If GDB has been configured without libipt support, i.e. HAVE_LIBIPT is
undefined, and is running on a system that supports Intel(R) Processor Trace,
GDB will run into an internal error when trying to decode the trace.
(gdb) record btrace
(gdb) s
usage (name=0x7fffffffe954 "fib-64")
at src/fib.c:12
12 fprintf(stderr, "usage: %s <num>\n", name);
(gdb) info record
Active record target: record-btrace
Recording format: Intel(R) Processor Trace.
Buffer size: 16kB.
gdb/btrace.c:971: internal-error: Unexpected branch trace format.
A problem internal to GDB has been detected,
further debugging may prove unreliable.
Quit this debugging session? (y or n)
This requires a system with Linux kernel 4.1 or later running on a 5th
Generation Intel Core processor or later.
The issue is documented as PR 19297.
When trying to enable branch tracing, in addition to checking the target
support for the requested branch tracing format, also check whether GDB
supports. it.
gdb/
* btrace.c (btrace_enable): Check whether HAVE_LIBIPT is defined.
testsuite/
* lib/gdb.exp (skip_btrace_pt_tests): Check for a "GDB does not
support" error.
Indicate speculatively executed instructions with a leading '?'. We use the
space that is normally used for the PC prefix. In the case where the
instruction at the current PC had been executed speculatively before, the PC
prefix will be partially overwritten resulting in "?> ".
As a side-effect, the /p modifier to omit the PC prefix in the "record
instruction-history" command now uses a 3-space PC prefix " " in order to
have enough space for the speculative execution indication.
gdb/
* btrace.c (btrace_compute_ftrace_bts): Clear insn flags.
(pt_btrace_insn_flags): New.
(ftrace_add_pt): Call pt_btrace_insn_flags.
* btrace.h (btrace_insn_flag): New.
(btrace_insn) <flags>: New.
* record-btrace.c (btrace_insn_history): Print insn prefix.
* NEWS: Announce it.
doc/
* gdb.texinfo (Process Record and Replay): Document prefixing of
speculatively executed instructions in the "record instruction-history"
command.
testsuite/
* gdb.btrace/instruction_history.exp: Update.
* gdb.btrace/tsx.exp: New.
* gdb.btrace/tsx.c: New.
* lib/gdb.exp (skip_tsx_tests, skip_btrace_pt_tests): New.
Fix the ARI warning about the use of unsigned long long. We can't use
ULONGEST as this is defined unsigned long on 64-bit systems. This will
result in a compile error when storing a pointer to an unsigned long long
structure field (declared in perf_event.h as __u64) in a ULONGEST * variable.
Use size_t to hold the buffer size inside GDB and __u64 when interfacing the
Linux kernel.
gdb/
* nat/linux-btrace.c (perf_event_read): Change the type of DATA_HEAD.
(perf_event_read_all): Change the type of SIZE and DATA_HEAD.
(perf_event_read_bts): Change the type of SIZE and READ.
(linux_enable_bts): Change the type of SIZE, PAGES, DATA_SIZE,
and DATA_OFFSET. Move DATA_SIZE declaration. Restrict the buffer size
to UINT_MAX. Check for overflows when using DATA_HEAD from the perf
mmap page.
(linux_enable_pt): Change the type of PAGES and SIZE. Restrict the
buffer size to UINT_MAX.
(linux_read_bts): Change the type of BUFFER_SIZE, SIZE, DATA_HEAD, and
DATA_TAIL.
* nat/linux-btrace.h (struct perf_event_buffer)<size, data_head>
<last_head>: Change type.
* common/btrace-common.h (struct btrace_dat_pt) <size>: Change type.
* common/btrace-common.c (btrace_data_append): Change the type of
SIZE.
* btrace.c (parse_xml_raw): Change the type of SIZE. Change oddness
check.
Add support for dumping new Intel(R) Processor Trace packets in the
"maint btrace packet-history" command.
gdb/
* btrace.c (pt_print_packet): Print stop, vmcs, tma, mtc, cyc, and
mnt packets.
When compiling GDB with 32-bit BFD, the build fails with:
In file included from btrace.h:33:0,
from btrace.c:23:
/usr/include/intel-pt.h:1643:51: note: expected 'int (*)(uint8_t *, size_t,
const struct pt_asid *, uint64_t, void *)' but argument is of type 'int
(*)(gdb_byte *, size_t, const struct pt_asid *, CORE_ADDR, void *)' extern
pt_export int pt_image_set_callback(struct pt_image *image, ^
gdb/
* btrace.c (btrace_pt_readmem_callback): Change type of PC argument.
Add maintenance commands that help debugging the btrace record target.
The following new commands are added:
maint info btrace
Print information about branch tracing internals.
maint btrace packet-history
Print the raw branch tracing data.
maint btrace clear-packet-history
Discard the stored raw branch tracing data.
maint btrace clear
Discard all branch tracing data. It will be fetched and processed
anew by the next "record" command.
maint set|show btrace pt skip-pad
Set and show whether PAD packets are skipped when computing the
packet history.
gdb/
* btrace.c: Include gdbcmd.h, cli/cli-utils.h, and ctype.h.
(maint_btrace_cmdlist, maint_btrace_set_cmdlist)
(maint_btrace_show_cmdlist, maint_btrace_pt_set_cmdlist)
(maint_btrace_pt_show_cmdlist, maint_btrace_pt_skip_pad)
(btrace_maint_clear): New.
(btrace_fetch, btrace_clear): Call btrace_maint_clear.
(pt_print_packet, btrace_maint_decode_pt)
(btrace_maint_update_pt_packets, btrace_maint_update_packets)
(btrace_maint_print_packets, get_uint, get_context_size, no_chunk)
(maint_btrace_packet_history_cmd)
(maint_btrace_clear_packet_history_cmd, maint_btrace_clear_cmd)
(maint_btrace_cmd, maint_btrace_set_cmd, maint_btrace_show_cmd)
(maint_btrace_pt_set_cmd, maint_btrace_pt_show_cmd)
(maint_info_btrace_cmd, _initialize_btrace): New.
* btrace.h (btrace_pt_packet, btrace_pt_packet_s)
(btrace_maint_packet_history, btrace_maint_info): New.
(btrace_thread_info) <maint>: New.
* NEWS: Announce it.
doc/
* gdb.texinfo (Maintenance Commands): Document "maint btrace"
commands.
Store the raw branch trace data that has been read from the target.
This data can be used for maintenance commands as well as for generating
a core file for the "record save" command.
gdb/
* btrace.c (btrace_fetch): Append the new trace data.
(btrace_clear): Clear the stored trace data.
* btrace.h (btrace_thread_info) <data>: New.
* common/btrace-common.h (btrace_data_clear)
(btrace_data_append): New.
* common/btrace-common.c (btrace_data_clear)
(btrace_data_append): New.
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.
This patch splits the TRY_CATCH macro into three, so that we go from
this:
~~~
volatile gdb_exception ex;
TRY_CATCH (ex, RETURN_MASK_ERROR)
{
}
if (ex.reason < 0)
{
}
~~~
to this:
~~~
TRY
{
}
CATCH (ex, RETURN_MASK_ERROR)
{
}
END_CATCH
~~~
Thus, we'll be getting rid of the local volatile exception object, and
declaring the caught exception in the catch block.
This allows reimplementing TRY/CATCH in terms of C++ exceptions when
building in C++ mode, while still allowing to build GDB in C mode
(using setjmp/longjmp), as a transition step.
TBC, after this patch, is it _not_ valid to have code between the TRY
and the CATCH blocks, like:
TRY
{
}
// some code here.
CATCH (ex, RETURN_MASK_ERROR)
{
}
END_CATCH
Just like it isn't valid to do that with C++'s native try/catch.
By switching to creating the exception object inside the CATCH block
scope, we can get rid of all the explicitly allocated volatile
exception objects all over the tree, and map the CATCH block more
directly to C++'s catch blocks.
The majority of the TRY_CATCH -> TRY+CATCH+END_CATCH conversion was
done with a script, rerun from scratch at every rebase, no manual
editing involved. After the mechanical conversion, a few places
needed manual intervention, to fix preexisting cases where we were
using the exception object outside of the TRY_CATCH block, and cases
where we were using "else" after a 'if (ex.reason) < 0)' [a CATCH
after this patch]. The result was folded into this patch so that GDB
still builds at each incremental step.
END_CATCH is necessary for two reasons:
First, because we name the exception object in the CATCH block, which
requires creating a scope, which in turn must be closed somewhere.
Declaring the exception variable in the initializer field of a for
block, like:
#define CATCH(EXCEPTION, mask) \
for (struct gdb_exception EXCEPTION; \
exceptions_state_mc_catch (&EXCEPTION, MASK); \
EXCEPTION = exception_none)
would avoid needing END_CATCH, but alas, in C mode, we build with C90,
which doesn't allow mixed declarations and code.
Second, because when TRY/CATCH are wired to real C++ try/catch, as
long as we need to handle cleanup chains, even if there's no CATCH
block that wants to catch the exception, we need for stop at every
frame in the unwind chain and run cleanups, then rethrow. That will
be done in END_CATCH.
After we require C++, we'll still need TRY/CATCH/END_CATCH until
cleanups are completely phased out -- TRY/CATCH in C++ mode will
save/restore the current cleanup chain, like in C mode, and END_CATCH
catches otherwise uncaugh exceptions, runs cleanups and rethrows, so
that C++ cleanups and exceptions can coexist.
IMO, this still makes the TRY/CATCH code look a bit more like a
newcomer would expect, so IMO worth it even if we weren't considering
C++.
gdb/ChangeLog.
2015-03-07 Pedro Alves <palves@redhat.com>
* common/common-exceptions.c (struct catcher) <exception>: No
longer a pointer to volatile exception. Now an exception value.
<mask>: Delete field.
(exceptions_state_mc_init): Remove all parameters. Adjust.
(exceptions_state_mc): No longer pop the catcher here.
(exceptions_state_mc_catch): New function.
(throw_exception): Adjust.
* common/common-exceptions.h (exceptions_state_mc_init): Remove
all parameters.
(exceptions_state_mc_catch): Declare.
(TRY_CATCH): Rename to ...
(TRY): ... this. Remove EXCEPTION and MASK parameters.
(CATCH, END_CATCH): New.
All callers adjusted.
gdb/gdbserver/ChangeLog:
2015-03-07 Pedro Alves <palves@redhat.com>
Adjust all callers of TRY_CATCH to use TRY/CATCH/END_CATCH
instead.
On some systems, _dl_runtime_resolve returns to the resolved function
instead of jumping to it. Since btrace will not find the function in
the current stack back trace, it will start a new back trace on the
same level. It will look the same to the user via the backtrace
command but the frames will have different id's which confuses stepping.
This fixes a test fail with 32-bit inferior reported by Jan Kratochvil.
gdb/
* btrace.c (ftrace_update_function): Treat return as tailcall for
"_dl_runtime_resolve".
The "record function-call-history" command prints the range of source lines
for a function segment when given the /l modifier. This information is
computed for the entire execution history when processing the recorded branch
trace.
To speed up the initial trace processing, we compute the information when
we print a function segment and only if requested. The computation is fast
enough (due to the limited scope) that it is not worth storing the data in
struct btrace_function, anymore.
gdb/
* btrace.h (btrace_function) <lbegin, lend>: Remove.
* btrace.c (ftrace_debug): Do not print the line range.
(ftrace_skip_file, ftrace_update_lines): Remove.
(ftrace_new_function): Remove lbegin and lend initialization.
(btrace_compute_ftrace_bts): Remove call to ftrace_update_lines.
* record-btrace.c (btrace_compute_src_line_range): New.
(btrace_call_history_src_line): Call btrace_compute_src_line_range.
Indicate gaps in the trace due to decode errors. Internally, a gap is
represented as a btrace function segment without instructions and with a
non-zero format-specific error code.
Show the gap when traversing the instruction or function call history.
Also indicate gaps in "info record".
It looks like this:
(gdb) info record
Active record target: record-btrace
Recording format: Branch Trace Store.
Buffer size: 64KB.
Recorded 32 instructions in 5 functions (1 gaps) for thread 1 (process 7182).
(gdb) record function-call-history /cli
1 fib inst 1,9 at src/fib.c:9,14
2 fib inst 10,20 at src/fib.c:6,14
3 [decode error (1): instruction overflow]
4 fib inst 21,28 at src/fib.c:11,14
5 fib inst 29,33 at src/fib.c:6,9
(gdb) record instruction-history 20,22
20 0x000000000040062f <fib+47>: sub $0x1,%rax
[decode error (1): instruction overflow]
21 0x0000000000400613 <fib+19>: add $0x1,%rax
22 0x0000000000400617 <fib+23>: mov %rax,0x200a3a(%rip)
(gdb)
Gaps are ignored during reverse execution and replay.
2015-02-09 Markus Metzger <markus.t.metzger@intel.com>
* btrace.c (ftrace_find_call): Skip gaps.
(ftrace_new_function): Initialize level.
(ftrace_new_call, ftrace_new_tailcall, ftrace_new_return)
(ftrace_new_switch): Update
level computation.
(ftrace_new_gap): New.
(ftrace_update_function): Create new function after gap.
(btrace_compute_ftrace_bts): Create gap on error.
(btrace_stitch_bts): Update parameters. Clear trace if it
becomes empty.
(btrace_stitch_trace): Update parameters. Update callers.
(btrace_clear): Reset the number of gaps.
(btrace_insn_get): Return NULL if the iterator points to a gap.
(btrace_insn_number): Return zero if the iterator points to a gap.
(btrace_insn_end): Allow gaps at the end.
(btrace_insn_next, btrace_insn_prev, btrace_insn_cmp): Handle gaps.
(btrace_find_insn_by_number): Assert that the found iterator does
not point to a gap.
(btrace_call_next, btrace_call_prev): Assert that the last function
is not a gap.
* btrace.h (btrace_bts_error): New.
(btrace_function): Update comment.
(btrace_function) <insn, insn_offset, number>: Update comment.
(btrace_function) <errcode>: New.
(btrace_thread_info) <ngaps>: New.
(btrace_thread_info) <replay>: Update comment.
(btrace_insn_get): Update comment.
* record-btrace.c (btrace_ui_out_decode_error): New.
(record_btrace_info): Print number of gaps.
(btrace_insn_history, btrace_call_history): Call
btrace_ui_out_decode_error for gaps.
(record_btrace_step_thread, record_btrace_start_replaying): Skip gaps.
testsuite/
* gdb.btrace/buffer-size.exp: Update "info record" output.
* gdb.btrace/delta.exp: Update "info record" output.
* gdb.btrace/enable.exp: Update "info record" output.
* gdb.btrace/finish.exp: Update "info record" output.
* gdb.btrace/instruction_history.exp: Update "info record" output.
* gdb.btrace/next.exp: Update "info record" output.
* gdb.btrace/nexti.exp: Update "info record" output.
* gdb.btrace/step.exp: Update "info record" output.
* gdb.btrace/stepi.exp: Update "info record" output.
* gdb.btrace/nohist.exp: Update "info record" output.
Add the instruction's size as well as a coarse classification to struct
btrace_insn. Use the information in ftrace_update_function and
ftrace_find_call.
2015-02-09 Markus Metzger <markus.t.metzger@intel.com>
* btrace.h (btrace_insn_class): New.
(btrace_insn) <size, iclass>: New.
* btrace.c (ftrace_find_call): Update parameters. Update users.
Use instruction classification.
(ftrace_new_return): Update parameters. Update users.
(ftrace_update_function): Update parameters. Update users. Use
instruction classification.
(ftrace_update_insns): Update parameters. Update users.
(ftrace_classify_insn): New.
(btrace_compute_ftrace_bts): Fill in new btrace_insn fields. Add
TRY_CATCH around call to gdb_insn_length.
Pass thread_info instead of btrace_thread_info to btrace_compute_ftrace.
We will need the thread_info in subsequent patches.
2015-02-09 Markus Metzger <markus.t.metzger@intel.com>
* btrace.c (btrace_compute_ftrace_bts, btrace_compute_ftrace):
Update parameters. Update users.
Allow the size of the branch trace ring buffer to be defined by the
user. The specified buffer size will be used when BTS tracing is
enabled for new threads.
The obtained buffer size may differ from the requested size. The
actual buffer size for the current thread is shown in the "info record"
command.
Bigger buffers mean longer traces, but also longer processing time.
2015-02-09 Markus Metzger <markus.t.metzger@intel.com>
* btrace.c (parse_xml_btrace_conf_bts): Add size.
(btrace_conf_bts_attributes): New.
(btrace_conf_children): Add attributes.
* common/btrace-common.h (btrace_config_bts): New.
(btrace_config)<bts>: New.
(btrace_config): Update comment.
* nat/linux-btrace.c (linux_enable_btrace, linux_enable_bts):
Use config.
* features/btrace-conf.dtd: Increment version. Add size
attribute to bts element.
* record-btrace.c (set_record_btrace_bts_cmdlist,
show_record_btrace_bts_cmdlist): New.
(record_btrace_adjust_size, record_btrace_print_bts_conf,
record_btrace_print_conf, cmd_set_record_btrace_bts,
cmd_show_record_btrace_bts): New.
(record_btrace_info): Call record_btrace_print_conf.
(_initialize_record_btrace): Add commands.
* remote.c: Add PACKET_Qbtrace_conf_bts_size enum.
(remote_protocol_features): Add Qbtrace-conf:bts:size packet.
(btrace_sync_conf): Synchronize bts size.
(_initialize_remote): Add Qbtrace-conf:bts:size packet.
* NEWS: Announce new commands and new packets.
doc/
* gdb.texinfo (Branch Trace Configuration Format): Add size.
(Process Record and Replay): Describe new set|show commands.
(General Query Packets): Describe Qbtrace-conf:bts:size packet.
testsuite/
* gdb.btrace/buffer-size: New.
gdbserver/
* linux-low.c (linux_low_btrace_conf): Print size.
* server.c (handle_btrace_conf_general_set): New.
(hanle_general_set): Call handle_btrace_conf_general_set.
(handle_query): Report Qbtrace-conf:bts:size as supported.
Add a struct to describe the branch trace configuration and use it for
enabling branch tracing.
The user will be able to set configuration fields for each tracing format
to be used for new threads.
The actual configuration that is active for a given thread will be shown
in the "info record" command.
At the moment, the configuration struct only contains a format field
that is set to the only available format.
The format is the only configuration option that can not be set via set
commands. It is given as argument to the "record btrace" command when
starting recording.
2015-02-09 Markus Metzger <markus.t.metzger@intel.com>
* Makefile.in (XMLFILES): Add btrace-conf.dtd.
* x86-linux-nat.c (x86_linux_enable_btrace): Update parameters.
(x86_linux_btrace_conf): New.
(x86_linux_create_target): Initialize to_btrace_conf.
* nat/linux-btrace.c (linux_enable_btrace): Update parameters.
Check format. Split into this and ...
(linux_enable_bts): ... this.
(linux_btrace_conf): New.
(perf_event_skip_record): Renamed into ...
(perf_event_skip_bts_record): ... this. Updated users.
(linux_disable_btrace): Split into this and ...
(linux_disable_bts): ... this.
(linux_read_btrace): Check format.
* nat/linux-btrace.h (linux_enable_btrace): Update parameters.
(linux_btrace_conf): New.
(btrace_target_info)<ptid>: Moved.
(btrace_target_info)<conf>: New.
(btrace_target_info): Split into this and ...
(btrace_tinfo_bts): ... this. Updated users.
* btrace.c (btrace_enable): Update parameters.
(btrace_conf, parse_xml_btrace_conf_bts, parse_xml_btrace_conf)
(btrace_conf_children, btrace_conf_attributes)
(btrace_conf_elements): New.
* btrace.h (btrace_enable): Update parameters.
(btrace_conf, parse_xml_btrace_conf): New.
* common/btrace-common.h (btrace_config): New.
* feature/btrace-conf.dtd: New.
* record-btrace.c (record_btrace_conf): New.
(record_btrace_cmdlist): New.
(record_btrace_enable_warn, record_btrace_open): Pass
&record_btrace_conf.
(record_btrace_info): Print recording format.
(cmd_record_btrace_bts_start): New.
(cmd_record_btrace_start): Call cmd_record_btrace_bts_start.
(_initialize_record_btrace): Add "record btrace bts" subcommand.
Add "record bts" alias command.
* remote.c (remote_state)<btrace_config>: New.
(remote_btrace_reset, PACKET_qXfer_btrace_conf): New.
(remote_protocol_features): Add qXfer:btrace-conf:read.
(remote_open_1): Call remote_btrace_reset.
(remote_xfer_partial): Handle TARGET_OBJECT_BTRACE_CONF.
(btrace_target_info)<conf>: New.
(btrace_sync_conf, btrace_read_config): New.
(remote_enable_btrace): Update parameters. Call btrace_sync_conf and
btrace_read_conf.
(remote_btrace_conf): New.
(init_remote_ops): Initialize to_btrace_conf.
(_initialize_remote): Add qXfer:btrace-conf packet.
* target.c (target_enable_btrace): Update parameters.
(target_btrace_conf): New.
* target.h (target_enable_btrace): Update parameters.
(target_btrace_conf): New.
(target_object)<TARGET_OBJECT_BTRACE_CONF>: New.
(target_ops)<to_enable_btrace>: Update parameters and comment.
(target_ops)<to_btrace_conf>: New.
* target-delegates: Regenerate.
* target-debug.h (target_debug_print_const_struct_btrace_config_p)
(target_debug_print_const_struct_btrace_target_info_p): New.
NEWS: Announce new command and new packet.
doc/
* gdb.texinfo (Process Record and Replay): Describe the "record
btrace bts" command.
(General Query Packets): Describe qXfer:btrace-conf:read packet.
(Branch Trace Configuration Format): New.
gdbserver/
* linux-low.c (linux_low_enable_btrace): Update parameters.
(linux_low_btrace_conf): New.
(linux_target_ops)<to_btrace_conf>: Initialize.
* server.c (current_btrace_conf): New.
(handle_btrace_enable): Rename to ...
(handle_btrace_enable_bts): ... this. Pass ¤t_btrace_conf
to target_enable_btrace. Update comment. Update users.
(handle_qxfer_btrace_conf): New.
(qxfer_packets): Add btrace-conf entry.
(handle_query): Report qXfer:btrace-conf:read as supported packet.
* target.h (target_ops)<enable_btrace>: Update parameters and comment.
(target_ops)<read_btrace_conf>: New.
(target_enable_btrace): Update parameters.
(target_read_btrace_conf): New.
testsuite/
* gdb.btrace/delta.exp: Update "info record" output.
* gdb.btrace/enable.exp: Update "info record" output.
* gdb.btrace/finish.exp: Update "info record" output.
* gdb.btrace/instruction_history.exp: Update "info record" output.
* gdb.btrace/next.exp: Update "info record" output.
* gdb.btrace/nexti.exp: Update "info record" output.
* gdb.btrace/step.exp: Update "info record" output.
* gdb.btrace/stepi.exp: Update "info record" output.
* gdb.btrace/nohist.exp: Update "info record" output.
Add a format argument to the various supports_btrace functions to check
for support of a specific btrace format. This is to prepare for a new
format.
Removed two redundant calls. The check will be made in the subsequent
btrace_enable call.
2015-02-09 Markus Metzger <markus.t.metzger@intel.com>
* btrace.c (btrace_enable): Pass BTRACE_FORMAT_BTS.
* record-btrace.c (record_btrace_open): Remove call to
target_supports_btrace.
* remote.c (remote_supports_btrace): Update parameters.
* target.c (target_supports_btrace): Update parameters.
* target.h (to_supports_btrace, target_supports_btrace): Update
parameters.
* target-delegates.c: Regenerate.
* target-debug.h (target_debug_print_enum_btrace_format): New.
* nat/linux-btrace.c
(kernel_supports_btrace): Rename into ...
(kernel_supports_bts): ... this. Update users. Update warning text.
(intel_supports_btrace): Rename into ...
(intel_supports_bts): ... this. Update users.
(cpu_supports_btrace): Rename into ...
(cpu_supports_bts): ... this. Update users.
(linux_supports_btrace): Update parameters. Split into this and ...
(linux_supports_bts): ... this.
* nat/linux-btrace.h (linux_supports_btrace): Update parameters.
gdbserver/
* server.c (handle_btrace_general_set): Remove call to
target_supports_btrace.
(supported_btrace_packets): New.
(handle_query): Call supported_btrace_packets.
* target.h: include btrace-common.h.
(btrace_target_info): Removed.
(supports_btrace, target_supports_btrace): Update parameters.
Add a structure to hold the branch trace data and an enum to describe
the format of that data. So far, only BTS is supported. Also added
a NONE format to indicate that no branch trace data is available.
This will make it easier to support different branch trace formats in
the future.
2015-02-09 Markus Metzger <markus.t.metzger@intel.com>
* Makefile.in (SFILES): Add common/btrace-common.c.
(COMMON_OBS): Add common/btrace-common.o.
(btrace-common.o): Add build rules.
* btrace.c (parse_xml_btrace): Update parameters.
(parse_xml_btrace_block): Set format field.
(btrace_add_pc, btrace_fetch): Use struct btrace_data.
(do_btrace_data_cleanup, make_cleanup_btrace_data): New.
(btrace_compute_ftrace): Split into this and...
(btrace_compute_ftrace_bts): ...this.
(btrace_stitch_trace): Split into this and...
(btrace_stitch_bts): ...this.
* btrace.h (parse_xml_btrace): Update parameters.
(make_cleanup_btrace_data): New.
* common/btrace-common.c: New.
* common/btrace-common.h: Include common-defs.h.
(btrace_block_s): Update comment.
(btrace_format): New.
(btrace_format_string): New.
(btrace_data_bts): New.
(btrace_data): New.
(btrace_data_init, btrace_data_fini, btrace_data_empty): New.
* remote.c (remote_read_btrace): Update parameters.
* target.c (target_read_btrace): Update parameters.
* target.h (target_read_btrace): Update parameters.
(target_ops)<to_read_btrace>: Update parameters.
* x86-linux-nat.c (x86_linux_read_btrace): Update parameters.
* target-delegates.c: Regenerate.
* target-debug (target_debug_print_struct_btrace_data_p): New.
* nat/linux-btrace.c (linux_read_btrace): Split into this and...
(linux_read_bts): ...this.
* nat/linux-btrace.h (linux_read_btrace): Update parameters.
gdbserver/
* Makefile.in (SFILES): Add common/btrace-common.c.
(OBS): Add common/btrace-common.o.
(btrace-common.o): Add build rules.
* linux-low: Include btrace-common.h.
(linux_low_read_btrace): Use struct btrace_data. Call
btrace_data_init and btrace_data_fini.
This commit makes all source files under gdb/ that include headers
from gdb/ include either defs.h or server.h before any other code.
This ensures that definitions and macros from the two config.h files
are always in place for our code. An exception has been made for
gdb/gdbserver/gdbreplay.c which seems to be a special case.
gdb/
2014-07-30 Gary Benson <gbenson@redhat.com>
* btrace.c: Include defs.h.
* common/ptid.c: Include defs.h or server.h as appropriate.
* nat/mips-linux-watch.c: Likewise.
gdb/gdbserver/
2014-07-30 Gary Benson <gbenson@redhat.com>
* hostio-errno.c: Move server.h to top of includes list.
* inferiors.c: Likewise.
* linux-x86-low.c: Likewise.
* notif.c: Include server.h.
Running gdb.threads/thread-execl.exp with scheduler-locking set to
"step" reveals a problem:
(gdb) next^M
[Thread 0x7ffff7fda700 (LWP 27168) exited]^M
[New LWP 27168]^M
[Thread 0x7ffff74ee700 (LWP 27174) exited]^M
process 27168 is executing new program: /home/jkratoch/redhat/gdb-clean/gdb/testsuite/gdb.threads/thread-execl^M
[Thread debugging using libthread_db enabled]^M
Using host libthread_db library "/lib64/libthread_db.so.1".^M
infrun.c:5225: internal-error: switch_back_to_stepped_thread: Assertion `!schedlock_applies (1)' failed.^M
A problem internal to GDB has been detected,^M
further debugging may prove unreliable.^M
Quit this debugging session? (y or n) FAIL: gdb.threads/thread-execl.exp: schedlock step: get to main in new image (GDB internal error)
The assertion is correct. The issue is that GDB is mistakenly trying
to switch back to an exited thread, that was previously stepping when
it exited. This is exactly the sort of thing the test wants to make
sure doesn't happen:
# Now set a breakpoint at `main', and step over the execl call. The
# breakpoint at main should be reached. GDB should not try to revert
# back to the old thread from the old image and resume stepping it
We don't see this bug with schedlock off only because a different
sequence of events makes GDB manage to delete the thread instead of
marking it exited.
This particular internal error can be fixed by making the loop over
all threads in switch_back_to_stepped_thread skip exited threads.
But, looking over other ALL_THREADS users, all either can or should be
skipping exited threads too. So for simplicity, this patch replaces
ALL_THREADS with a new macro that skips exited threads itself, and
updates everything to use it.
Tested on x86_64 Fedora 20.
gdb/
2014-06-19 Pedro Alves <palves@redhat.com>
* gdbthread.h (ALL_THREADS): Delete.
(ALL_NON_EXITED_THREADS): New macro.
* btrace.c (btrace_free_objfile): Use ALL_NON_EXITED_THREADS
instead of ALL_THREADS.
* infrun.c (find_thread_needs_step_over)
(switch_back_to_stepped_thread): Use ALL_NON_EXITED_THREADS
instead of ALL_THREADS.
* record-btrace.c (record_btrace_open)
(record_btrace_stop_recording, record_btrace_close)
(record_btrace_is_replaying, record_btrace_resume)
(record_btrace_find_thread_to_move, record_btrace_wait): Likewise.
* remote.c (append_pending_thread_resumptions): Likewise.
* thread.c (thread_apply_all_command): Likewise.
gdb/testsuite/
2014-06-19 Pedro Alves <palves@redhat.com>
* gdb.threads/thread-execl.exp (do_test): New procedure, factored
out from ...
(top level): ... here. Iterate running tests under different
scheduler-locking settings.
The btrace record target shows the branch trace from the location of the first
branch destination. This is the first BTS records.
After adding incremental updates, we can now add a dummy record for the current
PC when we enable tracing so we show the trace from the location where branch
tracing has been enabled.
2014-01-16 Markus Metzger <markus.t.metzger@intel.com>
* btrace.c: Include regcache.h.
(btrace_add_pc): New.
(btrace_enable): Call btrace_add_pc.
(btrace_is_empty): New.
* btrace.h (btrace_is_empty): New.
* record-btrace.c (require_btrace, record_btrace_info): Call
btrace_is_empty.
testsuite/
* gdb.btrace/Makefile.in (EXECUTABLES): Add delta.
* gdb.btrace/exception.exp: Update.
* gdb.btrace/instruction_history.exp: Update.
* gdb.btrace/record_goto.exp: Update.
* gdb.btrace/tailcall.exp: Update.
* gdb.btrace/unknown_functions.exp: Update.
* gdb.btrace/delta.exp: New.
Read branch trace data incrementally and extend the current trace rather than
discarding it and reading the entire trace buffer each time.
If the branch trace buffer overflowed, we can't extend the current trace so we
discard it and start anew by reading the entire branch trace buffer.
2014-01-16 Markus Metzger <markus.t.metzger@intel.com>
* common/linux-btrace.c (perf_event_read_bts, linux_read_btrace):
Support delta reads.
(linux_disable_btrace): Change return type.
* common/linux-btrace.h (linux_read_btrace): Change parameters
and return type to allow error reporting. Update users.
(linux_disable_btrace): Change return type. Update users.
* common/btrace-common.h (btrace_read_type) <BTRACE_READ_DELTA>:
New.
(btrace_error): New.
(btrace_block) <begin>: Comment on BEGIN == 0.
* btrace.c (btrace_compute_ftrace): Start from the end of
the current trace.
(btrace_stitch_trace, btrace_clear_history): New.
(btrace_fetch): Read delta trace, return if replaying.
(btrace_clear): Move clear history code to btrace_clear_history.
(parse_xml_btrace): Throw an error if parsing failed.
* target.h (struct target_ops) <to_read_btrace>: Change parameters
and return type to allow error reporting.
(target_read_btrace): Change parameters and return type to allow
error reporting.
* target.c (target_read_btrace): Update.
* remote.c (remote_read_btrace): Support delta reads. Pass
errors on.
* NEWS: Announce it.
gdbserver/
* target.h (target_ops) <read_btrace>: Change parameters and
return type to allow error reporting.
* server.c (handle_qxfer_btrace): Support delta reads. Pass
trace reading errors on.
* linux-low.c (linux_low_read_btrace): Pass trace reading
errors on.
(linux_low_disable_btrace): New.
Extend the always failing unwinder to provide the PC based on the call
structure detected in the branch trace.
The unwinder supports normal frames and tailcall frames.
Inline frames are not supported.
2014-01-16 Markus Metzger <markus.t.metzger@intel.com>
* record.h (record_btrace_frame_unwind)
(record_btrace_tailcall_frame_unwind): New declarations.
* dwarf2-frame: Include record.h
(dwarf2_frame_cfa): Throw an error for btrace frames.
* record-btrace.c: Include hashtab.h.
(btrace_get_bfun_name): New.
(btrace_call_history): Call btrace_get_bfun_name.
(struct btrace_frame_cache): New.
(bfcache): New.
(bfcache_hash, bfcache_eq, bfcache_new): New.
(btrace_get_frame_function): New.
(record_btrace_frame_unwind_stop_reason): Allow unwinding.
(record_btrace_frame_this_id): Compute own id.
(record_btrace_frame_prev_register): Provide PC, throw_error
for all other registers.
(record_btrace_frame_sniffer): Detect btrace frames.
(record_btrace_tailcall_frame_sniffer): New.
(record_btrace_frame_dealloc_cache): New.
(record_btrace_frame_unwind): Add new functions.
(record_btrace_tailcall_frame_unwind): New.
(_initialize_record_btrace): Allocate cache.
* btrace.c (btrace_clear): Call reinit_frame_cache.
* NEWS: Announce it.
testsuite/
* gdb.btrace/record_goto.exp: Add backtrace test.
* gdb.btrace/tailcall.exp: Add backtrace test.
Add a branch trace instruction iterator pointing to the current replay position
to the branch trace thread info struct.
Free the iterator when btrace is cleared.
Start at the replay position for the instruction and function-call histories.
2014-01-16 Markus Metzger <markus.t.metzger@intel.com>
* btrace.h (replay) <replay>: New.
(btrace_is_replaying): New.
* btrace.c (btrace_clear): Free replay iterator.
(btrace_is_replaying): New.
* record-btrace.c (record_btrace_is_replaying): New.
(record_btrace_info): Print insn number if replaying.
(record_btrace_insn_history): Start at replay position.
(record_btrace_call_history): Start at replay position.
(init_record_btrace_ops): Init to_record_is_replaying.
Add a new modifier /c to the "record function-call-history" command to
indent the function name based on its depth in the call stack.
Also reorder the optional fields to have the indentation at the very beginning.
Prefix the insn range (/i modifier) with "inst ".
Prefix the source line (/l modifier) with "at ".
Change the range syntax from "begin-end" to "begin,end" to allow copy&paste to
the "record instruction-history" and "list" commands.
Adjust the respective tests and add new tests for the /c modifier.
2014-01-16 Markus Metzger <markus.t.metzger@intel.com>
* record.h (enum record_print_flag)
<record_print_indent_calls>: New.
* record.c (get_call_history_modifiers): Recognize /c modifier.
(_initialize_record): Document /c modifier.
* record-btrace.c (btrace_call_history): Add btinfo parameter.
Reorder fields. Optionally indent the function name. Update
all users.
* NEWS: Announce changes.
testsuite/
* gdb.btrace/function_call_history.exp: Fix expected field
order for "record function-call-history".
Add new tests for "record function-call-history /c".
* gdb.btrace/exception.cc: New.
* gdb.btrace/exception.exp: New.
* gdb.btrace/tailcall.exp: New.
* gdb.btrace/x86-tailcall.S: New.
* gdb.btrace/x86-tailcall.c: New.
* gdb.btrace/unknown_functions.c: New.
* gdb.btrace/unknown_functions.exp: New.
* gdb.btrace/Makefile.in (EXECUTABLES): Add new.
doc/
* gdb.texinfo (Process Record and Replay): Document new /c
modifier accepted by "record function-call-history".
Add /i modifier to "record function-call-history" example.
The record instruction-history and record-function-call-history commands start
counting instructions at zero. This is somewhat unintuitive when we start
navigating in the recorded instruction history. Start at one, instead.
2014-01-16 Markus Metzger <markus.t.metzger@intel.com>
* btrace.c (ftrace_new_function): Start counting at one.
* record-btrace.c (record_btrace_info): Adjust number of calls
and insns.
* NEWS: Announce it.
testsuite/
* gdb.btrace/instruction_history.exp: Update.
* gdb.btrace/function_call_history.exp: Update.
The branch trace is represented as 3 vectors:
- a block vector
- a instruction vector
- a function vector
Each vector (except for the first) is computed from the one above.
Change this into a graph where a node represents a sequence of instructions
belonging to the same function and where we have three types of edges to connect
the function segments:
- control flow
- same function (instance)
- call stack
This allows us to navigate in the branch trace. We will need this for "record
goto" and reverse execution.
This patch introduces the data structure and computes the control flow edges.
It also introduces iterator structs to simplify iterating over the branch trace
in control-flow order.
It also fixes PR gdb/15240 since now recursive calls are handled correctly.
Fix the test that got the number of expected fib instances and also the
function numbers wrong.
The current instruction had been part of the branch trace. This will look odd
once we start support for reverse execution. Remove it. We still keep it in
the trace itself to allow extending the branch trace more easily in the future.
2014-01-16 Markus Metzger <markus.t.metzger@intel.com>
* btrace.h (struct btrace_func_link): New.
(enum btrace_function_flag): New.
(struct btrace_inst): Rename to ...
(struct btrace_insn): ...this. Update all users.
(struct btrace_func) <ibegin, iend>: Remove.
(struct btrace_func_link): New.
(struct btrace_func): Rename to ...
(struct btrace_function): ...this. Update all users.
(struct btrace_function) <segment, flow, up, insn, insn_offset)
(number, level, flags>: New.
(struct btrace_insn_iterator): Rename to ...
(struct btrace_insn_history): ...this.
Update all users.
(struct btrace_insn_iterator, btrace_call_iterator): New.
(struct btrace_target_info) <btrace, itrace, ftrace>: Remove.
(struct btrace_target_info) <begin, end, level>
<insn_history, call_history>: New.
(btrace_insn_get, btrace_insn_number, btrace_insn_begin)
(btrace_insn_end, btrace_insn_prev, btrace_insn_next)
(btrace_insn_cmp, btrace_find_insn_by_number, btrace_call_get)
(btrace_call_number, btrace_call_begin, btrace_call_end)
(btrace_call_prev, btrace_call_next, btrace_call_cmp)
(btrace_find_function_by_number, btrace_set_insn_history)
(btrace_set_call_history): New.
* btrace.c (btrace_init_insn_iterator)
(btrace_init_func_iterator, compute_itrace): Remove.
(ftrace_print_function_name, ftrace_print_filename)
(ftrace_skip_file): Change
parameter to const.
(ftrace_init_func): Remove.
(ftrace_debug): Use new btrace_function fields.
(ftrace_function_switched): Also consider gaining and
losing symbol information).
(ftrace_print_insn_addr, ftrace_new_call, ftrace_new_return)
(ftrace_new_switch, ftrace_find_caller, ftrace_new_function)
(ftrace_update_caller, ftrace_fixup_caller, ftrace_new_tailcall):
New.
(ftrace_new_function): Move. Remove debug print.
(ftrace_update_lines, ftrace_update_insns): New.
(ftrace_update_function): Check for call, ret, and jump.
(compute_ftrace): Renamed to ...
(btrace_compute_ftrace): ...this. Rewritten to compute call
stack.
(btrace_fetch, btrace_clear): Updated.
(btrace_insn_get, btrace_insn_number, btrace_insn_begin)
(btrace_insn_end, btrace_insn_prev, btrace_insn_next)
(btrace_insn_cmp, btrace_find_insn_by_number, btrace_call_get)
(btrace_call_number, btrace_call_begin, btrace_call_end)
(btrace_call_prev, btrace_call_next, btrace_call_cmp)
(btrace_find_function_by_number, btrace_set_insn_history)
(btrace_set_call_history): New.
* record-btrace.c (require_btrace): Use new btrace thread
info fields.
(record_btrace_info, btrace_insn_history)
(record_btrace_insn_history, record_btrace_insn_history_range):
Use new btrace thread info fields and new iterator.
(btrace_func_history_src_line): Rename to ...
(btrace_call_history_src_line): ...this. Use new btrace
thread info fields.
(btrace_func_history): Rename to ...
(btrace_call_history): ...this. Use new btrace thread info
fields and new iterator.
(record_btrace_call_history, record_btrace_call_history_range):
Use new btrace thread info fields and new iterator.
testsuite/
* gdb.btrace/function_call_history.exp: Fix expected function
trace.
* gdb.btrace/instruction_history.exp: Initialize traced.
Remove traced_functions.
Add a function to parse a btrace xml document into a vector of branch trace
blocks.
gdb/
* features/btrace.dtd: New file.
* Makefile.in (XMLFILES): Add btrace.dtd.
* btrace.h (parse_xml_btrace): New declaration.
* btrace.c: Include xml-support.h.
(parse_xml_btrace): New function.
(parse_xml_btrace_block): New function.
(block_attributes): New struct.
(btrace_attributes): New struct.
(btrace_children): New struct.
(btrace_elements): New struct.
Markus Metzger