPBYTE)sharedMod + ((LPBYTE)nt - (LPBYTE)hModule) );
/* Well, this check is not really comprehensive,
but should be good enough for now ... */
if ( !IsBadReadPtr( (LPBYTE)sharedMod, sizeof(IMAGE_DOS_HEADER) )
&& memcmp( (LPBYTE)sharedMod, (LPBYTE)hModule, sizeof(IMAGE_DOS_HEADER) ) == 0
&& !IsBadReadPtr( sharedNt, sizeof(IMAGE_NT_HEADERS) )
&& memcmp( sharedNt, nt, sizeof(IMAGE_NT_HEADERS) ) == 0 )
{
UnmapViewOfFile( (LPVOID)hModule );
return sharedMod;
}
}
load_addr = nt->OptionalHeader.ImageBase;
vma_size = calc_vma_size( hModule );
load_addr = (DWORD)VirtualAlloc( (void*)load_addr, vma_size,
MEM_RESERVE | MEM_COMMIT,
PAGE_EXECUTE_READWRITE );
if (load_addr == 0)
{
FIXME("We need to perform base relocations for %s\n", filename);
dir = nt->OptionalHeader.DataDirectory+IMAGE_DIRECTORY_ENTRY_BASERELOC;
if (dir->Size)
reloc = dir->VirtualAddress;
else
{
FIXME( "FATAL: Need to relocate %s, but no relocation records present (%s). Try to run that file directly !\n",
filename,
(nt->FileHeader.Characteristics&IMAGE_FILE_RELOCS_STRIPPED)?
"stripped during link" : "unknown reason" );
goto error;
}
/* FIXME: If we need to relocate a system DLL (base > 2GB) we should
* really make sure that the *new* base address is also > 2GB.
* Some DLLs really check the MSB of the module handle :-/
*/
if ( nt->OptionalHeader.ImageBase & 0x80000000 )
ERR( "Forced to relocate system DLL (base > 2GB). This is not good.\n" );
load_addr = (DWORD)VirtualAlloc( NULL, vma_size,
MEM_RESERVE | MEM_COMMIT,
PAGE_EXECUTE_READWRITE );
if (!load_addr) {
FIXME_(win32)(
"FATAL: Couldn't load module %s (out of memory, %d needed)!\n", filename, vma_size);
goto error;
}
}
TRACE("Load addr is %lx (base %lx), range %x\n",
load_addr, nt->OptionalHeader.ImageBase, vma_size );
TRACE_(segment)("Loading %s at %lx, range %x\n",
filename, load_addr, vma_size );
#if 0
*(PIMAGE_DOS_HEADER)load_addr = *(PIMAGE_DOS_HEADER)hModule;
*PE_HEADER( load_addr ) = *nt;
memcpy( PE_SECTIONS(load_addr), PE_SECTIONS(hModule),
sizeof(IMAGE_SECTION_HEADER) * nt->FileHeader.NumberOfSections );
memcpy( load_addr, hModule, lowest_fa );
#endif
if ((void*)FILE_dommap( handle, (void *)load_addr, 0, nt->OptionalHeader.SizeOfHeaders,
0, 0, PROT_EXEC | PROT_WRITE | PROT_READ,
MAP_PRIVATE | MAP_FIXED ) != (void*)load_addr)
{
ERR_(win32)( "Critical Error: failed to map PE header to necessary address.\n");
goto error;
}
pe_sec = PE_SECTIONS( hModule );
for (i = 0; i < nt->FileHeader.NumberOfSections; i++, pe_sec++)
{
if (!pe_sec->SizeOfRawData || !pe_sec->PointerToRawData) continue;
TRACE("%s: mmaping section %s at %p off %lx size %lx/%lx\n",
filename, pe_sec->Name, (void*)RVA(pe_sec->VirtualAddress),
pe_sec->PointerToRawData, pe_sec->SizeOfRawData, pe_sec->Misc.VirtualSize );
if ((void*)FILE_dommap( unix_handle, (void*)RVA(pe_sec->VirtualAddress),
0, pe_sec->SizeOfRawData, 0, pe_sec->PointerToRawData,
PROT_EXEC | PROT_WRITE | PROT_READ,
MAP_PRIVATE | MAP_FIXED ) != (void*)RVA(pe_sec->VirtualAddress))
{
ERR_(win32)( "Critical Error: failed to map PE section to necessary address.\n");
goto error;
}
if ((pe_sec->SizeOfRawData < pe_sec->Misc.VirtualSize) &&
(pe_sec->SizeOfRawData & (page_size-1)))
{
DWORD end = (pe_sec->SizeOfRawData & ~(page_size-1)) + page_size;
if (end > pe_sec->Misc.VirtualSize) end = pe_sec->Misc.VirtualSize;
TRACE("clearing %p - %p\n",
RVA(pe_sec->VirtualAddress) + pe_sec->SizeOfRawData,
RVA(pe_sec->VirtualAddress) + end );
memset( (char*)RVA(pe_sec->VirtualAddress) + pe_sec->SizeOfRawData, 0,
end - pe_sec->SizeOfRawData );
}
}
if ( reloc )
do_relocations( load_addr, (IMAGE_BASE_RELOCATION *)RVA(reloc) );
*version = ( (nt->OptionalHeader.MajorSubsystemVersion & 0xff) << 8 )
| (nt->OptionalHeader.MinorSubsystemVersion & 0xff);
UnmapViewOfFile( (LPVOID)hModule );
return (HMODULE)load_addr;
error:
if (unix_handle != -1) close( unix_handle );
if (load_addr)
VirtualFree( (LPVOID)load_addr, 0, MEM_RELEASE );
UnmapViewOfFile( (LPVOID)hModule );
return 0;
}
__attribute__((section(".text._init_noinit"))) int init_noinit(int argc,
char** argv,
char** env) {
do_relocations();
return 0;
}
int init_noinit(int argc, char **argv, char **env)
{
do_relocations();
return 0;
}