In https://sourceware.org/ml/gdb-patches/2014-10/msg00652.html, Sandra
shows a target that was broken by the recent update_thread_list
optimization:
(gdb) target remote qa8-centos32-cs:10514
...
(gdb) continue
Continuing.
Cannot execute this command without a live selected thread.
(gdb)
The error means that the current thread is in "exited" state when the
continue command is processed. The root of the problem was found
here:
> Sending packet: $Hg0#df...Packet received:
...
> Sending packet: $?#3f...Packet received: S00
> Sending packet: $qfThreadInfo#bb...Packet received: l
> Sending packet: $Hc-1#09...Packet received:
> Sending packet: $qC#b4...Packet received: unset
This target doesn't really support threads (no thread indication in
stop reply packets; no support for qC), but then supports
qfThreadInfo, and returns an empty thread list to GDB.
See https://sourceware.org/ml/gdb-patches/2014-10/msg00665.html for
why the target does that.
As remote_update_thread_list deletes threads from GDB's list that are
not found in the thread list that the target reports, the result is
that GDB deletes the "fake" main thread that GDB added itself. (As
that thread is currently selected, it is marked "exited" instead of
being deleted straight away.)
This commit avoids deleting the main thread in this scenario.
gdb/
2014-10-27 Pedro Alves <palves@redhat.com>
* remote.c (remote_thread_alive): New, factored out from ...
(remote_thread_alive): ... this.
(remote_update_thread_list): Bail out before deleting threads if
the target returned an empty list, and, the current thread has a
magic/fake ptid.
clear_threads_listing_context is used for thread listing methods other
than the xml based, but it's only defined when HAVE_LIBEXPAT is defined.
gdb/
2014-10-17 Pedro Alves <palves@redhat.com>
* remote.c (clear_threads_listing_context): Move higher up, out of
the HAVE_LIBEXPAT guard.
This commit avoids the prune_threads call in the remote target's
target_update_thread_list's implementation, eliminating all the "thread
alive" RSP traffic (one packet per thread) whenever we fetch the
thread list.
IOW, this:
Sending packet: $Tp2141.2150#82...Packet received: OK
Sending packet: $Tp2141.214f#b7...Packet received: OK
Sending packet: $Tp2141.2141#82...Packet received: OK
... more T packets; it's one per previously known live thread ...
Sending packet: $qXfer:threads:read::0,fff#03...Packet received: l<threads>\n<thread id="p2141.2141" core="2"/>\n<thread id="p2141.214f" core="1"/>\n<thread id="p2141.2150" core="2"/>\n</threads>\n
Becomes:
Sending packet: $qXfer:threads:read::0,fff#03...Packet received: l<threads>\n<thread id="p2141.2141" core="2"/>\n<thread id="p2141.214f" core="1"/>\n<thread id="p2141.2150" core="2"/>\n</threads>\n
Tested on x86_64 Fedora 20, native gdbserver:
- tests the qXfer:threads:read method.
Tested on x86_64 Fedora 20, native gdbserver with qXfer:threads:read
force-disabled in gdbserver:
- So that GDB falls back to the qfThreadInfo/qsThreadInfo method.
And also manually smoked tested force disabling both
qXfer:threads:read and qfThreadInfo/qsThreadInfo in gdbserver.
gdb/
2014-10-15 Pedro Alves <palves@redhat.com>
* gdbthread.h (ALL_NON_EXITED_THREADS_SAFE): New macro.
* remote.c (remote_update_thread_list): Skip calling prune_threads
if any thread listing method is supported, and instead walk over
the set of remote threads listed, deleting those that are not
found in GDB's thread list.
When GDB wants to sync the thread list with the target's (e.g., due to
"info threads"), it calls update_thread_list:
update_thread_list (void)
{
prune_threads ();
target_find_new_threads ();
update_threads_executing ();
}
And then prune_threads does:
prune_threads (void)
{
struct thread_info *tp, *next;
for (tp = thread_list; tp; tp = next)
{
next = tp->next;
if (!thread_alive (tp))
delete_thread (tp->ptid);
}
}
Calling thread_live on each thread one by one is expensive.
E.g., on Linux, it ends up doing kill(SIG0) once for each thread. Not
a big deal, but still a bunch of syscalls...
With the remote target, it's cumbersome. That thread_alive call ends
up generating one T packet per thread:
Sending packet: $Tp2141.2150#82...Packet received: OK
Sending packet: $Tp2141.214f#b7...Packet received: OK
Sending packet: $Tp2141.2141#82...Packet received: OK
Sending packet: $qXfer:threads:read::0,fff#03...Packet received: l<threads>\n<thread id="p2141.2141" core="2"/>\n<thread id="p2141.214f" core="1"/>\n<thread id="p2141.2150" core="2"/>\n</threads>\n
That seems a bit silly when target_find_new_threads method
implementations will always fetch the whole current set of target
threads, and then add those that are not in GDB's thread list, to
GDB's thread list.
This patch thus pushes down the responsibility of pruning dead threads
to the target_find_new_threads method instead, so a target may
implement pruning dead threads however it wants.
Once we do that, target_find_new_threads becomes a misnomer, so the
patch renames it to target_update_thread_list.
The patch doesn't attempt to do any optimization to any target yet.
It simply exports prune_threads, and makes all implementations of
target_update_thread_list call that. It's meant to be a no-op.
gdb/
2014-10-15 Pedro Alves <palves@redhat.com>
* ada-tasks.c (print_ada_task_info, task_command_1): Adjust.
* bsd-uthread.c (bsd_uthread_find_new_threads): Rename to ...
(bsd_uthread_update_thread_list): ... this. Call prune_threads.
(bsd_uthread_target): Adjust.
* corelow.c (core_open): Adjust.
* dec-thread.c (dec_thread_find_new_threads): Update comment.
(dec_thread_update_thread_list): New function.
(init_dec_thread_ops): Adjust.
* gdbthread.h (prune_threads): New declaration.
* linux-thread-db.c (thread_db_find_new_threads): Rename to ...
(thread_db_update_thread_list): ... this. Call prune_threads.
(init_thread_db_ops): Adjust.
* nto-procfs.c (procfs_find_new_threads): Rename to ...
(procfs_update_thread_list): ... this. Call prune_threads.
(procfs_attach, procfs_create_inferior, init_procfs_targets):
Adjust.
* obsd-nat.c (obsd_find_new_threads): Rename to ...
(obsd_update_thread_list): ... this. Call prune_threads.
(obsd_add_target): Adjust.
* procfs.c (procfs_target): Adjust.
(procfs_notice_thread): Update comment.
(procfs_find_new_threads): Rename to ...
(procfs_update_thread_list): ... this. Call prune_threads.
* ravenscar-thread.c (ravenscar_update_inferior_ptid): Update
comment.
(ravenscar_wait): Adjust.
(ravenscar_find_new_threads): Rename to ...
(ravenscar_update_thread_list): ... this. Call prune_threads.
(init_ravenscar_thread_ops): Adjust.
* record-btrace.c (record_btrace_find_new_threads): Rename to ...
(record_btrace_update_thread_list): ... this. Adjust comment.
(init_record_btrace_ops): Adjust.
* remote.c (remote_threads_info): Rename to ...
(remote_update_thread_list): ... this. Call prune_threads.
(remote_start_remote, extended_remote_attach_1, init_remote_ops):
Adjust.
* sol-thread.c (check_for_thread_db): Adjust.
(sol_find_new_threads_callback): Rename to ...
(sol_update_thread_list_callback): ... this.
(sol_find_new_threads): Rename to ...
(sol_update_thread_list): ... this. Call prune_threads. Adjust.
(sol_get_ada_task_ptid, init_sol_thread_ops): Adjust.
* target-delegates.c: Regenerate.
* target.c (target_find_new_threads): Rename to ...
(target_update_thread_list): ... this.
* target.h (struct target_ops): Rename to_find_new_threads field
to to_update_thread_list.
(target_find_new_threads): Rename to ...
(target_update_thread_list): ... this.
* thread.c (prune_threads): Make extern.
(update_thread_list): Adjust.
We have three methods to list the current remote thread list:
1. The qXfer:threads:read method (the preferred one nowadays), builds a
remote thread list while parsing the XML, and then after the XML
parsing is done, goes over the built list and adds threads GDB doesn't
know about yet to GDB's list.
2. If the qXfer method isn't available, we fallback to using the
qfThreadInfo/qsThreadInfo packets. When we do this, we adds threads
to GDB's list immediately as we parse the qfThreadInfo/qsThreadInfo
packet replies.
3. And then if the previous method isn't available either, we try the
old deprecated qL packet. This path is already looking somewhat
broken for not using remote_notice_new_inferior to add threads to
GDB's list.
This patch makes all variants work in two passes, like the qXfer
method, and then makes all variants share the code path that adds
threads to GDB's list.
Tested on x86_64 Fedora 20 with native gdbserver.
gdb/
2014-10-15 Pedro Alves <palves@redhat.com>
* remote.c (remote_get_threadlist, remote_threadlist_iterator):
Add describing comment. Return -1 if the qL packet is not
supported.
(struct thread_item, thread_item_t): Move higher up in
the file. Add comments.
(struct threads_parsing_context): Move higher up in
the file, add comments, and remote to ...
(struct threads_listing_context): ... this.
(remote_newthread_step): Don't add the thread to GDB's thread
database here. Instead push it to the thread_listing_context
list.
(remote_find_new_threads): Rename to ...
(remote_get_threads_with_ql): ... this. Add target_ops and
targets_listing_context parameters. Pass down context.
(start_thread): Adjust.
(clear_threads_parsing_context): Rename to ...
(clear_threads_listing_context): ... this.
(remote_get_threads_with_qxfer): New, with parts salvaged from old
remote_threads_info.
(remote_get_threads_with_qthreadinfo): Ditto.
(remote_threads_info): Reimplement.
This change:
commit b775012e84
Author: Luis Machado <luisgpm@br.ibm.com>
Date: Fri Feb 24 15:10:59 2012 +0000
2012-02-24 Luis Machado <lgustavo@codesourcery.com>
* remote.c (remote_supports_cond_breakpoints): New forward
declaration.
[...]
changed the way breakpoints are inserted and removed such that
`insert_bp_location' can now be called with the breakpoint being handled
already in place, while previously the call was only ever made for
breakpoints that have not been put in place. This in turn caused an
issue for software breakpoints and targets for which a breakpoint's
`placed_address' may not be the same as the original requested address.
The issue is `insert_bp_location' overwrites the previously adjusted
value in `placed_address' with the original address, that is only
replaced back with the correct adjusted address later on when
`gdbarch_breakpoint_from_pc' is called. Meanwhile there's a window
where the value in `placed_address' does not correspond to data stored
in `shadow_contents', leading to incorrect instruction bytes being
supplied when `one_breakpoint_xfer_memory' is called to supply the
instruction overlaid by the breakpoint.
And this is exactly what happens on the MIPS target with software
breakpoints placed in microMIPS code. In this case not only
`placed_address' is not the original address because of the ISA bit, but
`mips_breakpoint_from_pc' has to read the original instruction to
determine which one of the two software breakpoint instruction encodings
to choose as well. The 16-bit encoding is used to replace 16-bit
instructions and similarly the 32-bit one is used with 32-bit
instructions, to satisfy branch delay slot size requirements.
The mismatch between `placed_address' and the address data in
`shadow_contents' has been obtained from leads to the wrong encoding
being used in some cases, which in the case of a 32-bit software
breakpoint instruction replacing a 16-bit instruction causes corruption
to the adjacent following instruction and leads the debug session astray
if execution reaches there e.g. with a jump.
To address this problem I made the change below, that adds a
`reqstd_address' field to `struct bp_target_info' and leaves
`placed_address' unchanged once it has been set. This ensures data in
`shadow_contents' is always consistent with `placed_address'.
This approach also has this good side effect that all the places that
examine the breakpoint's address see a consistent value, either
`reqstd_address' or `placed_address', as required. Currently some
places see either the original or the adjusted address in
`placed_address', depending on whether they have been called before
`gdbarch_remote_breakpoint_from_pc' or afterwards. This is in
particular true for subsequent calls to
`gdbarch_remote_breakpoint_from_pc' itself, e.g. from
`one_breakpoint_xfer_memory'. This is also important for places like
`find_single_step_breakpoint' where a breakpoint's address is compared
to the raw value of $pc.
* breakpoint.h (bp_target_info): Add `reqstd_address' member,
update comments.
* breakpoint.c (one_breakpoint_xfer_memory): Use `reqstd_address'
for the breakpoint's address. Don't preinitialize `placed_size'.
(insert_bp_location): Set `reqstd_address' rather than
`placed_address'.
(bp_target_info_copy_insertion_state): Also copy `placed_address'.
(bkpt_insert_location): Use `reqstd_address' for the breakpoint's
address.
(bkpt_remove_location): Likewise.
(deprecated_insert_raw_breakpoint): Likewise.
(deprecated_remove_raw_breakpoint): Likewise.
(find_single_step_breakpoint): Likewise.
* mem-break.c (default_memory_insert_breakpoint): Use
`reqstd_address' for the breakpoint's address. Don't set
`placed_address' or `placed_size' if breakpoint contents couldn't
have been determined.
* remote.c (remote_insert_breakpoint): Use `reqstd_address' for
the breakpoint's address.
(remote_insert_hw_breakpoint): Likewise. Don't set
`placed_address' or `placed_size' if breakpoint couldn't have been
set.
* aarch64-linux-nat.c (aarch64_linux_insert_hw_breakpoint): Use
`reqstd_address' for the breakpoint's address.
* arm-linux-nat.c (arm_linux_hw_breakpoint_initialize): Likewise.
* ia64-tdep.c (ia64_memory_insert_breakpoint): Likewise.
* m32r-tdep.c (m32r_memory_insert_breakpoint): Likewise.
* microblaze-linux-tdep.c
(microblaze_linux_memory_remove_breakpoint): Likewise.
* monitor.c (monitor_insert_breakpoint): Likewise.
* nto-procfs.c (procfs_insert_breakpoint): Likewise.
(procfs_insert_hw_breakpoint): Likewise.
* ppc-linux-nat.c (ppc_linux_insert_hw_breakpoint): Likewise.
* ppc-linux-tdep.c (ppc_linux_memory_remove_breakpoint): Likewise.
* remote-m32r-sdi.c (m32r_insert_breakpoint): Likewise.
* remote-mips.c (mips_insert_breakpoint): Likewise.
* x86-nat.c (x86_insert_hw_breakpoint): Likewise.
By default, GDB removes all breakpoints from the target when the
target stops and the prompt is given back to the user. This is useful
in case GDB crashes while the user is interacting, as otherwise,
there's a higher chance breakpoints would be left planted on the
target.
But, as long as any thread is running free, we need to make sure to
keep breakpoints inserted, lest a thread misses a breakpoint. With
that in mind, in preparation for non-stop mode, we added a "breakpoint
always-inserted on" mode. This traded off the extra crash protection
for never having threads miss breakpoints, and in addition is more
efficient if there's a ton of breakpoints to remove/insert at each
user command (e.g., at each "step").
When we added non-stop mode, and for a period, we required users to
manually set "always-inserted on" when they enabled non-stop mode, as
otherwise GDB removes all breakpoints from the target as soon as any
thread stops, which means the other threads still running will miss
breakpoints. The test added by this patch exercises this.
That soon revealed a nuisance, and so later we added an extra
"breakpoint always-inserted auto" mode, that made GDB behave like
"always-inserted on" when non-stop was enabled, and "always-inserted
off" when non-stop was disabled. "auto" was made the default at the
same time.
In hindsight, this "auto" setting was unnecessary, and not the ideal
solution. Non-stop mode does depends on breakpoints always-inserted
mode, but only as long as any thread is running. If no thread is
running, no breakpoint can be missed. The same is true for all-stop
too. E.g., if, in all-stop mode, and the user does:
(gdb) c&
(gdb) b foo
That breakpoint at "foo" should be inserted immediately, but it
currently isn't -- currently it'll end up inserted only if the target
happens to trip on some event, and is re-resumed, e.g., an internal
breakpoint triggers that doesn't cause a user-visible stop, and so we
end up in keep_going calling insert_breakpoints. The test added by
this patch also covers this.
IOW, no matter whether in non-stop or all-stop, if the target fully
stops, we can remove breakpoints. And no matter whether in all-stop
or non-stop, if any thread is running in the target, then we need
breakpoints to be immediately inserted. And then, if the target has
global breakpoints, we need to keep breakpoints even when the target
is stopped.
So with that in mind, and aiming at reducing all-stop vs non-stop
differences for all-stop-on-stop-of-non-stop, this patch fixes
"breakpoint always-inserted off" to not remove breakpoints from the
target until it fully stops, and then removes the "auto" setting as
unnecessary. I propose removing it straight away rather than keeping
it as an alias, unless someone complains they have scripts that need
it and that can't adjust.
Tested on x86_64 Fedora 20.
gdb/
2014-09-22 Pedro Alves <palves@redhat.com>
* NEWS: Mention merge of "breakpoint always-inserted" modes "off"
and "auto" merged.
* breakpoint.c (enum ugll_insert_mode): New enum.
(always_inserted_mode): Now a plain boolean.
(show_always_inserted_mode): No longer handle AUTO_BOOLEAN_AUTO.
(breakpoints_always_inserted_mode): Delete.
(breakpoints_should_be_inserted_now): New function.
(insert_breakpoints): Pass UGLL_INSERT to
update_global_location_list instead of calling
insert_breakpoint_locations manually.
(create_solib_event_breakpoint_1): New, factored out from ...
(create_solib_event_breakpoint): ... this.
(create_and_insert_solib_event_breakpoint): Use
create_solib_event_breakpoint_1 instead of calling
insert_breakpoint_locations manually.
(update_global_location_list): Change parameter type from boolean
to enum ugll_insert_mode. All callers adjusted. Adjust to use
breakpoints_should_be_inserted_now and handle UGLL_INSERT.
(update_global_location_list_nothrow): Change parameter type from
boolean to enum ugll_insert_mode.
(_initialize_breakpoint): "breakpoint always-inserted" option is
now a boolean command. Update help text.
* breakpoint.h (breakpoints_always_inserted_mode): Delete declaration.
(breakpoints_should_be_inserted_now): New declaration.
* infrun.c (handle_inferior_event) <TARGET_WAITKIND_LOADED>:
Remove breakpoints_always_inserted_mode check.
(normal_stop): Adjust to use breakpoints_should_be_inserted_now.
* remote.c (remote_start_remote): Likewise.
gdb/doc/
2014-09-22 Pedro Alves <palves@redhat.com>
* gdb.texinfo (Set Breaks): Document that "set breakpoint
always-inserted off" is the default mode now. Delete
documentation of "set breakpoint always-inserted auto".
gdb/testsuite/
2014-09-22 Pedro Alves <palves@redhat.com>
* gdb.threads/break-while-running.exp: New file.
* gdb.threads/break-while-running.c: New file.
The code becomes dead as GDB evolves. In 2003, Andrew Cagney post patch
https://sourceware.org/ml/gdb-patches/2003-10/msg00511.html to add target
read/write partial methods. They support query buffer size when both
OFFSET and LEN is zero, and it was used in avr-tdep.c and kod.c. Then,
Daniel added target_read_object_alloc and avr-tdep.c switches to use that
in patch https://sourceware.org/ml/gdb-patches/2006-07/msg00009.html
From then on, GDB on longer queries the buffer size, so the code
returning packet size in remote_xfer_partial became dead.
PR 17060 is duplicated of PR 9053, so I mention the latter in the
ChangeLog entry. Rebuild GDB with this patch. OK to apply?
I'll mark PR 17060 as duplicated once the patch is applied.
gdb:
2014-08-09 Yao Qi <yao@codesourcery.com>
PR remote/9053
* remote.c (remote_xfer_partial): Remove dead code.
I run splint in gdb source and get the following warnings:
../../../git/gdb/corelow.c:740: Return value type int does not match declared type enum target_xfer_status: 0
'TARGET_XFER_EOF' (enum target_xfer_status) is expected to be returned,
but 0 is returned. This patch is to replace 0 with TARGET_XFER_EOF
in the implementations of to_xfer_partial.
gdb:
2014-08-07 Yao Qi <yao@codesourcery.com>
* corelow.c (core_xfer_partial): Replace 0 with TARGET_XFER_EOF.
* remote-m32r-sdi.c (m32r_xfer_memory): Likewise.
* remote.c (remote_read_bytes): Likewise.
This makes target_ops::to_open take a const string and then fixes the
fallout.
There were a few of these I could not build. However I eyeballed it
and in any case the fixes should generally be trivial.
This is based on the patch to fix up the target debugging for to_open,
because that changes gdb to not directly install to_open as the target
command
2014-07-30 Tom Tromey <tromey@redhat.com>
* bsd-kvm.c (bsd_kvm_open): Constify.
* corelow.c (core_open): Constify.
* ctf.c (ctf_open): Constify.
* dbug-rom.c (dbug_open): Constify.
* exec.c (exec_open): Constify.
* m32r-rom.c (m32r_open, mon2000_open): Constify.
* microblaze-rom.c (picobug_open): Constify.
* nto-procfs.c (procfs_open_1, procfs_open, procfs_native_open):
Constify.
* ppcbug-rom.c (ppcbug_open0, ppcbug_open1): Constify.
* record-btrace.c (record_btrace_open): Constify.
* record-full.c (record_full_core_open_1, record_full_open_1)
(record_full_open): Constify.
* remote-m32r-sdi.c (m32r_open): Constify.
* remote-mips.c (common_open, mips_open, pmon_open, ddb_open)
(rockhopper_open, lsi_open): Constify.
* remote-sim.c (gdbsim_open): Constify.
* remote.c (remote_open, extended_remote_open, remote_open_1):
Constify.
* target.h (struct target_ops) <to_open>: Make "arg" const.
* tracefile-tfile.c (tfile_open): Constify.
Currently, GDB can pass a signal to the wrong thread in several
different but related scenarios.
E.g., if thread 1 stops for signal SIGFOO, the user switches to thread
2, and then issues "continue", SIGFOO is actually delivered to thread
2, not thread 1. This obviously messes up programs that use
pthread_kill to send signals to specific threads.
This has been a known issue for a long while. Back in 2008 when I
made stop_signal be per-thread (2020b7ab), I kept the behavior -- see
code in 'proceed' being removed -- wanting to come back to it later.
The time has finally come now.
The patch fixes this -- on resumption, intercepted signals are always
delivered to the thread that had intercepted them.
Another example: if thread 1 stops for a breakpoint, the user switches
to thread 2, and then issues "signal SIGFOO", SIGFOO is actually
delivered to thread 1, not thread 2, because 'proceed' first switches
to thread 1 to step over its breakpoint... If the user deletes the
breakpoint before issuing "signal FOO", then the signal is delivered
to thread 2 (the current thread).
"signal SIGFOO" can be used for two things: inject a signal in the
program while the program/thread had stopped for none, bypassing
"handle nopass"; or changing/suppressing a signal the program had
stopped for. These scenarios are really two faces of the same coin,
and GDB can't really guess what the user is trying to do. GDB might
have intercepted signals in more than one thread even (see the new
signal-command-multiple-signals-pending.exp test). At least in the
inject case, it's obviously clear to me that the user means to deliver
the signal to the currently selected thread, so best is to make the
command's behavior consistent and easy to explain.
Then, if the user is trying to suppress/change a signal the program
had stopped for instead of injecting a new signal, but, the user had
changed threads meanwhile, then she will be surprised that with:
(gdb) continue
Thread 1 stopped for signal SIGFOO.
(gdb) thread 2
(gdb) signal SIGBAR
... GDB actually delivers SIGFOO to thread 1, and SIGBAR to thread 2
(with scheduler-locking off, which is the default, because then
"signal" or any other resumption command resumes all threads).
So the patch makes GDB detect that, and ask for confirmation:
(gdb) thread 1
[Switching to thread 1 (Thread 10979)]
(gdb) signal SIGUSR2
Note:
Thread 3 previously stopped with signal SIGUSR2, User defined signal 2.
Thread 2 previously stopped with signal SIGUSR1, User defined signal 1.
Continuing thread 1 (the current thread) with specified signal will
still deliver the signals noted above to their respective threads.
Continue anyway? (y or n)
All these scenarios are covered by the new tests.
Tested on x86_64 Fedora 20, native and gdbserver.
gdb/
2014-07-25 Pedro Alves <palves@redhat.com>
* NEWS: Mention signal passing and "signal" command changes.
* gdbthread.h (struct thread_suspend_state) <stop_signal>: Extend
comment.
* breakpoint.c (until_break_command): Adjust clear_proceed_status
call.
* infcall.c (run_inferior_call): Adjust clear_proceed_status call.
* infcmd.c (proceed_thread_callback, continue_1, step_once)
(jump_command): Adjust clear_proceed_status call.
(signal_command): Warn if other thread that are resumed have
signals that will be delivered. Adjust clear_proceed_status call.
(until_next_command, finish_command)
(proceed_after_attach_callback, attach_command_post_wait)
(attach_command): Adjust clear_proceed_status call.
* infrun.c (proceed_after_vfork_done): Likewise.
(proceed_after_attach_callback): Adjust comment.
(clear_proceed_status_thread): Clear stop_signal if not in pass
state.
(clear_proceed_status_callback): Delete.
(clear_proceed_status): New 'step' parameter. Only clear the
proceed status of threads the command being prepared is about to
resume.
(proceed): If passed in an explicit signal, override stop_signal
with it. Don't pass the last stop signal to the thread we're
resuming.
(init_wait_for_inferior): Adjust clear_proceed_status call.
(switch_back_to_stepped_thread): Clear the signal if it should not
be passed.
* infrun.h (clear_proceed_status): New 'step' parameter.
(user_visible_resume_ptid): Add comment.
* linux-nat.c (linux_nat_resume_callback): Don't check whether the
signal is in pass state.
* remote.c (append_pending_thread_resumptions): Likewise.
* mi/mi-main.c (proceed_thread): Adjust clear_proceed_status call.
gdb/doc/
2014-07-25 Pedro Alves <palves@redhat.com>
Eli Zaretskii <eliz@gnu.org>
* gdb.texinfo (Signaling) <signal command>: Explain what happens
with multi-threaded programs.
gdb/testsuite/
2014-07-25 Pedro Alves <palves@redhat.com>
* gdb.threads/signal-command-handle-nopass.c: New file.
* gdb.threads/signal-command-handle-nopass.exp: New file.
* gdb.threads/signal-command-multiple-signals-pending.c: New file.
* gdb.threads/signal-command-multiple-signals-pending.exp: New file.
* gdb.threads/signal-delivered-right-thread.c: New file.
* gdb.threads/signal-delivered-right-thread.exp: New file.
This does some more constification in remote.c.
2014-07-24 Tom Tromey <tromey@redhat.com>
* remote.c (remote_serial_open, print_packet, putpkt)
(putpkt_binary): Constify.
* remote.h (putpkt): Update.
When debugging a remote bare-metal target with "target
extended-remote" + attach, GDB won't send a qSymbol packet to initiate
symbol lookup. This happens because all the previous places in which
GDB might have done this are guarded by conditions that don't hold in
the said scenario: there are no shared libraries, no vsyscall page and
the binary file didn't change in the time passed between the "file"
and the "attach" commands.
To solve this problem remote_check_symbols is called in the
target_post_attach hook.
gdb/
2014-07-11 Adrian Sendroiu <adrian.sendroiu@freescale.com>
* remote.c (extended_remote_post_attach): New function.
(init_extended_remote_ops): Install it as to_post_attach method.
On Windows, with "maint set target-async on" (the default since
a09dd441), Ctrl-C fails to stop a remote target.
With maint target-async on, the SIGINT signal handler doesn't send the
remote interrupt request immediately. Instead, it marks an async
handler as ready, and then the main event loop wakes up and notices
that the SIGINT async signal handler token was set, and calls the
corresponding event handler, which sends the remote interrupt request.
On POSIX-like systems, the SIGINT signal makes the select/poll in the
main event loop wake up / return with EINTR. However, on Windows,
signal handlers run on a separate thread, and Windows doesn't really
have a concept of EINTR. So, just marking the async handler
(effectively just setting a flag) does not wake up gdb_select.
Instead, we need to call gdb_call_async_signal_handler from the signal
handler. The Windows version (in mingw-hdep.c) sets a Windows event
that gdb_select's WaitForMultipleObjects is waiting for.
Confirmed that with this, Ctrl-C interrupts the remote target on
Windows. Also regression tested on x86_64 Fedora 20 against
GDBserver.
gdb/
2014-07-07 Pedro Alves <palves@redhat.com>
* remote.c (async_handle_remote_sigint)
(async_handle_remote_sigint_twice): Call
gdb_call_async_signal_handler instead of
mark_async_signal_handler.
This makes the argument to the target_ops to_load method "const", and
fixes up the fallout. Tested by rebuilding all the affected files.
2014-06-26 Tom Tromey <tromey@redhat.com>
* defs.h (generic_load): Update.
* m32r-rom.c (m32r_load_gen): Make "filename" const.
* monitor.c (monitor_load): Make "args" const.
* remote-m32r-sdi.c (m32r_load): Make "args" const.
* remote-mips.c (mips_load_srec, pmon_load_fast): Make "args"
const.
(mips_load): Make "file" const.
* remote-sim.c (gdbsim_load): Make "args" const.
* remote.c (remote_load): Make "name" const.
* symfile.c (generic_load): Make "args" const.
* target-delegates.c: Rebuild.
* target.c (target_load): Make "arg" const.
(debug_to_load): Make "args" const.
* target.h (struct target_ops) <to_load>: Make parameter const.
(target_load): Update.
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.
This replaces a function cast with a call to make_cleanup_freeargv.
I'm checking this in as obvious.
2014-06-17 Tom Tromey <tromey@redhat.com>
* remote.c (extended_remote_run): Use make_cleanup_freeargv.
Currently there are many calls to help_list that pass the constant -1
as the "class" value. However, the parameter is declared as being of
type enum command_class, and uses of the constant violate this
abstraction.
This patch fixes the error everywhere it occurs in the gdb sources.
Tested by rebuilding.
2014-06-13 Tom Tromey <tromey@redhat.com>
* cp-support.c (maint_cplus_command): Pass all_commands, not -1,
to help_list.
* guile/guile.c (info_guile_command): Pass all_commands, not -1,
to help_list.
* tui/tui-win.c (tui_command): Pass all_commands, not -1, to
help_list.
* tui/tui-regs.c (tui_reg_command): Pass all_commands, not -1, to
help_list.Pass all_commands, not -1, to help_list.
* cli/cli-dump.c (dump_command, append_command)
(srec_dump_command, ihex_dump_command, tekhex_dump_command)
(binary_dump_command, binary_append_command): Pass all_commands,
not -1, to help_list.
* cli/cli-cmds.c (info_command, set_debug): Pass all_commands, not
-1, to help_list.
* valprint.c (set_print, set_print_raw): Pass all_commands, not
-1, to help_list.
* typeprint.c (set_print_type): Pass all_commands, not -1, to
help_list.
* top.c (set_history): Pass all_commands, not -1, to help_list.
* target-descriptions.c (set_tdesc_cmd, unset_tdesc_cmd): Pass
all_commands, not -1, to help_list.
* symfile.c (overlay_command): Pass all_commands, not -1, to
help_list.
* spu-tdep.c (info_spu_command): Pass all_commands, not -1, to
help_list.
* serial.c (serial_set_cmd): Pass all_commands, not -1, to
help_list.
* ser-tcp.c (set_tcp_cmd, show_tcp_cmd): Pass all_commands, not
-1, to help_list.
* remote.c (remote_command, set_remote_cmd): Pass all_commands,
not -1, to help_list.
* ravenscar-thread.c (set_ravenscar_command): Pass all_commands,
not -1, to help_list.
* maint.c (maintenance_command, maintenance_info_command)
(maintenance_print_command, maintenance_set_cmd): Pass
all_commands, not -1, to help_list.
* macrocmd.c (macro_command): Pass all_commands, not -1, to
help_list.
* language.c (set_check): Pass all_commands, not -1, to help_list.
* infcmd.c (unset_command): Pass all_commands, not -1, to
help_list.
* frame.c (set_backtrace_cmd): Pass all_commands, not -1, to
help_list.
* dwarf2read.c (set_dwarf2_cmd): Pass all_commands, not -1, to
help_list.
* dcache.c (set_dcache_command): Pass all_commands, not -1, to
help_list.
* breakpoint.c (save_command): Pass all_commands, not -1, to
help_list.
* ada-lang.c (maint_set_ada_cmd, set_ada_command): Pass
all_commands, not -1, to help_list.
Original patch:
https://sourceware.org/ml/gdb-patches/2014-04/msg00552.html
New in v2:
* In remote.c:escape_buffer, pass '\\' to fputstrn_unfiltered/printchar to
make sure backslashes are escaped in remote debug output.
* Updated function documentation for printchar.
See updated ChangeLog below.
--------------------
The quoting in whatever goes in the event_channel of MI is little bit broken.
Link for the lazy:
https://sourceware.org/bugzilla/show_bug.cgi?id=15806
Here is an example of a =library-loaded event with an ill-named directory,
/tmp/how"are\you (the problem is present with every directory on Windows since
it uses backslashes as a path separator). The result will be the following:
=library-loaded,id="/tmp/how"are\\you/libexpat.so.1",...
The " between 'how' and 'are' should be escaped.
Another bad behavior is double escaping in =breakpoint-created, for example:
=breakpoint-created,bkpt={...,fullname="/tmp/how\\"are\\\\you/test.c",...}
The two backslashes before 'how' should be one and the four before 'you' should
be two.
The reason for this is that when sending something to an MI console, escaping
can take place at two different moments (the actual escaping work is always
done in the printchar function):
1. When generating the content, if ui_out_field_* functions are used. Here,
fields are automatically quoted with " and properly escaped. At least
mi_field_string does it, not sure about mi_field_fmt, I need to investigate
further.
2. When gdb_flush is called, to send the data in the buffer of the console to
the actual output (stdout). At this point, mi_console_raw_packet takes the
whole string in the buffer, quotes it, and escapes all occurences of the
quoting character and backslashes. The event_channel does not specify a quoting
character, so quotes are not escaped here, only backslashes.
The problem with =library-loaded is that it does use fprintf_unfiltered, which
doesn't do escaping (so, no #1). When gdb_flush is called, backslashes are
escaped (#2).
The problem with =breakpoint-created is that it first uses ui_out_field_*
functions to generate its output, so backslashes and quotes are escaped there
(#1). backslashes are escaped again in #2, leading to an overdose of
backslashes.
In retrospect, there is no way escaping can be done reliably in
mi_console_raw_packet for data that is already formatted, such as
event_channel. At this point, there is no way to differentiate quotes that
delimit field values from those that should be escaped. In the case of other MI
consoles, it is ok since mi_console_raw_packet receives one big string that
should be quoted and escaped as a whole.
So, first part of the fix: for the MI channels that specify no quoting
character, no escaping at all should be done in mi_console_raw_packet (that's
the change in printchar, thanks to Yuanhui Zhang for this). For those channels,
whoever generates the content is responsible for proper quoting and escaping.
This will fix the =breakpoint-created kind of problem.
Second part of the fix is to make =library-loaded generate content that is
properly escaped. For this, we use ui_out_field_* functions, instead of one big
fprintf_unfiltered. =library-unloaded suffered from the same problem so it is
modified as well. There might be other events that need fixing too, but that's
all I found with a quick scan. Those that use fprintf_unfiltered but whose sole
variable data is a %d are not critical, since it won't generate a " or a \.
Finally, a test has been fixed, as it was expecting an erroneous output.
Otherwise, all other tests that were previously passing still pass (x86-64
linux).
gdb/ChangeLog:
2014-06-02 Simon Marchi <simon.marchi@ericsson.com>
PR mi/15806
* utils.c (printchar): Don't escape at all if quoter is NUL.
Update function documentation to clarify effect of parameter
QUOTER.
* remote.c (escape_buffer): Pass '\\' as the quoter to
fputstrn_unfiltered.
* mi/mi-interp.c (mi_solib_loaded): Use ui_out_field_* functions to
generate the output.
(mi_solib_unloaded): Same.
gdb/testsuite/ChangeLog:
2014-06-02 Simon Marchi <simon.marchi@ericsson.com>
* gdb.mi/mi-breakpoint-changed.exp (test_insert_delete_modify): Fix
erroneous dprintf expected input.
This constifies the "args" argument to the target_ops to_attach
method.
I updated all instances of the method. I could not compile all of
them but I hand-inspected them. In all cases either the argument is
ignored, or it is passed to parse_pid_to_attach. (linux-nat does some
extra stuff, but that one I built...)
If you want to try it on your host of choice, please do so.
The code in parse_pid_to_attach seems a little bogus to me. If there
is a platform with a broken strtoul, we have better methods for fixing
the issue now. However, I left the code as is since it is clearly ok
to do so.
Built and regtested on x86-64 Fedora 20.
2014-06-04 Tom Tromey <tromey@redhat.com>
* procfs.c (procfs_attach): Make "args" const.
* windows-nat.c (windows_attach): Make "args" const.
* nto-procfs.c (procfs_attach): Make "args" const.
* inf-ttrace.c (inf_ttrace_attach): Make "args" const.
* go32-nat.c (go32_attach): Make "args" const.
* gnu-nat.c (gnu_attach): Make "args" const.
* darwin-nat.c (darwin_attach): Make "args" const.
* inf-ptrace.c (inf_ptrace_attach): Make "args" const.
* linux-nat.c (linux_nat_attach): Make "args" const.
* remote.c (extended_remote_attach_1, extended_remote_attach):
Make "args" const.
* target.h (struct target_ops) <to_attach>: Make "args" const.
(find_default_attach): Likewise.
* utils.c (parse_pid_to_attach): Make "args" const.
* utils.h (parse_pid_to_attach): Update.
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.
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.
When connecting to a remote system, we use the compare-sections
command to verify that the box is running the code that we think it is
running. Since the system is up and running and *NOT* 'freshly
downloaded without yet executing anything', read-write sections, of
course, differ from what they were in the executable file.
Comparing read-write sections takes time and more importantly the
MIS-MATCHED output is confusing to some users.
The compare-sections command compares all loadable sections including
read-write sections. This patch gives the user the option to compare
just the loadable read-only sections.
gdb/
2014-05-01 David Taylor <dtaylor@emc.com>
* remote.c (compare_sections_command): Add -r option to compare
all loadable read-only sections.
gdb/doc/
2014-05-01 David Taylor <dtaylor@emc.com>
* gdb.texinfo (compare-sections): Document the new -r (read-only)
option.
... and others. The recent patch that fixed several "set remote
foo-packet on/off" commands introduced a regression, observable when
connecting GDB to QEMU. For instance:
(gdb) set debug remote 1
(gdb) tar rem :4444
Remote debugging using :4444
Sending packet: $qSupported:multiprocess+;qRelocInsn+#2a...Ack
Packet received: PacketSize=1000;qXfer:features:read+
Packet qSupported (supported-packets) is supported
Sending packet: $Hgp0.0#ad...Ack
Packet received: OK
Sending packet: $qXfer:features:read:target.xml:0,ffb#79...Ack
Packet received: [...]
Sending packet: $qXfer:features:read:arm-core.xml:0,ffb#08...Ack
Packet received: [...]
!!! -> Sending packet: $QNonStop:0#8c...Ack
Packet received:
Remote refused setting all-stop mode with:
The "QNonStop" feature is associated with the PACKET_QNonStop packet,
with a default of PACKET_DISABLE, so GDB should not be sending the
packet at all.
The patch that introduced the regression decoupled packet_config's
'detect' and 'support' fields, making the former (an auto_boolean)
purely the associated "set remote foo-packet" command's variable. In
the example above, the packet config's 'supported' field does end up
correctly set to PACKET_DISABLE. However, nothing is presently
initializing packet configs that don't actually have a command
associated. Those configs's 'detect' field then ends up set to
AUTO_BOOLEAN_TRUE, simply because that happens to be 0. This forces
GDB to assume the packet is supported, irrespective of what the target
claims it supports, just like if the user had done "set remote
foo-packet on" (this being the associated command, if there was one).
Ideally, all packet configs would have a command associated. While
that isn't true, make sure all packet configs are initialized, even if
no command is associated, and add an assertion that prevents adding
more packets/features without an associated command.
Tested on x86_64 Fedora 17, against pristine gdbserver, and against a
gdbserver with the QNonStop packet/feature disabled with a local hack.
gdb/
2014-04-29 Pedro Alves <palves@redhat.com>
* remote.c (struct packet_config) <detect>: Extend comment.
(add_packet_config_cmd): Don't set the config's detect or support
fields here.
(init_all_packet_configs): Also initialize the config's 'detect'
field.
(reset_all_packet_configs_support): New function.
(remote_open_1): Call reset_all_packet_configs_support instead of
init_all_packet_configs.
(_initialize_remote): Initialize all packet configs. Assert that
all packets have an associated command, except a few known
outliers.
For several RSP packets, there's a corresponding "set remote
foo-packet on/off/auto" command that one can use do bypass
auto-detection of support for the packet or feature. However, I
noticed that setting several of these commands to 'on' or 'off'
doesn't actually have any effect. These are, at least:
set remote breakpoint-commands-packet
set remote conditional-breakpoints-packet
set remote fast-tracepoints-packet
set remote static-tracepoints-packet
set remote install-in-trace-packet
These are commands that control a remote protocol feature that doesn't
have a corresponding regular packet, and because of that we cache the
knowledge of the remote side support as returned by the qSupported
packet in the remote_state object.
E.g., in the case of the 'set remote breakpoint-commands-packet'
command, whether the feature is supported is recorded in the
'breakpoint_commands' field of the remote_state object.
Whether to bypass packet support auto-detection or not is controlled
by the 'detect' field of the corresponding packet's packet_config
structure. That field is the variable associated directly with the
"set remote foo-packet" command. Actual remote stub support for the
packet (or feature) is recorded in the 'support' field of the same
structure.
However, when the user toggles the command, the 'support' field is
also correspondingly updated to PACKET_ENABLE/DISABLE/SUPPORT_UNKNOWN,
discarding the knowledge of whether the target actually supports the
feature. If one toggles back to 'auto', it's no big issue for real
packets, as they'll just end up re-probed the next time they might be
necessary. But features whose support is only reported through
qSupported don't get their corresponding (manually added/maintained)
fields in remote_state objected updated. As we lost the actual status
of the target support for the feature, GDB would need to probe the
qSupported features again, which GDB doesn't do.
But we can avoid that extra traffic, and clean things up, IMO.
Instead of going in that direction, this patch completely decouples
struct packet_config's 'detect' and 'support' fields. E.g., when the
user does "set remote foo-packet off", instead of setting the packet
config's 'support' field to PACKET_DISABLE, the 'support' field is not
touched at all anymore. That is, we end up respecting this simple
table:
| packet_config->detect | packet_config->support | should use packet/feature? |
|-----------------------+------------------------+----------------------------|
| auto | PACKET_ENABLE | PACKET_ENABLE |
| auto | PACKET_DISABLE | PACKET_DISABLE |
| auto | PACKET_UNKNOWN | PACKET_UNKNOWN |
| yes | don't care | PACKET_ENABLE |
| no | don't care | PACKET_DISABLE |
This is implemented by the new packet_support function. With that, we
need to update this pattern throughout:
if (remote_protocol_packets[PACKET_foo].support == PACKET_DISABLE)
to do this instead:
if (packet_support (PACKET_qAttached) == PACKET_DISABLE)
where as mentioned, the packet_support function takes struct
packet_config's 'detect' field into account, like in the table above.
As when the packet is force-disabled or force-enabled, the 'support'
field is just ignored, if the command is set back to auto, we'll
resume respecting whatever the target said it supports. IOW, the end
result is that the 'support' field always represents whether the
target actually supports the packet or not.
After all that, the manually maintained breakpoint_commands and
equivalent fields of struct remote_state can then be eliminated, with
references replaced by checking the result of calling the
packet_support function on the corresponding packet or feature. This
required adding new PACKET_foo enum values for several features that
didn't have it yet. (The patch does not add corresponding "set remote
foo-packet" style commands though, focusing only on bug fixing and
laying the groundwork).
Tested on x86_64 Fedora 17, native GDBserver. The new tests all fail
without this patch.
gdb/
2014-04-25 Pedro Alves <palves@redhat.com>
* remote.c (struct remote_state): Remove multi_process_aware,
non_stop_aware, cond_tracepoints, cond_breakpoints,
breakpoint_commands, fast_tracepoints, static_tracepoints,
install_in_trace, disconnected_tracing,
enable_disable_tracepoints, string_tracing, and
augmented_libraries_svr4_read fields.
(remote_multi_process_p): Move further below in the file.
(struct packet_config): Add comments.
(update_packet_config): Delete function.
(show_packet_config_cmd): Use packet_config_support.
(add_packet_config_cmd): Use NULL as set callback.
(packet_ok): "set remote foo-packet"-style commands no longer
change config->supported -- adjust.
(PACKET_ConditionalTracepoints, PACKET_ConditionalBreakpoints)
(PACKET_BreakpointCommands, PACKET_FastTracepoints)
(PACKET_StaticTracepoints, PACKET_InstallInTrace): Add comments.
(PACKET_QNonStop, PACKET_multiprocess_feature)
(PACKET_EnableDisableTracepoints_feature, PACKET_tracenz_feature)
(PACKET_DisconnectedTracing_feature)
(PACKET_augmented_libraries_svr4_read_feature): New enum values.
(set_remote_protocol_packet_cmd): Delete function.
(packet_config_support, packet_support): New functions.
(set_remote_protocol_Z_packet_cmd): Don't call
update_packet_config.
(remote_query_attached, remote_pass_signals)
(remote_program_signals, remote_threads_info)
(remote_threads_extra_info, remote_start_remote): Use
packet_support.
(remote_start_remote): Use packet_config_support and
packet_support.
(init_all_packet_configs): Set all packets to unknown support,
instead of calling update_packet_config.
(remote_check_symbols): Use packet_support.
(remote_supported_packet): Unconditionally set the packet config's
support status.
(remote_multi_process_feature, remote_non_stop_feature)
(remote_cond_tracepoint_feature, remote_cond_breakpoint_feature)
(remote_breakpoint_commands_feature)
(remote_fast_tracepoint_feature, remote_static_tracepoint_feature)
(remote_install_in_trace_feature)
(remote_disconnected_tracing_feature)
(remote_enable_disable_tracepoint_feature)
(remote_string_tracing_feature)
(remote_augmented_libraries_svr4_read_feature): Delete functions.
(remote_protocol_features): Adjust to use remote_supported_packet
for "augmented-libraries-svr4-read", "multiprocess", "QNonStop",
"ConditionalTracepoints", "ConditionalBreakpoints",
"BreakpointCommands", "FastTracepoints", "StaticTracepoints",
"InstallInTrace", "DisconnectedTracing", "DisconnectedTracing",
"EnableDisableTracepoints", and "tracenz".
(remote_query_supported): Use packet_support.
(remote_open_1): Adjust.
(extended_remote_attach_1): Use packet_support. Switch on the
result of packet_ok instead of checking whether the packet ended
up disabled.
(remote_vcont_resume): Use packet_support.
(remote_resume, remote_stop_ns, fetch_register_using_p)
(remote_prepare_to_store, store_register_using_P)
(check_binary_download, remote_write_bytes): Use packet_support.
(remote_vkill): Use packet_support. Switch on the result of
packet_ok instead of checking whether the packet ended up
disabled.
(extended_remote_supports_disable_randomization): Use
packet_support.
(extended_remote_run): Switch on the result of packet_ok instead
of checking whether the packet ended up disabled.
(remote_insert_breakpoint, remote_remove_breakpoint)
(remote_insert_watchpoint, remote_remove_watchpoint)
(remote_insert_hw_breakpoint, remote_remove_hw_breakpoint): Use
packet_support.
(remote_search_memory): Use packet_config_support.
(remote_get_thread_local_address, remote_get_tib_address)
(remote_hostio_send_command, remote_can_execute_reverse): Use
packet_support.
(remote_supports_cond_tracepoints)
(remote_supports_cond_breakpoints)
(remote_supports_fast_tracepoints)
(remote_supports_static_tracepoints)
(remote_supports_install_in_trace)
(remote_supports_enable_disable_tracepoint)
(remote_supports_string_tracing)
(remote_can_run_breakpoint_commands): Rewrite, checking whether
the packet config says the feature is enabled or disabled.
(remote_download_tracepoint, remote_trace_set_readonly_regions)
(remote_get_trace_status): Use packet_support.
(remote_set_disconnected_tracing): Adjust to check whether the
feature is enabled with packet_support.
(remote_set_trace_buffer_size, remote_use_agent)
(remote_can_use_agent, remote_supports_btrace): Use
packet_support.
(remote_enable_btrace, remote_disable_btrace, remote_read_btrace):
Use packet_config_support.
(remote_augmented_libraries_svr4_read): Rewrite, checking whether
the packet config says the feature is enabled or disabled.
(set_range_stepping): Use packet_support.
gdb/testsuite/
2014-04-25 Pedro Alves <palves@redhat.com>
* gdb.base/cond-eval-mode.exp (warning): Move trailing \r\n to
user.
(top level): Test that "set remote conditional-breakpoints-packet
off" works as intended.
* gdb.base/dprintf.exp: Test that "set remote
breakpoint-commands-packet off" works as intended.
* gdb.trace/change-loc.exp (tracepoint_install_in_trace_disabled):
New function.
(top level): Call it.
* gdb.trace/ftrace.exp (test_fast_tracepoints): Test that "set
remote fast-tracepoints-packet off" works as intended.
* gdb.trace/qtro.exp (gdb_is_target_remote): Moved ...
* lib/gdb.exp (gdb_is_target_remote): ... here.
As we move code on reading unavailable memory to target side, GDB core
side doesn't need the "switching momentarily out of tfind mode" dance.
The target remote knows how to read live memory (through remote_ops).
Remove set_traceframe_number and
make_cleanup_restore_traceframe_number, since they are no longer used.
gdb:
2014-03-22 Yao Qi <yao@codesourcery.com>
* remote.c (target_read_live_memory): Remove.
(memory_xfer_live_readonly_partial): Rename it to
remote_xfer_live_readonly_partial. Remove argument 'object'.
All callers updated. Call remote_read_bytes_1
instead of target_read_live_memory.
* tracepoint.c (set_traceframe_number): Remove.
(make_cleanup_restore_traceframe_number): Likewise .
* tracepoint.h (set_traceframe_number): Remove declaration.
(make_cleanup_restore_traceframe_number): Likewise.
This patch moves code in remote_read_bytes on reading from the remote
stub to a new function remote_read_bytes_1.
gdb:
2014-03-22 Yao Qi <yao@codesourcery.com>
* remote.c (remote_read_bytes): Move code on reading from the
remote stub to ...
(remote_read_bytes_1): ... here. New function.
As a follow-up to
[PATCH 7/8] Adjust read_value_memory to use to_xfer_partial
https://sourceware.org/ml/gdb-patches/2014-02/msg00384.html
this patch moves traceframe_available_memory down to the target side.
After this patch, the gdb core code is cleaner, and code on handling
unavailable memory is moved to remote/tfile/ctf targets.
In details, this patch moves traceframe_available_memory code from
memory_xfer_partial_1 to remote target only, so remote target still
uses traceframe_info mechanism to check unavailable memory, and use
remote_ops to read them from read-only sections. We don't use
traceframe_info mechanism for tfile and ctf target, because it is
fast to iterate all traceframes from trace file, so the summary
information got from traceframe_info is not necessary.
This patch also moves two functions to remote.c from target.c,
because they are only used in remote.c. I'll clean them up in another
patch.
gdb:
2014-03-22 Yao Qi <yao@codesourcery.com>
* ctf.c (ctf_xfer_partial): Check the return value of
exec_read_partial_read_only, if it is not TARGET_XFER_OK,
return TARGET_XFER_UNAVAILABLE.
* tracefile-tfile.c (tfile_xfer_partial): Likewise.
* target.c (target_read_live_memory): Move it to remote.c.
(memory_xfer_live_readonly_partial): Likewise.
(memory_xfer_partial_1): Move some code to remote_read_bytes.
* remote.c (target_read_live_memory): Moved from target.c.
(memory_xfer_live_readonly_partial): Likewise.
(remote_read_bytes): New, factored out from
memory_xfer_partial_1.
As we migrate to the new to_xfer_partial interface, some of previous
tweaks become unnecessary, we don't have to check traceframe is
selected in each target implementation, so this patch below is
reverted.
[PATCH] Send qXfer:traceframe-info:read when traceframe is selected.
https://sourceware.org/ml/gdb-patches/2013-10/msg00752.html
Third, to_traceframe_info is only called when traceframe is selected,
that means it is only called when target is remote, tfile or ctf, so
this patch can be partially reverted,
https://sourceware.org/ml/gdb-patches/2013-04/msg00000.html
gdb:
2014-02-23 Yao Qi <yao@codesourcery.com>
Revert two patches:
2013-10-25 Yao Qi <yao@codesourcery.com>
* remote.c (remote_traceframe_info): Return early if
traceframe is not selected.
2013-07-19 Yao Qi <yao@codesourcery.com>
* target.c (update_current_target): Change the default action
of 'to_traceframe_info' from tcomplain to return_zero.
* target.h (struct target_ops) <to_traceframe_info>: Add more
comments.
From GDB's perspective, independently of how the target really
implements threads, gdb/remote sees all threads as if kernel/system
threads. A rationale along theses lines led to gdbserver storing
thread ids in ptid.lwp in all ports.
Because remote.c is currently using ptid.tid, we can't make gdbserver
and gdb share bits of remote-specific code that manipulates ptids
(e.g., write_ptid/read_ptid).
This patch thus makes remote.c use ptid.lwp instead of ptid.tid.
I believe that on the GDB side too, it's best that we standardize on
process_stratum targets using the ptid.lwp field to store thread ids
anyway. The idea being leave the ptid.tid field free for any
thread_stratum target that might want to sit on top.
Tested on x86_64 Fedora 17, w/ local gdbserver.
gdb/
2014-02-19 Pedro Alves <palves@redhat.com>
* remote.c (remote_thread_alive, write_ptid, read_ptid)
(read_ptid, remote_newthread_step, remote_threads_extra_info)
(remote_get_ada_task_ptid, append_resumption, remote_stop_ns)
(threadalive_test, remote_pid_to_str): Use the ptid.lwp field to
store remote thread ids rather than ptid.tid.
(_initialize_remote): Adjust.
This switches to_read_description to the "new normal" delegation
scheme. This one was a bit trickier than the other changes due to the
way that target_read_description handled delegation. I examined all
the target implementations of to_read_description and changed the ones
returning NULL to instead delegate.
2014-02-19 Tom Tromey <tromey@redhat.com>
* arm-linux-nat.c (arm_linux_read_description): Delegate when
needed.
* corelow.c (core_read_description): Delegate when needed.
* remote.c (remote_read_description): Delegate when needed.
* target-delegates.c: Rebuild.
* target.c (target_read_description): Rewrite.
* target.h (struct target_ops) <to_read_description>: Update
comment. Use TARGET_DEFAULT_RETURN.
Joel Brobecker
Pedro Alves
Gary Benson
Maciej W. Rozycki
Yao Qi
Tom Tromey
Doug Evans
Adrian Sendroiu
Simon Marchi
David Taylor