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 "snoop.h"
  20 #include "process.h"
  21 #include "neexe.h"
  22 #include "heap.h"
  23 #include "module.h"
  24 #include "pe_image.h"
  25 #include "debugtools.h"
  26 #include "winerror.h"
  27 #include "elfdll.h"
  28
  29 DEFAULT_DEBUG_CHANNEL(win32)
  30
  31 #if defined(HAVE_DL_API)
  32
  33 #define UNIX_DLL_ENDING         "so"
  34
  35 #define STUBSIZE                4095
  36
  37 #include <dlfcn.h>
  38
  39
  40 static WINE_MODREF *ELF_CreateDummyModule( LPCSTR libname, LPCSTR modname )
  41 {
  42         PIMAGE_DOS_HEADER       dh;
  43         PIMAGE_NT_HEADERS       nth;
  44         PIMAGE_SECTION_HEADER   sh;
  45         WINE_MODREF *wm;
  46         HMODULE hmod;
  47
  48         wm=(WINE_MODREF*)HeapAlloc( GetProcessHeap(), HEAP_ZERO_MEMORY, sizeof(*wm) );
  49         wm->type = MODULE32_ELF;
  50
  51         /* FIXME: hmm, order? */
  52         wm->next = PROCESS_Current()->modref_list;
  53         PROCESS_Current()->modref_list = wm;
  54
  55         wm->modname = HEAP_strdupA( GetProcessHeap(), 0, modname );
  56         wm->filename = HEAP_strdupA( GetProcessHeap(), 0, libname );
  57         wm->short_modname = wm->modname;
  58         wm->short_filename = wm->filename;
  59
  60         hmod = (HMODULE)HeapAlloc( GetProcessHeap(), HEAP_ZERO_MEMORY,
  61                                      sizeof(IMAGE_DOS_HEADER) +
  62                                      sizeof(IMAGE_NT_HEADERS) +
  63                                      sizeof(IMAGE_SECTION_HEADER) + 100 );
  64         dh = (PIMAGE_DOS_HEADER)hmod;
  65         dh->e_magic = IMAGE_DOS_SIGNATURE;
  66         dh->e_lfanew = sizeof(IMAGE_DOS_HEADER);
  67         nth = PE_HEADER(hmod);
  68         nth->Signature = IMAGE_NT_SIGNATURE;
  69         nth->FileHeader.Machine = IMAGE_FILE_MACHINE_I386;
  70         nth->FileHeader.NumberOfSections = 1;
  71         nth->FileHeader.SizeOfOptionalHeader = sizeof(IMAGE_OPTIONAL_HEADER);
  72         nth->FileHeader.Characteristics =
  73                 IMAGE_FILE_RELOCS_STRIPPED|IMAGE_FILE_LINE_NUMS_STRIPPED|
  74                 IMAGE_FILE_LOCAL_SYMS_STRIPPED|IMAGE_FILE_32BIT_MACHINE|
  75                 IMAGE_FILE_DLL|IMAGE_FILE_DEBUG_STRIPPED;
  76         nth->OptionalHeader.Magic = IMAGE_NT_OPTIONAL_HDR_MAGIC;
  77         nth->OptionalHeader.SizeOfCode = 0;
  78         nth->OptionalHeader.SizeOfInitializedData = 0;
  79         nth->OptionalHeader.SizeOfUninitializedData = 0;
  80         nth->OptionalHeader.AddressOfEntryPoint = 0;
  81         nth->OptionalHeader.BaseOfCode          = 0;
  82         nth->OptionalHeader.MajorOperatingSystemVersion = 4;
  83         nth->OptionalHeader.MajorImageVersion   = 4;
  84         nth->OptionalHeader.SizeOfImage         = 0;
  85         nth->OptionalHeader.SizeOfHeaders       = 0;
  86         nth->OptionalHeader.Subsystem           = IMAGE_SUBSYSTEM_NATIVE;
  87         nth->OptionalHeader.DllCharacteristics  = 0;
  88         nth->OptionalHeader.NumberOfRvaAndSizes = 0;
  89
  90         /* allocate one code section that crosses the whole process range
  91          * (we could find out from internal tables ... hmm )
  92          */
  93         sh=(PIMAGE_SECTION_HEADER)(nth+1);
  94         strcpy(sh->Name,".text");
  95         sh->Misc.VirtualSize    = 0x7fffffff;
  96         sh->VirtualAddress      = 0x42; /* so snoop can use it ... */
  97         sh->SizeOfRawData       = 0x7fffffff;
  98         sh->PointerToRawData    = 0;
  99         sh->Characteristics     = IMAGE_SCN_CNT_CODE|IMAGE_SCN_CNT_INITIALIZED_DATA|IMAGE_SCN_MEM_EXECUTE|IMAGE_SCN_MEM_READ;
 100         wm->module = hmod;
 101         return wm;
 102 }
 103
 104 WINE_MODREF *ELF_LoadLibraryExA( LPCSTR libname, DWORD flags)
 105 {
 106         WINE_MODREF     *wm;
 107         char            *modname,*s,*t,*x;
 108         LPVOID          *dlhandle;
 109
 110         t = HeapAlloc( GetProcessHeap(), HEAP_ZERO_MEMORY,
 111                        strlen(libname) + strlen("lib.so") + 1 );
 112         *t = '\0';
 113         /* copy path to tempvar ... */
 114         s=strrchr(libname,'/');
 115         if (!s)
 116                 s=strrchr(libname,'\\');
 117         if (s) {
 118                 s++; /* skip / or \ */
 119                 /* copy everything up to s-1 */
 120                 memcpy(t,libname,s-libname);
 121                 t[s-libname]= '\0';
 122         } else
 123                 s = (LPSTR)libname;
 124         modname = s;
 125         /* append "lib" foo ".so" */
 126         strcat(t,"lib");
 127         x = t+strlen(t);
 128         strcat(t,s);
 129         s = strchr(x,'.');
 130         if (s) {
 131             while (s) {
 132                 if (!strcasecmp(s,".dll")) {
 133                     strcpy(s+1,UNIX_DLL_ENDING);
 134                     break;
 135                 }
 136                 s=strchr(s+1,'.');
 137             }
 138         } else {
 139                 strcat(x,"."UNIX_DLL_ENDING);
 140         }
 141
 142         /* FIXME: make UNIX filename from DOS fn? */
 143
 144         /* ... and open it */
 145         dlhandle = ELFDLL_dlopen(t,RTLD_NOW);
 146         if (!dlhandle) {
 147                 HeapFree( GetProcessHeap(), 0, t );
 148                 SetLastError( ERROR_FILE_NOT_FOUND );
 149                 return NULL;
 150         }
 151
 152         wm = ELF_CreateDummyModule( t, modname );
 153         wm->binfmt.elf.dlhandle = dlhandle;
 154
 155         SNOOP_RegisterDLL(wm->module,libname,STUBSIZE/sizeof(ELF_STDCALL_STUB));
 156         return wm;
 157 }
 158
 159 FARPROC ELF_FindExportedFunction( WINE_MODREF *wm, LPCSTR funcName)
 160 {
 161         LPVOID                  fun;
 162         int                     i,nrofargs = 0;
 163         ELF_STDCALL_STUB        *stub;
 164
 165         assert(wm->type == MODULE32_ELF);
 166         if (!HIWORD(funcName)) {
 167                 ERR("Can't import from UNIX dynamic libs by ordinal, sorry.\n");
 168                 return (FARPROC)0;
 169         }
 170         fun = dlsym(wm->binfmt.elf.dlhandle,funcName);
 171         /* we sometimes have an excess '_' at the beginning of the name */
 172         if (!fun && (funcName[0]=='_')) {
 173                 funcName++ ;
 174                 fun = dlsym(wm->binfmt.elf.dlhandle,funcName);
 175         }
 176         if (!fun) {
 177                 /* Function@nrofargs usually marks a stdcall function
 178                  * with nrofargs bytes that are popped at the end
 179                  */
 180                 if (strchr(funcName,'@')) {
 181                         LPSTR   t,fn = HEAP_strdupA( GetProcessHeap(), 0, funcName );
 182
 183                         t = strchr(fn,'@');
 184                         *t = '\0';
 185                         nrofargs = 0;
 186                         sscanf(t+1,"%d",&nrofargs);
 187                         fun = dlsym(wm->binfmt.elf.dlhandle,fn);
 188                         HeapFree( GetProcessHeap(), 0, fn );
 189                 }
 190         }
 191         /* We sometimes have Win32 dlls implemented using stdcall but UNIX
 192          * dlls using cdecl. If we find out the number of args the function
 193          * uses, we remove them from the stack using two small stubs.
 194          */
 195         if (!wm->binfmt.elf.stubs) {
 196                 /* one page should suffice */
 197                 wm->binfmt.elf.stubs = VirtualAlloc(NULL,STUBSIZE,MEM_COMMIT|MEM_RESERVE,PAGE_EXECUTE_READWRITE);
 198                 memset(wm->binfmt.elf.stubs,0,STUBSIZE);
 199         }
 200         stub = wm->binfmt.elf.stubs;
 201         for (i=0;i<STUBSIZE/sizeof(ELF_STDCALL_STUB);i++) {
 202                 if (!stub->origfun)
 203                         break;
 204                 if (stub->origfun == (DWORD)fun)
 205                         break;
 206                 stub++;
 207         }
 208         if (i==STUBSIZE/sizeof(ELF_STDCALL_STUB)) {
 209                 ERR("please report, that there are not enough slots for stdcall stubs in the ELF loader.\n");
 210                 assert(i<STUBSIZE/sizeof(ELF_STDCALL_STUB));
 211         }
 212         if (!stub->origfun)
 213                 stub->origfun=(DWORD)fun; /* just a marker */
 214
 215         if (fun && nrofargs) { /* we don't need it for 0 args */
 216                 /* Selfmodifying entry/return stub for stdcall -> cdecl
 217                  * conversion.
 218                  *  - Pop returnaddress directly into our return code
 219                  *              popl <into code below>
 220                  *  - Replace it by pointer to start of our returncode
 221                  *              push $newret
 222                  *  - And call the original function
 223                  *              jmp $orgfun
 224                  *  - Remove the arguments no longer needed
 225                  * newret:      add esp, <nrofargs>
 226                  *  - Push the original returnvalue on the stack
 227                  *              pushl <poppedvalue>
 228                  *  - And return to it.
 229                  *              ret
 230                  */
 231
 232                 /* FIXME: The function stub is not reentrant. */
 233
 234                 ((LPBYTE)&(stub->popl))[0]        = 0x8f;
 235                 ((LPBYTE)&(stub->popl))[1]        = 0x05;
 236                 stub->addr_popped = (DWORD)&(stub->oldret);
 237                 stub->pushl1      = 0x68;
 238                 stub->newret      = (DWORD)&(stub->addesp);
 239                 stub->pushl2      = 0x68;
 240                 stub->origfun     = (DWORD)fun;
 241                 stub->ret1        = 0xc3;
 242                 ((LPBYTE)&(stub->addesp))[0]=0x83;
 243                 ((LPBYTE)&(stub->addesp))[1]=0xc4;
 244                 stub->nrofargs    = nrofargs;
 245                 stub->pushl3      = 0x68;
 246                         /* filled out by entrycode */
 247                 stub->oldret      = 0xdeadbeef;
 248                 stub->ret2        = 0xc3;
 249                 fun=(FARPROC)stub;
 250         }
 251         if (!fun) {
 252                 FIXME("function %s not found: %s\n",funcName,dlerror());
 253                 return fun;
 254         }
 255         fun = SNOOP_GetProcAddress(wm->module,funcName,stub-wm->binfmt.elf.stubs,fun);
 256         return (FARPROC)fun;
 257 }
 258
 259
 260 /***************************************************************************
 261  *      ELF_UnloadLibrary
 262  *
 263  * Unload the elf library and free the modref
 264  */
 265 void ELF_UnloadLibrary(WINE_MODREF *wm)
 266 {
 267         /* FIXME: do something here */
 268 }
 269
 270 #else
 271
 272 WINE_MODREF *ELF_LoadLibraryExA( LPCSTR libname, DWORD flags)
 273 {
 274         return NULL;
 275 }
 276
 277 void ELF_UnloadLibrary(WINE_MODREF *wm)
 278 {
 279 }
 280
 281 FARPROC ELF_FindExportedFunction( WINE_MODREF *wm, LPCSTR funcName)
 282 {
 283         return (FARPROC)0;
 284 }
 285
 286 #endif