[PATCH v2] Fix WOW64 process system DLL paths
Hannes Domani
ssbssa@yahoo.de
Tue Mar 24 19:23:51 GMT 2020
GetModuleFileNameEx returns for some DLLs of WOW64 processes
the path inside the 64bit system directory instead of the 32bit
syswow64 directory.
Problem happens e.g. with dbghelp.dll:
(gdb) start
Temporary breakpoint 1 at 0x415a00: file fiber.cpp, line 430.
Starting program: C:\src\tests\fiber.exe
warning: `C:\Windows\system32\dbghelp.dll': Shared library architecture i386:x86-64 is not compatible with target architecture i386.
Temporary breakpoint 1, main () at fiber.cpp:430
430 {
(gdb) info sharedlibrary
>From To Syms Read Shared Object Library
0x77070000 0x771d4d20 Yes (*) C:\Windows\SysWOW64\ntdll.dll
0x74dc0000 0x74ebad9c Yes (*) C:\Windows\syswow64\kernel32.dll
0x75341000 0x75386a18 Yes (*) C:\Windows\syswow64\KernelBase.dll
0x6f6a1000 0x6f7c48fc Yes (*) C:\Windows\system32\dbghelp.dll
0x74d01000 0x74dab2c4 Yes (*) C:\Windows\syswow64\msvcrt.dll
(*): Shared library is missing debugging information.
This detects this situation and converts the DLL path to the
syswow64 equivalent.
gdb/ChangeLog:
2020-03-24 Hannes Domani <ssbssa@yahoo.de>
* windows-nat.c (windows_add_all_dlls): Fix system dll paths.
---
v2:
- added error check with gdb_assert's
- use std::string for newly assembled dll path
---
gdb/windows-nat.c | 44 +++++++++++++++++++++++++++++++++++++++++---
1 file changed, 41 insertions(+), 3 deletions(-)
diff --git a/gdb/windows-nat.c b/gdb/windows-nat.c
index 9c5ea5c046..8b7328946b 100644
--- a/gdb/windows-nat.c
+++ b/gdb/windows-nat.c
@@ -1993,16 +1993,39 @@ windows_add_all_dlls (void)
return;
}
+#ifdef __x86_64__
+ char system_dir[__PMAX];
+ char syswow_dir[__PMAX];
+ size_t system_dir_len = 0;
+ if (wow64_process)
+ {
+ UINT len = GetSystemDirectoryA (system_dir, sizeof (system_dir));
+ /* Error check. */
+ gdb_assert (len != 0);
+ /* Check that we have passed a large enough buffer. */
+ gdb_assert (len < sizeof (system_dir));
+
+ len = GetSystemWow64DirectoryA (syswow_dir, sizeof (syswow_dir));
+ /* Error check. */
+ gdb_assert (len != 0);
+ /* Check that we have passed a large enough buffer. */
+ gdb_assert (len < sizeof (syswow_dir));
+
+ strcat (system_dir, "\\");
+ strcat (syswow_dir, "\\");
+ system_dir_len = strlen (system_dir);
+ }
+#endif
for (i = 1; i < (int) (cb_needed / sizeof (HMODULE)); i++)
{
MODULEINFO mi;
#ifdef __USEWIDE
wchar_t dll_name[__PMAX];
- char name[__PMAX];
+ char dll_name_mb[__PMAX];
#else
char dll_name[__PMAX];
- char *name;
#endif
+ const char *name;
if (GetModuleInformation (current_process_handle, hmodules[i],
&mi, sizeof (mi)) == 0)
continue;
@@ -2010,10 +2033,25 @@ windows_add_all_dlls (void)
dll_name, sizeof (dll_name)) == 0)
continue;
#ifdef __USEWIDE
- wcstombs (name, dll_name, __PMAX);
+ wcstombs (dll_name_mb, dll_name, __PMAX);
+ name = dll_name_mb;
#else
name = dll_name;
#endif
+#ifdef __x86_64__
+ /* Convert the DLL path of WOW64 processes returned by
+ GetModuleFileNameEx from the 64bit system directory to the
+ 32bit syswow64 directory if necessary. */
+ std::string syswow_dll_path;
+ if (wow64_process
+ && strncasecmp (name, system_dir, system_dir_len) == 0
+ && strchr (name + system_dir_len, '\\') == nullptr)
+ {
+ syswow_dll_path = syswow_dir;
+ syswow_dll_path += name + system_dir_len;
+ name = syswow_dll_path.c_str();
+ }
+#endif
solib_end->next = windows_make_so (name, mi.lpBaseOfDll);
solib_end = solib_end->next;
--
2.25.2
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