Dumping coroutines don't yet work with coredumps. Let's make it work.
We still kept most of the old code because they can be either more
flexible, or prettier. Only add the fallbacks when they stop working.
Currently the raw unwind is pretty ugly, but it works, like this:
(gdb) qemu bt
#0 process_incoming_migration_co (opaque=0x0) at ../migration/migration.c:788
#1 0x000055ae6c0dc4d9 in coroutine_trampoline (i0=-1711718576, i1=21934) at ../util/coroutine-ucontext.c:175
#2 0x00007f9f59d72f40 in ??? () at /lib64/libc.so.6
#3 0x00007ffd549214a0 in ??? ()
#4 0x0000000000000000 in ??? ()
Coroutine at 0x7f9f4c57c748:
#0 0x55ae6c0dc9a8 in qemu_coroutine_switch<+120> () at ../util/coroutine-ucontext.c:321
#1 0x55ae6c0da2f8 in qemu_aio_coroutine_enter<+356> () at ../util/qemu-coroutine.c:293
#2 0x55ae6c0da3f1 in qemu_coroutine_enter<+34> () at ../util/qemu-coroutine.c:316
#3 0x55ae6baf775e in migration_incoming_process<+43> () at ../migration/migration.c:876
#4 0x55ae6baf7ab4 in migration_ioc_process_incoming<+490> () at ../migration/migration.c:1008
#5 0x55ae6bae9ae7 in migration_channel_process_incoming<+145> () at ../migration/channel.c:45
#6 0x55ae6bb18e35 in socket_accept_incoming_migration<+118> () at ../migration/socket.c:132
#7 0x55ae6be939ef in qio_net_listener_channel_func<+131> () at ../io/net-listener.c:54
#8 0x55ae6be8ce1a in qio_channel_fd_source_dispatch<+78> () at ../io/channel-watch.c:84
#9 0x7f9f5b26728c in g_main_context_dispatch_unlocked.lto_priv<+315> ()
#10 0x7f9f5b267555 in g_main_context_dispatch<+36> ()
#11 0x55ae6c0d91a7 in glib_pollfds_poll<+90> () at ../util/main-loop.c:287
#12 0x55ae6c0d9235 in os_host_main_loop_wait<+128> () at ../util/main-loop.c:310
#13 0x55ae6c0d9364 in main_loop_wait<+203> () at ../util/main-loop.c:589
#14 0x55ae6bac212a in qemu_main_loop<+41> () at ../system/runstate.c:835
#15 0x55ae6bfdf522 in qemu_default_main<+19> () at ../system/main.c:37
#16 0x55ae6bfdf55f in main<+40> () at ../system/main.c:48
#17 0x7f9f59d42248 in __libc_start_call_main<+119> ()
#18 0x7f9f59d4230b in __libc_start_main_impl<+138> ()
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-ID: <20241212204801.1420528-4-peterx@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
There're a bunch of code trying to fetch fs_base in different ways. IIUC
the simplest way instead is "$fs_base". It also has the benefit that it'll
work for both live gdb session or coredumps.
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-ID: <20241212204801.1420528-3-peterx@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
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>
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>
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>
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>
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>
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>
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>
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>
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
