/* Native-dependent code for the i386.
- Copyright (C) 2001, 2004-2005, 2007-2012 Free Software Foundation,
- Inc.
+ Copyright (C) 2001-2014 Free Software Foundation, Inc.
This file is part of GDB.
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 "i386-nat.h"
#include "defs.h"
+#include "i386-nat.h"
#include "breakpoint.h"
#include "command.h"
#include "gdbcmd.h"
#include "target.h"
#include "gdb_assert.h"
+#include "inferior.h"
/* Support for hardware watchpoints and breakpoints using the i386
debug registers.
/* A macro to loop over all debug registers. */
#define ALL_DEBUG_REGISTERS(i) for (i = 0; i < DR_NADDR; i++)
-/* Clear the reference counts and forget everything we knew about the
- debug registers. */
+/* Per-process data. We don't bind this to a per-inferior registry
+ because of targets like x86 GNU/Linux that need to keep track of
+ processes that aren't bound to any inferior (e.g., fork children,
+ checkpoints). */
-static void
-i386_init_dregs (struct i386_debug_reg_state *state)
+struct i386_process_info
{
- int i;
+ /* Linked list. */
+ struct i386_process_info *next;
- ALL_DEBUG_REGISTERS (i)
- {
- state->dr_mirror[i] = 0;
- state->dr_ref_count[i] = 0;
- }
- state->dr_control_mirror = 0;
- state->dr_status_mirror = 0;
+ /* The process identifier. */
+ pid_t pid;
+
+ /* Copy of i386 hardware debug registers. */
+ struct i386_debug_reg_state state;
+};
+
+static struct i386_process_info *i386_process_list = NULL;
+
+/* Find process data for process PID. */
+
+static struct i386_process_info *
+i386_find_process_pid (pid_t pid)
+{
+ struct i386_process_info *proc;
+
+ for (proc = i386_process_list; proc; proc = proc->next)
+ if (proc->pid == pid)
+ return proc;
+
+ return NULL;
+}
+
+/* Add process data for process PID. Returns newly allocated info
+ object. */
+
+static struct i386_process_info *
+i386_add_process (pid_t pid)
+{
+ struct i386_process_info *proc;
+
+ proc = xcalloc (1, sizeof (*proc));
+ proc->pid = pid;
+
+ proc->next = i386_process_list;
+ i386_process_list = proc;
+
+ return proc;
}
-/* The local mirror of the inferior's debug registers. Currently this
- is a global, but it should really be per-inferior. */
-static struct i386_debug_reg_state dr_mirror;
+/* Get data specific info for process PID, creating it if necessary.
+ Never returns NULL. */
+
+static struct i386_process_info *
+i386_process_info_get (pid_t pid)
+{
+ struct i386_process_info *proc;
+
+ proc = i386_find_process_pid (pid);
+ if (proc == NULL)
+ proc = i386_add_process (pid);
+
+ return proc;
+}
+
+/* Get debug registers state for process PID. */
struct i386_debug_reg_state *
-i386_debug_reg_state (void)
+i386_debug_reg_state (pid_t pid)
{
- return &dr_mirror;
+ return &i386_process_info_get (pid)->state;
+}
+
+/* See declaration in i386-nat.h. */
+
+void
+i386_forget_process (pid_t pid)
+{
+ struct i386_process_info *proc, **proc_link;
+
+ proc = i386_process_list;
+ proc_link = &i386_process_list;
+
+ while (proc != NULL)
+ {
+ if (proc->pid == pid)
+ {
+ *proc_link = proc->next;
+
+ xfree (proc);
+ return;
+ }
+
+ proc_link = &proc->next;
+ proc = *proc_link;
+ }
}
/* Whether or not to print the mirrored debug registers. */
void
i386_cleanup_dregs (void)
{
- i386_init_dregs (&dr_mirror);
+ /* Starting from scratch has the same effect. */
+ i386_forget_process (ptid_get_pid (inferior_ptid));
}
/* Print the values of the mirrored debug registers. This is called
const char *func, CORE_ADDR addr,
int len, enum target_hw_bp_type type)
{
- int addr_size = gdbarch_addr_bit (target_gdbarch) / 8;
+ int addr_size = gdbarch_addr_bit (target_gdbarch ()) / 8;
int i;
puts_unfiltered (func);
static void
i386_update_inferior_debug_regs (struct i386_debug_reg_state *new_state)
{
+ struct i386_debug_reg_state *state
+ = i386_debug_reg_state (ptid_get_pid (inferior_ptid));
int i;
ALL_DEBUG_REGISTERS (i)
{
- if (I386_DR_VACANT (new_state, i) != I386_DR_VACANT (&dr_mirror, i))
+ if (I386_DR_VACANT (new_state, i) != I386_DR_VACANT (state, i))
i386_dr_low.set_addr (i, new_state->dr_mirror[i]);
else
- gdb_assert (new_state->dr_mirror[i] == dr_mirror.dr_mirror[i]);
+ gdb_assert (new_state->dr_mirror[i] == state->dr_mirror[i]);
}
- if (new_state->dr_control_mirror != dr_mirror.dr_control_mirror)
+ if (new_state->dr_control_mirror != state->dr_control_mirror)
i386_dr_low.set_control (new_state->dr_control_mirror);
- dr_mirror = *new_state;
+ *state = *new_state;
}
/* Insert a watchpoint to watch a memory region which starts at
i386_insert_watchpoint (CORE_ADDR addr, int len, int type,
struct expression *cond)
{
+ struct i386_debug_reg_state *state
+ = i386_debug_reg_state (ptid_get_pid (inferior_ptid));
int retval;
/* Work on a local copy of the debug registers, and on success,
commit the change back to the inferior. */
- struct i386_debug_reg_state local_state = dr_mirror;
+ struct i386_debug_reg_state local_state = *state;
if (type == hw_read)
return 1; /* unsupported */
i386_update_inferior_debug_regs (&local_state);
if (maint_show_dr)
- i386_show_dr (&dr_mirror, "insert_watchpoint", addr, len, type);
+ i386_show_dr (state, "insert_watchpoint", addr, len, type);
return retval;
}
i386_remove_watchpoint (CORE_ADDR addr, int len, int type,
struct expression *cond)
{
+ struct i386_debug_reg_state *state
+ = i386_debug_reg_state (ptid_get_pid (inferior_ptid));
int retval;
/* Work on a local copy of the debug registers, and on success,
commit the change back to the inferior. */
- struct i386_debug_reg_state local_state = dr_mirror;
+ struct i386_debug_reg_state local_state = *state;
if (((len != 1 && len !=2 && len !=4) && !(TARGET_HAS_DR_LEN_8 && len == 8))
|| addr % len != 0)
i386_update_inferior_debug_regs (&local_state);
if (maint_show_dr)
- i386_show_dr (&dr_mirror, "remove_watchpoint", addr, len, type);
+ i386_show_dr (state, "remove_watchpoint", addr, len, type);
return retval;
}
static int
i386_region_ok_for_watchpoint (CORE_ADDR addr, int len)
{
+ struct i386_debug_reg_state *state
+ = i386_debug_reg_state (ptid_get_pid (inferior_ptid));
int nregs;
/* Compute how many aligned watchpoints we would need to cover this
region. */
- nregs = i386_handle_nonaligned_watchpoint (&dr_mirror,
+ nregs = i386_handle_nonaligned_watchpoint (state,
WP_COUNT, addr, len, hw_write);
return nregs <= DR_NADDR ? 1 : 0;
}
static int
i386_stopped_data_address (struct target_ops *ops, CORE_ADDR *addr_p)
{
+ struct i386_debug_reg_state *state
+ = i386_debug_reg_state (ptid_get_pid (inferior_ptid));
CORE_ADDR addr = 0;
int i;
int rc = 0;
unsigned control = 0;
/* In non-stop/async, threads can be running while we change the
- global dr_mirror (and friends). Say, we set a watchpoint, and
- let threads resume. Now, say you delete the watchpoint, or
- add/remove watchpoints such that dr_mirror changes while threads
- are running. On targets that support non-stop,
- inserting/deleting watchpoints updates the global dr_mirror only.
- It does not update the real thread's debug registers; that's only
- done prior to resume. Instead, if threads are running when the
- mirror changes, a temporary and transparent stop on all threads
- is forced so they can get their copy of the debug registers
- updated on re-resume. Now, say, a thread hit a watchpoint before
- having been updated with the new dr_mirror contents, and we
- haven't yet handled the corresponding SIGTRAP. If we trusted
- dr_mirror below, we'd mistake the real trapped address (from the
- last time we had updated debug registers in the thread) with
- whatever was currently in dr_mirror. So to fix this, dr_mirror
- always represents intention, what we _want_ threads to have in
- debug registers. To get at the address and cause of the trap, we
- need to read the state the thread still has in its debug
- registers.
+ STATE (and friends). Say, we set a watchpoint, and let threads
+ resume. Now, say you delete the watchpoint, or add/remove
+ watchpoints such that STATE changes while threads are running.
+ On targets that support non-stop, inserting/deleting watchpoints
+ updates the STATE only. It does not update the real thread's
+ debug registers; that's only done prior to resume. Instead, if
+ threads are running when the mirror changes, a temporary and
+ transparent stop on all threads is forced so they can get their
+ copy of the debug registers updated on re-resume. Now, say,
+ a thread hit a watchpoint before having been updated with the new
+ STATE contents, and we haven't yet handled the corresponding
+ SIGTRAP. If we trusted STATE below, we'd mistake the real
+ trapped address (from the last time we had updated debug
+ registers in the thread) with whatever was currently in STATE.
+ So to fix this, STATE always represents intention, what we _want_
+ threads to have in debug registers. To get at the address and
+ cause of the trap, we need to read the state the thread still has
+ in its debug registers.
In sum, always get the current debug register values the current
thread has, instead of trusting the global mirror. If the thread
addr = i386_dr_low.get_addr (i);
rc = 1;
if (maint_show_dr)
- i386_show_dr (&dr_mirror, "watchpoint_hit", addr, -1, hw_write);
+ i386_show_dr (state, "watchpoint_hit", addr, -1, hw_write);
}
}
if (maint_show_dr && addr == 0)
- i386_show_dr (&dr_mirror, "stopped_data_addr", 0, 0, hw_write);
+ i386_show_dr (state, "stopped_data_addr", 0, 0, hw_write);
if (rc)
*addr_p = addr;
i386_insert_hw_breakpoint (struct gdbarch *gdbarch,
struct bp_target_info *bp_tgt)
{
+ struct i386_debug_reg_state *state
+ = i386_debug_reg_state (ptid_get_pid (inferior_ptid));
unsigned len_rw = i386_length_and_rw_bits (1, hw_execute);
CORE_ADDR addr = bp_tgt->placed_address;
/* Work on a local copy of the debug registers, and on success,
commit the change back to the inferior. */
- struct i386_debug_reg_state local_state = dr_mirror;
+ struct i386_debug_reg_state local_state = *state;
int retval = i386_insert_aligned_watchpoint (&local_state,
addr, len_rw) ? EBUSY : 0;
i386_update_inferior_debug_regs (&local_state);
if (maint_show_dr)
- i386_show_dr (&dr_mirror, "insert_hwbp", addr, 1, hw_execute);
+ i386_show_dr (state, "insert_hwbp", addr, 1, hw_execute);
return retval;
}
i386_remove_hw_breakpoint (struct gdbarch *gdbarch,
struct bp_target_info *bp_tgt)
{
+ struct i386_debug_reg_state *state
+ = i386_debug_reg_state (ptid_get_pid (inferior_ptid));
unsigned len_rw = i386_length_and_rw_bits (1, hw_execute);
CORE_ADDR addr = bp_tgt->placed_address;
/* Work on a local copy of the debug registers, and on success,
commit the change back to the inferior. */
- struct i386_debug_reg_state local_state = dr_mirror;
+ struct i386_debug_reg_state local_state = *state;
int retval = i386_remove_aligned_watchpoint (&local_state,
addr, len_rw);
i386_update_inferior_debug_regs (&local_state);
if (maint_show_dr)
- i386_show_dr (&dr_mirror, "remove_hwbp", addr, 1, hw_execute);
+ i386_show_dr (state, "remove_hwbp", addr, 1, hw_execute);
return retval;
}
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