When I run no-thread-db.exp, the breakpoint is set on line 26.
However, the breakpoint is set to line 26 of dl-start.S rather than
no-thread-db.c, which is not intended.
(gdb) monitor set libthread-db-search-path /foo/bar^M
libthread-db-search-path set to `/foo/bar'^M
(gdb) PASS: gdb.server/no-thread-db.exp: libthread-db is now unresolvable
break 26^M
Breakpoint 1 at 0x48018078: file ../sysdeps/powerpc/powerpc32/dl-start.S, line 26.^M
(gdb) continue^M
Continuing.
This patch is to change the breakpoint setting with source file
specified, then it is correct now.
gdb/testsuite:
2014-05-26 Yao Qi <yao@codesourcery.com>
* gdb.server/no-thread-db.exp: Specify source file name
explicitly when setting a breakpoint.
gdb/doc/guile.texi (Types In Guile, Basic Guile, Frames In Guile)
(Breakpoints In Guile, Guile Printing Module)
(Guile Exception Handling, Values From Inferior In Guile)
(Objfiles In Guile, Breakpoints In Guile, Memory Ports in Guile):
Don't use @var at the beginning of a sentence.
gdb/doc/gdb.texinfo (Frame Filter Management, Trace Files)
(C Operators, Ada Tasks, Calling, Bootstrapping, ARM)
(PowerPC Embedded, Define, Annotations for Running)
(IPA Protocol Commands, Packets, General Query Packets)
(Tracepoint Packets, Notification Packets, Environment)
(Inferiors and Programs, Set Breaks, Set Catchpoints)
(Continuing and Stepping, Signals, Thread-Specific Breakpoints)
(Frames, Backtrace, Selection, Expressions, Registers)
(Trace State Variables, Built-In Func/Proc, Signaling, Files)
(Numbers, GDB/MI Async Records, GDB/MI Data Manipulation)
(Source Annotations, Using JIT Debug Info Readers, Packets)
(Stop Reply Packets, Host I/O Packets)
(Target Description Format): Don't use @var at the beginning of a
sentence.
gdb/doc/python.texi (Basic Python, Types In Python)
(Commands In Python, Frames In Python, Line Tables In Python)
(Breakpoints In Python, gdb.printing, gdb.types)
(Type Printing API): Don't use @var at the beginning of a
sentence.
A recent change to glibc removed asm/ptrace.h from user.h for AArch64.
This meant that cross-native builds of gdbserver using trunk glibc broke
because linux-aarch64-low.c because user_hwdebug_state couldn't be found.
This is like commit #036cd38182bde32d8297b630cd5c861d53b8949e
2014-05-23 Ramana Radhakrishnan <ramana.radhakrishnan@arm.com>
* linux-aarch64-low.c (asm/ptrace.h): Include.
When loading symbols for the vdso, also add its sections to target_sections.
This fixes an issue with record btrace where vdso instructions could not be
disassembled during replay.
* symfile-mem.c (symbol_file_add_from_memory): Add BFD sections.
testsuite/
* gdb.btrace/vdso.c: New.
* gdb.btrace/vdso.exp: New.
Allow gcore's capture_command_output function to be used by other tests.
testsuite/
* gdb.base/gcore.exp (capture_command_output): Move ...
* lib/gdb.exp (capture_command_output): ... here.
The btrace record target does not trace data. We therefore do not allow
accessing read-write memory during replay.
In some cases, this might be useful to advanced users, though, who we assume
to know what they are doing.
Add a set|show command pair to turn this memory access restriction off.
* record-btrace.c (record_btrace_allow_memory_access): Remove.
(replay_memory_access_read_only, replay_memory_access_read_write)
(replay_memory_access_types, replay_memory_access)
(set_record_btrace_cmdlist, show_record_btrace_cmdlist)
(cmd_set_record_btrace, cmd_show_record_btrace)
(cmd_show_replay_memory_access): New.
(record_btrace_xfer_partial, record_btrace_insert_breakpoint)
(record_btrace_remove_breakpoint): Replace
record_btrace_allow_memory_access with replay_memory_access.
(_initialize_record_btrace): Add commands.
* NEWS: Announce it.
testsuite/
* gdb.btrace/data.exp: Test it.
doc/
* gdb.texinfo (Process Record and Replay): Document it.
It should clear up confusion about the args parameter to mi_run_cmd_full.
Thanks to Joel for clear formulation. I also added a comment about the
impact of use_gdb_stub.
gdb/testsuite/ChangeLog:
2014-05-22 Simon Marchi <simon.marchi@ericsson.com>
* lib/mi-support.exp (mi_run_cmd_full): Add comments.
A recent change to glibc removed asm/ptrace.h from user.h for
AArch64. This meant that cross-native builds of gdb using trunk
glibc broke because aarch64-linux-nat.c because user_hwdebug_state
couldn't be found.
Fixed by including asm/ptrace.h like other ports.
2014-05-22 Ramana Radhakrishnan <ramana.radhakrishnan@arm.com>
* aarch64-linux-nat.c (asm/ptrace.h): Include.
Move infrun.c declarations out of inferior.h to a new infrun.h file.
Tested by building on:
i686-w64-mingw32, enable-targets=all
x86_64-linux, enable-targets=all
i586-pc-msdosdjgpp
And also grepped the whole tree for each symbol moved to find where
infrun.h might be necessary.
gdb/
2014-05-22 Pedro Alves <palves@redhat.com>
* inferior.h (debug_infrun, debug_displaced, stop_on_solib_events)
(sync_execution, sched_multi, step_stop_if_no_debug, non_stop)
(disable_randomization, enum exec_direction_kind)
(execution_direction, stop_registers, start_remote)
(clear_proceed_status, proceed, resume, user_visible_resume_ptid)
(wait_for_inferior, normal_stop, get_last_target_status)
(prepare_for_detach, fetch_inferior_event, init_wait_for_inferior)
(insert_step_resume_breakpoint_at_sal)
(follow_inferior_reset_breakpoints, stepping_past_instruction_at)
(set_step_info, print_stop_event, signal_stop_state)
(signal_print_state, signal_pass_state, signal_stop_update)
(signal_print_update, signal_pass_update)
(update_signals_program_target, clear_exit_convenience_vars)
(displaced_step_dump_bytes, update_observer_mode)
(signal_catch_update, gdb_signal_from_command): Move
declarations ...
* infrun.h: ... to this new file.
* amd64-tdep.c: Include infrun.h.
* annotate.c: Include infrun.h.
* arch-utils.c: Include infrun.h.
* arm-linux-tdep.c: Include infrun.h.
* arm-tdep.c: Include infrun.h.
* break-catch-sig.c: Include infrun.h.
* breakpoint.c: Include infrun.h.
* common/agent.c: Include infrun.h instead of inferior.h.
* corelow.c: Include infrun.h.
* event-top.c: Include infrun.h.
* go32-nat.c: Include infrun.h.
* i386-tdep.c: Include infrun.h.
* inf-loop.c: Include infrun.h.
* infcall.c: Include infrun.h.
* infcmd.c: Include infrun.h.
* infrun.c: Include infrun.h.
* linux-fork.c: Include infrun.h.
* linux-nat.c: Include infrun.h.
* linux-thread-db.c: Include infrun.h.
* monitor.c: Include infrun.h.
* nto-tdep.c: Include infrun.h.
* procfs.c: Include infrun.h.
* record-btrace.c: Include infrun.h.
* record-full.c: Include infrun.h.
* remote-m32r-sdi.c: Include infrun.h.
* remote-mips.c: Include infrun.h.
* remote-notif.c: Include infrun.h.
* remote-sim.c: Include infrun.h.
* remote.c: Include infrun.h.
* reverse.c: Include infrun.h.
* rs6000-tdep.c: Include infrun.h.
* s390-linux-tdep.c: Include infrun.h.
* solib-irix.c: Include infrun.h.
* solib-osf.c: Include infrun.h.
* solib-svr4.c: Include infrun.h.
* target.c: Include infrun.h.
* top.c: Include infrun.h.
* windows-nat.c: Include infrun.h.
* mi/mi-interp.c: Include infrun.h.
* mi/mi-main.c: Include infrun.h.
* python/py-threadevent.c: Include infrun.h.
A small cleanup - so we can call the print routine without affecting
--return-child-result.
gdb/
2014-05-22 Pedro Alves <palves@redhat.com>
* infrun.c (handle_inferior_event): Store the exit code for
--return-child-result here, instead of ...
(print_exited_reason): ... here.
The other part of PR gdb/13860 is about console execution commands in
MI getting their output half lost. E.g., take the finish command,
executed on a frontend's GDB console:
sync:
finish
&"finish\n"
~"Run till exit from #0 usleep (useconds=10) at ../sysdeps/unix/sysv/linux/usleep.c:27\n"
^running
*running,thread-id="1"
(gdb)
~"0x00000000004004d7 in foo () at stepinf.c:6\n"
~"6\t usleep (10);\n"
~"Value returned is $1 = 0\n"
*stopped,reason="function-finished",frame={addr="0x00000000004004d7",func="foo",args=[],file="stepinf.c",fullname="/home/pedro/gdb/tests/stepinf.c",line="6"},thread-id="1",stopped-threads="all",core="1"
async:
finish
&"finish\n"
~"Run till exit from #0 usleep (useconds=10) at ../sysdeps/unix/sysv/linux/usleep.c:27\n"
^running
*running,thread-id="1"
(gdb)
*stopped,reason="function-finished",frame={addr="0x00000000004004d7",func="foo",args=[],file="stepinf.c",fullname="/home/pedro/gdb/tests/stepinf.c",line="6"},gdb-result-var="$1",return-value="0",thread-id="1",stopped-threads="all",core="0"
Note how all the "Value returned" etc. output is missing in async mode.
The same happens with e.g., catchpoints:
=breakpoint-modified,bkpt={number="1",type="catchpoint",disp="keep",enabled="y",what="22016",times="1"}
~"\nCatchpoint "
~"1 (forked process 22016), 0x0000003791cbd8a6 in __libc_fork () at ../nptl/sysdeps/unix/sysv/linux/fork.c:131\n"
~"131\t pid = ARCH_FORK ();\n"
*stopped,reason="fork",disp="keep",bkptno="1",newpid="22016",frame={addr="0x0000003791cbd8a6",func="__libc_fork",args=[],file="../nptl/sysdeps/unix/sysv/linux/fork.c",fullname="/usr/src/debug/glibc-2.14-394-g8f3b1ff/nptl/sysdeps/unix/sysv/linux/fork.c",line="131"},thread-id="1",stopped-threads="all",core="0"
where all those ~ lines are missing in async mode, or just the "step"
current line indication:
s
&"s\n"
^running
*running,thread-id="all"
(gdb)
~"13\t foo ();\n"
*stopped,frame={addr="0x00000000004004ef",func="main",args=[{name="argc",value="1"},{name="argv",value="0x7fffffffdd78"}],file="stepinf.c",fullname="/home/pedro/gdb/tests/stepinf.c",line="13"},thread-id="1",stopped-threads="all",core="3"
(gdb)
Or in the case of the PRs example, the "Stopped due to shared library
event" note:
start
&"start\n"
~"Temporary breakpoint 1 at 0x400608: file ../../../src/gdb/testsuite/gdb.mi/solib-main.c, line 21.\n"
=breakpoint-created,bkpt={number="1",type="breakpoint",disp="del",enabled="y",addr="0x0000000000400608",func="main",file="../../../src/gdb/testsuite/gdb.mi/solib-main.c",fullname="/home/pedro/gdb/mygit/src/gdb/testsuite/gdb.mi/solib-main.c",line="21",times="0",original-location="main"}
~"Starting program: /home/pedro/gdb/mygit/build/gdb/testsuite/gdb.mi/solib-main \n"
=thread-group-started,id="i1",pid="21990"
=thread-created,id="1",group-id="i1"
^running
*running,thread-id="all"
(gdb)
=library-loaded,id="/lib64/ld-linux-x86-64.so.2",target-name="/lib64/ld-linux-x86-64.so.2",host-name="/lib64/ld-linux-x86-64.so.2",symbols-loaded="0",thread-group="i1"
~"Stopped due to shared library event (no libraries added or removed)\n"
*stopped,reason="solib-event",thread-id="1",stopped-threads="all",core="3"
(gdb)
IMO, if you're typing execution commands in a frontend's console, you
expect to see their output. Indeed it's what you get in sync mode. I
think async mode should do the same. Deciding what to mirror to the
console wrt to breakpoints and random stops gets messy real fast.
E.g., say "s" trips on a breakpoint. We'd clearly want to mirror the
event to the console in this case. But what about more complicated
cases like "s&; thread n; s&", and one of those steps spawning a new
thread, and that thread hitting a breakpoint? It's impossible in
general to track whether the thread had any relation to the commands
that had been executed. So I think we should just simplify and always
mirror breakpoints and random events to the console.
Notes:
- mi->out is the same as gdb_stdout when MI is the current
interpreter. I think that referring to that directly is cleaner.
An earlier revision of this patch made the changes that are now
done in mi_on_normal_stop directly in infrun.c:normal_stop, and so
not having an obvious place to put the new uiout by then, and not
wanting to abuse CLI's uiout, I made a temporary uiout when
necessary.
- Hopefuly the rest of the patch is more or less obvious given the
comments added.
Tested on x86_64 Fedora 20, no regressions.
2014-05-21 Pedro Alves <palves@redhat.com>
PR gdb/13860
* gdbthread.h (struct thread_control_state): New field
`command_interp'.
* infrun.c (follow_fork): Copy the new thread control field to the
child fork thread.
(clear_proceed_status_thread): Clear the new thread control field.
(proceed): Set the new thread control field.
* interps.h (command_interp): Declare.
* interps.c (command_interpreter): New global.
(command_interp): New function.
(interp_exec): Set `command_interpreter' while here.
* cli-out.c (cli_uiout_dtor): New function.
(cli_ui_out_impl): Install it.
* mi/mi-interp.c: Include cli-out.h.
(mi_cmd_interpreter_exec): Add comment.
(restore_current_uiout_cleanup): New function.
(ui_out_free_cleanup): New function.
(mi_on_normal_stop): If finishing an execution command started by
a CLI command, or any kind of breakpoint-like event triggered,
print the stop event to the output (CLI) stream.
* mi/mi-out.c (mi_ui_out_impl): Install NULL `dtor' handler.
2014-05-21 Pedro Alves <palves@redhat.com>
PR gdb/13860
* gdb.mi/mi-cli.exp (line_callee4_next_step): New global.
(top level): Test that output related to execution commands is
sent to the console with CLI commands, but not with MI commands.
Test that breakpoint events are always mirrored to the console.
Also expect the new source line to be output after a "next" in
async mode too. Make it a pass/fail test.
* gdb.mi/mi-solib.exp: Test that the CLI solib event note is
output.
* lib/mi-support.exp (mi_gdb_expect_cli_output): New procedure.
I noticed that "list" behaves differently in CLI vs MI. Particularly:
$ ./gdb -nx -q ./testsuite/gdb.mi/mi-cli
Reading symbols from /home/pedro/gdb/mygit/build/gdb/testsuite/gdb.mi/mi-cli...done.
(gdb) start
Temporary breakpoint 1 at 0x40054d: file ../../../src/gdb/testsuite/gdb.mi/basics.c, line 62.
Starting program: /home/pedro/gdb/mygit/build/gdb/testsuite/gdb.mi/mi-cli
Temporary breakpoint 1, main () at ../../../src/gdb/testsuite/gdb.mi/basics.c:62
62 callee1 (2, "A string argument.", 3.5);
(gdb) list
57 {
58 }
59
60 main ()
61 {
62 callee1 (2, "A string argument.", 3.5);
63 callee1 (2, "A string argument.", 3.5);
64
65 do_nothing (); /* Hello, World! */
66
(gdb)
Note the list started at line 57. IOW, the program stopped at line
62, and GDB centered the list on that.
compare with:
$ ./gdb -nx -q ./testsuite/gdb.mi/mi-cli -i=mi
=thread-group-added,id="i1"
~"Reading symbols from /home/pedro/gdb/mygit/build/gdb/testsuite/gdb.mi/mi-cli..."
~"done.\n"
(gdb)
start
&"start\n"
...
~"\nTemporary breakpoint "
~"1, main () at ../../../src/gdb/testsuite/gdb.mi/basics.c:62\n"
~"62\t callee1 (2, \"A string argument.\", 3.5);\n"
*stopped,reason="breakpoint-hit",disp="del",bkptno="1",frame={addr="0x000000000040054d",func="main",args=[],file="../../../src/gdb/testsuite/gdb.mi/basics.c",fullname="/home/pedro/gdb/mygit/src/gdb/testsuite/gdb.mi/basics.c",line="62"},thread-id="1",stopped-threads="all",core="0"
=breakpoint-deleted,id="1"
(gdb)
-interpreter-exec console list
~"62\t callee1 (2, \"A string argument.\", 3.5);\n"
~"63\t callee1 (2, \"A string argument.\", 3.5);\n"
~"64\t\n"
~"65\t do_nothing (); /* Hello, World! */\n"
~"66\t\n"
~"67\t callme (1);\n"
~"68\t callme (2);\n"
~"69\t\n"
~"70\t return 0;\n"
~"71\t}\n"
^done
(gdb)
Here the list starts at line 62, where the program was stopped.
This happens because print_stack_frame, called from both normal_stop
and mi_on_normal_stop, is the function responsible for setting the
current sal from the selected frame, overrides the PRINT_WHAT
argument, and only after that does it decide whether to center the
current sal line or not, based on the overridden value, and it will
always decide false.
(The print_stack_frame call in mi_on_normal_stop is a little different
from the call in normal_stop, in that it is an unconditional
SRC_AND_LOC call. A future patch will make those uniform.)
A previous version of this patch made MI uniform with CLI here, by
making print_stack_frame also center when MI is active. That changed
the output of a "list" command in mi-cli.exp, to expect line 57
instead of 62, as per the example above.
However, looking deeper, that list in question is the first "list"
after the program stops, and right after the stop, before the "list",
the test did "set listsize 1". Let's try the same thing with the CLI:
(gdb) start
62 callee1 (2, "A string argument.", 3.5);
(gdb) set listsize 1
(gdb) list
57 {
Huh, that's unexpected. Why the 57? It's because print_stack_frame,
called in reaction to the breakpoint stop, expecting the next "list"
to show 10 lines (the listsize at the time) around line 62, sets the
lines listed range to 57-67 (62 +/- 5). If the user changes the
listsize before "list", why would we still show that range? Looks
bogus to me.
So the fix for this whole issue should be delay trying to center the
listing to until actually listing, so that the correct listsize can be
taken into account. This makes MI and CLI uniform too, as it deletes
the center code from print_stack_frame.
A series of tests are added to list.exp to cover this. mi-cli.exp was
after all correct all along, but it now gains an additional test that
lists lines with listsize 10, to ensure the centering is consistent
with CLI's.
One related Python test changed related output -- it's a test that
prints the line number after stopping for a breakpoint, similar to the
new list.exp tests. Previously we'd print the stop line minus 5 (due
to the premature centering), now we print the stop line. I think
that's a good change.
Tested on x86_64 Fedora 20.
gdb/
2014-05-21 Pedro Alves <palves@redhat.com>
* cli/cli-cmds.c (list_command): Handle the first "list" after the
current source line having changed.
* frame.h (set_current_sal_from_frame): Remove 'center' parameter.
* infrun.c (normal_stop): Adjust call to
set_current_sal_from_frame.
* source.c (clear_lines_listed_range): New function.
(set_current_source_symtab_and_line, identify_source_line): Clear
the lines listed range.
(line_info): Handle the first "info line" after the current source
line having changed.
* stack.c (print_stack_frame): Remove center handling.
(set_current_sal_from_frame): Remove 'center' parameter. Don't
center sal.line.
gdb/testsuite/
2014-05-21 Pedro Alves <palves@redhat.com>
* gdb.base/list.exp (build_pattern, test_list): New procedures.
Use them to test variations of "list" after reaching a breakpoint.
* gdb.mi/mi-cli.exp (line_main_callme_2): New global.
Test "list" with listsize 10 after reaching a breakpoint.
* gdb.python/python.exp (decode_line current location line
number): Adjust expected line number.
This reverts commit 8c217a4b68.
Following this
https://sourceware.org/ml/gdb-patches/2014-05/msg00462.html
I suggest reverting my previous commit. I will follow with another
patch to add comments, to clarify some things as stated in the mail
thread.
I ran make check with on gdb.mi, and the test that the commit broke
passes again.
gdb/testsuite/ChangeLog:
2014-05-21 Simon Marchi <simon.marchi@ericsson.com>
* lib/mi-support.exp (mi_run_cmd_full): Revert to original
behavior for $args, pass it directly to "run".
Most ports do the same thing in the tail of their mourn routine - call
generic_mourn_inferior+inf_child_maybe_unpush_target.
This factors that out to a convenience function. More could be done,
but this converts only the really obvious ones.
Tested by building GDB on x86_64 Fedora 20, mingw32 and djgpp. The
rest is untested, but I think a patch can't get more obvious.
gdb/
2014-05-21 Pedro Alves <palves@redhat.com>
* inf-child.c (inf_child_mourn_inferior): New function.
* inf-child.h (inf_child_mourn_inferior): New declaration.
* darwin-nat.c (darwin_mourn_inferior): Use
inf_child_mourn_inferior.
* gnu-nat.c (gnu_mourn_inferior): Likewise.
* inf-ptrace.c (inf_ptrace_mourn_inferior): Likewise.
* inf-ttrace.c (inf_ttrace_mourn_inferior): Likewise.
* nto-procfs.c (procfs_mourn_inferior): Likewise.
* windows-nat.c (windows_mourn_inferior): Likewise.
This fixes:
PASS: gdb.base/info-macros.exp: info macro -a -- FOO
ERROR: internal buffer is full.
UNRESOLVED: gdb.base/info-macros.exp: info macros 2
ERROR: internal buffer is full.
UNRESOLVED: gdb.base/info-macros.exp: info macros 3
ERROR: internal buffer is full.
UNRESOLVED: gdb.base/info-macros.exp: info macros 4
FAIL: gdb.base/info-macros.exp: info macros *$pc
ERROR: internal buffer is full.
UNRESOLVED: gdb.base/info-macros.exp: next
FAIL: gdb.base/info-macros.exp: info macros
ERROR: internal buffer is full.
UNRESOLVED: gdb.base/info-macros.exp: next
FAIL: gdb.base/info-macros.exp: info macros 6
ERROR: internal buffer is full.
UNRESOLVED: gdb.base/info-macros.exp: next
FAIL: gdb.base/info-macros.exp: info macros 7
ERROR: internal buffer is full.
UNRESOLVED: gdb.base/info-macros.exp: info macros info-macros.c:42 (PRMS
gdb/NNNN)
with the arm-eabi target tested on the i686-mingw32 host where GCC
defines enough macros to exhaust expect's 30000 characters of buffer
space.
* lib/gdb.exp (default_gdb_init): Bump `match_max' up from
30000 to 65536.
Sometimes it's useful to be able to disable the automatic connection
to the native target. E.g., sometimes GDB disconnects from the
extended-remote target I was debugging, without me noticing it, and
then I do "run". That starts the program locally, and only after a
little head scratch session do I figure out the program is running
locally instead of remotely as intended. Same thing with "attach",
"info os", etc.
With the patch, we now can have this instead:
(gdb) set auto-connect-native-target off
(gdb) target extended-remote :9999
...
*gdb disconnects*
(gdb) run
Don't know how to run. Try "help target".
To still be able to connect to the native target with
auto-connect-native-target set to off, I've made "target native" work
instead of erroring out as today.
Before:
(gdb) target native
Use the "run" command to start a native process.
After:
(gdb) target native
Done. Use the "run" command to start a process.
(gdb) maint print target-stack
The current target stack is:
- native (Native process)
- exec (Local exec file)
- None (None)
(gdb) run
Starting program: ./a.out
...
I've also wanted this for the testsuite, when running against the
native-extended-gdbserver.exp board (runs against gdbserver in
extended-remote mode). With a non-native-target board, it's always a
bug to launch a program with the native target. Turns out we still
have one such case this patch catches:
(gdb) break main
Breakpoint 1 at 0x4009e5: file ../../../src/gdb/testsuite/gdb.base/coremaker.c, line 138.
(gdb) run
Don't know how to run. Try "help target".
(gdb) FAIL: gdb.base/corefile.exp: run: with core
On the patch itself, probably the least obvious bit is the need to go
through all targets, and move the unpush_target call to after the
generic_mourn_inferior call instead of before. This is what
inf-ptrace.c does too, ever since multi-process support was added.
The reason inf-ptrace.c does things in that order is that in the
current multi-process/single-target model, we shouldn't unpush the
target if there are still other live inferiors being debugged. The
check for that is "have_inferiors ()" (a misnomer nowadays...), which
does:
have_inferiors (void)
{
for (inf = inferior_list; inf; inf = inf->next)
if (inf->pid != 0)
return 1;
It's generic_mourn_inferior that ends up clearing inf->pid, so we need
to call it before the have_inferiors check. To make all native
targets behave the same WRT to explicit "target native", I've added an
inf_child_maybe_unpush_target function that targets call instead of
calling unpush_target directly, and as that includes the
have_inferiors check, I needed to adjust the targets.
Tested on x86_64 Fedora 20, native, and also with the
extended-gdbserver board.
Confirmed a cross build of djgpp gdb still builds.
Smoke tested a cross build of Windows gdb under Wine.
Untested otherwise.
gdb/
2014-05-21 Pedro Alves <palves@redhat.com>
* inf-child.c (inf_child_ops, inf_child_explicitly_opened): New
globals.
(inf_child_open_target): New function.
(inf_child_open): Use inf_child_open_target to push the target
instead of erroring out.
(inf_child_disconnect, inf_child_close)
(inf_child_maybe_unpush_target): New functions.
(inf_child_target): Install inf_child_disconnect and
inf_child_close. Store a pointer to the returned object.
* inf-child.h (inf_child_open_target, inf_child_maybe_unpush): New
declarations.
* target.c (auto_connect_native_target): New global.
(show_default_run_target): New function.
(find_default_run_target): Return NULL if automatically connecting
to the native target is disabled.
(_initialize_target): Install set/show auto-connect-native-target.
* NEWS: Mention "set auto-connect-native-target", and "target
native".
* linux-nat.c (super_close): New global.
(linux_nat_close): Call super_close.
(linux_nat_add_target): Store a pointer to the base class's
to_close method.
* inf-ptrace.c (inf_ptrace_mourn_inferior, inf_ptrace_detach): Use
inf_child_maybe_unpush.
* inf-ttrace.c (inf_ttrace_him): Don't push the target if it is
already pushed.
(inf_ttrace_mourn_inferior): Only unpush the target after mourning
the inferior. Use inf_child_maybe_unpush_target.
(inf_ttrace_attach): Don't push the target if it is already
pushed.
(inf_ttrace_detach): Use inf_child_maybe_unpush_target.
* darwin-nat.c (darwin_mourn_inferior): Only unpush the target
after mourning the inferior. Use inf_child_maybe_unpush_target.
(darwin_attach_pid): Don't push the target if it is already
pushed.
* gnu-nat.c (gnu_mourn_inferior): Only unpush the target after
mourning the inferior. Use inf_child_maybe_unpush_target.
(gnu_detach): Use inf_child_maybe_unpush_target.
* go32-nat.c (go32_create_inferior): Don't push the target if it
is already pushed.
(go32_mourn_inferior): Use inf_child_maybe_unpush_target.
* nto-procfs.c (procfs_is_nto_target): Adjust comment.
(procfs_open): Rename to ...
(procfs_open_1): ... this. Add target_ops parameter. Adjust
comments. Can target_preopen before changing node. Call
inf_child_open_target to push the target explicitly.
(procfs_attach): Don't push the target if it is already pushed.
(procfs_detach): Use inf_child_maybe_unpush_target.
(procfs_create_inferior): Don't push the target if it is already
pushed.
(nto_native_ops): New global.
(procfs_open): Reimplement.
(procfs_native_open): New function.
(init_procfs_targets): Install procfs_native_open as to_open of
"target native". Store a pointer to the "native" target in
nto_native_ops.
* procfs.c (procfs_attach): Don't push the target if it is already
pushed.
(procfs_detach): Use inf_child_maybe_unpush_target.
(procfs_mourn_inferior): Only unpush the target after mourning the
inferior. Use inf_child_maybe_unpush_target.
(procfs_init_inferior): Don't push the target if it is already
pushed.
* windows-nat.c (do_initial_windows_stuff): Don't push the target
if it is already pushed.
(windows_detach): Use inf_child_maybe_unpush_target.
(windows_mourn_inferior): Only unpush the target after mourning
the inferior. Use inf_child_maybe_unpush_target.
gdb/doc/
2014-05-21 Pedro Alves <palves@redhat.com>
* gdb.texinfo (Starting): Document "set/show
auto-connect-native-target".
(Target Commands): Document "target native".
gdb/testsuite/
2014-05-21 Pedro Alves <palves@redhat.com>
* boards/gdbserver-base.exp (GDBFLAGS): Set to "set
auto-connect-native-target off".
* gdb.base/auto-connect-native-target.c: New file.
* gdb.base/auto-connect-native-target.exp: New file.
gdb/
2014-05-21 Pedro Alves <palves@redhat.com>
* NEWS: Mention that the "child", "GNU, "djgpp", "darwin-child"
and "procfs" targets are now called "native" instead.
Although the string says "Done.", nothing is pushing the target as is.
Removing the method override let's us fall through to the the base
to_open implemention in inf-child.c, which will push the target in
reaction to "target native" in a follow up patch.
gdb/
2014-05-21 Pedro Alves <palves@redhat.com>
* go32-nat.c (go32_open): Delete.
(go32_target): Don't override the to_open method.
This makes QNX/NTO end up with two targets. It preserves "target
procfs <node>", and adds a "native" target to be like other native
ports.
Not tested.
gdb/
2014-05-21 Pedro Alves <palves@redhat.com>
* nto-procfs.c (procfs_can_run): New function.
(nto_procfs_ops): New global.
(init_procfs_targets): New, based on procfs_target. Install
"target native" in addition to "target procfs".
(_initialize_procfs): Call init_procfs_targets instead of adding
the target here.
To be like other native targets.
Leave to_shortname, to_longname, to_doc as inf-child.c sets them:
t->to_shortname = "native";
t->to_longname = "Native process";
t->to_doc = "Native process (started by the \"run\" command).";
gdb/
2014-05-21 Pedro Alves <palves@redhat.com>
* windows-nat.c (windows_target): Don't override to_shortname,
to_longname or to_doc.
To be like other native targets.
Leave to_shortname, to_longname, to_doc as inf-child.c sets them:
t->to_shortname = "native";
t->to_longname = "Native process";
t->to_doc = "Native process (started by the \"run\" command).";
gdb/
2014-05-21 Pedro Alves <palves@redhat.com>
* gnu-nat.c (gnu): Don't override to_shortname, to_longname or
to_doc.
To be like other native targets.
Leave to_shortname, to_longname, to_doc as inf-child.c sets them:
t->to_shortname = "native";
t->to_longname = "Native process";
t->to_doc = "Native process (started by the \"run\" command).";
gdb/
2014-05-21 Pedro Alves <palves@redhat.com>
* darwin-nat.c (_initialize_darwin_inferior): Don't override
to_shortname, to_longname or to_doc.
To be like other native targets.
Leave to_shortname, to_longname, to_doc as inf-child.c sets them:
t->to_shortname = "native";
t->to_longname = "Native process";
t->to_doc = "Native process (started by the \"run\" command).";
gdb/
2014-05-21 Pedro Alves <palves@redhat.com>
* go32-nat.c (go32_target): Don't override to_shortname,
to_longname or to_doc.
I had been pondering renaming "target child" to something else.
"child" is a little lie in case of "attach", and not exactly very
clear to users, IMO. By best suggestion is "target native". If I
were to explain what "target child" is, I'd just start out with "it's
the native target" anyway. I was worrying a little that "native"
might be a lie too if some port comes up with a default target that
can run but is not really native, but I think that's a very minor
issue - we can consider that "native" really means the default built
in target that GDB supports, instead of saying that's the target that
debugs host native processes, if it turns out necessary.
This change doesn't affect users much, because "target child" results
in error today:
(gdb) target child
Use the "run" command to start a child process.
Other places "child" is visible:
(gdb) help target
...
List of target subcommands:
target child -- Child process (started by the "run" command)
target core -- Use a core file as a target
target exec -- Use an executable file as a target
...
(gdb) info target
Symbols from "/home/pedro/gdb/mygit/build/gdb/gdb".
Child process:
Using the running image of child Thread 0x7ffff7fc9740 (LWP 4818).
While running this, GDB does not access memory from...
...
These places will say "native" instead. I think that's a good thing.
gdb/
2014-05-21 Pedro Alves <palves@redhat.com>
* inf-child.c (inf_child_open): Remove mention of "child".
(inf_child_target): Rename target to "native" instead of "child".
gdb/testsuite/
2014-05-21 Pedro Alves <palves@redhat.com>
* gdb.base/default.exp: Test "target native" instead of "target
child".
Now that all invocations of regset_alloc() have been removed, the
function is dropped. Since regset_alloc() was the only function
provided by regset.c, this source file is removed as well.
Clear the naming confusion about "regset" versus "sparc*regset". The
latter was used to represent the *map* of a register set, not the
register set itself, and is thus renamed accordingly.
The following identifiers are renamed:
sparc32_bsd_fpregset => sparc32_bsd_fpregmap
sparc32_linux_core_gregset => sparc32_linux_core_gregmap
sparc32_sol2_fpregset => sparc32_sol2_fpregmap
sparc32_sol2_gregset => sparc32_sol2_gregmap
sparc32_sunos4_fpregset => sparc32_sunos4_fpregmap
sparc32_sunos4_gregset => sparc32_sunos4_gregmap
sparc32nbsd_gregset => sparc32nbsd_gregmap
sparc64_bsd_fpregset => sparc64_bsd_fpregmap
sparc64_linux_core_gregset => sparc64_linux_core_gregmap
sparc64_linux_ptrace_gregset => sparc64_linux_ptrace_gregmap
sparc64_sol2_fpregset => sparc64_sol2_fpregmap
sparc64_sol2_gregset => sparc64_sol2_gregmap
sparc64fbsd_gregset => sparc64fbsd_gregmap
sparc64nbsd_gregset => sparc64nbsd_gregmap
sparc64obsd_core_gregset => sparc64obsd_core_gregmap
sparc64obsd_gregset => sparc64obsd_gregmap
sparc_fpregset => sparc_fpregmap
sparc_gregset => sparc_gregmap
sparc_sol2_fpregset => sparc_sol2_fpregmap
sparc_sol2_gregset => sparc_sol2_gregmap
Also, all local variables 'gregset' and 'fpregset' are renamed to
'gregmap' and 'fpregmap', respectively.
Removes the 'arch' field from the regset structure, since it
represents the only "dynamic" data in a regset. It was referenced in
some regset supply- and collect routines, to get access to the gdbarch
associated with the regset. Naturally, the affected routines always
have access to the regcache to be supplied to or collected from. Thus
the gdbarch associated with that regcache can be used instead.
I have posted:
TLS variables access for -static -lpthread executables
https://sourceware.org/ml/libc-help/2014-03/msg00024.html
and the GDB patch below has been confirmed as OK for current glibcs.
Further work should be done for newer glibcs:
Improve TLS variables glibc compatibility
https://sourceware.org/bugzilla/show_bug.cgi?id=16954
Still the patch below implements the feature in a fully functional way backward
compatible with current glibcs, it depends on the following glibc source line:
csu/libc-tls.c
main_map->l_tls_modid = 1;
gdb/
2014-05-21 Jan Kratochvil <jan.kratochvil@redhat.com>
Fix TLS access for -static -pthread.
* linux-thread-db.c (struct thread_db_info): Add td_thr_tlsbase_p.
(try_thread_db_load_1): Initialize it.
(thread_db_get_thread_local_address): Call it if LM is zero.
* target.c (target_translate_tls_address): Remove LM_ADDR zero check.
* target.h (struct target_ops) (to_get_thread_local_address): Add
load_module_addr comment.
gdb/gdbserver/
2014-05-21 Jan Kratochvil <jan.kratochvil@redhat.com>
Fix TLS access for -static -pthread.
* gdbserver/thread-db.c (struct thread_db): Add td_thr_tlsbase_p.
(thread_db_get_tls_address): Call it if LOAD_MODULE is zero.
(thread_db_load_search, try_thread_db_load_1): Initialize it.
gdb/testsuite/
2014-05-21 Jan Kratochvil <jan.kratochvil@redhat.com>
Fix TLS access for -static -pthread.
* gdb.threads/staticthreads.c <HAVE_TLS> (tlsvar): New.
<HAVE_TLS> (thread_function, main): Initialize it.
* gdb.threads/staticthreads.exp: Try gdb_compile_pthreads for $have_tls.
Add clean_restart.
<$have_tls != "">: Check TLSVAR.
Message-ID: <20140410115204.GB16411@host2.jankratochvil.net>
The dcache (code/stack cache) is supposed to be transparent, but it's
actually not in one case. dcache tries to read chunks (cache lines)
at a time off of the target. This may end up trying to read
unaccessible or unavailable memory. Currently the caller gets an xfer
error in this case. But if the specific bits of memory the caller
actually wanted are available and accessible, then the caller should
get the memory it wanted, not an error.
gdb/
2014-05-21 Pedro Alves <palves@redhat.com>
* dcache.c (dcache_read_memory_partial): If reading the cache line
fails, fallback to reading just the memory the caller wanted.
gdb/testsuite/
2014-05-21 Pedro Alves <palves@redhat.com>
* gdb.base/dcache-line-read-error.c: New.
* gdb.base/dcache-line-read-error.exp: New.
UNRESOLVED: gdb.multi/base.exp: remove-inferiors 2-3
UNRESOLVED: gdb.multi/base.exp: check remove-inferiors
gdb is crashing because it's accessing/freeing already freed memory.
==16368== Invalid read of size 4
==16368== at 0x660A9D: find_pc_section (binutils-gdb/gdb/objfiles.c:1349)
==16368== by 0x663ECB: lookup_minimal_symbol_by_pc_section (binutils-gdb/gdb/minsyms.c:734)
==16368== by 0x5D987A: find_pc_sect_symtab (binutils-gdb/gdb/symtab.c:2153)
==16368== by 0x5D4D77: blockvector_for_pc_sect (binutils-gdb/gdb/block.c:168)
==16368== by 0x5D4F59: block_for_pc_sect (binutils-gdb/gdb/block.c:246)
==16368== by 0x5D4F9B: block_for_pc (binutils-gdb/gdb/block.c:258)
==16368== by 0x734C5D: inline_frame_sniffer (binutils-gdb/gdb/inline-frame.c:218)
==16368== by 0x732104: frame_unwind_try_unwinder (binutils-gdb/gdb/frame-unwind.c:108)
==16368== by 0x73223F: frame_unwind_find_by_frame (binutils-gdb/gdb/frame-unwind.c:159)
==16368== by 0x72D5AA: compute_frame_id (binutils-gdb/gdb/frame.c:453)
==16368== by 0x7300EC: get_prev_frame_if_no_cycle (binutils-gdb/gdb/frame.c:1758)
==16368== by 0x73079A: get_prev_frame_always (binutils-gdb/gdb/frame.c:1931)
==16368== Address 0x5b13500 is 16 bytes inside a block of size 24 free'd
==16368== at 0x403072E: free (valgrind/coregrind/m_replacemalloc/vg_replace_malloc.c:445)
==16368== by 0x762134: xfree (binutils-gdb/gdb/common/common-utils.c:108)
==16368== by 0x65DACF: objfiles_pspace_data_cleanup (binutils-gdb/gdb/objfiles.c:91)
==16368== by 0x75E546: program_spaceregistry_callback_adaptor (binutils-gdb/gdb/progspace.c:45)
==16368== by 0x7644F6: registry_clear_data (binutils-gdb/gdb/registry.c:82)
==16368== by 0x7645AB: registry_container_free_data (binutils-gdb/gdb/registry.c:95)
==16368== by 0x75E5B4: program_space_free_data (binutils-gdb/gdb/progspace.c:45)
==16368== by 0x75E9BA: release_program_space (binutils-gdb/gdb/progspace.c:167)
==16368== by 0x75EB9B: prune_program_spaces (binutils-gdb/gdb/progspace.c:269)
==16368== by 0x75303D: remove_inferior_command (binutils-gdb/gdb/inferior.c:792)
==16368== by 0x50B5FD: do_cfunc (binutils-gdb/gdb/cli/cli-decode.c:107)
==16368== by 0x50E6F2: cmd_func (binutils-gdb/gdb/cli/cli-decode.c:1886)
The problem originates from the get_current_arch call in
py-progspace.c:py_free_pspace. The inferior associated with the
pspace is gone, and the current inferior is a different one and is running.
Therefore get_current_arch tries to read the current frame which
causes reads of data in the current program space which we've just deleted.
* python/py-progspace.c (py_free_pspace): Call target_gdbarch
instead of get_current_arch.
This does two things:
1. Adds a test.
Recently compare-sections got a new "-r" switch, but given no test
existed for compare-sections, the patch was allowed in with no
testsuite addition. This now adds a test for both compare-sections
and compare-sections -r.
2. Makes the compare-sections command work against all targets.
Currently, compare-sections only works with remote targets, and only
those that support the qCRC packet. The patch makes it so that if the
target doesn't support accelerating memory verification, then GDB
falls back to comparing memory itself. This is of course slower, but
it's better than nothing, IMO. While testing against extended-remote
GDBserver I noticed that we send the qCRC request to the target if
we're connected, but not yet running a program. That can't work of
course -- the patch fixes that. This all also goes in the direction
of bridging the local/remote parity gap.
I didn't decouple 1. from 2., because that would mean that the test
would need to handle the case of the target not supporting the
command.
Tested on x86_64 Fedora 17, native, remote GDBserver, and
extended-remote GDBserver. I also hack-disabled qCRC support to make
sure the fallback paths in remote.c work.
gdb/doc/
2014-05-20 Pedro Alves <palves@redhat.com>
* gdb.texinfo (Memory) <compare-sections>: Generalize comments to
not be remote specific. Add cross reference to the qCRC packet.
(Separate Debug Files): Update cross reference to the qCRC packet.
(General Query Packets) <qCRC packet>: Add anchor.
gdb/
2014-05-20 Pedro Alves <palves@redhat.com>
* NEWS: Mention that compare-sections now works with all targets.
* remote.c (PACKET_qCRC): New enum value.
(remote_verify_memory): Don't send qCRC if the target has no
execution. Use packet_support/packet_ok. If the target doesn't
support the qCRC packet, fallback to a deep memory copy.
(compare_sections_command): Say "target image" instead of "remote
executable".
(_initialize_remote): Add PACKET_qCRC to the list of config
packets that have no associated command. Extend comment.
* target.c (simple_verify_memory, default_verify_memory): New
function.
* target.h (struct target_ops) <to_verify_memory>: Default to
default_verify_memory.
(simple_verify_memory): New declaration.
* target-delegates.c: Regenerate.
gdb/testsuite/
2014-05-20 Pedro Alves <palves@redhat.com>
* gdb.base/compare-sections.c: New file.
* gdb.base/compare-sections.exp: New file.
This patch fixes hardware breakpoint regressions exposed by my fix for
"PR breakpoints/7143 - Watchpoint does not trigger when first set", at
https://sourceware.org/ml/gdb-patches/2014-03/msg00167.html
The testsuite caught them on Linux/x86_64, at least. gdb.sum:
gdb.sum:
FAIL: gdb.base/hbreak2.exp: next over recursive call
FAIL: gdb.base/hbreak2.exp: backtrace from factorial(5.1)
FAIL: gdb.base/hbreak2.exp: continue until exit at recursive next test
gdb.log:
(gdb) next
Program received signal SIGTRAP, Trace/breakpoint trap.
factorial (value=4) at ../../../src/gdb/testsuite/gdb.base/break.c:113
113 if (value > 1) { /* set breakpoint 7 here */
(gdb) FAIL: gdb.base/hbreak2.exp: next over recursive call
Actually, that patch just exposed a latent issue to "breakpoints
always-inserted off" mode, not really caused it. After that patch,
GDB no longer removes breakpoints at each internal event, thus making
some scenarios behave like breakpoint always-inserted on. The bug is
easy to trigger with always-inserted on.
The issue is that since the target-side breakpoint conditions support,
if the stub/server supports evaluating breakpoint conditions on the
target side, then GDB is sending duplicate Zx packets to the target
without removing them before, and GDBserver is not really expecting
that for Z packets other than Z0/z0. E.g., with "set breakpoint
always-inserted on" and "set debug remote 1":
(gdb) b main
Sending packet: $m410943,1#ff...Packet received: 48
Breakpoint 4 at 0x410943: file ../../../src/gdb/gdbserver/server.c, line 3028.
Sending packet: $Z0,410943,1#48...Packet received: OK
^^^^^^^^^^^^
(gdb) b main
Note: breakpoint 4 also set at pc 0x410943.
Sending packet: $m410943,1#ff...Packet received: 48
Breakpoint 5 at 0x410943: file ../../../src/gdb/gdbserver/server.c, line 3028.
Sending packet: $Z0,410943,1#48...Packet received: OK
^^^^^^^^^^^^
(gdb) b main
Note: breakpoints 4 and 5 also set at pc 0x410943.
Sending packet: $m410943,1#ff...Packet received: 48
Breakpoint 6 at 0x410943: file ../../../src/gdb/gdbserver/server.c, line 3028.
Sending packet: $Z0,410943,1#48...Packet received: OK
^^^^^^^^^^^^
(gdb) del
Delete all breakpoints? (y or n) y
Sending packet: $Z0,410943,1#48...Packet received: OK
Sending packet: $Z0,410943,1#48...Packet received: OK
Sending packet: $z0,410943,1#68...Packet received: OK
And for Z1, similarly:
(gdb) hbreak main
Sending packet: $m410943,1#ff...Packet received: 48
Hardware assisted breakpoint 4 at 0x410943: file ../../../src/gdb/gdbserver/server.c, line 3028.
Sending packet: $Z1,410943,1#49...Packet received: OK
^^^^^^^^^^^^
Packet Z1 (hardware-breakpoint) is supported
(gdb) hbreak main
Note: breakpoint 4 also set at pc 0x410943.
Sending packet: $m410943,1#ff...Packet received: 48
Hardware assisted breakpoint 5 at 0x410943: file ../../../src/gdb/gdbserver/server.c, line 3028.
Sending packet: $Z1,410943,1#49...Packet received: OK
^^^^^^^^^^^^
(gdb) hbreak main
Note: breakpoints 4 and 5 also set at pc 0x410943.
Sending packet: $m410943,1#ff...Packet received: 48
Hardware assisted breakpoint 6 at 0x410943: file ../../../src/gdb/gdbserver/server.c, line 3028.
Sending packet: $Z1,410943,1#49...Packet received: OK
^^^^^^^^^^^^
(gdb) del
Delete all breakpoints? (y or n) y
Sending packet: $Z1,410943,1#49...Packet received: OK
^^^^^^^^^^^^
Sending packet: $Z1,410943,1#49...Packet received: OK
^^^^^^^^^^^^
Sending packet: $z1,410943,1#69...Packet received: OK
^^^^^^^^^^^^
So GDB sent a bunch of Z1 packets, and then when finally removing the
breakpoint, only one z1 packet was sent. On the GDBserver side (with
monitor set debug-hw-points 1), in the Z1 case, we see:
$ ./gdbserver :9999 ./gdbserver
Process ./gdbserver created; pid = 8629
Listening on port 9999
Remote debugging from host 127.0.0.1
insert_watchpoint (addr=410943, len=1, type=instruction-execute):
CONTROL (DR7): 00000101 STATUS (DR6): 00000000
DR0: addr=0x410943, ref.count=1 DR1: addr=0x0, ref.count=0
DR2: addr=0x0, ref.count=0 DR3: addr=0x0, ref.count=0
insert_watchpoint (addr=410943, len=1, type=instruction-execute):
CONTROL (DR7): 00000101 STATUS (DR6): 00000000
DR0: addr=0x410943, ref.count=2 DR1: addr=0x0, ref.count=0
DR2: addr=0x0, ref.count=0 DR3: addr=0x0, ref.count=0
insert_watchpoint (addr=410943, len=1, type=instruction-execute):
CONTROL (DR7): 00000101 STATUS (DR6): 00000000
DR0: addr=0x410943, ref.count=3 DR1: addr=0x0, ref.count=0
DR2: addr=0x0, ref.count=0 DR3: addr=0x0, ref.count=0
insert_watchpoint (addr=410943, len=1, type=instruction-execute):
CONTROL (DR7): 00000101 STATUS (DR6): 00000000
DR0: addr=0x410943, ref.count=4 DR1: addr=0x0, ref.count=0
DR2: addr=0x0, ref.count=0 DR3: addr=0x0, ref.count=0
insert_watchpoint (addr=410943, len=1, type=instruction-execute):
CONTROL (DR7): 00000101 STATUS (DR6): 00000000
DR0: addr=0x410943, ref.count=5 DR1: addr=0x0, ref.count=0
DR2: addr=0x0, ref.count=0 DR3: addr=0x0, ref.count=0
remove_watchpoint (addr=410943, len=1, type=instruction-execute):
CONTROL (DR7): 00000101 STATUS (DR6): 00000000
DR0: addr=0x410943, ref.count=4 DR1: addr=0x0, ref.count=0
DR2: addr=0x0, ref.count=0 DR3: addr=0x0, ref.count=0
That's one insert_watchpoint call for each Z1 packet, and then one
remove_watchpoint call for the z1 packet. Notice how ref.count
increased for each insert_watchpoint call, and then in the end, after
GDB told GDBserver to forget about the hardware breakpoint, GDBserver
ends with the the first debug register still with ref.count=4! IOW,
the hardware breakpoint is left armed on the target, while on the GDB
end it's gone. If the program happens to execute 0x410943 afterwards,
then the CPU traps, GDBserver reports the trap to GDB, and GDB not
having a breakpoint set at that address anymore, reports to the user a
spurious SIGTRAP.
This is exactly what is happening in the hbreak2.exp test, though in
that case, it's a shared library event that triggers a
breakpoint_re_set, when breakpoints are still inserted (because
nowadays GDB doesn't remove breakpoints while handling internal
events), and that recreates breakpoint locations, which likewise
forces breakpoint reinsertion and Zx packet resends...
That is a lot of bogus Zx duplication that should possibly be
addressed on the GDB side. GDB resends Zx packets because the way to
change the target-side condition, is to resend the breakpoint to the
server with the new condition. (That's an option in the packet: e.g.,
"Z1,410943,1;X3,220027" for "hbreak main if 0". The packets in the
examples above are shorter because the breakpoints don't have
conditions attached). GDB doesn't remove the breakpoint first before
reinserting it because that'd be bad for non-stop, as it'd open a
window where the inferior could miss the breakpoint. The conditions
actually haven't changed between the resends, but GDB isn't smart
enough to realize that.
(TBC, if the target doesn't support target-side conditions, then GDB
doesn't trigger these resends (init_bp_location calls
mark_breakpoint_location_modified, and that does nothing if condition
evaluation is on the host side. The resends are caused by the
'loc->condition_changed = condition_modified.' line.)
But, even if GDB was made smarter, GDBserver should really still
handle the resends anyway. So target-side conditions also aren't
really to blame. The documentation of the Z/z packets says:
"To avoid potential problems with duplicate packets, the operations
should be implemented in an idempotent way."
As such, we may want to fix GDB, but we should definitely fix
GDBserver. The fix is a prerequisite for target-side conditions on
hardware breakpoints anyway (and while at it, on watchpoints too).
GDBserver indeed already treats duplicate Z0 packets in an idempotent
way. mem-break.c has the concept of high-level and low-level
breakpoints, somewhat similar to GDB's split of breakpoints vs
breakpoint locations, and keeps track of multiple breakpoints
referencing the same address/location, for the case of an internal
GDBserver breakpoint or a tracepoint being set at the same address as
a GDB breakpoint. But, it only allows GDB to ever contribute one
reference to a software breakpoint location. IOW, if gdbserver sees a
Z0 packet for the same address where it already had a GDB breakpoint
set, then GDBserver won't create another high-level GDB breakpoint.
However, mem-break.c only tracks GDB Z0 breakpoints. The same logic
should apply to all kinds of Zx packets. Currently, gdbserver passes
down each duplicate Zx (other than Z0) request directly to the
target->insert_point routine. The x86 watchpoint support itself
refcounts watchpoint / hw breakpoint requests, to handle overlapping
watchpoints, and save debug registers. But that code doesn't (and
really shouldn't) handle the duplicate requests, assuming that for
each insert there will be a corresponding remove.
So the fix is to generalize mem-break.c to track all kinds of Zx
breakpoints, and filter out duplicates. As mentioned, this ends up
adding support for target-side conditions on hardware breakpoints and
watchpoints too (though GDB itself doesn't support the latter yet).
Probably the least obvious change in the patch is that it kind of
turns the breakpoint insert/remove APIs inside out. Before, the
target methods were only called for GDB breakpoints. The internal
breakpoint set/delete methods inserted memory breakpoints directly
bypassing the insert/remove target methods. That's not good when the
target should use a debug API to set software breakpoints, instead of
relying on GDBserver patching memory with breakpoint instructions, as
is the case of NTO.
Now removal/insertion of all kinds of breakpoints/watchpoints, either
internal, or from GDB, always go through the target methods. The
insert_point/remove_point methods no longer get passed a Z packet
type, but an internal/raw breakpoint type. They're also passed a
pointer to the raw breakpoint itself (note that's still opaque outside
mem-break.c), so that insert_memory_breakpoint /
remove_memory_breakpoint have access to the breakpoint's shadow
buffer. I first tried passing down a new structure based on GDB's
"struct bp_target_info" (actually with that name exactly), but then
decided against it as unnecessary complication.
As software/memory breakpoints work by poking at memory, when setting
a GDB Z0 breakpoint (but not internal breakpoints, as those can assume
the conditions are already right), we need to tell the target to
prepare to access memory (which on Linux means stop threads). If that
operation fails, we need to return error to GDB. Seeing an error, if
this is the first breakpoint of that type that GDB tries to insert,
GDB would then assume the breakpoint type is supported, but it may
actually not be. So we need to check whether the type is supported at
all before preparing to access memory. And to solve that, the patch
adds a new target->supports_z_point_type method that is called before
actually trying to insert the breakpoint.
Other than that, hopefully the change is more or less obvious.
New test added that exercises the hbreak2.exp regression in a more
direct way, without relying on a breakpoint re-set happening before
main is reached.
Tested by building GDBserver for:
aarch64-linux-gnu
arm-linux-gnueabihf
i686-pc-linux-gnu
i686-w64-mingw32
m68k-linux-gnu
mips-linux-gnu
mips-uclinux
nios2-linux-gnu
powerpc-linux-gnu
sh-linux-gnu
tilegx-unknown-linux-gnu
x86_64-redhat-linux
x86_64-w64-mingw32
And also regression tested on x86_64 Fedora 20.
gdb/gdbserver/
2014-05-20 Pedro Alves <palves@redhat.com>
* linux-aarch64-low.c (aarch64_insert_point)
(aarch64_remove_point): No longer check whether the type is
supported here. Adjust to new interface.
(the_low_target): Install aarch64_supports_z_point_type as
supports_z_point_type method.
* linux-arm-low.c (raw_bkpt_type_to_arm_hwbp_type): New function.
(arm_linux_hw_point_initialize): Take an enum raw_bkpt_type
instead of a Z packet char. Adjust.
(arm_supports_z_point_type): New function.
(arm_insert_point, arm_remove_point): Adjust to new interface.
(the_low_target): Install arm_supports_z_point_type.
* linux-crisv32-low.c (cris_supports_z_point_type): New function.
(cris_insert_point, cris_remove_point): Adjust to new interface.
Don't check whether the type is supported here.
(the_low_target): Install cris_supports_z_point_type.
* linux-low.c (linux_supports_z_point_type): New function.
(linux_insert_point, linux_remove_point): Adjust to new interface.
* linux-low.h (struct linux_target_ops) <insert_point,
remove_point>: Take an enum raw_bkpt_type instead of a char. Add
raw_breakpoint pointer parameter.
<supports_z_point_type>: New method.
* linux-mips-low.c (mips_supports_z_point_type): New function.
(mips_insert_point, mips_remove_point): Adjust to new interface.
Use mips_supports_z_point_type.
(the_low_target): Install mips_supports_z_point_type.
* linux-ppc-low.c (the_low_target): Install NULL as
supports_z_point_type method.
* linux-s390-low.c (the_low_target): Install NULL as
supports_z_point_type method.
* linux-sparc-low.c (the_low_target): Install NULL as
supports_z_point_type method.
* linux-x86-low.c (x86_supports_z_point_type): New function.
(x86_insert_point): Adjust to new insert_point interface. Use
insert_memory_breakpoint. Adjust to new
i386_low_insert_watchpoint interface.
(x86_remove_point): Adjust to remove_point interface. Use
remove_memory_breakpoint. Adjust to new
i386_low_remove_watchpoint interface.
(the_low_target): Install x86_supports_z_point_type.
* lynx-low.c (lynx_target_ops): Install NULL as
supports_z_point_type callback.
* nto-low.c (nto_supports_z_point_type): New.
(nto_insert_point, nto_remove_point): Adjust to new interface.
(nto_target_ops): Install nto_supports_z_point_type.
* mem-break.c: Adjust intro comment.
(struct raw_breakpoint) <raw_type, size>: New fields.
<inserted>: Update comment.
<shlib_disabled>: Delete field.
(enum bkpt_type) <gdb_breakpoint>: Delete value.
<gdb_breakpoint_Z0, gdb_breakpoint_Z1, gdb_breakpoint_Z2,
gdb_breakpoint_Z3, gdb_breakpoint_Z4>: New values.
(raw_bkpt_type_to_target_hw_bp_type): New function.
(find_enabled_raw_code_breakpoint_at): New function.
(find_raw_breakpoint_at): New type and size parameters. Use them.
(insert_memory_breakpoint): New function, based off
set_raw_breakpoint_at.
(remove_memory_breakpoint): New function.
(set_raw_breakpoint_at): Reimplement.
(set_breakpoint): New, based on set_breakpoint_at.
(set_breakpoint_at): Reimplement.
(delete_raw_breakpoint): Go through the_target->remove_point
instead of assuming memory breakpoints.
(find_gdb_breakpoint_at): Delete.
(Z_packet_to_bkpt_type, Z_packet_to_raw_bkpt_type): New functions.
(find_gdb_breakpoint): New function.
(set_gdb_breakpoint_at): Delete.
(z_type_supported): New function.
(set_gdb_breakpoint_1): New function, loosely based off
set_gdb_breakpoint_at.
(check_gdb_bp_preconditions, set_gdb_breakpoint): New functions.
(delete_gdb_breakpoint_at): Delete.
(delete_gdb_breakpoint_1): New function, loosely based off
delete_gdb_breakpoint_at.
(delete_gdb_breakpoint): New function.
(clear_gdb_breakpoint_conditions): Rename to ...
(clear_breakpoint_conditions): ... this. Don't handle a NULL
breakpoint.
(add_condition_to_breakpoint): Make static.
(add_breakpoint_condition): Take a struct breakpoint pointer
instead of an address. Adjust.
(gdb_condition_true_at_breakpoint): Rename to ...
(gdb_condition_true_at_breakpoint_z_type): ... this, and add
z_type parameter.
(gdb_condition_true_at_breakpoint): Reimplement.
(add_breakpoint_commands): Take a struct breakpoint pointer
instead of an address. Adjust.
(gdb_no_commands_at_breakpoint): Rename to ...
(gdb_no_commands_at_breakpoint_z_type): ... this. Add z_type
parameter. Return true if no breakpoint was found. Change debug
output.
(gdb_no_commands_at_breakpoint): Reimplement.
(run_breakpoint_commands): Rename to ...
(run_breakpoint_commands_z_type): ... this. Add z_type parameter,
and change return type to boolean.
(run_breakpoint_commands): New function.
(gdb_breakpoint_here): Also check for Z1 breakpoints.
(uninsert_raw_breakpoint): Don't try to reinsert a disabled
breakpoint. Go through the_target->remove_point instead of
assuming memory breakpoint.
(uninsert_breakpoints_at, uninsert_all_breakpoints): Uninsert
software and hardware breakpoints.
(reinsert_raw_breakpoint): Go through the_target->insert_point
instead of assuming memory breakpoint.
(reinsert_breakpoints_at, reinsert_all_breakpoints): Reinsert
software and hardware breakpoints.
(check_breakpoints, breakpoint_here, breakpoint_inserted_here):
Check both software and hardware breakpoints.
(validate_inserted_breakpoint): Assert the breakpoint is a
software breakpoint. Set the inserted flag to -1 instead of
setting shlib_disabled.
(delete_disabled_breakpoints): Adjust.
(validate_breakpoints): Only validate software breakpoints.
Adjust to inserted flag change.
(check_mem_read, check_mem_write): Skip breakpoint types other
than software breakpoints. Adjust to inserted flag change.
* mem-break.h (enum raw_bkpt_type): New enum.
(raw_breakpoint, struct process_info): Forward declare.
(Z_packet_to_target_hw_bp_type): Delete declaration.
(raw_bkpt_type_to_target_hw_bp_type, Z_packet_to_raw_bkpt_type)
(set_gdb_breakpoint, delete_gdb_breakpoint)
(clear_breakpoint_conditions): New declarations.
(set_gdb_breakpoint_at, clear_gdb_breakpoint_conditions): Delete.
(breakpoint_inserted_here): Update comment.
(add_breakpoint_condition, add_breakpoint_commands): Replace
address parameter with a breakpoint pointer parameter.
(gdb_breakpoint_here): Update comment.
(delete_gdb_breakpoint_at): Delete.
(insert_memory_breakpoint, remove_memory_breakpoint): Declare.
* server.c (process_point_options): Take a struct breakpoint
pointer instead of an address. Adjust.
(process_serial_event) <Z/z packets>: Use set_gdb_breakpoint and
delete_gdb_breakpoint.
* spu-low.c (spu_target_ops): Install NULL as
supports_z_point_type method.
* target.h: Include mem-break.h.
(struct target_ops) <prepare_to_access_memory>: Update comment.
<supports_z_point_type>: New field.
<insert_point, remove_point>: Take an enum raw_bkpt_type argument
instead of a char. Also take a raw breakpoint pointer.
* win32-arm-low.c (the_low_target): Install NULL as
supports_z_point_type.
* win32-i386-low.c (i386_supports_z_point_type): New function.
(i386_insert_point, i386_remove_point): Adjust to new interface.
(the_low_target): Install i386_supports_z_point_type.
* win32-low.c (win32_supports_z_point_type): New function.
(win32_insert_point, win32_remove_point): Adjust to new interface.
(win32_target_ops): Install win32_supports_z_point_type.
* win32-low.h (struct win32_target_ops):
<supports_z_point_type>: New method.
<insert_point, remove_point>: Take an enum raw_bkpt_type argument
instead of a char. Also take a raw breakpoint pointer.
gdb/testsuite/
2014-05-20 Pedro Alves <palves@redhat.com>
* gdb.base/break-idempotent.c: New file.
* gdb.base/break-idempotent.exp: New file.
The Aarch64, MIPS and x86 Linux backends all have Z packet number
defines and corresponding protocol number to internal type convertion
routines. Factor them all out to gdbserver's core code, so we only
have one shared copy.
Tested on x86_64 Fedora 20, and also cross built for aarch64-linux-gnu
and mips-linux-gnu.
gdb/gdbserver/
2014-05-20 Pedro Alves <palves@redhat.com>
* mem-break.h: Include break-common.h.
(Z_PACKET_SW_BP, Z_PACKET_HW_BP, Z_PACKET_WRITE_WP)
(Z_PACKET_READ_WP, Z_PACKET_ACCESS_WP): New defines.
(Z_packet_to_target_hw_bp_type): New declaration.
* mem-break.c (Z_packet_to_target_hw_bp_type): New function.
* i386-low.c (Z_PACKET_HW_BP, Z_PACKET_WRITE_WP, Z_PACKET_READ_WP)
(Z_PACKET_ACCESS_WP): Delete macros.
(Z_packet_to_hw_type): Delete function.
* i386-low.h: Don't include break-common.h here.
(Z_packet_to_hw_type): Delete declaration.
* linux-x86-low.c (x86_insert_point, x86_insert_point): Call
Z_packet_to_target_hw_bp_type instead of Z_packet_to_hw_type.
* win32-i386-low.c (i386_insert_point, i386_remove_point): Call
Z_packet_to_target_hw_bp_type instead of Z_packet_to_hw_type.
* linux-aarch64-low.c: Don't include break-common.h here.
(Z_PACKET_SW_BP, Z_PACKET_HW_BP, Z_PACKET_WRITE_WP)
(Z_PACKET_READ_WP, Z_PACKET_ACCESS_WP): Delete macros.
(Z_packet_to_target_hw_bp_type): Delete function.
* linux-mips-low.c (rsp_bp_type_to_target_hw_bp_type): Delete
function.
(mips_insert_point, mips_remove_point): Use
Z_packet_to_target_hw_bp_type.
This makes linux-aarch64-low.c use target_hw_bp_type, like gdb's
aarch64-linux-nat.c. The original motivation is decoupling
insert_point/remove_point from Z packet numbers, but I think making
the files a little bit more similar is a good thing on its own right.
Ideally we'd merge these files even... The
aarch64_point_encode_ctrl_reg change is taken straight from GDB's
copy.
I confirmed with a cross compiler that this builds, but it's otherwise
untested.
gdb/gdbserver/
2014-05-20 Pedro Alves <palves@redhat.com>
* linux-aarch64-low.c: Include break-common.h.
(enum target_point_type): Delete.
(Z_packet_to_point_type): Rename to ...
(Z_packet_to_target_hw_bp_type): ... this, and return a
target_hw_bp_type instead.
(aarch64_show_debug_reg_state): Take an enum target_hw_bp_type
instead of an enum target_point_type.
(aarch64_point_encode_ctrl_reg): Likewise. Compute type mask from
breakpoint type.
(aarch64_dr_state_insert_one_point)
(aarch64_dr_state_remove_one_point, aarch64_handle_breakpoint)
(aarch64_handle_aligned_watchpoint)
(aarch64_handle_unaligned_watchpoint, aarch64_handle_watchpoint):
Take an enum target_hw_bp_type instead of an enum
target_point_type.
(aarch64_supports_z_point_type): New function.
(aarch64_insert_point, aarch64_remove_point): Use it. Adjust to
use Z_packet_to_target_hw_bp_type.
