2 files changed, 140 insertions, 54 deletions

diff --git a/src/dlfcn.c b/src/dlfcn.c
index abbd58d..86f24df 100644
--- a/src/dlfcn.c
+++ b/src/dlfcn.c
@@ -24,9 +24,6 @@
  * THE SOFTWARE.

  */

 

-#ifndef _WIN32_WINNT

-#define _WIN32_WINNT 0x0501

-#endif

 #ifdef _DEBUG

 #define _CRTDBG_MAP_ALLOC

 #include <stdlib.h>

@@ -36,13 +33,26 @@
 #include <stdio.h>

 #include <stdlib.h>

 

+/* Older versions do not have this type */

+#if _WIN32_WINNT < 0x0500

+typedef ULONG ULONG_PTR;

+#endif

+

+/* Older SDK versions do not have these macros */

+#ifndef GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS

+#define GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS 0x4

+#endif

+#ifndef GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT

+#define GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT 0x2

+#endif

+

 #ifdef _MSC_VER

 /* https://docs.microsoft.com/en-us/cpp/intrinsics/returnaddress */

-#pragma intrinsic(_ReturnAddress)

+#pragma intrinsic( _ReturnAddress )

 #else

 /* https://gcc.gnu.org/onlinedocs/gcc/Return-Address.html */

 #ifndef _ReturnAddress

-#define _ReturnAddress() (__builtin_extract_return_addr(__builtin_return_address(0)))

+#define _ReturnAddress( ) ( __builtin_extract_return_addr( __builtin_return_address( 0 ) ) )

 #endif

 #endif

 

@@ -51,6 +61,16 @@
 #endif

 #include "dlfcn.h"

 

+#if defined( _MSC_VER ) && _MSC_VER >= 1300

+/* https://docs.microsoft.com/en-us/cpp/cpp/noinline */

+#define DLFCN_NOINLINE __declspec( noinline )

+#elif defined( __GNUC__ ) && ( ( __GNUC__ > 3 ) || ( __GNUC__ == 3 && __GNUC_MINOR__ >= 1 ) )

+/* https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html */

+#define DLFCN_NOINLINE __attribute__(( noinline ))

+#else

+#define DLFCN_NOINLINE

+#endif

+

 /* Note:

  * MSDN says these functions are not thread-safe. We make no efforts to have

  * any kind of thread safety.

@@ -90,18 +110,15 @@ static BOOL local_add( HMODULE hModule )
     pobject = local_search( hModule );

 

     /* Do not add object again if it's already on the list */

-    if( pobject )

+    if( pobject != NULL )

         return TRUE;

 

     for( pobject = &first_object; pobject->next; pobject = pobject->next );

 

-    nobject = (local_object*) malloc( sizeof( local_object ) );

+    nobject = (local_object *) malloc( sizeof( local_object ) );

 

     if( !nobject )

-    {

-        SetLastError( ERROR_NOT_ENOUGH_MEMORY );

         return FALSE;

-    }

 

     pobject->next = nobject;

     nobject->next = NULL;

@@ -120,7 +137,7 @@ static void local_rem( HMODULE hModule )
 

     pobject = local_search( hModule );

 

-    if( !pobject )

+    if( pobject == NULL )

         return;

 

     if( pobject->next )

@@ -139,17 +156,11 @@ static void local_rem( HMODULE hModule )
 static char error_buffer[65535];

 static BOOL error_occurred;

 

-static void save_err_str( const char *str )

+static void save_err_str( const char *str, DWORD dwMessageId )

 {

-    DWORD dwMessageId;

     DWORD ret;

     size_t pos, len;

 

-    dwMessageId = GetLastError( );

-

-    if( dwMessageId == 0 )

-        return;

-

     len = strlen( str );

     if( len > sizeof( error_buffer ) - 5 )

         len = sizeof( error_buffer ) - 5;

@@ -159,7 +170,7 @@ static void save_err_str( const char *str )
       */

     pos = 0;

     error_buffer[pos++] = '"';

-    memcpy( error_buffer+pos, str, len );

+    memcpy( error_buffer + pos, str, len );

     pos += len;

     error_buffer[pos++] = '"';

     error_buffer[pos++] = ':';

@@ -167,7 +178,7 @@ static void save_err_str( const char *str )
 

     ret = FormatMessageA( FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, NULL, dwMessageId,

         MAKELANGID( LANG_NEUTRAL, SUBLANG_DEFAULT ),

-        error_buffer+pos, (DWORD) (sizeof(error_buffer)-pos), NULL );

+        error_buffer + pos, (DWORD) ( sizeof( error_buffer ) - pos ), NULL );

     pos += ret;

 

     /* When FormatMessageA() fails it returns zero and does not touch buffer

@@ -185,7 +196,7 @@ static void save_err_str( const char *str )
     error_occurred = TRUE;

 }

 

-static void save_err_ptr_str( const void *ptr )

+static void save_err_ptr_str( const void *ptr, DWORD dwMessageId )

 {

     char ptr_buf[2 + 2 * sizeof( ptr ) + 1];

     char num;

@@ -196,28 +207,91 @@ static void save_err_ptr_str( const void *ptr )
 

     for( i = 0; i < 2 * sizeof( ptr ); i++ )

     {

-        num = ( ( (ULONG_PTR) ptr ) >> ( 8 * sizeof( ptr ) - 4 * ( i + 1 ) ) ) & 0xF;

-        ptr_buf[2+i] = num + ( ( num < 0xA ) ? '0' : ( 'A' - 0xA ) );

+        num = (char) ( ( ( (ULONG_PTR) ptr ) >> ( 8 * sizeof( ptr ) - 4 * ( i + 1 ) ) ) & 0xF );

+        ptr_buf[2 + i] = num + ( ( num < 0xA ) ? '0' : ( 'A' - 0xA ) );

     }

 

     ptr_buf[2 + 2 * sizeof( ptr )] = 0;

 

-    save_err_str( ptr_buf );

+    save_err_str( ptr_buf, dwMessageId );

+}

+

+static HMODULE MyGetModuleHandleFromAddress( void *addr )

+{

+    static BOOL (WINAPI *GetModuleHandleExAPtr)(DWORD, LPCSTR, HMODULE *) = NULL;

+    static BOOL failed = FALSE;

+    HMODULE kernel32;

+    HMODULE hModule;

+    MEMORY_BASIC_INFORMATION info;

+    SIZE_T sLen;

+

+    if( !failed && GetModuleHandleExAPtr == NULL )

+    {

+        kernel32 = GetModuleHandleA( "Kernel32.dll" );

+        if( kernel32 != NULL )

+            GetModuleHandleExAPtr = (BOOL (WINAPI *)(DWORD, LPCSTR, HMODULE *)) GetProcAddress( kernel32, "GetModuleHandleExA" );

+        if( GetModuleHandleExAPtr == NULL )

+            failed = TRUE;

+    }

+

+    if( !failed )

+    {

+        /* If GetModuleHandleExA is available use it with GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS */

+        if( !GetModuleHandleExAPtr( GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS | GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT, (LPCSTR) addr, &hModule ) )

+            return NULL;

+    }

+    else

+    {

+        /* To get HMODULE from address use undocumented hack from https://stackoverflow.com/a/2396380

+         * The HMODULE of a DLL is the same value as the module's base address.

+         */

+        sLen = VirtualQuery( addr, &info, sizeof( info ) );

+        if( sLen != sizeof( info ) )

+            return NULL;

+        hModule = (HMODULE) info.AllocationBase;

+    }

+

+    return hModule;

 }

 

 /* Load Psapi.dll at runtime, this avoids linking caveat */

 static BOOL MyEnumProcessModules( HANDLE hProcess, HMODULE *lphModule, DWORD cb, LPDWORD lpcbNeeded )

 {

-    static BOOL (WINAPI *EnumProcessModulesPtr)(HANDLE, HMODULE *, DWORD, LPDWORD);

+    static BOOL (WINAPI *EnumProcessModulesPtr)(HANDLE, HMODULE *, DWORD, LPDWORD) = NULL;

+    static BOOL failed = FALSE;

+    UINT uMode;

     HMODULE psapi;

 

-    if( !EnumProcessModulesPtr )

+    if( failed )

+        return FALSE;

+

+    if( EnumProcessModulesPtr == NULL )

     {

-        psapi = LoadLibraryA( "Psapi.dll" );

-        if( psapi )

-            EnumProcessModulesPtr = (BOOL (WINAPI *)(HANDLE, HMODULE *, DWORD, LPDWORD)) GetProcAddress( psapi, "EnumProcessModules" );

-        if( !EnumProcessModulesPtr )

-            return 0;

+        /* Windows 7 and newer versions have K32EnumProcessModules in Kernel32.dll which is always pre-loaded */

+        psapi = GetModuleHandleA( "Kernel32.dll" );

+        if( psapi != NULL )

+            EnumProcessModulesPtr = (BOOL (WINAPI *)(HANDLE, HMODULE *, DWORD, LPDWORD)) GetProcAddress( psapi, "K32EnumProcessModules" );

+

+        /* Windows Vista and older version have EnumProcessModules in Psapi.dll which needs to be loaded */

+        if( EnumProcessModulesPtr == NULL )

+        {

+            /* Do not let Windows display the critical-error-handler message box */

+            uMode = SetErrorMode( SEM_FAILCRITICALERRORS );

+            psapi = LoadLibraryA( "Psapi.dll" );

+            if( psapi != NULL )

+            {

+                EnumProcessModulesPtr = (BOOL (WINAPI *)(HANDLE, HMODULE *, DWORD, LPDWORD)) GetProcAddress( psapi, "EnumProcessModules" );

+                if( EnumProcessModulesPtr == NULL )

+                    FreeLibrary( psapi );

+            }

+            SetErrorMode( uMode );

+        }

+

+        if( EnumProcessModulesPtr == NULL )

+        {

+            failed = TRUE;

+            return FALSE;

+        }

     }

 

     return EnumProcessModulesPtr( hProcess, lphModule, cb, lpcbNeeded );

@@ -234,9 +308,9 @@ void *dlopen( const char *file, int mode )
     /* Do not let Windows display the critical-error-handler message box */

     uMode = SetErrorMode( SEM_FAILCRITICALERRORS );

 

-    if( file == 0 )

+    if( file == NULL )

     {

-        /* POSIX says that if the value of file is 0, a handle on a global

+        /* POSIX says that if the value of file is NULL, a handle on a global

          * symbol object must be provided. That object must be able to access

          * all symbols from the original program file, and any objects loaded

          * with the RTLD_GLOBAL flag.

@@ -249,7 +323,7 @@ void *dlopen( const char *file, int mode )
         hModule = GetModuleHandle( NULL );

 

         if( !hModule )

-            save_err_str( "(null)" );

+            save_err_str( "(null)", GetLastError( ) );

     }

     else

     {

@@ -262,8 +336,7 @@ void *dlopen( const char *file, int mode )
 

         if( len >= sizeof( lpFileName ) )

         {

-            SetLastError( ERROR_FILENAME_EXCED_RANGE );

-            save_err_str( file );

+            save_err_str( file, ERROR_FILENAME_EXCED_RANGE );

             hModule = NULL;

         }

         else

@@ -292,7 +365,7 @@ void *dlopen( const char *file, int mode )
 

             if( !hModule )

             {

-                save_err_str( lpFileName );

+                save_err_str( lpFileName, GetLastError( ) );

             }

             else

             {

@@ -312,7 +385,7 @@ void *dlopen( const char *file, int mode )
                 {

                     if( !local_add( hModule ) )

                     {

-                        save_err_str( lpFileName );

+                        save_err_str( lpFileName, ERROR_NOT_ENOUGH_MEMORY );

                         FreeLibrary( hModule );

                         hModule = NULL;

                     }

@@ -347,7 +420,7 @@ int dlclose( void *handle )
     if( ret )

         local_rem( hModule );

     else

-        save_err_ptr_str( handle );

+        save_err_ptr_str( handle, GetLastError( ) );

 

     /* dlclose's return value in inverted in relation to FreeLibrary's. */

     ret = !ret;

@@ -355,21 +428,21 @@ int dlclose( void *handle )
     return (int) ret;

 }

 

-__declspec(noinline) /* Needed for _ReturnAddress() */

+DLFCN_NOINLINE /* Needed for _ReturnAddress() */

 DLFCN_EXPORT

 void *dlsym( void *handle, const char *name )

 {

     FARPROC symbol;

     HMODULE hCaller;

     HMODULE hModule;

-    HANDLE hCurrentProc;

+    DWORD dwMessageId;

 

     error_occurred = FALSE;

 

     symbol = NULL;

     hCaller = NULL;

     hModule = GetModuleHandle( NULL );

-    hCurrentProc = GetCurrentProcess( );

+    dwMessageId = 0;

 

     if( handle == RTLD_DEFAULT )

     {

@@ -387,10 +460,16 @@ void *dlsym( void *handle, const char *name )
          * The next object is the one found upon the application of a load

          * order symbol resolution algorithm. To get caller function of dlsym()

          * use _ReturnAddress() intrinsic. To get HMODULE of caller function

-         * use standard GetModuleHandleExA() function.

+         * use MyGetModuleHandleFromAddress() which calls either standard

+         * GetModuleHandleExA() function or hack via VirtualQuery().

          */

-        if( !GetModuleHandleExA( GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS | GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT, (LPCSTR) _ReturnAddress( ), &hCaller ) )

+        hCaller = MyGetModuleHandleFromAddress( _ReturnAddress( ) );

+

+        if( hCaller == NULL )

+        {

+            dwMessageId = ERROR_INVALID_PARAMETER;

             goto end;

+        }

     }

 

     if( handle != RTLD_NEXT )

@@ -407,11 +486,14 @@ void *dlsym( void *handle, const char *name )
 

     if( hModule == handle || handle == RTLD_NEXT )

     {

+        HANDLE hCurrentProc;

         HMODULE *modules;

         DWORD cbNeeded;

         DWORD dwSize;

         size_t i;

 

+        hCurrentProc = GetCurrentProcess( );

+

         /* GetModuleHandle( NULL ) only returns the current program file. So

          * if we want to get ALL loaded module including those in linked DLLs,

          * we have to use EnumProcessModules( ).

@@ -447,7 +529,7 @@ void *dlsym( void *handle, const char *name )
             }

             else

             {

-                SetLastError( ERROR_NOT_ENOUGH_MEMORY );

+                dwMessageId = ERROR_NOT_ENOUGH_MEMORY;

                 goto end;

             }

         }

@@ -456,9 +538,9 @@ void *dlsym( void *handle, const char *name )
 end:

     if( symbol == NULL )

     {

-        if( GetLastError() == 0 )

-            SetLastError( ERROR_PROC_NOT_FOUND );

-        save_err_str( name );

+        if( !dwMessageId )

+            dwMessageId = ERROR_PROC_NOT_FOUND;

+        save_err_str( name, dwMessageId );

     }

 

     return *(void **) (&symbol);

@@ -617,7 +699,9 @@ static BOOL fill_info( void *addr, Dl_info *info )
     void *funcAddress = NULL;

 

     /* Get module of the specified address */

-    if( !GetModuleHandleExA( GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS | GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT, addr, &hModule ) || hModule == NULL )

+    hModule = MyGetModuleHandleFromAddress( addr );

+

+    if( hModule == NULL )

         return FALSE;

 

     dwSize = GetModuleFileNameA( hModule, module_filename, sizeof( module_filename ) );

@@ -655,7 +739,9 @@ int dladdr( void *addr, Dl_info *info )
         HMODULE hModule;

 

         /* Get module of the import thunk address */

-        if( !GetModuleHandleExA( GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS | GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT, addr, &hModule ) || hModule == NULL )

+        hModule = MyGetModuleHandleFromAddress( addr );

+

+        if( hModule == NULL )

             return 0;

 

         if( !get_image_section( hModule, IMAGE_DIRECTORY_ENTRY_IAT, &iat, &iatSize ) )

diff --git a/tests/test.c b/tests/test.c
index 132ede6..1d0d437 100644
--- a/tests/test.c
+++ b/tests/test.c
@@ -342,7 +342,7 @@ int main()
     *(void **) (&fwrite_local) = dlsym( global, "fwrite" );

     if (!fwrite_local)

     {

-        error = dlerror();

+        error = dlerror( );

         printf("ERROR\tCould not get symbol from global handle: %s\n",

             error ? error : "");

         CLOSE_LIB;

@@ -360,7 +360,7 @@ int main()
     *(void **) (&fputs_default) = dlsym( RTLD_DEFAULT, "fputs" );

     if (!fputs_default)

     {

-        error = dlerror();

+        error = dlerror( );

         printf("ERROR\tCould not get symbol from default handle: %s\n",

             error ? error : "");

         CLOSE_LIB;

@@ -623,7 +623,7 @@ int main()
     *(void **) (&function) = dlsym( global, "fwrite" );

     if (!function)

     {

-        error = dlerror();

+        error = dlerror( );

         printf("ERROR\tCould not get symbol from global handle: %s\n",

             error ? error : "");

         CLOSE_LIB;

@@ -659,7 +659,7 @@ int main()
     *(void **) (&function) = dlsym( global, "function3" );

     if (!function)

     {

-        error = dlerror();

+        error = dlerror( );

         printf("ERROR\tCould not get symbol from global handle: %s\n",

             error ? error : "");

         CLOSE_LIB;