Add support for enabling and disabling tracepoints while a trace

experiment is still running.

gdb/
	* breakpoint.c (disable_breakpoint): Disable all locations
	associated with a tracepoint on target if a trace experiment is
	running.
	(disable_command): Disable a specific tracepoint location on target if
	a trace	experiment is running.
	(do_enable_breakpoint): Enable all locations associated with a
	tracepoint on target if a trace experiment is running.
	(enable_command) Enable a specific tracepoint location on target if a
	trace experiment is running.
	* target.c (update_current_target): Add INHERIT and de_fault clauses for
	to_supports_enable_disable_tracepoint, to_enable_tracepoint and
	to_disable_tracepoint.
	* target.h: Add declaration of struct bp_location.
	(struct target_ops): Add new functions
	to_supports_enable_disable_tracepoint, to_enable_tracepoint and
	to_disable_tracepoint to target operations.
	(target_supports_enable_disable_tracepoint): New macro.
	(target_enable_tracepoint): New macro.
	(target_disable_tracepoint): New macro.
	* remote.c (struct remote_state): Add new field.
	(remote_enable_disable_tracepoint_feature): New.
	(remote_protocol_features): Add new entry.
	(remote_supports_enable_disable_tracepoint): New.
	(remote_enable_tracepoint): New.
	(remote_disable_tracepoint): New.
	(init_remote_ops): Add remote_enable_tracepoint,
	remote_disable_tracepoint and remote_supports_enable_disable_tracepoint
	to remote operations.
	* tracepoint.c (start_tracing): Allow tracing to start without any
	tracepoints enabled with just a warning if they can be re-enabled
	later.
	* NEWS: Add news item for the new behaviour of the enable and disable
	GDB commands when applied to tracepoints.
	Add news items for the new remote packets QTEnable and QTDisable.

gdb/doc/
	* gdb.texinfo: Document change in the behaviour of the enable and
	disable GDB commands when applied to tracepoints.
	Document the EnableDisableTracepoints remote stub feature.
	Document QTEnable and QTDisable in the list of tracepoint packets.

gdb/gdbserver/
	* server.c (handle_query): Add EnableDisableTracepoints to the list
	of supported features.
	* tracepoint.c (clear_installed_tracepoints): Uninstall	disabled
	tracepoints.
	(cmd_qtenable_disable): New.
	(cmd_qtstart): Install tracepoints even if disabled.
	(handle_tracepoint_general_set): Add call to cmd_qtenable_disable on
	receiving a QTEnable or QTDisable packet.
	(gdb_collect): Skip data collection if fast tracepoint is disabled.
	(ust_marker_to_static_tracepoint): Do not ignore disabled static
	tracepoints.
	(gdb_probe): Skip data collection if static tracepoint is disabled.
This commit is contained in:
Kwok Yeung 2011-05-12 12:09:17 +00:00
parent de1491f042
commit d248b706a3
12 changed files with 334 additions and 16 deletions

View File

@ -1,3 +1,40 @@
2011-05-12 Kwok Cheung Yeung <kcy@codesourcery.com>
* breakpoint.c (disable_breakpoint): Disable all locations
associated with a tracepoint on target if a trace experiment is
running.
(disable_command): Disable a specific tracepoint location on target if
a trace experiment is running.
(do_enable_breakpoint): Enable all locations associated with a
tracepoint on target if a trace experiment is running.
(enable_command) Enable a specific tracepoint location on target if a
trace experiment is running.
* target.c (update_current_target): Add INHERIT and de_fault clauses for
to_supports_enable_disable_tracepoint, to_enable_tracepoint and
to_disable_tracepoint.
* target.h: Add declaration of struct bp_location.
(struct target_ops): Add new functions
to_supports_enable_disable_tracepoint, to_enable_tracepoint and
to_disable_tracepoint to target operations.
(target_supports_enable_disable_tracepoint): New macro.
(target_enable_tracepoint): New macro.
(target_disable_tracepoint): New macro.
* remote.c (struct remote_state): Add new field.
(remote_enable_disable_tracepoint_feature): New.
(remote_protocol_features): Add new entry.
(remote_supports_enable_disable_tracepoint): New.
(remote_enable_tracepoint): New.
(remote_disable_tracepoint): New.
(init_remote_ops): Add remote_enable_tracepoint,
remote_disable_tracepoint and remote_supports_enable_disable_tracepoint
to remote operations.
* tracepoint.c (start_tracing): Allow tracing to start without any
tracepoints enabled with just a warning if they can be re-enabled
later.
* NEWS: Add news item for the new behaviour of the enable and disable
GDB commands when applied to tracepoints.
Add news items for the new remote packets QTEnable and QTDisable.
2011-05-11 Jan Kratochvil <jan.kratochvil@redhat.com>
* config.in: Regenerate.

View File

@ -27,6 +27,23 @@ watch EXPRESSION mask MASK_VALUE
The watch command now supports the mask argument which allows creation
of masked watchpoints, if the current architecture supports this feature.
* Tracepoints can now be enabled and disabled at any time after a trace
experiment has been started using the standard "enable" and "disable"
commands. It is now possible to start a trace experiment with no enabled
tracepoints; GDB will display a warning, but will allow the experiment to
begin, assuming that tracepoints will be enabled as needed while the trace
is running.
* New remote packets
QTEnable
Dynamically enable a tracepoint in a started trace experiment.
QTDisable
Dynamically disable a tracepoint in a started trace experiment.
*** Changes in GDB 7.3
* GDB has a new command: "thread find [REGEXP]".

View File

@ -11685,6 +11685,15 @@ disable_breakpoint (struct breakpoint *bpt)
bpt->enable_state = bp_disabled;
if (target_supports_enable_disable_tracepoint ()
&& current_trace_status ()->running && is_tracepoint (bpt))
{
struct bp_location *location;
for (location = bpt->loc; location; location = location->next)
target_disable_tracepoint (location);
}
update_global_location_list (0);
observer_notify_breakpoint_modified (bpt);
@ -11714,7 +11723,13 @@ disable_command (char *args, int from_tty)
{
struct bp_location *loc = find_location_by_number (args);
if (loc)
loc->enabled = 0;
{
loc->enabled = 0;
if (target_supports_enable_disable_tracepoint ()
&& current_trace_status ()->running && loc->owner
&& is_tracepoint (loc->owner))
target_disable_tracepoint (loc);
}
update_global_location_list (0);
}
else
@ -11762,6 +11777,16 @@ do_enable_breakpoint (struct breakpoint *bpt, enum bpdisp disposition)
if (bpt->enable_state != bp_permanent)
bpt->enable_state = bp_enabled;
if (target_supports_enable_disable_tracepoint ()
&& current_trace_status ()->running && is_tracepoint (bpt))
{
struct bp_location *location;
for (location = bpt->loc; location; location = location->next)
target_enable_tracepoint (location);
}
bpt->disposition = disposition;
update_global_location_list (1);
breakpoints_changed ();
@ -11804,7 +11829,13 @@ enable_command (char *args, int from_tty)
{
struct bp_location *loc = find_location_by_number (args);
if (loc)
loc->enabled = 1;
{
loc->enabled = 1;
if (target_supports_enable_disable_tracepoint ()
&& current_trace_status ()->running && loc->owner
&& is_tracepoint (loc->owner))
target_enable_tracepoint (loc);
}
update_global_location_list (1);
}
else

View File

@ -1,3 +1,10 @@
2011-05-12 Kwok Cheung Yeung <kcy@codesourcery.com>
* gdb.texinfo: Document change in the behaviour of the enable and
disable GDB commands when applied to tracepoints.
Document the EnableDisableTracepoints remote stub feature.
Document QTEnable and QTDisable in the list of tracepoint packets.
2011-05-11 Jan Kratochvil <jan.kratochvil@redhat.com>
* Makefile.in (GDB_DOC_SOURCE_INCLUDES): Rename inc-hist.texinfo to

View File

@ -10026,14 +10026,20 @@ These commands are deprecated; they are equivalent to plain @code{disable} and @
@item disable tracepoint @r{[}@var{num}@r{]}
Disable tracepoint @var{num}, or all tracepoints if no argument
@var{num} is given. A disabled tracepoint will have no effect during
the next trace experiment, but it is not forgotten. You can re-enable
a trace experiment, but it is not forgotten. You can re-enable
a disabled tracepoint using the @code{enable tracepoint} command.
If the command is issued during a trace experiment and the debug target
has support for disabling tracepoints during a trace experiment, then the
change will be effective immediately. Otherwise, it will be applied to the
next trace experiment.
@kindex enable tracepoint
@item enable tracepoint @r{[}@var{num}@r{]}
Enable tracepoint @var{num}, or all tracepoints. The enabled
tracepoints will become effective the next time a trace experiment is
run.
Enable tracepoint @var{num}, or all tracepoints. If this command is
issued during a trace experiment and the debug target supports enabling
tracepoints during a trace experiment, then the enabled tracepoints will
become effective immediately. Otherwise, they will become effective the
next time a trace experiment is run.
@end table
@node Tracepoint Passcounts
@ -33627,6 +33633,11 @@ These are the currently defined stub features and their properties:
@tab @samp{-}
@tab No
@item @samp{EnableDisableTracepoints}
@tab No
@tab @samp{-}
@tab No
@end multitable
These are the currently defined stub features, in more detail:
@ -33739,6 +33750,11 @@ The remote stub understands the @samp{QAllow} packet.
@cindex static tracepoints, in remote protocol
The remote stub supports static tracepoints.
@item EnableDisableTracepoints
The remote stub supports the @samp{QTEnable} (@pxref{QTEnable}) and
@samp{QTDisable} (@pxref{QTDisable}) packets that allow tracepoints
to be enabled and disabled while a trace experiment is running.
@end table
@item qSymbol::
@ -33819,6 +33835,8 @@ packets.)
@item qTsV
@itemx QTStart
@itemx QTStop
@itemx QTEnable
@itemx QTDisable
@itemx QTinit
@itemx QTro
@itemx qTStatus
@ -34308,6 +34326,18 @@ instruction reply packet}).
@item QTStop
End the tracepoint experiment. Stop collecting trace frames.
@item QTEnable:@var{n}:@var{addr}
@anchor{QTEnable}
Enable tracepoint @var{n} at address @var{addr} in a started tracepoint
experiment. If the tracepoint was previously disabled, then collection
of data from it will resume.
@item QTDisable:@var{n}:@var{addr}
@anchor{QTDisable}
Disable tracepoint @var{n} at address @var{addr} in a started tracepoint
experiment. No more data will be collected from the tracepoint unless
@samp{QTEnable:@var{n}:@var{addr}} is subsequently issued.
@item QTinit
Clear the table of tracepoints, and empty the trace frame buffer.

View File

@ -1,3 +1,18 @@
2011-05-12 Kwok Cheung Yeung <kcy@codesourcery.com>
* server.c (handle_query): Add EnableDisableTracepoints to the list
of supported features.
* tracepoint.c (clear_installed_tracepoints): Uninstall disabled
tracepoints.
(cmd_qtenable_disable): New.
(cmd_qtstart): Install tracepoints even if disabled.
(handle_tracepoint_general_set): Add call to cmd_qtenable_disable on
receiving a QTEnable or QTDisable packet.
(gdb_collect): Skip data collection if fast tracepoint is disabled.
(ust_marker_to_static_tracepoint): Do not ignore disabled static
tracepoints.
(gdb_probe): Skip data collection if static tracepoint is disabled.
2011-05-10 Doug Evans <dje@google.com>
* thread-db.c (thread_db_handle_monitor_command): Handle elided path.

View File

@ -1540,6 +1540,7 @@ handle_query (char *own_buf, int packet_len, int *new_packet_len_p)
strcat (own_buf, ";StaticTracepoints+");
strcat (own_buf, ";qXfer:statictrace:read+");
strcat (own_buf, ";qXfer:traceframe-info:read+");
strcat (own_buf, ";EnableDisableTracepoints+");
}
return;

View File

@ -2214,9 +2214,6 @@ clear_installed_tracepoints (void)
/* Restore any bytes overwritten by tracepoints. */
for (tpoint = tracepoints; tpoint; tpoint = tpoint->next)
{
if (!tpoint->enabled)
continue;
/* Catch the case where we might try to remove a tracepoint that
was never actually installed. */
if (tpoint->handle == NULL)
@ -2454,6 +2451,73 @@ cmd_qtdv (char *own_buf)
write_ok (own_buf);
}
static void
cmd_qtenable_disable (char *own_buf, int enable)
{
char *packet = own_buf;
ULONGEST num, addr;
struct tracepoint *tp;
packet += strlen (enable ? "QTEnable:" : "QTDisable:");
packet = unpack_varlen_hex (packet, &num);
++packet; /* skip a colon */
packet = unpack_varlen_hex (packet, &addr);
tp = find_tracepoint (num, addr);
if (tp)
{
if ((enable && tp->enabled) || (!enable && !tp->enabled))
{
trace_debug ("Tracepoint %d at 0x%s is already %s",
(int) num, paddress (addr),
enable ? "enabled" : "disabled");
write_ok (own_buf);
return;
}
trace_debug ("%s tracepoint %d at 0x%s",
enable ? "Enabling" : "Disabling",
(int) num, paddress (addr));
tp->enabled = enable;
if (tp->type == fast_tracepoint || tp->type == static_tracepoint)
{
int ret;
int offset = offsetof (struct tracepoint, enabled);
CORE_ADDR obj_addr = tp->obj_addr_on_target + offset;
ret = prepare_to_access_memory ();
if (ret)
{
trace_debug ("Failed to temporarily stop inferior threads");
write_enn (own_buf);
return;
}
ret = write_inferior_integer (obj_addr, enable);
done_accessing_memory ();
if (ret)
{
trace_debug ("Cannot write enabled flag into "
"inferior process memory");
write_enn (own_buf);
return;
}
}
write_ok (own_buf);
}
else
{
trace_debug ("Tracepoint %d at 0x%s not found",
(int) num, paddress (addr));
write_enn (own_buf);
}
}
static void
cmd_qtv (char *own_buf)
{
@ -2719,9 +2783,6 @@ cmd_qtstart (char *packet)
/* Ensure all the hit counts start at zero. */
tpoint->hit_count = 0;
if (!tpoint->enabled)
continue;
if (tpoint->type == trap_tracepoint)
{
++slow_tracepoint_count;
@ -3461,6 +3522,16 @@ handle_tracepoint_general_set (char *packet)
cmd_qtdpsrc (packet);
return 1;
}
else if (strncmp ("QTEnable:", packet, strlen ("QTEnable:")) == 0)
{
cmd_qtenable_disable (packet, 1);
return 1;
}
else if (strncmp ("QTDisable:", packet, strlen ("QTDisable:")) == 0)
{
cmd_qtenable_disable (packet, 0);
return 1;
}
else if (strncmp ("QTDV:", packet, strlen ("QTDV:")) == 0)
{
cmd_qtdv (packet);
@ -5340,6 +5411,9 @@ gdb_collect (struct tracepoint *tpoint, unsigned char *regs)
if (!tracing)
return;
if (!tpoint->enabled)
return;
ctx.base.type = fast_tracepoint;
ctx.regs = regs;
ctx.regcache_initted = 0;
@ -6598,7 +6672,7 @@ ust_marker_to_static_tracepoint (const struct marker *mdata)
for (tpoint = tracepoints; tpoint; tpoint = tpoint->next)
{
if (!tpoint->enabled || tpoint->type != static_tracepoint)
if (tpoint->type != static_tracepoint)
continue;
if (tpoint->address == (uintptr_t) mdata->location)
@ -6653,6 +6727,12 @@ gdb_probe (const struct marker *mdata, void *probe_private,
return;
}
if (!tpoint->enabled)
{
trace_debug ("gdb_probe: tracepoint disabled");
return;
}
ctx.tpoint = tpoint;
trace_debug ("gdb_probe: collecting marker: "

View File

@ -329,6 +329,10 @@ struct remote_state
disconnected. */
int disconnected_tracing;
/* True if the stub reports support for enabling and disabling
tracepoints while a trace experiment is running. */
int enable_disable_tracepoints;
/* Nonzero if the user has pressed Ctrl-C, but the target hasn't
responded to that. */
int ctrlc_pending_p;
@ -3689,6 +3693,16 @@ remote_disconnected_tracing_feature (const struct protocol_feature *feature,
rs->disconnected_tracing = (support == PACKET_ENABLE);
}
static void
remote_enable_disable_tracepoint_feature (const struct protocol_feature *feature,
enum packet_support support,
const char *value)
{
struct remote_state *rs = get_remote_state ();
rs->enable_disable_tracepoints = (support == PACKET_ENABLE);
}
static struct protocol_feature remote_protocol_features[] = {
{ "PacketSize", PACKET_DISABLE, remote_packet_size, -1 },
{ "qXfer:auxv:read", PACKET_DISABLE, remote_supported_packet,
@ -3735,6 +3749,8 @@ static struct protocol_feature remote_protocol_features[] = {
PACKET_TracepointSource },
{ "QAllow", PACKET_DISABLE, remote_supported_packet,
PACKET_QAllow },
{ "EnableDisableTracepoints", PACKET_DISABLE,
remote_enable_disable_tracepoint_feature, -1 },
};
static char *remote_support_xml;
@ -9648,6 +9664,14 @@ remote_supports_static_tracepoints (void)
return rs->static_tracepoints;
}
static int
remote_supports_enable_disable_tracepoint (void)
{
struct remote_state *rs = get_remote_state ();
return rs->enable_disable_tracepoints;
}
static void
remote_trace_init (void)
{
@ -9918,6 +9942,38 @@ remote_download_trace_state_variable (struct trace_state_variable *tsv)
error (_("Error on target while downloading trace state variable."));
}
static void
remote_enable_tracepoint (struct bp_location *location)
{
struct remote_state *rs = get_remote_state ();
char addr_buf[40];
sprintf_vma (addr_buf, location->address);
sprintf (rs->buf, "QTEnable:%x:%s", location->owner->number, addr_buf);
putpkt (rs->buf);
remote_get_noisy_reply (&rs->buf, &rs->buf_size);
if (*rs->buf == '\0')
error (_("Target does not support enabling tracepoints while a trace run is ongoing."));
if (strcmp (rs->buf, "OK") != 0)
error (_("Error on target while enabling tracepoint."));
}
static void
remote_disable_tracepoint (struct bp_location *location)
{
struct remote_state *rs = get_remote_state ();
char addr_buf[40];
sprintf_vma (addr_buf, location->address);
sprintf (rs->buf, "QTDisable:%x:%s", location->owner->number, addr_buf);
putpkt (rs->buf);
remote_get_noisy_reply (&rs->buf, &rs->buf_size);
if (*rs->buf == '\0')
error (_("Target does not support disabling tracepoints while a trace run is ongoing."));
if (strcmp (rs->buf, "OK") != 0)
error (_("Error on target while disabling tracepoint."));
}
static void
remote_trace_set_readonly_regions (void)
{
@ -10308,10 +10364,13 @@ Specify the serial device it is connected to\n\
remote_ops.to_terminal_ours = remote_terminal_ours;
remote_ops.to_supports_non_stop = remote_supports_non_stop;
remote_ops.to_supports_multi_process = remote_supports_multi_process;
remote_ops.to_supports_enable_disable_tracepoint = remote_supports_enable_disable_tracepoint;
remote_ops.to_trace_init = remote_trace_init;
remote_ops.to_download_tracepoint = remote_download_tracepoint;
remote_ops.to_download_trace_state_variable
= remote_download_trace_state_variable;
remote_ops.to_enable_tracepoint = remote_enable_tracepoint;
remote_ops.to_disable_tracepoint = remote_disable_tracepoint;
remote_ops.to_trace_set_readonly_regions = remote_trace_set_readonly_regions;
remote_ops.to_trace_start = remote_trace_start;
remote_ops.to_get_trace_status = remote_get_trace_status;

View File

@ -659,9 +659,12 @@ update_current_target (void)
INHERIT (to_get_ada_task_ptid, t);
/* Do not inherit to_search_memory. */
INHERIT (to_supports_multi_process, t);
INHERIT (to_supports_enable_disable_tracepoint, t);
INHERIT (to_trace_init, t);
INHERIT (to_download_tracepoint, t);
INHERIT (to_download_trace_state_variable, t);
INHERIT (to_enable_tracepoint, t);
INHERIT (to_disable_tracepoint, t);
INHERIT (to_trace_set_readonly_regions, t);
INHERIT (to_trace_start, t);
INHERIT (to_get_trace_status, t);
@ -825,6 +828,9 @@ update_current_target (void)
de_fault (to_supports_multi_process,
(int (*) (void))
return_zero);
de_fault (to_supports_enable_disable_tracepoint,
(int (*) (void))
return_zero);
de_fault (to_trace_init,
(void (*) (void))
tcomplain);
@ -834,6 +840,12 @@ update_current_target (void)
de_fault (to_download_trace_state_variable,
(void (*) (struct trace_state_variable *))
tcomplain);
de_fault (to_enable_tracepoint,
(void (*) (struct bp_location *))
tcomplain);
de_fault (to_disable_tracepoint,
(void (*) (struct bp_location *))
tcomplain);
de_fault (to_trace_set_readonly_regions,
(void (*) (void))
tcomplain);

View File

@ -28,6 +28,7 @@ struct objfile;
struct ui_file;
struct mem_attrib;
struct target_ops;
struct bp_location;
struct bp_target_info;
struct regcache;
struct target_section_table;
@ -644,6 +645,10 @@ struct target_ops
simultaneously? */
int (*to_supports_multi_process) (void);
/* Does this target support enabling and disabling tracepoints while a trace
experiment is running? */
int (*to_supports_enable_disable_tracepoint) (void);
/* Determine current architecture of thread PTID.
The target is supposed to determine the architecture of the code where
@ -674,6 +679,12 @@ struct target_ops
/* Send full details of a trace state variable to the target. */
void (*to_download_trace_state_variable) (struct trace_state_variable *tsv);
/* Enable a tracepoint on the target. */
void (*to_enable_tracepoint) (struct bp_location *location);
/* Disable a tracepoint on the target. */
void (*to_disable_tracepoint) (struct bp_location *location);
/* Inform the target info of memory regions that are readonly
(such as text sections), and so it should return data from
those rather than look in the trace buffer. */
@ -873,6 +884,12 @@ struct address_space *target_thread_address_space (ptid_t);
#define target_supports_multi_process() \
(*current_target.to_supports_multi_process) ()
/* Returns true if this target can enable and disable tracepoints
while a trace experiment is running. */
#define target_supports_enable_disable_tracepoint() \
(*current_target.to_supports_enable_disable_tracepoint) ()
/* Invalidate all target dcaches. */
extern void target_dcache_invalidate (void);
@ -1457,6 +1474,12 @@ extern int target_search_memory (CORE_ADDR start_addr,
#define target_download_trace_state_variable(tsv) \
(*current_target.to_download_trace_state_variable) (tsv)
#define target_enable_tracepoint(loc) \
(*current_target.to_enable_tracepoint) (loc)
#define target_disable_tracepoint(loc) \
(*current_target.to_disable_tracepoint) (loc)
#define target_trace_start() \
(*current_target.to_trace_start) ()

View File

@ -1583,11 +1583,17 @@ start_tracing (void)
(t->type == bp_fast_tracepoint ? "fast " : ""), t->number);
}
/* No point in tracing with only disabled tracepoints. */
if (!any_enabled)
{
VEC_free (breakpoint_p, tp_vec);
error (_("No tracepoints enabled, not starting trace"));
if (target_supports_enable_disable_tracepoint ())
warning (_("No tracepoints enabled"));
else
{
/* No point in tracing with only disabled tracepoints that
cannot be re-enabled. */
VEC_free (breakpoint_p, tp_vec);
error (_("No tracepoints enabled, not starting trace"));
}
}
if (num_to_download <= 0)