Re:Google developing own CPUs for Chromebook laptops
by Someone on Saturday October 02, 2021 @06:13PM
(#28732585)
It doesn’t need to use them, but it must be aware of them, insofar as they may introduce security problems.
As an example, if the kernel doesn’t know of DMA channels, and it requires setup code to prevent user-level code from using them to copy across process boundaries, the kernel will run fine, but have glaring security problems.
Re:Google developing own CPUs for Chromebook laptops
by surajrmal on Saturday October 02, 2021 @06:53PM
(#28732832)
What dma channels doesn't require mapping registers into the user space process to work? There aren't usually magic instructions you have to opt into disabling as far as I know.
As an example, if the kernel doesn’t know of DMA channels, and it requires setup code to prevent user-level code from using them to copy across process boundaries, the kernel will run fine, but have glaring security problems.