[PATCH 0/1] MR3047: ntdll: hook mmap for force allocate low 32-bit memory on wow64

[Fan WenJie (＠fanwenjie)]

Signed-off-by: Fan WenJie

[PATCH 1/1] ntdll: hook mmap for force allocate low 32-bit memory on wow64

[Fan WenJie]

From: Fan WenJie

Signed-off-by: Fan WenJie 
---
 dlls/ntdll/unix/loader.c | 54 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 54 insertions(+)

diff --git a/dlls/ntdll/unix/loader.c b/dlls/ntdll/unix/loader.c
index 4d855a18cff..8f753f7e91b 100644
--- a/dlls/ntdll/unix/loader.c
+++ b/dlls/ntdll/unix/loader.c
@@ -35,6 +35,7 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <sys/mman.h>
+#include <sys/syscall.h>
 #include <sys/wait.h>
 #include <unistd.h>
 #include <dlfcn.h>
@@ -2378,6 +2379,13 @@ void __wine_main( int argc, char *argv[], char *envp[] )
             static char noexec[] = "WINELOADERNOEXEC=1";
             char **new_argv = malloc( (argc + 2) * sizeof(*argv) );

+#ifdef _WIN64
+            {
+                Dl_info info = { 0 };
+                dladdr(&__wine_main, &info);
+                setenv("LD_PRELOAD", info.dli_fname, 1);
+            }
+#endif
             memcpy( new_argv + 1, argv, (argc + 1) * sizeof(*argv) );
             putenv( noexec );
             loader_exec( new_argv, current_machine );
@@ -2400,3 +2408,49 @@ void __wine_main( int argc, char *argv[], char *envp[] )
 #endif
     start_main_thread();
 }
+
+#ifdef _WIN64
+
+#if MAP_32BIT
+
+void *mmap64(void *addr, size_t length, int prot, int flags, int fd, off64_t offset)
+{
+    return (void*)syscall(SYS_mmap, addr, length, prot, flags | MAP_32BIT, fd, offset);
+}
+
+void *mmap(void *addr, size_t length, int prot, int flags, int fd, off_t offset)
+{
+    return mmap64(addr, length, prot, flags, fd, offset);
+}
+
+#else
+
+void *mmap64(void *addr, size_t length, int prot, int flags, int fd, off64_t offset)
+{
+    if (wow_peb)
+    {
+        NtAllocateVirtualMemory(GetCurrentProcess(), &addr, 0xffffffff, &length, MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE);
+        flags |= MAP_FIXED;
+    }
+    return (void*)syscall(SYS_mmap, addr, length, prot, flags, fd, offset);
+}
+
+void *mmap(void *addr, size_t length, int prot, int flags, int fd, off_t offset)
+{
+    return mmap64(addr, length, prot, flags, fd, offset);
+}
+
+int munmap(void *addr, size_t length)
+{
+    int ret = (int)syscall(SYS_munmap, addr, length);
+    if (wow_peb)
+    {
+        length = 0;
+        NtFreeVirtualMemory(GetCurrentProcess(), &addr, &length, MEM_RELEASE);
+    }
+    return ret;
+}
+
+#endif
+
+#endif

[PATCH 1/1] ntdll: hook mmap for force allocate low 32-bit memory on wow64

[Marvin]

Hi,

It looks like your patch introduced the new failures shown below.
Please investigate and fix them before resubmitting your patch.
If they are not new, fixing them anyway would help a lot. Otherwise
please ask for the known failures list to be updated.

The tests also ran into some preexisting test failures. If you know how
to fix them that would be helpful. See the TestBot job for the details:

The full results can be found at:
https://testbot.winehq.org/JobDetails.pl?Key=133695

Your paranoid android.

=== debian11 (32 bit report) ===

user32:
msg.c:6897: Test failed: SetFocus(hwnd) on a button: 4: the msg 0x0007 was expected, but got msg 0x0005 instead
msg.c:6897: Test failed: SetFocus(hwnd) on a button: 5: the msg 0x0135 was expected, but got msg 0x030f instead
msg.c:6897: Test failed: SetFocus(hwnd) on a button: 6: the msg 0x0111 was expected, but got msg 0x001c instead
msg.c:6897: Test failed: SetFocus(hwnd) on a button: 7: the msg 0x8000 was expected, but got msg 0x0086 instead
msg.c:6897: Test failed: SetFocus(hwnd) on a button: 8: the msg sequence is not complete: expected 0000 - actual 0006

=== debian11b (64 bit WoW report) ===

ntdll:
virtual.c:1260: Test failed: CreateThread with huge stack failed

[Stefan Dösinger (＠stefan)]

I am not sure if we want to hook such a low level function unless we have no other choice.

E.g. for Vulkan maps the goal we have is something along the lines of https://github.com/KhronosGroup/Vulkan-Docs/pull/1906 . It would also be nice to handle this more flexibly than mapping everything < 4GB. A lot of allocations are never passed to the Windows application and many libraries that we use allow us to allocate memory first and then pass it to the library, instead of having the library return us some pointer.

MacOS allows us to create a second mapping for arbitrary memory. That's what CrossOver is using for glMapBuffer and friends. In hangover, I blocked every memory above 4GB (by blocking everything below 4GB, then calling mmap until it fails, and then releasing my < 4GB addresses again). Both of these options work but have their own problems.

MAP_32BIT puts the mapping below 2GB, not 4GB. We need the alternative codepath for e.g. arm64 hosts anyway, so I don't think we should bother about MAP_32BIT.

[Aida Jonikienė (＠DodoGTA)]

This change workarounds the graphical corruption issues in WineD3D (OpenGL) applications with WoW64 mode enabled

The non-MAP_32BIT code path triggers a `012c:err:unwind:segv_handler_early Got unexpected trap 14 during process initialization` error though (at least with wine-staging)

[PATCH 0/1] MR3047: ntdll: hook mmap for force allocate low 32-bit memory on wow64 - closed

[Fan WenJie (＠fanwenjie)]

This merge request was closed by Fan WenJie.