Re: [PATCH v2 0/3] scripts/qemu-gdb: Make coroutine dumps to work with coredumps

[Kevin Wolf]

Am 12.12.2024 um 21:47 hat Peter Xu geschrieben:
> v1: https://lore.kernel.org/r/20241211201739.1380222-1-peterx@redhat.com
> 
> Changelog: in previous v1, I got a wrong cut-off accident in commit
> message, which is now fixed (along with some small touchup elsewhere).
> When at it, I also tried to make it look even better to be as close as gdb
> bt, so it looks like this now:
> 
>   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> ()
> 
> Coroutines are used in many cases in block layers. It's also used in live
> migration when on destination side, and it'll be handy to diagnose crashes
> within a coroutine when we want to also know what other coroutines are
> doing.
> 
> This series adds initial support for that, not pretty but it should start
> working.  Since we can't use the trick to modify registers on the fly in
> non-live gdb sessions, we do manual unwinds.
> 
> One thing to mention is there's a similar but more generic solution
> mentioned on the list from Niall:
> 
> https://lore.kernel.org/r/f0ebccca-7a17-4da8-ac4a-71cf6d69abc3@mtasv.net
> 
> That adds more dependency on both gdb and qemu in the future, however more
> generic.  So this series is an intermediate quick solution as for now,
> which should work for most older qemu/gdb binaries too.
> 
> Thanks,
> 
> Peter Xu (3):
>   scripts/qemu-gdb: Always do full stack dump for python errors
>   scripts/qemu-gdb: Simplify fs_base fetching for coroutines
>   scripts/qemu-gdb: Support coroutine dumps in coredumps

Thanks, applied to the block branch.

Kevin