[PATCH v2 23/31] arm64: Debugging support

[Will Deacon]

On Mon, Aug 20, 2012 at 10:07:54AM +0100, Will Deacon wrote:
> On Fri, Aug 17, 2012 at 08:06:07AM +0100, Arnd Bergmann wrote:
> > Sorry for the dumb question, but why do you even need PTRACE_GET_THREAD_AREA
> > for 64 bit tasks? I thought the thread pointer is a GPR, or is this just
> > for compat tasks?
> 
> The TLS is stored in a co-processor register which is read-only for
> userspace.

I should elaborate: the register is RW for AArch64 tasks, RO for aarch32
tasks (although that doesn't affect the need for the ptrace request).

Will