Enable thread local storage support on arm64.

Linux use the task.thread.uw.tp_value field to store the
TLS pointer on arm64 platform, and we use a similar way
in gvisor to store it in the arch/State struct.

Signed-off-by: Haibo Xu <haibo.xu@arm.com>
Change-Id: Ie76b5c6d109bc27ccfd594008a96753806db7764

1 files changed, 14 insertions, 0 deletions

diff --git a/pkg/sentry/platform/ptrace/ptrace_amd64.go b/pkg/sentry/platform/ptrace/ptrace_amd64.go
index db0212538..24fc5dc62 100644
--- a/pkg/sentry/platform/ptrace/ptrace_amd64.go
+++ b/pkg/sentry/platform/ptrace/ptrace_amd64.go
@@ -31,3 +31,17 @@ func fpRegSet(useXsave bool) uintptr {
 func stackPointer(r *syscall.PtraceRegs) uintptr {
 	return uintptr(r.Rsp)
 }
+
+// x86 use the fs_base register to store the TLS pointer which can be
+// get/set in "func (t *thread) get/setRegs(regs *syscall.PtraceRegs)".
+// So both of the get/setTLS() operations are noop here.
+
+// getTLS gets the thread local storage register.
+func (t *thread) getTLS(tls *uint64) error {
+	return nil
+}
+
+// setTLS sets the thread local storage register.
+func (t *thread) setTLS(tls *uint64) error {
+	return nil
+}