Re: [PATCH 1/2 v2] kprobe: Do not use uaccess functions to access kernel memory that can fault

From: Steven Rostedt
Date: Thu Feb 21 2019 - 09:36:31 EST

On Thu, 21 Feb 2019 16:52:52 +0900
Masami Hiramatsu <mhiramat@xxxxxxxxxx> wrote:

> Basically OK to me.
> Could you use probe_kernel_read() in this context, since probe_mem_read() is a
> wrapper function for template code.
> With that change,
> Acked-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>

This already hit Linus's tree. I was able to reproduce the crash, so I
streamlined it. I should have still pushed more for your ack first.
Sorry about that.

For some reason, I thought the change was in the generic probe code,
and accepted the probe_mem_read(). Anyway, did you want to send a patch
to change it to probe_kernel_read(), for the merge window?

> And for the long term, I need to find more efficient (or smarter) way to do it,
> like strnlen_user() does.



-- Steve