commit 43fe4bc236d667257eeebfb4f6bcbe2b92aea455
Author: Mark Wielaard <mark@klomp.org>
Date:   Fri Dec 14 14:32:27 2018 +0100

    arm64: Fix PTRACE_TRACEME memcheck/tests/linux/getregset.vgtest testcase.
    
    The sys_ptrace post didn't mark the thread as being in traceme mode.
    This occassionally would make the memcheck/tests/linux/getregset.vgtest
    testcase fail. With this patch it reliably passes.

diff --git a/coregrind/m_syswrap/syswrap-arm64-linux.c b/coregrind/m_syswrap/syswrap-arm64-linux.c
index 9ef54b4..650f5b9 100644
--- a/coregrind/m_syswrap/syswrap-arm64-linux.c
+++ b/coregrind/m_syswrap/syswrap-arm64-linux.c
@@ -499,6 +499,9 @@ PRE(sys_ptrace)
 POST(sys_ptrace)
 {
    switch (ARG1) {
+   case VKI_PTRACE_TRACEME:
+         ML_(linux_POST_traceme)(tid);
+         break;
    case VKI_PTRACE_PEEKTEXT:
    case VKI_PTRACE_PEEKDATA:
    case VKI_PTRACE_PEEKUSR: