Re: [RFC][PATCH] x86/mm: Sync all vmalloc mappings before text_poke()

Joerg Roedel
2020-04-29T16:20:31Z

On Wed, Apr 29, 2020 at 06:17:47PM +0200, Joerg Roedel wrote:
> On Wed, Apr 29, 2020 at 10:07:31AM -0400, Steven Rostedt wrote:
> > Talking with Mathieu about this on IRC, he pointed out that my code does
> > have a vzalloc() that is called:
> >
> > in trace_pid_write()
> >
> > pid_list->pids = vzalloc((pid_list->pid_max + 7) >> 3);
> >
> > This is done when -P1,2 is on the trace-cmd command line.
>
> And that buffer is written to at any function entry?

What I meant to say, is it possible that the page-fault handler does not
complete because at its beginning it calls into trace-code and faults
again on the same address?

Regards,

Joerg