On Sun, Apr 17, 2022 at 11:13:50PM +0200, Fabio M. De Francesco wrote:
> On domenica 17 aprile 2022 22:42:00 CEST Jaehee Park wrote:
> > On Sun, Apr 17, 2022 at 11:16:38PM +0300, Pavel Skripkin wrote:
> > > Hi Jaehee,
> > >
> > > On 4/17/22 23:14, Jaehee Park wrote:
> > > > My understanding of Pavel's response is the free_bss_buf member of
> the
> > > > pmlmepriv structure wasn't being used anywhere and that the
> > > > rtw_free_mlme_riv_ie_data function frees the memory of the pmlmepriv
> > > > structure so the second check is redundant.
> > > >
> > > > However, as Fabio said, the free_bss_buf member is being used and
> pbuf
> > > > memory is not being freed.
> > > > So I'll revert the patch as it was originally (which was just
> removing
> > > > the {} around the single if statement).
>
> No, Jaehee. This is not what I said :)
>
> > > >
> > >
> > > Why just `pbuf` allocation can't be removed? This memory is just
> unused,
> > > isn't it?
>
> What Pavel said is what I said, but using a different argumentation.
>
> > >
> > >
> > > With regards,
> > > Pavel Skripkin
> >
> >
> > The free_bss_buf member is unused.
>
> Correct.
>
> > So it can just be removed right?
>
> No.
>
>
> > I guess I'm confused by what Pablo is saying about causing a memory
> > leak
>
> A memory leak is caused when you allocate some memory and then you lose any
> reference to its address so that it cannot be freed. Right?
>
> > by getting rid of the pointer to the memory allocated by pbuf.
>
> No.
>
> > Sorry if I misunderstood.
>
> No problem. Let's rewind...
>
> "pbuf" is assigned with the address of some memory allocated with a call to
> vzalloc(). Since "pbuf" is a local variable, you see that the above-
> mentioned address is stored in free_bss_buf using the line "pmlmepriv-
> >free_bss_buf = pbuf". Is it clear?
>
> Well, you decided to delete the line that calls vfree(pmlmepriv-
> >free_bss_buf). At this point you have that memory leak.
>
> Pavel noted that pmlmepriv->free_bss_buf is unused, but it contains the
> address of a region of memory that was allocated for no purpose.
>
> Therefore, a correct patch should also remove the allocation that was made
> using kzalloc(). If you merely remove the line with vfree() you cause a
> memory leak.
Hi Fabio, Thank you so much for explaining this so patiently!
This makes sense. I'll remove the pbuf vzalloc.
I think I was having trouble because of of how pnetwork was defined
in this function. I'll have to think a little more about how to
intialize it.
Thanks,
Jaehee
>
> Please don't revert your patch. Just fix it with a new version that also
> delete the line where "pbuf" is assigned with the value returned by
> kzalloc().
>
> I hope that now I've been clearer.
>
> Thanks,
>
> Fabio
>
> > Thanks,
> > Jaehee
> >
>
>
>
>
