[libcamera-devel] [RFC PATCH 09/10] libcamera: pipeline: raspberrypi: DmaHeaps: Use ScopedFD for a file descriptor

[Hirokazu Honda]

Hi Laurent,

On Mon, Jun 7, 2021 at 3:48 AM Laurent Pinchart <
laurent.pinchart at ideasonboard.com> wrote:

> Hi Hiro,
>
> Thank you for the patch.
>
> On Thu, Apr 15, 2021 at 05:38:42PM +0900, Hirokazu Honda wrote:
> > DmaHeaps owns a file descriptor for a dma handle. It should be
> > managed by ScopedFD to avoid the leakage. Furthermore,
> > DmaHeaps::alloc() creates a new file descriptor and the returned
> > file descriptor is owned by a caller. This also clarifies it by
> > changing the returned value to ScopedFD.
> >
> > Signed-off-by: Hirokazu Honda <hiroh at chromium.org>
> > ---
> >  .../pipeline/raspberrypi/dma_heaps.cpp        | 23 ++++++++-----------
> >  .../pipeline/raspberrypi/dma_heaps.h          | 10 ++++----
> >  .../pipeline/raspberrypi/raspberrypi.cpp      |  7 ++++--
> >  3 files changed, 21 insertions(+), 19 deletions(-)
> >
> > diff --git a/src/libcamera/pipeline/raspberrypi/dma_heaps.cpp
> b/src/libcamera/pipeline/raspberrypi/dma_heaps.cpp
> > index 4d5dd6cb..d5b000b8 100644
> > --- a/src/libcamera/pipeline/raspberrypi/dma_heaps.cpp
> > +++ b/src/libcamera/pipeline/raspberrypi/dma_heaps.cpp
> > @@ -35,7 +35,6 @@ LOG_DECLARE_CATEGORY(RPI)
> >  namespace RPi {
> >
> >  DmaHeap::DmaHeap()
> > -     : dmaHeapHandle_(-1)
> >  {
> >       for (const char *name : heapNames) {
> >               int ret = ::open(name, O_RDWR, 0);
> > @@ -46,49 +45,47 @@ DmaHeap::DmaHeap()
> >                       continue;
> >               }
> >
> > -             dmaHeapHandle_ = ret;
> > +             dmaHeapHandle_ = ScopedFD(ret);
> >               break;
> >       }
> >
> > -     if (dmaHeapHandle_ < 0)
> > +     if (!dmaHeapHandle_.isValid())
> >               LOG(RPI, Error) << "Could not open any dmaHeap device";
> >  }
> >
> >  DmaHeap::~DmaHeap()
> >  {
> > -     if (dmaHeapHandle_ > -1)
> > -             ::close(dmaHeapHandle_);
> >  }
> >
> > -FileDescriptor DmaHeap::alloc(const char *name, std::size_t size)
> > +ScopedFD DmaHeap::alloc(const char *name, std::size_t size)
> >  {
> >       int ret;
> >
> >       if (!name)
> > -             return FileDescriptor();
> > +             return ScopedFD();
> >
> >       struct dma_heap_allocation_data alloc = {};
> >
> >       alloc.len = size;
> >       alloc.fd_flags = O_CLOEXEC | O_RDWR;
> >
> > -     ret = ::ioctl(dmaHeapHandle_, DMA_HEAP_IOCTL_ALLOC, &alloc);
> > +     ret = ::ioctl(dmaHeapHandle_.get(), DMA_HEAP_IOCTL_ALLOC, &alloc);
> >
> >       if (ret < 0) {
> >               LOG(RPI, Error) << "dmaHeap allocation failure for "
> >                               << name;
> > -             return FileDescriptor();
> > +             return ScopedFD();
> >       }
> >
> > -     ret = ::ioctl(alloc.fd, DMA_BUF_SET_NAME, name);
> > +     ScopedFD allocFd(alloc.fd);
> > +     ret = ::ioctl(allocFd.get(), DMA_BUF_SET_NAME, name);
> >       if (ret < 0) {
> >               LOG(RPI, Error) << "dmaHeap naming failure for "
> >                               << name;
> > -             ::close(alloc.fd);
> > -             return FileDescriptor();
> > +             return ScopedFD();
> >       }
> >
> > -     return FileDescriptor(std::move(alloc.fd));
> > +     return allocFd;
> >  }
> >
> >  } /* namespace RPi */
> > diff --git a/src/libcamera/pipeline/raspberrypi/dma_heaps.h
> b/src/libcamera/pipeline/raspberrypi/dma_heaps.h
> > index 79f39c51..c49772df 100644
> > --- a/src/libcamera/pipeline/raspberrypi/dma_heaps.h
> > +++ b/src/libcamera/pipeline/raspberrypi/dma_heaps.h
> > @@ -7,7 +7,9 @@
> >  #ifndef __LIBCAMERA_PIPELINE_RASPBERRYPI_DMA_HEAPS_H__
> >  #define __LIBCAMERA_PIPELINE_RASPBERRYPI_DMA_HEAPS_H__
> >
> > -#include <libcamera/file_descriptor.h>
> > +#include <cstddef>
> > +
> > +#include <libcamera/scoped_file_descriptor.h>
> >
> >  namespace libcamera {
> >
> > @@ -18,11 +20,11 @@ class DmaHeap
> >  public:
> >       DmaHeap();
> >       ~DmaHeap();
> > -     bool isValid() const { return dmaHeapHandle_ > -1; }
> > -     FileDescriptor alloc(const char *name, std::size_t size);
> > +     bool isValid() const { return dmaHeapHandle_.isValid(); }
> > +     ScopedFD alloc(const char *name, std::size_t size);
> >
> >  private:
> > -     int dmaHeapHandle_;
> > +     ScopedFD dmaHeapHandle_;
> >  };
> >
> >  } /* namespace RPi */
> > diff --git a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
> b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
> > index f22e286e..0075fdb1 100644
> > --- a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
> > +++ b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
> > @@ -1256,10 +1256,13 @@ int RPiCameraData::configureIPA(const
> CameraConfiguration *config)
> >
> >       /* Allocate the lens shading table via dmaHeap and pass to the
> IPA. */
> >       if (!lsTable_.isValid()) {
> > -             lsTable_ = dmaHeap_.alloc("ls_grid",
> ipa::RPi::MaxLsGridSize);
> > -             if (!lsTable_.isValid())
> > +             ScopedFD scopedFD =
> > +                     dmaHeap_.alloc("ls_grid", ipa::RPi::MaxLsGridSize);
> > +             if (!scopedFD.isValid())
> >                       return -ENOMEM;
> >
> > +             lsTable_ = FileDescriptor(scopedFD.release());
>
> This isn't very nice. One option could be to add a FileDescriptor
> constructor that takes a ScopedFD. What do you think ?
>
>
That sounds good to me.
-Hiro


> > +
> >               /* Allow the IPA to mmap the LS table via the file
> descriptor. */
> >               /*
> >                * \todo Investigate if mapping the lens shading table
> buffer
>
> --
> Regards,
>
> Laurent Pinchart
>
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