@@ -693,6 +693,11 @@ struct arm_linux_hwbp_cap
gdb_byte bp_count;
};
+/* Since we cannot dynamically allocate subfields of arm_linux_process_info,
+ assume a maximum number of supported break-/watchpoints. */
+#define MAX_BPTS 16
+#define MAX_WPTS 16
+
/* Get hold of the Hardware Breakpoint information for the target we are
attached to. Returns NULL if the kernel doesn't support Hardware
breakpoints at all, or a pointer to the information structure. */
@@ -721,6 +726,20 @@ arm_linux_get_hwbp_cap (void)
info.max_wp_length = (gdb_byte)((val >> 16) & 0xff);
info.wp_count = (gdb_byte)((val >> 8) & 0xff);
info.bp_count = (gdb_byte)(val & 0xff);
+
+ if (info.wp_count > MAX_WPTS)
+ {
+ warning (_("arm-linux-gdb supports %d hardware watchpoints but target \
+ supports %d"), MAX_WPTS, info.wp_count);
+ info.wp_count = MAX_WPTS;
+ }
+
+ if (info.bp_count > MAX_BPTS)
+ {
+ warning (_("arm-linux-gdb supports %d hardware breakpoints but target \
+ supports %d"), MAX_BPTS, info.bp_count);
+ info.bp_count = MAX_BPTS;
+ }
available = (info.arch != 0);
}
}
@@ -788,8 +807,8 @@ struct arm_linux_hw_breakpoint
arm_hwbp_control_t control;
};
-/* Structure containing arrays of the break and watch points which are have
- active in each thread.
+/* Structure containing arrays of per process hardware break-/watchpoints
+ for caching address and control information.
The Linux ptrace interface to hardware break-/watch-points presents the
values in a vector centred around 0 (which is used fo generic information).
@@ -809,49 +828,114 @@ struct arm_linux_hw_breakpoint
We treat break-/watch-points with their enable bit clear as being deleted.
*/
-typedef struct arm_linux_thread_points
+struct arm_linux_debug_reg_state
{
- /* Thread ID. */
- int tid;
- /* Breakpoints for thread. */
- struct arm_linux_hw_breakpoint *bpts;
- /* Watchpoint for threads. */
- struct arm_linux_hw_breakpoint *wpts;
-} *arm_linux_thread_points_p;
-DEF_VEC_P (arm_linux_thread_points_p);
-
-/* Vector of hardware breakpoints for each thread. */
-VEC(arm_linux_thread_points_p) *arm_threads = NULL;
-
-/* Find the list of hardware break-/watch-points for a thread with id TID.
- If no list exists for TID we return NULL if ALLOC_NEW is 0, otherwise we
- create a new list and return that. */
-static struct arm_linux_thread_points *
-arm_linux_find_breakpoints_by_tid (int tid, int alloc_new)
+ /* Hardware breakpoints for this process. */
+ struct arm_linux_hw_breakpoint bpts[MAX_BPTS];
+ /* Hardware watchpoints for this process. */
+ struct arm_linux_hw_breakpoint wpts[MAX_WPTS];
+};
+
+/* Per-process arch-specific data we want to keep. */
+struct arm_linux_process_info
{
- int i;
- struct arm_linux_thread_points *t;
+ /* Linked list. */
+ struct arm_linux_process_info *next;
+ /* The process identifier. */
+ pid_t pid;
+ /* Hardware break-/watchpoints state information. */
+ struct arm_linux_debug_reg_state state;
- for (i = 0; VEC_iterate (arm_linux_thread_points_p, arm_threads, i, t); ++i)
- {
- if (t->tid == tid)
- return t;
- }
+};
+
+/* Per-thread arch-specific data we want to keep. */
+struct arch_lwp_info
+{
+ /* Non-zero if our copy differs from what's recorded in the thread. */
+ char bpts_changed[MAX_BPTS];
+ char wpts_changed[MAX_WPTS];
+};
+
+static struct arm_linux_process_info *arm_linux_process_list = NULL;
+
+/* Find process data for process PID. */
+
+static struct arm_linux_process_info *
+arm_linux_find_process_pid (pid_t pid)
+{
+ struct arm_linux_process_info *proc;
+
+ for (proc = arm_linux_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 arm_linux_process_info *
+arm_linux_add_process (pid_t pid)
+{
+ struct arm_linux_process_info *proc;
- t = NULL;
+ proc = xcalloc (1, sizeof (*proc));
+ proc->pid = pid;
- if (alloc_new)
+ proc->next = arm_linux_process_list;
+ arm_linux_process_list = proc;
+
+ return proc;
+}
+
+/* Get data specific info for process PID, creating it if necessary.
+ Never returns NULL. */
+
+static struct arm_linux_process_info *
+arm_linux_process_info_get (pid_t pid)
+{
+ struct arm_linux_process_info *proc;
+
+ proc = arm_linux_find_process_pid (pid);
+ if (proc == NULL)
+ proc = arm_linux_add_process (pid);
+
+ return proc;
+}
+
+/* Called whenever GDB is no longer debugging process PID. It deletes
+ data structures that keep track of debug register state. */
+
+static void
+arm_linux_forget_process (pid_t pid)
+{
+ struct arm_linux_process_info *proc, **proc_link;
+
+ proc = arm_linux_process_list;
+ proc_link = &arm_linux_process_list;
+
+ while (proc != NULL)
+ {
+ if (proc->pid == pid)
{
- t = xmalloc (sizeof (struct arm_linux_thread_points));
- t->tid = tid;
- t->bpts = xzalloc (arm_linux_get_hw_breakpoint_count ()
- * sizeof (struct arm_linux_hw_breakpoint));
- t->wpts = xzalloc (arm_linux_get_hw_watchpoint_count ()
- * sizeof (struct arm_linux_hw_breakpoint));
- VEC_safe_push (arm_linux_thread_points_p, arm_threads, t);
+ *proc_link = proc->next;
+
+ xfree (proc);
+ return;
}
- return t;
+ proc_link = &proc->next;
+ proc = *proc_link;
+ }
+}
+
+/* Get hardware break-/watchpoint state for process PID. */
+
+static struct arm_linux_debug_reg_state *
+arm_linux_get_debug_reg_state (pid_t pid)
+{
+ return &arm_linux_process_info_get (pid)->state;
}
/* Initialize an ARM hardware break-/watch-point control register value.
@@ -951,45 +1035,72 @@ arm_linux_hw_breakpoint_equal (const struct arm_linux_hw_breakpoint *p1,
return p1->address == p2->address && p1->control == p2->control;
}
+/* Callback to mark a watch-/breakpoint to be updated in all threads of
+ the current process. */
+
+struct update_registers_data
+{
+ int watch;
+ int index;
+};
+
+static int
+update_registers_callback (struct lwp_info *lwp, void *arg)
+{
+ struct update_registers_data *data = (struct update_registers_data *) arg;
+
+ if (lwp->arch_private == NULL)
+ lwp->arch_private = XCNEW (struct arch_lwp_info);
+
+ /* The actual update is done later just before resuming the lwp,
+ we just mark that the registers need updating. */
+ if (data->watch)
+ lwp->arch_private->wpts_changed[data->index] = 1;
+ else
+ lwp->arch_private->bpts_changed[data->index] = 1;
+
+ /* If the lwp isn't stopped, force it to momentarily pause, so
+ we can update its breakpoint registers. */
+ if (!lwp->stopped)
+ linux_stop_lwp (lwp);
+
+ return 0;
+}
+
/* Insert the hardware breakpoint (WATCHPOINT = 0) or watchpoint (WATCHPOINT
=1) BPT for thread TID. */
static void
arm_linux_insert_hw_breakpoint1 (const struct arm_linux_hw_breakpoint* bpt,
- int tid, int watchpoint)
+ int watchpoint)
{
- struct arm_linux_thread_points *t = arm_linux_find_breakpoints_by_tid (tid, 1);
+ int pid;
+ ptid_t pid_ptid;
gdb_byte count, i;
struct arm_linux_hw_breakpoint* bpts;
- int dir;
+ struct update_registers_data data;
- gdb_assert (t != NULL);
+ pid = ptid_get_pid (inferior_ptid);
+ pid_ptid = pid_to_ptid (pid);
if (watchpoint)
{
count = arm_linux_get_hw_watchpoint_count ();
- bpts = t->wpts;
- dir = -1;
+ bpts = arm_linux_get_debug_reg_state (pid)->wpts;
}
else
{
count = arm_linux_get_hw_breakpoint_count ();
- bpts = t->bpts;
- dir = 1;
+ bpts = arm_linux_get_debug_reg_state (pid)->bpts;
}
for (i = 0; i < count; ++i)
if (!arm_hwbp_control_is_enabled (bpts[i].control))
{
- errno = 0;
- if (ptrace (PTRACE_SETHBPREGS, tid, dir * ((i << 1) + 1),
- &bpt->address) < 0)
- perror_with_name (_("Unexpected error setting breakpoint address"));
- if (ptrace (PTRACE_SETHBPREGS, tid, dir * ((i << 1) + 2),
- &bpt->control) < 0)
- perror_with_name (_("Unexpected error setting breakpoint"));
-
- memcpy (bpts + i, bpt, sizeof (struct arm_linux_hw_breakpoint));
- break;
+ data.watch = watchpoint;
+ data.index = i;
+ bpts[i] = *bpt;
+ iterate_over_lwps (pid_ptid, update_registers_callback, &data);
+ break;
}
gdb_assert (i != count);
@@ -999,37 +1110,36 @@ arm_linux_insert_hw_breakpoint1 (const struct arm_linux_hw_breakpoint* bpt,
(WATCHPOINT = 1) BPT for thread TID. */
static void
arm_linux_remove_hw_breakpoint1 (const struct arm_linux_hw_breakpoint *bpt,
- int tid, int watchpoint)
+ int watchpoint)
{
- struct arm_linux_thread_points *t = arm_linux_find_breakpoints_by_tid (tid, 0);
+ int pid;
gdb_byte count, i;
- struct arm_linux_hw_breakpoint *bpts;
- int dir;
+ ptid_t pid_ptid;
+ struct arm_linux_hw_breakpoint* bpts;
+ struct update_registers_data data;
- gdb_assert (t != NULL);
+ pid = ptid_get_pid (inferior_ptid);
+ pid_ptid = pid_to_ptid (pid);
if (watchpoint)
{
count = arm_linux_get_hw_watchpoint_count ();
- bpts = t->wpts;
- dir = -1;
+ bpts = arm_linux_get_debug_reg_state (pid)->wpts;
}
else
{
count = arm_linux_get_hw_breakpoint_count ();
- bpts = t->bpts;
- dir = 1;
+ bpts = arm_linux_get_debug_reg_state (pid)->bpts;
}
for (i = 0; i < count; ++i)
if (arm_linux_hw_breakpoint_equal (bpt, bpts + i))
{
- errno = 0;
- bpts[i].control = arm_hwbp_control_disable (bpts[i].control);
- if (ptrace (PTRACE_SETHBPREGS, tid, dir * ((i << 1) + 2),
- &bpts[i].control) < 0)
- perror_with_name (_("Unexpected error clearing breakpoint"));
- break;
+ data.watch = watchpoint;
+ data.index = i;
+ bpts[i].control = arm_hwbp_control_disable (bpts[i].control);
+ iterate_over_lwps (pid_ptid, update_registers_callback, &data);
+ break;
}
gdb_assert (i != count);
@@ -1048,8 +1158,8 @@ arm_linux_insert_hw_breakpoint (struct target_ops *self,
return -1;
arm_linux_hw_breakpoint_initialize (gdbarch, bp_tgt, &p);
- ALL_LWPS (lp)
- arm_linux_insert_hw_breakpoint1 (&p, ptid_get_lwp (lp->ptid), 0);
+
+ arm_linux_insert_hw_breakpoint1 (&p, 0);
return 0;
}
@@ -1067,8 +1177,8 @@ arm_linux_remove_hw_breakpoint (struct target_ops *self,
return -1;
arm_linux_hw_breakpoint_initialize (gdbarch, bp_tgt, &p);
- ALL_LWPS (lp)
- arm_linux_remove_hw_breakpoint1 (&p, ptid_get_lwp (lp->ptid), 0);
+
+ arm_linux_remove_hw_breakpoint1 (&p, 0);
return 0;
}
@@ -1120,8 +1230,8 @@ arm_linux_insert_watchpoint (struct target_ops *self,
return -1;
arm_linux_hw_watchpoint_initialize (addr, len, rw, &p);
- ALL_LWPS (lp)
- arm_linux_insert_hw_breakpoint1 (&p, ptid_get_lwp (lp->ptid), 1);
+
+ arm_linux_insert_hw_breakpoint1 (&p, 1);
return 0;
}
@@ -1139,8 +1249,8 @@ arm_linux_remove_watchpoint (struct target_ops *self,
return -1;
arm_linux_hw_watchpoint_initialize (addr, len, rw, &p);
- ALL_LWPS (lp)
- arm_linux_remove_hw_breakpoint1 (&p, ptid_get_lwp (lp->ptid), 1);
+
+ arm_linux_remove_hw_breakpoint1 (&p, 1);
return 0;
}
@@ -1196,63 +1306,100 @@ arm_linux_watchpoint_addr_within_range (struct target_ops *target,
static void
arm_linux_new_thread (struct lwp_info *lp)
{
- int tid = ptid_get_lwp (lp->ptid);
- const struct arm_linux_hwbp_cap *info = arm_linux_get_hwbp_cap ();
+ int i;
+ struct arch_lwp_info *info = XCNEW (struct arch_lwp_info);
+
+ /* Mark that all the hardware breakpoint/watchpoint register pairs
+ for this thread need to be initialized. */
- if (info != NULL)
+ for (i = 0; i < MAX_BPTS; i++)
{
- int i;
- struct arm_linux_thread_points *p;
- struct arm_linux_hw_breakpoint *bpts;
-
- if (VEC_empty (arm_linux_thread_points_p, arm_threads))
- return;
-
- /* Get a list of breakpoints from any thread. */
- p = VEC_last (arm_linux_thread_points_p, arm_threads);
-
- /* Copy that thread's breakpoints and watchpoints to the new thread. */
- for (i = 0; i < info->bp_count; i++)
- if (arm_hwbp_control_is_enabled (p->bpts[i].control))
- arm_linux_insert_hw_breakpoint1 (p->bpts + i, tid, 0);
- for (i = 0; i < info->wp_count; i++)
- if (arm_hwbp_control_is_enabled (p->wpts[i].control))
- arm_linux_insert_hw_breakpoint1 (p->wpts + i, tid, 1);
+ info->bpts_changed[i] = 1;
+ info->wpts_changed[i] = 1;
}
+
+ lp->arch_private = info;
}
-/* Handle thread exit. Tidy up the memory that has been allocated for the
- thread. */
+/* Called when resuming a thread.
+ The hardware debug registers are updated when there is any change. */
+
static void
-arm_linux_thread_exit (struct thread_info *tp, int silent)
+arm_linux_prepare_to_resume (struct lwp_info *lwp)
{
- const struct arm_linux_hwbp_cap *info = arm_linux_get_hwbp_cap ();
+ int pid, i;
+ struct arm_linux_hw_breakpoint *bpts, *wpts;
+ struct arch_lwp_info *arm_lwp_info = lwp->arch_private;
+
+ pid = ptid_get_lwp (lwp->ptid);
+ bpts = arm_linux_get_debug_reg_state (ptid_get_pid (lwp->ptid))->bpts;
+ wpts = arm_linux_get_debug_reg_state (ptid_get_pid (lwp->ptid))->wpts;
+
+ /* NULL means this is the main thread still going through the shell,
+ or, no watchpoint has been set yet. In that case, there's
+ nothing to do. */
+ if (arm_lwp_info == NULL)
+ return;
- if (info != NULL)
- {
- int i;
- int tid = ptid_get_lwp (tp->ptid);
- struct arm_linux_thread_points *t = NULL, *p;
+ for (i = 0; i < arm_linux_get_hw_breakpoint_count (); i++)
+ if (arm_lwp_info->bpts_changed[i])
+ {
+ errno = 0;
+ if (arm_hwbp_control_is_enabled (bpts[i].control))
+ if (ptrace (PTRACE_SETHBPREGS, pid,
+ (PTRACE_TYPE_ARG3) ((i << 1) + 1), &bpts[i].address) < 0)
+ perror_with_name (_("Unexpected error setting breakpoint"));
+
+ if (bpts[i].control != 0)
+ if (ptrace (PTRACE_SETHBPREGS, pid,
+ (PTRACE_TYPE_ARG3) ((i << 1) + 2), &bpts[i].control) < 0)
+ perror_with_name (_("Unexpected error setting breakpoint"));
+
+ arm_lwp_info->bpts_changed[i] = 0;
+ }
- for (i = 0;
- VEC_iterate (arm_linux_thread_points_p, arm_threads, i, p); i++)
- {
- if (p->tid == tid)
- {
- t = p;
- break;
- }
- }
+ for (i = 0; i < arm_linux_get_hw_watchpoint_count (); i++)
+ if (arm_lwp_info->wpts_changed[i])
+ {
+ errno = 0;
+ if (arm_hwbp_control_is_enabled (wpts[i].control))
+ if (ptrace (PTRACE_SETHBPREGS, pid,
+ (PTRACE_TYPE_ARG3) -((i << 1) + 1), &wpts[i].address) < 0)
+ perror_with_name (_("Unexpected error setting watchpoint"));
+
+ if (wpts[i].control != 0)
+ if (ptrace (PTRACE_SETHBPREGS, pid,
+ (PTRACE_TYPE_ARG3) -((i << 1) + 2), &wpts[i].control) < 0)
+ perror_with_name (_("Unexpected error setting watchpoint"));
+
+ arm_lwp_info->wpts_changed[i] = 0;
+ }
+}
+
+/* linux_nat_new_fork hook. */
+
+static void
+arm_linux_new_fork (struct lwp_info *parent, pid_t child_pid)
+{
+ pid_t parent_pid;
+ struct arm_linux_debug_reg_state *parent_state;
+ struct arm_linux_debug_reg_state *child_state;
- if (t == NULL)
- return;
+ /* NULL means no watchpoint has ever been set in the parent. In
+ that case, there's nothing to do. */
+ if (parent->arch_private == NULL)
+ return;
- VEC_unordered_remove (arm_linux_thread_points_p, arm_threads, i);
+ /* GDB core assumes the child inherits the watchpoints/hw
+ breakpoints of the parent, and will remove them all from the
+ forked off process. Copy the debug registers mirrors into the
+ new process so that all breakpoints and watchpoints can be
+ removed together. */
- xfree (t->bpts);
- xfree (t->wpts);
- xfree (t);
- }
+ parent_pid = ptid_get_pid (parent->ptid);
+ parent_state = arm_linux_get_debug_reg_state (parent_pid);
+ child_state = arm_linux_get_debug_reg_state (child_pid);
+ *child_state = *parent_state;
}
void _initialize_arm_linux_nat (void);
@@ -1285,7 +1432,11 @@ _initialize_arm_linux_nat (void)
/* Register the target. */
linux_nat_add_target (t);
- /* Handle thread creation and exit */
- observer_attach_thread_exit (arm_linux_thread_exit);
+ /* Handle thread creation and exit. */
linux_nat_set_new_thread (t, arm_linux_new_thread);
+ linux_nat_set_prepare_to_resume (t, arm_linux_prepare_to_resume);
+
+ /* Handle process creation and exit. */
+ linux_nat_set_new_fork (t, arm_linux_new_fork);
+ linux_nat_set_forget_process (t, arm_linux_forget_process);
}