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

[Steven Rostedt]

On Sat, 23 Feb 2019 12:47:46 +0900
Masami Hiramatsu <mhiramat@xxxxxxxxxx> wrote:

> Since kprobes handler runs in IRQ context, we can not use access_ok() in it.
> (only on x86 + CONFIG_DEBUG_ATOMIC_SLEEP=y)

Is it really IRQ context or exception context? That is, one
(interrupts) happen for any task, but exceptions happen because of the
software that is executed (like a breakpoint). Although you can have a
kprobe trigger in an interrupt handler (where user access wouldn't make
sense anyway). But there should be no problem with user access from an
exception handler.

-- Steve