tree e6f5536215978fd41cc325fb497834c1d96bba39
parent d651aa1d68a2f0a7ee65697b04c6a92f8c0a12f2
author Steven Rostedt (Red Hat) <rostedt@goodmis.org> 1392167984 -0500
committer Steven Rostedt <rostedt@goodmis.org> 1392167984 -0500

ftrace/x86: Use breakpoints for converting function graph caller

When the conversion was made to remove stop machine and use the breakpoint
logic instead, the modification of the function graph caller is still
done directly as though it was being done under stop machine.

As it is not converted via stop machine anymore, there is a possibility
that the code could be layed across cache lines and if another CPU is
accessing that function graph call when it is being updated, it could
cause a General Protection Fault.

Convert the update of the function graph caller to use the breakpoint
method as well.

Cc: H. Peter Anvin <hpa@zytor.com>
Cc: stable@vger.kernel.org # 3.5+
Fixes: 08d636b6d4fb "ftrace/x86: Have arch x86_64 use breakpoints instead of stop machine"
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>