[PATCH] loader: Implement setting of %gs for wine64

[mlankhorst]

---
 loader/pthread.c |   29 +++++++++++++++++++++++++++--
 1 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/loader/pthread.c b/loader/pthread.c
index 4951d97..3277846 100644
--- a/loader/pthread.c
+++ b/loader/pthread.c
@@ -48,10 +48,19 @@
 static int init_done;
 static int nb_threads = 1;
 
-#ifndef __i386__
+#if !defined(__i386__) && !defined(__x86_64__)
 static pthread_key_t teb_key;
 #endif
 
+#if defined(__x86_64__) && defined(__linux__)
+
+#include <asm/prctl.h>
+
+/* Helper function for arch_prctl */
+extern int arch_prctl(int func, void *ptr);
+
+#endif
+
 /***********************************************************************
  *           init_process
  *
@@ -125,7 +134,6 @@ static int create_thread( struct wine_pthread_thread_info *info )
     return ret;
 }
 
-
 /***********************************************************************
  *           init_current_teb
  *
@@ -135,12 +143,24 @@ static void init_current_teb( struct wine_pthread_thread_info *info )
 {
 #ifdef __i386__
     /* On the i386, the current thread is in the %fs register */
+    /* On x86_64, it's in %gs (but the functions here are called the same) */
     LDT_ENTRY fs_entry;
 
     wine_ldt_set_base( &fs_entry, info->teb_base );
     wine_ldt_set_limit( &fs_entry, info->teb_size - 1 );
     wine_ldt_set_flags( &fs_entry, WINE_LDT_FLAGS_DATA|WINE_LDT_FLAGS_32BIT );
     wine_ldt_init_fs( info->teb_sel, &fs_entry );
+#elif defined(__x86_64__) && defined(__linux__)
+    int ret;
+
+    /* Use the arch_prctl syscall to set the %gs selector to teb */
+    ret = arch_prctl(ARCH_SET_GS, info->teb_base);
+    if (ret < 0)
+        perror("Could not set %%gs:");
+#elif defined(__x86_64__)
+    /* All programs I've seen so far bomb out immediately if they can't
+     * manipulate %gs directly. Only winelib would work. */
+#error Please define setting %%gs for your architecture
 #else
     if (!init_done)  /* first thread */
         pthread_key_create( &teb_key, NULL );
@@ -174,6 +194,11 @@ static void *get_current_teb(void)
     void *ret;
     __asm__( ".byte 0x64\n\tmovl 0x18,%0" : "=r" (ret) );
     return ret;
+#elif defined(__x86_64__)
+    void *ret;
+    /* Teb == ((TEB *)%gs)->Tib.Self (at offset 0x30) */
+    __asm__( ".byte 0x65\n\tmovq 0x30,%0" : "=r" (ret) );
+    return ret;
 #else
     return pthread_getspecific( teb_key );
 #endif
-- 
1.5.6.5


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