btrace: support Intel(R) Processor Trace

Adds a new command "record btrace pt" to configure the kernel to use
Intel(R) Processor Trace instead of Branch Trace Strore.

The "record btrace" command chooses the tracing format automatically.

Intel(R) Processor Trace support requires Linux 4.1 and libipt.

gdb/
	* NEWS: Announce new commands "record btrace pt" and "record pt".
	Announce new options "set|show record btrace pt buffer-size".
	* btrace.c: Include "rsp-low.h".
	Include "inttypes.h".
	(btrace_add_pc): Add forward declaration.
	(pt_reclassify_insn, ftrace_add_pt, btrace_pt_readmem_callback)
	(pt_translate_cpu_vendor, btrace_finalize_ftrace_pt)
	(btrace_compute_ftrace_pt): New.
	(btrace_compute_ftrace): Support BTRACE_FORMAT_PT.
	(check_xml_btrace_version): Update version check.
	(parse_xml_raw, parse_xml_btrace_pt_config_cpu)
	(parse_xml_btrace_pt_raw, parse_xml_btrace_pt)
	(btrace_pt_config_cpu_attributes, btrace_pt_config_children)
	(btrace_pt_children): New.
	(btrace_children): Add support for "pt".
	(parse_xml_btrace_conf_pt, btrace_conf_pt_attributes): New.
	(btrace_conf_children): Add support for "pt".
	* btrace.h: Include "intel-pt.h".
	(btrace_pt_error): New.
	* common/btrace-common.c (btrace_format_string, btrace_data_fini)
	(btrace_data_empty): Support BTRACE_FORMAT_PT.
	* common/btrace-common.h (btrace_format): Add BTRACE_FORMAT_PT.
	(struct btrace_config_pt): New.
	(struct btrace_config)<pt>: New.
	(struct btrace_data_pt_config, struct btrace_data_pt): New.
	(struct btrace_data)<pt>: New.
	* features/btrace-conf.dtd (btrace-conf)<pt>: New.
	(pt): New.
	* features/btrace.dtd (btrace)<pt>: New.
	(pt, pt-config, cpu): New.
	* nat/linux-btrace.c (perf_event_read, perf_event_read_all)
	(perf_event_pt_event_type, kernel_supports_pt)
	(linux_supports_pt): New.
	(linux_supports_btrace): Support BTRACE_FORMAT_PT.
	(linux_enable_bts): Free tinfo on error.
	(linux_enable_pt): New.
	(linux_enable_btrace): Support BTRACE_FORMAT_PT.
	(linux_disable_pt): New.
	(linux_disable_btrace): Support BTRACE_FORMAT_PT.
	(linux_fill_btrace_pt_config, linux_read_pt): New.
	(linux_read_btrace): Support BTRACE_FORMAT_PT.
	* nat/linux-btrace.h (struct btrace_tinfo_pt): New.
	(struct btrace_target_info)<pt>: New.
	* record-btrace.c (set_record_btrace_pt_cmdlist)
	(show_record_btrace_pt_cmdlist): New.
	(record_btrace_print_pt_conf): New.
	(record_btrace_print_conf): Support BTRACE_FORMAT_PT.
	(btrace_ui_out_decode_error): Support BTRACE_FORMAT_PT.
	(cmd_record_btrace_pt_start): New.
	(cmd_record_btrace_start): Support BTRACE_FORMAT_PT.
	(cmd_set_record_btrace_pt, cmd_show_record_btrace_pt): New.
	(_initialize_record_btrace): Add new commands.
	* remote.c (PACKET_Qbtrace_pt, PACKET_Qbtrace_conf_pt_size): New.
	(remote_protocol_features): Add "Qbtrace:pt".
	Add "Qbtrace-conf:pt:size".
	(remote_supports_btrace): Support BTRACE_FORMAT_PT.
	(btrace_sync_conf): Support PACKET_Qbtrace_conf_pt_size.
	(remote_enable_btrace): Support BTRACE_FORMAT_PT.
	(_initialize_remote): Add new commands.

gdbserver/
	* linux-low.c: Include "rsp-low.h"
	(linux_low_encode_pt_config, linux_low_encode_raw): New.
	(linux_low_read_btrace): Support BTRACE_FORMAT_PT.
	(linux_low_btrace_conf): Support BTRACE_FORMAT_PT.
	(handle_btrace_enable_pt): New.
	(handle_btrace_general_set): Support "pt".
	(handle_btrace_conf_general_set): Support "pt:size".

doc/
	* gdb.texinfo (Process Record and Replay): Spell out that variables
	and registers are not available during btrace replay.
	Describe the new "record btrace pt" command.
	Describe the new "set|show record btrace pt buffer-size" options.
	(General Query Packets): Describe the new Qbtrace:pt and
	Qbtrace-conf:pt:size packets.
	Expand "bts" to "Branch Trace Store".
	Update the branch trace DTD.

1 files changed, 19 insertions, 0 deletions

diff --git a/gdb/NEWS b/gdb/NEWS
index 9900d7f..6e0fe6d 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -112,6 +112,10 @@ show mpx bound
 set mpx bound on i386 and amd64
    Support for bound table investigation on Intel(R) MPX enabled applications.
 
+record btrace pt
+record pt
+  Start branch trace recording using Intel(R) Processor Trace format.
+
 * New options
 
 set debug dwarf-die
@@ -163,6 +167,12 @@ set debug linux-namespaces
 show debug linux-namespaces
   Control display of debugging info regarding Linux namespaces.
 
+set|show record btrace pt buffer-size
+  Set and show the size of the ring buffer used for branch tracing in
+  Intel(R) Processor Trace format.
+  The obtained size may differ from the requested size.  Use "info
+  record" to see the obtained buffer size.
+
 * The command 'thread apply all' can now support new option '-ascending'
   to call its specified command for all threads in ascending order.
 
@@ -179,6 +189,15 @@ qXfer:btrace-conf:read
 Qbtrace-conf:bts:size
   Set the requested ring buffer size for branch tracing in BTS format.
 
+Qbtrace:pt
+  Enable Intel(R) Procesor Trace-based branch tracing for the current
+  process.  The remote stub reports support for this packet to GDB's
+  qSupported query.
+
+Qbtrace-conf:pt:size
+  Set the requested ring buffer size for branch tracing in Intel(R) Processor
+  Trace format.
+
 swbreak stop reason
   Indicates a memory breakpoint instruction was executed, irrespective
   of whether it was GDB that planted the breakpoint or the breakpoint