From: Kees Cook <keescook@chromium.org>
To: Gabriel Krisman Bertazi <krisman@collabora.com>
Cc: tglx@linutronix.de, luto@kernel.org, x86@kernel.org,
linux-kernel@vger.kernel.org, linux-api@vger.kernel.org,
willy@infradead.org, linux-kselftest@vger.kernel.org,
shuah@kernel.org, kernel@collabora.com
Subject: Re: [PATCH v6 1/9] kernel: Support TIF_SYSCALL_INTERCEPT flag
Date: Wed, 23 Sep 2020 13:49:54 -0700 [thread overview]
Message-ID: <202009231349.4A25EAF@keescook> (raw)
In-Reply-To: <874kno6yct.fsf@collabora.com>
On Wed, Sep 23, 2020 at 04:18:26PM -0400, Gabriel Krisman Bertazi wrote:
> Kees Cook <keescook@chromium.org> writes:
>
> > On Fri, Sep 04, 2020 at 04:31:39PM -0400, Gabriel Krisman Bertazi wrote:
> >> Convert TIF_SECCOMP into a generic TI flag for any syscall interception
> >> work being done by the kernel. The actual type of work is exposed by a
> >> new flag field outside of thread_info. This ensures that the
> >> syscall_intercept field is only accessed if struct seccomp has to be
> >> accessed already, such that it doesn't incur in a much higher cost to
> >> the seccomp path.
> >>
> >> In order to avoid modifying every architecture at once, this patch has a
> >> transition mechanism, such that architectures that define TIF_SECCOMP
> >> continue to work by ignoring the syscall_intercept flag, as long as they
> >> don't support other syscall interception mechanisms like the future
> >> syscall user dispatch. When migrating TIF_SECCOMP to
> >> TIF_SYSCALL_INTERCEPT, they should adopt the semantics of checking the
> >> syscall_intercept flag, like it is done in the common entry syscall
> >> code, or even better, migrate to the common syscall entry code.
> >
> > Can we "eat" all the other flags like ptrace, audit, etc, too? Doing
> > this only for seccomp seems strange.
>
> Hi Kees, Thanks again for the review.
>
> Yes, we can, and I'm happy to follow up with that as part of my TIF
> clean up work, but can we not block the current patchset to be merged
> waiting for that, as this already grew a lot from the original feature
> submission?
In that case, I'd say just add the new TIF flag. The consolidation can
come later.
--
Kees Cook
next prev parent reply other threads:[~2020-09-23 20:49 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-04 20:31 [PATCH v6 0/9] Syscall User Dispatch Gabriel Krisman Bertazi
2020-09-04 20:31 ` [PATCH v6 1/9] kernel: Support TIF_SYSCALL_INTERCEPT flag Gabriel Krisman Bertazi
2020-09-07 10:16 ` Christian Brauner
2020-09-08 4:59 ` Gabriel Krisman Bertazi
2020-09-22 19:42 ` Kees Cook
2020-09-23 20:28 ` Gabriel Krisman Bertazi
2020-09-11 9:32 ` peterz
2020-09-11 20:08 ` Gabriel Krisman Bertazi
2020-09-24 11:24 ` Peter Zijlstra
2020-09-22 19:44 ` Kees Cook
2020-09-23 20:18 ` Gabriel Krisman Bertazi
2020-09-23 20:49 ` Kees Cook [this message]
2020-09-25 8:00 ` Thomas Gleixner
2020-09-25 16:15 ` Gabriel Krisman Bertazi
2020-09-25 20:30 ` Kees Cook
2020-09-04 20:31 ` [PATCH v6 2/9] kernel: entry: Support TIF_SYSCAL_INTERCEPT on common entry code Gabriel Krisman Bertazi
2020-09-07 10:16 ` Christian Brauner
2020-09-11 9:35 ` peterz
2020-09-11 20:11 ` Gabriel Krisman Bertazi
2020-09-04 20:31 ` [PATCH v6 3/9] x86: vdso: Expose sigreturn address on vdso to the kernel Gabriel Krisman Bertazi
2020-09-22 19:40 ` Kees Cook
2020-09-04 20:31 ` [PATCH v6 4/9] signal: Expose SYS_USER_DISPATCH si_code type Gabriel Krisman Bertazi
2020-09-07 10:15 ` Christian Brauner
2020-09-22 19:39 ` Kees Cook
2020-09-04 20:31 ` [PATCH v6 5/9] kernel: Implement selective syscall userspace redirection Gabriel Krisman Bertazi
2020-09-05 11:24 ` Matthew Wilcox
2020-09-11 9:44 ` peterz
2020-09-04 20:31 ` [PATCH v6 6/9] kernel: entry: Support Syscall User Dispatch for common syscall entry Gabriel Krisman Bertazi
2020-09-07 10:15 ` Christian Brauner
2020-09-07 14:15 ` Andy Lutomirski
2020-09-07 14:25 ` Christian Brauner
2020-09-07 20:20 ` Andy Lutomirski
2020-09-11 9:46 ` peterz
2020-09-04 20:31 ` [PATCH v6 7/9] x86: Enable Syscall User Dispatch Gabriel Krisman Bertazi
2020-09-22 19:37 ` Kees Cook
2020-09-23 20:23 ` Gabriel Krisman Bertazi
2020-09-04 20:31 ` [PATCH v6 8/9] selftests: Add kselftest for syscall user dispatch Gabriel Krisman Bertazi
2020-09-22 19:35 ` Kees Cook
2020-09-04 20:31 ` [PATCH v6 9/9] doc: Document Syscall User Dispatch Gabriel Krisman Bertazi
2020-09-22 19:35 ` Kees Cook
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