On 5/14/19 5:24 PM, Ilias Stamatis wrote:
On Tue, May 14, 2019 at 5:04 PM Michal Privoznik <mprivozn@redhat.com> wrote:
On 5/14/19 12:50 PM, Ilias Stamatis wrote:
On Tue, May 14, 2019 at 12:40 PM John Ferlan <jferlan@redhat.com> wrote:
On 5/13/19 9:04 AM, Ilias Stamatis wrote:
On Mon, May 13, 2019 at 2:38 PM Michal Privoznik <mprivozn@redhat.com> wrote:
On 5/13/19 1:26 AM, Ilias Stamatis wrote: > Return the number of disks present in the configuration of the test > domain when called with @errors as NULL and @maxerrors as 0. > > Otherwise report an error for every second disk, assigning available > error codes in a cyclic order. > > Signed-off-by: Ilias Stamatis <stamatis.iliass@gmail.com> > --- > src/test/test_driver.c | 42 ++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 42 insertions(+) > > diff --git a/src/test/test_driver.c b/src/test/test_driver.c > index a06d1fc402..527c2f5d3b 100644 > --- a/src/test/test_driver.c > +++ b/src/test/test_driver.c > @@ -3046,6 +3046,47 @@ static int testDomainSetAutostart(virDomainPtr domain, > return 0; > } > > +static int testDomainGetDiskErrors(virDomainPtr dom, > + virDomainDiskErrorPtr errors, > + unsigned int maxerrors, > + unsigned int flags) > +{
[...]
> + n++; > + } > + ret = n; > + } > + > + cleanup: > + virDomainObjEndAPI(&vm); > + if (ret < 0) { > + for (i = 0; i < n; i++) > + VIR_FREE(errors[i].disk); > + }
The above got changed to :
+ cleanup: + virDomainObjEndAPI(&vm); + if (ret < 0) { + for (i = 0; i < MIN(vm->def->ndisks, maxerrors); i++) + VIR_FREE(errors[i].disk); + }
I think this change is incorrect and a bug lies in here.
If VIR_STRDUP fails above, memory for less than MIN(vm->def->ndisks, maxerrors) will have been allocated, and then in the cleanup code we'll call VIR_FREE with pointers that haven't been previously allocated.
That isn't a problem. User has to passed an array that we can touch. If they store some data in it, well, their fault - how are we supposed to return anything if we can't touch the array?
I'm not sure I understand exactly what you mean.
We can touch the array of course.
What I'm saying is that we allocate memory with VIR_STRDUP for each errors[i].disk, but if the call fails we free this memory on our own.
However how it is implemented now we might call VIR_FREE on pointers for which we have *not* allocated any memory.
Because in the first loop, VIR_STRDUP might fail and send us to "cleanup". But then on cleanup we iterate over the whole errors array.
Isn't this incorrect? Do I understand something wrong?
Ah, now I get it. If user passes an array that is not zeroed out then we might end up passing a random pointer to free(). How about this then? if (ret < 0) { while (i > 0) VIR_FREE(errors[i--].disk); } Michal