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