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On OBS I ran into a failure in test-case gdb.threads/thread-specific-bp.exp:
...
(gdb) PASS: gdb.threads/thread-specific-bp.exp: non-stop: continue to end
info breakpoint^M
Num Type Disp Enb Address What^M
1 breakpoint keep y 0x0000555555555167 in main at $src:36^M
breakpoint already hit 1 time^M
2 breakpoint keep y 0x0000555555555151 in start at $src:23^M
breakpoint already hit 1 time^M
3 breakpoint keep y 0x0000555555555167 in main at $src:36 thread 2^M
stop only in thread 2^M
4 breakpoint keep y 0x000055555555515c in end at $src:29^M
breakpoint already hit 1 time^M
(gdb) [Thread 0x7ffff7db1640 (LWP 19984) exited]^M
Thread-specific breakpoint 3 deleted - thread 2 no longer in the thread list.^M
FAIL: gdb.threads/thread-specific-bp.exp: non-stop: \
thread-specific breakpoint was deleted (timeout)
...
Fix this by waiting for the "[Thread 0x7ffff7db1640 (LWP 19984) exited]"
message before issuing the "info breakpoint command".
Tested on x86_64-linux.
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GDB hangs when doing this:
- launch inferior with multiple threads
- multiple threads hit some breakpoint(s)
- one breakpoint hit is presented as a stop, the rest are saved as
pending wait statuses
- "set scheduler-locking on"
- resume the currently selected thread (because of scheduler-locking,
it's the only one resumed), let it execute until exit
- GDB hangs, not showing the prompt, impossible to interrupt with ^C
When the resumed thread exits, we expect the target to return a
TARGET_WAITKIND_NO_RESUMED event, and that's what we see:
[infrun] fetch_inferior_event: enter
[infrun] scoped_disable_commit_resumed: reason=handling event
[infrun] random_pending_event_thread: None found.
[Thread 0x7ffff7d9c700 (LWP 309357) exited]
[infrun] print_target_wait_results: target_wait (-1.0.0 [process -1], status) =
[infrun] print_target_wait_results: -1.0.0 [process -1],
[infrun] print_target_wait_results: status->kind = no-resumed
[infrun] handle_inferior_event: status->kind = no-resumed
[infrun] handle_no_resumed: TARGET_WAITKIND_NO_RESUMED (ignoring: found resumed)
[infrun] prepare_to_wait: prepare_to_wait
[infrun] reset: reason=handling event
[infrun] maybe_set_commit_resumed_all_targets: not requesting commit-resumed for target native, no resumed threads
[infrun] fetch_inferior_event: exit
The problem is in handle_no_resumed: we check if some other thread is
actually resumed, to see if we should ignore that event (see comments in
that function for more info). If this condition is true:
(thread->executing () || thread->has_pending_waitstatus ())
... then we ignore the event. The problem is that there are some non-resumed
threads with a pending event, which makes us ignore the event. But these
threads are not resumed, so we end up waiting while nothing executes, hence
waiting for ever.
My first fix was to change the condition to:
(thread->executing ()
|| (thread->resumed () && thread->has_pending_waitstatus ()))
... but then it occured to me that we could simply check for:
(thread->resumed ())
Since "executing" implies "resumed", checking simply for "resumed"
covers threads that are resumed and executing, as well as threads that
are resumed with a pending status, which is what we want.
Change-Id: Ie796290f8ae7f34c026ca3a8fcef7397414f4780
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PR 28065 (gdb.threads/access-mem-running-thread-exit.exp intermittent
failure) shows that GDB can hit an unexpected scenario -- it can
happen that the kernel manages to open a /proc/PID/task/LWP/mem file,
but then reading from the file returns 0/EOF, even though the process
hasn't exited or execed.
"0" out of read/write is normally what you get when the address space
of the process the file was open for is gone, because the process
execed or exited. So when GDB gets the 0, it returns memory access
failure. In the bad case in question, the process hasn't execed or
exited, so GDB fails a memory access when the access should have
worked.
GDB has code in place to gracefully handle the case of opening the
/proc/PID/task/LWP/mem just while the LWP is exiting -- most often the
open fails with EACCES or ENOENT. When it happens, GDB just tries
opening the file for a different thread of the process. The testcase
is written such that it stresses GDB's logic of closing/reopening the
/proc/PID/task/LWP/mem file, by constantly spawning short lived
threads.
However, there's a window where the kernel manages to find the thread,
but the thread exits just after and clears its address space pointer.
In this case, the kernel creates a file successfully, but the file
ends up with no address space associated, so a subsequent read/write
returns 0/EOF too, just like if the whole process had execed or
exited. This is the case in question that GDB does not handle.
Oleg Nesterov gave this suggestion as workaround for that race:
gdb can open(/proc/pid/mem) and then read (say) /proc/pid/statm.
If statm reports something non-zero, then open() was "successfull".
I think that might work. However, I didn't try it, because I realized
we have another nasty race that that wouldn't fix.
The other race I realized is that because we close/reopen the
/proc/PID/task/LWP/mem file when GDB switches to a different inferior,
then it can happen that GDB reopens /proc/PID/task/LWP/mem just after
a thread execs, and before GDB has seen the corresponding exec event.
I.e., we can open a /proc/PID/task/LWP/mem file accessing the
post-exec address space thinking we're accessing the pre-exec address
space.
A few months back, Simon, Oleg and I discussed a similar race:
[Bug gdb/26754] Race condition when resuming threads and one does an exec
https://sourceware.org/bugzilla/show_bug.cgi?id=26754
The solution back then was to make the kernel fail any ptrace
operation until the exec event is consumed, with this kernel commit:
commit dbb5afad100a828c97e012c6106566d99f041db6
Author: Oleg Nesterov <oleg@redhat.com>
AuthorDate: Wed May 12 15:33:08 2021 +0200
Commit: Linus Torvalds <torvalds@linux-foundation.org>
CommitDate: Wed May 12 10:45:22 2021 -0700
ptrace: make ptrace() fail if the tracee changed its pid unexpectedly
This however, only applies to ptrace, not to the /proc/pid/mem file
opening case. Also, even if it did apply to the file open case, we
would want to support current kernels until such a fix is more wide
spread anyhow.
So all in all, this commit gives up on the idea of only ever keeping
one /proc/pid/mem file descriptor open. Instead, make GDB open a
/proc/pid/mem per inferior, and keep it open until the inferior exits,
is detached or execs. Make GDB open the file right after the inferior
is created or is attached to or forks, at which point we know the
inferior is stable and stopped and isn't thus going to exec, or have a
thread exit, and so the file open won't fail (unless the whole process
is SIGKILLed from outside GDB, at which point it doesn't matter
whether we open the file).
This way, we avoid both races described above, at the expense of using
more file descriptors (one per inferior).
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28065
Change-Id: Iff943b95126d0f98a7973a07e989e4f020c29419
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On openSUSE Tumbleweed with glibc-debuginfo installed I get:
...
(gdb) PASS: gdb.threads/linux-dp.exp: continue to breakpoint: thread 5's print
where^M
#0 print_philosopher (n=3, left=33 '!', right=33 '!') at linux-dp.c:105^M
#1 0x0000000000401628 in philosopher (data=0x40537c) at linux-dp.c:148^M
#2 0x00007ffff7d56b37 in start_thread (arg=<optimized out>) \
at pthread_create.c:435^M
#3 0x00007ffff7ddb640 in clone3 () \
at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81^M
(gdb) PASS: gdb.threads/linux-dp.exp: first thread-specific breakpoint hit
...
while without debuginfo installed I get instead:
...
(gdb) PASS: gdb.threads/linux-dp.exp: continue to breakpoint: thread 5's print
where^M
#0 print_philosopher (n=3, left=33 '!', right=33 '!') at linux-dp.c:105^M
#1 0x0000000000401628 in philosopher (data=0x40537c) at linux-dp.c:148^M
#2 0x00007ffff7d56b37 in start_thread () from /lib64/libc.so.6^M
#3 0x00007ffff7ddb640 in clone3 () from /lib64/libc.so.6^M
(gdb) FAIL: gdb.threads/linux-dp.exp: first thread-specific breakpoint hit
...
The problem is that the regexp used:
...
"\(from .*libpthread\|at pthread_create\|in pthread_create\)"
...
expects the 'from' part to match libpthread, but in glibc 2.34 libpthread has
been merged into libc.
Fix this by updating the regexp.
Tested on x86_64-linux.
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When running test-case gdb.threads/check-libthread-db.exp on openSUSE
Tumbleweed (with glibc 2.34) I get:
...
(gdb) continue^M
Continuing.^M
[Thread debugging using libthread_db enabled]^M
Using host libthread_db library "/lib64/libthread_db.so.1".^M
Stopped due to shared library event:^M
Inferior loaded /lib64/libm.so.6^M
/lib64/libc.so.6^M
(gdb) FAIL: gdb.threads/check-libthread-db.exp: user-initiated check: continue
...
The check expect the inferior to load libpthread, but since glibc 2.34
libpthread has been integrated into glibc, and consequently it's no longer
a dependency:
...
$ ldd outputs/gdb.threads/check-libthread-db/check-libthread-db
linux-vdso.so.1 (0x00007ffe4cae4000)
libm.so.6 => /lib64/libm.so.6 (0x00007f167c77c000)
libc.so.6 => /lib64/libc.so.6 (0x00007f167c572000)
/lib64/ld-linux-x86-64.so.2 (0x00007f167c86e000)
...
Fix this by updating the regexp to expect libpthread or libc.
Tested on x86_64-linux.
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As follow-up to this discussion:
https://sourceware.org/pipermail/gdb-patches/2020-August/171385.html
... make runto_main not pass no-message to runto. This means that if we
fail to run to main, for some reason, we'll emit a FAIL. This is the
behavior we want the majority of (if not all) the time.
Without this, we rely on tests logging a failure if runto_main fails,
otherwise. They do so in a very inconsisteny mannet, sometimes using
"fail", "unsupported" or "untested". The messages also vary widly.
This patch removes all these messages as well.
Also, remove a few "fail" where we call runto (and not runto_main). by
default (without an explicit no-message argument), runto prints a
failure already. In two places, gdb.multi/multi-re-run.exp and
gdb.python/py-pp-registration.exp, remove "message" passed to runto.
This removes a few PASSes that we don't care about (but FAILs will still
be printed if we fail to run to where we want to). This aligns their
behavior with the rest of the testsuite.
Change-Id: Ib763c98c5f4fb6898886b635210d7c34bd4b9023
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gdb.threads/process-dies-while-detaching.exp
The test-case gdb.threads/process-dies-while-detaching.exp takes about 20s
when using hw watchpoints, but when forcing sw watchpoints (using the patch
mentioned in PR28375#c0), the test-case takes instead 3m14s.
Also, it show a FAIL:
...
(gdb) continue^M
Continuing.^M
Cannot find user-level thread for LWP 10324: generic error^M
(gdb) FAIL: gdb.threads/process-dies-while-detaching.exp: single-process:
continue: watchpoint: continue
...
for which PR28375 was filed.
Modify the test-case to:
- add the hw/sw axis to the watchpoint testing, to ensure that we
observe the sw watchpoint behaviour also on can-use-hw-watchpoints
architectures.
- skip the hw breakpoint testing if not supported
- set the sw watchpoint later to avoid making the test
too slow. This still triggers the same PR, but now takes just 24s.
This patch adds a KFAIL for PR28375.
Tested on x86_64-linux.
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Minimize gdb restarts, applying the following rules:
- don't use prepare_for_testing unless necessary
- don't use clean_restart unless necessary
Also, if possible, replace build_for_executable + clean_restart
with prepare_for_testing for brevity.
Touches 68 test-cases.
Tested on x86_64-linux.
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Replace {additional_flags=-fPIE ldflags=-pie} with {pie}.
This makes sure that the test-cases properly error out when using target board
unix/-fno-PIE/-no-pie.
Tested on x86_64-linux.
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When running test-case gdb.threads/continue-pending-status.exp with native, I
have:
...
(gdb) continue^M
Continuing.^M
PASS: gdb.threads/continue-pending-status.exp: attempt 0: continue for ctrl-c
^C^M
Thread 1 "continue-pendin" received signal SIGINT, Interrupt.^M
[Switching to Thread 0x7ffff7fc4740 (LWP 1276)]^M
0x00007ffff758e4c0 in __GI___nanosleep () at nanosleep.c:27^M
27 return SYSCALL_CANCEL (nanosleep, requested_time, remaining);^M
(gdb) PASS: gdb.threads/continue-pending-status.exp: attempt 0: caught interrupt
...
but with target board unix/-m32, I run into:
...
(gdb) continue^M
Continuing.^M
PASS: gdb.threads/continue-pending-status.exp: attempt 0: continue for ctrl-c
[Thread 0xf74aeb40 (LWP 31957) exited]^M
[Thread 0xf7cafb40 (LWP 31956) exited]^M
[Inferior 1 (process 31952) exited normally]^M
(gdb) Quit^M
...
The problem is that the sleep (300) call at the end of main is interrupted,
which causes the inferior to exit before the ctrl-c can be send.
This problem is described at "Interrupted System Calls" in the docs, and the
suggested solution (using a sleep loop) indeed fixes the problem.
Fix this instead using the more prevalent:
...
alarm (300);
...
while (1) sleep (1);
...
which is roughly equivalent because the sleep is called at the end of main,
but slightly better because it guards against hangs from the start rather than
from the end of main.
Likewise in gdb.base/watch_thread_num.exp.
Likewise in gdb.btrace/enable-running.exp, but use the sleep loop there,
because the sleep is not called at the end of main.
Tested on x86_64-linux.
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When running test-case gdb.threads/check-libthread-db.exp on openSUSE
Tumbleweed with glibc 2.33, I get:
...
(gdb) maint check libthread-db^M
Running libthread_db integrity checks:^M
Got thread 0x7ffff7c79b80 => 9354 => 0x7ffff7c79b80; errno = 0 ... OK^M
libthread_db integrity checks passed.^M
(gdb) FAIL: gdb.threads/check-libthread-db.exp: user-initiated check: \
libpthread.so not initialized (pattern 2)
...
The test-case expects instead:
...
Got thread 0x0 => 9354 => 0x0 ... OK^M
...
which is what I get on openSUSE Leap 15.2 with glibc 2.26, and what is
described in the test-case like this:
...
# libthread_db should fake a single thread with th_unique == NULL.
...
Using a breakpoint on check_thread_db_callback we can compare the two
scenarios, and find that in the latter case we hit this code in glibc function
iterate_thread_list in nptl_db/td_ta_thr_iter.c:
...
if (next == 0 && fake_empty)
{
/* __pthread_initialize_minimal has not run. There is just the main
thread to return. We cannot rely on its thread register. They
sometimes contain garbage that would confuse us, left by the
kernel at exec. So if it looks like initialization is incomplete,
we only fake a special descriptor for the initial thread. */
td_thrhandle_t th = { ta, 0 };
return callback (&th, cbdata_p) != 0 ? TD_DBERR : TD_OK;
}
...
while in the former case we don't because this preceding statement doesn't
result in next == 0:
...
err = DB_GET_FIELD (next, ta, head, list_t, next, 0);
...
Note that the comment mentions __pthread_initialize_minimal, but in both cases
it has already run before we hit the callback, so it's possible the comment is
no longer accurate.
The change in behaviour bisect to glibc commit 1daccf403b "nptl: Move stack
list variables into _rtld_global", which moves the initialization of stack
list variables such as __stack_user to an earlier moment, which explains well
enough the observed difference.
Fix this by updating the regexp patterns to agree with what libthread-db is
telling us.
Tested on x86_64-linux, both with glibc 2.33 and 2.26.
gdb/testsuite/ChangeLog:
2021-07-07 Tom de Vries <tdevries@suse.de>
PR testsuite/27690
* gdb.threads/check-libthread-db.exp: Update patterns for glibc 2.33.
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Currently, on GNU/Linux, if you try to access memory and you have a
running thread selected, GDB fails the memory accesses, like:
(gdb) c&
Continuing.
(gdb) p global_var
Cannot access memory at address 0x555555558010
Or:
(gdb) b main
Breakpoint 2 at 0x55555555524d: file access-mem-running.c, line 59.
Warning:
Cannot insert breakpoint 2.
Cannot access memory at address 0x55555555524d
This patch removes this limitation. It teaches the native Linux
target to read/write memory even if the target is running. And it
does this without temporarily stopping threads. We now get:
(gdb) c&
Continuing.
(gdb) p global_var
$1 = 123
(gdb) b main
Breakpoint 2 at 0x555555555259: file access-mem-running.c, line 62.
(The scenarios above work correctly with current GDBserver, because
GDBserver temporarily stops all threads in the process whenever GDB
wants to access memory (see prepare_to_access_memory /
done_accessing_memory). Freezing the whole process makes sense when
we need to be sure that we have a consistent view of memory and don't
race with the inferior changing it at the same time as GDB is
accessing it. But I think that's a too-heavy hammer for the default
behavior. I think that ideally, whether to stop all threads or not
should be policy decided by gdb core, probably best implemented by
exposing something like gdbserver's prepare_to_access_memory /
done_accessing_memory to gdb core.)
Currently, if we're accessing (reading/writing) just a few bytes, then
the Linux native backend does not try accessing memory via
/proc/<pid>/mem and goes straight to ptrace
PTRACE_PEEKTEXT/PTRACE_POKETEXT. However, ptrace always fails when
the ptracee is running. So the first step is to prefer
/proc/<pid>/mem even for small accesses. Without further changes
however, that may cause a performance regression, due to constantly
opening and closing /proc/<pid>/mem for each memory access. So the
next step is to keep the /proc/<pid>/mem file open across memory
accesses. If we have this, then it doesn't make sense anymore to even
have the ptrace fallback, so the patch disables it.
I've made it such that GDB only ever has one /proc/<pid>/mem file open
at any time. As long as a memory access hits the same inferior
process as the previous access, then we reuse the previously open
file. If however, we access memory of a different process, then we
close the previous file and open a new one for the new process.
If we wanted, we could keep one /proc/<pid>/mem file open per
inferior, and never close them (unless the inferior exits or execs).
However, having seen bfd patches recently about hitting too many open
file descriptors, I kept the logic to have only one file open tops.
Also, we need to handle memory accesses for processes for which we
don't have an inferior object, for when we need to detach a
fork-child, and we'd probaly want to handle caching the open file for
that scenario (no inferior for process) too, which would probably end
up meaning caching for last non-inferior process, which is very much
what I'm proposing anyhow. So always having one file open likely ends
up a smaller patch.
The next step is handling the case of GDB reading/writing memory
through a thread that is running and exits. The access should not
result in a user-visible failure if the inferior/process is still
alive.
Once we manage to open a /proc/<lwpid>/mem file, then that file is
usable for memory accesses even if the corresponding lwp exits and is
reaped. I double checked that trying to open the same
/proc/<lwpid>/mem path again fails because the lwp is really gone so
there's no /proc/<lwpid>/ entry on the filesystem anymore, but the
previously open file remains usable. It's only when the whole process
execs that we need to reopen a new file.
When the kernel destroys the whole address space, i.e., when the
process exits or execs, the reads/writes fail with 0 aka EOF, in which
case there's nothing else to do than returning a memory access
failure. Note this means that when we get an exec event, we need to
reopen the file, to access the process's new address space.
If we need to open (or reopen) the /proc/<pid>/mem file, and the LWP
we're opening it for exits before we open it and before we reap the
LWP (i.e., the LWP is zombie), the open fails with EACCES. The patch
handles this by just looking for another thread until it finds one
that we can open a /proc/<pid>/mem successfully for.
If we need to open (or reopen) the /proc/<pid>/mem file, and the LWP
we're opening has exited and we already reaped it, which is the case
if the selected thread is in THREAD_EXIT state, the open fails with
ENOENT. The patch handles this the same way as a zombie race
(EACCES), instead of checking upfront whether we're accessing a
known-exited thread, because that would result in more complicated
code, because we also need to handle accessing lwps that are not
listed in the core thread list, and it's the core thread list that
records the THREAD_EXIT state.
The patch includes two testcases:
#1 - gdb.base/access-mem-running.exp
This is the conceptually simplest - it is single-threaded, and has
GDB read and write memory while the program is running. It also
tests setting a breakpoint while the program is running, and checks
that the breakpoint is hit immediately.
#2 - gdb.threads/access-mem-running-thread-exit.exp
This one is more elaborate, as it continuously spawns short-lived
threads in order to exercise accessing memory just while threads are
exiting. It also spawns two different processes and alternates
accessing memory between the two processes to exercise the reopening
the /proc file frequently. This also ends up exercising GDB reading
from an exited thread frequently. I confirmed by putting abort()
calls in the EACCES/ENOENT paths added by the patch that we do hit
all of them frequently with the testcase. It also exits the
process's main thread (i.e., the main thread becomes zombie), to
make sure accessing memory in such a corner-case scenario works now
and in the future.
The tests fail on GNU/Linux native before the code changes, and pass
after. They pass against current GDBserver, again because GDBserver
supports memory access even if all threads are running, by
transparently pausing the whole process.
gdb/ChangeLog:
yyyy-mm-dd Pedro Alves <pedro@palves.net>
PR mi/15729
PR gdb/13463
* linux-nat.c (linux_nat_target::detach): Close the
/proc/<pid>/mem file if it was open for this process.
(linux_handle_extended_wait) <PTRACE_EVENT_EXEC>: Close the
/proc/<pid>/mem file if it was open for this process.
(linux_nat_target::mourn_inferior): Close the /proc/<pid>/mem file
if it was open for this process.
(linux_nat_target::xfer_partial): Adjust. Do not fall back to
inf_ptrace_target::xfer_partial for memory accesses.
(last_proc_mem_file): New.
(maybe_close_proc_mem_file): New.
(linux_proc_xfer_memory_partial_pid): New, with bits factored out
from linux_proc_xfer_partial.
(linux_proc_xfer_partial): Delete.
(linux_proc_xfer_memory_partial): New.
gdb/testsuite/ChangeLog
yyyy-mm-dd Pedro Alves <pedro@palves.net>
PR mi/15729
PR gdb/13463
* gdb.base/access-mem-running.c: New.
* gdb.base/access-mem-running.exp: New.
* gdb.threads/access-mem-running-thread-exit.c: New.
* gdb.threads/access-mem-running-thread-exit.exp: New.
Change-Id: Ib3c082528872662a3fc0ca9b31c34d4876c874c9
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With a testsuite setup modified to make expect wait a little bit longer for
gdb output (see PR27957), I reliably run into:
...
PASS: gdb.threads/multi-create-ns-info-thr.exp: continue to breakpoint 1
FAIL: gdb.threads/multi-create-ns-info-thr.exp: continue to breakpoint 2 \
(timeout)
...
This is due to this regexp:
...
-re "Breakpoint $decimal,.*$srcfile:$bp_location1" {
...
consuming several lines using the ".*" part, while it's intended to match one
line looking like this:
...
Thread 1 "multi-create-ns" hit Breakpoint 2, create_function () \
at multi-create.c:45^M
...
Fix this by limiting the regexp to one line.
Tested on x86_64-linux.
gdb/testsuite/ChangeLog:
2021-06-08 Tom de Vries <tdevries@suse.de>
* gdb.threads/multi-create-ns-info-thr.exp: Limit breakpoint regexp to
one line.
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The current test case leaves detached processes running at the end of
the test. This patch changes the test to use a barrier wait to ensure all
processes exit cleanly at the end of the tests.
gdb/testsuite/ChangeLog:
2021-06-02 Carl Love <cel@us.ibm.com>
* gdb.threads/threadapply.c: Add global mybarrier.
(main): Add pthread_barrier_init.
(thread_function): Replace while loop with myp increment and
pthread_barrier_wait.
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When running test-case gdb.threads/detach-step-over.exp with target board
readnow, I run into:
...
Reading symbols from /lib64/libc.so.6...^M
Reading symbols from \
/usr/lib/debug/lib64/libc-2.26.so-2.26-lp152.26.6.1.x86_64.debug...^M
Expanding full symbols from \
/usr/lib/debug/lib64/libc-2.26.so-2.26-lp152.26.6.1.x86_64.debug...^M
FAIL: gdb.threads/detach-step-over.exp: \
breakpoint-condition-evaluation=host: target-non-stop=on: non-stop=on: \
displaced=off: iter 2: attach (timeout)
...
Fix this by doing exp_continue when encountering the "Reading symbols" or
"Expanding full symbols" lines.
This is still fragile and times out with a higher load, similated f.i. by
stress -c 5. Fix that by using a timeout factor of 2.
Tested on x86_64-linux.
gdb/testsuite/ChangeLog:
2021-05-05 Tom de Vries <tdevries@suse.de>
* gdb.threads/detach-step-over.exp: Do exp_continue when encountering
"Reading symbols" or "Expanding full symbols" lines. Using timeout
factor of 2 for attach.
|
|
When running test-case gdb.threads/fork-plus-threads.exp with target board
readnow, I run into:
...
[LWP 9362 exited]^M
[New LWP 9365]^M
[New LWP 9363]^M
[New LWP 9364]^M
FAIL: gdb.threads/fork-plus-threads.exp: detach-on-fork=off: \
inferior 1 exited (timeout)
...
There is code in the test-case to prevent timeouts with readnow:
...
-re "Thread \[^\r\n\]+ exited" {
# Avoid timeout with check-read1
exp_continue
}
-re "New Thread \[^\r\n\]+" {
# Avoid timeout with check-read1
exp_continue
}
...
but this doesn't trigger because we get LWP rather than Thread.
Fix this by making these regexps accept LWP as well.
Tested on x86_64-linux.
gdb/testsuite/ChangeLog:
2021-05-05 Tom de Vries <tdevries@suse.de>
* gdb.threads/fork-plus-threads.exp: Handle "New LWP <n>" and
"LWP <n> exited" messages.
|
|
I noticed that using foreach_with_prefix could make things a bit
less verbose. No changes in behavior expected.
gdb/testsuite/ChangeLog:
* gdb.threads/fork-plus-threads.exp: Use foreach_with_prefix.
Change-Id: I06aa6e3d10a9cfb6ada11547aefe8c70b636ac81
|
|
When running test-case gdb.threads/gcore-thread.exp on openSUSE Tumbleweed,
I run into these XFAILs:
...
XFAIL: gdb.threads/gcore-thread.exp: clear __stack_user.next
XFAIL: gdb.threads/gcore-thread.exp: clear stack_used.next
...
Apart from the xfail, the test-case also sets core0file to "":
...
-re "No symbol \"${symbol}\" in current context\\.\r\n$gdb_prompt $" {
xfail $test
# Do not do the verification.
set core0file ""
}
...
After which we run into this FAIL, because gdb_core_cmd fails to load a
core file called "":
...
(gdb) core ^M
No core file now.^M
(gdb) FAIL: gdb.threads/gcore-thread.exp: core0file: \
re-load generated corefile
...
Fix this FAIL by skipping gdb_core_cmd if the core file is "".
Tested on x86_64-linux.
gdb/testsuite/ChangeLog:
2021-04-06 Tom de Vries <tdevries@suse.de>
PR testsuite/27691
* gdb.threads/gcore-thread.exp: Don't call gdb_core_cmd with core
file "".
|
|
Resolve all of the duplicate test names in the gdb.threads/*.exp set
of tests (that I see). Nothing very exciting here, mostly either
giving tests explicit testnames, or adding with_test_prefix.
The only interesting one is gdb.threads/execl.exp, I believe the
duplicate test name was caused by an actual duplicate test. I've
remove the simpler form of the test. I don't believe we've lost any
test coverage with this change.
gdb/testsuite/ChangeLog:
* gdb.threads/execl.exp: Remove duplicate 'info threads' test.
Make use of $gdb_test_name instead of creating a separate $test
variable.
* gdb.threads/print-threads.exp: Add a with_test_prefix instead of
adding a '($name)' at the end of each test. This also catches the
one place where '($name)' was missing, and so caused a duplicate
test name.
* gdb.threads/queue-signal.exp: Give tests unique names to avoid
duplicate test names based on the command being tested.
* gdb.threads/signal-command-multiple-signals-pending.exp:
Likewise.
* lib/gdb.exp (gdb_compile_shlib_pthreads): Tweak test name to
avoid duplicate testnames when a test script uses this proc and
also gdb_compile_pthreads.
* lib/prelink-support.exp (build_executable_own_libs): Use
with_test_prefix to avoid duplicate test names when we call
build_executable twice.
|
|
While running tests on arm-none-eabi, I noticed following errors in some
gdb.threads tests.
ERROR: can't read "testfile": no such variable
These were being caused by ${testfile} being used before 'standard_testfile'
which sets it. This patch just moves standard_testfile before the use.
2021-02-09 Abid Qadeer <abidh@codesourcery.com>
gdb/testsuite/ChangeLog:
* gdb.threads/signal-command-handle-nopass.exp: Call
'standard_testfile' before using 'testfile'.
* gdb.threads/signal-command-multiple-signals-pending.exp: Likewise.
* gdb.threads/signal-delivered-right-thread.exp: Likewise
* gdb.threads/signal-sigtrap.exp: Likewise
|
|
This adds a testcase that exercises detaching while GDB is stepping
over a breakpoint, in all combinations of:
- maint target non-stop off/on
- set non-stop on/off
- displaced stepping on/off
This exercises the bugs fixed in the previous 8 patches.
gdb/testsuite/ChangeLog:
* gdb.threads/detach-step-over.c: New file.
* gdb.threads/detach-step-over.exp: New file.
|
|
This adds a testcase exercising attaching to a multi-threaded process,
in all combinations of:
- set non-stop on/off
- maint target non-stop off/on
- "attach" vs "attach &"
This exercises the bugs fixed in the two previous patches.
gdb/testsuite/ChangeLog:
* gdb.threads/attach-non-stop.c: New file.
* gdb.threads/attach-non-stop.exp: New file.
|
|
When running test-case gdb.threads/killed-outside.exp with target board
unix/-m32, we run into:
...
(gdb) PASS: gdb.threads/killed-outside.exp: get pid of inferior
Executing on target: kill -9 10969 (timeout = 300)
spawn -ignore SIGHUP kill -9 10969^M
continue^M
Continuing.^M
[Thread 0xf7cb4b40 (LWP 10973) exited]^M
^M
Program terminated with signal SIGKILL, Killed.^M
The program no longer exists.^M
(gdb) FAIL: gdb.threads/killed-outside.exp: prompt after first continue
...
Fix this by allowing this output.
Tested on x86_64-linux.
gdb/testsuite/ChangeLog:
2021-01-26 Tom de Vries <tdevries@suse.de>
* gdb.threads/killed-outside.exp: Allow regular output.
|
|
gdb.threads/signal-while-stepping-over-bp-other-thread.exp
Commit 3ec3145c5dd6 ("gdb: introduce scoped debug prints") updated some
tests using "set debug infrun" to handle the fact that a debug print is
now shown after the prompt, after an inferior stop. The same issue
happens in gdb.threads/signal-while-stepping-over-bp-other-thread.exp.
If I run it in a loop, it eventually fails like these other tests.
The problem is that the testsuite expects to see $gdb_prompt followed by
the end of the buffer. It happens that expect reads $gdb_prompt and the
debug print at the same time, in which case the regexp never matches and
we get a timeout.
The fix is the same as was done in 3ec3145c5dd6, make the testsuite
believe that the prompt is the standard GDB prompt followed by that
debug print.
Since that test uses gdb_test_sequence, and the expected prompt is in
gdb_test_sequence, add a -prompt switch to gdb_test_sequence to override
the prompt used for that call.
gdb/testsuite/ChangeLog:
* lib/gdb.exp (gdb_test_sequence): Accept -prompt switch.
* gdb.threads/signal-while-stepping-over-bp-other-thread.exp:
Pass prompt containing debug print to gdb_test_sequence.
Change-Id: I33161c53ddab45cdfeadfd50b964f8dc3caa9729
|
|
I spent a lot of time reading infrun debug logs recently, and I think
they could be made much more readable by being indented, to clearly see
what operation is done as part of what other operation. In the current
format, there are no visual cues to tell where things start and end,
it's just a big flat list. It's also difficult to understand what
caused a given operation (e.g. a call to resume_1) to be done.
To help with this, I propose to add the new scoped_debug_start_end
structure, along with a bunch of macros to make it convenient to use.
The idea of scoped_debug_start_end is simply to print a start and end
message at construction and destruction. It also increments/decrements
a depth counter in order to make debug statements printed during this
range use some indentation. Some care is taken to handle the fact that
debug can be turned on or off in the middle of such a range. For
example, a "set debug foo 1" command in a breakpoint command, or a
superior GDB manually changing the debug_foo variable.
Two macros are added in gdbsupport/common-debug.h, which are helpers to
define module-specific macros:
- scoped_debug_start_end: takes a message that is printed both at
construction / destruction, with "start: " and "end: " prefixes.
- scoped_debug_enter_exit: prints hard-coded "enter" and "exit"
messages, to denote the entry and exit of a function.
I added some examples in the infrun module to give an idea of how it can
be used and what the result looks like. The macros are in capital
letters (INFRUN_SCOPED_DEBUG_START_END and
INFRUN_SCOPED_DEBUG_ENTER_EXIT) to mimic the existing SCOPE_EXIT, but
that can be changed if you prefer something else.
Here's an excerpt of the debug
statements printed when doing "continue", where a displaced step is
started:
[infrun] proceed: enter
[infrun] proceed: addr=0xffffffffffffffff, signal=GDB_SIGNAL_DEFAULT
[infrun] global_thread_step_over_chain_enqueue: enqueueing thread Thread 0x7ffff75a5640 (LWP 2289301) in global step over chain
[infrun] start_step_over: enter
[infrun] start_step_over: stealing global queue of threads to step, length = 1
[infrun] start_step_over: resuming [Thread 0x7ffff75a5640 (LWP 2289301)] for step-over
[infrun] resume_1: step=1, signal=GDB_SIGNAL_0, trap_expected=1, current thread [Thread 0x7ffff75a5640 (LWP 2289301)] at 0x5555555551bd
[displaced] displaced_step_prepare_throw: displaced-stepping Thread 0x7ffff75a5640 (LWP 2289301) now
[displaced] prepare: selected buffer at 0x5555555550c2
[displaced] prepare: saved 0x5555555550c2: 1e fa 31 ed 49 89 d1 5e 48 89 e2 48 83 e4 f0 50
[displaced] amd64_displaced_step_copy_insn: copy 0x5555555551bd->0x5555555550c2: c7 45 fc 00 00 00 00 eb 13 8b 05 d4 2e 00 00 83
[displaced] displaced_step_prepare_throw: prepared successfully thread=Thread 0x7ffff75a5640 (LWP 2289301), original_pc=0x5555555551bd, displaced_pc=0x5555555550c2
[displaced] resume_1: run 0x5555555550c2: c7 45 fc 00
[infrun] infrun_async: enable=1
[infrun] prepare_to_wait: prepare_to_wait
[infrun] start_step_over: [Thread 0x7ffff75a5640 (LWP 2289301)] was resumed.
[infrun] operator(): step-over queue now empty
[infrun] start_step_over: exit
[infrun] proceed: start: resuming threads, all-stop-on-top-of-non-stop
[infrun] proceed: resuming Thread 0x7ffff7da7740 (LWP 2289296)
[infrun] resume_1: step=0, signal=GDB_SIGNAL_0, trap_expected=0, current thread [Thread 0x7ffff7da7740 (LWP 2289296)] at 0x7ffff7f7d9b7
[infrun] prepare_to_wait: prepare_to_wait
[infrun] proceed: resuming Thread 0x7ffff7da6640 (LWP 2289300)
[infrun] resume_1: thread Thread 0x7ffff7da6640 (LWP 2289300) has pending wait status status->kind = stopped, signal = GDB_SIGNAL_TRAP (currently_stepping=0).
[infrun] prepare_to_wait: prepare_to_wait
[infrun] proceed: [Thread 0x7ffff75a5640 (LWP 2289301)] resumed
[infrun] proceed: resuming Thread 0x7ffff6da4640 (LWP 2289302)
[infrun] resume_1: thread Thread 0x7ffff6da4640 (LWP 2289302) has pending wait status status->kind = stopped, signal = GDB_SIGNAL_TRAP (currently_stepping=0).
[infrun] prepare_to_wait: prepare_to_wait
[infrun] proceed: end: resuming threads, all-stop-on-top-of-non-stop
[infrun] proceed: exit
We can easily see where the call to `proceed` starts and end. We can
also see why there are a bunch of resume_1 calls, it's because we are
resuming threads, emulating all-stop on top of a non-stop target.
We also see that debug statements nest well with other modules that have
been migrated to use the "new" debug statement helpers (because they all
use debug_prefixed_vprintf in the end. I think this is desirable, for
example we could see the debug statements about reading the DWARF info
of a library nested under the debug statements about loading that
library.
Of course, modules that haven't been migrated to use the "new" helpers
will still print without indentations. This will be one good reason to
migrate them.
I think the runtime cost (when debug statements are disabled) of this is
reasonable, given the improvement in readability. There is the cost of
the conditionals (like standard debug statements), one more condition
(if (m_must_decrement_print_depth)) and the cost of constructing a stack
object, which means copying a fews pointers.
Adding the print in fetch_inferior_event breaks some tests that use "set
debug infrun", because it prints a debug statement after the prompt. I
adapted these tests to cope with it, by using the "-prompt" switch of
gdb_test_multiple to as if this debug statement is part of the expected
prompt. It's unfortunate that we have to do this, but I think the debug
print is useful, and I don't want a few tests to get in the way of
adding good debug output.
gdbsupport/ChangeLog:
* common-debug.h (debug_print_depth): New.
(struct scoped_debug_start_end): New.
(scoped_debug_start_end): New.
(scoped_debug_enter_exit): New.
* common-debug.cc (debug_prefixed_vprintf): Print indentation.
gdb/ChangeLog:
* debug.c (debug_print_depth): New.
* infrun.h (INFRUN_SCOPED_DEBUG_START_END): New.
(INFRUN_SCOPED_DEBUG_ENTER_EXIT): New.
* infrun.c (start_step_over): Use
INFRUN_SCOPED_DEBUG_ENTER_EXIT.
(proceed): Use INFRUN_SCOPED_DEBUG_ENTER_EXIT and
INFRUN_SCOPED_DEBUG_START_END.
(fetch_inferior_event): Use INFRUN_SCOPED_DEBUG_ENTER_EXIT.
gdbserver/ChangeLog:
* debug.cc (debug_print_depth): New.
gdb/testsuite/ChangeLog:
* gdb.base/ui-redirect.exp: Expect infrun debug print after
prompt.
* gdb.threads/ia64-sigill.exp: Likewise.
* gdb.threads/watchthreads-reorder.exp: Likewise.
Change-Id: I7c3805e6487807aa63a1bae318876a0c69dce949
|
|
This commits the result of running gdb/copyright.py as per our Start
of New Year procedure...
gdb/ChangeLog
Update copyright year range in copyright header of all GDB files.
|
|
displaced steps
Today, GDB only allows a single displaced stepping operation to happen
per inferior at a time. There is a single displaced stepping buffer per
inferior, whose address is fixed (obtained with
gdbarch_displaced_step_location), managed by infrun.c.
In the case of the AMD ROCm target [1] (in the context of which this
work has been done), it is typical to have thousands of threads (or
waves, in SMT terminology) executing the same code, hitting the same
breakpoint (possibly conditional) and needing to to displaced step it at
the same time. The limitation of only one displaced step executing at a
any given time becomes a real bottleneck.
To fix this bottleneck, we want to make it possible for threads of a
same inferior to execute multiple displaced steps in parallel. This
patch builds the foundation for that.
In essence, this patch moves the task of preparing a displaced step and
cleaning up after to gdbarch functions. This allows using different
schemes for allocating and managing displaced stepping buffers for
different platforms. The gdbarch decides how to assign a buffer to a
thread that needs to execute a displaced step.
On the ROCm target, we are able to allocate one displaced stepping
buffer per thread, so a thread will never have to wait to execute a
displaced step.
On Linux, the entry point of the executable if used as the displaced
stepping buffer, since we assume that this code won't get used after
startup. From what I saw (I checked with a binary generated against
glibc and musl), on AMD64 we have enough space there to fit two
displaced stepping buffers. A subsequent patch makes AMD64/Linux use
two buffers.
In addition to having multiple displaced stepping buffers, there is also
the idea of sharing displaced stepping buffers between threads. Two
threads doing displaced steps for the same PC could use the same buffer
at the same time. Two threads stepping over the same instruction (same
opcode) at two different PCs may also be able to share a displaced
stepping buffer. This is an idea for future patches, but the
architecture built by this patch is made to allow this.
Now, the implementation details. The main part of this patch is moving
the responsibility of preparing and finishing a displaced step to the
gdbarch. Before this patch, preparing a displaced step is driven by the
displaced_step_prepare_throw function. It does some calls to the
gdbarch to do some low-level operations, but the high-level logic is
there. The steps are roughly:
- Ask the gdbarch for the displaced step buffer location
- Save the existing bytes in the displaced step buffer
- Ask the gdbarch to copy the instruction into the displaced step buffer
- Set the pc of the thread to the beginning of the displaced step buffer
Similarly, the "fixup" phase, executed after the instruction was
successfully single-stepped, is driven by the infrun code (function
displaced_step_finish). The steps are roughly:
- Restore the original bytes in the displaced stepping buffer
- Ask the gdbarch to fixup the instruction result (adjust the target's
registers or memory to do as if the instruction had been executed in
its original location)
The displaced_step_inferior_state::step_thread field indicates which
thread (if any) is currently using the displaced stepping buffer, so it
is used by displaced_step_prepare_throw to check if the displaced
stepping buffer is free to use or not.
This patch defers the whole task of preparing and cleaning up after a
displaced step to the gdbarch. Two new main gdbarch methods are added,
with the following semantics:
- gdbarch_displaced_step_prepare: Prepare for the given thread to
execute a displaced step of the instruction located at its current PC.
Upon return, everything should be ready for GDB to resume the thread
(with either a single step or continue, as indicated by
gdbarch_displaced_step_hw_singlestep) to make it displaced step the
instruction.
- gdbarch_displaced_step_finish: Called when the thread stopped after
having started a displaced step. Verify if the instruction was
executed, if so apply any fixup required to compensate for the fact
that the instruction was executed at a different place than its
original pc. Release any resources that were allocated for this
displaced step. Upon return, everything should be ready for GDB to
resume the thread in its "normal" code path.
The displaced_step_prepare_throw function now pretty much just offloads
to gdbarch_displaced_step_prepare and the displaced_step_finish function
offloads to gdbarch_displaced_step_finish.
The gdbarch_displaced_step_location method is now unnecessary, so is
removed. Indeed, the core of GDB doesn't know how many displaced step
buffers there are nor where they are.
To keep the existing behavior for existing architectures, the logic that
was previously implemented in infrun.c for preparing and finishing a
displaced step is moved to displaced-stepping.c, to the
displaced_step_buffer class. Architectures are modified to implement
the new gdbarch methods using this class. The behavior is not expected
to change.
The other important change (which arises from the above) is that the
core of GDB no longer prevents concurrent displaced steps. Before this
patch, start_step_over walks the global step over chain and tries to
initiate a step over (whether it is in-line or displaced). It follows
these rules:
- if an in-line step is in progress (in any inferior), don't start any
other step over
- if a displaced step is in progress for an inferior, don't start
another displaced step for that inferior
After starting a displaced step for a given inferior, it won't start
another displaced step for that inferior.
In the new code, start_step_over simply tries to initiate step overs for
all the threads in the list. But because threads may be added back to
the global list as it iterates the global list, trying to initiate step
overs, start_step_over now starts by stealing the global queue into a
local queue and iterates on the local queue. In the typical case, each
thread will either:
- have initiated a displaced step and be resumed
- have been added back by the global step over queue by
displaced_step_prepare_throw, because the gdbarch will have returned
that there aren't enough resources (i.e. buffers) to initiate a
displaced step for that thread
Lastly, if start_step_over initiates an in-line step, it stops
iterating, and moves back whatever remaining threads it had in its local
step over queue to the global step over queue.
Two other gdbarch methods are added, to handle some slightly annoying
corner cases. They feel awkwardly specific to these cases, but I don't
see any way around them:
- gdbarch_displaced_step_copy_insn_closure_by_addr: in
arm_pc_is_thumb, arm-tdep.c wants to get the closure for a given
buffer address.
- gdbarch_displaced_step_restore_all_in_ptid: when a process forks
(at least on Linux), the address space is copied. If some displaced
step buffers were in use at the time of the fork, we need to restore
the original bytes in the child's address space.
These two adjustments are also made in infrun.c:
- prepare_for_detach: there may be multiple threads doing displaced
steps when we detach, so wait until all of them are done
- handle_inferior_event: when we handle a fork event for a given
thread, it's possible that other threads are doing a displaced step at
the same time. Make sure to restore the displaced step buffer
contents in the child for them.
[1] https://github.com/ROCm-Developer-Tools/ROCgdb
gdb/ChangeLog:
* displaced-stepping.h (struct
displaced_step_copy_insn_closure): Adjust comments.
(struct displaced_step_inferior_state) <step_thread,
step_gdbarch, step_closure, step_original, step_copy,
step_saved_copy>: Remove fields.
(struct displaced_step_thread_state): New.
(struct displaced_step_buffer): New.
* displaced-stepping.c (displaced_step_buffer::prepare): New.
(write_memory_ptid): Move from infrun.c.
(displaced_step_instruction_executed_successfully): New,
factored out of displaced_step_finish.
(displaced_step_buffer::finish): New.
(displaced_step_buffer::copy_insn_closure_by_addr): New.
(displaced_step_buffer::restore_in_ptid): New.
* gdbarch.sh (displaced_step_location): Remove.
(displaced_step_prepare, displaced_step_finish,
displaced_step_copy_insn_closure_by_addr,
displaced_step_restore_all_in_ptid): New.
* gdbarch.c: Re-generate.
* gdbarch.h: Re-generate.
* gdbthread.h (class thread_info) <displaced_step_state>: New
field.
(thread_step_over_chain_remove): New declaration.
(thread_step_over_chain_next): New declaration.
(thread_step_over_chain_length): New declaration.
* thread.c (thread_step_over_chain_remove): Make non-static.
(thread_step_over_chain_next): New.
(global_thread_step_over_chain_next): Use
thread_step_over_chain_next.
(thread_step_over_chain_length): New.
(global_thread_step_over_chain_enqueue): Add debug print.
(global_thread_step_over_chain_remove): Add debug print.
* infrun.h (get_displaced_step_copy_insn_closure_by_addr):
Remove.
* infrun.c (get_displaced_stepping_state): New.
(displaced_step_in_progress_any_inferior): Remove.
(displaced_step_in_progress_thread): Adjust.
(displaced_step_in_progress): Adjust.
(displaced_step_in_progress_any_thread): New.
(get_displaced_step_copy_insn_closure_by_addr): Remove.
(gdbarch_supports_displaced_stepping): Use
gdbarch_displaced_step_prepare_p.
(displaced_step_reset): Change parameter from inferior to
thread.
(displaced_step_prepare_throw): Implement using
gdbarch_displaced_step_prepare.
(write_memory_ptid): Move to displaced-step.c.
(displaced_step_restore): Remove.
(displaced_step_finish): Implement using
gdbarch_displaced_step_finish.
(start_step_over): Allow starting more than one displaced step.
(prepare_for_detach): Handle possibly multiple threads doing
displaced steps.
(handle_inferior_event): Handle possibility that fork event
happens while another thread displaced steps.
* linux-tdep.h (linux_displaced_step_prepare): New.
(linux_displaced_step_finish): New.
(linux_displaced_step_copy_insn_closure_by_addr): New.
(linux_displaced_step_restore_all_in_ptid): New.
(linux_init_abi): Add supports_displaced_step parameter.
* linux-tdep.c (struct linux_info) <disp_step_buf>: New field.
(linux_displaced_step_prepare): New.
(linux_displaced_step_finish): New.
(linux_displaced_step_copy_insn_closure_by_addr): New.
(linux_displaced_step_restore_all_in_ptid): New.
(linux_init_abi): Add supports_displaced_step parameter,
register displaced step methods if true.
(_initialize_linux_tdep): Register inferior_execd observer.
* amd64-linux-tdep.c (amd64_linux_init_abi_common): Add
supports_displaced_step parameter, adjust call to
linux_init_abi. Remove call to
set_gdbarch_displaced_step_location.
(amd64_linux_init_abi): Adjust call to
amd64_linux_init_abi_common.
(amd64_x32_linux_init_abi): Likewise.
* aarch64-linux-tdep.c (aarch64_linux_init_abi): Adjust call to
linux_init_abi. Remove call to
set_gdbarch_displaced_step_location.
* arm-linux-tdep.c (arm_linux_init_abi): Likewise.
* i386-linux-tdep.c (i386_linux_init_abi): Likewise.
* alpha-linux-tdep.c (alpha_linux_init_abi): Adjust call to
linux_init_abi.
* arc-linux-tdep.c (arc_linux_init_osabi): Likewise.
* bfin-linux-tdep.c (bfin_linux_init_abi): Likewise.
* cris-linux-tdep.c (cris_linux_init_abi): Likewise.
* csky-linux-tdep.c (csky_linux_init_abi): Likewise.
* frv-linux-tdep.c (frv_linux_init_abi): Likewise.
* hppa-linux-tdep.c (hppa_linux_init_abi): Likewise.
* ia64-linux-tdep.c (ia64_linux_init_abi): Likewise.
* m32r-linux-tdep.c (m32r_linux_init_abi): Likewise.
* m68k-linux-tdep.c (m68k_linux_init_abi): Likewise.
* microblaze-linux-tdep.c (microblaze_linux_init_abi): Likewise.
* mips-linux-tdep.c (mips_linux_init_abi): Likewise.
* mn10300-linux-tdep.c (am33_linux_init_osabi): Likewise.
* nios2-linux-tdep.c (nios2_linux_init_abi): Likewise.
* or1k-linux-tdep.c (or1k_linux_init_abi): Likewise.
* riscv-linux-tdep.c (riscv_linux_init_abi): Likewise.
* s390-linux-tdep.c (s390_linux_init_abi_any): Likewise.
* sh-linux-tdep.c (sh_linux_init_abi): Likewise.
* sparc-linux-tdep.c (sparc32_linux_init_abi): Likewise.
* sparc64-linux-tdep.c (sparc64_linux_init_abi): Likewise.
* tic6x-linux-tdep.c (tic6x_uclinux_init_abi): Likewise.
* tilegx-linux-tdep.c (tilegx_linux_init_abi): Likewise.
* xtensa-linux-tdep.c (xtensa_linux_init_abi): Likewise.
* ppc-linux-tdep.c (ppc_linux_init_abi): Adjust call to
linux_init_abi. Remove call to
set_gdbarch_displaced_step_location.
* arm-tdep.c (arm_pc_is_thumb): Call
gdbarch_displaced_step_copy_insn_closure_by_addr instead of
get_displaced_step_copy_insn_closure_by_addr.
* rs6000-aix-tdep.c (rs6000_aix_init_osabi): Adjust calls to
clear gdbarch methods.
* rs6000-tdep.c (struct ppc_inferior_data): New structure.
(get_ppc_per_inferior): New function.
(ppc_displaced_step_prepare): New function.
(ppc_displaced_step_finish): New function.
(ppc_displaced_step_restore_all_in_ptid): New function.
(rs6000_gdbarch_init): Register new gdbarch methods.
* s390-tdep.c (s390_gdbarch_init): Don't call
set_gdbarch_displaced_step_location, set new gdbarch methods.
gdb/testsuite/ChangeLog:
* gdb.arch/amd64-disp-step-avx.exp: Adjust pattern.
* gdb.threads/forking-threads-plus-breakpoint.exp: Likewise.
* gdb.threads/non-stop-fair-events.exp: Likewise.
Change-Id: I387cd235a442d0620ec43608fd3dc0097fcbf8c8
|
|
When a process does an exec, all its program space is replaced with the
newly loaded executable. All non-main threads disappear and the main
thread starts executing at the entry point of the new executable.
Things can go wrong if a displaced step operation is in progress while
we process the exec event.
If the main thread is the one executing the displaced step: when that
thread (now executing in the new executable) stops somewhere (say, at a
breakpoint), displaced_step_fixup will run and clear up the state. We
will execute the "fixup" phase for the instruction we single-stepped in
the old program space. We are now in a completely different context,
so doing the fixup may corrupt the state.
If it is a non-main thread that is doing the displaced step: while
handling the exec event, GDB deletes the thread_info representing that
thread (since the thread doesn't exist in the inferior after the exec).
But inferior::displaced_step_state::step_thread will still point to it.
When handling events later, this condition, in displaced_step_fixup,
will likely never be true:
/* Was this event for the thread we displaced? */
if (displaced->step_thread != event_thread)
return 0;
... since displaced->step_thread points to a deleted thread (unless that
storage gets re-used for a new thread_info, but that wouldn't be good
either). This effectively makes the displaced stepping buffer occupied
for ever. When a thread in the new program space will want to do a
displaced step, it will wait for ever.
I think we simply need to reset the displaced stepping state of the
inferior on exec. Everything execution-related that existed before the
exec is now gone.
Similarly, if a thread does an in-line step over an exec syscall
instruction, nothing clears the in-line step over info when the event is
handled. So it the in-line step over info stays there indefinitely, and
things hang because we can never start another step over. To fix this,
I added a call to clear_step_over_info in infrun_inferior_execd.
Add a test with a program with two threads that does an exec. The test
includes the following axes:
- whether it's the leader thread or the other thread that does the exec.
- whether the exec'r and exec'd program have different text segment
addresses. This is to hopefully catch cases where the displaced
stepping info doesn't get reset, and GDB later tries to restore bytes
of the old address space in the new address space. If the mapped
addresses are different, we should get some memory error. This
happens without the patch applied:
$ ./gdb -q -nx --data-directory=data-directory testsuite/outputs/gdb.threads/step-over-exec/step-over-exec-execr-thread-leader-diff-text-segs-true -ex "b main" -ex r -ex "b my_execve_syscall if 0" -ex "set displaced-stepping on"
...
Breakpoint 1, main (argc=1, argv=0x7fffffffde38) at /home/simark/src/binutils-gdb/gdb/testsuite/gdb.threads/step-over-exec.c:69
69 argv0 = argv[0];
Breakpoint 2 at 0x60133a: file /home/simark/src/binutils-gdb/gdb/testsuite/lib/my-syscalls.S, line 34.
(gdb) c
Continuing.
[New Thread 0x7ffff7c62640 (LWP 1455423)]
Leader going in exec.
Exec-ing /home/simark/build/binutils-gdb/gdb/testsuite/outputs/gdb.threads/step-over-exec/step-over-exec-execr-thread-leader-diff-text-segs-true-execd
[Thread 0x7ffff7c62640 (LWP 1455423) exited]
process 1455418 is executing new program: /home/simark/build/binutils-gdb/gdb/testsuite/outputs/gdb.threads/step-over-exec/step-over-exec-execr-thread-leader-diff-text-segs-true-execd
Error in re-setting breakpoint 2: Function "my_execve_syscall" not defined.
No unwaited-for children left.
(gdb) n
Single stepping until exit from function _start,
which has no line number information.
Cannot access memory at address 0x6010d2
(gdb)
- Whether displaced stepping is allowed or not, so that we end up
testing both displaced stepping and in-line stepping on arches that do
support displaced stepping (otherwise, it just tests in-line stepping
twice I suppose)
To be able to precisely put a breakpoint on the syscall instruction, I
added a small assembly file (lib/my-syscalls.S) that contains minimal
Linux syscall wrappers. I prefer that to the strategy used in
gdb.base/step-over-syscall.exp, which is to stepi into the glibc wrapper
until we find something that looks like a syscall instruction, I find
that more predictable.
gdb/ChangeLog:
* infrun.c (infrun_inferior_execd): New function.
(_initialize_infrun): Attach inferior_execd observer.
gdb/testsuite/ChangeLog:
* gdb.threads/step-over-exec.exp: New.
* gdb.threads/step-over-exec.c: New.
* gdb.threads/step-over-exec-execd.c: New.
* lib/my-syscalls.S: New.
* lib/my-syscalls.h: New.
Change-Id: I1bbc8538e683f53af5b980091849086f4fec5ff9
|
|
gdb/testsuite/ChangeLog:
* gdb.threads/non-ldr-exc-1.exp: Fix indentation.
Change-Id: I02ba8a518aae9cb67106d09bef92968a7078e91e
|
|
Replace the manual with_test_prefix in the do_test proc with using
foreach_with_prefix at the top-level. This helps reduce the indentation
level of the code a bit, and makes the test names in sync with the
variable names used in the code.
gdb/testsuite/ChangeLog:
* gdb.threads/non-ldr-exc-1.exp: Use foreach_with_prefix.
(do_test): Don't use with_test_prefix.
* gdb.threads/non-ldr-exc-2.exp: Use foreach_with_prefix.
(do_test): Don't use with_test_prefix.
* gdb.threads/non-ldr-exc-3.exp: Use foreach_with_prefix.
(do_test): Don't use with_test_prefix.
* gdb.threads/non-ldr-exc-4.exp: Use foreach_with_prefix.
(do_test): Don't use with_test_prefix.
Change-Id: I3af1df2eee1a8add427a67b6048bb6dede41cbeb
|
|
Maybe there's something I don't understand in that test, but the comment
seems wrong. It checks what happens when the non-leader thread does an
exit, not the leader.
gdb/testsuite/ChangeLog:
* gdb.threads/non-ldr-exit.exp: Fix comment.
Change-Id: I35c96a70c097fa9529737874f54f3f78036008a4
|
|
Clang fails to compile gdb.threads/tls-so_extern_main.c, giving the
following error:
/gdbtest/src/gdb/testsuite/gdb.threads/tls-so_extern_main.c:28:1:
warning: non-void function does not return a value [-Wreturn-type]
This commit adds a return statement to the offending function.
gdb/testsuite/ChangeLog:
* gdb.threads/tls-so_extern_main.c (tls_ptr): Add missing return
statement.
|
|
With test-case gdb.threads/tls.exp, we get these:
...
DUPLICATE: gdb.threads/tls.exp: selected thread: 4
DUPLICATE: gdb.threads/tls.exp: selected thread: 2
DUPLICATE: gdb.threads/tls.exp: selected thread: 3
...
Fix these using with_test_prefix.
Tested on x86_64-linux.
gdb/testsuite/ChangeLog:
2020-10-29 Tom de Vries <tdevries@suse.de>
* gdb.threads/tls.exp: Fix DUPLICATEs.
|
|
This commit does 's/runto main/runto_main/g' throughout.
gdb/testsuite/ChangeLog:
* gdb.ada/fun_in_declare.exp: Use "runto_main" instead of
"runto main".
* gdb.ada/small_reg_param.exp: Likewise.
* gdb.arch/powerpc-d128-regs.exp: Likewise.
* gdb.base/annota1.exp: Likewise.
* gdb.base/anon.exp: Likewise.
* gdb.base/breakpoint-in-ro-region.exp: Likewise.
* gdb.base/dprintf-non-stop.exp: Likewise.
* gdb.base/dprintf.exp: Likewise.
* gdb.base/gdb11530.exp: Likewise.
* gdb.base/gdb11531.exp: Likewise.
* gdb.base/gnu_vector.exp: Likewise.
* gdb.base/interrupt-noterm.exp: Likewise.
* gdb.base/memattr.exp: Likewise.
* gdb.base/step-over-syscall.exp: Likewise.
* gdb.base/watch-cond-infcall.exp: Likewise.
* gdb.base/watch-read.exp: Likewise.
* gdb.base/watch-vfork.exp: Likewise.
* gdb.base/watch_thread_num.exp: Likewise.
* gdb.base/watchpoint-stops-at-right-insn.exp: Likewise.
* gdb.guile/scm-frame-inline.exp: Likewise.
* gdb.linespec/explicit.exp: Likewise.
* gdb.opt/inline-break.exp: Likewise.
* gdb.python/py-frame-inline.exp: Likewise.
* gdb.reverse/break-precsave.exp: Likewise.
* gdb.reverse/break-reverse.exp: Likewise.
* gdb.reverse/consecutive-precsave.exp: Likewise.
* gdb.reverse/consecutive-reverse.exp: Likewise.
* gdb.reverse/finish-precsave.exp: Likewise.
* gdb.reverse/finish-reverse.exp: Likewise.
* gdb.reverse/fstatat-reverse.exp: Likewise.
* gdb.reverse/getresuid-reverse.exp: Likewise.
* gdb.reverse/i386-precsave.exp: Likewise.
* gdb.reverse/i386-reverse.exp: Likewise.
* gdb.reverse/i386-sse-reverse.exp: Likewise.
* gdb.reverse/i387-env-reverse.exp: Likewise.
* gdb.reverse/i387-stack-reverse.exp: Likewise.
* gdb.reverse/insn-reverse.exp: Likewise.
* gdb.reverse/machinestate-precsave.exp: Likewise.
* gdb.reverse/machinestate.exp: Likewise.
* gdb.reverse/pipe-reverse.exp: Likewise.
* gdb.reverse/readv-reverse.exp: Likewise.
* gdb.reverse/recvmsg-reverse.exp: Likewise.
* gdb.reverse/rerun-prec.exp: Likewise.
* gdb.reverse/s390-mvcle.exp: Likewise.
* gdb.reverse/solib-precsave.exp: Likewise.
* gdb.reverse/solib-reverse.exp: Likewise.
* gdb.reverse/step-precsave.exp: Likewise.
* gdb.reverse/step-reverse.exp: Likewise.
* gdb.reverse/time-reverse.exp: Likewise.
* gdb.reverse/until-precsave.exp: Likewise.
* gdb.reverse/until-reverse.exp: Likewise.
* gdb.reverse/waitpid-reverse.exp: Likewise.
* gdb.reverse/watch-precsave.exp: Likewise.
* gdb.reverse/watch-reverse.exp: Likewise.
* gdb.threads/kill.exp: Likewise.
* gdb.threads/tid-reuse.exp: Likewise.
Change-Id: I70f457253836019880b4d7fb981936afa56724c2
|
|
Commit 1eb8556f5a8b ("gdb: add infrun_debug_printf macro") changed the
debug output format for `set debug infrun 1`. The test
gdb.threads/stepi-random-signal.exp uses that debug output, and was
updated, but not correctly. It results in this failure:
FAIL: gdb.threads/stepi-random-signal.exp: stepi (no random signal)
Fix it by adjusting the pattern in the test.
gdb/testsuite/ChangeLog:
PR gdb/26532
* gdb.threads/stepi-random-signal.exp: Update pattern.
Change-Id: If5fa525e9545e32a286effe6a6184358374bd37c
|
|
Introduce this macro to print debug statements in the infrun.c file,
same idea as what was done in 9327494e0eeb ("gdb: add
linux_nat_debug_printf macro").
Although in this case, there are places outside infrun.c that print
debug statements if debug_infrun is set. So the macro has to be
declared in the header file, so that it can be used in these other
files.
Note one special case. In stop_all_threads, I've used an explicit
if (debug_infrun)
infrun_debug_printf_1 ("stop_all_threads", "done");
for the message in the SCOPE_EXIT. Otherwise, the message appears like
this:
[infrun] operator(): done
Until we find a better solution for extracting a meaningful function
name for lambda functions, I think it's fine to handle these special
cases manually, they are quite rare.
Some tests need to be updated, because they rely on some infrun debug
statements.
gdb/ChangeLog:
* infrun.h (infrun_debug_printf_1): New function declaration.
(infrun_debug_printf): New macro.
* infrun.c (infrun_debug_printf_1): Use infrun_debug_printf
throughout.
(infrun_debug_printf): New function.
* breakpoint.c (should_be_inserted): Use infrun_debug_printf.
(handle_jit_event): Likewise.
gdb/testsuite/ChangeLog:
* gdb.base/gdb-sigterm.exp (do_test): Update expected regexp.
* gdb.threads/signal-while-stepping-over-bp-other-thread.exp:
Likewise.
* gdb.threads/stepi-random-signal.exp: Likewise.
Change-Id: I66433c8a9caa64c8525ab57c593022b9d1956d5c
|
|
In openmp test-case gdb.threads/omp-par-scope.exp we xfail and kfail dependent
on omp_get_thread_num (). Since execution order of the threads can vary from
execution to execution, this can cause changes in test results.
F.i., we can see this difference between two test runs:
...
-KFAIL: single_scope: first thread: print i3 (PRMS: gdb/22214)
+PASS: single_scope: first thread: print i3
-PASS: single_scope: second thread: print i3
+KFAIL: single_scope: second thread: print i3 (PRMS: gdb/22214)
...
In both cases, the KFAIL is for omp_get_thread_num () == 1, but in one case
that corresponds to the first thread executing that bit of code, and in the
other case to the second thread.
Get rid of this difference by stabilizing execution order.
Tested on x86_64-linux.
gdb/testsuite/ChangeLog:
2020-07-20 Tom de Vries <tdevries@suse.de>
* gdb.threads/omp-par-scope.c (lock, lock2): New variable.
(omp_set_lock_in_order): New function.
(single_scope, multi_scope, nested_func, nested_parallel): Use
omp_set_lock_in_order and omp_unset_lock.
(main): Init and destroy lock and lock2.
|
|
gdb.threads/attach-slow-waitpid.exp
When building gdb using CFLAGS/CXXFLAGS+=-fsanitizer=address and
LDFLAGS+=-lasan, and running test-case gdb.threads/attach-slow-waitpid.exp,
we get:
...
spawn gdb -nw -nx -data-directory data-directory^M
==16079==ASan runtime does not come first in initial library list; \
you should either link runtime to your application or manually preload \
it with LD_PRELOAD.^M
ERROR: (eof) GDB never initialized.
ERROR: : spawn id exp10 not open
while executing
"expect {
-i exp10 -timeout 120
-re "Kill the program being debugged. .y or n. $" {
send_gdb "y\n" answer
verbose "\t\tKilling previous pro..."
("uplevel" body line 1)
invoked from within
"uplevel $body" NONE : spawn id exp10 not open
WARNING: remote_expect statement without a default case
ERROR: : spawn id exp10 not open
while executing
"expect {
-i exp10 -timeout 120
-re "Reading symbols from.*LZMA support was disabled.*$gdb_prompt $" {
verbose "\t\tLoaded $arg into $GDB; .gnu_..."
("uplevel" body line 1)
invoked from within
"uplevel $body" NONE : spawn id exp10 not open
ERROR: Couldn't load attach-slow-waitpid into GDB (eof).
ERROR: Couldn't send attach 16070 to GDB.
UNRESOLVED: gdb.threads/attach-slow-waitpid.exp: attach to target
...
Bail out at the first ERROR, such that we have instead:
...
ERROR: (eof) GDB never initialized.
UNTESTED: gdb.threads/attach-slow-waitpid.exp: \
Couldn't start GDB with preloaded lib
...
Tested on x86_64-linux.
gdb/testsuite/ChangeLog:
2020-07-20 Tom de Vries <tdevries@suse.de>
* gdb.threads/attach-slow-waitpid.exp: Bail out if gdb_start fails.
|
|
Starting glibc 2.30, unistd.h declares gettid (for _GNU_SOURCE).
This clashes with a static gettid in test source
clone-new-thread-event.c:
...
gdb compile failed, gdb.threads/clone-new-thread-event.c:46:1: error: \
static declaration of 'gettid' follows non-static declaration
46 | gettid (void)
| ^~~~~~
In file included from /usr/include/unistd.h:1170,
from gdb.threads/clone-new-thread-event.c:27:
/usr/include/bits/unistd_ext.h:34:16: note: previous declaration of 'gettid' \
was here
34 | extern __pid_t gettid (void) __THROW;
| ^~~~~~
...
Fix this by renaming the static gettid to local_gettid.
Tested on x86_64-linux.
gdb/testsuite/ChangeLog:
2020-07-14 Tom de Vries <tdevries@suse.de>
* gdb.threads/clone-new-thread-event.c (gettid): Rename to ...
(local_gettid): ... this.
(fn): Update.
|
|
When running the testsuite with clang, a number of testcases fail to
build with the following errors:
warning: control reaches end of non-void function [-Wreturn-type]
warning: control may reach end of non-void function [-Wreturn-type]
This prevents a number of testcases from executing. This commit fixes.
gdb/testsuite/ChangeLog:
* gdb.base/info-os.c (main): Add return statement.
* gdb.base/info_minsym.c (minsym_fun): Likewise.
* gdb.base/large-frame-2.c (func): Likewise.
* gdb.base/pr10179-a.c (foo1, bar1): Likewise.
* gdb.base/pr10179-b.c (foo2): Likewise.
* gdb.base/valgrind-disp-step.c (foo): Likewise.
* gdb.base/watch-cond.c (func): Likewise.
* gdb.multi/goodbye.c (verylongfun): Likewise.
* gdb.multi/hello.c (commonfun): Likewise.
* gdb.python/py-finish-breakpoint.c (call_longjmp): Likewise.
* gdb.threads/fork-plus-threads.c (thread_func): Likewise.
* gdb.threads/forking-threads-plus-breakpoint.c (thread_forks):
Likewise.
* gdb.threads/hand-call-new-thread.c (foo): Likewise.
* gdb.threads/interrupt-while-step-over.c (child_function):
Likewise.
* gdb.trace/actions-changed.c (end): Likewise.
|
|
gdb/stubs/ChangeLog:
2020-04-28 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>
* ia64vms-stub.c: Fix typo in comment (thead -> thread).
gdb/testsuite/ChangeLog:
2020-04-28 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>
* gdb.threads/stop-with-handle.exp: Fix typo in comment
(theads -> threads).
gdbsupport/ChangeLog:
2020-04-28 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>
* gdb-sigmask.h: Fix typo (pthead_sigmask -> pthread_sigmask).
|
|
Consider a test-case consisting of source file test.c:
...
extern int aaa;
int
main (void)
{
return 0;
}
...
and test-2.c:
...
int aaa = 33;
...
compiled with debug info only for test.c:
...
$ gcc -c test.c -g; gcc -c test2.c; gcc test.o test2.o -g
...
When trying to print aaa, we get:
...
$ gdb -batch a.out -ex "print aaa"
'aaa' has unknown type; cast it to its declared type
...
but with -readnow we have:
...
$ gdb -readnow -batch a.out -ex "print aaa"
$1 = 33
...
In the -readnow case, the symbol for aaa in the full symtab has
LOC_UNRESOLVED, and the symbol type is combined with the minimal symbol
address, to read the value and print it without cast.
Without the -readnow, we create partial symbols, but the aaa decl is missing
from the partial symtabs, so we find it only in the minimal symbols, resulting
in the cast request. If the aaa decl would have been in the partial symtabs,
it would have been found, and the full symtab would have been expanded, after
which things would be as with -readnow.
The function add_partial_symbol has a comment on the LOC_UNRESOLVED +
minimal symbol addres construct at DW_TAG_variable handling:
...
else if (pdi->is_external)
{
/* Global Variable.
Don't enter into the minimal symbol tables as there is
a minimal symbol table entry from the ELF symbols already.
Enter into partial symbol table if it has a location
descriptor or a type.
If the location descriptor is missing, new_symbol will create
a LOC_UNRESOLVED symbol, the address of the variable will then
be determined from the minimal symbol table whenever the variable
is referenced.
...
but it's not triggered due to this test in scan_partial_symbols:
...
case DW_TAG_variable:
...
if (!pdi->is_declaration)
{
add_partial_symbol (pdi, cu);
}
...
Fix this in scan_partial_symbols by allowing external variable decls to be
added to the partial symtabs.
Build and reg-tested on x86_64-linux.
The patch caused this regression:
...
(gdb) print a_thread_local^M
Cannot find thread-local storage for process 0, executable file tls/tls:^M
Cannot find thread-local variables on this target^M
(gdb) FAIL: gdb.threads/tls.exp: print a_thread_local
...
while without the patch we have:
...
(gdb) print a_thread_local^M
Cannot read `a_thread_local' without registers^M
(gdb) PASS: gdb.threads/tls.exp: print a_thread_local
...
However, without the patch but with -readnow we have the same FAIL as with the
patch (filed as PR25807). In other words, the patch has the effect that we
get the same result with and without -readnow.
This can be explained as follows. Without the patch, and without -readnow, we
have two a_thread_locals, the def and the decl:
...
$ gdb -batch outputs/gdb.threads/tls/tls \
-ex "maint expand-symtabs" \
-ex "print a_thread_local" \
-ex "maint print symbols" \
| grep "a_thread_local;"
Cannot read `a_thread_local' without registers
int a_thread_local; computed at runtime
int a_thread_local; unresolved
...
while without the patch and with -readnow, we have the opposite order:
...
$ gdb -readnow -batch outputs/gdb.threads/tls/tls \
-ex "maint expand-symtabs" \
-ex "print a_thread_local" \
-ex "maint print symbols" \
| grep "a_thread_local;"
Cannot find thread-local storage for process 0, executable file tls/tls:
Cannot find thread-local variables on this target
int a_thread_local; unresolved
int a_thread_local; computed at runtime
...
With the patch we have the same order with and without -readnow, but just a
different one than before without -readnow.
Mark the "Cannot find thread-local variables on this target" variant a PR25807
kfail.
gdb/ChangeLog:
2020-04-22 Tom de Vries <tdevries@suse.de>
PR symtab/25764
* dwarf2/read.c (scan_partial_symbols): Allow external variable decls
in psymtabs.
gdb/testsuite/ChangeLog:
2020-04-22 Tom de Vries <tdevries@suse.de>
PR symtab/25764
* gdb.base/psym-external-decl-2.c: New test.
* gdb.base/psym-external-decl.c: New test.
* gdb.base/psym-external-decl.exp: New file.
* gdb.threads/tls.exp: Add PR25807 kfail.
|
|
Consider the test-case from this patch, compiled with pthread support:
...
$ gcc gdb/testsuite/gdb.threads/killed-outside.c -lpthread -g
...
After running to all_started, we can print pid:
...
$ gdb a.out -ex "b all_started" -ex run -ex "delete 1" -ex "p pid"
...
Reading symbols from a.out...
Breakpoint 1 at 0x40072b: file killed-outside.c, line 29.
Starting program: /data/gdb_versions/devel/a.out
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
[New Thread 0x7ffff77fc700 (LWP 3155)]
Thread 1 "a.out" hit Breakpoint 1, all_started () at killed-outside.c:29
29 }
$1 = 3151
(gdb)
...
If we then kill the inferior using an external SIGKILL:
...
(gdb) shell kill -9 3151
...
and subsequently continue:
...
(gdb) c
Continuing.
Couldn't get registers: No such process.
Couldn't get registers: No such process.
(gdb) Couldn't get registers: No such process.
(gdb) Couldn't get registers: No such process.
(gdb) Couldn't get registers: No such process.
<repeat>
...
gdb hangs repeating the same warning. Typing control-C no longer helps,
and we have to kill gdb.
This is a regression since commit 873657b9e8 "Preserve selected thread in
all-stop w/ background execution". The commit adds a
scoped_restore_current_thread typed variable restore_thread to
fetch_inferior_event, and the hang is caused by the constructor throwing an
exception.
Fix this by catching the exception in the constructor.
Build and reg-tested on x86_64-linux.
gdb/ChangeLog:
2020-04-21 Tom de Vries <tdevries@suse.de>
PR gdb/25471
* thread.c
(scoped_restore_current_thread::scoped_restore_current_thread): Catch
exception in get_frame_id.
gdb/testsuite/ChangeLog:
2020-04-21 Tom de Vries <tdevries@suse.de>
PR gdb/25471
* gdb.threads/killed-outside.c: New test.
* gdb.threads/killed-outside.exp: New file.
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|
When running test-case gdb.threads/omp-par-scope.exp, I get this XPASS:
...
XPASS: gdb.threads/omp-par-scope.exp: nested_parallel: outer_threads: \
outer stop: get valueof "num"
...
for test:
...
set thread_num [get_valueof "" "num" "unknown"]
...
The intention of the test is to get the value of local variable num, which
has been set to:
...
int num = omp_get_thread_num ();
...
but the actually printed value is 'num':
...
(gdb) print num^M
$76 = num^M
...
This is due to the fact that num is missing in the locals, so instead we find
the enum member 'num' of enum expression_operator in glibc/intl/plural-exp.h.
Fix this by getting the value using a new proc get_local_valueof, which uses
the "info locals" commands to get the value.
Tested on x86_64-linux, with gcc 7.5.0 (where the test xfails) and gcc
10.0.1 (where the test passes).
|
|
When running test-cases gdb.threads/step-over-lands-on-breakpoint.exp and
gdb.threads/step-over-trips-on-watchpoint.exp with target board
unix/-flto/-O0/-flto-partition=none/-ffat-lto-objects, we run into timeouts
due not being able to set a breakpoint and then trying to continue to that
breakpoint.
In total, we run into 186 timeouts, which roughly corresponds to half an hour:
...
$ grep "FAIL.*(timeout)" gdb.sum \
| awk '{print $2}' \
| sort \
| uniq -c
66 gdb.threads/step-over-lands-on-breakpoint.exp:
120 gdb.threads/step-over-trips-on-watchpoint.exp:
...
Fix this by bailing out if the first break fails.
Tested on x86_64-linux, both with native and with target board mentioned above.
gdb/testsuite/ChangeLog:
2020-03-20 Tom de Vries <tdevries@suse.de>
* gdb.threads/step-over-lands-on-breakpoint.exp (do_test): Bail out if
first break fails.
* gdb.threads/step-over-trips-on-watchpoint.exp: (do_test): Same.
|
|
When running test-case gdb.threads/attach-many-short-lived-threads.exp with
check-read1, I ran into:
...
FAIL: gdb.threads/attach-many-short-lived-threads.exp: iter 1: \
no new threads (timeout)
...
Fix this by rewriting the gdb_test_multiple call using -lbl and exp_continue.
Tested on x86_64-linux, with make targets check and check-read1.
gdb/testsuite/ChangeLog:
2020-03-14 Tom de Vries <tdevries@suse.de>
* gdb.threads/attach-many-short-lived-threads.exp: Read "info threads"
result in line-by-line fashion.
|
|
When running the gdb.threads/execl.exp test-case, we run into this FAIL:
...
(gdb) continue^M
Continuing.^M
^M
Thread 1 "execl" hit Breakpoint 2, __GI_execl (path=0x6024a0 \
"build/gdb/testsuite/outputs/gdb.threads/execl/execl1", \
arg=<optimized out>) at execl.c:51^M
51 if (execl (new_image, new_image, NULL) == -1) \
/* set breakpoint here */^M
(gdb) FAIL: gdb.threads/execl.exp: continue across exec
...
The fail is due to the continue command hitting a breakpoint in __GI_execl
rather than main.
This problem originates from where we execute the "b 51" command, and get two
breakpoint locations:
...
(gdb) run ^M
Starting program: build/gdb/testsuite/outputs/gdb.threads/execl/execl ^M
[Thread debugging using libthread_db enabled]^M
Using host libthread_db library "/lib64/libthread_db.so.1".^M
^M
Breakpoint 1, main (argc=1, argv=0x7fffffffd3f8) at gdb.threads/execl.c:44^M
44 pthread_create (&thread1, NULL, thread_function, NULL);^M
(gdb) b 51^M
Breakpoint 2 at 0x400787: gdb.threads/execl.c:51. (2 locations)^M
(gdb) PASS: gdb.threads/execl.exp: set breakpoint at execl
...
Adding a "info breakpoints" command, we can see the locations:
...
(gdb) info breakpoints^M
Num Type Disp Enb Address What^M
1 breakpoint keep y 0x00000000004006ee in main at \
gdb.threads/execl.c:44^M
breakpoint already hit 1 time^M
2 breakpoint keep y <MULTIPLE> ^M
2.1 y 0x0000000000400787 in main at \
gdb.threads/execl.c:51^M
2.2 y 0x00007ffff758d925 in __GI_execl at \
execl.c:51^M
(gdb) PASS: gdb.threads/execl.exp: info breakpoints
...
The fact that the __GI_execl breakpoint location is there, is a bug, filed as
PR25656. Without debug info for GLIBC though, the bug is not triggered.
Fix the FAIL by working around the bug, and deleting the breakpoint after
hitting the first breakpoint location.
Tested on x86_64-linux.
gdb/testsuite/ChangeLog:
2020-03-12 Tom de Vries <tdevries@suse.de>
* gdb.threads/execl.exp: Delete breakpoint after hitting it.
|
|
I ran into:
...
Thread 3.1 "watchpoint-fork" hit Breakpoint 3, marker () at \
watchpoint-fork-mt.c:42^M
42 }^M
(gdb) parent2: 1945^M
FAIL: gdb.threads/watchpoint-fork.exp: child: multithreaded: breakpoint (A) \
after the second fork (timeout)
...
The problem is that the FAILing gdb_test expects '(gdb) ' to be the last thing
printed, but the inferior prints something after that.
A similar FAIL is described in the sources in watchpoint-fork-parent.c:
...
printf ("child%d: %d\n", nr, (int) getpid ());
/* Delay to get both the "child%d" and "parent%d" message printed
without a race breaking expect by its endless wait on `$gdb_prompt$':
Breakpoint 3, marker () at watchpoint-fork.c:33
33 }
(gdb) parent2: 14223 */
i = sleep (1);
...
I noticed that while the executables print output, the output is not verified in
the test-case, so it's merely debug output.
Fix this by:
- guarding the prints in the executables (as well as related
sleep and setbuf calls) with #if DEBUG, and
- compiling by default with DEBUG=0.
gdb/testsuite/ChangeLog:
2020-01-29 Tom de Vries <tdevries@suse.de>
* gdb.threads/watchpoint-fork-child.c: Guard prints with #if DEBUG.
* gdb.threads/watchpoint-fork-mt.c: Same.
* gdb.threads/watchpoint-fork-parent.c: Same.
* gdb.threads/watchpoint-fork-st.c: Same.
* gdb.threads/watchpoint-fork.exp: Compile with DEBUG=0.
Change-Id: I63efd4c7771f96b5f5cd87ef2ab36795484ae2be
|
|
This commit extends the CLI a bit for multi-target, in three ways.
#1 - New "info connections" command.
This is a new command that lists the open connections (process_stratum
targets). For example, if you're debugging two remote connections, a
couple local/native processes, and a core dump, all at the same time,
you might see something like this:
(gdb) info connections
Num What Description
1 remote 192.168.0.1:9999 Remote serial target in gdb-specific protocol
2 remote 192.168.0.2:9998 Remote serial target in gdb-specific protocol
* 3 native Native process
4 core Local core dump file
#2 - New "info inferiors" "Connection" column
You'll also see a new matching "Connection" column in "info
inferiors", showing you which connection an inferior is bound to:
(gdb) info inferiors
Num Description Connection Executable
1 process 18526 1 (remote 192.168.0.1:9999) target:/tmp/a.out
2 process 18531 2 (remote 192.168.0.2:9998) target:/tmp/a.out
3 process 19115 3 (native) /tmp/prog1
4 process 6286 4 (core) myprogram
* 5 process 19122 3 (native) /bin/hello
#3 - Makes "add-inferior" show the inferior's target connection
"add-inferior" now shows you the connection you've just bound the
inferior to, which is the current process_stratum target:
(gdb) add-inferior
[New inferior 2]
Added inferior 2 on connection 1 (extended-remote localhost:2346)
gdb/ChangeLog:
2020-01-10 Pedro Alves <palves@redhat.com>
* Makefile.in (COMMON_SFILES): Add target-connection.c.
* inferior.c (uiout_field_connection): New function.
(print_inferior): Add new "connection-id" column.
(add_inferior_command): Show connection number/string of added
inferior.
* process-stratum-target.h
(process_stratum_target::connection_string): New virtual method.
(process_stratum_target::connection_number): New field.
* remote.c (remote_target::connection_string): New override.
* target-connection.c: New file.
* target-connection.h: New file.
* target.c (decref_target): Remove process_stratum targets from
the connection list.
(target_stack::push): Add process_stratum targets to the
connection list.
gdb/testsuite/ChangeLog:
2020-01-10 Pedro Alves <palves@redhat.com>
* gdb.base/kill-detach-inferiors-cmd.exp: Adjust expected output
of "add-inferior".
* gdb.base/quit-live.exp: Likewise.
* gdb.base/remote-exec-file.exp: Likewise.
* gdb.guile/scm-progspace.exp: Likewise.
* gdb.linespec/linespec.exp: Likewise.
* gdb.mi/new-ui-mi-sync.exp: Likewise.
* gdb.mi/user-selected-context-sync.exp: Likewise.
* gdb.multi/multi-target.exp (setup): Add "info connection" and
"info inferiors" tests.
* gdb.multi/remove-inferiors.exp: Adjust expected output of
"add-inferior".
* gdb.multi/watchpoint-multi.exp: Likewise.
* gdb.python/py-inferior.exp: Likewise.
* gdb.server/extended-remote-restart.exp: Likewise.
* gdb.threads/fork-plus-threads.exp: Adjust expected output of
"info inferiors".
* gdb.threads/forking-threads-plus-breakpoint.exp: Likewise.
* gdb.trace/report.exp: Likewise.
|
|
In non-stop mode, if you resume the program in the background (with
"continue&", for example), then gdb makes sure to not switch the
current thread behind your back. That means that you can be sure that
the commands you type apply to the thread you selected, even if some
other thread that was running in the background hits some event just
while you're typing.
In all-stop mode, however, if you resume the program in the
background, gdb let's the current thread switch behind your back.
This is bogus, of course. All-stop and non-stop background
resumptions should behave the same.
This patch fixes that, and adds a testcase that exposes the bad
behavior in current master.
The fork-running-state.exp changes are necessary because that
preexisting testcase was expecting the old behavior:
Before:
continue &
Continuing.
(gdb)
[Attaching after process 8199 fork to child process 8203]
[New inferior 2 (process 8203)]
info threads
Id Target Id Frame
1.1 process 8199 "fork-running-st" (running)
* 2.1 process 8203 "fork-running-st" (running)
(gdb)
After:
continue &
Continuing.
(gdb)
[Attaching after process 24660 fork to child process 24664]
[New inferior 2 (process 24664)]
info threads
Id Target Id Frame
* 1.1 process 24660 "fork-running-st" (running)
2.1 process 24664 "fork-running-st" (running)
(gdb)
Here we see that before this patch GDB switches current inferior to
the new inferior behind the user's back, as a side effect of handling
the fork.
The delete_exited_threads call in inferior_appeared is there to fix an
issue that Baris found in a previous version of this patch. The
fetch_inferior_event change increases the refcount of the current
thread, and in case the fetched inferior event denotes a thread exit,
the thread will not be deleted right away. A non-deleted but exited
thread stays in the inferior's thread list. This, in turn, causes the
"init_thread_list" call in inferior.c to be skipped. A consequence is
that the global thread ID counter is not restarted if the current
thread exits, and then the inferior is restarted:
(gdb) start
Temporary breakpoint 1 at 0x4004d6: file main.c, line 21.
Starting program: /tmp/main
Temporary breakpoint 1, main () at main.c:21
21 foo ();
(gdb) info threads -gid
Id GId Target Id Frame
* 1 1 process 16106 "main" main () at main.c:21
(gdb) c
Continuing.
[Inferior 1 (process 16106) exited normally]
(gdb) start
Temporary breakpoint 2 at 0x4004d6: file main.c, line 21.
Starting program: /tmp/main
Temporary breakpoint 2, main () at main.c:21
21 foo ();
(gdb) info threads -gid
Id GId Target Id Frame
* 1 2 process 16138 "main" main () at main.c:21
^^^
Notice that GId == 2 above. It should have been "1" instead.
The new tids-git-reset.exp testcase exercises the problem above.
gdb/ChangeLog:
2020-01-10 Pedro Alves <palves@redhat.com>
* gdbthread.h (scoped_restore_current_thread)
<dont_restore, restore, m_dont_restore>: Declare.
* thread.c (thread_alive): Add assertion. Return bool.
(switch_to_thread_if_alive): New.
(prune_threads): Switch inferior/thread.
(print_thread_info_1): Switch thread before calling target methods.
(scoped_restore_current_thread::restore): New, factored out from
...
(scoped_restore_current_thread::~scoped_restore_current_thread):
... this.
(scoped_restore_current_thread::scoped_restore_current_thread):
Add assertion.
(thread_apply_all_command, thread_select): Use
switch_to_thread_if_alive.
gdb/testsuite/ChangeLog:
2020-01-10 Pedro Alves <palves@redhat.com>
* gdb.base/fork-running-state.exp (do_test): Adjust expected
output.
* gdb.threads/async.c: New.
* gdb.threads/async.exp: New.
* gdb.multi/tids-gid-reset.c: New.
* gdb.multi/tids-gid-reset.exp: New.
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