Escalated to Bugzilla from IssueTracker
Event posted on 09-11-2009 04:53pm EDT by Glen Johnson =Comment: #0================================================= SUDHIR KUMAR <sudhirkumarmalik.com> - ---Problem Description--- migrate_set_speed after a migrate_cancel causes segmentation fault in kvm Contact Information = Sudhir Kumar/sudhirkumarmalik.com ---uname output--- Linux bc1cn3 2.6.18-162.el5 #1 SMP Tue Aug 4 16:24:37 EDT 2009 x86_64 x86_64 x86_64 GNU/Linux Machine Type = HS22 blade ---Steps to Reproduce--- Start a source Vm: Start the target vm: On the source start migration: migrate -d tcp:0:6000 cancel migration (qemu) migrate_cancel (qemu) migrate_set_speed 1g Segmentation fault ---KVM Component Data--- [root@bc1cn3 images]# rpm -qa | grep kvm kmod-kvm-83-105.el5 kvm-83-105.el5 etherboot-zroms-kvm-5.4.4-10.el5 kvm-qemu-img-83-105.el5 kvm-tools-83-105.el5 *Additional Instructions for Sudhir Kumar/sudhirkumarmalik.com: -Post a private note with access information to the machine that the bug is occuring on. Complete description: Source VM: # /usr/libexec/qemu-kvm -hda rhel54-64.raw -m 8192 -smp 4 -net nic -net tap,script=/root/qemu-ifup-breth2 -name 54_64 -vnc :10 -monitor stdio (qemu) migrate -d tcp:0:6000 (qemu) migration_notify_done (qemu) info migrate Migration status: active transferred ram: 3218296 kbytes remaining ram: 5192900 kbytes total ram: 8409100 kbytes (qemu) migrate_cancel migration_notify_done (qemu) info migrate Migration status: cancelled (qemu) migrate_set_speed 1g Segmentation fault Here is the segfault shown in dmesg. qemu-kvm[17043]: segfault at 0000000000000020 rip 0000000000472fa0 rsp 00007fffd54f95d8 error 4 The target VM was started as below. # /usr/libexec/qemu-kvm -hda rhel54-64.raw -m 8192 -smp 4 -net nic -net tap,script=/root/qemu-ifup-breth2 -name 54_64_2 -vnc :11 -monitor stdio -incoming tcp:0:6000 Here is the segfault shown in dmesg. qemu-kvm[17043]: segfault at 0000000000000020 rip 0000000000472fa0 rsp 00007fffd54f95d8 error 4 Generated a core file and ran gdb on it. Here is the backtrace. (gdb) bt #0 0x0000000000472fa0 in fprintf () #1 0x000000000046c97f in fprintf () #2 0x00000000004105f3 in fprintf () #3 0x00000000004655e2 in fprintf () #4 0x000000000040eb1f in fprintf () #5 0x00000000004712e1 in fprintf () #6 0x0000000000409722 in fprintf () #7 0x00000000004ffd7a in fprintf () #8 0x000000000040dbcc in fprintf () #9 0x000000351261d994 in __libc_start_main () from /lib64/libc.so.6 #10 0x0000000000406be9 in fprintf () #11 0x00007fffabdbc808 in ?? () #12 0x0000000000000000 in ?? () I could not grab the corresponding sources hence did not try to look into the code. The issue is not produced when migrate_set_speed is called without calling migrate_cancel prior to it. Please let me know if further information is required. =Comment: #3================================================= Edjunior Barbosa Machado <emachado.ibm.com> - fix segfault in setting migration speed This backport patch (based on kvm-83-105.el5.src.rpm from RHEL5.4 RC3) intends to fix the segfault which occurs when setting a new rate limit after a finished (or canceled/failed) migration. Original patch: http://git.savannah.gnu.org/cgit/qemu.git/commit/?id=0bb05eaff04d30609a98c0dae80bb5dba3e4e799 =Comment: #5================================================= SUDHIR KUMAR <sudhirkumarmalik.com> - Verified the fix and the fault is no more producible. ================================================= Hello Red Hat, please consider the attached backport patch, based on kvm-83-105.el5.src.rpm, which fixed this issue. Thanks for your support. This event sent from IssueTracker by jkachuck [IBM-LTC] issue 341626
Created attachment 360744 [details] set_rate_limit.patch
This is upstream commit 0bb05eaff04d30609a98c0dae80bb5dba3e4e799, not sure why it hasn't been submitted for inclusion. Doing it now, as the patch fixes the problem for me.
Can reproduce in kvm-83-113.el5 Can not reproduce in kvm-83-119.el5
Could not reproduce in kvm-83-139.el5
*** Bug 511376 has been marked as a duplicate of this bug. ***
An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on therefore solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHSA-2010-0271.html