X86: Move the GDT down to where it can be accessed in 32 bit mode.

The GDT can be accessed by user level software running in compatibility mode
by moving segment selectors into segment registers. The GDT needs to be set up
at an address accessible in this mode.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/arch/x86/process.cc b/src/arch/x86/process.cc
index 088a0661c..cce8e3a3d 100644
--- a/src/arch/x86/process.cc
+++ b/src/arch/x86/process.cc
@@ -132,7 +132,7 @@ I386LiveProcess::I386LiveProcess(LiveProcessParams *params,
         int _numSyscallDescs) :
     X86LiveProcess(params, objFile, _syscallDescs, _numSyscallDescs)
 {
-    _gdtStart = ULL(0x100000000);
+    _gdtStart = ULL(0xffffd000);
     _gdtSize = VMPageSize;
 
     vsyscallPage.base = 0xffffe000ULL;
@@ -140,7 +140,7 @@ I386LiveProcess::I386LiveProcess(LiveProcessParams *params,
     vsyscallPage.vsyscallOffset = 0x400;
     vsyscallPage.vsysexitOffset = 0x410;
 
-    stack_base = vsyscallPage.base;
+    stack_base = _gdtStart;
 
     // Set pointer for next thread stack.  Reserve 8M for main stack.
     next_thread_stack_base = stack_base - (8 * 1024 * 1024);