• Steven Rostedt (Red Hat)'s avatar
    ftrace/x86: Use breakpoints for converting function graph caller · 87fbb2ac
    Steven Rostedt (Red Hat) authored
    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: 08d636b6 "ftrace/x86: Have arch x86_64 use breakpoints instead of stop machine"
    Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
    87fbb2ac
ftrace.c 18 KB