Re: [Qemu-devel] [PATCH 5/9] tests/libqos/usb: Clean up string interpolation into QMP input

[Markus Armbruster <armbru@redhat.com>]

Eric Blake <eblake@redhat.com> writes:

> On 07/21/2017 08:53 AM, Markus Armbruster wrote:
>> Leaving interpolation into JSON to qmp() is more robust than building
>> QMP input manually, as explained in the previous commit.
>> 
>> The case in usb_test_hotplug() slightly more complicated: it
>
> s/()/() is/

Will fix.

>> interpolates *into* JSON values.  Clean it up by building the values
>> separately, so we can again leave interpolation to qmp().
>> 
>> Signed-off-by: Markus Armbruster <armbru@redhat.com>
>> ---
>>  tests/libqos/usb.c | 30 ++++++++++++++----------------
>>  1 file changed, 14 insertions(+), 16 deletions(-)
>> 
>> diff --git a/tests/libqos/usb.c b/tests/libqos/usb.c
>> index 0cdfaec..f88d4a6 100644
>> --- a/tests/libqos/usb.c
>> +++ b/tests/libqos/usb.c
>> @@ -40,18 +40,20 @@ void uhci_port_test(struct qhc *hc, int port, uint16_t expect)
>>  void usb_test_hotplug(const char *hcd_id, const int port,
>>                        void (*port_check)(void))
>>  {
>> +    char id[32];
>> +    char *bus;
>>      QDict *response;
>> -    char  *cmd;
>>  
>> -    cmd = g_strdup_printf("{'execute': 'device_add',"
>> -                          " 'arguments': {"
>> -                          "   'driver': 'usb-tablet',"
>> -                          "   'port': '%d',"
>> -                          "   'bus': '%s.0',"
>> -                          "   'id': 'usbdev%d'"
>> -                          "}}", port, hcd_id, port);
>> -    response = qmp(cmd);
>> -    g_free(cmd);
>> +    sprintf(id, "usbdev%d", port);
>
> I know this fits, but do any of our compilers issue dumb warnings about
> possible buffer overflow?  I guess we'll deal with that if someone
> reports a problem.

We do similar things elsewhere, just grep for sprintf.

> Reviewed-by: Eric Blake <eblake@redhat.com>

Thanks!