diff options
Diffstat (limited to 'results/classifier/gemma3:12b/debug/1671876')
| -rw-r--r-- | results/classifier/gemma3:12b/debug/1671876 | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/results/classifier/gemma3:12b/debug/1671876 b/results/classifier/gemma3:12b/debug/1671876 new file mode 100644 index 000000000..00351a29e --- /dev/null +++ b/results/classifier/gemma3:12b/debug/1671876 @@ -0,0 +1,69 @@ + +qemu 2.7.0 segfaults in qemu_co_queue_run_restart() + +I've been experiencing frequent segfaults lately with qemu 2.7.0 running Ubuntu 16.04 guests. The crash usually happens in qemu_co_queue_run_restart(). I haven't seen this so far with any other guests or distros. + +Here is one back trace I obtained from one of the crashing VMs. + +------------------------------------------------------------------------------------------------- +(gdb) bt +#0 qemu_co_queue_run_restart (co=0x7fba8ff05aa0) at /build/pb-qemu-pssKUp/pb-qemu-2.7.0/util/qemu-coroutine-lock.c:59 +#1 0x000055c1656f39a9 in qemu_coroutine_enter (co=0x7fba8ff05aa0) at /build/pb-qemu-pssKUp/pb-qemu-2.7.0/util/qemu-coroutine.c:119 +#2 0x000055c1656f3e74 in qemu_co_queue_run_restart (co=0x7fba8dd20430) at /build/pb-qemu-pssKUp/pb-qemu-2.7.0/util/qemu-coroutine-lock.c:60 +#3 0x000055c1656f39a9 in qemu_coroutine_enter (co=0x7fba8dd20430) at /build/pb-qemu-pssKUp/pb-qemu-2.7.0/util/qemu-coroutine.c:119 +#4 0x000055c1656f3e74 in qemu_co_queue_run_restart (co=0x7fba8dd14ea0) at /build/pb-qemu-pssKUp/pb-qemu-2.7.0/util/qemu-coroutine-lock.c:60 +#5 0x000055c1656f39a9 in qemu_coroutine_enter (co=0x7fba8dd14ea0) at /build/pb-qemu-pssKUp/pb-qemu-2.7.0/util/qemu-coroutine.c:119 +#6 0x000055c1656f3e74 in qemu_co_queue_run_restart (co=0x7fba80c11dc0) at /build/pb-qemu-pssKUp/pb-qemu-2.7.0/util/qemu-coroutine-lock.c:60 +#7 0x000055c1656f39a9 in qemu_coroutine_enter (co=0x7fba80c11dc0) at /build/pb-qemu-pssKUp/pb-qemu-2.7.0/util/qemu-coroutine.c:119 +#8 0x000055c1656f3e74 in qemu_co_queue_run_restart (co=0x7fba8dd0bd70) at /build/pb-qemu-pssKUp/pb-qemu-2.7.0/util/qemu-coroutine-lock.c:60 +#9 0x000055c1656f39a9 in qemu_coroutine_enter (co=0x7fba8dd0bd70) at /build/pb-qemu-pssKUp/pb-qemu-2.7.0/util/qemu-coroutine.c:119 +#10 0x000055c1656f3fa0 in qemu_co_enter_next (queue=queue@entry=0x55c1669e75e0) at /build/pb-qemu-pssKUp/pb-qemu-2.7.0/util/qemu-coroutine-lock.c:106 +#11 0x000055c165692060 in timer_cb (blk=0x55c1669e7590, is_write=<optimized out>) at /build/pb-qemu-pssKUp/pb-qemu-2.7.0/block/throttle-groups.c:400 +#12 0x000055c16564f615 in timerlist_run_timers (timer_list=0x55c166a53e80) at /build/pb-qemu-pssKUp/pb-qemu-2.7.0/qemu-timer.c:528 +#13 0x000055c16564f679 in timerlistgroup_run_timers (tlg=tlg@entry=0x55c167c81cf8) at /build/pb-qemu-pssKUp/pb-qemu-2.7.0/qemu-timer.c:564 +#14 0x000055c16564ff47 in aio_dispatch (ctx=ctx@entry=0x55c167c81bb0) at /build/pb-qemu-pssKUp/pb-qemu-2.7.0/aio-posix.c:357 +#15 0x000055c1656500e8 in aio_poll (ctx=0x55c167c81bb0, blocking=<optimized out>) at /build/pb-qemu-pssKUp/pb-qemu-2.7.0/aio-posix.c:479 +#16 0x000055c1654b1c79 in iothread_run (opaque=0x55c167c81960) at /build/pb-qemu-pssKUp/pb-qemu-2.7.0/iothread.c:46 +#17 0x00007fbc4b64f0a4 in allocate_stack (stack=<synthetic pointer>, pdp=<synthetic pointer>, attr=0x0) at allocatestack.c:416 +#18 __pthread_create_2_1 (newthread=<error reading variable: Cannot access memory at address 0xffffffffffffff48>, attr=<error reading variable: Cannot access memory at address 0xffffffffffffff40>, + start_routine=<error reading variable: Cannot access memory at address 0xffffffffffffff58>, arg=<error reading variable: Cannot access memory at address 0xffffffffffffff50>) at pthread_create.c:539 +Backtrace stopped: Cannot access memory at address 0x8 +------------------------------------------------------------------------------------------------- + +The code that crashes is this +------------------------------------------------------------------------------------------------- +void qemu_co_queue_run_restart(Coroutine *co) +{ + Coroutine *next; + + trace_qemu_co_queue_run_restart(co); + while ((next = QSIMPLEQ_FIRST(&co->co_queue_wakeup))) { + QSIMPLEQ_REMOVE_HEAD(&co->co_queue_wakeup, co_queue_next); <--- Crash occurs here this time + qemu_coroutine_enter(next); + } +} +------------------------------------------------------------------------------------------------- + +Expanding the macro QSIMPLEQ_REMOVE_HEAD gives us +------------------------------------------------------------------------------------------------- +#define QSIMPLEQ_REMOVE_HEAD(head, field) do { \ + if (((head)->sqh_first = (head)->sqh_first->field.sqe_next) == NULL)\ + (head)->sqh_last = &(head)->sqh_first; \ +} while (/*CONSTCOND*/0) +------------------------------------------------------------------------------------------------- + +which corrsponds to +------------------------------------------------------------------------------------------------- +if (((&co->co_queue_wakeup)->sqh_first = (&co->co_queue_wakeup)->sqh_first->co_queue_next.sqe_next) == NULL)\ + (&co->co_queue_wakeup)->sqh_last = &(&co->co_queue_wakeup)->sqh_first; +------------------------------------------------------------------------------------------------- + +Debugging the list we see +------------------------------------------------------------------------------------------------- +(gdb) print *(&co->co_queue_wakeup->sqh_first) +$6 = (struct Coroutine *) 0x1000 +(gdb) print *(&co->co_queue_wakeup->sqh_first->co_queue_next) +Cannot access memory at address 0x1030 +------------------------------------------------------------------------------------------------- + +So the data in co->co_queue_wakeup->sqh_first is corrupted and represents an invalid address. Any idea why is that? \ No newline at end of file |