Implement access to AVX registers on Windows

Author: ssbssa

gdb/amd64-windows-nat.c

@@ -86,6 +86,9 @@ const int amd64_mappings[] =
 };
 #undef context_offset
 
+const int amd64_mappings_count
+  = sizeof (amd64_mappings) / sizeof (amd64_mappings[0]);
+
 /* segment_register_p_ftype implementation for amd64.  */
 
 int

gdb/i386-windows-nat.c

@@ -74,6 +74,9 @@ const int i386_mappings[] =
 #undef context_offset
 #undef CONTEXT
 
+const int i386_mappings_count
+  = sizeof (i386_mappings) / sizeof (i386_mappings[0]);
+
 /* segment_register_p_ftype implementation for x86.  */
 
 int

gdb/nat/windows-nat.c

@@ -20,6 +20,7 @@
 #include "gdbsupport/common-debug.h"
 #include "gdbsupport/xml-utils.h"
 #include "target/target.h"
+#include "gdbsupport/x86-xstate.h"
 
 #undef GetModuleFileNameEx
 
@@ -72,6 +73,17 @@ InitializeProcThreadAttributeList_ftype *InitializeProcThreadAttributeList;
 UpdateProcThreadAttribute_ftype *UpdateProcThreadAttribute;
 DeleteProcThreadAttributeList_ftype *DeleteProcThreadAttributeList;
 
+GetEnabledXStateFeatures_ftype *GetEnabledXStateFeatures;
+InitializeContext_ftype *InitializeContext;
+GetXStateFeaturesMask_ftype *GetXStateFeaturesMask;
+SetXStateFeaturesMask_ftype *SetXStateFeaturesMask;
+LocateXStateFeature_ftype *LocateXStateFeature;
+#ifdef __x86_64__
+RtlGetExtendedFeaturesMask_ftype *RtlGetExtendedFeaturesMask;
+RtlSetExtendedFeaturesMask_ftype *RtlSetExtendedFeaturesMask;
+RtlLocateExtendedFeature_ftype *RtlLocateExtendedFeature;
+#endif
+
 /* Note that 'debug_events' must be locally defined in the relevant
    functions.  */
 #define DEBUG_EVENTS(fmt, ...) \
@@ -241,10 +253,35 @@ windows_process_info::pid_to_exec_file (int pid)
   return path;
 }
 
-void windows_process_info::initialize_context (windows_thread_info *th)
+void windows_process_info::initialize_context (windows_thread_info *th,
+					       DWORD xstate_features)
 {
+  if (xstate_features != 0)
+    {
+      DWORD context_flags = with_context (nullptr, [] (auto *context)
+	{
+	  return WindowsContext<decltype(context)>::control;
+	});
+      context_flags |= CONTEXT_XSTATE_FLAG;
+      DWORD xstate_size = 0;
+      InitializeContext (NULL, context_flags, NULL, &xstate_size);
+      th->context_buffer.reset (xmalloc (xstate_size));
+      CONTEXT *context = nullptr;
+      if (!InitializeContext (th->context_buffer.get (),
+			      context_flags, &context, &xstate_size))
+	error ("InitializeContext failure %lu\n", GetLastError ());
 #ifdef __x86_64__
-  if (wow64_process)
+      /* InitializeContext actually initializes a WOW64_CONTEXT when
+	 context_flags contains a WOW64_CONTEXT_* value, so a cast is needed.
+	 */
+      if (wow64_process)
+	th->wow64_context = (WOW64_CONTEXT *) context;
+      else
+#endif
+	th->context = context;
+    }
+#ifdef __x86_64__
+  else if (wow64_process)
     {
       th->context_buffer.reset (xmalloc (sizeof (WOW64_CONTEXT)));
       th->wow64_context = (WOW64_CONTEXT *) th->context_buffer.get ();
@@ -1078,6 +1115,35 @@ disable_randomization_available ()
 
 /* See windows-nat.h.  */
 
+DWORD64
+get_xstate_features ()
+{
+  if (GetEnabledXStateFeatures != nullptr
+      && InitializeContext != nullptr
+      && GetXStateFeaturesMask != nullptr
+      && SetXStateFeaturesMask != nullptr
+      && LocateXStateFeature != nullptr
+#ifdef __x86_64__
+      && RtlGetExtendedFeaturesMask != nullptr
+      && RtlSetExtendedFeaturesMask != nullptr
+      && RtlLocateExtendedFeature != nullptr
+#endif
+  )
+    {
+      DWORD64 xstate_features
+	= GetEnabledXStateFeatures () & X86_XSTATE_ALL_MASK;
+      /* The extended xstate functions are only needed if the available
+	 features exceed SSE.  */
+      if ((xstate_features & ~X86_XSTATE_SSE_MASK) == 0)
+	xstate_features = 0;
+      return xstate_features;
+    }
+
+  return 0;
+}
+
+/* See windows-nat.h.  */
+
 bool
 initialize_loadable ()
 {
@@ -1108,6 +1174,12 @@ initialize_loadable ()
       GPA (hm, InitializeProcThreadAttributeList);
       GPA (hm, UpdateProcThreadAttribute);
       GPA (hm, DeleteProcThreadAttributeList);
+
+      GPA (hm, GetEnabledXStateFeatures);
+      GPA (hm, InitializeContext);
+      GPA (hm, GetXStateFeaturesMask);
+      GPA (hm, SetXStateFeaturesMask);
+      GPA (hm, LocateXStateFeature);
     }
 
   /* Set variables to dummy versions of these processes if the function
@@ -1173,6 +1245,16 @@ initialize_loadable ()
 	GPA (hm, GetThreadDescription);
     }
 
+#ifdef __x86_64__
+  hm = LoadLibrary (TEXT ("ntdll.dll"));
+  if (hm)
+    {
+      GPA (hm, RtlGetExtendedFeaturesMask);
+      GPA (hm, RtlSetExtendedFeaturesMask);
+      GPA (hm, RtlLocateExtendedFeature);
+    }
+#endif
+
 #undef GPA
 
   return result;

gdb/nat/windows-nat.h

@@ -35,6 +35,9 @@
 #define CONTEXT_EXTENDED_REGISTERS 0
 #endif
 
+#define CONTEXT_EXTENDED_REGISTERS_FLAG 0x20
+#define CONTEXT_XSTATE_FLAG		0x40
+
 namespace windows_nat
 {
 
@@ -258,7 +261,7 @@ struct windows_process_info
 
   const char *pid_to_exec_file (int);
 
-  void initialize_context (windows_thread_info *th);
+  void initialize_context (windows_thread_info *th, DWORD xstate_features);
 
   template<typename Function>
   auto with_context (windows_thread_info *th, Function function)
@@ -371,6 +374,14 @@ extern BOOL create_process (const wchar_t *image, wchar_t *command_line,
 #define InitializeProcThreadAttributeList dyn_InitializeProcThreadAttributeList
 #define UpdateProcThreadAttribute dyn_UpdateProcThreadAttribute
 #define DeleteProcThreadAttributeList dyn_DeleteProcThreadAttributeList
+#define GetEnabledXStateFeatures	dyn_GetEnabledXStateFeatures
+#define InitializeContext		dyn_InitializeContext
+#define GetXStateFeaturesMask		dyn_GetXStateFeaturesMask
+#define SetXStateFeaturesMask		dyn_SetXStateFeaturesMask
+#define LocateXStateFeature		dyn_LocateXStateFeature
+#define RtlGetExtendedFeaturesMask	dyn_RtlGetExtendedFeaturesMask
+#define RtlSetExtendedFeaturesMask	dyn_RtlSetExtendedFeaturesMask
+#define RtlLocateExtendedFeature	dyn_RtlLocateExtendedFeature
 
 typedef BOOL WINAPI (AdjustTokenPrivileges_ftype) (HANDLE, BOOL,
 						   PTOKEN_PRIVILEGES,
@@ -465,6 +476,33 @@ extern DeleteProcThreadAttributeList_ftype *DeleteProcThreadAttributeList;
 
 extern bool disable_randomization_available ();
 
+typedef DWORD64 (WINAPI GetEnabledXStateFeatures_ftype) ();
+extern GetEnabledXStateFeatures_ftype *GetEnabledXStateFeatures;
+
+typedef BOOL (WINAPI InitializeContext_ftype) (PVOID, DWORD,
+					       PCONTEXT*, PDWORD);
+extern InitializeContext_ftype *InitializeContext;
+
+typedef BOOL (WINAPI GetXStateFeaturesMask_ftype) (PCONTEXT, PDWORD64);
+extern GetXStateFeaturesMask_ftype *GetXStateFeaturesMask;
+
+typedef BOOL (WINAPI SetXStateFeaturesMask_ftype) (PCONTEXT, DWORD64);
+extern SetXStateFeaturesMask_ftype *SetXStateFeaturesMask;
+
+typedef PVOID (WINAPI LocateXStateFeature_ftype) (PCONTEXT, DWORD, PDWORD);
+extern LocateXStateFeature_ftype *LocateXStateFeature;
+
+#ifdef __x86_64__
+typedef DWORD64 (WINAPI RtlGetExtendedFeaturesMask_ftype) (PVOID);
+extern RtlGetExtendedFeaturesMask_ftype *RtlGetExtendedFeaturesMask;
+
+typedef VOID (WINAPI RtlSetExtendedFeaturesMask_ftype) (PVOID, DWORD64);
+extern RtlSetExtendedFeaturesMask_ftype *RtlSetExtendedFeaturesMask;
+
+typedef PVOID (WINAPI RtlLocateExtendedFeature_ftype) (PVOID, DWORD, PDWORD);
+extern RtlLocateExtendedFeature_ftype *RtlLocateExtendedFeature;
+#endif
+
 /* Helper classes to get the correct ContextFlags values based on the
    used type (CONTEXT or WOW64_CONTEXT).  */
 
@@ -528,16 +566,64 @@ enum_process_modules (CONTEXT *, HANDLE process,
   return EnumProcessModules (process, modules, size, needed);
 }
 
+static inline BOOL
+get_xstate_features_mask (CONTEXT *context, DWORD64 *mask)
+{
+  return GetXStateFeaturesMask (context, mask);
+}
+
+static inline BOOL
+set_xstate_features_mask (CONTEXT *context, DWORD64 mask)
+{
+  return SetXStateFeaturesMask (context, mask);
+}
+
+static inline PVOID
+locate_xstate_feature (CONTEXT *context, DWORD feature, DWORD *length)
+{
+  return LocateXStateFeature (context, feature, length);
+}
+
 #ifdef __x86_64__
 static inline BOOL
 get_thread_context (HANDLE h, WOW64_CONTEXT *context)
 {
+  if ((context->ContextFlags & CONTEXT_XSTATE_FLAG) != 0)
+    {
+      DWORD flags = context->ContextFlags;
+      context->ContextFlags &= ~CONTEXT_EXTENDED_REGISTERS_FLAG;
+      BOOL ret = Wow64GetThreadContext (h, context);
+      context->ContextFlags = flags;
+      if (!ret)
+	return FALSE;
+
+      context->ContextFlags &= ~CONTEXT_XSTATE_FLAG;
+      ret = Wow64GetThreadContext (h, context);
+      context->ContextFlags = flags;
+      return ret;
+    }
+
   return Wow64GetThreadContext (h, context);
 }
 
 static inline BOOL
 set_thread_context (HANDLE h, WOW64_CONTEXT *context)
 {
+  if ((context->ContextFlags & CONTEXT_XSTATE_FLAG) != 0)
+    {
+      DWORD flags = context->ContextFlags;
+      context->ContextFlags &= ~CONTEXT_EXTENDED_REGISTERS_FLAG;
+      BOOL ret = Wow64SetThreadContext (h, context);
+      context->ContextFlags = flags;
+      if (!ret)
+	return FALSE;
+
+      context->ContextFlags &= ~CONTEXT_XSTATE_FLAG;
+      ret = Wow64SetThreadContext (h, context);
+      context->ContextFlags = flags;
+      return ret;
+    }
+
   return Wow64SetThreadContext (h, context);
 }
 
@@ -555,8 +641,33 @@ enum_process_modules (WOW64_CONTEXT *, HANDLE process,
   return EnumProcessModulesEx (process, modules, size, needed,
 			       LIST_MODULES_32BIT);
 }
+
+static inline BOOL
+get_xstate_features_mask (WOW64_CONTEXT *context, DWORD64 *mask)
+{
+  *mask = RtlGetExtendedFeaturesMask (context + 1);
+  return TRUE;
+}
+
+static inline BOOL
+set_xstate_features_mask (WOW64_CONTEXT *context, DWORD64 mask)
+{
+  RtlSetExtendedFeaturesMask (context + 1, mask);
+  return TRUE;
+}
+
+static inline PVOID
+locate_xstate_feature (WOW64_CONTEXT *context, DWORD feature, DWORD *length)
+{
+  return RtlLocateExtendedFeature (context + 1, feature, length);
+}
 #endif
 
+/* Return the available xstate features, but only if there is more than SSE
+   available.  */
+
+extern DWORD64 get_xstate_features ();
+
 /* Load any functions which may not be available in ancient versions
    of Windows.  */