1 Aug
2019
1 Aug
'19
4:45 p.m.
On 8/1/19 5:38 AM, Kevin Brodsky wrote:
This patch series only changes what is allowed or not at the syscall interface. It does not change the address space size. On arm64, TBI (Top Byte Ignore) has always been enabled for userspace, so it has never been possible to use the upper 8 bits of user pointers for addressing.
Oh, so does the address space that's available already chop that out?
If other architectures were to support a similar functionality, then I agree that a common and more generic interface (if needed) would be helpful, but as it stands this is an arm64-specific prctl, and on arm64 the address tag is defined by the architecture as bits [63:56].
It should then be an arch_prctl(), no?