gdb/aarch64-windows-nat.c - binutils-gdb - Git at Google

 /* Native-dependent code for Windows AArch64.

    Copyright (C) 2025-2026 Free Software Foundation, Inc.

    This file is part of GDB.

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

 #include "windows-nat.h"
 #include "regcache.h"
 #include "gdbarch.h"
 #include "inferior.h"

 #include "aarch64-nat.h"

 using namespace windows_nat;

 struct aarch64_windows_per_inferior : public windows_per_inferior
 {
   aarch64_debug_reg_state dr_state;
 };

 struct aarch64_windows_nat_target final
   : public aarch64_nat_target<windows_nat_target>
 {
   std::vector<CORE_ADDR> stopped_data_addresses () override;
   bool stopped_by_watchpoint () override;

   void initialize_windows_arch (bool attaching) override;
   void cleanup_windows_arch () override;

   void fill_thread_context (windows_thread_info *th) override;

   void thread_context_continue (windows_thread_info *th, int killed) override;
   void thread_context_step (windows_thread_info *th) override;

   void fetch_one_register (struct regcache *regcache,
 			   windows_thread_info *th, int r) override;
   void store_one_register (const struct regcache *regcache,
 			   windows_thread_info *th, int r) override;

   bool is_sw_breakpoint (const EXCEPTION_RECORD *er) const override;
 };

 /* The current process.  */
 static aarch64_windows_per_inferior aarch64_windows_process;

 #define context_offset(x) (offsetof (CONTEXT, x))
 const int aarch64_mappings[] =
 {
   context_offset (X0),
   context_offset (X1),
   context_offset (X2),
   context_offset (X3),
   context_offset (X4),
   context_offset (X5),
   context_offset (X6),
   context_offset (X7),
   context_offset (X8),
   context_offset (X9),
   context_offset (X10),
   context_offset (X11),
   context_offset (X12),
   context_offset (X13),
   context_offset (X14),
   context_offset (X15),
   context_offset (X16),
   context_offset (X17),
   context_offset (X18),
   context_offset (X19),
   context_offset (X20),
   context_offset (X21),
   context_offset (X22),
   context_offset (X23),
   context_offset (X24),
   context_offset (X25),
   context_offset (X26),
   context_offset (X27),
   context_offset (X28),
   context_offset (Fp),
   context_offset (Lr),
   context_offset (Sp),
   context_offset (Pc),
   context_offset (Cpsr),
   context_offset (V[0]),
   context_offset (V[1]),
   context_offset (V[2]),
   context_offset (V[3]),
   context_offset (V[4]),
   context_offset (V[5]),
   context_offset (V[6]),
   context_offset (V[7]),
   context_offset (V[8]),
   context_offset (V[9]),
   context_offset (V[10]),
   context_offset (V[11]),
   context_offset (V[12]),
   context_offset (V[13]),
   context_offset (V[14]),
   context_offset (V[15]),
   context_offset (V[16]),
   context_offset (V[17]),
   context_offset (V[18]),
   context_offset (V[19]),
   context_offset (V[20]),
   context_offset (V[21]),
   context_offset (V[22]),
   context_offset (V[23]),
   context_offset (V[24]),
   context_offset (V[25]),
   context_offset (V[26]),
   context_offset (V[27]),
   context_offset (V[28]),
   context_offset (V[29]),
   context_offset (V[30]),
   context_offset (V[31]),
   context_offset (Fpsr),
   context_offset (Fpcr),
 };
 #undef context_offset

 /* Implement the "stopped_data_addresses" target_ops method.  */

 std::vector<CORE_ADDR>
 aarch64_windows_nat_target::stopped_data_addresses ()
 {
   if (aarch64_windows_process.siginfo_er.ExceptionCode != EXCEPTION_BREAKPOINT
       || aarch64_windows_process.siginfo_er.NumberParameters != 2)
     return {};

   const CORE_ADDR addr_trap
     = (CORE_ADDR) aarch64_windows_process.siginfo_er.ExceptionInformation[1];

   struct aarch64_debug_reg_state *state
     = aarch64_get_debug_reg_state (inferior_ptid.pid ());
   return aarch64_stopped_data_addresses (state, addr_trap);
 }

 /* Implement the "stopped_by_watchpoint" target_ops method.  */

 bool
 aarch64_windows_nat_target::stopped_by_watchpoint ()
 {
   return !stopped_data_addresses ().empty ();
 }

 /* See windows-nat.h.  */

 void
 aarch64_windows_nat_target::initialize_windows_arch (bool attaching)
 {
   memset (&aarch64_windows_process.dr_state, 0,
 	  sizeof (aarch64_windows_process.dr_state));

   aarch64_windows_process.mappings = aarch64_mappings;
 }

 /* See windows-nat.h.  */

 void
 aarch64_windows_nat_target::cleanup_windows_arch ()
 {
   aarch64_remove_debug_reg_state (inferior_ptid.pid ());
 }

 /* See windows-nat.h.  */

 void
 aarch64_windows_nat_target::fill_thread_context (windows_thread_info *th)
 {
   CONTEXT *context = &th->context;

   context->ContextFlags = WindowsContext<decltype(context)>::all;
   CHECK (get_thread_context (th->h, context));
 }

 /* See windows-nat.h.  */

 void
 aarch64_windows_nat_target::thread_context_continue (windows_thread_info *th,
 						     int killed)
 {
   CONTEXT *context = &th->context;

   if (th->debug_registers_changed)
     {
       context->ContextFlags |= WindowsContext<decltype(context)>::debug;
       for (int i = 0; i < aarch64_num_bp_regs; i++)
 	{
 	  context->Bvr[i] = aarch64_windows_process.dr_state.dr_addr_bp[i];
 	  context->Bcr[i] = aarch64_windows_process.dr_state.dr_ctrl_bp[i];
 	}
       for (int i = 0; i < aarch64_num_wp_regs; i++)
 	{
 	  context->Wvr[i] = aarch64_windows_process.dr_state.dr_addr_wp[i];
 	  context->Wcr[i] = aarch64_windows_process.dr_state.dr_ctrl_wp[i];
 	}
       th->debug_registers_changed = false;
     }

   if (context->ContextFlags)
     {
       DWORD ec = 0;

       if (GetExitCodeThread (th->h, &ec)
 	  && ec == STILL_ACTIVE)
 	{
 	  BOOL status = set_thread_context (th->h, context);

 	  if (!killed)
 	    CHECK (status);
 	}
       context->ContextFlags = 0;
     }
 }

 /* See windows-nat.h.  */

 void
 aarch64_windows_nat_target::thread_context_step (windows_thread_info *th)
 {
   th->context.Cpsr |= 0x200000;
 }

 /* See windows-nat.h.  */

 void
 aarch64_windows_nat_target::fetch_one_register (struct regcache *regcache,
 						windows_thread_info *th, int r)
 {
   gdb_assert (r >= 0);
   gdb_assert (!th->reload_context);

   char *context_ptr = (char *) &th->context;
   char *context_offset = context_ptr + aarch64_windows_process.mappings[r];
   struct gdbarch *gdbarch = regcache->arch ();

   gdb_assert (!gdbarch_read_pc_p (gdbarch));
   gdb_assert (gdbarch_pc_regnum (gdbarch) >= 0);
   gdb_assert (!gdbarch_write_pc_p (gdbarch));

   if (th->stopped_at_software_breakpoint
       && !th->pc_adjusted
       && r == gdbarch_pc_regnum (gdbarch))
     {
       uint64_t value;
       memcpy (&value, context_offset, 8);
       value -= gdbarch_decr_pc_after_break (gdbarch);
       memcpy (context_offset, &value, 8);
       /* Make sure we only rewrite the PC a single time.  */
       th->pc_adjusted = true;
     }
   regcache->raw_supply (r, context_offset);
 }

 /* See windows-nat.h.  */

 void
 aarch64_windows_nat_target::store_one_register (const struct regcache *regcache,
 						windows_thread_info *th, int r)
 {
   gdb_assert (r >= 0);

   char *context_ptr = (char *) &th->context;

   regcache->raw_collect (r, context_ptr + aarch64_windows_process.mappings[r]);
 }

 /* See windows-nat.h.  */

 bool
 aarch64_windows_nat_target::is_sw_breakpoint (const EXCEPTION_RECORD *er) const
 {
   /* On aarch64, hardware breakpoints also get EXCEPTION_BREAKPOINT,
      but they can be recognized with ExceptionInformation.  */
   return (er->ExceptionCode == EXCEPTION_BREAKPOINT
 	  && er->NumberParameters == 1
 	  && er->ExceptionInformation[0] == 0);
 }

 /* Notify all threads that the debug registers changed.  */

 void
 aarch64_notify_debug_reg_change (ptid_t ptid,
 				 int is_watchpoint, unsigned int idx)
 {
   struct aarch64_debug_reg_state *state
     = aarch64_get_debug_reg_state (inferior_ptid.pid ());
   aarch64_windows_process.dr_state = *state;

   for (auto &th : aarch64_windows_process.thread_list)
     th->debug_registers_changed = true;
 }

 INIT_GDB_FILE (aarch64_windows_nat)
 {
   aarch64_initialize_hw_point ();

   /* Get ID_AA64DFR0_EL1 value (CP 4028) from registry.  */
   aarch64_num_bp_regs = 0;
   uint64_t cp4028;
   DWORD cp4028_size = sizeof(cp4028);
   if (RegGetValueA (HKEY_LOCAL_MACHINE,
 		    "HARDWARE\\DESCRIPTION\\System\\CentralProcessor\\0",
 		    "CP 4028", RRF_RT_REG_QWORD, NULL, &cp4028, &cp4028_size)
       == ERROR_SUCCESS)
     {
       /* Bits 12-15 are the number of breakpoints, minus 1.  */
       aarch64_num_bp_regs = ((cp4028 & 0xf000) >> 12) + 1;
       if (aarch64_num_bp_regs > ARM64_MAX_BREAKPOINTS)
 	aarch64_num_bp_regs = ARM64_MAX_BREAKPOINTS;
     }

   /* ARM64_MAX_WATCHPOINTS is 2, but only 1 works.  */
   aarch64_num_wp_regs = 1;

   /* The target is not a global specifically to avoid a C++ "static
      initializer fiasco" situation.  */
   add_inf_child_target (new aarch64_windows_nat_target);

   windows_process = &aarch64_windows_process;
 }
	/* Native-dependent code for Windows AArch64.

	Copyright (C) 2025-2026 Free Software Foundation, Inc.

	This file is part of GDB.

	This program is free software; you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation; either version 3 of the License, or
	(at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with this program. If not, see <http://www.gnu.org/licenses/>. */

	#include "windows-nat.h"
	#include "regcache.h"
	#include "gdbarch.h"
	#include "inferior.h"

	#include "aarch64-nat.h"

	using namespace windows_nat;

	struct aarch64_windows_per_inferior : public windows_per_inferior
	{
	aarch64_debug_reg_state dr_state;
	};

	struct aarch64_windows_nat_target final
	: public aarch64_nat_target<windows_nat_target>
	{
	std::vector<CORE_ADDR> stopped_data_addresses () override;
	bool stopped_by_watchpoint () override;

	void initialize_windows_arch (bool attaching) override;
	void cleanup_windows_arch () override;

	void fill_thread_context (windows_thread_info *th) override;

	void thread_context_continue (windows_thread_info *th, int killed) override;
	void thread_context_step (windows_thread_info *th) override;

	void fetch_one_register (struct regcache *regcache,
	windows_thread_info *th, int r) override;
	void store_one_register (const struct regcache *regcache,
	windows_thread_info *th, int r) override;

	bool is_sw_breakpoint (const EXCEPTION_RECORD *er) const override;
	};

	/* The current process. */
	static aarch64_windows_per_inferior aarch64_windows_process;

	#define context_offset(x) (offsetof (CONTEXT, x))
	const int aarch64_mappings[] =
	{
	context_offset (X0),
	context_offset (X1),
	context_offset (X2),
	context_offset (X3),
	context_offset (X4),
	context_offset (X5),
	context_offset (X6),
	context_offset (X7),
	context_offset (X8),
	context_offset (X9),
	context_offset (X10),
	context_offset (X11),
	context_offset (X12),
	context_offset (X13),
	context_offset (X14),
	context_offset (X15),
	context_offset (X16),
	context_offset (X17),
	context_offset (X18),
	context_offset (X19),
	context_offset (X20),
	context_offset (X21),
	context_offset (X22),
	context_offset (X23),
	context_offset (X24),
	context_offset (X25),
	context_offset (X26),
	context_offset (X27),
	context_offset (X28),
	context_offset (Fp),
	context_offset (Lr),
	context_offset (Sp),
	context_offset (Pc),
	context_offset (Cpsr),
	context_offset (V[0]),
	context_offset (V[1]),
	context_offset (V[2]),
	context_offset (V[3]),
	context_offset (V[4]),
	context_offset (V[5]),
	context_offset (V[6]),
	context_offset (V[7]),
	context_offset (V[8]),
	context_offset (V[9]),
	context_offset (V[10]),
	context_offset (V[11]),
	context_offset (V[12]),
	context_offset (V[13]),
	context_offset (V[14]),
	context_offset (V[15]),
	context_offset (V[16]),
	context_offset (V[17]),
	context_offset (V[18]),
	context_offset (V[19]),
	context_offset (V[20]),
	context_offset (V[21]),
	context_offset (V[22]),
	context_offset (V[23]),
	context_offset (V[24]),
	context_offset (V[25]),
	context_offset (V[26]),
	context_offset (V[27]),
	context_offset (V[28]),
	context_offset (V[29]),
	context_offset (V[30]),
	context_offset (V[31]),
	context_offset (Fpsr),
	context_offset (Fpcr),
	};
	#undef context_offset

	/* Implement the "stopped_data_addresses" target_ops method. */

	std::vector<CORE_ADDR>
	aarch64_windows_nat_target::stopped_data_addresses ()
	{
	if (aarch64_windows_process.siginfo_er.ExceptionCode != EXCEPTION_BREAKPOINT
	\|\| aarch64_windows_process.siginfo_er.NumberParameters != 2)
	return {};

	const CORE_ADDR addr_trap
	= (CORE_ADDR) aarch64_windows_process.siginfo_er.ExceptionInformation[1];

	struct aarch64_debug_reg_state *state
	= aarch64_get_debug_reg_state (inferior_ptid.pid ());
	return aarch64_stopped_data_addresses (state, addr_trap);
	}

	/* Implement the "stopped_by_watchpoint" target_ops method. */

	bool
	aarch64_windows_nat_target::stopped_by_watchpoint ()
	{
	return !stopped_data_addresses ().empty ();
	}

	/* See windows-nat.h. */

	void
	aarch64_windows_nat_target::initialize_windows_arch (bool attaching)
	{
	memset (&aarch64_windows_process.dr_state, 0,
	sizeof (aarch64_windows_process.dr_state));

	aarch64_windows_process.mappings = aarch64_mappings;
	}

	/* See windows-nat.h. */

	void
	aarch64_windows_nat_target::cleanup_windows_arch ()
	{
	aarch64_remove_debug_reg_state (inferior_ptid.pid ());
	}

	/* See windows-nat.h. */

	void
	aarch64_windows_nat_target::fill_thread_context (windows_thread_info *th)
	{
	CONTEXT *context = &th->context;

	context->ContextFlags = WindowsContext<decltype(context)>::all;
	CHECK (get_thread_context (th->h, context));
	}

	/* See windows-nat.h. */

	void
	aarch64_windows_nat_target::thread_context_continue (windows_thread_info *th,
	int killed)
	{
	CONTEXT *context = &th->context;

	if (th->debug_registers_changed)
	{
	context->ContextFlags \|= WindowsContext<decltype(context)>::debug;
	for (int i = 0; i < aarch64_num_bp_regs; i++)
	{
	context->Bvr[i] = aarch64_windows_process.dr_state.dr_addr_bp[i];
	context->Bcr[i] = aarch64_windows_process.dr_state.dr_ctrl_bp[i];
	}
	for (int i = 0; i < aarch64_num_wp_regs; i++)
	{
	context->Wvr[i] = aarch64_windows_process.dr_state.dr_addr_wp[i];
	context->Wcr[i] = aarch64_windows_process.dr_state.dr_ctrl_wp[i];
	}
	th->debug_registers_changed = false;
	}

	if (context->ContextFlags)
	{
	DWORD ec = 0;

	if (GetExitCodeThread (th->h, &ec)
	&& ec == STILL_ACTIVE)
	{
	BOOL status = set_thread_context (th->h, context);

	if (!killed)
	CHECK (status);
	}
	context->ContextFlags = 0;
	}
	}

	/* See windows-nat.h. */

	void
	aarch64_windows_nat_target::thread_context_step (windows_thread_info *th)
	{
	th->context.Cpsr \|= 0x200000;
	}

	/* See windows-nat.h. */

	void
	aarch64_windows_nat_target::fetch_one_register (struct regcache *regcache,
	windows_thread_info *th, int r)
	{
	gdb_assert (r >= 0);
	gdb_assert (!th->reload_context);

	char context_ptr = (char ) &th->context;
	char *context_offset = context_ptr + aarch64_windows_process.mappings[r];
	struct gdbarch *gdbarch = regcache->arch ();

	gdb_assert (!gdbarch_read_pc_p (gdbarch));
	gdb_assert (gdbarch_pc_regnum (gdbarch) >= 0);
	gdb_assert (!gdbarch_write_pc_p (gdbarch));

	if (th->stopped_at_software_breakpoint
	&& !th->pc_adjusted
	&& r == gdbarch_pc_regnum (gdbarch))
	{
	uint64_t value;
	memcpy (&value, context_offset, 8);
	value -= gdbarch_decr_pc_after_break (gdbarch);
	memcpy (context_offset, &value, 8);
	/* Make sure we only rewrite the PC a single time. */
	th->pc_adjusted = true;
	}
	regcache->raw_supply (r, context_offset);
	}

	/* See windows-nat.h. */

	void
	aarch64_windows_nat_target::store_one_register (const struct regcache *regcache,
	windows_thread_info *th, int r)
	{
	gdb_assert (r >= 0);

	char context_ptr = (char ) &th->context;

	regcache->raw_collect (r, context_ptr + aarch64_windows_process.mappings[r]);
	}

	/* See windows-nat.h. */

	bool
	aarch64_windows_nat_target::is_sw_breakpoint (const EXCEPTION_RECORD *er) const
	{
	/* On aarch64, hardware breakpoints also get EXCEPTION_BREAKPOINT,
	but they can be recognized with ExceptionInformation. */
	return (er->ExceptionCode == EXCEPTION_BREAKPOINT
	&& er->NumberParameters == 1
	&& er->ExceptionInformation[0] == 0);
	}

	/* Notify all threads that the debug registers changed. */

	void
	aarch64_notify_debug_reg_change (ptid_t ptid,
	int is_watchpoint, unsigned int idx)
	{
	struct aarch64_debug_reg_state *state
	= aarch64_get_debug_reg_state (inferior_ptid.pid ());
	aarch64_windows_process.dr_state = *state;

	for (auto &th : aarch64_windows_process.thread_list)
	th->debug_registers_changed = true;
	}

	INIT_GDB_FILE (aarch64_windows_nat)
	{
	aarch64_initialize_hw_point ();

	/* Get ID_AA64DFR0_EL1 value (CP 4028) from registry. */
	aarch64_num_bp_regs = 0;
	uint64_t cp4028;
	DWORD cp4028_size = sizeof(cp4028);
	if (RegGetValueA (HKEY_LOCAL_MACHINE,
	"HARDWARE\\DESCRIPTION\\System\\CentralProcessor\\0",
	"CP 4028", RRF_RT_REG_QWORD, NULL, &cp4028, &cp4028_size)
	== ERROR_SUCCESS)
	{
	/* Bits 12-15 are the number of breakpoints, minus 1. */
	aarch64_num_bp_regs = ((cp4028 & 0xf000) >> 12) + 1;
	if (aarch64_num_bp_regs > ARM64_MAX_BREAKPOINTS)
	aarch64_num_bp_regs = ARM64_MAX_BREAKPOINTS;
	}

	/* ARM64_MAX_WATCHPOINTS is 2, but only 1 works. */
	aarch64_num_wp_regs = 1;

	/* The target is not a global specifically to avoid a C++ "static
	initializer fiasco" situation. */
	add_inf_child_target (new aarch64_windows_nat_target);

	windows_process = &aarch64_windows_process;
	}