Commit Graph

17 Commits

Author SHA1 Message Date
Maxim Levitsky
b9a0de3773 scripts/gdb: implement 'qemu bt'
This script first runs the regular gdb's 'bt' command, and then if we are in a
coroutine it prints the coroutines backtraces in the order in which they
were called.

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20201217155436.927320-3-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-01-12 12:38:03 +01:00
Maxim Levitsky
4cbf8efc5b scripts/gdb: fix 'qemu coroutine' when users selects a non topmost stack frame
The code that dumps the stack frame works like that:
* save current registers
* overwrite current registers (including rip/rsp) with coroutine snapshot
  in the jmpbuf
* print backtrace
* restore the saved registers.

If the user has currently selected a non topmost stack frame in gdb,
the above code will still restore the selected frame registers,
but the gdb will then lose the selected frame index, which makes it impossible
to switch back to frame 0, to continue debugging the executable.

Therefore switch temporarily to the topmost frame of the stack
for the above code.

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20201217155436.927320-2-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-01-12 12:38:03 +01:00
Philippe Mathieu-Daudé
6acc5c0469 scripts/qemugdb: Remove shebang header
These scripts are loaded as plugin by GDB (and they don't
have any __main__ entry point). Remove the shebang header.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Acked-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200512103238.7078-2-philmd@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2020-05-31 13:56:46 +02:00
Alex Bennée
390947ed2a scripts/qemugdb: re-license timers.py to GPLv2 or later
I'm the sole author (aside from a one line by Greg fixing encoding)
and I was asked nicely on IRC to bring it into line with the rest of
the files.

Cc: Greg Kurz <groug@kaod.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>
2019-03-12 08:04:22 +01:00
Paolo Bonzini
328eb60dc1 qemugdb: fix licensing
qemu-gdb.py was committed after 2012-01-13, so the notice about
GPL v2-only contributions does not apply.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-03-11 16:55:52 +01:00
Vladimir Sementsov-Ogievskiy
6eaa20c836 qemugdb/coroutine: fix arch_prctl has unknown return type
qemu coroutine command results in following error output:

Python Exception <class 'gdb.error'> 'arch_prctl' has unknown return
type; cast the call to its declared return type: Error occurred in
Python command: 'arch_prctl' has unknown return type; cast the call to
its declared return type

Fix it by giving it what it wants: arch_prctl return type.

Information on the topic:
   https://sourceware.org/gdb/onlinedocs/gdb/Calling.html

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20190206151425.105871-1-vsementsov@virtuozzo.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-02-12 11:49:17 +08:00
Greg Kurz
b90d80a73e scripts/qemu-gdb/timers.py: define encoding in header comment
This is required otherwise python complains because of the
accentuated letter in Alex's last name:

Traceback (most recent call last):
  File "scripts/qemu-gdb.py", line 29, in <module>
    from qemugdb import aio, mtree, coroutine, tcg, timers
  File "scripts/qemugdb/timers.py", line 1
SyntaxError: Non-ASCII character '\xc3' in file scripts/qemugdb/timers.py
 on line 1, but no encoding declared;
 see http://www.python.org/peps/pep-0263.html for details

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <151629549711.18276.15497684562308683805.stgit@bahia.lan>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-02-05 13:54:39 +01:00
Alex Bennée
c24999fa53 scripts/qemu-gdb/timers.py: new helper to dump timer state
This introduces the qemu-gdb command "qemu timers" which will dump the
state of the main timers in the system.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-01-16 14:54:51 +01:00
Alex Bennée
f1cd52d891 scripts/qemu-gdb: add simple tcg lock status helper
Add a simple helper to dump lock state.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-01-16 14:54:51 +01:00
Alex Bennée
8037fa55ac scripts/qemugdb/mtree.py: fix up mtree dump
Since QEMU has been able to build with native Int128 support this was
broken as it attempts to fish values out of the non-existent
structure. Also the alias print was trying to make a %x out of
gdb.ValueType directly which didn't seem to work.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
2017-04-07 15:24:56 +01:00
Yang Wei
d6b6913276 scripts/gdb: Fix a python exception in mtree.py
The following exception is threw:
Python Exception <class 'NameError'> name 'long' is not defined:
Error occurred in Python command: name 'long' is not defined

Python 2.4+, int()/long() have been unified, so replace long
with int.

Signed-off-by: Yang Wei <w90p710@gmail.com>
Message-id: 1449316340-4030-1-git-send-email-w90p710@gmail.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2015-12-22 16:01:08 +08:00
Dr. David Alan Gilbert
c900ef86c5 gdb command: qemu handlers
A new gdb commands are added:

  qemu handlers

     That dumps an AioContext list (by default qemu_aio_context)
     possibly including a backtrace for cases it knows about
     (with the verbose option).  Intended to help find why something
     is hanging waiting for IO.

  Use 'qemu handlers --verbose iohandler_ctx'  to find out why
your incoming migration is stuck.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-id: 1445951385-11924-1-git-send-email-dgilbert@redhat.com

V2:
  Merge into one command with optional handlers arg, and only do
    backtrace in verbose mode

 (gdb) qemu handlers
 ----
 {pfd = {fd = 6, events = 25, revents = 0}, io_read = 0x55869656ffd0
 <event_notifier_dummy_cb>, io_write = 0x0, deleted = 0, opaque =
 0x558698c4ce08, node = {le_next = 0x0, le_prev = 0x558698c4cdc0}}

 (gdb) qemu handlers iohandler_ctx
 ----
 {pfd = {fd = 9, events = 25, revents = 0}, io_read = 0x558696581380
 <fd_coroutine_enter>, io_write = 0x0, deleted = 0, opaque =
 0x558698dc99d0, node = {le_next = 0x558698c4cca0, le_prev =
 0x558698c4c1d0}}
 ----
 {pfd = {fd = 4, events = 25, revents = 0}, io_read = 0x55869657b330
 <sigfd_handler>, io_write = 0x0, deleted = 0, opaque = 0x4, node =
 {le_next = 0x558698c4c260, le_prev = 0x558699f72508}}
 ----
 {pfd = {fd = 5, events = 25, revents = 0}, io_read = 0x55869656ffd0
 <event_notifier_dummy_cb>, io_write = 0x0, deleted = 0, opaque =
 0x558698c4c218, node = {le_next = 0x0, le_prev = 0x558698c4ccc8}}
 ----
 (gdb) qemu handlers --verbose iohandler_ctx
 ----
 {pfd = {fd = 9, events = 25, revents = 0}, io_read = 0x558696581380
 <fd_coroutine_enter>, io_write = 0x0, deleted = 0, opaque =
 0x558698dc99d0, node = {le_next = 0x558698c4cca0, le_prev =
 0x558698c4c1d0}}
 #0  0x0000558696581820 in qemu_coroutine_switch
 (from_=from_@entry=0x558698cb3cf0, to_=to_@entry=0x7f421c37eac8,
 action=action@entry=COROUTINE_YIELD) at
 /home/dgilbert/git/qemu/coroutine-ucontext.c:177
 #1  0x0000558696580c00 in qemu_coroutine_yield () at
 /home/dgilbert/git/qemu/qemu-coroutine.c:145
 #2  0x00005586965814f5 in yield_until_fd_readable (fd=9) at
 /home/dgilbert/git/qemu/qemu-coroutine-io.c:90
 #3  0x0000558696523937 in socket_get_buffer (opaque=0x55869a3dc620,
 buf=0x558698c505a0 "", pos=<optimized out>, size=32768) at
 /home/dgilbert/git/qemu/migration/qemu-file-unix.c:101
 #4  0x0000558696521fac in qemu_fill_buffer (f=0x558698c50570) at
 /home/dgilbert/git/qemu/migration/qemu-file.c:227
 #5  0x0000558696522989 in qemu_peek_byte (f=0x558698c50570, offset=0)
     at /home/dgilbert/git/qemu/migration/qemu-file.c:507
 #6  0x0000558696522bf4 in qemu_get_be32 (f=0x558698c50570) at
 /home/dgilbert/git/qemu/migration/qemu-file.c:520
 #7  0x0000558696522bf4 in qemu_get_be32 (f=f@entry=0x558698c50570)
     at /home/dgilbert/git/qemu/migration/qemu-file.c:604
 #8  0x0000558696347e5c in qemu_loadvm_state (f=f@entry=0x558698c50570)
     at /home/dgilbert/git/qemu/migration/savevm.c:1821
 #9  0x000055869651de8c in process_incoming_migration_co
 (opaque=0x558698c50570)
     at /home/dgilbert/git/qemu/migration/migration.c:336
 #10 0x000055869658188a in coroutine_trampoline (i0=<optimized out>,
 i1=<optimized out>)
     at /home/dgilbert/git/qemu/coroutine-ucontext.c:80
 #11 0x00007f420f05df10 in __start_context () at /lib64/libc.so.6
 #12 0x00007ffc40815f50 in  ()
 #13 0x0000000000000000 in  ()

  ----
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2015-10-29 17:59:27 +00:00
Paolo Bonzini
a201b0ff28 qemu-gdb: add $qemu_coroutine_sp and $qemu_coroutine_pc
These can be useful to manually get a stack trace of a coroutine inside
a core dump.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1444636974-19950-4-git-send-email-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2015-10-29 17:59:26 +00:00
Paolo Bonzini
80ab31b257 qemu-gdb: extract parts of "qemu coroutine" implementation
Provide useful Python functions to reach and decipher a jmpbuf.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1444636974-19950-3-git-send-email-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2015-10-29 17:59:26 +00:00
Paolo Bonzini
1138f24645 qemu-gdb: allow using glibc_pointer_guard() on core dumps
get_fs_base() cannot be run on a core dump, because it uses the arch_prctl
system call.  The fs base is the value that is returned by pthread_self(),
and it would be nice to just glean it from the "info threads" output:

* 1    Thread 0x7f16a3fff700 (LWP 33642) pthread_cond_wait@@GLIBC_2.3.2 ()
              ^^^^^^^^^^^^^^

but unfortunately the gdb API does not provide that.  Instead, we can
look for the "arg" argument of the start_thread function if glibc debug
information are available.  If not, fall back to the old mechanism.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1444636974-19950-2-git-send-email-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2015-10-29 17:59:26 +00:00
Peter Maydell
191590f09d scripts/qemu-gdb: Split CoroutineCommand into its own file
Split the implementation of CoroutineCommand into its own file.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 1439574392-4403-3-git-send-email-peter.maydell@linaro.org
2015-09-11 17:14:49 +01:00
Peter Maydell
93b1b365dc scripts/qemu-gdb: Split MtreeCommand into its own module
As we add more commands to our Python gdb debugging support, it's
going to get unwieldy to have everything in a single file. Split
the implementation of the 'mtree' command from qemu-gdb.py into
its own module.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 1439574392-4403-2-git-send-email-peter.maydell@linaro.org
2015-09-11 17:14:49 +01:00