On 5/29/19 9:56 AM, Andrey Shinkevich wrote:
>
>
> On 29/05/2019 16:40, John Snow wrote:
>>
>>
>> On 5/29/19 8:22 AM, Andrey Shinkevich wrote:
>>> The uninitialized memory allocated for the command FIFO of the
>>> floppy controller during the VM hardware initialization incurs
>>> many unwanted reports by Valgrind when VM state is being saved.
>>> That verbosity hardens a search for the real memory issues when
>>> the iotests run. Particularly, the patch eliminates 20 unnecessary
>>> reports of the Valgrind tool in the iotest #169.
>>>
>>> Signed-off-by: Andrey Shinkevich <andrey.shinkev...@virtuozzo.com>
>>> ---
>>> hw/block/fdc.c | 4 ++++
>>> 1 file changed, 4 insertions(+)
>>>
>>> diff --git a/hw/block/fdc.c b/hw/block/fdc.c
>>> index 6f19f12..54e470c 100644
>>> --- a/hw/block/fdc.c
>>> +++ b/hw/block/fdc.c
>>> @@ -2647,6 +2647,10 @@ static void fdctrl_realize_common(DeviceState *dev,
>>> FDCtrl *fdctrl,
>>>
>>> FLOPPY_DPRINTF("init controller\n");
>>> fdctrl->fifo = qemu_memalign(512, FD_SECTOR_LEN);
>>> + if (fdctrl->fifo) {
>>> + /* To avoid using the uninitialized memory while saving VM state */
>>> + memset(fdctrl->fifo, 0, FD_SECTOR_LEN);
>>> + }
>>
>> qemu_memalign doesn't look like it can fail (looking at
>> util/oslib-posix); is this conditional necessary?
>>
>> I think you could just:
>>
>> fdctrl->fifo = qemu_memalign(512, FD_SECTOR_LEN);
>> memset(fdctrl->fifo, 0, FD_SECTOR_LEN);
>>
>>> fdctrl->fifo_size = 512;
>>> fdctrl->result_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
>>> fdctrl_result_timer, fdctrl);
>>>
>
> Yes, that's right.
> Thank you, John.
>
> Andrey
>
Thanks for valgrinding QEMU :)
--js
