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:

quoted

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