[libvirt] Crash when using python-libvirt setSchedulerParameters
Michal Privoznik
mprivozn at redhat.com
Thu Mar 27 15:14:41 UTC 2014
On 27.03.2014 16:01, Brian Rak wrote:
>
> On 3/27/2014 10:54 AM, Brian Rak wrote:
>>
>> On 3/25/2014 6:50 AM, Michal Privoznik wrote:
>>> On 24.03.2014 21:45, Brian Rak wrote:
>>>> I'm seeing a very weird (and somewhat reproducable) crash in
>>>> setSchedulerParameters. The backtrace looks like this:
>>>>
>>>> *** glibc detected *** python2.7: free(): invalid pointer:
>>>> 0x000000000152bc48 ***
>>>> ======= Backtrace: =========
>>>> /lib64/libc.so.6(+0x76166)[0x7faa9e991166]
>>>> /usr/lib64/python2.7/site-packages/libvirtmod.so(virFree+0x29)[0x7faa9887bfe9]
>>>>
>>>>
>>>> /lib/libvirt.so.0(virTypedParamsClear+0x54)[0x7faa98342fe4]
>>>> /lib/libvirt.so.0(virTypedParamsFree+0x1e)[0x7faa9834302e]
>>>> /usr/lib64/python2.7/site-packages/libvirtmod.so(+0x1b4dc)[0x7faa9886c4dc]
>>>>
>>>> /usr/lib64/libpython2.7.so.1.0(PyEval_EvalFrameEx+0x5629)[0x7faa9f63a129]
>>>>
>>>> /usr/lib64/libpython2.7.so.1.0(PyEval_EvalFrameEx+0x68e8)[0x7faa9f63b3e8]
>>>>
>>>> /usr/lib64/libpython2.7.so.1.0(PyEval_EvalCodeEx+0x8ae)[0x7faa9f63bd5e]
>>>> /usr/lib64/libpython2.7.so.1.0(PyEval_EvalCode+0x32)[0x7faa9f63be72]
>>>> /usr/lib64/libpython2.7.so.1.0(+0xff25c)[0x7faa9f65625c]
>>>> /usr/lib64/libpython2.7.so.1.0(PyRun_FileExFlags+0x90)[0x7faa9f656330]
>>>> /usr/lib64/libpython2.7.so.1.0(PyRun_SimpleFileExFlags+0xef)[0x7faa9f6578cf]
>>>>
>>>>
>>>> /usr/lib64/libpython2.7.so.1.0(Py_Main+0xc56)[0x7faa9f6693f6]
>>>> /lib64/libc.so.6(__libc_start_main+0xfd)[0x7faa9e939d1d]
>>>> python2.7[0x400649]
>>>>
>>>>
>>>> I am using:
>>>> Python2.7
>>>> Python-Libvirt 1.2.2 with the "[PATCH libvirt-python 1/2]
>>>> setPyVirTypedParameter: Copy full field name" patch.
>>>> Libvirt 1.2.1
>>>
>>> Is the following patch applied as well?
>>>
>>> commit 69c4600d61fa74c4977d2471a29fb73f0fe5edb0
>>> Author: Michal Privoznik <mprivozn at redhat.com>
>>> AuthorDate: Tue Mar 18 09:20:00 2014 +0100
>>> Commit: Michal Privoznik <mprivozn at redhat.com>
>>> CommitDate: Tue Mar 18 14:43:10 2014 +0100
>>>
>>> setPyVirTypedParameter: free whole return variable on error
>>>
>>> The @ret value is built in a loop. However, if in one iteration
>>> there's an error, we should free all the fields built so far. For
>>> instance, if there's an error and the previous item was
>>> type of VIR_TYPED_PARAM_STRING we definitely must free it.
>>>
>>> Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
>>>
>>>
>>> Can you install debuginfo so we see the full stack trace?
>>>
>>> Michal
>> Unfortunately, even with that patch I'm still seeing crashes.
>>
>> Apparently, this crash only happens when running normally (it doesn't
>> crash when running under gdb). I created a core dump, and have what
>> might be a better call stack:
>>
>> (gdb) where
>> #0 0x00007f96047cd925 in raise () from /lib64/libc.so.6
>> #1 0x00007f96047cf105 in abort () from /lib64/libc.so.6
>> #2 0x00007f960480b837 in __libc_message () from /lib64/libc.so.6
>> #3 0x00007f9604811166 in malloc_printerr () from /lib64/libc.so.6
>> #4 0x00007f95fe6fbff9 in virFree (ptrptr=0x2463918) at
>> libvirt-utils.c:119
>> #5 0x00007f95fe1c2fe4 in virTypedParamsClear (params=<value optimized
>> out>, nparams=5) at util/virtypedparam.c:1147
>> #6 0x00007f95fe1c302e in virTypedParamsFree (params=0x2463800,
>> nparams=<value optimized out>) at util/virtypedparam.c:1166
>> #7 0x00007f95fe6ec4ec in libvirt_virDomainSetSchedulerParameters
>> (self=<value optimized out>, args=<value optimized out>) at
>> libvirt-override.c:975
>> #8 0x00007f96054ba129 in call_function (f=<value optimized out>,
>> throwflag=<value optimized out>) at
>> /usr/src/debug/Python-2.7.6/Python/ceval.c:4098
>> ... truncated
>>
>>
>> This patch corrects the issue. new_params is not guaranteed to have
>> the same number of parameters as params, so we can't use nparams here
>> to free the object.
>>
>> diff --git a/python27-libvirt/libvirt-python-1.2.2/libvirt-override.c
>> b/python27-libvirt/libvi
>> index f8fafa7..9725870 100755
>> --- a/python27-libvirt/libvirt-python-1.2.2/libvirt-override.c
>> +++ b/python27-libvirt/libvirt-python-1.2.2/libvirt-override.c
>> @@ -913,7 +913,7 @@ libvirt_virDomainSetSchedulerParameters(PyObject
>> *self ATTRIBUTE_UNUSED,
>> int i_retval;
>> int nparams = 0;
>> Py_ssize_t size = 0;
>> - virTypedParameterPtr params, new_params = NULL;
>> + virTypedParameterPtr params = NULL, new_params = NULL;
>>
>> if (!PyArg_ParseTuple(args, (char
>> *)"OO:virDomainSetScedulerParameters",
>> &pyobj_domain, &info))
>> @@ -972,7 +972,7 @@ libvirt_virDomainSetSchedulerParameters(PyObject
>> *self ATTRIBUTE_UNUSED,
>>
>> cleanup:
>> virTypedParamsFree(params, nparams);
>> - virTypedParamsFree(new_params, nparams);
>> + virTypedParamsFree(new_params, size);
>> return ret;
>> }
>>
>>
>> I am not sure if the 'params = NULL' change is necessary, but that
>> seemed like a potential bug anyway.
>
>
> Turns out this issue occurs a bunch of other places as well. Better
> patch, fixes all the ones I see:
>
> diff --git a/python27-libvirt/libvirt-python-1.2.2/libvirt-override.c
> b/python27-libvirt/libvirt-python-1.2.2/libvirt-override.c
> --- a/python27-libvirt/libvirt-python-1.2.2/libvirt-override.c
> +++ b/python27-libvirt/libvirt-python-1.2.2/libvirt-override.c
> @@ -913,7 +913,7 @@ libvirt_virDomainSetSchedulerParameters(PyObject
> *self ATTRIBUTE_UNUSED,
> int i_retval;
> int nparams = 0;
> Py_ssize_t size = 0;
> - virTypedParameterPtr params, new_params = NULL;
> + virTypedParameterPtr params = NULL, new_params = NULL;
>
> if (!PyArg_ParseTuple(args, (char
> *)"OO:virDomainSetScedulerParameters",
> &pyobj_domain, &info))
> @@ -972,7 +972,7 @@ libvirt_virDomainSetSchedulerParameters(PyObject
> *self ATTRIBUTE_UNUSED,
>
> cleanup:
> virTypedParamsFree(params, nparams);
> - virTypedParamsFree(new_params, nparams);
> + virTypedParamsFree(new_params, size);
> return ret;
> }
>
> @@ -1063,7 +1063,7 @@ libvirt_virDomainSetBlkioParameters(PyObject *self
> ATTRIBUTE_UNUSED,
> int nparams = 0;
> Py_ssize_t size = 0;
> unsigned int flags;
> - virTypedParameterPtr params, new_params = NULL;
> + virTypedParameterPtr params = NULL, new_params = NULL;
>
> if (!PyArg_ParseTuple(args,
> (char *)"OOi:virDomainSetBlkioParameters",
> @@ -1122,7 +1122,7 @@ libvirt_virDomainSetBlkioParameters(PyObject *self
> ATTRIBUTE_UNUSED,
>
> cleanup:
> virTypedParamsFree(params, nparams);
> - virTypedParamsFree(new_params, nparams);
> + virTypedParamsFree(new_params, size);
> return ret;
> }
>
> @@ -1183,7 +1183,7 @@ libvirt_virDomainSetMemoryParameters(PyObject
> *self ATTRIBUTE_UNUSED,
> int nparams = 0;
> Py_ssize_t size = 0;
> unsigned int flags;
> - virTypedParameterPtr params, new_params = NULL;
> + virTypedParameterPtr params = NULL, new_params = NULL;
>
> if (!PyArg_ParseTuple(args,
> (char *)"OOi:virDomainSetMemoryParameters",
> @@ -1242,7 +1242,7 @@ libvirt_virDomainSetMemoryParameters(PyObject
> *self ATTRIBUTE_UNUSED,
>
> cleanup:
> virTypedParamsFree(params, nparams);
> - virTypedParamsFree(new_params, nparams);
> + virTypedParamsFree(new_params, size);
> return ret;
> }
>
> @@ -1303,7 +1303,7 @@ libvirt_virDomainSetNumaParameters(PyObject *self
> ATTRIBUTE_UNUSED,
> int nparams = 0;
> Py_ssize_t size = 0;
> unsigned int flags;
> - virTypedParameterPtr params, new_params = NULL;
> + virTypedParameterPtr params = NULL, new_params = NULL;
>
> if (!PyArg_ParseTuple(args,
> (char *)"OOi:virDomainSetNumaParameters",
> @@ -1362,7 +1362,7 @@ libvirt_virDomainSetNumaParameters(PyObject *self
> ATTRIBUTE_UNUSED,
>
> cleanup:
> virTypedParamsFree(params, nparams);
> - virTypedParamsFree(new_params, nparams);
> + virTypedParamsFree(new_params, size);
> return ret;
> }
>
> @@ -1424,7 +1424,7 @@ libvirt_virDomainSetInterfaceParameters(PyObject
> *self ATTRIBUTE_UNUSED,
> Py_ssize_t size = 0;
> unsigned int flags;
> const char *device = NULL;
> - virTypedParameterPtr params, new_params = NULL;
> + virTypedParameterPtr params = NULL, new_params = NULL;
>
> if (!PyArg_ParseTuple(args,
> (char *)"OzOi:virDomainSetInterfaceParameters",
> @@ -1487,7 +1487,7 @@ libvirt_virDomainSetInterfaceParameters(PyObject
> *self ATTRIBUTE_UNUSED,
>
> cleanup:
> virTypedParamsFree(params, nparams);
> - virTypedParamsFree(new_params, nparams);
> + virTypedParamsFree(new_params, size);
> return ret;
> }
>
> @@ -4785,7 +4785,7 @@ libvirt_virDomainSetBlockIoTune(PyObject *self
> ATTRIBUTE_UNUSED,
> Py_ssize_t size = 0;
> const char *disk;
> unsigned int flags;
> - virTypedParameterPtr params, new_params = NULL;
> + virTypedParameterPtr params = NULL, new_params = NULL;
>
> if (!PyArg_ParseTuple(args, (char *)"OzOi:virDomainSetBlockIoTune",
> &pyobj_domain, &disk, &info, &flags))
> @@ -4843,7 +4843,7 @@ libvirt_virDomainSetBlockIoTune(PyObject *self
> ATTRIBUTE_UNUSED,
>
> cleanup:
> virTypedParamsFree(params, nparams);
> - virTypedParamsFree(new_params, nparams);
> + virTypedParamsFree(new_params, size);
> return ret;
> }
>
>
That's correct. Can you post it as a actual patch with commit message an
all? I'll merge it then.
Michal
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