fee0c54e28
dma_buf_map_attachment and dma_buf_vmap can return NULL or
ERR_PTR on a error. This encourages a common buggy pattern in
callers:
sgt = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
if (IS_ERR_OR_NULL(sgt))
return PTR_ERR(sgt);
This causes the caller to return 0 on an error. IS_ERR_OR_NULL
is almost always a sign of poorly-defined error handling.
This patch converts dma_buf_map_attachment to always return
ERR_PTR, and fixes the callers that incorrectly handled NULL.
There are a few more callers that were not checking for NULL
at all, which would have dereferenced a NULL pointer later.
There are also a few more callers that correctly handled NULL
and ERR_PTR differently, I left those alone but they could also
be modified to delete the NULL check.
This patch also converts dma_buf_vmap to always return NULL.
All the callers to dma_buf_vmap only check for NULL, and would
have dereferenced an ERR_PTR and panic'd if one was ever
returned. This is not consistent with the rest of the dma buf
APIs, but matches the expectations of all of the callers.
Signed-off-by: Colin Cross <ccross@android.com>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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|---|---|---|
| .. | ||
| common | ||
| dvb-core | ||
| dvb-frontends | ||
| firewire | ||
| i2c | ||
| mmc | ||
| parport | ||
| pci | ||
| platform | ||
| radio | ||
| rc | ||
| tuners | ||
| usb | ||
| v4l2-core | ||
| Kconfig | ||
| Makefile | ||
| media-device.c | ||
| media-devnode.c | ||
| media-entity.c | ||