/* Native-dependent code for the i386.
- Copyright (C) 2001, 2004, 2005 Free Software Foundation, Inc.
+ Copyright (C) 2001, 2004, 2005, 2007, 2008, 2009
+ 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 2 of the License, or
+ 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,
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, write to the Free Software
- Foundation, Inc., 51 Franklin Street, Fifth Floor,
- Boston, MA 02110-1301, USA. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+#include "i386-nat.h"
#include "defs.h"
#include "breakpoint.h"
#include "command.h"
#include "gdbcmd.h"
+#include "target.h"
+#include "gdb_assert.h"
/* Support for hardware watchpoints and breakpoints using the i386
debug registers.
more of the watchpoints triggered and at what address, checking
whether a given region can be watched, etc.
- A target which wants to use these functions should define several
- macros, such as `target_insert_watchpoint' and
- `target_stopped_data_address', listed in target.h, to call the
- appropriate functions below. It should also define
- I386_USE_GENERIC_WATCHPOINTS in its tm.h file.
-
- In addition, each target should provide several low-level macros
- that will be called to insert watchpoints and hardware breakpoints
- into the inferior, remove them, and check their status. These
- macros are:
-
- I386_DR_LOW_SET_CONTROL -- set the debug control (DR7)
- register to a given value
-
- I386_DR_LOW_SET_ADDR -- put an address into one debug
- register
-
- I386_DR_LOW_RESET_ADDR -- reset the address stored in
- one debug register
-
- I386_DR_LOW_GET_STATUS -- return the value of the debug
- status (DR6) register.
-
The functions below implement debug registers sharing by reference
counts, and allow to watch regions up to 16 bytes long. */
-#ifdef I386_USE_GENERIC_WATCHPOINTS
+struct i386_dr_low_type i386_dr_low;
+
/* Support for 8-byte wide hw watchpoints. */
-#ifndef TARGET_HAS_DR_LEN_8
-#define TARGET_HAS_DR_LEN_8 0
-#endif
+#define TARGET_HAS_DR_LEN_8 (i386_dr_low.debug_register_length == 8)
/* Debug registers' indices. */
#define DR_NADDR 4 /* The number of debug address registers. */
/* Mirror the inferior's DRi registers. We keep the status and
control registers separated because they don't hold addresses. */
static CORE_ADDR dr_mirror[DR_NADDR];
-static unsigned dr_status_mirror, dr_control_mirror;
+static unsigned long dr_status_mirror, dr_control_mirror;
/* Reference counts for each debug register. */
static int dr_ref_count[DR_NADDR];
dr_status_mirror = 0;
}
-/* Reset all debug registers at each new startup to avoid missing
- watchpoints after restart. */
-
-void
-child_post_startup_inferior (ptid_t ptid)
-{
- i386_cleanup_dregs ();
-}
-
/* Print the values of the mirrored debug registers. This is called
when maint_show_dr is non-zero. To set that up, type "maint
show-debug-regs" at GDB's prompt. */
here. */
: "??unknown??"))));
puts_unfiltered (":\n");
- printf_unfiltered ("\tCONTROL (DR7): %08x STATUS (DR6): %08x\n",
- dr_control_mirror, dr_status_mirror);
+ printf_unfiltered ("\tCONTROL (DR7): %s STATUS (DR6): %s\n",
+ phex (dr_control_mirror, 8), phex (dr_status_mirror, 8));
ALL_DEBUG_REGISTERS(i)
{
printf_unfiltered ("\
{
int i;
+ if (!i386_dr_low.set_addr || !i386_dr_low.set_control)
+ return -1;
+
/* First, look for an occupied debug register with the same address
and the same RW and LEN definitions. If we find one, we can
reuse it for this watchpoint as well (and save a register). */
dr_control_mirror &= I386_DR_CONTROL_MASK;
/* Finally, actually pass the info to the inferior. */
- I386_DR_LOW_SET_ADDR (i, addr);
- I386_DR_LOW_SET_CONTROL (dr_control_mirror);
+ i386_dr_low.set_addr (i, addr);
+ i386_dr_low.set_control (dr_control_mirror);
return 0;
}
dr_mirror[i] = 0;
I386_DR_DISABLE (i);
/* Reset it in the inferior. */
- I386_DR_LOW_SET_CONTROL (dr_control_mirror);
- I386_DR_LOW_RESET_ADDR (i);
+ i386_dr_low.set_control (dr_control_mirror);
+ if (i386_dr_low.reset_addr)
+ i386_dr_low.reset_addr (i);
}
retval = 0;
}
address ADDR and whose length is LEN bytes. Watch memory accesses
of the type TYPE. Return 0 on success, -1 on failure. */
-int
+static int
i386_insert_watchpoint (CORE_ADDR addr, int len, int type)
{
int retval;
/* Remove a watchpoint that watched the memory region which starts at
address ADDR, whose length is LEN bytes, and for accesses of the
type TYPE. Return 0 on success, -1 on failure. */
-int
+static int
i386_remove_watchpoint (CORE_ADDR addr, int len, int type)
{
int retval;
/* Return non-zero if we can watch a memory region that starts at
address ADDR and whose length is LEN bytes. */
-int
+static int
i386_region_ok_for_watchpoint (CORE_ADDR addr, int len)
{
int nregs;
address associated with that watchpoint and return non-zero.
Otherwise, return zero. */
-int
-i386_stopped_data_address (CORE_ADDR *addr_p)
+static int
+i386_stopped_data_address (struct target_ops *ops, CORE_ADDR *addr_p)
{
CORE_ADDR addr = 0;
int i;
int rc = 0;
- dr_status_mirror = I386_DR_LOW_GET_STATUS ();
+ dr_status_mirror = i386_dr_low.get_status ();
ALL_DEBUG_REGISTERS(i)
{
return rc;
}
-int
+static int
i386_stopped_by_watchpoint (void)
{
CORE_ADDR addr = 0;
- return i386_stopped_data_address (&addr);
+ return i386_stopped_data_address (¤t_target, &addr);
}
/* Return non-zero if the inferior has some break/watchpoint that
triggered. */
-int
+static int
i386_stopped_by_hwbp (void)
{
int i;
- dr_status_mirror = I386_DR_LOW_GET_STATUS ();
+ dr_status_mirror = i386_dr_low.get_status ();
if (maint_show_dr)
i386_show_dr ("stopped_by_hwbp", 0, 0, hw_execute);
/* Insert a hardware-assisted breakpoint at BP_TGT->placed_address.
Return 0 on success, EBUSY on failure. */
-int
+static int
i386_insert_hw_breakpoint (struct bp_target_info *bp_tgt)
{
unsigned len_rw = i386_length_and_rw_bits (1, hw_execute);
/* Remove a hardware-assisted breakpoint at BP_TGT->placed_address.
Return 0 on success, -1 on failure. */
-int
+static int
i386_remove_hw_breakpoint (struct bp_target_info *bp_tgt)
{
unsigned len_rw = i386_length_and_rw_bits (1, hw_execute);
return retval;
}
-#endif /* I386_USE_GENERIC_WATCHPOINTS */
-\f
+/* Returns the number of hardware watchpoints of type TYPE that we can
+ set. Value is positive if we can set CNT watchpoints, zero if
+ setting watchpoints of type TYPE is not supported, and negative if
+ CNT is more than the maximum number of watchpoints of type TYPE
+ that we can support. TYPE is one of bp_hardware_watchpoint,
+ bp_read_watchpoint, bp_write_watchpoint, or bp_hardware_breakpoint.
+ CNT is the number of such watchpoints used so far (including this
+ one). OTHERTYPE is non-zero if other types of watchpoints are
+ currently enabled.
+
+ We always return 1 here because we don't have enough information
+ about possible overlap of addresses that they want to watch. As an
+ extreme example, consider the case where all the watchpoints watch
+ the same address and the same region length: then we can handle a
+ virtually unlimited number of watchpoints, due to debug register
+ sharing implemented via reference counts in i386-nat.c. */
-/* Provide a prototype to silence -Wmissing-prototypes. */
-void _initialize_i386_nat (void);
+static int
+i386_can_use_hw_breakpoint (int type, int cnt, int othertype)
+{
+ return 1;
+}
-void
-_initialize_i386_nat (void)
+static void
+add_show_debug_regs_command (void)
{
-#ifdef I386_USE_GENERIC_WATCHPOINTS
/* A maintenance command to enable printing the internal DRi mirror
variables. */
- deprecated_add_set_cmd ("show-debug-regs", class_maintenance,
- var_boolean, (char *) &maint_show_dr, _("\
-Set whether to show variables that mirror the x86 debug registers.\n\
+ add_setshow_boolean_cmd ("show-debug-regs", class_maintenance,
+ &maint_show_dr, _("\
+Set whether to show variables that mirror the x86 debug registers."), _("\
+Show whether to show variables that mirror the x86 debug registers."), _("\
Use \"on\" to enable, \"off\" to disable.\n\
If enabled, the debug registers values are shown when GDB inserts\n\
or removes a hardware breakpoint or watchpoint, and when the inferior\n\
triggers a breakpoint or watchpoint."),
- &maintenancelist);
-#endif
+ NULL,
+ NULL,
+ &maintenance_set_cmdlist,
+ &maintenance_show_cmdlist);
+}
+
+/* There are only two global functions left. */
+
+void
+i386_use_watchpoints (struct target_ops *t)
+{
+ /* After a watchpoint trap, the PC points to the instruction after the
+ one that caused the trap. Therefore we don't need to step over it.
+ But we do need to reset the status register to avoid another trap. */
+ t->to_have_continuable_watchpoint = 1;
+
+ t->to_can_use_hw_breakpoint = i386_can_use_hw_breakpoint;
+ t->to_region_ok_for_hw_watchpoint = i386_region_ok_for_watchpoint;
+ t->to_stopped_by_watchpoint = i386_stopped_by_watchpoint;
+ t->to_stopped_data_address = i386_stopped_data_address;
+ t->to_insert_watchpoint = i386_insert_watchpoint;
+ t->to_remove_watchpoint = i386_remove_watchpoint;
+ t->to_insert_hw_breakpoint = i386_insert_hw_breakpoint;
+ t->to_remove_hw_breakpoint = i386_remove_hw_breakpoint;
+}
+
+void
+i386_set_debug_register_length (int len)
+{
+ /* This function should be called only once for each native target. */
+ gdb_assert (i386_dr_low.debug_register_length == 0);
+ gdb_assert (len == 4 || len == 8);
+ i386_dr_low.debug_register_length = len;
+ add_show_debug_regs_command ();
}
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