From: Peter Zijlstra <peterz@infradead.org>
To: Kees Cook <keescook@chromium.org>
Cc: Alexander Potapenko <glider@google.com>,
Marco Elver <elver@google.com>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
Andrew Morton <akpm@linux-foundation.org>,
Dave Hansen <dave.hansen@linux.intel.com>,
x86@kernel.org
Subject: Re: [PATCH] x86/uaccess: instrument copy_from_user_nmi()
Date: Thu, 27 Oct 2022 21:26:34 +0200 [thread overview]
Message-ID: <Y1rbanstUTfq3tb4@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <202210271155.33956B1@keescook>
On Thu, Oct 27, 2022 at 11:58:35AM -0700, Kees Cook wrote:
> I wandered around attempting to deal with in_nmi(), etc. And in
> the end just drop the attempt to cover it. It's worth noting that
> copy_from_user_nmi() exists on 1 architecture and has exactly 1
> call-site...
Yeah, back when I wrote it, it was a lot more complicated because we
could not reliably take #PF from NMI context; it did manual page-walks,
kmap_atomic()s and mempcy(). That's all fixed now and it's really mostly
a rudiment -- except for these instrumentation issues it seems.
next prev parent reply other threads:[~2022-10-27 19:26 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-25 22:17 Alexander Potapenko
2022-10-26 9:30 ` Peter Zijlstra
2022-10-26 18:38 ` Alexander Potapenko
2022-10-27 8:05 ` Peter Zijlstra
2022-10-27 18:26 ` Alexander Potapenko
2022-10-27 18:58 ` Kees Cook
2022-10-27 19:26 ` Peter Zijlstra [this message]
2022-10-27 23:24 ` Alexander Potapenko
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=Y1rbanstUTfq3tb4@hirez.programming.kicks-ass.net \
--to=peterz@infradead.org \
--cc=akpm@linux-foundation.org \
--cc=dave.hansen@linux.intel.com \
--cc=elver@google.com \
--cc=glider@google.com \
--cc=keescook@chromium.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox