6 files changed, 144 insertions, 112 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 48945b2..a13cf99 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -63,6 +63,8 @@ if (BUILD_TESTS)
   enable_testing()
   add_library(testdll SHARED testdll.c)
   set_target_properties(testdll PROPERTIES PREFIX "")
+  add_library(testdll3 SHARED testdll3.c)
+  set_target_properties(testdll3 PROPERTIES PREFIX "")
   add_executable(t_dlfcn test.c)
   target_link_libraries(t_dlfcn dl)
   add_test (NAME t_dlfcn COMMAND t_dlfcn)
diff --git a/Makefile b/Makefile
index c02dce0..a0f5cb9 100644
--- a/Makefile
+++ b/Makefile
@@ -66,7 +66,10 @@ test.exe: test.o $(TARGETS)
 testdll.dll: testdll.c

         $(CC) -shared -o $@ $^

 

-test: $(TARGETS) test.exe testdll.dll

+testdll3.dll: testdll3.c

+        $(CC) -shared -o $@ $^

+

+test: $(TARGETS) test.exe testdll.dll testdll3.dll

         $(WINE) test.exe

 

 clean::

@@ -74,7 +77,7 @@ clean::
                 dlfcn.o \

                 libdl.dll libdl.a libdl.def libdl.dll.a libdl.lib libdl.exp \

                 tmptest.c tmptest.dll \

-                test.exe testdll.dll

+                test.exe testdll.dll testdll3.dll

 

 distclean: clean

         rm -f config.mak

diff --git a/cmake-test/CMakeLists.txt b/cmake-test/CMakeLists.txt
index 532f2b8..b853920 100644
--- a/cmake-test/CMakeLists.txt
+++ b/cmake-test/CMakeLists.txt
@@ -8,6 +8,8 @@ find_package(dlfcn-win32 REQUIRED)
 
 add_library(testdll SHARED ../testdll.c)
 set_target_properties(testdll PROPERTIES PREFIX "")
+add_library(testdll3 SHARED ../testdll3.c)
+set_target_properties(testdll3 PROPERTIES PREFIX "")
 add_executable(t_dlfcn ../test.c)
 target_link_libraries(t_dlfcn dlfcn-win32::dl)
 enable_testing()
diff --git a/dlfcn.c b/dlfcn.c
index b356558..1e706f0 100644
--- a/dlfcn.c
+++ b/dlfcn.c
@@ -2,6 +2,7 @@
  * dlfcn-win32

  * Copyright (c) 2007 Ramiro Polla

  * Copyright (c) 2015 Tiancheng "Timothy" Gu

+ * Copyright (c) 2019 Pali Rohár <pali.rohar@gmail.com>

  *

  * dlfcn-win32 is free software; you can redistribute it and/or

  * modify it under the terms of the GNU Lesser General Public

@@ -52,57 +53,48 @@
  * any kind of thread safety.

  */

 

-typedef struct global_object {

+typedef struct local_object {

     HMODULE hModule;

-    struct global_object *previous;

-    struct global_object *next;

-} global_object;

+    struct local_object *previous;

+    struct local_object *next;

+} local_object;

 

-static global_object first_object;

-static global_object first_automatic_object;

-static int auto_ref_count = 0;

+static local_object first_object;

 

-/* These functions implement a double linked list for the global objects. */

-static global_object *global_search( global_object *start, HMODULE hModule )

+/* These functions implement a double linked list for the local objects. */

+static local_object *local_search( HMODULE hModule )

 {

-    global_object *pobject;

+    local_object *pobject;

 

     if( hModule == NULL )

         return NULL;

 

-    for( pobject = start; pobject; pobject = pobject->next )

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

         if( pobject->hModule == hModule )

             return pobject;

 

     return NULL;

 }

 

-static void global_add( global_object *start, HMODULE hModule )

+static void local_add( HMODULE hModule )

 {

-    global_object *pobject;

-    global_object *nobject;

+    local_object *pobject;

+    local_object *nobject;

 

     if( hModule == NULL )

         return;

 

-    pobject = global_search( start, hModule );

+    pobject = local_search( hModule );

 

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

     if( pobject )

         return;

 

-    if( start == &first_automatic_object )

-    {

-        pobject = global_search( &first_object, hModule );

-        if( pobject )

-            return;

-    }

-

-    for( pobject = start; pobject->next; pobject = pobject->next );

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

 

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

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

 

-    /* Should this be enough to fail global_add, and therefore also fail

+    /* Should this be enough to fail local_add, and therefore also fail

      * dlopen?

      */

     if( !nobject )

@@ -114,14 +106,14 @@ static void global_add( global_object *start, HMODULE hModule )
     nobject->hModule = hModule;

 }

 

-static void global_rem( global_object *start, HMODULE hModule )

+static void local_rem( HMODULE hModule )

 {

-    global_object *pobject;

+    local_object *pobject;

 

     if( hModule == NULL )

         return;

 

-    pobject = global_search( start, hModule );

+    pobject = local_search( hModule );

 

     if( !pobject )

         return;

@@ -224,10 +216,6 @@ void *dlopen( const char *file, int mode )
 

     if( file == 0 )

     {

-        HMODULE hAddtnlMods[1024]; // Already loaded modules

-        HANDLE hCurrentProc = GetCurrentProcess( );

-        DWORD cbNeeded;

-

         /* POSIX says that if the value of file is 0, 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

@@ -242,27 +230,13 @@ void *dlopen( const char *file, int mode )
 

         if( !hModule )

             save_err_ptr_str( file );

-

-

-        /* 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( ).

-         */

-        if( EnumProcessModules( hCurrentProc, hAddtnlMods,

-            sizeof( hAddtnlMods ), &cbNeeded ) != 0 )

-        {

-            DWORD i;

-            for( i = 0; i < cbNeeded / sizeof( HMODULE ); i++ )

-            {

-                global_add( &first_automatic_object, hAddtnlMods[i] );

-            }

-        }

-        auto_ref_count++;

     }

     else

     {

+        HANDLE hCurrentProc;

+        DWORD dwProcModsBefore, dwProcModsAfter;

         CHAR lpFileName[MAX_PATH];

-        int i;

+        size_t i;

 

         /* MSDN says backslashes *must* be used instead of forward slashes. */

         for( i = 0 ; i < sizeof(lpFileName) - 1 ; i ++ )

@@ -276,6 +250,11 @@ void *dlopen( const char *file, int mode )
         }

         lpFileName[i] = '\0';

 

+        hCurrentProc = GetCurrentProcess( );

+

+        if( EnumProcessModules( hCurrentProc, NULL, 0, &dwProcModsBefore ) == 0 )

+            dwProcModsBefore = 0;

+

         /* POSIX says the search path is implementation-defined.

          * LOAD_WITH_ALTERED_SEARCH_PATH is used to make it behave more closely

          * to UNIX's search paths (start with system folders instead of current

@@ -284,17 +263,24 @@ void *dlopen( const char *file, int mode )
         hModule = LoadLibraryEx(lpFileName, NULL, 

                                 LOAD_WITH_ALTERED_SEARCH_PATH );

 

-        /* If the object was loaded with RTLD_GLOBAL, add it to list of global

-         * objects, so that its symbols may be retrieved even if the handle for

+        if( EnumProcessModules( hCurrentProc, NULL, 0, &dwProcModsAfter ) == 0 )

+            dwProcModsAfter = 0;

+

+        /* If the object was loaded with RTLD_LOCAL, add it to list of local

+         * objects, so that its symbols cannot be retrieved even if the handle for

          * the original program file is passed. POSIX says that if the same

          * file is specified in multiple invocations, and any of them are

          * RTLD_GLOBAL, even if any further invocations use RTLD_LOCAL, the

-         * symbols will remain global.

+         * symbols will remain global. If number of loaded modules was not

+         * changed after calling LoadLibraryEx(), it means that library was

+         * already loaded.

          */

         if( !hModule )

             save_err_str( lpFileName );

-        else if( (mode & RTLD_GLOBAL) )

-            global_add( &first_object, hModule );

+        else if( (mode & RTLD_LOCAL) && dwProcModsBefore != dwProcModsAfter )

+            local_add( hModule );

+        else if( !(mode & RTLD_LOCAL) && dwProcModsBefore == dwProcModsAfter )

+            local_rem( hModule );

     }

 

     /* Return to previous state of the error-mode bit flags. */

@@ -303,21 +289,6 @@ void *dlopen( const char *file, int mode )
     return (void *) hModule;

 }

 

-static void free_auto( )

-{

-    global_object *pobject = first_automatic_object.next;

-    if( pobject )

-    {

-        global_object *next;

-        for ( ; pobject; pobject = next )

-        {

-            next = pobject->next;

-            free( pobject );

-        }

-        first_automatic_object.next = NULL;

-    }

-}

-

 int dlclose( void *handle )

 {

     HMODULE hModule = (HMODULE) handle;

@@ -327,22 +298,11 @@ int dlclose( void *handle )
 

     ret = FreeLibrary( hModule );

 

-    /* If the object was loaded with RTLD_GLOBAL, remove it from list of global

+    /* If the object was loaded with RTLD_LOCAL, remove it from list of local

      * objects.

      */

     if( ret )

-    {

-        HMODULE cur = GetModuleHandle( NULL );

-        global_rem( &first_object, hModule );

-        if( hModule == cur )

-        {

-            auto_ref_count--;

-            if( auto_ref_count < 0 )

-                auto_ref_count = 0;

-            if( !auto_ref_count )

-                free_auto( );

-        }

-    }

+        local_rem( hModule );

     else

         save_err_ptr_str( handle );

 

@@ -356,6 +316,7 @@ void *dlsym( void *handle, const char *name )
 {

     FARPROC symbol;

     HMODULE hModule;

+    HANDLE hCurrentProc;

 

 #ifdef UNICODE

     wchar_t namew[MAX_PATH];

@@ -363,6 +324,7 @@ void *dlsym( void *handle, const char *name )
 #endif

 

     current_error = NULL;

+    hCurrentProc = GetCurrentProcess( );

 

     symbol = GetProcAddress( (HMODULE) handle, name );

 

@@ -377,25 +339,33 @@ void *dlsym( void *handle, const char *name )
 

     if( hModule == handle )

     {

-        global_object *pobject;

-

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

-        {

-            if( pobject->hModule )

-            {

-                symbol = GetProcAddress( pobject->hModule, name );

-                if( symbol != NULL )

-                    goto end;

-            }

-        }

+        HMODULE *modules;

+        DWORD cbNeeded;

+        DWORD dwSize;

+        size_t i;

 

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

+        /* 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( ).

+         */

+        if( EnumProcessModules( hCurrentProc, NULL, 0, &dwSize ) != 0 )

         {

-            if( pobject->hModule )

+            modules = malloc( dwSize );

+            if( modules )

             {

-                symbol = GetProcAddress( pobject->hModule, name );

-                if( symbol != NULL )

-                    goto end;

+                if( EnumProcessModules( hCurrentProc, modules, dwSize, &cbNeeded ) != 0 && dwSize == cbNeeded )

+                {

+                    for( i = 0; i < dwSize / sizeof( HMODULE ); i++ )

+                    {

+                        if( local_search( modules[i] ) )

+                            continue;

+                        symbol = GetProcAddress( modules[i], name );

+                        if( symbol != NULL )

+                            goto end;

+                    }

+

+                }

+                free( modules );

             }

         }

     }

@@ -472,18 +442,8 @@ char *dlerror( void )
 BOOL WINAPI DllMain( HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved )

 {

     (void) hinstDLL;

-    /*

-     * https://msdn.microsoft.com/en-us/library/windows/desktop/ms682583(v=vs.85).aspx 

-     *

-     *     When handling DLL_PROCESS_DETACH, a DLL should free resources such as heap

-     *     memory only if the DLL is being unloaded dynamically (the lpReserved

-     *     parameter is NULL).

-     */

-    if( fdwReason == DLL_PROCESS_DETACH && !lpvReserved )

-    {

-        auto_ref_count = 0;

-        free_auto( );

-    }

+    (void) fdwReason;

+    (void) lpvReserved;

     return TRUE;

 }

 #endif

diff --git a/test.c b/test.c
index ba440da..10c655e 100644
--- a/test.c
+++ b/test.c
@@ -2,6 +2,7 @@
  * dlfcn-win32

  * Copyright (c) 2007-2009 Ramiro Polla

  * Copyright (c) 2014      Tiancheng "Timothy" Gu

+ * Copyright (c) 2019      Pali Rohár <pali.rohar@gmail.com>

  *

  * dlfcn-win32 is free software; you can redistribute it and/or

  * modify it under the terms of the GNU Lesser General Public

@@ -25,6 +26,7 @@
 #endif

 #include <stdio.h>

 #include <string.h>

+#include <windows.h>

 #include "dlfcn.h"

 

 /* If these dlclose's fails, we don't care as the handles are going to be

@@ -77,6 +79,7 @@ int main()
     size_t (*fwrite_local) ( const void *, size_t, size_t, FILE * );

     int (*nonexistentfunction)( void );

     int ret;

+    HMODULE library3;

 

 #ifdef _DEBUG

     _CrtSetReportMode(_CRT_WARN, _CRTDBG_MODE_FILE);

@@ -335,6 +338,15 @@ int main()
         printf("SUCCESS\tGot symbol from global handle: %p\n", function);

     

 

+    library3 = LoadLibraryA("testdll3.dll");

+    if (!library3)

+    {

+        printf( "ERROR\tCould not open library3 via WINAPI\n" );

+        RETURN_ERROR;

+    }

+    else

+        printf( "SUCCESS\tOpened library3 via WINAPI: %p\n", library3 );

+

     ret = dlclose( library );

     if( ret )

     {

@@ -346,6 +358,21 @@ int main()
     else

         printf( "SUCCESS\tClosed library.\n" );

 

+    function = dlsym(global, "function3");

+    if (!function)

+    {

+        error = dlerror();

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

+            error ? error : "");

+        CLOSE_LIB;

+        CLOSE_GLOBAL;

+        RETURN_ERROR;

+    }

+    else

+        printf("SUCCESS\tGot symbol from global handle: %p\n", function);

+

+    RUNFUNC;

+

     ret = dlclose( global );

     if( ret )

     {

diff --git a/testdll3.c b/testdll3.c
new file mode 100644
index 0000000..3906e48
--- /dev/null
+++ b/testdll3.c
@@ -0,0 +1,38 @@
+/*

+ * dlfcn-win32

+ * Copyright (c) 2007 Ramiro Polla

+ * Copyright (c) 2019 Pali Rohár <pali.rohar@gmail.com>

+ *

+ * dlfcn-win32 is free software; you can redistribute it and/or

+ * modify it under the terms of the GNU Lesser General Public

+ * License as published by the Free Software Foundation; either

+ * version 2.1 of the License, or (at your option) any later version.

+ *

+ * dlfcn-win32 is distributed in the hope that it will be useful,

+ * but WITHOUT ANY WARRANTY; without even the implied warranty of

+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

+ * Lesser General Public License for more details.

+ *

+ * You should have received a copy of the GNU Lesser General Public

+ * License along with dlfcn-win32; if not, write to the Free Software

+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

+ */

+

+#ifdef _DEBUG

+#define _CRTDBG_MAP_ALLOC

+#include <stdlib.h>

+#include <crtdbg.h>

+#endif

+#include <stdio.h>

+

+#if defined(_WIN32)

+#define EXPORT __declspec(dllexport)

+#else

+#define EXPORT

+#endif

+

+EXPORT int function3( void )

+{

+    printf( "Hello, world!\n" );

+    return 0;

+}