diff mbox series

[v4,2/9] Windows gdb: Use allocated buffer for CONTEXT

Message ID 20260930151403.774660-2-ssbssa@yahoo.de
State New
Headers
Series [v4,1/9] gdb/testsuite: Add Windows replacement for aligned_alloc |

Commit Message

Hannes Domani Sept. 30, 2026, 3:11 p.m. UTC 
  This is done in preparation for the XState functions, because the
extended registers are stored directly after the CONTEXT, and its actual
size depends on the available XState features.

Approved-By: Tom Tromey <tom@tromey.com>
---
v3:
  - fixed missing newline
  - merged initialize_context into the windows_process_info constructor
v4: no changes
---
 gdb/aarch64-windows-nat.c      | 16 ++++++++--------
 gdb/nat/windows-nat.c          | 22 ++++++++++++++++++++++
 gdb/nat/windows-nat.h          | 20 +++++++++-----------
 gdbserver/win32-aarch64-low.cc | 10 +++++-----
 4 files changed, 44 insertions(+), 24 deletions(-)
diff mbox series

Patch

diff --git a/gdb/aarch64-windows-nat.c b/gdb/aarch64-windows-nat.c
index ff2c9762467..630704a8caf 100644
--- a/gdb/aarch64-windows-nat.c
+++ b/gdb/aarch64-windows-nat.c
@@ -185,7 +185,7 @@  aarch64_windows_nat_target::cleanup_windows_arch ()
 void
 aarch64_windows_per_inferior::fill_thread_context (windows_thread_info *th)
 {
-  CONTEXT *context = &th->context;
+  CONTEXT *context = th->context;
 
   if (context->ContextFlags == 0)
     {
@@ -199,7 +199,7 @@  aarch64_windows_per_inferior::fill_thread_context (windows_thread_info *th)
 void
 aarch64_windows_per_inferior::invalidate_thread_context (windows_thread_info *th)
 {
-  CONTEXT *context = &th->context;
+  CONTEXT *context = th->context;
   context->ContextFlags = 0;
 }
 
@@ -209,7 +209,7 @@  void
 aarch64_windows_nat_target::thread_context_continue (windows_thread_info *th,
 						     int killed)
 {
-  CONTEXT *context = &th->context;
+  CONTEXT *context = th->context;
 
   if (th->debug_registers_changed)
     {
@@ -250,9 +250,9 @@  aarch64_windows_nat_target::thread_context_step (windows_thread_info *th,
 						 bool enable)
 {
   if (enable)
-    th->context.Cpsr |= 0x200000;
+    th->context->Cpsr |= 0x200000;
   else
-    th->context.Cpsr &= ~0x200000;
+    th->context->Cpsr &= ~0x200000;
 }
 
 /* See windows-nat.h.  */
@@ -263,7 +263,7 @@  aarch64_windows_nat_target::fetch_one_register (struct regcache *regcache,
 {
   gdb_assert (r >= 0);
 
-  char *context_ptr = (char *) &th->context;
+  char *context_ptr = (char *) th->context;
   char *context_offset = context_ptr + aarch64_windows_process.mappings[r];
   struct gdbarch *gdbarch = regcache->arch ();
 
@@ -292,9 +292,9 @@  aarch64_windows_nat_target::store_one_register (const struct regcache *regcache,
 						windows_thread_info *th, int r)
 {
   gdb_assert (r >= 0);
-  gdb_assert (th->context.ContextFlags != 0);
+  gdb_assert (th->context->ContextFlags != 0);
 
-  char *context_ptr = (char *) &th->context;
+  char *context_ptr = (char *) th->context;
 
   regcache->raw_collect (r, context_ptr + aarch64_windows_process.mappings[r]);
 }
diff --git a/gdb/nat/windows-nat.c b/gdb/nat/windows-nat.c
index e975892f487..974b1d3535b 100644
--- a/gdb/nat/windows-nat.c
+++ b/gdb/nat/windows-nat.c
@@ -79,6 +79,28 @@  DeleteProcThreadAttributeList_ftype *DeleteProcThreadAttributeList;
   debug_prefixed_printf_cond (debug_events, "windows events", fmt, \
 			      ## __VA_ARGS__)
 
+windows_thread_info::windows_thread_info (windows_process_info *proc_,
+					  DWORD tid_, HANDLE h_, CORE_ADDR tlb)
+  : proc (proc_),
+    tid (tid_),
+    h (h_),
+    thread_local_base (tlb)
+{
+#ifdef __x86_64__
+  if (proc->wow64_process)
+    {
+      context_buffer.reset (xmalloc (sizeof (WOW64_CONTEXT)));
+      wow64_context = (WOW64_CONTEXT *) context_buffer.get ();
+    }
+  else
+#endif
+    {
+      context_buffer.reset (xmalloc (sizeof (CONTEXT)));
+      context = (CONTEXT *) context_buffer.get ();
+    }
+  *proc->context_flags_ptr (this) = 0;
+}
+
 void
 windows_thread_info::suspend ()
 {
diff --git a/gdb/nat/windows-nat.h b/gdb/nat/windows-nat.h
index fcdf43e270e..c153ad2c82c 100644
--- a/gdb/nat/windows-nat.h
+++ b/gdb/nat/windows-nat.h
@@ -63,13 +63,7 @@  enum stopping_kind
 struct windows_thread_info
 {
   windows_thread_info (windows_process_info *proc_,
-		       DWORD tid_, HANDLE h_, CORE_ADDR tlb)
-    : proc (proc_),
-      tid (tid_),
-      h (h_),
-      thread_local_base (tlb)
-  {
-  }
+		       DWORD tid_, HANDLE h_, CORE_ADDR tlb);
 
   DISABLE_COPY_AND_ASSIGN (windows_thread_info);
 
@@ -182,9 +176,9 @@  struct windows_thread_info
   /* The context of the thread, including any manipulations.  */
   union
   {
-    CONTEXT context {};
+    CONTEXT *context = nullptr;
 #ifdef __x86_64__
-    WOW64_CONTEXT wow64_context;
+    WOW64_CONTEXT *wow64_context;
 #endif
   };
 
@@ -203,6 +197,10 @@  struct windows_thread_info
 
   /* The name of the thread.  */
   gdb::unique_xmalloc_ptr<char> name;
+
+  /* The buffer for the thread context, including any XState registers if
+     available.  */
+  gdb::unique_xmalloc_ptr<void> context_buffer;
 };
 
 enum handle_exception_result
@@ -317,10 +315,10 @@  struct windows_process_info
   {
 #ifdef __x86_64__
     if (wow64_process)
-      return function (th != nullptr ? &th->wow64_context : nullptr);
+      return function (th != nullptr ? th->wow64_context : nullptr);
     else
 #endif
-      return function (th != nullptr ? &th->context : nullptr);
+      return function (th != nullptr ? th->context : nullptr);
   }
 
   DWORD *context_flags_ptr (windows_thread_info *th)
diff --git a/gdbserver/win32-aarch64-low.cc b/gdbserver/win32-aarch64-low.cc
index 5a7b72155db..e94548b6fef 100644
--- a/gdbserver/win32-aarch64-low.cc
+++ b/gdbserver/win32-aarch64-low.cc
@@ -169,7 +169,7 @@  aarch64_initial_stuff (process_info *proc)
 static void
 aarch64_get_thread_context (windows_thread_info *th)
 {
-  CONTEXT *context = &th->context;
+  CONTEXT *context = th->context;
 
   context->ContextFlags = (WindowsContext<decltype(context)>::full
 			   | WindowsContext<decltype(context)>::floating
@@ -193,7 +193,7 @@  aarch64_prepare_to_resume (windows_thread_info *th)
     {
       win32_require_context (th);
 
-      CONTEXT *context = &th->context;
+      CONTEXT *context = th->context;
 
       for (int i = 0; i < aarch64_num_bp_regs; i++)
 	{
@@ -223,7 +223,7 @@  aarch64_thread_added (windows_thread_info *th)
 static void
 aarch64_single_step (windows_thread_info *th)
 {
-  th->context.Cpsr |= 0x200000;
+  th->context->Cpsr |= 0x200000;
 }
 
 /* An array of offset mappings into a Win32 Context structure.
@@ -322,7 +322,7 @@  aarch64_fetch_inferior_register (struct regcache *regcache,
   int mappings_count;
   get_mappings (mappings, mappings_count);
 
-  char *context_ptr = (char *) &th->context;
+  char *context_ptr = (char *) th->context;
   char *context_offset;
   if (r < mappings_count)
     context_offset = context_ptr + mappings[r];
@@ -341,7 +341,7 @@  aarch64_store_inferior_register (struct regcache *regcache,
   int mappings_count;
   get_mappings (mappings, mappings_count);
 
-  char *context_ptr = (char *) &th->context;
+  char *context_ptr = (char *) th->context;
   char *context_offset;
   if (r < mappings_count)
     context_offset = context_ptr + mappings[r];