binutils-gdb/gdbserver/win32-i386-low.cc
Hannes Domani 013707794a Enable hardware breakpoints for gdbserver on Windows
When trying to use hardware breakpoints with gdbserver you get this error:

(gdb) hbreak main
Hardware assisted breakpoint 2 at 0x40162d: file gdb-9493.c, line 5.
(gdb) c
Continuing.
Warning:
Cannot insert hardware breakpoint 2.
Could not insert hardware breakpoints:
You may have requested too many hardware breakpoints/watchpoints.

It turns out the respective types just needed to be added to the
appropriate callback functions, because x86_dr_(insert|remove)_watchpoint
already handles them.

gdbserver/ChangeLog:

2020-05-15  Hannes Domani  <ssbssa@yahoo.de>

	* win32-i386-low.cc (i386_supports_z_point_type): Handle
	Z_PACKET_HW_BP z_type.
	(i386_insert_point): Handle raw_bkpt_type type.
	(i386_remove_point): Likewise.
2020-05-15 10:55:21 +02:00

626 lines
15 KiB
C++

/* Copyright (C) 2007-2020 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 "server.h"
#include "win32-low.h"
#include "x86-low.h"
#include "gdbsupport/x86-xstate.h"
#ifdef __x86_64__
#include "arch/amd64.h"
#endif
#include "arch/i386.h"
#include "tdesc.h"
#include "x86-tdesc.h"
using namespace windows_nat;
#ifndef CONTEXT_EXTENDED_REGISTERS
#define CONTEXT_EXTENDED_REGISTERS 0
#endif
#define FCS_REGNUM 27
#define FOP_REGNUM 31
#define FLAG_TRACE_BIT 0x100
static struct x86_debug_reg_state debug_reg_state;
static void
update_debug_registers (thread_info *thread)
{
windows_thread_info *th = (windows_thread_info *) thread_target_data (thread);
/* The actual update is done later just before resuming the lwp,
we just mark that the registers need updating. */
th->debug_registers_changed = true;
}
/* Update the inferior's debug register REGNUM from STATE. */
static void
x86_dr_low_set_addr (int regnum, CORE_ADDR addr)
{
gdb_assert (DR_FIRSTADDR <= regnum && regnum <= DR_LASTADDR);
/* Only update the threads of this process. */
for_each_thread (current_thread->id.pid (), update_debug_registers);
}
/* Update the inferior's DR7 debug control register from STATE. */
static void
x86_dr_low_set_control (unsigned long control)
{
/* Only update the threads of this process. */
for_each_thread (current_thread->id.pid (), update_debug_registers);
}
/* Return the current value of a DR register of the current thread's
context. */
static DWORD64
win32_get_current_dr (int dr)
{
windows_thread_info *th
= (windows_thread_info *) thread_target_data (current_thread);
win32_require_context (th);
#ifdef __x86_64__
#define RET_DR(DR) \
case DR: \
return th->wow64_context.Dr ## DR
if (wow64_process)
{
switch (dr)
{
RET_DR (0);
RET_DR (1);
RET_DR (2);
RET_DR (3);
RET_DR (6);
RET_DR (7);
}
}
else
#undef RET_DR
#endif
#define RET_DR(DR) \
case DR: \
return th->context.Dr ## DR
{
switch (dr)
{
RET_DR (0);
RET_DR (1);
RET_DR (2);
RET_DR (3);
RET_DR (6);
RET_DR (7);
}
}
#undef RET_DR
gdb_assert_not_reached ("unhandled dr");
}
static CORE_ADDR
x86_dr_low_get_addr (int regnum)
{
gdb_assert (DR_FIRSTADDR <= regnum && regnum <= DR_LASTADDR);
return win32_get_current_dr (regnum - DR_FIRSTADDR);
}
static unsigned long
x86_dr_low_get_control (void)
{
return win32_get_current_dr (7);
}
/* Get the value of the DR6 debug status register from the inferior
and record it in STATE. */
static unsigned long
x86_dr_low_get_status (void)
{
return win32_get_current_dr (6);
}
/* Low-level function vector. */
struct x86_dr_low_type x86_dr_low =
{
x86_dr_low_set_control,
x86_dr_low_set_addr,
x86_dr_low_get_addr,
x86_dr_low_get_status,
x86_dr_low_get_control,
sizeof (void *),
};
/* Breakpoint/watchpoint support. */
static int
i386_supports_z_point_type (char z_type)
{
switch (z_type)
{
case Z_PACKET_HW_BP:
case Z_PACKET_WRITE_WP:
case Z_PACKET_ACCESS_WP:
return 1;
default:
return 0;
}
}
static int
i386_insert_point (enum raw_bkpt_type type, CORE_ADDR addr,
int size, struct raw_breakpoint *bp)
{
switch (type)
{
case raw_bkpt_type_hw:
case raw_bkpt_type_write_wp:
case raw_bkpt_type_access_wp:
{
enum target_hw_bp_type hw_type
= raw_bkpt_type_to_target_hw_bp_type (type);
return x86_dr_insert_watchpoint (&debug_reg_state,
hw_type, addr, size);
}
default:
/* Unsupported. */
return 1;
}
}
static int
i386_remove_point (enum raw_bkpt_type type, CORE_ADDR addr,
int size, struct raw_breakpoint *bp)
{
switch (type)
{
case raw_bkpt_type_hw:
case raw_bkpt_type_write_wp:
case raw_bkpt_type_access_wp:
{
enum target_hw_bp_type hw_type
= raw_bkpt_type_to_target_hw_bp_type (type);
return x86_dr_remove_watchpoint (&debug_reg_state,
hw_type, addr, size);
}
default:
/* Unsupported. */
return 1;
}
}
static int
x86_stopped_by_watchpoint (void)
{
return x86_dr_stopped_by_watchpoint (&debug_reg_state);
}
static CORE_ADDR
x86_stopped_data_address (void)
{
CORE_ADDR addr;
if (x86_dr_stopped_data_address (&debug_reg_state, &addr))
return addr;
return 0;
}
static void
i386_initial_stuff (void)
{
x86_low_init_dregs (&debug_reg_state);
}
static void
i386_get_thread_context (windows_thread_info *th)
{
/* Requesting the CONTEXT_EXTENDED_REGISTERS register set fails if
the system doesn't support extended registers. */
static DWORD extended_registers = CONTEXT_EXTENDED_REGISTERS;
again:
#ifdef __x86_64__
if (wow64_process)
th->wow64_context.ContextFlags = (CONTEXT_FULL
| CONTEXT_FLOATING_POINT
| CONTEXT_DEBUG_REGISTERS
| extended_registers);
else
#endif
th->context.ContextFlags = (CONTEXT_FULL
| CONTEXT_FLOATING_POINT
| CONTEXT_DEBUG_REGISTERS
| extended_registers);
BOOL ret;
#ifdef __x86_64__
if (wow64_process)
ret = win32_Wow64GetThreadContext (th->h, &th->wow64_context);
else
#endif
ret = GetThreadContext (th->h, &th->context);
if (!ret)
{
DWORD e = GetLastError ();
if (extended_registers && e == ERROR_INVALID_PARAMETER)
{
extended_registers = 0;
goto again;
}
error ("GetThreadContext failure %ld\n", (long) e);
}
}
static void
i386_prepare_to_resume (windows_thread_info *th)
{
if (th->debug_registers_changed)
{
struct x86_debug_reg_state *dr = &debug_reg_state;
win32_require_context (th);
#ifdef __x86_64__
if (wow64_process)
{
th->wow64_context.Dr0 = dr->dr_mirror[0];
th->wow64_context.Dr1 = dr->dr_mirror[1];
th->wow64_context.Dr2 = dr->dr_mirror[2];
th->wow64_context.Dr3 = dr->dr_mirror[3];
/* th->wow64_context.Dr6 = dr->dr_status_mirror;
FIXME: should we set dr6 also ?? */
th->wow64_context.Dr7 = dr->dr_control_mirror;
}
else
#endif
{
th->context.Dr0 = dr->dr_mirror[0];
th->context.Dr1 = dr->dr_mirror[1];
th->context.Dr2 = dr->dr_mirror[2];
th->context.Dr3 = dr->dr_mirror[3];
/* th->context.Dr6 = dr->dr_status_mirror;
FIXME: should we set dr6 also ?? */
th->context.Dr7 = dr->dr_control_mirror;
}
th->debug_registers_changed = false;
}
}
static void
i386_thread_added (windows_thread_info *th)
{
th->debug_registers_changed = true;
}
static void
i386_single_step (windows_thread_info *th)
{
#ifdef __x86_64__
if (wow64_process)
th->wow64_context.EFlags |= FLAG_TRACE_BIT;
else
#endif
th->context.EFlags |= FLAG_TRACE_BIT;
}
/* An array of offset mappings into a Win32 Context structure.
This is a one-to-one mapping which is indexed by gdb's register
numbers. It retrieves an offset into the context structure where
the 4 byte register is located.
An offset value of -1 indicates that Win32 does not provide this
register in it's CONTEXT structure. In this case regptr will return
a pointer into a dummy register. */
#ifdef __x86_64__
#define context_offset(x) (offsetof (WOW64_CONTEXT, x))
#else
#define context_offset(x) ((int)&(((CONTEXT *)NULL)->x))
#endif
static const int i386_mappings[] = {
context_offset (Eax),
context_offset (Ecx),
context_offset (Edx),
context_offset (Ebx),
context_offset (Esp),
context_offset (Ebp),
context_offset (Esi),
context_offset (Edi),
context_offset (Eip),
context_offset (EFlags),
context_offset (SegCs),
context_offset (SegSs),
context_offset (SegDs),
context_offset (SegEs),
context_offset (SegFs),
context_offset (SegGs),
context_offset (FloatSave.RegisterArea[0 * 10]),
context_offset (FloatSave.RegisterArea[1 * 10]),
context_offset (FloatSave.RegisterArea[2 * 10]),
context_offset (FloatSave.RegisterArea[3 * 10]),
context_offset (FloatSave.RegisterArea[4 * 10]),
context_offset (FloatSave.RegisterArea[5 * 10]),
context_offset (FloatSave.RegisterArea[6 * 10]),
context_offset (FloatSave.RegisterArea[7 * 10]),
context_offset (FloatSave.ControlWord),
context_offset (FloatSave.StatusWord),
context_offset (FloatSave.TagWord),
context_offset (FloatSave.ErrorSelector),
context_offset (FloatSave.ErrorOffset),
context_offset (FloatSave.DataSelector),
context_offset (FloatSave.DataOffset),
context_offset (FloatSave.ErrorSelector),
/* XMM0-7 */
context_offset (ExtendedRegisters[10 * 16]),
context_offset (ExtendedRegisters[11 * 16]),
context_offset (ExtendedRegisters[12 * 16]),
context_offset (ExtendedRegisters[13 * 16]),
context_offset (ExtendedRegisters[14 * 16]),
context_offset (ExtendedRegisters[15 * 16]),
context_offset (ExtendedRegisters[16 * 16]),
context_offset (ExtendedRegisters[17 * 16]),
/* MXCSR */
context_offset (ExtendedRegisters[24])
};
#undef context_offset
#ifdef __x86_64__
#define context_offset(x) (offsetof (CONTEXT, x))
static const int amd64_mappings[] =
{
context_offset (Rax),
context_offset (Rbx),
context_offset (Rcx),
context_offset (Rdx),
context_offset (Rsi),
context_offset (Rdi),
context_offset (Rbp),
context_offset (Rsp),
context_offset (R8),
context_offset (R9),
context_offset (R10),
context_offset (R11),
context_offset (R12),
context_offset (R13),
context_offset (R14),
context_offset (R15),
context_offset (Rip),
context_offset (EFlags),
context_offset (SegCs),
context_offset (SegSs),
context_offset (SegDs),
context_offset (SegEs),
context_offset (SegFs),
context_offset (SegGs),
context_offset (FloatSave.FloatRegisters[0]),
context_offset (FloatSave.FloatRegisters[1]),
context_offset (FloatSave.FloatRegisters[2]),
context_offset (FloatSave.FloatRegisters[3]),
context_offset (FloatSave.FloatRegisters[4]),
context_offset (FloatSave.FloatRegisters[5]),
context_offset (FloatSave.FloatRegisters[6]),
context_offset (FloatSave.FloatRegisters[7]),
context_offset (FloatSave.ControlWord),
context_offset (FloatSave.StatusWord),
context_offset (FloatSave.TagWord),
context_offset (FloatSave.ErrorSelector),
context_offset (FloatSave.ErrorOffset),
context_offset (FloatSave.DataSelector),
context_offset (FloatSave.DataOffset),
context_offset (FloatSave.ErrorSelector)
/* XMM0-7 */ ,
context_offset (Xmm0),
context_offset (Xmm1),
context_offset (Xmm2),
context_offset (Xmm3),
context_offset (Xmm4),
context_offset (Xmm5),
context_offset (Xmm6),
context_offset (Xmm7),
context_offset (Xmm8),
context_offset (Xmm9),
context_offset (Xmm10),
context_offset (Xmm11),
context_offset (Xmm12),
context_offset (Xmm13),
context_offset (Xmm14),
context_offset (Xmm15),
/* MXCSR */
context_offset (FloatSave.MxCsr)
};
#undef context_offset
#endif /* __x86_64__ */
/* Fetch register from gdbserver regcache data. */
static void
i386_fetch_inferior_register (struct regcache *regcache,
windows_thread_info *th, int r)
{
const int *mappings;
#ifdef __x86_64__
if (!wow64_process)
mappings = amd64_mappings;
else
#endif
mappings = i386_mappings;
char *context_offset;
#ifdef __x86_64__
if (wow64_process)
context_offset = (char *) &th->wow64_context + mappings[r];
else
#endif
context_offset = (char *) &th->context + mappings[r];
long l;
if (r == FCS_REGNUM)
{
l = *((long *) context_offset) & 0xffff;
supply_register (regcache, r, (char *) &l);
}
else if (r == FOP_REGNUM)
{
l = (*((long *) context_offset) >> 16) & ((1 << 11) - 1);
supply_register (regcache, r, (char *) &l);
}
else
supply_register (regcache, r, context_offset);
}
/* Store a new register value into the thread context of TH. */
static void
i386_store_inferior_register (struct regcache *regcache,
windows_thread_info *th, int r)
{
const int *mappings;
#ifdef __x86_64__
if (!wow64_process)
mappings = amd64_mappings;
else
#endif
mappings = i386_mappings;
char *context_offset;
#ifdef __x86_64__
if (wow64_process)
context_offset = (char *) &th->wow64_context + mappings[r];
else
#endif
context_offset = (char *) &th->context + mappings[r];
collect_register (regcache, r, context_offset);
}
static const unsigned char i386_win32_breakpoint = 0xcc;
#define i386_win32_breakpoint_len 1
static void
i386_arch_setup (void)
{
struct target_desc *tdesc;
#ifdef __x86_64__
tdesc = amd64_create_target_description (X86_XSTATE_SSE_MASK, false,
false, false);
init_target_desc (tdesc, amd64_expedite_regs);
win32_tdesc = tdesc;
#endif
tdesc = i386_create_target_description (X86_XSTATE_SSE_MASK, false, false);
init_target_desc (tdesc, i386_expedite_regs);
#ifdef __x86_64__
wow64_win32_tdesc = tdesc;
#else
win32_tdesc = tdesc;
#endif
}
/* Implement win32_target_ops "num_regs" method. */
static int
i386_win32_num_regs (void)
{
int num_regs;
#ifdef __x86_64__
if (!wow64_process)
num_regs = sizeof (amd64_mappings) / sizeof (amd64_mappings[0]);
else
#endif
num_regs = sizeof (i386_mappings) / sizeof (i386_mappings[0]);
return num_regs;
}
/* Implement win32_target_ops "get_pc" method. */
static CORE_ADDR
i386_win32_get_pc (struct regcache *regcache)
{
bool use_64bit = register_size (regcache->tdesc, 0) == 8;
if (use_64bit)
{
uint64_t pc;
collect_register_by_name (regcache, "rip", &pc);
return (CORE_ADDR) pc;
}
else
{
uint32_t pc;
collect_register_by_name (regcache, "eip", &pc);
return (CORE_ADDR) pc;
}
}
/* Implement win32_target_ops "set_pc" method. */
static void
i386_win32_set_pc (struct regcache *regcache, CORE_ADDR pc)
{
bool use_64bit = register_size (regcache->tdesc, 0) == 8;
if (use_64bit)
{
uint64_t newpc = pc;
supply_register_by_name (regcache, "rip", &newpc);
}
else
{
uint32_t newpc = pc;
supply_register_by_name (regcache, "eip", &newpc);
}
}
struct win32_target_ops the_low_target = {
i386_arch_setup,
i386_win32_num_regs,
i386_initial_stuff,
i386_get_thread_context,
i386_prepare_to_resume,
i386_thread_added,
i386_fetch_inferior_register,
i386_store_inferior_register,
i386_single_step,
&i386_win32_breakpoint,
i386_win32_breakpoint_len,
1,
i386_win32_get_pc,
i386_win32_set_pc,
i386_supports_z_point_type,
i386_insert_point,
i386_remove_point,
x86_stopped_by_watchpoint,
x86_stopped_data_address
};