Currently, when remote debugging, if you type Ctrl-C just while the
target stopped for an internal event, and GDB is busy doing something
that takes a while (e.g., fetching chunks of a shared library off of
the target, with vFile, to process ELF headers and debug info), the
Ctrl-C is lost.
The patch hooks up the QUIT macro to a new target method that lets the
target react to the double-Ctrl-C before the event loop is reached,
which allows reacting to a double-Ctrl-C even when GDB is busy doing
some long operation and not waiting for a stop reply. That end result
is:
(gdb) c
Continuing.
^C
^C
Interrupted while waiting for the program.
Give up waiting? (y or n) y
Quit
(gdb) info threads
Id Target Id Frame
* 1 Thread 11673 0x00007ffff7deb240 in _dl_debug_state () from target:/lib64/ld-linux-x86-64.so.2
(gdb)
If, however, GDB is waiting for a stop reply (because the target has
been resumed, with e.g., vCont;c), but the target isn't responding, we
now get:
(gdb) c
Continuing.
^C
^C
The target is not responding to interrupt requests.
Stop debugging it? (y or n) y
Disconnected from target.
(gdb) info threads
No threads.
This offers to disconnect, because when we're waiting for a stop
reply, there's nothing else we can send the target other than an
interrupt request. And if that doesn't work, there's nothing else we
can do.
The Ctrl-C is presently lost because until we get to a user-visible
stop, the SIGINT handler that is installed is the one that forwards
the interrupt to the remote side, with the \003 "packet" [1]. But,
gdbserver ignores an interrupt request if the program is stopped.
Still, even if it didn't, the server can only report back a
stop-because-of-SIGINT when the program is next resumed. And it may
take a while to actually re-resume the target.
[1] - In the old sync days, the remote target would react to a
double-Ctrl-C by asking users whether they wanted to give up waiting
and disconnect. The code is still there, but it it isn't reacheable
on most hosts, which support serial connections in async mode
(probably only DJGPP doesn't). Even then, in sync mode, remote.c's
SIGINT handler is only installed while the target is resumed, and is
removed as soon as the target sends back a stop reply. That means
that a Ctrl-C just while GDB is processing an internal event can end
up with an odd "Quit" at the prompt instead of "Program stopped by
SIGINT". In contrast, in async mode, remote.c's SIGINT handler is set
up as long as target_terminal_inferior or
target_terminal_ours_for_output are in effect (IOW, until we get a
user-visible stop and call target_terminal_ours), so the user
shouldn't get back a spurious Quit. However, it's still desirable to
be able to interrupt a long-running GDB operation, if GDB takes a
while to re-resume the target or get back to the event loop.
Tested on x86_64 Fedora 20.
gdb/ChangeLog:
2015-08-24 Pedro Alves <palves@redhat.com>
* defs.h (maybe_quit): Declare.
(QUIT): Now calls maybe_quit.
* event-loop.c (clear_async_signal_handler)
(async_signal_handler_is_marked): New functions.
* event-loop.h (async_signal_handler_is_marked)
(clear_async_signal_handler): New declarations.
* remote.c (remote_check_pending_interrupt): New function.
(interrupt_query): Use make_cleanup_restore_target_terminal. No
longer check whether the target is async. If waiting for a stop
reply, and a Ctrl-C as been sent to the target, offer to
disconnect, and throw TARGET_CLOSE_ERROR instead of a quit.
Otherwise do not disconnect and throw a quit.
(_initialize_remote): Install remote_check_pending_interrupt as
to_check_pending_interrupt.
* target.c (target_check_pending_interrupt): New function.
* target.h (struct target_ops) <to_check_pending_interrupt>: New
field.
(target_check_pending_interrupt): New declaration.
* utils.c (maybe_quit): New function.
* target-delegates.c: Regenerate.
GDB provides no indicator of progress during file operations, and can
appear to have locked up during slow remote transfers. This commit
updates GDB to print a warning each time a file is accessed over RSP.
An additional message detailing how to avoid remote transfers is
printed for the first transfer only.
gdb/ChangeLog:
* target.h (struct target_ops) <to_fileio_open>: New argument
warn_if_slow. Update comment. All implementations updated.
(target_fileio_open_warn_if_slow): New declaration.
* target.c (target_fileio_open): Renamed as...
(target_fileio_open_1): ...this. New argument warn_if_slow.
Pass warn_if_slow to implementation. Update debug printing.
(target_fileio_open): New function.
(target_fileio_open_warn_if_slow): Likewise.
* gdb_bfd.c (gdb_bfd_iovec_fileio_open): Use new function
target_fileio_open_warn_if_slow.
gdb/testsuite/ChangeLog:
* gdb.trace/pending.exp: Cope with remote transfer warnings.
With "maint set target-non-stop on" we get:
@@ -66,13 +66,16 @@ Continuing.
interrupt
(gdb) PASS: gdb.base/interrupt-noterm.exp: interrupt
-Program received signal SIGINT, Interrupt.
-PASS: gdb.base/interrupt-noterm.exp: inferior received SIGINT
-testcase src/gdb/testsuite/gdb.base/interrupt-noterm.exp completed in 0 seconds
+[process 12119] #1 stopped.
+0x0000003615ebc6d0 in __nanosleep_nocancel () at ../sysdeps/unix/syscall-template.S:81
+81 T_PSEUDO (SYSCALL_SYMBOL, SYSCALL_NAME, SYSCALL_NARGS)
+FAIL: gdb.base/interrupt-noterm.exp: inferior received SIGINT (timeout)
+testcase src/gdb/testsuite/gdb.base/interrupt-noterm.exp completed in 10 seconds
That is, we get "[$thread] #1 stopped" instead of SIGINT.
The issue is that we don't currently distinguish send
"interrupt/ctrl-c" to target terminal vs "stop/pause" thread well;
both cases go through "target_stop".
And then, the native Linux backend (linux-nat.c) implements
target_stop with SIGSTOP in non-stop mode, and SIGINT in all-stop
mode. Since "maint set target-non-stop on" forces the backend to be
always running in non-stop mode, even though the user-visible behavior
is "set non-stop" is "off", "interrupt" causes a SIGSTOP instead of
the SIGINT the test expects.
Fix this by introducing a target_interrupt method to use in the
"interrupt/ctrl-c" case, so "set non-stop off" can always work the
same irrespective of "maint set target-non-stop on/off". I'm
explictly considering changing the "set non-stop on" behavior as out
of scope here.
Most of the patch is an across-the-board rename of to_stop hook
implementations to to_interrupt. The only targets where something
more than a rename is being done are linux-nat.c and remote.c, which
are the only targets that support async, and thus are the only ones
the core side calls target_stop on.
gdb/ChangeLog:
2015-08-07 Pedro Alves <palves@redhat.com>
* darwin-nat.c (darwin_stop): Rename to ...
(darwin_interrupt): ... this.
(_initialize_darwin_inferior): Adjust.
* gnu-nat.c (gnu_stop): Delete.
(gnu_target): Don't install gnu_stop.
* inf-ptrace.c (inf_ptrace_stop): Rename to ...
(inf_ptrace_interrupt): ... this.
(inf_ptrace_target): Adjust.
* infcmd.c (interrupt_target_1): Use target_interrupt instead of
target_stop.
* linux-nat (linux_nat_stop): Rename to ...
(linux_nat_interrupt): ... this.
(linux_nat_stop): Reimplement.
(linux_nat_add_target): Install linux_nat_interrupt.
* nto-procfs.c (nto_interrupt_twice): Rename to ...
(nto_handle_sigint_twice): ... this.
(nto_interrupt): Rename to ...
(nto_handle_sigint): ... this. Call target_interrupt instead of
target_stop.
(procfs_wait): Adjust.
(procfs_stop): Rename to ...
(procfs_interrupt): ... this.
(init_procfs_targets): Adjust.
* procfs.c (procfs_stop): Rename to ...
(procfs_interrupt): ... this.
(procfs_target): Adjust.
* remote-m32r-sdi.c (m32r_stop): Rename to ...
(m32r_interrupt): ... this.
(init_m32r_ops): Adjust.
* remote-sim.c (gdbsim_stop_inferior): Rename to ...
(gdbsim_interrupt_inferior): ... this.
(gdbsim_stop): Rename to ...
(gdbsim_interrupt): ... this.
(gdbsim_cntrl_c): Adjust.
(init_gdbsim_ops): Adjust.
* remote.c (sync_remote_interrupt): Adjust comments.
(remote_stop_as): Rename to ...
(remote_interrupt_as): ... this.
(remote_stop): Adjust comment.
(remote_interrupt): New function.
(init_remote_ops): Install remote_interrupt.
* target.c (target_interrupt): New function.
* target.h (struct target_ops) <to_interrupt>: New field.
(target_interrupt): New declaration.
* windows-nat.c (windows_stop): Rename to ...
(windows_interrupt): ... this.
* target-delegates.c: Regenerate.
This finally implements user-visible all-stop mode running with the
target_ops backend always in non-stop mode. This is a stepping stone
towards finer-grained control of threads, being able to do interesting
things like thread groups, associating groups with breakpoints, etc.
From the user's perspective, all-stop mode is really just a special
case of being able to stop and resume specific sets of threads, so it
makes sense to do this step first.
With this, even in all-stop, the target is no longer in charge of
stopping all threads before reporting an event to the core -- the core
takes care of it when it sees fit. For example, when "next"- or
"step"-ing, we can avoid stopping and resuming all threads at each
internal single-step, and instead only stop all threads when we're
about to present the stop to the user.
The implementation is almost straight forward, as the heavy lifting
has been done already in previous patches. Basically, we replace
checks for "set non-stop on/off" (the non_stop global), with calls to
a new target_is_non_stop_p function. In a few places, if "set
non-stop off", we stop all threads explicitly, and in a few other
places we resume all threads explicitly, making use of existing
methods that were added for teaching non-stop to step over breakpoints
without displaced stepping.
This adds a new "maint set target-non-stop on/off/auto" knob that
allows both disabling the feature if we find problems, and
force-enable it for development (useful when teaching a target about
this. The default is "auto", which means the feature is enabled if a
new target method says it should be enabled. The patch implements the
method in linux-nat.c, just for illustration, because it still returns
false. We'll need a few follow up fixes before turning it on by
default. This is a separate target method from indicating regular
non-stop support, because e.g., while e.g., native linux-nat.c is
close to regression free with all-stop-non-stop (with following
patches will fixing the remaining regressions), remote.c+gdbserver
will still need more fixing, even though it supports "set non-stop
on".
Tested on x86_64 Fedora 20, native, with and without "set displaced
off", and with and without "maint set target-non-stop on"; and also
against gdbserver.
gdb/ChangeLog:
2015-08-07 Pedro Alves <palves@redhat.com>
* NEWS: Mention "maint set/show target-non-stop".
* breakpoint.c (update_global_location_list): Check
target_is_non_stop_p instead of non_stop.
* infcmd.c (attach_command_post_wait, attach_command): Likewise.
* infrun.c (show_can_use_displaced_stepping)
(can_use_displaced_stepping_p, start_step_over_inferior):
Likewise.
(internal_resume_ptid): New function.
(resume): Use it.
(proceed): Check target_is_non_stop_p instead of non_stop. If in
all-stop mode but the target is always in non-stop mode, start all
the other threads that are implicitly resumed too.
(for_each_just_stopped_thread, fetch_inferior_event)
(adjust_pc_after_break, stop_all_threads): Check
target_is_non_stop_p instead of non_stop.
(handle_inferior_event): Likewise. Handle detach-fork in all-stop
with the target always in non-stop mode.
(handle_signal_stop) <random signal>: Check target_is_non_stop_p
instead of non_stop.
(switch_back_to_stepped_thread): Check target_is_non_stop_p
instead of non_stop.
(keep_going_stepped_thread): Use internal_resume_ptid.
(stop_waiting): If in all-stop mode, and the target is in non-stop
mode, stop all threads.
(keep_going_pass): Likewise, when starting a new in-line step-over
sequence.
* linux-nat.c (get_pending_status, select_event_lwp)
(linux_nat_filter_event, linux_nat_wait_1, linux_nat_wait): Check
target_is_non_stop_p instead of non_stop.
(linux_nat_always_non_stop_p): New function.
(linux_nat_stop): Check target_is_non_stop_p instead of non_stop.
(linux_nat_add_target): Install linux_nat_always_non_stop_p.
* target-delegates.c: Regenerate.
* target.c (target_is_non_stop_p): New function.
(target_non_stop_enabled, target_non_stop_enabled_1): New globals.
(maint_set_target_non_stop_command)
(maint_show_target_non_stop_command): New functions.
(_initilize_target): Install "maint set/show target-non-stop"
commands.
* target.h (struct target_ops) <to_always_non_stop_p>: New field.
(target_non_stop_enabled): New declaration.
(target_is_non_stop_p): New declaration.
gdb/doc/ChangeLog:
2015-08-07 Pedro Alves <palves@redhat.com>
* gdb.texinfo (Maintenance Commands): Document "maint set/show
target-non-stop".
That is, step past breakpoints by:
- pausing all threads
- removing breakpoint at PC
- single-step
- reinsert breakpoint
- restart threads
similarly to all-stop (with displaced stepping disabled). This allows
non-stop to work on targets/architectures without displaced stepping
support. That is, it makes displaced stepping an optimization instead
of a requirement. For example, in principle, all GNU/Linux ports
support non-stop mode at the target_ops level, but not all
corresponding gdbarch's implement displaced stepping. This should
make non-stop work for all (albeit, not as efficiently). And then
there are scenarios where even if the architecture supports displaced
stepping, we can't use it, because we e.g., don't find a usable
address to use as displaced step scratch pad. It should also fix
stepping past watchpoints on targets that have non-continuable
watchpoints in non-stop mode (e.g., PPC, untested). Running the
instruction out of line in the displaced stepping scratch pad doesn't
help that case, as the copied instruction reads/writes the same
watched memory... We can fix that too by teaching GDB to only remove
the watchpoint from the thread that we want to move past the
watchpoint (currently, removing a watchpoint always removes it from
all threads), but again, that can be considered an optimization; not
all targets would support it.
For those familiar with the gdb and gdbserver Linux target_ops
backends, the implementation should look similar, except it is done on
the core side. When we pause threads, we may find they stop with an
interesting event that should be handled later when the thread is
re-resumed, thus we store such events in the thread object, and mark
the event as pending. We should only consume pending events if the
thread is indeed resumed, thus we add a new "resumed" flag to the
thread object. At a later stage, we might add new target methods to
accelerate some of this, like "pause all threads", with corresponding
RSP packets, but we'd still need a fallback method for remote targets
that don't support such packets, so, again, that can be deferred as
optimization.
My _real_ motivation here is making it possible to reimplement
all-stop mode on top of the target always working on non-stop mode, so
that e.g., we can send RSP packets to a remote target even while the
target is running -- can't do that in the all-stop RSP variant, by
design).
Tested on x86_64 Fedora 20, with and without "set displaced off"
forced. The latter forces the new code paths whenever GDB needs to
step past a breakpoint.
gdb/ChangeLog:
2015-08-07 Pedro Alves <pedro@codesourcery.com>
* breakpoint.c (breakpoints_should_be_inserted_now): If any thread
has a pending status, return true.
* gdbthread.h: Include target/waitstatus.h.
(struct thread_suspend_state) <stop_reason, waitstatus_pending_p,
stop_pc>: New fields.
(struct thread_info) <resumed>: New field.
(set_resumed): Declare.
* infrun.c: Include "event-loop.h".
(infrun_async_inferior_event_token, infrun_is_async): New globals.
(infrun_async): New function.
(clear_step_over_info): Add debug output.
(displaced_step_in_progress_any_inferior): New function.
(displaced_step_fixup): New returns int.
(start_step_over): Handle in-line step-overs too. Assert the
thread is marked resumed.
(resume_cleanups): Clear the thread's resumed flag.
(resume): Set the thread's resumed flag. Return early if the
thread has a pending status. Allow stepping a breakpoint with no
signal.
(proceed): Adjust to check 'resumed' instead of 'executing'.
(clear_proceed_status_thread): If the thread has a pending status,
and that status is a finished step, discard the pending status.
(clear_proceed_status): Don't clear step_over_info here.
(random_pending_event_thread, do_target_wait): New functions.
(prepare_for_detach, wait_for_inferior, fetch_inferior_event): Use
do_target_wait.
(wait_one): New function.
(THREAD_STOPPED_BY): New macro.
(thread_stopped_by_watchpoint, thread_stopped_by_sw_breakpoint)
(thread_stopped_by_hw_breakpoint): New functions.
(switch_to_thread_cleanup, save_waitstatus, stop_all_threads): New
functions.
(handle_inferior_event): Also call set_resumed(false) on all
threads implicitly stopped by the event.
(restart_threads, resumed_thread_with_pending_status): New
functions.
(finish_step_over): If we were doing an in-line step-over before,
and no longer are after trying to start a new step-over, restart
all threads. If we have multiple threads with pending events,
save the current event and go through the event loop again.
(handle_signal_stop): Return early if finish_step_over returns
false.
<random signal>: If we get a signal while stepping over a
breakpoint in-line in non-stop mode, restart all threads. Clear
step_over_info before delivering the signal.
(keep_going_stepped_thread): Use internal_error instead of
gdb_assert. Mark the thread as resumed.
(keep_going_pass_signal): Assert the thread isn't already resumed.
If some other thread is doing an in-line step-over, defer the
resume. If we just started a new in-line step-over, stop all
threads. Don't clear step_over_info.
(infrun_async_inferior_event_handler): New function.
(_initialize_infrun): Create async event handler with
infrun_async_inferior_event_handler as callback.
(infrun_async): New declaration.
* target.c (target_async): New function.
* target.h (target_async): Declare macro and readd as function
declaration.
* target/waitstatus.h (enum target_stop_reason)
<TARGET_STOPPED_BY_SINGLE_STEP>: New value.
* thread.c (new_thread): Clear the new waitstatus field.
(set_resumed): New function.
Clarify that currently_stepping works at a higher level than
target_resume.
gdb/ChangeLog:
2015-08-07 Pedro Alves <palves@redhat.com>
* infrun.c (currently_stepping): Extend intro comment.
* target.h (target_resume): Extend intro comment.
We see the following regressions in testing on x86_64-linux,
reverse-step^M
Cannot access memory at address 0x2aaaaaed26c0^M
(gdb) FAIL: gdb.reverse/solib-precsave.exp: reverse-step into solib function one
when GDB reverse step into a function, GDB wants to skip prologue so
it requests TARGET_OBJECT_CODE_MEMORY to read some code memory in
memory_xfer_partial_1. However in dcache_read_memory_partial, the object
becomes TARGET_OBJECT_MEMORY
return ops->to_xfer_partial (ops, TARGET_OBJECT_MEMORY, NULL,
myaddr, NULL, memaddr, len,
xfered_len);
in reverse debugging, ops->to_xfer_partial is record_full_core_xfer_partial
and it will return TARGET_XFER_E_IO because it can't find any records.
The test fails.
At this moment, the delegate relationship is like
dcache -> record-core -> core -> exec
and we want to GDB read memory across targets, which means if the
requested memory isn't found in record-core, GDB can read memory from
core, and exec even further if needed. I find raw_memory_xfer_partial
is exactly what I want.
gdb:
2015-07-29 Yao Qi <yao.qi@linaro.org>
PR record/18691
* dcache.c (dcache_read_memory_partial): Call
raw_memory_xfer_partial.
* target.c (raw_memory_xfer_partial): Make it non-static.
* target.h (raw_memory_xfer_partial): Declare.
This should be just a move with no changes.
gdb/ChangeLog
2015-07-15 Aleksandar Ristovski <aristovski@qnx.com
Jan Kratochvil <jan.kratochvil@redhat.com>
Move linux_find_memory_regions_full & co.
* linux-tdep.c (nat/linux-maps.h): Include.
(gdb_regex.h): Remove the include.
(enum filterflags, struct smaps_vmflags, read_mapping, decode_vmflags)
(mapping_is_anonymous_p, dump_mapping_p): Moved to nat/linux-maps.c.
(linux_find_memory_region_ftype): Moved typedef to nat/linux-maps.h.
(linux_find_memory_regions_full): Moved definition to nat/linux-maps.c.
* nat/linux-maps.c: Include ctype.h, target/target-utils.h, gdb_regex.h
and target/target.h.
(struct smaps_vmflags, read_mapping, decode_vmflags)
(mapping_is_anonymous_p, dump_mapping_p): Move from linux-tdep.c.
(linux_find_memory_regions_full): Move from linux-tdep.c.
* nat/linux-maps.h (read_mapping): New declaration.
(linux_find_memory_region_ftype, enum filterflags): Moved from
linux-tdep.c.
(linux_find_memory_regions_full): New declaration.
* target.c (target/target-utils.h): Include.
(read_alloc_pread_ftype): Moved typedef to target/target-utils.h.
(read_alloc, read_stralloc_func_ftype, read_stralloc): Moved
definitions to target/target-utils.c.
* target.h (target_fileio_read_stralloc): Move it to target/target.h.
* target/target-utils.c (read_alloc, read_stralloc): Move definitions
from target.c.
* target/target-utils.h (read_alloc_pread_ftype): New typedef.
(read_alloc): New declaration.
(read_stralloc_func_ftype): New typedef.
(read_stralloc): New declaration.
* target/target.h (target_fileio_read_stralloc): Move it from target.h.
gdb/gdbserver/ChangeLog
2015-07-15 Aleksandar Ristovski <aristovski@qnx.com
Jan Kratochvil <jan.kratochvil@redhat.com>
* target.c: Include target/target-utils.h and fcntl.h.
(target_fileio_read_stralloc_1_pread, target_fileio_read_stralloc_1)
(target_fileio_read_stralloc): New functions.
If we are reading/writing from a memory object, the length represents
the number of "addresses" to read/write, so the addressable unit size
needs to be taken into account when allocating memory on gdb's side.
gdb/ChangeLog:
* target.c (target_read): Consider addressable unit size when
reading from a memory object.
(read_memory_robust): Same.
(read_whatever_is_readable): Same.
(target_write_with_progress): Consider addressable unit size
when writing to a memory object.
* target.h (target_read): Update documentation.
(target_write): Add documentation.
This contains various cleanups in the target memory read and write code.
They are not directly related to the non-8-bits changes, but they
clarify things a bit down the line.
gdb/ChangeLog:
* target.c (target_read): Rename variables and use
TARGET_XFER_E_IO.
(target_read_with_progress): Same.
(read_memory_robust): Constify parameters and rename
variables.
(read_whatever_is_readable): Constify parameters,
rename variables, adjust formatting.
* target.h (read_memory_robust): Constify parameters.
This commit adds a new argument to all target_fileio functions with
filename arguments to allow the desired inferior to be specified.
This allows GDB to support systems where processes do not necessarily
share a common filesystem.
gdb/ChangeLog:
* target.h (struct inferior): New forward declaration.
(struct target_ops) <to_filesystem_is_local>: Update comment.
(struct target_ops) <to_fileio_open>: New argument inf.
Update comment. All implementations updated.
(struct target_ops) <to_fileio_unlink>: Likewise.
(struct target_ops) <to_fileio_readlink>: Likewise.
(target_filesystem_is_local): Update comment.
(target_fileio_open): New argument inf. Update comment.
(target_fileio_unlink): Likewise.
(target_fileio_readlink): Likewise.
(target_fileio_read_alloc): Likewise.
(target_fileio_read_stralloc): Likewise.
* target.c (target_fileio_open): New argument inf.
Pass inf to implementation. Update debug printing.
(target_fileio_unlink): Likewise.
(target_fileio_readlink): Likewise.
(target_fileio_read_alloc_1): New argument inf. Pass inf
to target_fileio_open.
(target_fileio_read_alloc): New argument inf. Pass inf to
target_fileio_read_alloc_1.
(target_fileio_read_stralloc): Likewise.
* gdb_bfd.c (inferior.h): New include.
(gdb_bfd_iovec_fileio_open): Replace unused "open_closure"
argument with new argument "inferior". Pass inferior to
target_fileio_open.
(gdb_bfd_open): Supply inferior argument to
gdb_bfd_iovec_fileio_open.
* linux-tdep.c (linux_info_proc): Supply inf argument to
relevant target_fileio calls.
(linux_find_memory_regions_full): Likewise.
(linux_fill_prpsinfo): Likewise.
* remote.c (remote_filesystem_is_local): Supply inf
argument to remote_hostio_open.
(remote_file_put): Likewise.
(remote_file_get): Likewise.
(remote_file_delete): Supply inf argument to
remote_hostio_unlink.
The return value of target_can_use_hardware_watchpoint isn't well
documented, so this patch is to update the comments to reflect the
fact. This patch also removes a trailing ";" which is picked up
from Pedro's patch https://sourceware.org/ml/gdb-patches/2015-04/msg00527.html
gdb:
2015-04-17 Yao Qi <yao.qi@linaro.org>
Pedro Alves <palves@redhat.com>
* target.h (target_can_use_hardware_watchpoint): Update comments.
Remove trailing ";".
This commit adds a new packet "qXfer:exec-file:read" to the remote
protocol that can be used to obtain the pathname of the file that
was executed to create a process on the remote system. Support for
this packet is added to GDB and remote_ops.to_pid_to_exec_file is
implemented using it.
gdb/ChangeLog:
* target.h (TARGET_OBJECT_EXEC_FILE): New enum value.
* remote.c (PACKET_qXfer_exec_file): Likewise.
(remote_protocol_features): Register the
"qXfer:exec-file:read" feature.
(remote_xfer_partial): Handle TARGET_OBJECT_EXEC_FILE.
(remote_pid_to_exec_file): New function.
(init_remote_ops): Initialize to_pid_to_exec_file.
(_initialize_remote): Register new "set/show remote
pid-to-exec-file-packet" command.
* NEWS: Announce new qXfer:exec-file:read packet.
gdb/doc/ChangeLog:
* gdb.texinfo (Remote Configuration): Document the "set/show
remote pid-to-exec-file-packet" command.
(General Query Packets): Document the qXfer:exec-file:read
qSupported features. Document the qXfer:exec-file:read packet.
This commit introduces a new target method target_filesystem_is_local
which can be used to determine whether or not the filesystem accessed
by the target_fileio_* methods is the local filesystem.
gdb/ChangeLog:
* target.h (struct target_ops) <to_filesystem_is_local>:
New field.
(target_filesystem_is_local): New macro.
* target-delegates.c: Regenerate.
* remote.c (remote_filesystem_is_local): New function.
(init_remote_ops): Initialize to_filesystem_is_local.
This commit introduces a new target method target_fileio_fstat
which can be used to retrieve information about files opened with
target_fileio_open.
gdb/ChangeLog:
* target.h (struct target_ops) <to_fileio_fstat>: New field.
(target_fileio_fstat): New declaration.
* target.c (target_fileio_fstat): New function.
* inf-child.c (inf_child_fileio_fstat): Likewise.
(inf_child_target): Initialize to_fileio_fstat.
* remote.c (init_remote_ops): Likewise.
All callers of target_async pass it the same callback
(inferior_event_handler). Since both common code and target backends
need to be able to put the target in and out of target async mode at
any given time, there's really no way that a different callback could
be passed. This commit simplifies things, and removes the indirection
altogether. Bonus: with this, gdb's target_async method ends up with
the same signature as gdbserver's.
Tested on x86_64 Fedora 20, native and gdbserver.
gdb/ChangeLog:
2015-03-25 Pedro Alves <palves@redhat.com>
* target.h <to_async>: Replace 'callback' and 'context' parameters
with boolean 'enable' parameter.
(target_async): Replace CALLBACK and CONTEXT parameters with
boolean ENABLE parameter.
* inf-loop.c (inferior_event_handler): Adjust.
* linux-nat.c (linux_nat_attach, linux_nat_resume)
(linux_nat_resume): Adjust.
(async_client_callback, async_client_context): Delete.
(handle_target_event): Call inferior_event_handler directly.
(linux_nat_async): Replace 'callback' and 'context' parameters
with boolean 'enable' parameter. Adjust. Remove references to
async_client_callback and async_client_context.
(linux_nat_close): Adjust.
* record-btrace.c (record_btrace_async): Replace 'callback' and
'context' parameters with boolean 'enable' parameter. Adjust.
(record_btrace_resume): Adjust.
* record-full.c (record_full_async): Replace 'callback' and
'context' parameters with boolean 'enable' parameter. Adjust.
(record_full_resume, record_full_core_resume): Adjust.
* remote.c (struct remote_state) <async_client_callback,
async_client_context>: Delete fields.
(remote_start_remote, extended_remote_attach_1, remote_resume)
(extended_remote_create_inferior): Adjust.
(remote_async_serial_handler): Call inferior_event_handler
directly.
(remote_async): Replace 'callback' and 'context' parameters with
boolean 'enable' parameter. Adjust.
* top.c (gdb_readline_wrapper_cleanup, gdb_readline_wrapper):
Adjust.
* target-delegates.c: Regenerate.
The "set serial parity" command allows the user to control which
parity to use when communicating over a serial connection, rather
than having the parity hardcoded to none.
gdb/ChangeLog:
* NEWS: Mention set/show serial parity command.
* monitor.c (monitor_open): Call serial_setparity.
* remote.c (remote_open_1): Likewise.
* ser-base.c (ser_base_serparity): New function.
* ser-base.h (ser_base_setparity): Add declaration.
* ser-go32.c (dos_ops): Set "setparity" field.
* ser-mingw.c (ser_windows_raw): Do not set state.fParity and
state.Parity.
(ser_windows_setparity): New function.
(hardwire_ops): Add ser_windows_setparity.
(tty_ops): Add NULL for setparity field.
(pipe_ops): Add ser_base_setparity.
(tcp_ops): Likewise.
* ser-pipe.c (pipe_ops): Likewise.
* ser-tcp.c (tcp_ops): Likewise.
* ser-unix.c (hardwire_setparity): Add declaration.
(hardwire_raw): Don't reset PARENB flag.
(hardwire_setparity): New function.
(hardwire_ops): Add hardwire_setparity.
* serial.c (serial_setparity): New function.
(serial_parity): New global.
(parity_none, parity_odd, parity_even, parity_enums, parity):
New static globals.
(set_parity): New function.
(_initialize_serial): Add set/show serial parity commands.
* serial.h (GDBPARITY_NONE): Define.
(GDBPARITY_ODD): Define.
(GDBPARITY_EVEN): Define.
(serial_setparity) Add declaration.
(struct serial_ops): Add setparity field.
* target.h (serial_parity): Add declaration.
gdb/doc/ChangeLog:
* gdb.texinfo (Remote configuration): Document "set/show
serial parity" command.
record-btrace was the only target making use of this, and it no longer
uses it.
gdb/ChangeLog:
2015-03-04 Pedro Alves <palves@redhat.com>
* target.h (struct target_ops) <to_decr_pc_after_break>: Delete.
(target_decr_pc_after_break): Delete declaration.
* target.c (default_target_decr_pc_after_break)
(target_decr_pc_after_break): Delete.
* linux-nat.c (check_stopped_by_breakpoint, linux_nat_wait_1): Use
gdbarch_decr_pc_after_break instead of target_decr_pc_after_break.
* linux-thread-db.c (check_event): Likewise.
* infrun.c (adjust_pc_after_break): Likewise.
* darwin-nat.c (cancel_breakpoint): Likewise.
* aix-thread.c (aix_thread_wait): Likewise.
* target-delegates.c: Regenerate.
The moribund locations heuristics are problematic. This patch teaches
GDB about targets that can reliably tell whether a trap was caused by
a software or hardware breakpoint, and thus don't need moribund
locations, thus bypassing all the problems that mechanism has.
The non-stop-fair-events.exp test is frequently failing currently.
E.g., see https://sourceware.org/ml/gdb-testers/2015-q1/msg03148.html.
The root cause is a fundamental problem with moribund locations. For
example, the stepped_breakpoint logic added by af48d08f breaks in this
case (which is what happens with that test):
- Step thread A, no breakpoint is set at PC.
- The kernel doesn't schedule thread A yet.
- Insert breakpoint at A's PC, for some reason (e.g., a step-resume
breakpoint for thread B).
- Kernel finally schedules thread A.
- thread A's stepped_breakpoint flag is not set, even though it now
stepped a breakpoint instruction.
- adjust_pc_after_break gets the PC wrong, because PC == PREV_PC, but
stepped_breakpoint is not set.
We needed the stepped_breakpoint logic to workaround moribund
locations, because otherwise adjust_pc_after_break could apply an
adjustment when it shouldn't just because there _used_ to be a
breakpoint at PC (a moribund breakpoint location). For example, on
x86, that's wrong if the thread really hasn't executed an int3, but
instead executed some other 1-byte long instruction. Getting the PC
adjustment wrong of course leads to the inferior executing the wrong
instruction.
Other problems with moribund locations are:
- if a true SIGTRAP happens to be raised when the program is
executing the PC that used to have a breakpoint, GDB will assume
that is a trap for a breakpoint that has recently been removed, and
thus we miss reporting the random signal to the user.
- to minimize that, we get rid of moribund location after a while.
That while is defined as just a certain number of events being
processed. That number of events sometimes passes by before a
delayed breakpoint is processed, and GDB confuses the trap for a
random signal, thus reporting the random trap. Once the user
resumes the thread, the program crashes because the PC was not
adjusted...
The fix for all this is to bite the bullet and get rid of heuristics
and instead rely on the target knowing accurately what caused the
SIGTRAP. The target/kernel/stub is in the best position to know what
that, because it can e.g. consult priviledged CPU flags GDB has no
access to, or by knowing which exception vector entry was called when
the instruction trapped, etc. Most debug APIs I've seen to date
report breakpoint hits as a distinct event in some fashion. For
example, on the Linux kernel, whether a breakpoint was executed is
exposed to userspace in the si_code field of the SIGTRAP's siginfo.
On Windows, the debug API reports a EXCEPTION_BREAKPOINT exception
code.
We needed to keep around deleted breakpoints in an on-the-side list
(the moribund locations) for two main reasons:
- Know that a SIGTRAP actually is a delayed event for a hit of a
breakpoint that was removed before the event was processed, and
thus should not be reported as a random signal.
- So we still do the decr_pc_after_break adjustment in that case, so
that the thread is resumed at the correct address.
In the new model, if GDB processes an event the target tells is a
breakpoint trap, and GDB doesn't find the corresponding breakpoint in
its breakpoint tables, it means that event is a delayed event for a
breakpoint that has since been removed, and thus the event should be
ignored.
For the decr_pc_after_after issue, it ends up being much simpler that
on targets that can reliably tell whether a breakpoint trapped, for
the breakpoint trap to present the PC already adjusted. Proper
multi-threading support already implies that targets needs to be doing
decr_pc_after_break adjustment themselves, otherwise for example, in
all-stop if two threads hit a breakpoint simultaneously, and the user
does "info threads", he'll see the non-event thread that hit the
breakpoint stopped at the wrong PC.
This way (target adjusts) also ends up eliminating the need for some
awkward re-incrementing of the PC in the record-full and Linux targets
that we do today, and the need for the target_decr_pc_after_break
hook.
If the target always adjusts, then there's a case where GDB needs to
re-increment the PC. Say, on x86, an "int3" instruction that was
explicitly written in the program traps. In this case, GDB should
report a random SIGTRAP signal to the user, with the PC pointing at
the instruction past the int3, just like if GDB was not debugging the
program. The user may well decide to pass the SIGTRAP to the program
because the program being debugged has a SIGTRAP handler that handles
its own breakpoints, and expects the PC to be unadjusted.
Tested on x86-64 Fedora 20.
gdb/ChangeLog:
2015-03-04 Pedro Alves <palves@redhat.com>
* breakpoint.c (need_moribund_for_location_type): New function.
(bpstat_stop_status): Don't skipping checking moribund locations
of breakpoint types which the target tell caused a stop.
(program_breakpoint_here_p): New function, factored out from ...
(bp_loc_is_permanent): ... this.
(update_global_location_list): Don't create a moribund location if
the target supports reporting stops of the type of the removed
breakpoint.
* breakpoint.h (program_breakpoint_here_p): New declaration.
* infrun.c (adjust_pc_after_break): Return early if the target has
already adjusted the PC. Add comments.
(handle_signal_stop): If nothing explains a signal, and the target
tells us the stop was caused by a software breakpoint, check if
there's a breakpoint instruction in the memory. If so, adjust the
PC before presenting the stop to the user. Otherwise, ignore the
trap. If nothing explains a signal, and the target tells us the
stop was caused by a hardware breakpoint, ignore the trap.
* target.h (struct target_ops) <to_stopped_by_sw_breakpoint,
to_supports_stopped_by_sw_breakpoint, to_stopped_by_hw_breakpoint,
to_supports_stopped_by_hw_breakpoint>: New fields.
(target_stopped_by_sw_breakpoint)
(target_supports_stopped_by_sw_breakpoint)
(target_stopped_by_hw_breakpoint)
(target_supports_stopped_by_hw_breakpoint): Define.
* target-delegates.c: Regenerate.
find_default_create_inferior and find_default_attach were removed in b3ccfe11.
gdb/ChangeLog:
* target.h (find_default_create_inferior): Remove declaration.
(find_default_attach): Likewise.
Fixes:
src/gdb/target.h:753:10: error: use of enum ‘exec_direction_kind’ without previous declaration
in C++ mode. We can't forward declare enums.
gdb/ChangeLog:
2015-02-27 Pedro Alves <palves@redhat.com>
* target.h: Include "infrun.h".
The definition was removed a year ago, but the declaration managed to
stay behind.
gdb/ChangeLog
2015-02-20 Pedro Alves <palves@redhat.com>
* target.h (forward_target_decr_pc_after_break): Delete
declaration.
Add a struct to describe the branch trace configuration and use it for
enabling branch tracing.
The user will be able to set configuration fields for each tracing format
to be used for new threads.
The actual configuration that is active for a given thread will be shown
in the "info record" command.
At the moment, the configuration struct only contains a format field
that is set to the only available format.
The format is the only configuration option that can not be set via set
commands. It is given as argument to the "record btrace" command when
starting recording.
2015-02-09 Markus Metzger <markus.t.metzger@intel.com>
* Makefile.in (XMLFILES): Add btrace-conf.dtd.
* x86-linux-nat.c (x86_linux_enable_btrace): Update parameters.
(x86_linux_btrace_conf): New.
(x86_linux_create_target): Initialize to_btrace_conf.
* nat/linux-btrace.c (linux_enable_btrace): Update parameters.
Check format. Split into this and ...
(linux_enable_bts): ... this.
(linux_btrace_conf): New.
(perf_event_skip_record): Renamed into ...
(perf_event_skip_bts_record): ... this. Updated users.
(linux_disable_btrace): Split into this and ...
(linux_disable_bts): ... this.
(linux_read_btrace): Check format.
* nat/linux-btrace.h (linux_enable_btrace): Update parameters.
(linux_btrace_conf): New.
(btrace_target_info)<ptid>: Moved.
(btrace_target_info)<conf>: New.
(btrace_target_info): Split into this and ...
(btrace_tinfo_bts): ... this. Updated users.
* btrace.c (btrace_enable): Update parameters.
(btrace_conf, parse_xml_btrace_conf_bts, parse_xml_btrace_conf)
(btrace_conf_children, btrace_conf_attributes)
(btrace_conf_elements): New.
* btrace.h (btrace_enable): Update parameters.
(btrace_conf, parse_xml_btrace_conf): New.
* common/btrace-common.h (btrace_config): New.
* feature/btrace-conf.dtd: New.
* record-btrace.c (record_btrace_conf): New.
(record_btrace_cmdlist): New.
(record_btrace_enable_warn, record_btrace_open): Pass
&record_btrace_conf.
(record_btrace_info): Print recording format.
(cmd_record_btrace_bts_start): New.
(cmd_record_btrace_start): Call cmd_record_btrace_bts_start.
(_initialize_record_btrace): Add "record btrace bts" subcommand.
Add "record bts" alias command.
* remote.c (remote_state)<btrace_config>: New.
(remote_btrace_reset, PACKET_qXfer_btrace_conf): New.
(remote_protocol_features): Add qXfer:btrace-conf:read.
(remote_open_1): Call remote_btrace_reset.
(remote_xfer_partial): Handle TARGET_OBJECT_BTRACE_CONF.
(btrace_target_info)<conf>: New.
(btrace_sync_conf, btrace_read_config): New.
(remote_enable_btrace): Update parameters. Call btrace_sync_conf and
btrace_read_conf.
(remote_btrace_conf): New.
(init_remote_ops): Initialize to_btrace_conf.
(_initialize_remote): Add qXfer:btrace-conf packet.
* target.c (target_enable_btrace): Update parameters.
(target_btrace_conf): New.
* target.h (target_enable_btrace): Update parameters.
(target_btrace_conf): New.
(target_object)<TARGET_OBJECT_BTRACE_CONF>: New.
(target_ops)<to_enable_btrace>: Update parameters and comment.
(target_ops)<to_btrace_conf>: New.
* target-delegates: Regenerate.
* target-debug.h (target_debug_print_const_struct_btrace_config_p)
(target_debug_print_const_struct_btrace_target_info_p): New.
NEWS: Announce new command and new packet.
doc/
* gdb.texinfo (Process Record and Replay): Describe the "record
btrace bts" command.
(General Query Packets): Describe qXfer:btrace-conf:read packet.
(Branch Trace Configuration Format): New.
gdbserver/
* linux-low.c (linux_low_enable_btrace): Update parameters.
(linux_low_btrace_conf): New.
(linux_target_ops)<to_btrace_conf>: Initialize.
* server.c (current_btrace_conf): New.
(handle_btrace_enable): Rename to ...
(handle_btrace_enable_bts): ... this. Pass ¤t_btrace_conf
to target_enable_btrace. Update comment. Update users.
(handle_qxfer_btrace_conf): New.
(qxfer_packets): Add btrace-conf entry.
(handle_query): Report qXfer:btrace-conf:read as supported packet.
* target.h (target_ops)<enable_btrace>: Update parameters and comment.
(target_ops)<read_btrace_conf>: New.
(target_enable_btrace): Update parameters.
(target_read_btrace_conf): New.
testsuite/
* gdb.btrace/delta.exp: Update "info record" output.
* gdb.btrace/enable.exp: Update "info record" output.
* gdb.btrace/finish.exp: Update "info record" output.
* gdb.btrace/instruction_history.exp: Update "info record" output.
* gdb.btrace/next.exp: Update "info record" output.
* gdb.btrace/nexti.exp: Update "info record" output.
* gdb.btrace/step.exp: Update "info record" output.
* gdb.btrace/stepi.exp: Update "info record" output.
* gdb.btrace/nohist.exp: Update "info record" output.
Add a format argument to the various supports_btrace functions to check
for support of a specific btrace format. This is to prepare for a new
format.
Removed two redundant calls. The check will be made in the subsequent
btrace_enable call.
2015-02-09 Markus Metzger <markus.t.metzger@intel.com>
* btrace.c (btrace_enable): Pass BTRACE_FORMAT_BTS.
* record-btrace.c (record_btrace_open): Remove call to
target_supports_btrace.
* remote.c (remote_supports_btrace): Update parameters.
* target.c (target_supports_btrace): Update parameters.
* target.h (to_supports_btrace, target_supports_btrace): Update
parameters.
* target-delegates.c: Regenerate.
* target-debug.h (target_debug_print_enum_btrace_format): New.
* nat/linux-btrace.c
(kernel_supports_btrace): Rename into ...
(kernel_supports_bts): ... this. Update users. Update warning text.
(intel_supports_btrace): Rename into ...
(intel_supports_bts): ... this. Update users.
(cpu_supports_btrace): Rename into ...
(cpu_supports_bts): ... this. Update users.
(linux_supports_btrace): Update parameters. Split into this and ...
(linux_supports_bts): ... this.
* nat/linux-btrace.h (linux_supports_btrace): Update parameters.
gdbserver/
* server.c (handle_btrace_general_set): Remove call to
target_supports_btrace.
(supported_btrace_packets): New.
(handle_query): Call supported_btrace_packets.
* target.h: include btrace-common.h.
(btrace_target_info): Removed.
(supports_btrace, target_supports_btrace): Update parameters.
Add a structure to hold the branch trace data and an enum to describe
the format of that data. So far, only BTS is supported. Also added
a NONE format to indicate that no branch trace data is available.
This will make it easier to support different branch trace formats in
the future.
2015-02-09 Markus Metzger <markus.t.metzger@intel.com>
* Makefile.in (SFILES): Add common/btrace-common.c.
(COMMON_OBS): Add common/btrace-common.o.
(btrace-common.o): Add build rules.
* btrace.c (parse_xml_btrace): Update parameters.
(parse_xml_btrace_block): Set format field.
(btrace_add_pc, btrace_fetch): Use struct btrace_data.
(do_btrace_data_cleanup, make_cleanup_btrace_data): New.
(btrace_compute_ftrace): Split into this and...
(btrace_compute_ftrace_bts): ...this.
(btrace_stitch_trace): Split into this and...
(btrace_stitch_bts): ...this.
* btrace.h (parse_xml_btrace): Update parameters.
(make_cleanup_btrace_data): New.
* common/btrace-common.c: New.
* common/btrace-common.h: Include common-defs.h.
(btrace_block_s): Update comment.
(btrace_format): New.
(btrace_format_string): New.
(btrace_data_bts): New.
(btrace_data): New.
(btrace_data_init, btrace_data_fini, btrace_data_empty): New.
* remote.c (remote_read_btrace): Update parameters.
* target.c (target_read_btrace): Update parameters.
* target.h (target_read_btrace): Update parameters.
(target_ops)<to_read_btrace>: Update parameters.
* x86-linux-nat.c (x86_linux_read_btrace): Update parameters.
* target-delegates.c: Regenerate.
* target-debug (target_debug_print_struct_btrace_data_p): New.
* nat/linux-btrace.c (linux_read_btrace): Split into this and...
(linux_read_bts): ...this.
* nat/linux-btrace.h (linux_read_btrace): Update parameters.
gdbserver/
* Makefile.in (SFILES): Add common/btrace-common.c.
(OBS): Add common/btrace-common.o.
(btrace-common.o): Add build rules.
* linux-low: Include btrace-common.h.
(linux_low_read_btrace): Use struct btrace_data. Call
btrace_data_init and btrace_data_fini.
When a thread exits, the terminal is left in mode "terminal_is_ours"
while the target executes. This patch fixes that.
We need to manually restore the terminal setting in this particular
observer. In the case of the other MI observers that call
target_terminal_ours, gdb will end up resuming the inferior later in the
execution and call target_terminal_inferior. In the case of the thread
exit event, we still need to call target_terminal_ours to be able to
print something, but there is nothing that gdb will need to resume after
that. We therefore need to call target_terminal_inferior ourselves.
gdb/ChangeLog:
PR gdb/17627
* target.c (cleanup_restore_target_terminal): New function.
(make_cleanup_restore_target_terminal): New function.
* target.h (make_cleanup_restore_target_terminal): New
declaration.
* mi/mi-interp.c (mi_thread_exit): Use the new cleanup.
Signed-off-by: Simon Marchi <simon.marchi@ericsson.com>
Jan caught an intermittent GDB crash with the annota1.exp test:
Starting program: .../gdb/testsuite/gdb.base/annota1 ^M
[...]
FAIL: gdb.base/annota1.exp: run until main breakpoint (timeout)
[...]
readline: readline_callback_read_char() called with no handler!^M
ERROR: Process no longer exists
All we need to is to continue the inferior in the foreground, and type
a command while the inferior is running. E.g.:
(gdb) set annotate 2
▒▒pre-prompt
(gdb)
▒▒prompt
c
▒▒post-prompt
Continuing.
▒▒starting
▒▒frames-invalid
*inferior is running now*
p 1<ret>
readline: readline_callback_read_char() called with no handler!
Aborted (core dumped)
$
When we run a foreground execution command we call
target_terminal_inferior to stop GDB from processing input, and to put
the inferior's terminal settings in effect. Then we tell readline to
hide the prompt with display_gdb_prompt, which clears readline's input
callback too. When the target stops, we call target_terminal_ours,
which re-installs stdin in the event loop, and then we redisplay the
prompt, reinstalling the readline callbacks.
However, when annotations are in effect, the "frames-invalid"
annotation code calls target_terminal_ours after 'resume' had already
called target_terminal_inferior:
(top-gdb) bt
#0 0x000000000056b82f in annotate_frames_invalid () at gdb/annotate.c:219
#1 0x000000000072e6cc in reinit_frame_cache () at gdb/frame.c:1705
#2 0x0000000000594bb9 in registers_changed_ptid (ptid=...) at gdb/regcache.c:612
#3 0x000000000064cca1 in target_resume (ptid=..., step=1, signal=GDB_SIGNAL_0) at gdb/target.c:2136
#4 0x00000000005f57af in resume (step=1, sig=GDB_SIGNAL_0) at gdb/infrun.c:2263
#5 0x00000000005f6051 in proceed (addr=18446744073709551615, siggnal=GDB_SIGNAL_DEFAULT, step=1) at gdb/infrun.c:2613
And then once we hide the prompt and remove readline's input handler
callback, we're in a bad state. We end up with the target running
supposedly in the foreground, but with stdin still installed on the
event loop. Any input then calls into readline, which aborts because
no rl_linefunc callback handler is installed:
Program received signal SIGABRT, Aborted.
0x0000003b36a35877 in __GI_raise (sig=sig@entry=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:56
56 return INLINE_SYSCALL (tgkill, 3, pid, selftid, sig);
(top-gdb) bt
#0 0x0000003b36a35877 in __GI_raise (sig=sig@entry=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:56
#1 0x0000003b36a36f68 in __GI_abort () at abort.c:89
During symbol reading, debug info gives source 9 included from file at zero line 0.
During symbol reading, debug info gives command-line macro definition with non-zero line 19: _STDC_PREDEF_H 1.
#2 0x0000000000784a25 in rl_callback_read_char () at src/readline/callback.c:116
#3 0x0000000000619111 in rl_callback_read_char_wrapper (client_data=0x0) at src/gdb/event-top.c:167
#4 0x00000000006194e7 in stdin_event_handler (error=0, client_data=0x0) at src/gdb/event-top.c:373
#5 0x00000000006180da in handle_file_event (data=...) at src/gdb/event-loop.c:763
#6 0x00000000006175c1 in process_event () at src/gdb/event-loop.c:340
#7 0x0000000000617688 in gdb_do_one_event () at src/gdb/event-loop.c:404
#8 0x00000000006176d8 in start_event_loop () at src/gdb/event-loop.c:429
#9 0x0000000000619143 in cli_command_loop (data=0x0) at src/gdb/event-top.c:182
#10 0x000000000060f4c8 in current_interp_command_loop () at src/gdb/interps.c:318
#11 0x0000000000610691 in captured_command_loop (data=0x0) at src/gdb/main.c:323
#12 0x000000000060c385 in catch_errors (func=0x610676 <captured_command_loop>, func_args=0x0, errstring=0x900241 "", mask=RETURN_MASK_ALL)
at src/gdb/exceptions.c:237
#13 0x0000000000611b8f in captured_main (data=0x7fffffffd7b0) at src/gdb/main.c:1151
#14 0x000000000060c385 in catch_errors (func=0x610a8e <captured_main>, func_args=0x7fffffffd7b0, errstring=0x900241 "", mask=RETURN_MASK_ALL)
at src/gdb/exceptions.c:237
#15 0x0000000000611bb8 in gdb_main (args=0x7fffffffd7b0) at src/gdb/main.c:1159
#16 0x000000000045ef57 in main (argc=3, argv=0x7fffffffd8b8) at src/gdb/gdb.c:32
The fix is to make the annotation code call target_terminal_inferior
again after printing, if the inferior's settings were in effect.
While at it, when we're doing output only, instead of
target_terminal_ours, we should call target_terminal_ours_for_output.
The latter doesn't actually remove stdin from the event loop, and also
leaves SIGINT forwarded to the target.
New test included.
Tested on x86_64 Fedora 20, native and gdbserver.
gdb/
2014-10-17 Pedro Alves <palves@redhat.com>
PR gdb/17472
* annotate.c (annotate_breakpoints_invalid): Use
target_terminal_our_for_output instead of target_terminal_ours.
Give back the terminal to the target.
(annotate_frames_invalid): Likewise.
gdb/testsuite/
2014-10-17 Pedro Alves <palves@redhat.com>
PR gdb/17472
* gdb.base/annota-input-while-running.c: New file.
* gdb.base/annota-input-while-running.exp: New file.
I found a place that should be giving back the terminal to the target,
but only if the target was already owning it. So I need to add a
getter for who owns the terminal.
The trouble is that several places/target have their own globals to
track this state:
- inflow.c:terminal_is_ours
- remote.c:remote_async_terminal_ours_p
- linux-nat.c:async_terminal_is_ours
- go32-nat.c:terminal_is_ours
While one might think of adding a new target_ops method to query this,
conceptually, this state isn't really part of a particular target_ops.
Considering multi-target, the core shouldn't have to ask all targets
to know whether it's GDB that owns the terminal. There's only one GDB
(or rather, only one top level interpreter).
So what this comment does is add a new global that is tracked by the
core instead. A subsequent pass may later remove the other globals.
Tested on x86_64 Fedora 20, native and gdbserver.
gdb/
2014-10-17 Pedro Alves <palves@redhat.com>
* target.c (enum terminal_state): New enum.
(terminal_state): New global.
(target_terminal_init): New function.
(target_terminal_inferior): Skip if inferior already owns the
terminal.
(target_terminal_ours, target_terminal_ours_for_output): New
functions.
* target.h (target_terminal_init): Convert to function prototype.
(target_terminal_ours_for_output): Convert to function prototype
and tweak comment.
(target_terminal_ours): Convert to function prototype and tweak
comment.
* windows-nat.c (do_initial_windows_stuff): Call
target_terminal_init instead of child_terminal_init_with_pgrp.
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.
This introduces target/target.h. This file declares some functions
that the shared code can use and that clients must implement. It also
changes some shared code to use these functions.
gdb/ChangeLog:
* target/target.h: New file.
* Makefile.in (HFILES_NO_SRCDIR): Add target/target.h.
* target.h: Include target/target.h.
(target_read_memory, target_write_memory): Don't declare.
* target.c (target_read_uint32): New function.
* common/agent.c: Include target/target.h.
[!GDBSERVER]: Don't include target.h.
(helper_thread_id): Type changed to uint32_t.
(agent_get_helper_thread_id): Use target_read_uint32.
(agent_run_command): Always use target_read_memory and
target_write_memory.
(agent_capability): Type changed to uint32_t.
(agent_capability_check): Use target_read_uint32.
gdb/gdbserver/ChangeLog:
* target.h: Include target/target.h.
* target.c (target_read_memory, target_read_uint32)
(target_write_memory): New functions.
The TUI terminal state becomes corrupted (e.g. key sequences such as
Alt_F and Alt_B no longer work) when one attaches to an inferior process
(via "run" or "attach") from within TUI. This terminal corruption
remains until you switch out of TUI mode.
This happens because the terminal state is not properly saved when
switching to and out from TUI mode. Although the functions tui_enable()
and tui_disable() both call the function target_terminal_save_ours() to
save the terminal state, this function is a no-op unless GDB has already
attached to an inferior process. This is because only the "native"
target has a useful implementation of target_terminal_save_ours()
(namely child_terminal_save_ours()) and we only have the "native" target
in our target vector if GDB has already attached to an inferior process.
So without an inferior process, switching to and from TUI mode does not
actually save the terminal state. Therefore when you attach to an
inferior process from within TUI mode, the proper terminal state is not
restored (after swapping from the inferior's terminal back to the GDB
terminal).
To fix this we just have to ensure that the terminal state is always
being properly saved when switching from and to TUI mode. To achieve
this, this patch removes the polymorphic function
target_terminal_save_ours() and replaces it with a regular function
gdb_save_tty_state() that always saves the terminal state.
Tested on x86_64-unknown-linux-gnu by running "make check", no new
regressions.
gdb/ChangeLog:
* target.h (struct target_ops::to_terminal_save_ours): Remove
declaration.
(target_terminal_save_ours): Remove macro.
* target-delegates.c: Regenerate.
* inf-child.c (inf_child_target): Don't set the nonexistent
field to_terminal_save_ours.
* inferior.h (child_terminal_save_ours): Remove declaration.
* terminal.h (gdb_save_tty_state): New declaration.
* inflow.c (child_terminal_save_ours): Rename to ...
(gdb_save_tty_state): ... this.
* tui/tui.c: Include terminal.h.
(tui_enable): Use gdb_save_tty_state instead of
target_terminal_save_ours.
(tui_disable): 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.
I happened to notice that a couple of macros in target.h weren't
properly using parens and as a result had a strange definition.
This patch adds the parens and then fixes the macros to be written as
must have been intended.
Tested by rebuilding.
I'm pushing this as obvious.
2014-07-25 Tom Tromey <tromey@redhat.com>
* target.h (target_stopped_data_address)
(target_watchpoint_addr_within_range): Use "->", not ".". Fix
parentheses.
The target debug methods are inconsistently maintained. Most to_*
methods have some kind of targetdebug awareness, but not all of them
do. The ones that do vary in the quantity and quality of output they
generate.
This patch changes most of the target debug methods to be
automatically generated. All the arguments are printed, and separate
lines are printed for entering and existing the outermost call to the
target stack.
For example now you'd see:
-> multi-thread->to_terminal_ours (...)
-> multi-thread->to_is_async_p (...)
<- multi-thread->to_is_async_p (0x1ebb580) = 1
<- multi-thread->to_terminal_ours (0x1ebb580)
-> multi-thread->to_thread_address_space (...)
<- multi-thread->to_thread_address_space (0x1ebb580, 26802) = 1
In this case you can see nested calls. The "multi-thread" on the left
hand side is the topmost target's shortname.
There are some oddities with this patch. I'm on the fence about it
all, I really just wrote it on a whim.
It's not simple to convert every possible method, since a few don't
participate in target delegation.
Printing is done by type, so I introduced some new
debug-printing-specific typedefs to handle cases where it is nicer to
do something else.
On the plus side, this lays the groundwork for making targetdebug
affect every layer of the target stack. The idea would be to wrap
each target_ops in the stack with its own debug_target, and then you
could see calls propagate down the stack and back up; I suppose with
indentation to make it prettier. (That said there are some gotchas
lurking in this idea due to target stack introspection.)
Regtested on x86-64 Fedora 20.
2014-07-24 Tom Tromey <tromey@redhat.com>
* make-target-delegates (munge_type, write_debugmethod): New
functions.
(debug_names): New global.
($TARGET_DEBUG_PRINTER): New global.
(write_function_header): Strip TARGET_DEBUG_PRINTER from the type
name.
Write debug methods. Generate init_debug_target.
* target-debug.h: New file.
* target-delegates.c: Rebuild.
* target.c: Include target-debug.h.
(debug_target): Hoist definition.
(target_kill, target_get_section_table, target_memory_map)
(target_flash_erase, target_flash_done, target_detach)
(target_disconnect, target_wait, target_resume)
(target_pass_signals, target_program_signals, target_follow_fork)
(target_mourn_inferior, target_search_memory)
(target_thread_address_space, target_close)
(target_find_new_threads, target_core_of_thread)
(target_verify_memory, target_insert_mask_watchpoint)
(target_remove_mask_watchpoint): Remove targetdebug code.
(debug_to_post_attach, debug_to_prepare_to_store)
(debug_to_files_info, debug_to_insert_breakpoint)
(debug_to_remove_breakpoint, debug_to_can_use_hw_breakpoint)
(debug_to_region_ok_for_hw_watchpoint)
(debug_to_can_accel_watchpoint_condition)
(debug_to_stopped_by_watchpoint, debug_to_stopped_data_address)
(debug_to_watchpoint_addr_within_range)
(debug_to_insert_hw_breakpoint, debug_to_remove_hw_breakpoint)
(debug_to_insert_watchpoint, debug_to_remove_watchpoint)
(debug_to_terminal_init, debug_to_terminal_inferior)
(debug_to_terminal_ours_for_output, debug_to_terminal_ours)
(debug_to_terminal_save_ours, debug_to_terminal_info)
(debug_to_load, debug_to_post_startup_inferior)
(debug_to_insert_fork_catchpoint)
(debug_to_remove_fork_catchpoint)
(debug_to_insert_vfork_catchpoint)
(debug_to_remove_vfork_catchpoint)
(debug_to_insert_exec_catchpoint)
(debug_to_remove_exec_catchpoint, debug_to_has_exited)
(debug_to_can_run, debug_to_thread_architecture, debug_to_stop)
(debug_to_rcmd, debug_to_pid_to_exec_file): Remove.
(setup_target_debug): Call init_debug_target.
* target.h (TARGET_DEBUG_PRINTER): New macro.
(struct target_ops) <to_resume, to_wait, to_pass_signals,
to_program_signals>: Use TARGET_DEBUG_PRINTER.
This fixes PR gdb/17130.
The bug is that some code in utils.c was not updated during the target
delegation change:
if (job_control
/* If there is no terminal switching for this target, then we can't
possibly get screwed by the lack of job control. */
|| current_target.to_terminal_ours == NULL)
fatal ("Quit");
else
fatal ("Quit (expect signal SIGINT when the program is resumed)");
After the delegation change, to_terminal_ours will never be NULL.
I think this bug can be seen before the target delegation change by
enabling target debugging -- this would also cause to_terminal_ours to
be non-NULL.
The fix is to introduce a new target_supports_terminal_ours function,
that properly checks the target stack. This is not perhaps ideal, but
I think is a reasonable-enough approach, and in keeping with some
other existing code of the same form.
This patch also fixes a similar bug in target_supports_delete_record.
2014-07-18 Tom Tromey <tromey@redhat.com>
PR gdb/17130:
* utils.c (quit): Use target_supports_terminal_ours.
* target.h (target_supports_terminal_ours): Declare.
* target.c (target_supports_delete_record): Don't check
to_delete_record against NULL.
(target_supports_terminal_ours): New function.
A comment in target.h went past the column limit. This patch
reformats it. I'm pushing this as obvious.
2014-07-16 Tom Tromey <tromey@redhat.com>
* target.h (struct target_ops) <to_delete_record>: Reformat
comment.
This changes to_info_record to use target delegation.
Also, target_info_record was unused, so this patch removes it.
2014-07-07 Tom Tromey <tromey@redhat.com>
* target-delegates.c: Rebuild.
* target.c (target_info_record): Remove.
* record.c (info_record_command): Unconditionally call
to_info_record.
* target.h (struct target_ops) <to_info_record>: Use
TARGET_DEFAULT_IGNORE.
(target_info_record): Remove.
This converts to_get_thread_local_address to use
TARGET_DEFAULT_NORETURN. One possible oddity is that this changes the
text of the kind of exception thrown in some cases. This doesn't seem
to be a problem; in fact perhaps the final call to 'error' in
target_translate_tls_address should be changed to call
generic_tls_error.
2014-07-07 Tom Tromey <tromey@redhat.com>
* target.h (struct target_ops) <to_get_thread_local_address>: Use
TARGET_DEFAULT_NORETURN.
* target.c (generic_tls_error): New function.
(target_translate_tls_address): Don't search target stack.
* target-delegates.c: Rebuild.
* ppc-linux-tdep.c (ppc_linux_spe_context): Don't search target
stack.
* linux-thread-db.c (thread_db_get_thread_local_address):
Unconditionally call beneath target.
This makes arguments to to_get_bookmark and to_goto_bookmark const and
fixes the fallout. Tested by rebuilding. The only thing of note is
the new split between cmd_record_goto and record_goto -- basically
separating the CLI function from a new internal API, to allow const
propagation.
2014-06-26 Tom Tromey <tromey@redhat.com>
* record-full.c (record_full_get_bookmark): Make "args" const.
(record_full_goto_bookmark): Make "raw_bookmark" const.
* record.c (record_goto): New function.
(cmd_record_goto): Use it. Now static.
* record.h (record_goto): Declare.
(cmd_record_goto): Remove declaration.
* target-delegates.c: Rebuild.
* target.h (struct target_ops) <to_get_bookmark,
to_goto_bookmark>: Make parameter const.
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.
Add new target functions to_prepare_to_generate_core and
to_done_generating_core that are called before and after generating a core
file, respectively.
This allows targets to prepare for core file generation and to clean up
afterwards.
gdb/
* target.h (target_ops) <to_prepare_to_generate_core>
<to_done_generating_core>: New.
(target_prepare_to_generate_core, target_done_generating_core): New.
* target.c (target_prepare_to_generate_core)
(target_done_generating_core): New.
* target-delegates.c: Regenerate.
* gcore.c: (write_gcore_file): Rename to ...
(write_gcore_file_1): ...this.
(write_gcore_file): Call target_prepare_to_generate_core
and target_done_generating_core.
This makes a parameter of to_info_proc const and then fixes up some
fallout, including parameters in a couple of gdbarch methods.
I could not test the procfs.c change. I verified it by inspection.
If this causes an error here, it will be trivial to fix.
2014-06-16 Tom Tromey <tromey@redhat.com>
* target.h (struct target_ops) <to_info_proc>: Make parameter
const.
(target_info_proc): Update.
* target.c (target_info_proc): Make "args" const.
* procfs.c (procfs_info_proc): Update.
* linux-tdep.c (linux_info_proc): Update.
(linux_core_info_proc_mappings): Make "args" const.
(linux_core_info_proc): Update.
* gdbarch.sh (info_proc, core_info_proc): Make "args" const.
* gdbarch.c: Rebuild.
* gdbarch.h: Rebuild.
* corelow.c (core_info_proc): Update.
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.
Pedro Alves
Gary Benson
Simon Marchi
Yao Qi
Jan Kratochvil
Yury Grechishchev
Markus Metzger
Joel Brobecker
Patrick Palka
Tom Tromey