Re: [PATCH v15 00/17] arm64: untag user pointers passed to the kernel

On 5/21/19 6:04 PM, Kees Cook wrote:

As an aside: I think Sparc ADI support in Linux actually side-stepped this[1] (i.e. chose "solution 1"): "All addresses passed to kernel must be non-ADI tagged addresses." (And sadly, "Kernel does not enable ADI for kernel code.") I think this was a mistake we should not repeat for arm64 (we do seem to be at least in agreement about this, I think).

[1] https://lore.kernel.org/patchwork/patch/654481/

That is a very early version of the sparc ADI patch. Support for tagged addresses in syscalls was added in later versions and is in the patch that is in the kernel.

That part "Kernel does not enable ADI for kernel code." is correct. It is a possible enhancement for future.

-- Khalid