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