From 6ddd6e836cf0c1f592845296428dde28df851e50 Mon Sep 17 00:00:00 2001
From: Alexandre Julliard <julliard@winehq.org>
Date: Tue, 8 Dec 2020 12:46:17 +0100
Subject: [PATCH] ntdll: Support the Android Java %fs register being a GDT
 selector.

Signed-off-by: Alexandre Julliard <julliard@winehq.org>
---
 dlls/ntdll/unix/loader.c      | 1 +
 dlls/wineandroid.drv/device.c | 4 +++-
 dlls/wineandroid.drv/init.c   | 2 ++
 3 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/dlls/ntdll/unix/loader.c b/dlls/ntdll/unix/loader.c
index 676027fe516..31cfb43d11f 100644
--- a/dlls/ntdll/unix/loader.c
+++ b/dlls/ntdll/unix/loader.c
@@ -1671,6 +1671,7 @@ static jstring wine_init_jni( JNIEnv *env, jobject obj, jobjectArray cmdline, jo
     {
         unsigned short java_fs;
         __asm__( "mov %%fs,%0" : "=r" (java_fs) );
+        if (!(java_fs & 4)) java_gdt_sel = java_fs;
         __asm__( "mov %0,%%fs" :: "r" (0) );
         start_main_thread();
         __asm__( "mov %0,%%fs" :: "r" (java_fs) );
diff --git a/dlls/wineandroid.drv/device.c b/dlls/wineandroid.drv/device.c
index 45ceb0a5c0b..5bebc5c7901 100644
--- a/dlls/wineandroid.drv/device.c
+++ b/dlls/wineandroid.drv/device.c
@@ -258,9 +258,11 @@ static inline void wrap_java_call(void)   { __asm__( "mov %0,%%fs" :: "r" (java_
 static inline void unwrap_java_call(void) { __asm__( "mov %0,%%fs" :: "r" (orig_fs) ); }
 static inline void init_java_thread( JavaVM *java_vm )
 {
+    java_fs = *p_java_gdt_sel;
     __asm__( "mov %%fs,%0" : "=r" (orig_fs) );
+    __asm__( "mov %0,%%fs" :: "r" (java_fs) );
     (*java_vm)->AttachCurrentThread( java_vm, &jni_env, 0 );
-    __asm__( "mov %%fs,%0" : "=r" (java_fs) );
+    if (!*p_java_gdt_sel) __asm__( "mov %%fs,%0" : "=r" (java_fs) );
     __asm__( "mov %0,%%fs" :: "r" (orig_fs) );
 }
 
diff --git a/dlls/wineandroid.drv/init.c b/dlls/wineandroid.drv/init.c
index 638fb5726c1..d6ca79a1416 100644
--- a/dlls/wineandroid.drv/init.c
+++ b/dlls/wineandroid.drv/init.c
@@ -622,6 +622,7 @@ static void load_android_libs(void)
 
 JavaVM **p_java_vm = NULL;
 jobject *p_java_object = NULL;
+unsigned short *p_java_gdt_sel = NULL;
 
 static BOOL process_attach(void)
 {
@@ -635,6 +636,7 @@ static BOOL process_attach(void)
 
     p_java_vm = dlsym( ntdll, "java_vm" );
     p_java_object = dlsym( ntdll, "java_object" );
+    p_java_gdt_sel = dlsym( ntdll, "java_gdt_sel" );
 
     object = *p_java_object;