Messages in this thread | | | Date | Thu, 28 Apr 2016 16:31:28 +0200 | From | Andrey Gursky <> | Subject | Re: [PATCH] drivers/base: wrong return value of dmam_declare_coherent_memory |
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Vyacheslav,
thanks for your patch.
For now it introduces a new bug.
Vyacheslav Yurkov <uvv.mail <at> gmail.com> writes:
> > Hi guys, > I found an issue in managed version of dma_declare_coherent_memory, > i.e. in dmam_declare_coherent_memory. It looks like the return value > of dma_declare_coherent_memory is zero in case of error and a > requested flag on success,
You should take this into account and not ignore the value of rc at all by using flags instead, which is not being altered by dma_declare_coherent_memory() making the latter appear to succeed always.
> which dmam_* version doesn't take into > account and this leads to leaking of resources. > > --- > Yours sincerely, > Vyacheslav V. Yurkov > > P.S.: I'm not subscribed to the maillist, so please include me in CC > when responding to this Email. > > --- > --- linux-4.5.2/drivers/base/dma-mapping.c.orig 2016-04-20 > 08:46:35.000000000 +0200 > +++ linux-4.5.2/drivers/base/dma-mapping.c 2016-04-28 10:15:34.295080491 > +0200 > <at> <at> -198,10 +198,15 <at> <at> int dmam_declare_coherent_memory(struct > > rc = dma_declare_coherent_memory(dev, phys_addr, device_addr, size, > flags); > - if (rc == 0) > + > + if ((flags & DMA_MEMORY_MAP) == DMA_MEMORY_MAP || > + (flags & DMA_MEMORY_IO) == DMA_MEMORY_IO) { > devres_add(dev, res); > - else > + rc = 0; > + } else { > devres_free(res); > + rc = -ENOMEM; > + } > > return rc; > } > > Signed-off-by: Vyacheslav Yurkov <uvv.mail <at> gmail.com> >
Best Regards, Andrey
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