Re: [Qemu-devel] [PATCH 2/3] qemu-img: Use only string options in img_open_opts

[Max Reitz <mreitz@redhat.com>]

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On 2018-05-03 00:00, Eric Blake wrote:
> On 05/02/2018 03:20 PM, Max Reitz wrote:
>> img_open_opts() takes a QemuOpts and converts them to a QDict, so all
>> values therein are strings.  Then it may try to call qdict_get_bool(),
>> however, which will fail with a segmentation fault every time:
> 
> I have no idea if it's worth fixing qdict_get_bool() to at least not
> segfault when called on a non-bool Dict member (but what should it
> return, true or false? or should it abort() for at least a cleaner
> failure than a segfault?)

There's qdict_get_try_bool() which returns a default.  For testing
whether the member is a bool I suppose you can use
qdict_to(QBool, qdict_get(qdict, member)).

Max

> But in the meantime, your fix is correct.
> 
>>
>> $ ./qemu-img info -U --image-opts \
>>      driver=file,filename=/dev/null,force-share=off
>> [1]    27869 segmentation fault (core dumped)  ./qemu-img info -U
>> --image-opts driver=file,filename=/dev/null,force-share=off
>>
>> Fix this by using qdict_get_str() and comparing the value as a string.
>> Also, when adding a force-share value to the QDict, add it as a string
>> so it fits the rest of the dict.
>>
>> Cc: qemu-stable@nongnu.org
>> Signed-off-by: Max Reitz <mreitz@redhat.com>
>> ---
>>   qemu-img.c | 4 ++--
>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>
> 
> Reviewed-by: Eric Blake <eblake@redhat.com>
> 



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