On Thu, Mar 5, 2020 at 4:55 PM Peter Zijlstra <peterz(a)infradead.org> wrote:
On Thu, Mar 05, 2020 at 04:23:11PM +0100, Dmitry Vyukov wrote:
> Compilers just don't allow this: asking to inline sanitized function
> into a non-sanitized function. But I don't know the ptrace/alternative
> code good enough to suggest the right alternative (don't call
> user_mode, copy user_mode, or something else).
Does it work if we inline into a .c file and build it with:
KASAN_SANITIZE := n
UBSAN_SANITIZE := n
KCOV_INSTRUMENT := n
Which would be effectively the very same, just more cumbersome.
I think it should work, because then user_mode will also not be instrumented.
> > Maybe we could replace no_sanitize with calls to
> > kasan_disable_current/kasan_enable_current around the section of code
> > where you don't want to see kasan reports.
> It's not that we don't want to see the reports, the problem is that the
> execution context is too fragile to call into random code. We've not yet
> completely set up a normal C environment, even though we're more or less
> running C.
> This is very early exception entry where we still need to frob hardware
> state and set up things.