On 12/14/18 4:55 PM, Daniel P. Berrangé wrote:
> On Fri, Dec 14, 2018 at 04:42:12PM +0100, Michal Privoznik wrote:
>> On 12/14/18 2:07 PM, Daniel P. Berrangé wrote:
>>> The QEMU command line arguments are very long and currently all written
>>> on a single line to /var/log/libvirt/qemu/$GUEST.log. This introduces
>>> logic to add line breaks after every env variable and "-" optional
>>> argument, and every positional argument. This will create a clearer log
>>> file, which will in turn present better in bug reports when people cut +
>>> paste from the log into a bug comment.
>>>
>>> An example log file entry now looks like this:
>>>
>>> 2018-12-14 12:57:03.677+0000: starting up libvirt version: 5.0.0, qemu version: 3.0.0qemu-3.0.0-1.fc29, kernel: 4.19.5-300.fc29.x86_64, hostname: localhost.localdomain
>>> LC_ALL=C \
>>> PATH=/usr/local/bin:/usr/local/sbin:/usr/bin:/usr/sbin \
>>> HOME=/home/berrange \
>>> USER=berrange \
>>> LOGNAME=berrange \
>>> QEMU_AUDIO_DRV=none \
>>> /usr/bin/qemu-system-ppc64 \
>>> -name guest=guest,debug-threads=on \
>>> -S \
>>> -object secret,id=masterKey0,format=raw,file=/home/berrange/.config/libvirt/qemu/lib/domain-33-guest/master-key.aes \
>>> -machine pseries-2.10,accel=tcg,usb=off,dump-guest-core=off \
>>> -m 1024 \
>>> -realtime mlock=off \
>>> -smp 1,sockets=1,cores=1,threads=1 \
>>> -uuid c8a74977-ab18-41d0-ae3b-4041c7fffbcd \
>>> -display none \
>>> -no-user-config \
>>> -nodefaults \
>>> -chardev socket,id=charmonitor,fd=23,server,nowait \
>>> -mon chardev=charmonitor,id=monitor,mode=control \
>>> -rtc base=utc \
>>> -no-shutdown \
>>> -boot strict=on \
>>> -device qemu-xhci,id=usb,bus=pci.0,addr=0x1 \
>>> -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x2 \
>>> -sandbox on,obsolete=deny,elevateprivileges=deny,spawn=deny,resourcecontrol=deny \
>>> -msg timestamp=on
>>> 2018-12-14 12:57:03.730+0000: shutting down, reason=failed
>>>
>>> Signed-off-by: Daniel P. Berrangé <berrange@xxxxxxxxxx>
>>> ---
>>> docs/internals/command.html.in | 2 +-
>>> src/bhyve/bhyve_driver.c | 4 +-
>>> src/qemu/qemu_driver.c | 2 +-
>>> src/qemu/qemu_interface.c | 2 +-
>>> src/qemu/qemu_process.c | 2 +-
>>> src/security/security_apparmor.c | 2 +-
>>> src/util/vircommand.c | 19 ++++++++--
>>> src/util/vircommand.h | 2 +-
>>> src/util/virfirewall.c | 2 +-
>>> tests/bhyvexml2argvtest.c | 4 +-
>>> tests/commanddata/test26.log | 1 +
>>> tests/commandtest.c | 64 +++++++++++++++++++++++++++++++-
>>> tests/qemuxml2argvtest.c | 2 +-
>>> tests/storagepoolxml2argvtest.c | 2 +-
>>> tests/storagevolxml2argvtest.c | 4 +-
>>> 15 files changed, 95 insertions(+), 19 deletions(-)
>>> create mode 100644 tests/commanddata/test26.log
>>>
>>
>>
>>> @@ -1991,11 +1993,22 @@ virCommandToString(virCommandPtr cmd)
>>> virBufferAdd(&buf, cmd->env[i], eq - cmd->env[i]);
>>> virBufferEscapeShell(&buf, eq);
>>> virBufferAddChar(&buf, ' ');
>>> + if (linebreaks)
>>> + virBufferAddLit(&buf, "\\\n");
>>> }
>>> virBufferEscapeShell(&buf, cmd->args[0]);
>>> for (i = 1; i < cmd->nargs; i++) {
>>> virBufferAddChar(&buf, ' ');
>>> + if (linebreaks) {
>>> + /* Line break if this is a --arg or if
>>> + * the previous arg was a positional option
>>> + */
>>> + if (cmd->args[i][0] == '-' ||
>>> + !prevopt)
>>> + virBufferAddLit(&buf, "\\\n");
>>> + }
>>> virBufferEscapeShell(&buf, cmd->args[i]);
>>> + prevopt = (cmd->args[i][0] == '-');
>>
>> Unfortunately, cmd->args[i] can be NULL here. So I guess this needs to
>> look slightly different:
>
> Hmm, what scenario would make that happen ? I didn't get that
> failure in the test suite.
Are you running against the latest HEAD?
Program received signal SIGSEGV, Segmentation fault.
0x000055555563040b in virCommandToString (cmd=0x555555964b10, linebreaks=false) at util/vircommand.c:2012
2012 prevopt = (cmd->args[i][0] == '-');
virCommandToString 1 $ bt
#0 0x000055555563040b in virCommandToString (cmd=0x555555964b10, linebreaks=false) at util/vircommand.c:2012
#1 0x0000555555587c0c in testCompareXMLToArgvFiles (shouldFail=false, poolxml=0x555555951990 "/home/zippy/work/libvirt/libvirt.git/tests/storagepoolxml2xmlin/pool-dir.xml", volxml=0x5555559582e0 "/home/zippy/work/libvirt/libvirt.git/tests/storagevolxml2xmlin/vol-qcow2-zerocapacity.xml", inputpoolxml=0x0, inputvolxml=0x0, cmdline=0x555555958350 "/home/zippy/work/libvirt/libvirt.git/tests/storagevolxml2argvdata/qcow2-zerocapacity.argv", flags=0, parse_flags=0) at storagevolxml2argvtest.c:107
#2 0x0000555555587fee in testCompareXMLToArgvHelper (data=0x7fffffffd4f0) at storagevolxml2argvtest.c:190
#3 0x0000555555588bc1 in virTestRun (title=0x5555556b4e30 "Storage Vol XML-2-argv qcow2-zerocapacity", body=0x555555587d86 <testCompareXMLToArgvHelper>, data=0x7fffffffd4f0) at testutils.c:176
#4 0x0000555555588508 in mymain () at storagevolxml2argvtest.c:259
#5 0x000055555558ac49 in virTestMain (argc=1, argv=0x7fffffffd798, func=0x555555588056 <mymain>) at testutils.c:1114
#6 0x0000555555588a08 in main (argc=1, argv=0x7fffffffd798) at storagevolxml2argvtest.c:307
virCommandToString 1 $ p cmd->args[i]
$1 = 0x0
virCommandToString 1 $ p i
$2 = 6
This happens because info.path or vol->target.path in virStorageBackendCreateQemuImgCmdFromVol() is NULL. Later, info.path is added to cmd on line 1182:
virCommandAddArg(cmd, info.path);
One can argue that the bug is in fact that info.path is NULL and it may very well be so, but I think the following should not lead to a crash either:
cmd = virCommandNew("/bin/bash");
virCommandAddArg(cmd, NULL);
virCommanRun(cmd);
Michal
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