[PATCH 4/4] dma-buf: document fd flags and O_CLOEXEC requirement

From: Daniel Vetter
Date: Sun Mar 18 2012 - 19:20:41 EST


Otherwise subsystems will get this wrong and end up with and second
export ioctl with the flag and O_CLOEXEC support added.

Signed-Off-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
---
Documentation/dma-buf-sharing.txt | 5 +++++
1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/Documentation/dma-buf-sharing.txt b/Documentation/dma-buf-sharing.txt
index 9f3aeef..087e261 100644
--- a/Documentation/dma-buf-sharing.txt
+++ b/Documentation/dma-buf-sharing.txt
@@ -319,6 +319,11 @@ Miscellaneous notes
- Any exporters or users of the dma-buf buffer sharing framework must have
a 'select DMA_SHARED_BUFFER' in their respective Kconfigs.

+- To avoid the wrath of userspace library writers exporting subsystems must have
+ a flag parameter in the ioctl that creates the dma-buf fd which needs to
+ support at least the O_CLOEXEC fd flag. This needs to be passed in the flag
+ parameter of dma_buf_export.
+
References:
[1] struct dma_buf_ops in include/linux/dma-buf.h
[2] All interfaces mentioned above defined in include/linux/dma-buf.h
--
1.7.7.5

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