Re: [for-next][PATCH 09/33] selftests: ftrace: Add test to test reading of set_ftrace_file

[Steven Rostedt]

On Mon, 22 May 2017 12:23:08 +0900
Masami Hiramatsu <mhiramat@xxxxxxxxxx> wrote:

> Hi Steve,
> 
> On Fri, 21 Apr 2017 17:30:29 -0400
> Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
> 
> > From: "Steven Rostedt (VMware)" <rostedt@xxxxxxxxxxx>
> > 
> > The set_ftrace_file lists both functions that are filtered, as well as
> > function probes (triggers) that are attached to a function, like traceon or
> > stacktrace, etc. The reading of this file is not as trivial as most pseudo
> > files are, and there's been various bugs that have appeared in the past
> > when there's a mix of probes and functions listed. There's also a difference
> > when reading the file using dd with a block size of 1.  
> 
> Would you know which commit fixed this dd/cat differences on
> set_ftrace_filter? When I've run this test on 4.9-stable kernel,
> it failed because the result of "dd -bs=1" and "cat" on
> set_ftrace_filter were different.
>

Probably one of the patches in this series before this one.

-- Steve