On Thu, Aug 15, 2024 at 04:26:47PM +0100, Mark Brown wrote:

On Thu, Aug 15, 2024 at 03:20:52PM +0000, Edgecombe, Rick P wrote:

quoted

FYI - If you want to have more complete guard gaps, you need to do this for arm
too:
https://lore.kernel.org/linux-mm/20240326021656.202649-14-rick.p.edgecombe@intel.com/ (local)

quoted

Using VM_SHADOW_STACK only gets you part of the way there.

Oh, thanks for the heads up - I'd missed that.

Looking at this I think it makes sense to do as was done for x86 and
split this out into a separate series (part of why I'd missed it),
updating the generic implementation to do this by default.  That'll
touch a bunch of architectures and the series is already quite big,
it's not really an ABI impact.