ptrace: move clearing of TIF_SYSCALL_EMU flag to core

While the TIF_SYSCALL_EMU is set in ptrace_resume independent of any
architecture, currently only powerpc and x86 unset the TIF_SYSCALL_EMU
flag in ptrace_disable which gets called from ptrace_detach.

Let's move the clearing of TIF_SYSCALL_EMU flag to __ptrace_unlink
which gets executed from ptrace_detach and also keep it along with
or close to clearing of TIF_SYSCALL_TRACE.

Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 5710d07e67cf..ab14654b2436 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -118,6 +118,9 @@ void __ptrace_unlink(struct task_struct *child)
         BUG_ON(!child->ptrace);
 
         clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
+#ifdef TIF_SYSCALL_EMU
+        clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
+#endif
 
         child->parent = child->real_parent;
         list_del_init(&child->ptrace_entry);