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

From: Joerg Roedel
Date: Wed Apr 29 2020 - 10:10:09 EST


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.

Yeah, I was guessing something like this, init_mm has a mapping which
poking_mm has not. I currently try to reproduce this on one of my
machines.

Regards,

Joerg