The kdbuswreck [LWN.net]

The kdbuswreck

Posted Apr 23, 2015 8:49 UTC (Thu) by smurf (subscriber, #17840)
In reply to: The kdbuswreck by markhahn
Parent article: The kdbuswreck

So what would you consider to be reasonable? I'd regard the ability to securely pass large amounts of data without copying them at all, let alone multiple times, to be reasonable enough in itself.

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The kdbuswreck

Posted Apr 23, 2015 11:25 UTC (Thu) by mstefani (guest, #31644) [Link] (2 responses)

Isn't that functionality already in? kdbus uses memfd for that and memfd was uncontroversial and generic.

The kdbuswreck

Posted Apr 30, 2015 10:23 UTC (Thu) by metux-its (guest, #102293) [Link] (1 responses)

And even memfd isn't required for that.

Anybody heared of mmap() ? ;-o

The kdbuswreck

Posted Apr 30, 2015 20:00 UTC (Thu) by cesarb (subscriber, #6266) [Link]

> And even memfd isn't required for that. Anybody heared of mmap() ?

The point of using a memfd is that it can be sealed, so there's no risk of a TOCTOU vulnerability in the receiver.

With mmap(), the sender can change what the receiver sees while the receiver is looking at it.