loader/elf.c

   1 /*
   2  *      UNIX dynamic loader
   3  *
   4  * Currently only supports stuff using the dl* API.
   5  *
   6  * Copyright 1998 Marcus Meissner
   7  *
   8  * FIXME:       Small reentrancy problem.
   9  * IDEA(s):     could be used to split up shell32,comctl32...
  10  */
  11
  12 #include "config.h"
  13
  14 #include <assert.h>
  15 #include <stdio.h>
  16 #include <string.h>
  17 #include <sys/types.h>
  18
  19 #include "windows.h"
  20 #include "snoop.h"
  21 #include "process.h"
  22 #include "peexe.h"
  23 #include "heap.h"
  24 #include "pe_image.h"
  25 #include "module.h"
  26 #include "debug.h"
  27
  28 WINE_MODREF *
  29 ELF_CreateDummyModule( LPCSTR libname, LPCSTR modname, PDB32 *process )
  30 {
  31         PIMAGE_DOS_HEADER       dh;
  32         PIMAGE_NT_HEADERS       nth;
  33         PIMAGE_SECTION_HEADER   sh;
  34         WINE_MODREF *wm;
  35         HMODULE32 hmod;
  36
  37         wm=(WINE_MODREF*)HeapAlloc(process->heap,HEAP_ZERO_MEMORY,sizeof(*wm));
  38         wm->type = MODULE32_ELF;
  39
  40         /* FIXME: hmm, order? */
  41         wm->next = process->modref_list;
  42         process->modref_list = wm;
  43
  44         wm->modname = HEAP_strdupA(process->heap,0,modname);
  45         wm->longname = HEAP_strdupA(process->heap,0,libname);
  46
  47         hmod = (HMODULE32)HeapAlloc(process->heap,HEAP_ZERO_MEMORY,sizeof(IMAGE_DOS_HEADER)+sizeof(IMAGE_NT_HEADERS)+sizeof(IMAGE_SECTION_HEADER)+100);
  48         dh = (PIMAGE_DOS_HEADER)hmod;
  49         dh->e_magic = IMAGE_DOS_SIGNATURE;
  50         dh->e_lfanew = sizeof(IMAGE_DOS_HEADER);
  51         nth = PE_HEADER(hmod);
  52         nth->Signature = IMAGE_NT_SIGNATURE;
  53         nth->FileHeader.Machine = IMAGE_FILE_MACHINE_I386;
  54         nth->FileHeader.NumberOfSections = 1;
  55         nth->FileHeader.SizeOfOptionalHeader = sizeof(IMAGE_OPTIONAL_HEADER);
  56         nth->FileHeader.Characteristics =
  57                 IMAGE_FILE_RELOCS_STRIPPED|IMAGE_FILE_LINE_NUMS_STRIPPED|
  58                 IMAGE_FILE_LOCAL_SYMS_STRIPPED|IMAGE_FILE_32BIT_MACHINE|
  59                 IMAGE_FILE_DLL|IMAGE_FILE_DEBUG_STRIPPED;
  60         nth->OptionalHeader.Magic = IMAGE_NT_OPTIONAL_HDR_MAGIC;
  61         nth->OptionalHeader.SizeOfCode = 0;
  62         nth->OptionalHeader.SizeOfInitializedData = 0;
  63         nth->OptionalHeader.SizeOfUninitializedData = 0;
  64         nth->OptionalHeader.AddressOfEntryPoint = 0;
  65         nth->OptionalHeader.BaseOfCode          = 0;
  66         nth->OptionalHeader.MajorOperatingSystemVersion = 4;
  67         nth->OptionalHeader.MajorImageVersion   = 4;
  68         nth->OptionalHeader.SizeOfImage         = 0;
  69         nth->OptionalHeader.SizeOfHeaders       = 0;
  70         nth->OptionalHeader.Subsystem           = IMAGE_SUBSYSTEM_NATIVE;
  71         nth->OptionalHeader.DllCharacteristics  = 0;
  72         nth->OptionalHeader.NumberOfRvaAndSizes = 0;
  73
  74         /* allocate one code section that crosses the whole process range
  75          * (we could find out from internal tables ... hmm )
  76          */
  77         sh=(PIMAGE_SECTION_HEADER)(nth+1);
  78         strcpy(sh->Name,".text");
  79         sh->Misc.VirtualSize    = 0x7fffffff;
  80         sh->VirtualAddress      = 0x42; /* so snoop can use it ... */
  81         sh->SizeOfRawData       = 0x7fffffff;
  82         sh->PointerToRawData    = 0;
  83         sh->Characteristics     = IMAGE_SCN_CNT_CODE|IMAGE_SCN_CNT_INITIALIZED_DATA|IMAGE_SCN_MEM_EXECUTE|IMAGE_SCN_MEM_READ;
  84         wm->module = hmod;
  85         return wm;
  86 }
  87
  88
  89 #if defined(HAVE_LIBDL) && defined(HAVE_DLFCN_H)
  90
  91 #define UNIX_DLL_ENDING         "so"
  92
  93 #define STUBSIZE                4095
  94
  95 #include <dlfcn.h>
  96
  97 HMODULE32
  98 ELF_LoadLibraryEx32A(LPCSTR libname,PDB32 *process,HANDLE32 hf,DWORD flags) {
  99         WINE_MODREF     *wm;
 100         char            *modname,*s,*t,*x;
 101         LPVOID          *dlhandle;
 102
 103         t = HeapAlloc(process->heap,HEAP_ZERO_MEMORY,strlen(libname)+strlen("lib.so")+1);
 104         *t = '\0';
 105         /* copy path to tempvar ... */
 106         s=strrchr(libname,'/');
 107         if (!s)
 108                 s=strrchr(libname,'\\');
 109         if (s) {
 110                 strncpy(t,libname,s-libname+1);
 111                 t[s-libname+1]= '\0';
 112         } else
 113                 s = (LPSTR)libname;
 114         modname = s;
 115         /* append "lib" foo ".so" */
 116         strcat(t,"lib");
 117         x = t+strlen(t);
 118         strcat(t,s);
 119         s = strchr(x,'.');
 120         while (s) {
 121                 if (!strcasecmp(s,".dll")) {
 122                         strcpy(s+1,UNIX_DLL_ENDING);
 123                         break;
 124                 }
 125                 s=strchr(s+1,'.');
 126         }
 127
 128         /* FIXME: make UNIX filename from DOS fn? */
 129
 130         /* ... and open it */
 131         dlhandle = dlopen(t,RTLD_NOW);
 132         if (!dlhandle) {
 133                 HeapFree(process->heap,0,t);
 134                 return 0;
 135         }
 136
 137         wm = ELF_CreateDummyModule( t, modname, process );
 138         wm->binfmt.elf.dlhandle = dlhandle;
 139
 140         SNOOP_RegisterDLL(wm->module,libname,STUBSIZE/sizeof(ELF_STDCALL_STUB));
 141         return wm->module;
 142 }
 143
 144 FARPROC32
 145 ELF_FindExportedFunction( PDB32 *process,WINE_MODREF *wm, LPCSTR funcName) {
 146         LPVOID                  fun;
 147         int                     i,nrofargs = 0;
 148         ELF_STDCALL_STUB        *stub;
 149
 150         assert(wm->type == MODULE32_ELF);
 151         if (!HIWORD(funcName)) {
 152                 ERR(win32,"Can't import from UNIX dynamic libs by ordinal, sorry.\n");
 153                 return (FARPROC32)0;
 154         }
 155         fun = dlsym(wm->binfmt.elf.dlhandle,funcName);
 156         /* we sometimes have an excess '_' at the beginning of the name */
 157         if (!fun && (funcName[0]=='_')) {
 158                 funcName++ ;
 159                 fun = dlsym(wm->binfmt.elf.dlhandle,funcName);
 160         }
 161         if (!fun) {
 162                 /* Function@nrofargs usually marks a stdcall function
 163                  * with nrofargs bytes that are popped at the end
 164                  */
 165                 if (strchr(funcName,'@')) {
 166                         LPSTR   t,fn = HEAP_strdupA(process->heap,0,funcName);
 167
 168                         t = strchr(fn,'@');
 169                         *t = '\0';
 170                         nrofargs = 0;
 171                         sscanf(t+1,"%d",&nrofargs);
 172                         fun = dlsym(wm->binfmt.elf.dlhandle,fn);
 173                         HeapFree(process->heap,0,fn);
 174                 }
 175         }
 176         /* We sometimes have Win32 dlls implemented using stdcall but UNIX
 177          * dlls using cdecl. If we find out the number of args the function
 178          * uses, we remove them from the stack using two small stubs.
 179          */
 180         if (!wm->binfmt.elf.stubs) {
 181                 /* one page should suffice */
 182                 wm->binfmt.elf.stubs = VirtualAlloc(NULL,STUBSIZE,MEM_COMMIT|MEM_RESERVE,PAGE_EXECUTE_READWRITE);
 183                 memset(wm->binfmt.elf.stubs,0,STUBSIZE);
 184         }
 185         stub = wm->binfmt.elf.stubs;
 186         for (i=0;i<STUBSIZE/sizeof(ELF_STDCALL_STUB);i++) {
 187                 if (!stub->origfun)
 188                         break;
 189                 if (stub->origfun == (DWORD)fun)
 190                         break;
 191                 stub++;
 192         }
 193         if (i==STUBSIZE/sizeof(ELF_STDCALL_STUB)) {
 194                 ERR(win32,"please report, that there are not enough slots for stdcall stubs in the ELF loader.\n");
 195                 assert(i<STUBSIZE/sizeof(ELF_STDCALL_STUB));
 196         }
 197         if (!stub->origfun)
 198                 stub->origfun=(DWORD)fun; /* just a marker */
 199
 200         if (fun && nrofargs) { /* we don't need it for 0 args */
 201                 /* Selfmodifying entry/return stub for stdcall -> cdecl
 202                  * conversion.
 203                  *  - Pop returnaddress directly into our return code
 204                  *              popl <into code below>
 205                  *  - Replace it by pointer to start of our returncode
 206                  *              push $newret
 207                  *  - And call the original function
 208                  *              jmp $orgfun
 209                  *  - Remove the arguments no longer needed
 210                  * newret:      add esp, <nrofargs>
 211                  *  - Push the original returnvalue on the stack
 212                  *              pushl <poppedvalue>
 213                  *  - And return to it.
 214                  *              ret
 215                  */
 216
 217                 /* FIXME: The function stub is not reentrant. */
 218
 219                 ((LPBYTE)&(stub->popl))[0]        = 0x8f;
 220                 ((LPBYTE)&(stub->popl))[1]        = 0x05;
 221                 stub->addr_popped = (DWORD)&(stub->oldret);
 222                 stub->pushl1      = 0x68;
 223                 stub->newret      = (DWORD)&(stub->addesp);
 224                 stub->pushl2      = 0x68;
 225                 stub->origfun     = (DWORD)fun;
 226                 stub->ret1        = 0xc3;
 227                 ((LPBYTE)&(stub->addesp))[0]=0x83;
 228                 ((LPBYTE)&(stub->addesp))[1]=0xc4;
 229                 stub->nrofargs    = nrofargs;
 230                 stub->pushl3      = 0x68;
 231                         /* filled out by entrycode */
 232                 stub->oldret      = 0xdeadbeef;
 233                 stub->ret2        = 0xc3;
 234                 fun=(FARPROC32)stub;
 235         }
 236         if (!fun) {
 237                 FIXME(win32,"function %s not found: %s\n",funcName,dlerror());
 238                 return fun;
 239         }
 240         fun = SNOOP_GetProcAddress32(wm->module,funcName,stub-wm->binfmt.elf.stubs,fun);
 241         return (FARPROC32)fun;
 242 }
 243 #else
 244
 245 HMODULE32
 246 ELF_LoadLibraryEx32A(LPCSTR libname,PDB32 *process,HANDLE32 hf,DWORD flags) {
 247         return 0;
 248 }
 249 FARPROC32
 250 ELF_FindExportedFunction( PDB32 *process,WINE_MODREF *wm, LPCSTR funcName) {
 251         return (FARPROC32)0;
 252 }
 253
 254 #endif