Commit a25a5a45 (Fix "breakpoint always-inserted off"; remove
"breakpoint always-inserted auto") regressed non-stop remote
debugging.
This was exposed by mi-nsintrall.exp intermittently failing with a
spurious SIGTRAP.
The problem is that when debugging with "target remote", new threads
the target has spawned but have never reported a stop aren't visible
to GDB until it explicitly resyncs its thread list with the target's.
For example, in a program like this:
int
main (void)
{
pthread_t child_thread;
pthread_create (&child_thread, NULL, child_function, NULL);
return 0; <<<< set breakpoint here
}
If the user sets a breakpoint at the "return" statement, and runs the
program, when that breakpoint hit is reported, GDB is only aware of
the main thread. So if we base the decision to remove or insert
breakpoints from the target based on whether all the threads we know
about are stopped, we'll miss that child_thread is running, and thus
we'll remove breakpoints from the target, even through they should
still remain inserted, otherwise child_thread will miss them.
The break-while-running.exp test actually should also be exposing this
thread-list-out-of-synch problem. That test sets a breakpoint while
the main thread is stopped, but other threads are running. Because
other threads are running, the breakpoint is supposed to be inserted
immediately. But, unless something forces a refetch of the thread
list, like, e.g., "info threads", GDB won't be aware of the other
threads that had been spawned by the main thread, and so won't insert
new or old breakpoints in the target. And it turns out that the test
is exactly doing an explicit "info threads", masking out the
problem... This commit adjust the test to exercise the case of not
issuing "info threads". The test then fails without the GDB fix.
In the ni-nsintrall.exp case, what happens is that several threads hit
the same breakpoint, and when the first thread reports the stop,
because GDB wasn't aware other threads exist, all threads known to GDB
are found stopped, so GDB removes the breakpoints from the target.
The other threads follow up with SIGTRAPs too for that same
breakpoint, which has already been removed. For the first few
threads, the moribund breakpoints machinery suppresses the SIGTRAPs,
but after a few events (precisely '3 * thread_count () + 1' at the
time the breakpoint was removed, see update_global_location_list), the
moribund breakpoint machinery is no longer aware of the removed
breakpoint, and the SIGTRAP is reported as a spurious stop.
The fix is naturally then to stop assuming that if no thread in the
list is executing, then the target is fully stopped. We can't know
that until we fully sync the thread list. Because updating the thread
list on every stop would be too much RSP traffic, I chose instead to
update it whenever we're about to present a stop to the user.
Actually updating the thread list at that point happens to be an item
I had added to the local/remote parity wiki page a while ago:
Native GNU/Linux debugging adds new threads to the thread list as
the program creates them "The [New Thread foo] messages". Remote
debugging can't do that, and it's arguable whether we shouldn't even
stop native debugging from doing that, as it hinders inferior
performance. However, a related issue is that with remote targets
(and gdbserver), even after the program stops, the user still needs
to do "info threads" to pull an updated thread list. This, should
most likely be addressed, so that GDB pulls the list itself, perhaps
just before presenting a stop to the user.
With that in place, the need to delay "Program received signal FOO"
was actually caught by the manythreads.exp test. Without that bit, I
was getting:
[Thread 0x7ffff7f13700 (LWP 4499) exited]
[New Thread 0x7ffff7f0b700 (LWP 4500)]
^C
Program received signal SIGINT, Interrupt.
[New Thread 0x7ffff7f03700 (LWP 4501)] <<< new output
[Switching to Thread 0x7ffff7f0b700 (LWP 4500)]
__GI___nptl_death_event () at events.c:31
31 {
(gdb) FAIL: gdb.threads/manythreads.exp: stop threads 1
That is, I was now getting "New Thread" lines after the "Program
received signal" line, and the test doesn't expect them. As the
number of new threads discovered before and after the "Program
received signal" output is unbounded, it's much nicer to defer
"Program received signal" until after synching the thread list, thus
close to the "switching to thread" output and "current frame/source"
info:
[Thread 0x7ffff7863700 (LWP 7647) exited]
^C[New Thread 0x7ffff786b700 (LWP 7648)]
Program received signal SIGINT, Interrupt.
[Switching to Thread 0x7ffff7fc4740 (LWP 6243)]
__GI___nptl_create_event () at events.c:25
25 {
(gdb) PASS: gdb.threads/manythreads.exp: stop threads 1
Tested on x86_64 Fedora 20, native and gdbserver.
gdb/
2014-10-02 Pedro Alves <palves@redhat.com>
* breakpoint.c (breakpoints_should_be_inserted_now): Use
threads_are_executing.
* breakpoint.h (breakpoints_should_be_inserted_now): Add
describing comment.
* gdbthread.h (threads_are_executing): Declare.
(handle_signal_stop) <random signals>: Don't print about the
signal here if stopping.
(end_stepping_range): Don't notify observers here.
(normal_stop): Update the thread list. If stopped by a random
signal or a stepping range ended, notify observers.
* thread.c (threads_executing): New global.
(init_thread_list): Clear 'threads_executing'.
(set_executing): Set or clear 'threads_executing'.
(threads_are_executing): New function.
(update_threads_executing): New function.
(update_thread_list): Use it.
gdb/testsuite/
2014-10-02 Pedro Alves <palves@redhat.com>
* gdb.threads/break-while-running.exp (test): Add new
'update_thread_list' argument. Skip "info threads" if false.
(top level): Add new 'update_thread_list' axis.
Following an exec with "breakpoint always-inserted on" tries to insert
breakpoints in the new image at the addresses the symbols had in the
old image.
With "always-inserted off", we see:
gdb gdb.multi/multi-arch-exec -ex "set breakpoint always-inserted off"
GNU gdb (GDB) 7.8.50.20140924-cvs
...
(gdb) b main
Breakpoint 1 at 0x400664: file gdb.multi/multi-arch-exec.c, line 24.
^^^^^^^^
(gdb) c
The program is not being run.
(gdb) r
Starting program: testsuite/gdb.multi/multi-arch-exec
Breakpoint 1, main () at gdb/testsuite/gdb.multi/multi-arch-exec.c:24
24 execl (BASEDIR "/multi-arch-exec-hello",
(gdb) c
Continuing.
process 9212 is executing new program: gdb/testsuite/gdb.multi/multi-arch-exec-hello
Breakpoint 1, main () at gdb/testsuite/gdb.multi/hello.c:40
40 bar();
(gdb) info breakpoints
Num Type Disp Enb Address What
1 breakpoint keep y 0x080484e4 in main at gdb/testsuite/gdb.multi/hello.c:40
^^^^^^^^^^
breakpoint already hit 2 times
(gdb)
Note how main was 0x400664 in multi-arch-exec, and 0x080484e4 in
gdb.multi/hello.
With "always-inserted on", we get:
Breakpoint 1, main () at gdb/testsuite/gdb.multi/multi-arch-exec.c:24
24 execl (BASEDIR "/multi-arch-exec-hello",
(gdb) c
Continuing.
infrun: target_wait (-1, status) =
infrun: 9444 [process 9444],
infrun: status->kind = execd
infrun: infwait_normal_state
infrun: TARGET_WAITKIND_EXECD
Warning:
Cannot insert breakpoint 1.
Cannot access memory at address 0x400664
(gdb)
That is, GDB is trying to insert a breakpoint at 0x400664, after the
exec, and then that address happens to not be mapped at all in the new
image.
The problem is that update_breakpoints_after_exec is creating
breakpoints, which ends up in update_global_location_list immediately
inserting breakpoints if "breakpoints always-inserted" is "on".
update_breakpoints_after_exec is called very early when we see an exec
event. At that point, we haven't loaded the symbols of the new
post-exec image yet, and thus haven't reset breakpoint's addresses to
whatever they may be in the new image. All we should be doing in
update_breakpoints_after_exec is deleting breakpoints that no longer
make sense after an exec. So the fix removes those breakpoint
creations.
The question is then, if not here, where are those breakpoints
re-created? Turns out we don't need to do anything else, because at
the end of follow_exec, we call breakpoint_re_set, whose tail is also
creating exactly the same breakpoints update_breakpoints_after_exec is
currently creating:
breakpoint_re_set (void)
{
...
create_overlay_event_breakpoint ();
create_longjmp_master_breakpoint ();
create_std_terminate_master_breakpoint ();
create_exception_master_breakpoint ();
}
A new test is added to exercise this.
Tested on x86_64 Fedora 20.
gdb/
2014-10-02 Pedro Alves <palves@redhat.com>
PR breakpoints/17431
* breakpoint.c (update_breakpoints_after_exec): Don't create
overlay, longjmp, std terminate nor exception breakpoints here.
gdb/testsuite/
2014-10-02 Pedro Alves <palves@redhat.com>
PR breakpoints/17431
* gdb.base/execl-update-breakpoints.c: New file.
* gdb.base/execl-update-breakpoints.exp: New file.
Currently, with "set breakpoint auto-hw off", we'll still try to
insert a software breakpoint at addresses covered by supposedly
read-only or inacessible regions:
(top-gdb) mem 0x443000 0x450000 ro
(top-gdb) set mem inaccessible-by-default off
(top-gdb) disassemble
Dump of assembler code for function main:
0x0000000000443956 <+34>: movq $0x0,0x10(%rax)
=> 0x000000000044395e <+42>: movq $0x0,0x18(%rax)
0x0000000000443966 <+50>: mov -0x24(%rbp),%eax
0x0000000000443969 <+53>: mov %eax,-0x20(%rbp)
End of assembler dump.
(top-gdb) b *0x0000000000443969
Breakpoint 5 at 0x443969: file ../../src/gdb/gdb.c, line 29.
(top-gdb) c
Continuing.
warning: cannot set software breakpoint at readonly address 0x443969
Breakpoint 5, 0x0000000000443969 in main (argc=1, argv=0x7fffffffd918) at ../../src/gdb/gdb.c:29
29 args.argc = argc;
(top-gdb)
We warn, saying that the insertion can't be done, but then proceed
attempting the insertion anyway, and in case of manually added
regions, the insert actually succeeds.
This is a regression; GDB used to fail inserting the breakpoint. More
below.
I stumbled on this as I wrote a test that manually sets up a read-only
memory region with the "mem" command, in order to test GDB's behavior
with breakpoints set on read-only regions, even when the real memory
the breakpoints are set at isn't really read-only. I wanted that in
order to add a test that exercises software single-stepping through
read-only regions.
Note that the memory regions that target_memory_map returns aren't
like e.g., what would expect to see in /proc/PID/maps on Linux.
Instead, they're the physical memory map from the _debuggers_
perspective. E.g., a read-only region would be real ROM or flash
memory, while a read-only+execute mapping in /proc/PID/maps is still
read-write to the debugger (otherwise the debugger wouldn't be able to
set software breakpoints in the code segment).
If one tries to manually write to memory that falls within a memory
region that is known to be read-only, with e.g., "p foo = 1", then we
hit a check in memory_xfer_partial_1 before the write mananges to make
it to the target side.
But writing a software/memory breakpoint nowadays goes through
target_write_raw_memory, and unlike when writing memory with
TARGET_OBJECT_MEMORY, nothing on the TARGET_OBJECT_RAW_MEMORY path
checks whether we're trying to write to a read-only region.
At the time "breakpoint auto-hw" was added, we didn't have the
TARGET_OBJECT_MEMORY vs TARGET_OBJECT_RAW_MEMORY target object
distinction yet, and the code path in memory_xfer_partial that blocks
writes to read-only memory was hit for memory breakpoints too. With
GDB 6.8 we had:
warning: cannot set software breakpoint at readonly address 0000000000443943
Warning:
Cannot insert breakpoint 1.
Error accessing memory address 0x443943: Input/output error.
So I started out by fixing this by adding the memory region validation
to TARGET_OBJECT_RAW_MEMORY too.
But later, when testing against GDBserver, I realized that that would
only block software/memory breakpoints GDB itself inserts with
gdb/mem-break.c. If a target has a to_insert_breakpoint method, the
insertion request will still pass through to the target. So I ended
up converting the "cannot set breakpoint" warning in breakpoint.c to a
real error return, thus blocking the insertion sooner.
With that, we'll end up no longer needing the TARGET_OBJECT_RAW_MEMORY
changes once software single-step breakpoints are converted to real
breakpoints. We need them today as software single-step breakpoints
bypass insert_bp_location. But, it'll be best to leave that in as
safeguard anyway, for other direct uses of TARGET_OBJECT_RAW_MEMORY.
Tested on x86_64 Fedora 20, native and gdbserver.
gdb/
2014-10-01 Pedro Alves <palves@redhat.com>
* breakpoint.c (insert_bp_location): Error out if inserting a
software breakpoint at a read-only address.
* target.c (memory_xfer_check_region): New function, factored out
from ...
(memory_xfer_partial_1): ... this. Make the 'reg_len' local a
ULONGEST.
(target_xfer_partial) <TARGET_OBJECT_RAW_MEMORY>: Check the access
against the memory region attributes.
gdb/testsuite/
2014-10-01 Pedro Alves <palves@redhat.com>
* gdb.base/breakpoint-in-ro-region.c: New file.
* gdb.base/breakpoint-in-ro-region.exp: New file.
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.
This adds a new mode for update_global_location_list, that allows
callers saying "please insert breakpoints, even if
breakpoints_always_inserted_mode() is false". This allows removing a
couple breakpoints_always_inserted_mode checks.
gdb/
2014-09-22 Pedro Alves <palves@redhat.com>
* breakpoint.c (enum ugll_insert_mode): Add UGLL_INSERT.
(insert_breakpoints): Don't call insert_breakpoint_locations here.
Instead, pass UGLL_INSERT to update_global_location_list.
(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.
(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): Handle UGLL_INSERT.
Later we'll want a tristate, but for now, convert to an enum that maps 1-1
with the current boolean's true/false.
gdb/
2014-09-22 Pedro Alves <palves@redhat.com>
* breakpoint.c (enum ugll_insert_mode): New enum.
(update_global_location_list)
(update_global_location_list_nothrow): Change parameter type from
boolean to enum ugll_insert_mode. All callers adjusted.
PR 12526 reports that -location watchpoints against bitfield arguments
trigger false positives when bits around the bitfield, but not the
bitfield itself, are modified.
This happens because -location watchpoints naturally operate at the
byte level, not at the bit level. When the address of a bitfield
lvalue is taken, information about the bitfield (i.e. its offset and
size) is lost in the process.
This information must first be retained throughout the lifetime of the
-location watchpoint. This patch achieves this by adding two new
fields to the watchpoint struct: val_bitpos and val_bitsize. These
fields are set when a watchpoint is first defined in watch_command_1.
They are both equal to zero if the watchpoint is not a -location
watchpoint or if the argument is not a bitfield.
Then these bitfield parameters are used inside update_watchpoint and
watchpoint_check to extract the actual value of the bitfield from the
watchpoint address, with the help of a local helper function
extract_bitfield_from_watchpoint_value.
Finally when creating a HW breakpoint pointing to a bitfield, we
optimize the address and length of the breakpoint. By skipping over
the bytes that don't cover the bitfield, this step reduces the
frequency at which a read watchpoint for the bitfield is triggered.
It also reduces the number of times a false-positive call to
check_watchpoint is triggered for a write watchpoint.
gdb/
PR breakpoints/12526
* breakpoint.h (struct watchpoint): New fields val_bitpos and
val_bitsize.
* breakpoint.c (watch_command_1): Use these fields to retain
bitfield information.
(extract_bitfield_from_watchpoint_value): New function.
(watchpoint_check): Use it.
(update_watchpoint): Use it. Optimize the address and length of a
HW watchpoint pointing to a bitfield.
* value.h (unpack_value_bitfield): New prototype.
* value.c (unpack_value_bitfield): Make extern.
gdb/testsuite/
PR breakpoints/12526
* gdb.base/watch-bitfields.exp: New file.
* gdb.base/watch-bitfields.c: New file.
The IRIX support wants to set a breakpoint to be hit when the startup
phase is complete, which is where shared libraries have been mapped
in. AFAIU, for most IRIX ports, that location is the entry point.
For MIPS IRIX however, GDB needs to set a breakpoint earlier, in
__dbx_link, as explained by:
#ifdef SYS_syssgi
/* On mips-irix, we need to stop the inferior early enough during
the startup phase in order to be able to load the shared library
symbols and insert the breakpoints that are located in these shared
libraries. Stopping at the program entry point is not good enough
because the -init code is executed before the execution reaches
that point.
So what we need to do is to insert a breakpoint in the runtime
loader (rld), more precisely in __dbx_link(). This procedure is
called by rld once all shared libraries have been mapped, but before
the -init code is executed. Unfortuantely, this is not straightforward,
as rld is not part of the executable we are running, and thus we need
the inferior to run until rld itself has been mapped in memory.
For this, we trace all syssgi() syscall exit events. Each time
we detect such an event, we iterate over each text memory maps,
get its associated fd, and scan the symbol table for __dbx_link().
When found, we know that rld has been mapped, and that we can insert
the breakpoint at the symbol address. Once the dbx_link() breakpoint
has been inserted, the syssgi() notifications are no longer necessary,
so they should be canceled. */
proc_trace_syscalls_1 (pi, SYS_syssgi, PR_SYSEXIT, FLAG_SET, 0);
#endif
The loop in irix_solib_create_inferior_hook then runs until whichever
breakpoint is hit first, the one set by solib-irix.c or the one set by
procfs.c.
Note the comment in disable_break talks about __dbx_init, but I think
that's a typo for __dbx_link:
- /* Note that it is possible that we have stopped at a location that
- is different from the location where we inserted our breakpoint.
- On mips-irix, we can actually land in __dbx_init(), so we should
- not check the PC against our breakpoint address here. See procfs.c
- for more details. */
This looks very much like referring to the loop in
irix_solib_create_inferior_hook stopping at __dbx_link instead of at
the entry point.
What this patch does is convert these deprecated raw breakpoints to
standard solib_event breakpoints. When the first solib-event
breakpoint is hit, we delete all solib-event breakpoints. We do that
in the so_ops->handle_event hook.
This allows getting rid of the loop in irix_solib_create_inferior_hook
completely, which should allow properly handling signals and other
events in the early startup phase, like in SVR4.
Built on x86_64 Fedora 20 with --enable-targets=all (builds
solib-irix.c).
Joel tested that with an earlier version of this patch "info shared"
after starting a program gave the same list of shared libraries as
before.
gdb/ChangeLog:
2014-09-12 Pedro Alves <palves@redhat.com>
* breakpoint.c (remove_solib_event_breakpoints_at_next_stop)
(create_and_insert_solib_event_breakpoint): New functions.
* breakpoint.h (create_and_insert_solib_event_breakpoint)
(remove_solib_event_breakpoints_at_next_stop): New declarations.
* procfs.c (dbx_link_bpt_addr, dbx_link_bpt): Delete globals.
(remove_dbx_link_breakpoint): Delete function.
(insert_dbx_link_bpt_in_file): Use
create_and_insert_solib_event_breakpoint instead of
deprecated_insert_raw_breakpoint.
(procfs_wait): Don't check whether we hit __dbx_link here.
(procfs_mourn_inferior): Don't delete the __dbx_link breakpoint
here.
* solib-irix.c (base_breakpoint): Delete global.
(disable_break): Delete function.
(enable_break): Use create_solib_event_breakpoint
instead of deprecated_insert_raw_breakpoint.
(irix_solib_handle_event): New function.
(irix_solib_create_inferior_hook): Don't run the target or disable
the mapping-complete breakpoint here.
(_initialize_irix_solib): Install irix_solib_handle_event as
so_ops->handle_event hook.
This constifies a few functions in cli-utils -- get_number_trailer and
friends -- and then fixes the fallout.
2014-07-30 Tom Tromey <tromey@redhat.com>
* breakpoint.c (map_breakpoint_numbers): Update.
* cli/cli-utils.c (get_number_trailer): Make "pp" const. Update.
(get_number_const): New function.
(get_number): Rewrite using get_number_const.
(init_number_or_range): Make "string" const.
(number_is_in_list): Make "list" const.
* cli/cli-utils.h (get_number_const): Declare.
(struct get_number_or_range_state) <string, end_ptr>: Now const.
(init_number_or_range, number_is_in_list): Update.
* printcmd.c (map_display_numbers): Update.
* value.c (value_from_history_ref): Constify.
* value.h (value_from_history_ref): Update.
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.
BINOP_RANGE was added by the following commit for chill language.
commit badefd2800
Author: Per Bothner <per@bothner.com>
Date: Wed Nov 29 22:59:31 1995 +0000
* expression.h (enum exp_opcode): Add BINOP_RANGE.
* expprint.c (dump_expression): Support BINOP_RANGE.
* eval.c (evaluate_subexp_standard): Handle BINOP_RANGE (as error).
(case MULTI_SUBSCRIPT): Fix broken f77 value->int ad hoc conversion.
* ch-lang.c (chill_op_print_tab): Support BINOP_RANGE.
(evaluate_subexp_chill): Error on BINOP_COMMA.
Chill language is no longer supported, so we can remove BINOP_RANGE too.
This patch is to remove BINOP_RANGE.
gdb:
2014-07-20 Yao Qi <yao@codesourcery.com>
* std-operator.def: Remove BINOP_RANGE.
* breakpoint.c (watchpoint_exp_is_const): Update.
* expprint.c (dump_subexp_body_standard): Likewise.
* eval.c (init_array_element): Remove dead code.
(evaluate_subexp_standard): Likewise.
Chill language support was removed several years ago, and BINOP_IN
isn't used for Pascal. This patch is to remove BINOP_IN.
gdb:
2014-07-20 Yao Qi <yao@codesourcery.com>
* std-operator.def: Remove BINOP_IN.
* breakpoint.c (watchpoint_exp_is_const): Update.
* eval.c (evaluate_subexp_standard): Likewise.
* expprint.c (dump_subexp_body_standard): Likewise.
This patch changes a few more spots to use either cmd_sfunc_ftype or
cmd_cfunc_ftype, as appropriate. This is a bit cleaner.
Tested by rebuilding.
2014-07-01 Tom Tromey <tromey@redhat.com>
* breakpoint.c (add_catch_command): Use cmd_sfunc_ftype.
* breakpoint.h (add_catch_command): Use cmd_sfunc_ftype.
* cli/cli-decode.c (cmd_cfunc_eq, add_cmd, add_prefix_cmd)
(add_abbrev_prefix_cmd, add_info, add_com): Use cmd_cfunc_ftype.
* command.h (cmd_cfunc_ftype): Move earlier.
(add_cmd, add_prefix_cmd, add_abbrev_prefix_cmd, cmd_cfunc_eq)
(add_com, add_info): Use cmd_cfunc_ftype.
This patch is to add ptid into dummy_frame and extend frame_id to
dummy_frame_id (which has a ptid field). With this change, GDB uses
dummy_frame_id (thread ptid and frame_id) to find the dummy frames.
Currently, dummy frames are looked up by frame_id, which isn't
accurate in non-stop or multi-process mode. The test case
gdb.multi/dummy-frame-restore.exp shows the problem and this patch can
fix it.
Test dummy-frame-restore.exp makes two inferiors stop at
different functions, say, inferior 1 stops at f1 while inferior 2
stops at f2. Set a breakpoint to a function, do the inferior call
in two inferiors, and GDB has two dummy frames of the same frame_id.
When the inferior call is finished, GDB will look up a dummy frame
from its stack/list and restore the inferior's regcache. Two
inferiors are finished in different orders, the inferiors' states are
restored differently, which is wrong. Running dummy-frame-restore.exp
under un-patched GDB, we'll get two fails:
FAIL: gdb.multi/dummy-frame-restore.exp: inf 2 first: after infcall: bt in inferior 2
FAIL: gdb.multi/dummy-frame-restore.exp: inf 2 first: after infcall: bt in inferior 1
With this patch applied, GDB will choose the correct dummy_frame to
restore for a given inferior, because ptid is considered when looking up
dummy frames. Two fails above are fixed.
Regression tested on x86_64-linux, both native and gdbserver.
gdb:
2014-06-27 Yao Qi <yao@codesourcery.com>
* breakpoint.c (check_longjmp_breakpoint_for_call_dummy):
Change parameter type to 'struct thread_info *'. Caller
updated.
* breakpoint.h (check_longjmp_breakpoint_for_call_dummy):
Update declaration.
* dummy-frame.c (struct dummy_frame_id): New.
(dummy_frame_id_eq): New function.
(struct dummy_frame) <id>: Change its type to 'struct
dummy_frame_id'.
(dummy_frame_push): Add parameter ptid and save it in
dummy_frame_id.
(pop_dummy_frame_bpt): Use ptid of dummy_frame instead of
inferior_ptid.
(pop_dummy_frame): Assert that the ptid of dummy_frame equals
to inferior_ptid.
(lookup_dummy_frame): Change parameter type to 'struct
dummy_frame_id *'. Callers updated. Call dummy_frame_id_eq
instead of frame_id_eq.
(dummy_frame_pop): Add parameter ptid. Callers updated.
Update comments. Compose dummy_frame_id and pass it to
lookup_dummy_frame.
(dummy_frame_discard): Add parameter ptid.
(dummy_frame_sniffer): Compose dummy_frame_id and call
dummy_frame_id_eq instead of frame_id_eq.
(fprint_dummy_frames): Print ptid.
* dummy-frame.h: Remove comments.
(dummy_frame_push): Add ptid in declaration.
(dummy_frame_pop, dummy_frame_discard): Likewise.
gdb/testsuite:
2014-06-27 Yao Qi <yao@codesourcery.com>
* gdb.multi/dummy-frame-restore.exp: New.
* gdb.multi/dummy-frame-restore.c: New.
gdb/doc:
2014-06-27 Yao Qi <yao@codesourcery.com>
* gdb.texinfo (Maintenance Commands): Update the output of
'maint print dummy-frames' command.
Generally, the blockvector ought to be readonly. So, this patch makes
the blockvector const in the symtab, and also changes various
blockvector APIs to be const.
This patch has a couple of spots that cast away const. I consider
these to be ok because they occur in mdebugread and are used while
constructing the blockvector. I have added comments at these spots.
2014-06-18 Tom Tromey <tromey@redhat.com>
* symtab.h (struct symtab) <blockvector>: Now const.
* ada-lang.c (ada_add_global_exceptions): Update.
* buildsym.c (augment_type_symtab): Update.
* dwarf2read.c (dw2_lookup_symbol): Update.
* jit.c (finalize_symtab): Update.
* jv-lang.c (add_class_symtab_symbol): Update.
* mdebugread.c (parse_symbol, add_block, sort_blocks, new_symtab):
Update.
* objfiles.c (objfile_relocate1): Update.
* psymtab.c (lookup_symbol_aux_psymtabs)
(maintenance_check_psymtabs): Update.
* python/py-symtab.c (stpy_global_block, stpy_static_block):
Update.
* spu-tdep.c (spu_catch_start): Update.
* symmisc.c (dump_symtab_1): Update.
* symtab.c (lookup_global_symbol_from_objfile)
(lookup_symbol_aux_objfile, lookup_symbol_aux_quick)
(basic_lookup_transparent_type_quick)
(basic_lookup_transparent_type, find_pc_sect_symtab)
(find_pc_sect_line, search_symbols): Update.
* block.c (find_block_in_blockvector): Make "bl" const.
(blockvector_for_pc_sect, blockvector_for_pc): Make return type
const.
(blockvector_contains_pc): Make "bv" const.
(block_for_pc_sect): Update.
* block.h (blockvector_for_pc, blockvector_for_pc_sect)
(blockvector_contains_pc): Update.
* breakpoint.c (resolve_sal_pc): Update.
* inline-frame.c (block_starting_point_at): Update.
Using the test program gdb.base/foll-fork.c, with follow-fork-mode set to
"child" and detach-on-fork set to "off", stepping or running past the fork
call results in the child process running to completion, when it should
just finish the single step. In addition, the breakpoint is not removed
from the parent process, so if it is resumed it receives a SIGTRAP.
Cause:
No matter what the setting for detach-on-fork, when stepping past a fork,
the single-step breakpoint (step_resume_breakpoint) is not handled
correctly in the parent. The SR breakpoint is cloned for the child
process, but before the clone is associated with the child it is treated as
a duplicate of the original, associated wth the parent. This results in
the insertion state of the original SR breakpoint and the clone being
"swapped" by breakpoint.c:update_global_location_list, so that the clone is
marked as inserted.
In the case where the parent is not detached, the two breakpoints remain in
that state. The breakpoint is never inserted in the child, because
although the cloned SR breakpoint is associated with the child, it is
marked as inserted. When the child is resumed, it runs to completion. The
breakpoint is never removed from the parent, so that if it is resumed after
the child exits, it gets a SIGTRAP.
Here is the sequence of events:
1) handle_inferior_event: FORK event is recognized.
2) handle_inferior_event: detach_breakpoints removes all breakpoints
from the child.
3) follow_fork: the parent SR breakpoint is cloned. Part of this procedure
is to call update_global_location_list, which swaps the insertion state of
the original and cloned SR breakpoints as part of ensuring that duplicate
breakpoints are only inserted once. At this point the original SR
breakpoint is not marked as inserted, and the clone is. The breakpoint is
actually inserted in the parent but not the child.
4) follow_fork: the original breakpoint is deleted by calling
delete_step_resume_breakpoint. Since the original is not marked as
inserted, the actual breakpoint remains in the parent process.
update_global_location_list is called again as part of the deletion. The
clone is still associated with the parent, but since it is marked as
enabled and inserted, the breakpoint is left in the parent.
5) follow_fork: if detach-on-fork is 'on', the actual breakpoint will be
removed from the parent in target_detach, based on the cloned breakpoint
still associated with the parent. Then the clone is no longer marked as
inserted. In follow_inferior_reset_breakpoints the clone is associated
with the child, and can be inserted.
If detach-on-fork is 'off', the actual breakpoint in the parent is never
removed (although the breakpoint had been deleted from the list). Since
the clone continues to be marked 'inserted', the SR breakpoint is never
inserted in the child.
Fix:
Set the cloned breakpoint as disabled from the moment it is created. This
is done by modifying clone_momentary_breakpoint to take an additional
argument, LOC_ENABLED, which is used as the value of the
bp_location->enabled member. The clone must be disabled at that point
because clone_momentary_breakpoint calls update_global_location_list, which
will swap treat the clone as a duplicate of the original breakpoint if it
is enabled.
All the calls to clone_momentary_breakpoint had to be modified to pass '1'
or '0'. I looked at implementing an enum for the enabled member, but
concluded that readability would suffer because there are so many places it
is used as a boolean, e.g. "if (bl->enabled)".
In follow_inferior_reset_breakpoints the clone is set to enabled once it
has been associated with the child process. With this, the bp_location
'inserted' member is maintained correctly throughout the follow-fork
procedure and the behavior is as expected.
The same treatment is given to the exception_resume_breakpoint when
following a fork.
Testing:
Ran 'make check' on Linux x64.
Along with the fix above, the coverage of the follow-fork test
gdb.base/foll-fork.exp was expanded to:
1) cover all the combinations of values for
follow-fork-mode and detach-on-fork
2) make sure that both user breakpoints and
single-step breakpoints are propagated
correctly to the child
3) check that the inferior list has the
expected contents after following the fork.
4) check that unfollowed, undetached inferiors
can be resumed.
gdb/
2014-06-18 Don Breazeal <donb@codesourcery.com>
* breakpoint.c (set_longjmp_breakpoint): Call
momentary_breakpoint_from_master with additional argument.
(set_longjmp_breakpoint_for_call_dummy): Call
momentary_breakpoint_from_master with additional argument.
(set_std_terminate_breakpoint): Call
momentary_breakpoint_from_master with additional argument.
(momentary_breakpoint_from_master): Add argument to function
definition and use it to initialize structure member flag.
(clone_momentary_breakpoint): Call
momentary_breakpoint_from_master with additional argument.
* infrun.c (follow_inferior_reset_breakpoints): Clear structure
member flags set in momentary_breakpoint_from_master.
gdb/testsuite/
2014-06-18 Don Breazeal <donb@codesourcery.com>
* gdb.base/foll-fork.exp (default_fork_parent_follow):
Deleted procedure.
(explicit_fork_parent_follow): Deleted procedure.
(explicit_fork_child_follow): Deleted procedure.
(test_follow_fork): New procedure.
(do_fork_tests): Replace calls to deleted procedures with
calls to test_follow_fork and reset GDB for subsequent
procedure calls.
Turns out there's a difference between loading the program with "gdb
PROGRAM", vs loading it with "(gdb) file PROGRAM". The latter results
in the objfile ending up with OBJF_USERLOADED set, while not with the
former. (That difference seems bogus, but still that's not the point
of this patch. We can revisit that afterwards.)
The new code that suppresses breakpoint removal errors for
add-symbol-file objects ends up being too greedy:
/* In some cases, we might not be able to remove a breakpoint in
a shared library that has already been removed, but we have
not yet processed the shlib unload event. Similarly for an
unloaded add-symbol-file object - the user might not yet have
had the chance to remove-symbol-file it. shlib_disabled will
be set if the library/object has already been removed, but
the breakpoint hasn't been uninserted yet, e.g., after
"nosharedlibrary" or "remove-symbol-file" with breakpoints
always-inserted mode. */
if (val
&& (bl->loc_type == bp_loc_software_breakpoint
&& (bl->shlib_disabled
|| solib_name_from_address (bl->pspace, bl->address)
|| userloaded_objfile_contains_address_p (bl->pspace,
bl->address))))
val = 0;
as it turns out that OBJF_USERLOADED can be set for objfiles loaded by
some other means not add-symbol-file. In this case, symbol-file (or
"file", which is really just "exec-file"+"symbol-file").
Recall that add-symbol-file is documented as:
(gdb) help add-symbol-file
Load symbols from FILE, assuming FILE has been dynamically loaded.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
And it's the "dynamically loaded" aspect that the breakpoint.c code
cares about. So make add-symbol-file set OBJF_SHARED on its objfiles
too, and tweak the breakpoint.c code to look for OBJF_SHARED instead
of OBJF_USERLOADED.
This restores back the missing breakpoint removal warning when we let
sss-bp-on-user-bp-2.exp run on native GNU/Linux
(https://sourceware.org/ml/gdb-patches/2014-06/msg00335.html):
(gdb) PASS: gdb.base/sss-bp-on-user-bp-2.exp: define stepi_del_break
stepi_del_break
warning: Error removing breakpoint 3
(gdb) FAIL: gdb.base/sss-bp-on-user-bp-2.exp: stepi_del_break
I say "restores" because this was GDB's behavior in 7.7 and earlier.
And, likewise, "file" with no arguments only started turning
breakpoints set in the main executable to "<pending>" with the
remote-symbol-file patch (63644780). The old behavior is now
restored, and we break-unload-file.exp test now exercizes both "gdb;
file PROGRAM" and "gdb PROGRAM".
gdb/
2014-06-16 Pedro Alves <palves@redhat.com>
* breakpoint.c (insert_bp_location, remove_breakpoint_1): Adjust.
(disable_breakpoints_in_freed_objfile): Skip objfiles that don't
have OBJF_SHARED set.
* objfiles.c (userloaded_objfile_contains_address_p): Rename to...
(shared_objfile_contains_address_p): ... this. Check OBJF_SHARED
instead of OBJF_USERLOADED.
* objfiles.h (OBJF_SHARED): Update comment.
(userloaded_objfile_contains_address_p): Rename to ...
(shared_objfile_contains_address_p): ... this, and update
comments.
* symfile.c (add_symbol_file_command): Also set OBJF_SHARED in the
new objfile.
(remove_symbol_file_command): Skip objfiles that don't have
OBJF_SHARED set.
gdb/testsuite/
2014-06-16 Pedro Alves <palves@redhat.com>
* gdb.base/break-main-file-remove-fail.c: New file.
* gdb.base/break-main-file-remove-fail.exp: New file.
* gdb.base/break-unload-file.exp: Use build_executable instead of
prepare_for_testing.
(test_break): New parameter "initial_load". Handle it.
(top level): Add initial_load cmdline/file axis.
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.
with the following code...
12 Nested; -- break #1
13 return I; -- break #2
14 end;
(line 12 is a call to function Nested)
... we have noticed the following errorneous behavior on ppc-aix,
where, after having inserted a breakpoint at line 12 and line 13,
and continuing from the breakpoint at line 12, the program never
stops at line 13, running away until the program terminates:
% gdb -q func
(gdb) b func.adb:12
Breakpoint 1 at 0x10000a24: file func.adb, line 12.
(gdb) b func.adb:13
Breakpoint 2 at 0x10000a28: file func.adb, line 13.
(gdb) run
Starting program: /[...]/func
Breakpoint 1, func () at func.adb:12
12 Nested; -- break #1
(gdb) c
Continuing.
[Inferior 1 (process 4128872) exited with code 02]
When resuming from the first breakpoint, GDB first tries to step out
of that first breakpoint. We rely on software single-stepping on this
platform, and it just so happens that the address of the first
software single-step breakpoint is the same as the user's breakpoint
#2 (0x10000a28). So, with infrun and target traces turned on (but
uninteresting traces snip'ed off), the "continue" operation looks like
this:
(gdb) c
### First, we insert the user breakpoints (the second one is an internal
### breakpoint on __pthread_init). The first user breakpoint is not
### inserted as we need to step out of it first.
target_insert_breakpoint (0x0000000010000a28, xxx) = 0
target_insert_breakpoint (0x00000000d03f3800, xxx) = 0
### Then we proceed with the step-out-of-breakpoint...
infrun: resume (step=1, signal=GDB_SIGNAL_0), trap_expected=1, current thread [process 15335610] at 0x10000a24
### That's when we insert the SSS breakpoints...
target_insert_breakpoint (0x0000000010000a28, xxx) = 0
target_insert_breakpoint (0x00000000100009ac, xxx) = 0
### ... then let the inferior resume...
target_resume (15335610, continue, 0)
infrun: wait_for_inferior ()
target_wait (-1, status, options={}) = 15335610, status->kind = stopped, signal = GDB_SIGNAL_TRAP
infrun: target_wait (-1, status) =
infrun: 15335610 [process 15335610],
infrun: status->kind = stopped, signal = GDB_SIGNAL_TRAP
infrun: infwait_normal_state
infrun: TARGET_WAITKIND_STOPPED
infrun: stop_pc = 0x100009ac
### At this point, we stopped at the second SSS breakpoint...
target_stopped_by_watchpoint () = 0
### We remove the SSS breakpoints...
target_remove_breakpoint (0x0000000010000a28, xxx) = 0
target_remove_breakpoint (0x00000000100009ac, xxx) = 0
target_stopped_by_watchpoint () = 0
### We find that we're not done, so we resume....
infrun: no stepping, continue
### And thus insert the user breakpoints again, except we're not
### inserting the second breakpoint?!?
target_insert_breakpoint (0x0000000010000a24, xxx) = 0
infrun: resume (step=0, signal=GDB_SIGNAL_0), trap_expected=0, current thread [process 15335610] at 0x100009ac
target_resume (-1, continue, 0)
infrun: prepare_to_wait
target_wait (-1, status, options={}) = 15335610, status->kind = exited, status = 2
What happens is that the removal of the software single-step
breakpoints effectively removed the breakpoint instruction from
inferior memory. But because such breakpoints are inserted directly
as raw breakpoints rather than through the normal chain of
breakpoints, we fail to notice that one of the user breakpoints points
to the same address and that this user breakpoint is therefore
effectively un-inserted. When resuming after the single-step, GDB
thinks that the user breakpoint is still inserted and therefore does
not need to insert it again.
This patch teaches the insert and remove routines of both regular and
raw breakpoints to be aware of each other. Special care needs to be
applied in case the target supports evaluation of breakpoint
conditions or commands.
gdb/ChangeLog:
PR breakpoints/17000
* breakpoint.c (find_non_raw_software_breakpoint_inserted_here):
New function, extracted from software_breakpoint_inserted_here_p.
(software_breakpoint_inserted_here_p): Replace factored out code
by call to find_non_raw_software_breakpoint_inserted_here.
(bp_target_info_copy_insertion_state): New function.
(bkpt_insert_location): Handle the case of a single-step
breakpoint already inserted at the same address.
(bkpt_remove_location): Handle the case of a single-step
breakpoint still inserted at the same address.
(deprecated_insert_raw_breakpoint): Handle the case of non-raw
breakpoint already inserted at the same address.
(deprecated_remove_raw_breakpoint): Handle the case of a
non-raw breakpoint still inserted at the same address.
(find_single_step_breakpoint): New function, extracted from
single_step_breakpoint_inserted_here_p.
(find_single_step_breakpoint): New function,
factored out from single_step_breakpoint_inserted_here_p.
(single_step_breakpoint_inserted_here_p): Reimplement.
gdb/testsuite/ChangeLog:
PR breakpoints/17000
* gdb.base/sss-bp-on-user-bp.exp: Remove kfail.
* gdb.base/sss-bp-on-user-bp-2.exp: Remove kfail.
Tested on ppc-aix with AdaCore's testsuite. Tested on x86_64-linux,
(native and gdbserver) with the official testsuite. Also tested on
x86_64-linux through Pedro's branch enabling software single-stepping
on that platform (native and gdbserver).
While the full fix for PR 15180 isn't in, it's best if we at least
make sure that GDB doesn't lose control when a breakpoint is set at
the same address as a dprintf.
gdb/
2014-06-02 Pedro Alves <palves@redhat.com>
* breakpoint.c (build_target_command_list): Don't build a command
list if we have any duplicate location that isn't a dprintf.
gdb/testsuite/
2014-06-02 Pedro Alves <palves@redhat.com>
* gdb.base/dprintf-bp-same-addr.c: New file.
* gdb.base/dprintf-bp-same-addr.exp: New file.
If some event happens to trigger at the same address as a dprintf-style
agent dprintf is installed, GDB will complain, like:
(gdb) continue
Continuing.
May only run agent-printf on the target
(gdb)
Such dprintfs are completely handled on the target side, so they can't
explain a stop, but GDB is currently putting then on the bpstat chain
anyway, because they currently unconditionally use bkpt_breakpoint_hit
as breakpoint_hit method.
gdb/
2014-06-02 Pedro Alves <palves@redhat.com>
* breakpoint.c (dprintf_breakpoint_hit): New function.
(initialize_breakpoint_ops): Install it as dprintf's
breakpoint_hit method.
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.
Without the code portion of the patch, we get these failures:
FAIL: gdb.base/break-unload-file.exp: always-inserted on: break: continue
FAIL: gdb.base/break-unload-file.exp: always-inserted on: hbreak: continue
FAIL: gdb.base/sym-file.exp: stale bkpts: continue to breakpoint: end here
They all looks like random SIGTRAPs:
continue
Continuing.
Program received signal SIGTRAP, Trace/breakpoint trap.
0x0000000000400541 in foo () at ../../../src/gdb/testsuite/gdb.base/break-unload-file.c:21
21 }
(gdb) FAIL: gdb.base/break-unload-file.exp: always-inserted on: break: continue
(This is a regression caused by the remove-symbol-file command
series.)
break-unload-file.exp is about having breakpoints inserted, and then
doing "file". I caught this while writing a test that does "file
PROGRAM", while PROGRAM was already loaded, which internally does
"file" first, because I wanted to force a breakpoint_re_set, but the
test is more explicit in case GDB ever optimizes out that re-set.
The problem is that unloading the file with "file" ends up in
disable_breakpoints_in_freed_objfile, which marks all breakpoint
locations of the objfile as both shlib_disabled, _and_ clears the
inserted flag, without actually removing the breakpoints from the
inferior. Now, usually, in all-stop, breakpoints will already be
removed from the inferior before the user can issue the "file"
command, but, with non-stop, or breakpoints always-inserted on mode,
breakpoints stay inserted even while the user has the prompt. In the
latter case, then, if we let the program continue, and it executes the
address where we had previously set the breakpoint, it'll actually
execute the breakpoint instruction that we left behind...
Now, one issue is that the intent of
disable_breakpoints_in_freed_objfile is really to handle the unloading
of OBJF_USERLOADED objfiles. These are objfiles that were added with
add-symbol-file and that are removed with remove-symbol-file.
"add-symbol-file"'s docs in the manual clearly say these commands are
used to let GDB know about dynamically loaded code:
You would use this command when @var{filename} has been dynamically
loaded (by some other means) into the program that is running.
Similarly, the online help says:
(gdb) help add-symbol-file
Load symbols from FILE, assuming FILE has been dynamically loaded.
So it makes sense to, like when shared libraries are unloaded through
the generic solib machinery, mark the breakpoint locations as
shlib_disabled. But, the "file" command is not about dynamically
loaded code, it's about the main program. So the patch makes
disable_breakpoints_in_freed_objfile skip all objfiles but
OBJF_USERLOADED ones, thus skipping the main objfile.
Then, the reason that disable_breakpoints_in_freed_objfile was
clearing the inserted flag isn't clear, but likely to avoid breakpoint
removal errors, assuming remove-symbol-file was called after the
dynamic object was already unmapped from the inferior. In that case,
it'd okay to simply clear the inserted flag, but not so if the user
for example does remove-symbol-file to remove the library because he
made a mistake in the library's address, and wants to re-do
add-symbol-file with the correct address.
To address all that, I propose an alternative implementation, that
handles both cases. The patch includes changes to sym-file.exp to
cover them.
This implementation leaves the inserted flag alone, and handles
breakpoint insertion/removal failure gracefully when the locations are
in OBJF_USERLOADED objfiles, just like we handle insertion/removal
failure gracefully for locations in shared libraries.
To try to make sure we aren't patching back stale shadow memory
contents into the inferior, in case the program mapped a different
library at the same address where we had the breakpoint, without the
user having had a chance of remove-symbol-file'ing before, this adds a
new memory_validate_breakpoint function that checks if the breakpoint
instruction is still in memory. ppc_linux_memory_remove_breakpoint
does this unconditionally for all memory breakpoints, and questions
whether memory_remove_breakpoint should be changed to do this for all
breakpoints. Possibly yes, though I'm not certain, hence this
baby-steps patch.
Tested on x86_64 Fedora 17, native and gdbserver.
gdb/
2014-04-23 Pedro Alves <palves@redhat.com>
* breakpoint.c (insert_bp_location): Tolerate errors if the
breakpoint is set in a user-loaded objfile.
(remove_breakpoint_1): Likewise. Also tolerate errors if the
location is marked shlib_disabled. If the breakpoint is set in a
user-loaded objfile is a GDB-side memory breakpoint, validate it
before uninsertion. (disable_breakpoints_in_freed_objfile): Skip
non-OBJF_USERLOADED objfiles. Don't clear the location's inserted
flag.
* mem-break.c (memory_validate_breakpoint): New function.
* objfiles.c (userloaded_objfile_contains_address_p): New
function.
* objfiles.h (userloaded_objfile_contains_address_p): Declare.
* target.h (memory_validate_breakpoint): New declaration.
gdb/testsuite/
2014-04-23 Pedro Alves <palves@redhat.com>
* gdb.base/break-unload-file.c: New file.
* gdb.base/break-unload-file.exp: New file.
* gdb.base/sym-file-lib.c (baz): New function.
* gdb.base/sym-file-loader.c (struct segment) <mapped_size>: New
field.
(load): Store the segment's mapped size.
(unload): New function.
(unload_shlib): New function.
* gdb.base/sym-file-loader.h (unload_shlib): New declaration.
* gdb.base/sym-file-main.c (main): Unload, and reload the library,
set a breakpoint at baz, and call it.
* gdb.base/sym-file.exp: New tests for stale breakpoint
instructions.
libraries.
As explained in
https://sourceware.org/ml/gdb-patches/2008-08/msg00361.html, after a
shared library was unloaded, we can no longer insert or remove
breakpoints into/from its (no longer present) code segment. That'll
fail with memory errors. However, that concern does not apply to
hardware breakpoints. By definition, hardware breakpoints are
implemented using a mechanism that is not dependent on being able to
modify the target's memory. Usually, by setting up CPU debug
registers. IOW, we should be able to set hw breakpoints in an
unmapped address. We don't seem to have a test that exercises that,
so this patch adds one.
I noticed the error supression because of a related issue -- the
target_insert_hw_breakpoint/target_remove_hw_breakpoint interfaces
don't really distinguish "not supported" from "error" return, and so
remote.c returns -1 in both cases. This results in hardware
breakpoints set in shared libraries silently ending up pending forever
even though the target doesn't actually support hw breakpoints.
(gdb) set breakpoint always-inserted on
(gdb) set remote Z-packet off
(gdb) info breakpoints
No breakpoints or watchpoints.
(gdb) hbreak shrfunc
Hardware assisted breakpoint 3 at 0x7ffff7dfb657: file ../../../src/gdb/testsuite/gdb.base/hbreak-in-shr-unsupported-shr.c, line 21.
(gdb) info break
Num Type Disp Enb Address What
3 hw breakpoint keep y <PENDING> shrfunc
After the patch we get the expected:
(gdb) hbreak shrfunc
Hardware assisted breakpoint 3 at 0x7ffff7dfb657: file ../../../src/gdb/testsuite/gdb.base/hbreak-in-shr-unsupported-shr.c, line 21.
Warning:
Cannot insert hardware breakpoint 3.
Could not insert hardware breakpoints:
You may have requested too many hardware breakpoints/watchpoints.
(gdb) info break
Num Type Disp Enb Address What
3 hw breakpoint keep y 0x00007ffff7dfb657 in shrfunc at ../../../src/gdb/testsuite/gdb.base/hbreak-in-shr-unsupported-shr.c:21
(HW breakpoints set in the main executable, when the target doesn't
support HW breakpoints always resulted in the latter output.)
We probably should improve the insert/remove interface to return a
different error code for unsupported. But I chose to fix the error
supression first, as it's a deeper and wider issue.
Tested on x86_64 Fedora 17, native and gdbserver.
gdb/
2014-04-23 Pedro Alves <palves@redhat.com>
* breakpoint.c (insert_bp_location, remove_breakpoint_1): If
the breakpoint is set in a shared library, only suppress
errors for software breakpoints, not hardware breakpoints.
gdb/testsuite/
2014-04-23 Pedro Alves <palves@redhat.com>
* gdb.base/hbreak-in-shr-unsupported-shr.c: New file.
* gdb.base/hbreak-in-shr-unsupported.c: New file.
* gdb.base/hbreak-in-shr-unsupported.exp: New file.
* gdb.base/hbreak-unmapped.c: New file.
* gdb.base/hbreak-unmapped.exp: New file.
* gdb.trace/qtro.exp (gdb_is_target_remote): Move ...
* lib/gdb.exp (gdb_is_target_remote): ... here.
Breakpoints are supposed to be transparent to memory accesses. For
all kinds of breakpoints breakpoint_xfer_memory hides the breakpoint
instructions. However, sss breakpoints aren't tracked like all other
breakpoints, and nothing is taking care of hiding them from memory
reads.
Say, as is, a background step + disassemble will see breakpoints
instructions on software step targets. E.g., stepping over this line:
while (1);
with s&
and then "disassemble" would show sss breakpoints.
Actually, that's still not be possible to see today, because:
- in native Linux, you can't read memory while the program
is running.
- with Linux gdbserver, you can, but in the all-stop RSP you
can't talk to the server while the program is running...
- and with non-stop, on software step targets, we presently
force the use of displaced-stepping for all single-steps,
so no single-step breakpoints are used...
I've been working towards making non-stop not force displaced stepping
on sss targets, and I noticed the issue then. With that, I indeed see
this:
(gdb) set remote Z-packet off
(gdb) s&
(gdb) disassemble main
Dump of assembler code for function main:
0x000000000040049c <+0>: push %rbp
0x000000000040049d <+1>: mov %rsp,%rbp
0x00000000004004a0 <+4>: int3
0x00000000004004a1 <+5>: (bad)
End of assembler dump.
Instead of the correct:
(gdb) disassemble main
Dump of assembler code for function main:
0x000000000040049c <+0>: push %rbp
0x000000000040049d <+1>: mov %rsp,%rbp
0x00000000004004a0 <+4>: jmp 0x4004a0 <main+4>
This is actually one thing that my v1 of the recent "fix a bunch of
run control bugs" series was fixing, because it made sss breakpoints
be regular breakpoints in the breakpoint chain. But dropped it in the
version that landed in the tree, due to some problems.
So instead of making sss breakpoints regular breakpoints, go with a
simpler fix (at least for now) -- make breakpoint_xfer_memory take
software single-step breakpoints into account. After the patch, I get
the correct disassemble output.
Tested on x86_64 Fedora 17, and also on top of my "use software
single-step on x86" series.
Also fixes the issue pointed out by Yao at
https://sourceware.org/ml/gdb-patches/2014-04/msg00045.html, where the
prologue analysis/frame sniffing manages to see software step
breakpoint instructions.
gdb/
2014-04-10 Pedro Alves <palves@redhat.com>
* breakpoint.c (single_step_breakpoints)
(single_step_gdbarch): Move up in the file.
(one_breakpoint_xfer_memory): New function, factored out from ...
(breakpoint_xfer_memory): ... here. Also process single-step
breakpoints.
Even with deferred_step_ptid out of the way, GDB can still lose
watchpoints.
If a watchpoint triggers and the PC points to an address where a
thread-specific breakpoint for another thread is set, the thread-hop
code triggers, and we lose the watchpoint:
if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
{
int thread_hop_needed = 0;
struct address_space *aspace =
get_regcache_aspace (get_thread_regcache (ecs->ptid));
/* Check if a regular breakpoint has been hit before checking
for a potential single step breakpoint. Otherwise, GDB will
not see this breakpoint hit when stepping onto breakpoints. */
if (regular_breakpoint_inserted_here_p (aspace, stop_pc))
{
if (!breakpoint_thread_match (aspace, stop_pc, ecs->ptid))
thread_hop_needed = 1;
^^^^^^^^^^^^^^^^^^^^^
}
And on software single-step targets, even without a thread-specific
breakpoint in the way, here in the thread-hop code:
else if (singlestep_breakpoints_inserted_p)
{
...
if (!ptid_equal (singlestep_ptid, ecs->ptid)
&& in_thread_list (singlestep_ptid))
{
/* If the PC of the thread we were trying to single-step
has changed, discard this event (which we were going
to ignore anyway), and pretend we saw that thread
trap. This prevents us continuously moving the
single-step breakpoint forward, one instruction at a
time. If the PC has changed, then the thread we were
trying to single-step has trapped or been signalled,
but the event has not been reported to GDB yet.
There might be some cases where this loses signal
information, if a signal has arrived at exactly the
same time that the PC changed, but this is the best
we can do with the information available. Perhaps we
should arrange to report all events for all threads
when they stop, or to re-poll the remote looking for
this particular thread (i.e. temporarily enable
schedlock). */
CORE_ADDR new_singlestep_pc
= regcache_read_pc (get_thread_regcache (singlestep_ptid));
if (new_singlestep_pc != singlestep_pc)
{
enum gdb_signal stop_signal;
if (debug_infrun)
fprintf_unfiltered (gdb_stdlog, "infrun: unexpected thread,"
" but expected thread advanced also\n");
/* The current context still belongs to
singlestep_ptid. Don't swap here, since that's
the context we want to use. Just fudge our
state and continue. */
stop_signal = ecs->event_thread->suspend.stop_signal;
ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
ecs->ptid = singlestep_ptid;
ecs->event_thread = find_thread_ptid (ecs->ptid);
ecs->event_thread->suspend.stop_signal = stop_signal;
stop_pc = new_singlestep_pc;
}
else
{
if (debug_infrun)
fprintf_unfiltered (gdb_stdlog,
"infrun: unexpected thread\n");
thread_hop_needed = 1;
stepping_past_singlestep_breakpoint = 1;
saved_singlestep_ptid = singlestep_ptid;
}
}
}
we either end up with thread_hop_needed, ignoring the watchpoint
SIGTRAP, or switch to the stepping thread, again ignoring that the
SIGTRAP could be for some other event.
The new test added by this patch exercises both paths.
So the fix is similar to the deferred_step_ptid fix -- defer the
thread hop to _after_ the SIGTRAP had a change of passing through the
regular bpstat handling. If the wrong thread hits a breakpoint, we'll
just end up with BPSTAT_WHAT_SINGLE, and if nothing causes a stop,
keep_going starts a step-over.
Most of the stepping_past_singlestep_breakpoint mechanism is really
not necessary -- setting the thread to step over a breakpoint with
thread->trap_expected is sufficient to keep all other threads locked.
It's best to still keep the flag in some form though, because when we
get to keep_going, the software single-step breakpoint we need to step
over is already gone -- an optimization done by a follow up patch will
check whether a step-over is still be necessary by looking to see
whether the breakpoint is still there, and would find the thread no
longer needs a step-over, while we still want it.
Special care is still needed to handle the case of PC of the thread we
were trying to single-step having changed, like in the old code. We
can't just keep_going and re-step it, as in that case we can over-step
the thread (if it was already done with the step, but hasn't reported
it yet, we'd ask it to step even further). That's now handled in
switch_back_to_stepped_thread. As bonus, we're now using a technique
that doesn't lose signals, unlike the old code -- we now insert a
breakpoint at PC, and resume, which either reports the breakpoint
immediately, or any pending signal.
Tested on x86_64 Fedora 17, against pristine mainline, and against a
branch that implements software single-step on x86.
gdb/
2014-03-20 Pedro Alves <palves@redhat.com>
* breakpoint.c (single_step_breakpoint_inserted_here_p): Make
extern.
* breakpoint.h (single_step_breakpoint_inserted_here_p): Declare.
* infrun.c (saved_singlestep_ptid)
(stepping_past_singlestep_breakpoint): Delete.
(resume): Remove stepping_past_singlestep_breakpoint handling.
(proceed): Store the prev_pc of the stepping thread too.
(init_wait_for_inferior): Adjust. Clear singlestep_ptid and
singlestep_pc.
(enum infwait_states): Delete infwait_thread_hop_state.
(struct execution_control_state) <hit_singlestep_breakpoint>: New
field.
(handle_inferior_event): Adjust.
(handle_signal_stop): Delete stepping_past_singlestep_breakpoint
handling and the thread-hop code. Before removing single-step
breakpoints, check whether the thread hit a single-step breakpoint
of another thread. If it did, the trap is not a random signal.
(switch_back_to_stepped_thread): If the event thread hit a
single-step breakpoint, unblock it before switching to the
stepping thread. Handle the case of the stepped thread having
advanced already.
(keep_going): Handle the case of the current thread moving past a
single-step breakpoint.
gdb/testsuite/
2014-03-20 Pedro Alves <palves@redhat.com>
* gdb.threads/step-over-trips-on-watchpoint.c: New file.
* gdb.threads/step-over-trips-on-watchpoint.exp: New file.
Say the program is stopped at a breakpoint, and the user sets a
watchpoint. When the program is next resumed, GDB will first step
over the breakpoint, as explained in the manual:
@value {GDBN} normally ignores breakpoints when it resumes
execution, until at least one instruction has been executed. If it
it did not do this, you would be unable to proceed past a breakpoint
without first disabling the breakpoint. This rule applies whether
or not the breakpoint already existed when your program stopped.
However, GDB currently also removes watchpoints, catchpoints, etc.,
and that means that the first instruction off the breakpoint does not
trigger the watchpoint, catchpoint, etc.
testsuite/gdb.base/watchpoint.exp has a kfail for this.
The PR proposes installing watchpoints only when stepping over a
breakpoint, but that misses catchpoints, etc.
A better fix would instead work from the opposite direction -- remove
only real breakpoints, leaving all other kinds of breakpoints
inserted.
But, going further, it's really a waste to constantly remove/insert
all breakpoints when stepping over a single breakpoint (generating a
pair of RSP z/Z packets for each breakpoint), so the fix goes a step
further and makes GDB remove _only_ the breakpoint being stepped over,
leaving all others installed. This then has the added benefit of
reducing breakpoint-related RSP traffic substancialy when there are
many breakpoints set.
gdb/
2014-03-20 Pedro Alves <palves@redhat.com>
PR breakpoints/7143
* breakpoint.c (should_be_inserted): Don't insert breakpoints that
are being stepped over.
(breakpoint_address_match): Make extern.
* breakpoint.h (breakpoint_address_match): New declaration.
* inferior.h (stepping_past_instruction_at): New declaration.
* infrun.c (struct step_over_info): New type.
(step_over_info): New global.
(set_step_over_info, clear_step_over_info)
(stepping_past_instruction_at): New functions.
(handle_inferior_event): Clear the step-over info when
trap_expected is cleared.
(resume): Remove now stale comment.
(clear_proceed_status): Clear step-over info.
(proceed): Adjust step-over handling to set or clear the step-over
info instead of removing all breakpoints.
(handle_signal_stop): When setting up a thread-hop, don't remove
breakpoints here.
(stop_stepping): Clear step-over info.
(keep_going): Adjust step-over handling to set or clear step-over
info and then always inserting breakpoints, instead of removing
all breakpoints when stepping over one.
gdb/testsuite/
2014-03-20 Pedro Alves <palves@redhat.com>
PR breakpoints/7143
* gdb.base/watchpoint.exp: Mention bugzilla bug number instead of
old gnats gdb/38. Remove kfail. Adjust to use gdb_test instead
of gdb_test_multiple.
* gdb.cp/annota2.exp: Remove kfail for gdb/38.
* gdb.cp/annota3.exp: Remove kfail for gdb/38.
This patch is to remove parameter optional_p as it is always true,
in order to simplify get_tracepoint_by_number.
'optional_p' was added by this change,
1999-11-18 Tom Tromey <tromey@cygnus.com>
* tracepoint.h (get_tracepoint_by_number): Updated
declaration.
* tracepoint.c (trace_pass_command): Better error message.
Fixed logic when `all' not specified.
(get_tracepoint_by_number): Added `optional_p' argument. Fixed
all callers.
but after this patch,
FYI: remove `static's from cli-utils.c
https://sourceware.org/ml/gdb-patches/2011-03/msg00636.html
'optional_p' passed to get_tracepoint_by_number become always true.
gdb:
2014-03-06 Yao Qi <yao@codesourcery.com>
* breakpoint.c (get_tracepoint_by_number): Remove argument
optional_p. All callers updated. Adjust comments. Update
output message.
* breakpoint.h (get_tracepoint_by_number): Update declaration.
This changes the probes to be independent of the program space.
After this, when a probe's address is needed, it is determined by
applying offsets at the point of use.
This introduces a bound_probe object, similar to bound minimal
symbols. Objects of this type are used when it's necessary to pass a
probe and its corresponding objfile.
This removes the backlink from probe to objfile, which was primarily
used to fetch the architecture to use.
This adds a get_probe_address function which calls a probe method to
compute the probe's relocated address. Similarly, it adds an objfile
parameter to the semaphore methods so they can do the relocation
properly as well.
2014-03-03 Tom Tromey <tromey@redhat.com>
* break-catch-throw.c (fetch_probe_arguments): Use bound probes.
* breakpoint.c (create_longjmp_master_breakpoint): Use
get_probe_address.
(add_location_to_breakpoint, bkpt_probe_insert_location)
(bkpt_probe_remove_location): Update.
* breakpoint.h (struct bp_location) <probe>: Now a bound_probe.
* elfread.c (elf_symfile_relocate_probe): Remove.
(elf_probe_fns): Update.
(insert_exception_resume_breakpoint): Change type of "probe"
parameter to bound_probe.
(check_exception_resume): Update.
* objfiles.c (objfile_relocate1): Don't relocate probes.
* probe.c (bound_probe_s): New typedef.
(parse_probes): Use get_probe_address. Set sal's objfile.
(find_probe_by_pc): Return a bound_probe.
(collect_probes): Return a VEC(bound_probe_s).
(compare_probes): Update.
(gen_ui_out_table_header_info): Change type of "probes"
parameter. Update.
(info_probes_for_ops): Update.
(get_probe_address): New function.
(probe_safe_evaluate_at_pc): Update.
* probe.h (struct probe_ops) <get_probe_address>: New field.
<set_semaphore, clear_semaphore>: Add objfile parameter.
(struct probe) <objfile>: Remove field.
<arch>: New field.
<address>: Update comment.
(struct bound_probe): New.
(find_probe_by_pc): Return a bound_probe.
(get_probe_address): Declare.
* solib-svr4.c (struct probe_and_action) <address>: New field.
(hash_probe_and_action, equal_probe_and_action): Update.
(register_solib_event_probe): Add address parameter.
(solib_event_probe_at): Update.
(svr4_create_probe_breakpoints): Add objfile parameter. Use
get_probe_address.
* stap-probe.c (struct stap_probe) <sem_addr>: Update comment.
(stap_get_probe_address): New function.
(stap_can_evaluate_probe_arguments, compute_probe_arg)
(compile_probe_arg): Update.
(stap_set_semaphore, stap_clear_semaphore): Compute semaphore's
address.
(handle_stap_probe): Don't relocate the probe.
(stap_relocate): Remove.
(stap_gen_info_probes_table_values): Update.
(stap_probe_ops): Remove stap_relocate.
* symfile-debug.c (debug_sym_relocate_probe): Remove.
(debug_sym_probe_fns): Update.
* symfile.h (struct sym_probe_fns) <sym_relocate_probe>: Remove.
* symtab.c (init_sal): Use memset.
* symtab.h (struct symtab_and_line) <objfile>: New field.
* tracepoint.c (start_tracing, stop_tracing): Update.
With the test changed as in the patch, against current mainline, we get:
(gdb) PASS: gdb.ada/tasks.exp: info tasks before inserting breakpoint
break break_me task 1
Breakpoint 2 at 0x4030b0: file /home/pedro/gdb/mygit/src/gdb/testsuite/gdb.ada/tasks/foo.adb, line 27.
(gdb) PASS: gdb.ada/tasks.exp: break break_me task 1
break break_me task 3
Note: breakpoint 2 also set at pc 0x4030b0.
Breakpoint 3 at 0x4030b0: file /home/pedro/gdb/mygit/src/gdb/testsuite/gdb.ada/tasks/foo.adb, line 27.
(gdb) PASS: gdb.ada/tasks.exp: break break_me task 3
continue
Continuing.
[Switching to Thread 0x7ffff7dc7700 (LWP 27133)]
Breakpoint 2, foo.break_me () at /home/pedro/gdb/mygit/src/gdb/testsuite/gdb.ada/tasks/foo.adb:27
27 null;
(gdb) FAIL: gdb.ada/tasks.exp: continue to breakpoint
info tasks
ID TID P-ID Pri State Name
1 63b010 48 Waiting on RV with 3 main_task
2 63bd80 1 48 Accept or Select Term task_list(1)
* 3 63f510 1 48 Accepting RV with 1 task_list(2)
4 642ca0 1 48 Accept or Select Term task_list(3)
(gdb) PASS: gdb.ada/tasks.exp: info tasks after hitting breakpoint
The breakpoint that caused a stop is breakpoint 3, but GDB end up
reporting (and running breakpoint commands of) "Breakpoint 2" instead.
The issue is that the bpstat_check_breakpoint_conditions logic of
"wrong thread" is missing the "wrong task" check. This is usually
harmless, because the thread hop code in infrun.c code that handles
wrong-task-hitting-breakpoint does check for task-specific breakpoints
(within breakpoint_thread_match):
/* Check if a regular breakpoint has been hit before checking
for a potential single step breakpoint. Otherwise, GDB will
not see this breakpoint hit when stepping onto breakpoints. */
if (regular_breakpoint_inserted_here_p (aspace, stop_pc))
{
if (!breakpoint_thread_match (aspace, stop_pc, ecs->ptid))
thread_hop_needed = 1;
}
IOW, usually, when one only has a task specific breakpoint at a given
address, things work correctly. Put another task-specific or
non-task-specific breakpoint there, and things break.
A patch that eliminates the special thread hop code in infrun.c is
what exposed this, as after that GDB solely relies on
bpstat_check_breakpoint_conditions to know whether the right or wrong
task hit a breakpoint. IOW, given the latent bug, Ada task-specific
breakpoints become non-task-specific, and that is caught by the
testsuite, as:
break break_me task 3
Breakpoint 2 at 0x4030b0: file /home/pedro/gdb/mygit/src/gdb/testsuite/gdb.ada/tasks/foo.adb, line 27.
(gdb) PASS: gdb.ada/tasks.exp: break break_me task 3
continue
Continuing.
[Switching to Thread 0x7ffff7fcb700 (LWP 17122)]
Breakpoint 2, foo.break_me () at /home/pedro/gdb/mygit/src/gdb/testsuite/gdb.ada/tasks/foo.adb:27
27 null;
(gdb) PASS: gdb.ada/tasks.exp: continue to breakpoint
info tasks
ID TID P-ID Pri State Name
1 63b010 48 Waiting on RV with 2 main_task
* 2 63bd80 1 48 Accepting RV with 1 task_list(1)
3 63f510 1 48 Accept or Select Term task_list(2)
4 642ca0 1 48 Accept or Select Term task_list(3)
(gdb) FAIL: gdb.ada/tasks.exp: info tasks after hitting breakpoint
It was after seeing this that I thought of how to expose the bug with
current mainline.
Tested on x86_64 Fedora 17.
gdb/
2014-02-26 Pedro Alves <palves@redhat.com>
* breakpoint.c (bpstat_check_breakpoint_conditions): Handle
task-specific breakpoints.
gdb/testsuite/
2014-02-26 Pedro Alves <palves@redhat.com>
* gdb.ada/tasks.exp: Set a task-specific breakpoint at break_me
that won't ever trigger. Make sure that GDB reports the correct
breakpoint that caused the stop.
* configure.ac (libpython checking): Remove all but python.o from
CONFIG_OBS. Remove all but python.c from CONFIG_SRCS.
* configure: Regenerate.
* Makefile.in (SFILES): Add extension.c.
(HFILES_NO_SRCDIR): Add extension.h, extension-priv.h
(COMMON_OBS): Add extension.o.
* extension.h: New file.
* extension-priv.h: New file.
* extension.c: New file.
* python/python-internal.h: #include "extension.h".
(gdbpy_auto_load_enabled): Declare.
(gdbpy_apply_val_pretty_printer): Declare.
(gdbpy_apply_frame_filter): Declare.
(gdbpy_preserve_values): Declare.
(gdbpy_breakpoint_cond_says_stop): Declare.
(gdbpy_breakpoint_has_cond): Declare.
(void source_python_script_for_objfile): Delete.
* python/python.c: #include "extension-priv.h".
Delete inclusion of "observer.h".
(extension_language_python): Moved here and renamed from
script_language_python in py-auto-load.c.
Redefined to be of type extension_language_defn.
(python_extension_script_ops): New global.
(python_extension_ops): New global.
(struct python_env): New member previous_active.
(restore_python_env): Call restore_active_ext_lang.
(ensure_python_env): Call set_active_ext_lang.
(gdbpy_clear_quit_flag): Renamed from clear_quit_flag, made static.
New arg extlang.
(gdbpy_set_quit_flag): Renamed from set_quit_flag, made static.
New arg extlang.
(gdbpy_check_quit_flag): Renamed from check_quit_flag, made static.
New arg extlang.
(gdbpy_eval_from_control_command): Renamed from
eval_python_from_control_command, made static. New arg extlang.
(gdbpy_source_script) Renamed from source_python_script, made static.
New arg extlang.
(gdbpy_before_prompt_hook): Renamed from before_prompt_hook. Change
result to int. New arg extlang.
(gdbpy_source_objfile_script): Renamed from
source_python_script_for_objfile, made static. New arg extlang.
(gdbpy_start_type_printers): Renamed from start_type_printers, made
static. New args extlang, extlang_printers. Change result type to
"void".
(gdbpy_apply_type_printers): Renamed from apply_type_printers, made
static. New arg extlang. Rename arg printers to extlang_printers
and change type to ext_lang_type_printers *.
(gdbpy_free_type_printers): Renamed from free_type_printers, made
static. Replace argument arg with extlang, extlang_printers.
(!HAVE_PYTHON, eval_python_from_control_command): Delete.
(!HAVE_PYTHON, source_python_script): Delete.
(!HAVE_PYTHON, gdbpy_should_stop): Delete.
(!HAVE_PYTHON, gdbpy_breakpoint_has_py_cond): Delete.
(!HAVE_PYTHON, start_type_printers): Delete.
(!HAVE_PYTHON, apply_type_printers): Delete.
(!HAVE_PYTHON, free_type_printers): Delete.
(_initialize_python): Delete call to observer_attach_before_prompt.
(finalize_python): Set/restore active extension language.
(gdbpy_finish_initialization) Renamed from
finish_python_initialization, made static. New arg extlang.
(gdbpy_initialized): New function.
* python/python.h: #include "extension.h". Delete #include
"value.h", "mi/mi-cmds.h".
(extension_language_python): Declare.
(GDBPY_AUTO_FILE_NAME): Delete.
(enum py_bt_status): Moved to extension.h and renamed to
ext_lang_bt_status.
(enum frame_filter_flags): Moved to extension.h.
(enum py_frame_args): Moved to extension.h and renamed to
ext_lang_frame_args.
(finish_python_initialization): Delete.
(eval_python_from_control_command): Delete.
(source_python_script): Delete.
(apply_val_pretty_printer): Delete.
(apply_frame_filter): Delete.
(preserve_python_values): Delete.
(gdbpy_script_language_defn): Delete.
(gdbpy_should_stop, gdbpy_breakpoint_has_py_cond): Delete.
(start_type_printers, apply_type_printers, free_type_printers): Delete.
* auto-load.c: #include "extension.h".
(GDB_AUTO_FILE_NAME): Delete.
(auto_load_gdb_scripts_enabled): Make public. New arg extlang.
(script_language_gdb): Delete, moved to extension.c and renamed to
extension_language_gdb.
(source_gdb_script_for_objfile): Delete.
(auto_load_pspace_info): New member unsupported_script_warning_printed.
(loaded_script): Change type of language member to
struct extension_language_defn *.
(init_loaded_scripts_info): Initialize
unsupported_script_warning_printed.
(maybe_add_script): Make static. Change type of language arg to
struct extension_language_defn *.
(clear_section_scripts): Reset unsupported_script_warning_printed.
(auto_load_objfile_script_1): Rewrite to use extension language API.
(auto_load_objfile_script): Make public. Remove support-compiled-in
and auto-load-enabled checks, moved to auto_load_scripts_for_objfile.
(source_section_scripts): Rewrite to use extension language API.
(load_auto_scripts_for_objfile): Rewrite to use
auto_load_scripts_for_objfile.
(collect_matching_scripts_data): Change type of language member to
struct extension_language_defn *.
(auto_load_info_scripts): Change type of language arg to
struct extension_language_defn *.
(unsupported_script_warning_print): New function.
(script_not_found_warning_print): Make static.
(_initialize_auto_load): Rewrite construction of scripts-directory
help.
* auto-load.h (struct objfile): Add forward decl.
(struct script_language): Delete.
(struct auto_load_pspace_info): Add forward decl.
(struct extension_language_defn): Add forward decl.
(maybe_add_script): Delete.
(auto_load_objfile_script): Declare.
(script_not_found_warning_print): Delete.
(auto_load_info_scripts): Update prototype.
(auto_load_gdb_scripts_enabled): Declare.
* python/py-auto-load.c (gdbpy_auto_load_enabled): Renamed from
auto_load_python_scripts_enabled and made public.
(script_language_python): Delete, moved to python.c.
(gdbpy_script_language_defn): Delete.
(info_auto_load_python_scripts): Update to use
extension_language_python.
* breakpoint.c (condition_command): Replace call to
gdbpy_breakpoint_has_py_cond with call to get_breakpoint_cond_ext_lang.
(bpstat_check_breakpoint_conditions): Replace call to gdbpy_should_stop
with call to breakpoint_ext_lang_cond_says_stop.
* python/py-breakpoint.c (gdbpy_breakpoint_cond_says_stop): Renamed
from gdbpy_should_stop. Change result type to enum scr_bp_stop.
New arg slang. Return SCR_BP_STOP_UNSET if py_bp_object is NULL.
(gdbpy_breakpoint_has_cond): Renamed from gdbpy_breakpoint_has_py_cond.
New arg slang.
(local_setattro): Print name of extension language with existing
stop condition.
* valprint.c (val_print, value_print): Update to call
apply_ext_lang_val_pretty_printer.
* cp-valprint.c (cp_print_value): Update call to
apply_ext_lang_val_pretty_printer.
* python/py-prettyprint.c: Remove #ifdef HAVE_PYTHON.
(gdbpy_apply_val_pretty_printer): Renamed from
apply_val_pretty_printer. New arg extlang.
(!HAVE_PYTHON, apply_val_pretty_printer): Delete.
* cli/cli-cmds.c (source_script_from_stream): Rewrite to use
extension language API.
* cli/cli-script.c (execute_control_command): Update to call
eval_ext_lang_from_control_command.
* mi/mi-cmd-stack.c (mi_cmd_stack_list_frames): Update to use
enum ext_lang_bt_status values. Update call to
apply_ext_lang_frame_filter.
(mi_cmd_stack_list_locals): Ditto.
(mi_cmd_stack_list_args): Ditto.
(mi_cmd_stack_list_variables): Ditto.
* mi/mi-main.c: Delete #include "python/python-internal.h".
Add #include "extension.h".
(mi_cmd_list_features): Replace reference to python internal variable
gdb_python_initialized with call to ext_lang_initialized_p.
* stack.c (backtrace_command_1): Update to use enum ext_lang_bt_status.
Update to use enum ext_lang_frame_args. Update to call
apply_ext_lang_frame_filter.
* python/py-framefilter.c (extract_sym): Update to use enum
ext_lang_bt_status.
(extract_value, py_print_type, py_print_value): Ditto.
(py_print_single_arg, enumerate_args, enumerate_locals): Ditto.
(py_mi_print_variables, py_print_locals, py_print_args): Ditto.
(py_print_frame): Ditto.
(gdbpy_apply_frame_filter): Renamed from apply_frame_filter.
New arg extlang. Update to use enum ext_lang_bt_status.
* top.c (gdb_init): Delete #ifdef HAVE_PYTHON call to
finish_python_initialization. Replace with call to
finish_ext_lang_initialization.
* typeprint.c (do_free_global_table): Update to call
free_ext_lang_type_printers.
(create_global_typedef_table): Update to call
start_ext_lang_type_printers.
(find_global_typedef): Update to call apply_ext_lang_type_printers.
* typeprint.h (struct ext_lang_type_printers): Add forward decl.
(type_print_options): Change type of global_printers from "void *"
to "struct ext_lang_type_printers *".
* value.c (preserve_values): Update to call preserve_ext_lang_values.
* python/py-value.c: Remove #ifdef HAVE_PYTHON.
(gdbpy_preserve_values): Renamed from preserve_python_values.
New arg extlang.
(!HAVE_PYTHON, preserve_python_values): Delete.
* utils.c (quit_flag): Delete, moved to extension.c.
(clear_quit_flag, set_quit_flag, check_quit_flag): Delete, moved to
extension.c.
* eval.c: Delete #include "python/python.h".
* main.c: Delete #include "python/python.h".
* defs.h: Update comment.
testsuite/
* gdb.python/py-breakpoint.exp (test_bkpt_eval_funcs): Update expected
output.
* gdb.gdb/python-interrupts.exp: New file.
While doing something else, I found that those 2 places were incorrectly
declaring a "struct gdb_exception" without using the "volatile" keyword.
This commit fixes that.
2014-01-17 Sergio Durigan Junior <sergiodj@redhat.com>
* breakpoint.c (insert_bp_location): Add "volatile" keyword to "struct
gdb_exception" declaration.
* remote.c (getpkt_or_notif_sane): Likewise.
Although we can tell upfront whether a remote target supports target
side commands, we can only tell whether the target supports that in
combination with a given breakpoint kind (software, hardware,
watchpoints, etc.) when we go and try to insert such a breakpoint kind
the first time. It's not desirable to make remote_insert_breakpoint
simply return -1 in this case, because if the breakpoint was set in a
shared library, insert_bp_location will assume that the breakpoint
insertion failed because the library wasn't mapped in.
insert_bp_location already handles errors/exceptions thrown from the
target_insert_xxx methods, exactly so the backend can tell the user
the detailed reason the insertion of hw breakpoints failed. But, in
the case of software breakpoints, it discards the detailed error
message.
So the patch makes insert_bp_location use the error's message for SW
breakpoints too, and, introduces a NOT_SUPPORTED_ERROR error code so
that insert_bp_location doesn't confuse the error for failure due to a
shared library disappearing.
The result is:
(gdb) c
Warning:
Cannot insert breakpoint 2: Target doesn't support breakpoints that have target side commands.
2014-01-09 Pedro Alves <palves@redhat.com>
Hui Zhu <hui@codesourcery.com>
PR gdb/16101
* breakpoint.c (insert_bp_location): Rename hw_bp_err_string to
bp_err_string. Don't mark the location shlib_disabled if the
error thrown wasn't a generic or memory error. Catch errors
thrown while inserting breakpoints in overlayed code. Output
error message of software breakpoints.
* remote.c (remote_insert_breakpoint): If this breakpoint has
target-side commands but this stub doesn't support Z0 packets,
throw NOT_SUPPORTED_ERROR error.
* exceptions.h (enum errors) <NOT_SUPPORTED_ERROR>: New error.
* target.h (target_insert_breakpoint): Extend comment.
(target_insert_hw_breakpoint): Add comment.
Code rationale
==============
by: Gabriel Krisman Bertazi
This is a fix for bug 16297. The problem occurs when the user attempts
to catch any syscall 0 (such as syscall read on Linux/x86_64). GDB was
not able to catch the syscall and was missing the breakpoint.
Now, breakpoint_hit_catch_syscall returns immediately when it finds the
correct syscall number, avoiding a following check for the end of the
search vector, that returns a no hit if the syscall number was zero.
Testcase rationale
==================
by: Sergio Durigan Junior
This testcase is a little difficult to write. By doing a quick
inspection at the Linux source, one can see that, in many targets, the
syscall number 0 is restart_syscall, which is forbidden to be called
from userspace. Therefore, on many targets, there's just no way to test
this safely.
My decision was to take the simpler route and just adds the "read"
syscall on the default test. Its number on x86_64 is zero, which is
"good enough" since many people here do their tests on x86_64 anyway and
it is a popular architecture.
However, there was another little gotcha. When using "read" passing 0
as the third parameter (i.e., asking it to read 0 bytes), current libc
implementations could choose not to effectively call the syscall.
Therefore, the best solution was to create a temporary pipe, write 1
byte into it, and then read this byte from it.
gdb/ChangeLog
2013-12-19 Gabriel Krisman Bertazi <gabriel@krisman.be>
PR breakpoints/16297
* breakpoint.c (breakpoint_hit_catch_syscall): Return immediately
when expected syscall is hit.
gdb/testsuite/ChangeLog
2013-12-19 Sergio Durigan Junior <sergiodj@redhat.com>
PR breakpoints/16297
* gdb.base/catch-syscall.c (read_syscall, pipe_syscall)
(write_syscall): New variables.
(main): Create a pipe, write 1 byte in it, and read 1 byte from
it.
* gdb.base/catch-syscall.exp (all_syscalls): Include "pipe,
"write" and "read" syscalls.
(fill_all_syscalls_numbers): Improve the way to obtain syscalls
numbers.
The memory management of bp_location->target_info.conditions|tcommands
is currently a little fragile. If the target reports support for
target conditions or commands, and then target side breakpoint support
is disabled, or some error is thrown before remote_add_target_side_XXX
is called, we'll leak these lists. This patch makes us free these
lists when the locations are deleted, and also, just before recreating
the commands|conditions lists.
Tested on x86_64 Fedora 17, native and gdbserver.
gdb/
2013-11-29 Pedro Alves <palves@redhat.com>
* breakpoint.c (build_target_condition_list): Release previous
conditions.
(build_target_command_list): Release previous commands.
(bp_location_dtor): Release target conditions and commands.
* remote.c (remote_add_target_side_condition): Don't release
conditions.
(remote_add_target_side_commands): Don't release commands.
This removes gdb_string.h. This patch is purely mechanical. I
created it by running the two commands:
git rm common/gdb_string.h
perl -pi -e's/"gdb_string.h"/<string.h>/;' *.[chyl] */*.[chyl]
2013-11-18 Tom Tromey <tromey@redhat.com>
* common/gdb_string.h: Remove.
* aarch64-tdep.c: Use string.h, not gdb_string.h.
* ada-exp.y: Use string.h, not gdb_string.h.
* ada-lang.c: Use string.h, not gdb_string.h.
* ada-lex.l: Use string.h, not gdb_string.h.
* ada-typeprint.c: Use string.h, not gdb_string.h.
* ada-valprint.c: Use string.h, not gdb_string.h.
* aix-thread.c: Use string.h, not gdb_string.h.
* alpha-linux-tdep.c: Use string.h, not gdb_string.h.
* alpha-mdebug-tdep.c: Use string.h, not gdb_string.h.
* alpha-nat.c: Use string.h, not gdb_string.h.
* alpha-osf1-tdep.c: Use string.h, not gdb_string.h.
* alpha-tdep.c: Use string.h, not gdb_string.h.
* alphanbsd-tdep.c: Use string.h, not gdb_string.h.
* amd64-dicos-tdep.c: Use string.h, not gdb_string.h.
* amd64-linux-nat.c: Use string.h, not gdb_string.h.
* amd64-linux-tdep.c: Use string.h, not gdb_string.h.
* amd64-nat.c: Use string.h, not gdb_string.h.
* amd64-sol2-tdep.c: Use string.h, not gdb_string.h.
* amd64fbsd-tdep.c: Use string.h, not gdb_string.h.
* amd64obsd-tdep.c: Use string.h, not gdb_string.h.
* arch-utils.c: Use string.h, not gdb_string.h.
* arm-linux-nat.c: Use string.h, not gdb_string.h.
* arm-linux-tdep.c: Use string.h, not gdb_string.h.
* arm-tdep.c: Use string.h, not gdb_string.h.
* arm-wince-tdep.c: Use string.h, not gdb_string.h.
* armbsd-tdep.c: Use string.h, not gdb_string.h.
* armnbsd-nat.c: Use string.h, not gdb_string.h.
* armnbsd-tdep.c: Use string.h, not gdb_string.h.
* armobsd-tdep.c: Use string.h, not gdb_string.h.
* avr-tdep.c: Use string.h, not gdb_string.h.
* ax-gdb.c: Use string.h, not gdb_string.h.
* ax-general.c: Use string.h, not gdb_string.h.
* bcache.c: Use string.h, not gdb_string.h.
* bfin-tdep.c: Use string.h, not gdb_string.h.
* breakpoint.c: Use string.h, not gdb_string.h.
* build-id.c: Use string.h, not gdb_string.h.
* buildsym.c: Use string.h, not gdb_string.h.
* c-exp.y: Use string.h, not gdb_string.h.
* c-lang.c: Use string.h, not gdb_string.h.
* c-typeprint.c: Use string.h, not gdb_string.h.
* c-valprint.c: Use string.h, not gdb_string.h.
* charset.c: Use string.h, not gdb_string.h.
* cli-out.c: Use string.h, not gdb_string.h.
* cli/cli-cmds.c: Use string.h, not gdb_string.h.
* cli/cli-decode.c: Use string.h, not gdb_string.h.
* cli/cli-dump.c: Use string.h, not gdb_string.h.
* cli/cli-interp.c: Use string.h, not gdb_string.h.
* cli/cli-logging.c: Use string.h, not gdb_string.h.
* cli/cli-script.c: Use string.h, not gdb_string.h.
* cli/cli-setshow.c: Use string.h, not gdb_string.h.
* cli/cli-utils.c: Use string.h, not gdb_string.h.
* coffread.c: Use string.h, not gdb_string.h.
* common/common-utils.c: Use string.h, not gdb_string.h.
* common/filestuff.c: Use string.h, not gdb_string.h.
* common/linux-procfs.c: Use string.h, not gdb_string.h.
* common/linux-ptrace.c: Use string.h, not gdb_string.h.
* common/signals.c: Use string.h, not gdb_string.h.
* common/vec.h: Use string.h, not gdb_string.h.
* core-regset.c: Use string.h, not gdb_string.h.
* corefile.c: Use string.h, not gdb_string.h.
* corelow.c: Use string.h, not gdb_string.h.
* cp-abi.c: Use string.h, not gdb_string.h.
* cp-support.c: Use string.h, not gdb_string.h.
* cp-valprint.c: Use string.h, not gdb_string.h.
* cris-tdep.c: Use string.h, not gdb_string.h.
* d-lang.c: Use string.h, not gdb_string.h.
* dbxread.c: Use string.h, not gdb_string.h.
* dcache.c: Use string.h, not gdb_string.h.
* demangle.c: Use string.h, not gdb_string.h.
* dicos-tdep.c: Use string.h, not gdb_string.h.
* disasm.c: Use string.h, not gdb_string.h.
* doublest.c: Use string.h, not gdb_string.h.
* dsrec.c: Use string.h, not gdb_string.h.
* dummy-frame.c: Use string.h, not gdb_string.h.
* dwarf2-frame.c: Use string.h, not gdb_string.h.
* dwarf2loc.c: Use string.h, not gdb_string.h.
* dwarf2read.c: Use string.h, not gdb_string.h.
* elfread.c: Use string.h, not gdb_string.h.
* environ.c: Use string.h, not gdb_string.h.
* eval.c: Use string.h, not gdb_string.h.
* event-loop.c: Use string.h, not gdb_string.h.
* exceptions.c: Use string.h, not gdb_string.h.
* exec.c: Use string.h, not gdb_string.h.
* expprint.c: Use string.h, not gdb_string.h.
* f-exp.y: Use string.h, not gdb_string.h.
* f-lang.c: Use string.h, not gdb_string.h.
* f-typeprint.c: Use string.h, not gdb_string.h.
* f-valprint.c: Use string.h, not gdb_string.h.
* fbsd-nat.c: Use string.h, not gdb_string.h.
* findcmd.c: Use string.h, not gdb_string.h.
* findvar.c: Use string.h, not gdb_string.h.
* fork-child.c: Use string.h, not gdb_string.h.
* frame.c: Use string.h, not gdb_string.h.
* frv-linux-tdep.c: Use string.h, not gdb_string.h.
* frv-tdep.c: Use string.h, not gdb_string.h.
* gdb.c: Use string.h, not gdb_string.h.
* gdb_bfd.c: Use string.h, not gdb_string.h.
* gdbarch.c: Use string.h, not gdb_string.h.
* gdbtypes.c: Use string.h, not gdb_string.h.
* gnu-nat.c: Use string.h, not gdb_string.h.
* gnu-v2-abi.c: Use string.h, not gdb_string.h.
* gnu-v3-abi.c: Use string.h, not gdb_string.h.
* go-exp.y: Use string.h, not gdb_string.h.
* go-lang.c: Use string.h, not gdb_string.h.
* go32-nat.c: Use string.h, not gdb_string.h.
* hppa-hpux-tdep.c: Use string.h, not gdb_string.h.
* hppa-linux-nat.c: Use string.h, not gdb_string.h.
* hppanbsd-tdep.c: Use string.h, not gdb_string.h.
* hppaobsd-tdep.c: Use string.h, not gdb_string.h.
* i386-cygwin-tdep.c: Use string.h, not gdb_string.h.
* i386-dicos-tdep.c: Use string.h, not gdb_string.h.
* i386-linux-nat.c: Use string.h, not gdb_string.h.
* i386-linux-tdep.c: Use string.h, not gdb_string.h.
* i386-nto-tdep.c: Use string.h, not gdb_string.h.
* i386-sol2-tdep.c: Use string.h, not gdb_string.h.
* i386-tdep.c: Use string.h, not gdb_string.h.
* i386bsd-tdep.c: Use string.h, not gdb_string.h.
* i386gnu-nat.c: Use string.h, not gdb_string.h.
* i386nbsd-tdep.c: Use string.h, not gdb_string.h.
* i386obsd-tdep.c: Use string.h, not gdb_string.h.
* i387-tdep.c: Use string.h, not gdb_string.h.
* ia64-libunwind-tdep.c: Use string.h, not gdb_string.h.
* ia64-linux-nat.c: Use string.h, not gdb_string.h.
* inf-child.c: Use string.h, not gdb_string.h.
* inf-ptrace.c: Use string.h, not gdb_string.h.
* inf-ttrace.c: Use string.h, not gdb_string.h.
* infcall.c: Use string.h, not gdb_string.h.
* infcmd.c: Use string.h, not gdb_string.h.
* inflow.c: Use string.h, not gdb_string.h.
* infrun.c: Use string.h, not gdb_string.h.
* interps.c: Use string.h, not gdb_string.h.
* iq2000-tdep.c: Use string.h, not gdb_string.h.
* irix5-nat.c: Use string.h, not gdb_string.h.
* jv-exp.y: Use string.h, not gdb_string.h.
* jv-lang.c: Use string.h, not gdb_string.h.
* jv-typeprint.c: Use string.h, not gdb_string.h.
* jv-valprint.c: Use string.h, not gdb_string.h.
* language.c: Use string.h, not gdb_string.h.
* linux-fork.c: Use string.h, not gdb_string.h.
* linux-nat.c: Use string.h, not gdb_string.h.
* lm32-tdep.c: Use string.h, not gdb_string.h.
* m2-exp.y: Use string.h, not gdb_string.h.
* m2-typeprint.c: Use string.h, not gdb_string.h.
* m32c-tdep.c: Use string.h, not gdb_string.h.
* m32r-linux-nat.c: Use string.h, not gdb_string.h.
* m32r-linux-tdep.c: Use string.h, not gdb_string.h.
* m32r-rom.c: Use string.h, not gdb_string.h.
* m32r-tdep.c: Use string.h, not gdb_string.h.
* m68hc11-tdep.c: Use string.h, not gdb_string.h.
* m68k-tdep.c: Use string.h, not gdb_string.h.
* m68kbsd-tdep.c: Use string.h, not gdb_string.h.
* m68klinux-nat.c: Use string.h, not gdb_string.h.
* m68klinux-tdep.c: Use string.h, not gdb_string.h.
* m88k-tdep.c: Use string.h, not gdb_string.h.
* macrocmd.c: Use string.h, not gdb_string.h.
* main.c: Use string.h, not gdb_string.h.
* mdebugread.c: Use string.h, not gdb_string.h.
* mem-break.c: Use string.h, not gdb_string.h.
* memattr.c: Use string.h, not gdb_string.h.
* memory-map.c: Use string.h, not gdb_string.h.
* mep-tdep.c: Use string.h, not gdb_string.h.
* mi/mi-cmd-break.c: Use string.h, not gdb_string.h.
* mi/mi-cmd-disas.c: Use string.h, not gdb_string.h.
* mi/mi-cmd-env.c: Use string.h, not gdb_string.h.
* mi/mi-cmd-stack.c: Use string.h, not gdb_string.h.
* mi/mi-cmd-var.c: Use string.h, not gdb_string.h.
* mi/mi-cmds.c: Use string.h, not gdb_string.h.
* mi/mi-console.c: Use string.h, not gdb_string.h.
* mi/mi-getopt.c: Use string.h, not gdb_string.h.
* mi/mi-interp.c: Use string.h, not gdb_string.h.
* mi/mi-main.c: Use string.h, not gdb_string.h.
* mi/mi-parse.c: Use string.h, not gdb_string.h.
* microblaze-rom.c: Use string.h, not gdb_string.h.
* microblaze-tdep.c: Use string.h, not gdb_string.h.
* mingw-hdep.c: Use string.h, not gdb_string.h.
* minidebug.c: Use string.h, not gdb_string.h.
* minsyms.c: Use string.h, not gdb_string.h.
* mips-irix-tdep.c: Use string.h, not gdb_string.h.
* mips-linux-tdep.c: Use string.h, not gdb_string.h.
* mips-tdep.c: Use string.h, not gdb_string.h.
* mips64obsd-tdep.c: Use string.h, not gdb_string.h.
* mipsnbsd-tdep.c: Use string.h, not gdb_string.h.
* mipsread.c: Use string.h, not gdb_string.h.
* mn10300-linux-tdep.c: Use string.h, not gdb_string.h.
* mn10300-tdep.c: Use string.h, not gdb_string.h.
* monitor.c: Use string.h, not gdb_string.h.
* moxie-tdep.c: Use string.h, not gdb_string.h.
* mt-tdep.c: Use string.h, not gdb_string.h.
* nbsd-tdep.c: Use string.h, not gdb_string.h.
* nios2-linux-tdep.c: Use string.h, not gdb_string.h.
* nto-procfs.c: Use string.h, not gdb_string.h.
* nto-tdep.c: Use string.h, not gdb_string.h.
* objc-lang.c: Use string.h, not gdb_string.h.
* objfiles.c: Use string.h, not gdb_string.h.
* opencl-lang.c: Use string.h, not gdb_string.h.
* osabi.c: Use string.h, not gdb_string.h.
* osdata.c: Use string.h, not gdb_string.h.
* p-exp.y: Use string.h, not gdb_string.h.
* p-lang.c: Use string.h, not gdb_string.h.
* p-typeprint.c: Use string.h, not gdb_string.h.
* parse.c: Use string.h, not gdb_string.h.
* posix-hdep.c: Use string.h, not gdb_string.h.
* ppc-linux-nat.c: Use string.h, not gdb_string.h.
* ppc-sysv-tdep.c: Use string.h, not gdb_string.h.
* ppcfbsd-tdep.c: Use string.h, not gdb_string.h.
* ppcnbsd-tdep.c: Use string.h, not gdb_string.h.
* ppcobsd-tdep.c: Use string.h, not gdb_string.h.
* printcmd.c: Use string.h, not gdb_string.h.
* procfs.c: Use string.h, not gdb_string.h.
* prologue-value.c: Use string.h, not gdb_string.h.
* python/py-auto-load.c: Use string.h, not gdb_string.h.
* python/py-gdb-readline.c: Use string.h, not gdb_string.h.
* ravenscar-thread.c: Use string.h, not gdb_string.h.
* regcache.c: Use string.h, not gdb_string.h.
* registry.c: Use string.h, not gdb_string.h.
* remote-fileio.c: Use string.h, not gdb_string.h.
* remote-m32r-sdi.c: Use string.h, not gdb_string.h.
* remote-mips.c: Use string.h, not gdb_string.h.
* remote-sim.c: Use string.h, not gdb_string.h.
* remote.c: Use string.h, not gdb_string.h.
* reverse.c: Use string.h, not gdb_string.h.
* rs6000-aix-tdep.c: Use string.h, not gdb_string.h.
* ser-base.c: Use string.h, not gdb_string.h.
* ser-go32.c: Use string.h, not gdb_string.h.
* ser-mingw.c: Use string.h, not gdb_string.h.
* ser-pipe.c: Use string.h, not gdb_string.h.
* ser-tcp.c: Use string.h, not gdb_string.h.
* ser-unix.c: Use string.h, not gdb_string.h.
* serial.c: Use string.h, not gdb_string.h.
* sh-tdep.c: Use string.h, not gdb_string.h.
* sh64-tdep.c: Use string.h, not gdb_string.h.
* shnbsd-tdep.c: Use string.h, not gdb_string.h.
* skip.c: Use string.h, not gdb_string.h.
* sol-thread.c: Use string.h, not gdb_string.h.
* solib-dsbt.c: Use string.h, not gdb_string.h.
* solib-frv.c: Use string.h, not gdb_string.h.
* solib-osf.c: Use string.h, not gdb_string.h.
* solib-spu.c: Use string.h, not gdb_string.h.
* solib-target.c: Use string.h, not gdb_string.h.
* solib.c: Use string.h, not gdb_string.h.
* somread.c: Use string.h, not gdb_string.h.
* source.c: Use string.h, not gdb_string.h.
* sparc-nat.c: Use string.h, not gdb_string.h.
* sparc-sol2-tdep.c: Use string.h, not gdb_string.h.
* sparc-tdep.c: Use string.h, not gdb_string.h.
* sparc64-tdep.c: Use string.h, not gdb_string.h.
* sparc64fbsd-tdep.c: Use string.h, not gdb_string.h.
* sparc64nbsd-tdep.c: Use string.h, not gdb_string.h.
* sparcnbsd-tdep.c: Use string.h, not gdb_string.h.
* spu-linux-nat.c: Use string.h, not gdb_string.h.
* spu-multiarch.c: Use string.h, not gdb_string.h.
* spu-tdep.c: Use string.h, not gdb_string.h.
* stabsread.c: Use string.h, not gdb_string.h.
* stack.c: Use string.h, not gdb_string.h.
* std-regs.c: Use string.h, not gdb_string.h.
* symfile.c: Use string.h, not gdb_string.h.
* symmisc.c: Use string.h, not gdb_string.h.
* symtab.c: Use string.h, not gdb_string.h.
* target.c: Use string.h, not gdb_string.h.
* thread.c: Use string.h, not gdb_string.h.
* tilegx-linux-nat.c: Use string.h, not gdb_string.h.
* tilegx-tdep.c: Use string.h, not gdb_string.h.
* top.c: Use string.h, not gdb_string.h.
* tracepoint.c: Use string.h, not gdb_string.h.
* tui/tui-command.c: Use string.h, not gdb_string.h.
* tui/tui-data.c: Use string.h, not gdb_string.h.
* tui/tui-disasm.c: Use string.h, not gdb_string.h.
* tui/tui-file.c: Use string.h, not gdb_string.h.
* tui/tui-layout.c: Use string.h, not gdb_string.h.
* tui/tui-out.c: Use string.h, not gdb_string.h.
* tui/tui-regs.c: Use string.h, not gdb_string.h.
* tui/tui-source.c: Use string.h, not gdb_string.h.
* tui/tui-stack.c: Use string.h, not gdb_string.h.
* tui/tui-win.c: Use string.h, not gdb_string.h.
* tui/tui-windata.c: Use string.h, not gdb_string.h.
* tui/tui-winsource.c: Use string.h, not gdb_string.h.
* typeprint.c: Use string.h, not gdb_string.h.
* ui-file.c: Use string.h, not gdb_string.h.
* ui-out.c: Use string.h, not gdb_string.h.
* user-regs.c: Use string.h, not gdb_string.h.
* utils.c: Use string.h, not gdb_string.h.
* v850-tdep.c: Use string.h, not gdb_string.h.
* valarith.c: Use string.h, not gdb_string.h.
* valops.c: Use string.h, not gdb_string.h.
* valprint.c: Use string.h, not gdb_string.h.
* value.c: Use string.h, not gdb_string.h.
* varobj.c: Use string.h, not gdb_string.h.
* vax-tdep.c: Use string.h, not gdb_string.h.
* vaxnbsd-tdep.c: Use string.h, not gdb_string.h.
* vaxobsd-tdep.c: Use string.h, not gdb_string.h.
* windows-nat.c: Use string.h, not gdb_string.h.
* xcoffread.c: Use string.h, not gdb_string.h.
* xml-support.c: Use string.h, not gdb_string.h.
* xstormy16-tdep.c: Use string.h, not gdb_string.h.
* xtensa-linux-nat.c: Use string.h, not gdb_string.h.
After the previous patch, there's actually no breakpoint type that
returns BPSTAT_SIGNAL_HIDE, so we can go back to having
bpstat_explains_signal return a boolean. The signal hiding actually
disappears.
gdb/
2013-11-14 Pedro Alves <palves@redhat.com>
* break-catch-sig.c (signal_catchpoint_explains_signal): Adjust to
return a boolean.
* breakpoint.c (bpstat_explains_signal): Adjust to return a
boolean.
(explains_signal_watchpoint, base_breakpoint_explains_signal):
Adjust to return a boolean.
* breakpoint.h (enum bpstat_signal_value): Delete.
(struct breakpoint_ops) <explains_signal>: New returns a boolean.
(bpstat_explains_signal): Likewise.
* infrun.c (handle_inferior_event) <random signal checks>:
bpstat_explains_signal now returns a boolean - adjust. No longer
consider hiding signals.
Looking at the current random signal checks:
if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
random_signal
= !((bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
GDB_SIGNAL_TRAP)
!= BPSTAT_SIGNAL_NO)
|| stopped_by_watchpoint
|| ecs->event_thread->control.trap_expected
|| (ecs->event_thread->control.step_range_end
&& (ecs->event_thread->control.step_resume_breakpoint
== NULL)));
else
{
enum bpstat_signal_value sval;
sval = bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
ecs->event_thread->suspend.stop_signal);
random_signal = (sval == BPSTAT_SIGNAL_NO);
if (sval == BPSTAT_SIGNAL_HIDE)
ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
}
We can observe:
- the stepping checks bit:
...
|| ecs->event_thread->control.trap_expected
|| (ecs->event_thread->control.step_range_end
&& (ecs->event_thread->control.step_resume_breakpoint
== NULL)));
...
is just like currently_stepping:
static int
currently_stepping (struct thread_info *tp)
{
return ((tp->control.step_range_end
&& tp->control.step_resume_breakpoint == NULL)
|| tp->control.trap_expected
|| bpstat_should_step ());
}
except it misses the bpstat_should_step check (***).
It's not really necessary to check bpstat_should_step in the
random signal tests, because software watchpoints always end up in
the bpstat list anyway, which means bpstat_explains_signal with
GDB_SIGNAL_TRAP always returns at least BPSSTAT_SIGNAL_HIDE, but I
think the code is clearer if we reuse currently_stepping.
*** - bpstat_should_step checks to see if there's any software
watchpoint in the breakpoint list, because we need to force the
target to single-step all the way, to evaluate the watchpoint's
value at each step.
- we never hide GDB_SIGNAL_TRAP, even if the bpstat returns
BPSTAT_SIGNAL_HIDE, which is actually the default for all
breakpoints. If we make the default be BPSTAT_SIGNAL_PASS, then
we can merge the two bpstat_explains_signal paths.
gdb/
2013-11-14 Pedro Alves <palves@redhat.com>
* breakpoint.c (bpstat_explains_signal) <Moribund locations>:
Return BPSTAT_SIGNAL_PASS instead of BPSTAT_SIGNAL_HIDE.
(explains_signal_watchpoint): Return BPSTAT_SIGNAL_PASS instead of
BPSTAT_SIGNAL_HIDE.
(base_breakpoint_explains_signal): Return BPSTAT_SIGNAL_PASS
instead of BPSTAT_SIGNAL_HIDE.
* infrun.c (handle_inferior_event): Rework random signal checks.
Pedro Alves
Patrick Palka
Gary Benson
Tom Tromey
Yao Qi
Luis Machado
Joel Brobecker
Doug Evans
Sergio Durigan Junior
Honggyu Kim
Gabriel Krisman Bertazi