Re: [PATCH] ftrace/x86: Add a comment to why we take text_mutex in ftrace_arch_code_modify_prepare()

[Steven Rostedt]

On Thu, 27 Jun 2019 20:21:09 -0500
Josh Poimboeuf <jpoimboe@xxxxxxxxxx> wrote:

> On Thu, Jun 27, 2019 at 09:18:19PM -0400, Steven Rostedt wrote:
> > 
> > From: "Steven Rostedt (VMware)" <rostedt@xxxxxxxxxxx>
> > 
> > Taking the text_mutex in ftrace_arch_code_modify_prepare() is to fix a
> > race against module loading and live kernel patching that might try to
> > change the text permissions while ftrace has it as read/write. This
> > really needs to be documented in the code. Add a comment that does such.
> > 
> > Suggested-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
> > Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>

 
> 
> Reviewed-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
> 

Thanks!

-- Steve