This patch adds support for range stepping to GDBserver, teaching it
about vCont;r.
It'd be easy to enable this for all hardware single-step targets
without needing the linux_target_ops hook, however, at least PPC needs
special care, due to the fact that PPC atomic sequences can't be
hardware single-stepped through, a thing which GDBserver doesn't know
about. So this leaves the support limited to x86/x86_64.
gdb/
2013-05-23 Pedro Alves <palves@redhat.com>
* NEWS: Mention GDBserver range stepping support.
gdb/gdbserver/
2013-05-23 Yao Qi <yao@codesourcery.com>
Pedro Alves <palves@redhat.com>
* linux-low.c (lwp_in_step_range): New function.
(linux_wait_1): If the thread was range stepping and stopped
outside the stepping range, report the stop to GDB. Otherwise,
continue stepping. Add range stepping debug output.
(linux_set_resume_request): Copy the step range from the resume
request to the lwp.
(linux_supports_range_stepping): New.
(linux_target_ops) <supports_range_stepping>: Set to
linux_supports_range_stepping.
* linux-low.h (struct linux_target_ops)
<supports_range_stepping>: New field.
(struct lwp_info) <step_range_start, step_range_end>: New fields.
* linux-x86-low.c (x86_supports_range_stepping): New.
(the_low_target) <supports_range_stepping>: Set to
x86_supports_range_stepping.
* server.c (handle_v_cont): Handle 'r' action.
(handle_v_requests): Append ";r" if the target supports range
stepping.
* target.h (struct thread_resume) <step_range_start,
step_range_end>: New fields.
(struct target_ops) <supports_range_stepping>:
New field.
(target_supports_range_stepping): New macro.
+2013-05-23 Pedro Alves <palves@redhat.com>
+
+ * NEWS: Mention GDBserver range stepping support.
+
2013-05-23 Yao Qi <yao@codesourcery.com>
Pedro Alves <palves@redhat.com>
stub to step through an address range itself, without GDB
involvemement at each single-step.
+* New features in the GDB remote stub, GDBserver
+
+ ** GDBserver now supports target-assisted range stepping. Currently
+ enabled on x86/x86_64 GNU/Linux targets.
+
*** Changes in GDB 7.6
* Target record has been renamed to record-full.
+2013-05-23 Yao Qi <yao@codesourcery.com>
+ Pedro Alves <palves@redhat.com>
+
+ * linux-low.c (lwp_in_step_range): New function.
+ (linux_wait_1): If the thread was range stepping and stopped
+ outside the stepping range, report the stop to GDB. Otherwise,
+ continue stepping. Add range stepping debug output.
+ (linux_set_resume_request): Copy the step range from the resume
+ request to the lwp.
+ (linux_supports_range_stepping): New.
+ (linux_target_ops) <supports_range_stepping>: Set to
+ linux_supports_range_stepping.
+ * linux-low.h (struct linux_target_ops)
+ <supports_range_stepping>: New field.
+ (struct lwp_info) <step_range_start, step_range_end>: New fields.
+ * linux-x86-low.c (x86_supports_range_stepping): New.
+ (the_low_target) <supports_range_stepping>: Set to
+ x86_supports_range_stepping.
+ * server.c (handle_v_cont): Handle 'r' action.
+ (handle_v_requests): Append ";r" if the target supports range
+ stepping.
+ * target.h (struct thread_resume) <step_range_start,
+ step_range_end>: New fields.
+ (struct target_ops) <supports_range_stepping>:
+ New field.
+ (target_supports_range_stepping): New macro.
+
2013-05-17 Joel Brobecker <brobecker@adacore.com>
* lynx-low.c (lynx_resume): Fix null_ptid/minus_one_ptid
return the_low_target.install_fast_tracepoint_jump_pad != NULL;
}
+/* True if LWP is stopped in its stepping range. */
+
+static int
+lwp_in_step_range (struct lwp_info *lwp)
+{
+ CORE_ADDR pc = lwp->stop_pc;
+
+ return (pc >= lwp->step_range_start && pc < lwp->step_range_end);
+}
+
struct pending_signals
{
int signal;
int maybe_internal_trap;
int report_to_gdb;
int trace_event;
+ int in_step_range;
/* Translate generic target options into linux options. */
options = __WALL;
retry:
bp_explains_trap = 0;
trace_event = 0;
+ in_step_range = 0;
ourstatus->kind = TARGET_WAITKIND_IGNORE;
/* If we were only supposed to resume one thread, only wait for
goto retry;
}
- /* If GDB wanted this thread to single step, we always want to
- report the SIGTRAP, and let GDB handle it. Watchpoints should
- always be reported. So should signals we can't explain. A
- SIGTRAP we can't explain could be a GDB breakpoint --- we may or
- not support Z0 breakpoints. If we do, we're be able to handle
- GDB breakpoints on top of internal breakpoints, by handling the
- internal breakpoint and still reporting the event to GDB. If we
- don't, we're out of luck, GDB won't see the breakpoint hit. */
+ /* Note that all addresses are always "out of the step range" when
+ there's no range to begin with. */
+ in_step_range = lwp_in_step_range (event_child);
+
+ /* If GDB wanted this thread to single step, and the thread is out
+ of the step range, we always want to report the SIGTRAP, and let
+ GDB handle it. Watchpoints should always be reported. So should
+ signals we can't explain. A SIGTRAP we can't explain could be a
+ GDB breakpoint --- we may or not support Z0 breakpoints. If we
+ do, we're be able to handle GDB breakpoints on top of internal
+ breakpoints, by handling the internal breakpoint and still
+ reporting the event to GDB. If we don't, we're out of luck, GDB
+ won't see the breakpoint hit. */
report_to_gdb = (!maybe_internal_trap
- || current_inferior->last_resume_kind == resume_step
+ || (current_inferior->last_resume_kind == resume_step
+ && !in_step_range)
|| event_child->stopped_by_watchpoint
- || (!step_over_finished
+ || (!step_over_finished && !in_step_range
&& !bp_explains_trap && !trace_event)
|| (gdb_breakpoint_here (event_child->stop_pc)
&& gdb_condition_true_at_breakpoint (event_child->stop_pc)
fprintf (stderr, "Step-over finished.\n");
if (trace_event)
fprintf (stderr, "Tracepoint event.\n");
+ if (lwp_in_step_range (event_child))
+ fprintf (stderr, "Range stepping pc 0x%s [0x%s, 0x%s).\n",
+ paddress (event_child->stop_pc),
+ paddress (event_child->step_range_start),
+ paddress (event_child->step_range_end));
}
/* We're not reporting this breakpoint to GDB, so apply the
if (debug_threads)
{
if (current_inferior->last_resume_kind == resume_step)
- fprintf (stderr, "GDB wanted to single-step, reporting event.\n");
+ {
+ if (event_child->step_range_start == event_child->step_range_end)
+ fprintf (stderr, "GDB wanted to single-step, reporting event.\n");
+ else if (!lwp_in_step_range (event_child))
+ fprintf (stderr, "Out of step range, reporting event.\n");
+ }
if (event_child->stopped_by_watchpoint)
fprintf (stderr, "Stopped by watchpoint.\n");
if (gdb_breakpoint_here (event_child->stop_pc))
lwp->resume = &r->resume[ndx];
thread->last_resume_kind = lwp->resume->kind;
+ lwp->step_range_start = lwp->resume->step_range_start;
+ lwp->step_range_end = lwp->resume->step_range_end;
+
/* If we had a deferred signal to report, dequeue one now.
This can happen if LWP gets more than one signal while
trying to get out of a jump pad. */
return 1;
}
+static int
+linux_supports_range_stepping (void)
+{
+ if (*the_low_target.supports_range_stepping == NULL)
+ return 0;
+
+ return (*the_low_target.supports_range_stepping) ();
+}
+
/* Enumerate spufs IDs for process PID. */
static int
spu_enumerate_spu_ids (long pid, unsigned char *buf, CORE_ADDR offset, int len)
NULL,
NULL,
#endif
+ linux_supports_range_stepping,
};
static void
for use as a fast tracepoint. */
int (*get_min_fast_tracepoint_insn_len) (void);
+ /* Returns true if the low target supports range stepping. */
+ int (*supports_range_stepping) (void);
};
extern struct linux_target_ops the_low_target;
level on this process was a single-step. */
int stepping;
+ /* Range to single step within. This is a copy of the step range
+ passed along the last resume request. See 'struct
+ thread_resume'. */
+ CORE_ADDR step_range_start; /* Inclusive */
+ CORE_ADDR step_range_end; /* Exclusive */
+
/* If this flag is set, we need to set the event request flags the
next time we see this LWP stop. */
int must_set_ptrace_flags;
return &i386_emit_ops;
}
+static int
+x86_supports_range_stepping (void)
+{
+ return 1;
+}
+
/* This is initialized assuming an amd64 target.
x86_arch_setup will correct it for i386 or amd64 targets. */
x86_install_fast_tracepoint_jump_pad,
x86_emit_ops,
x86_get_min_fast_tracepoint_insn_len,
+ x86_supports_range_stepping,
};
{
p++;
+ memset (&resume_info[i], 0, sizeof resume_info[i]);
+
if (p[0] == 's' || p[0] == 'S')
resume_info[i].kind = resume_step;
+ else if (p[0] == 'r')
+ resume_info[i].kind = resume_step;
else if (p[0] == 'c' || p[0] == 'C')
resume_info[i].kind = resume_continue;
else if (p[0] == 't')
goto err;
resume_info[i].sig = gdb_signal_to_host (sig);
}
+ else if (p[0] == 'r')
+ {
+ char *p1;
+
+ p = p + 1;
+ p1 = strchr (p, ',');
+ decode_address (&resume_info[i].step_range_start, p, p1 - p);
+
+ p = p1 + 1;
+ p1 = strchr (p, ':');
+ decode_address (&resume_info[i].step_range_end, p, p1 - p);
+
+ p = p1;
+ }
else
{
- resume_info[i].sig = 0;
p = p + 1;
}
if (strncmp (own_buf, "vCont?", 6) == 0)
{
strcpy (own_buf, "vCont;c;C;s;S;t");
+ if (target_supports_range_stepping ())
+ {
+ own_buf = own_buf + strlen (own_buf);
+ strcpy (own_buf, ";r");
+ }
return;
}
}
linux; SuspendThread on win32). This is a host signal value (not
enum gdb_signal). */
int sig;
+
+ /* Range to single step within. Valid only iff KIND is resume_step.
+
+ Single-step once, and then continuing stepping as long as the
+ thread stops in this range. (If the range is empty
+ [STEP_RANGE_START == STEP_RANGE_END], then this is a single-step
+ request.) */
+ CORE_ADDR step_range_start; /* Inclusive */
+ CORE_ADDR step_range_end; /* Exclusive */
};
/* Generally, what has the program done? */
to break a cyclic dependency. */
void (*read_btrace) (struct btrace_target_info *, struct buffer *, int type);
+ /* Return true if target supports range stepping. */
+ int (*supports_range_stepping) (void);
};
extern struct target_ops *the_target;
#define target_read_btrace(tinfo, buffer, type) \
(*the_target->read_btrace) (tinfo, buffer, type)
+#define target_supports_range_stepping() \
+ (the_target->supports_range_stepping ? \
+ (*the_target->supports_range_stepping) () : 0)
+
/* Start non-stop mode, returns 0 on success, -1 on failure. */
int start_non_stop (int nonstop);
projects / binutils-gdb.git / commitdiff