1. 22 Dec, 2018 13 commits
  2. 20 Dec, 2018 1 commit
    • Steven Rostedt (VMware)'s avatar
      x86/ftrace: Do not call function graph from dynamic trampolines · d2a68c4e
      Steven Rostedt (VMware) authored
      Since commit 79922b80 ("ftrace: Optimize function graph to be
      called directly"), dynamic trampolines should not be calling the
      function graph tracer at the end. If they do, it could cause the function
      graph tracer to trace functions that it filtered out.
      
      Right now it does not cause a problem because there's a test to check if
      the function graph tracer is attached to the same function as the
      function tracer, which for now is true. But the function graph tracer is
      undergoing changes that can make this no longer true which will cause
      the function graph tracer to trace other functions.
      
       For example:
      
       # cd /sys/kernel/tracing/
       # echo do_IRQ > set_ftrace_filter
       # mkdir instances/foo
       # echo ip_rcv > instances/foo/set_ftrace_filter
       # echo function_graph > current_tracer
       # echo function > instances/foo/current_tracer
      
      Would cause the function graph tracer to trace both do_IRQ and ip_rcv,
      if the current tests change.
      
      As the current tests prevent this from being a problem, this code does
      not need to be backported. But it does make the code cleaner.
      
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: x86@kernel.org
      Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
      d2a68c4e
  3. 10 Dec, 2018 6 commits
  4. 09 Dec, 2018 20 commits