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A netlink-based user-space crypto APIA netlink-based user-space crypto APIPosted Oct 24, 2010 21:58 UTC (Sun) by alonz (subscriber, #815)In reply to: A netlink-based user-space crypto API by neilbrown Parent article: A netlink-based user-space crypto API I refer to "zero-copy" in rather loose terms—not copying more than is necessary. In particular, if the application chooses input/output buffers that are suitable for DMA, I would like to perform a single DMA translation (many cryptography engines have dual-channel DMA engines, so they can read the source buffer via DMA, transform it, and write the output to the target buffer in a single pass). As for the specific API—all proposals I have seen so far look like hacks, and are rather brittle (e.g. the aio_read solution would require the driver to keep userspace pointers for longer than a single system call, which is generally considered bad taste AFAIK).
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A netlink-based user-space crypto API Posted Oct 24, 2010 23:31 UTC (Sun) by neilbrown (subscriber, #359) [Link]
One man's hack is another man's elegant design :-)
aio, by its very nature, requires the kernel to hold on to user-space pointers for longer than a single system call. This is OK because 'aio_cancel' exists to reclaim the pointer if needed.
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