From: Kees Cook <keescook@chromium.org>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: LKML <linux-kernel@vger.kernel.org>,
x86@kernel.org, linux-arch@vger.kernel.org,
Will Deacon <will@kernel.org>, Arnd Bergmann <arnd@arndb.de>,
Mark Rutland <mark.rutland@arm.com>,
Keno Fischer <keno@juliacomputing.com>,
Paolo Bonzini <pbonzini@redhat.com>,
kvm@vger.kernel.org
Subject: Re: [patch V3 02/13] entry: Provide generic syscall exit function
Date: Thu, 16 Jul 2020 13:55:11 -0700 [thread overview]
Message-ID: <202007161354.62030182F@keescook> (raw)
In-Reply-To: <20200716185424.116500611@linutronix.de>
On Thu, Jul 16, 2020 at 08:22:10PM +0200, Thomas Gleixner wrote:
> From: Thomas Gleixner <tglx@linutronix.de>
>
> Like syscall entry all architectures have similar and pointlessly different
> code to handle pending work before returning from a syscall to user space.
>
> 1) One-time syscall exit work:
> - rseq syscall exit
> - audit
> - syscall tracing
> - tracehook (single stepping)
>
> 2) Preparatory work
> - Exit to user mode loop (common TIF handling).
> - Architecture specific one time work arch_exit_to_user_mode_prepare()
> - Address limit and lockdep checks
>
> 3) Final transition (lockdep, tracing, context tracking, RCU). Invokes
> arch_exit_to_user_mode() to handle e.g. speculation mitigations
>
> Provide a generic version based on the x86 code which has all the RCU and
> instrumentation protections right.
>
> Provide a variant for interrupt return to user mode as well which shares
> the above #2 and #3 work items.
>
> After syscall_exit_to_user_mode() and irqentry_exit_to_user_mode() the
> architecture code just has to return to user space. The code after
> returning from these functions must not be instrumented.
>
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This looks correct to me. Did you happen to run the seccomp selftests
under this series?
Reviewed-by: Kees Cook <keescook@chromium.org>
--
Kees Cook
next prev parent reply other threads:[~2020-07-16 20:55 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-16 18:22 [patch V3 00/13] entry, x86, kvm: Generic entry/exit functionality for host and guest Thomas Gleixner
2020-07-16 18:22 ` [patch V3 01/13] entry: Provide generic syscall entry functionality Thomas Gleixner
2020-07-16 20:52 ` Kees Cook
2020-07-16 21:55 ` Thomas Gleixner
2020-07-17 17:49 ` Kees Cook
2020-07-17 19:29 ` Thomas Gleixner
2020-07-17 21:56 ` Andy Lutomirski
2020-07-18 14:16 ` Thomas Gleixner
2020-07-18 14:41 ` Andy Lutomirski
2020-07-19 10:17 ` Thomas Gleixner
2020-07-19 15:25 ` Andy Lutomirski
2020-07-20 6:50 ` Thomas Gleixner
2020-07-27 22:28 ` Andy Lutomirski
2020-07-16 18:22 ` [patch V3 02/13] entry: Provide generic syscall exit function Thomas Gleixner
2020-07-16 20:55 ` Kees Cook [this message]
2020-07-16 21:28 ` Thomas Gleixner
2020-07-16 18:22 ` [patch V3 03/13] entry: Provide generic interrupt entry/exit code Thomas Gleixner
2020-07-16 18:22 ` [patch V3 04/13] entry: Provide infrastructure for work before exiting to guest mode Thomas Gleixner
2020-07-16 18:22 ` [patch V3 05/13] x86/entry: Consolidate check_user_regs() Thomas Gleixner
2020-07-16 20:56 ` Kees Cook
2020-07-16 18:22 ` [patch V3 06/13] x86/entry: Consolidate 32/64 bit syscall entry Thomas Gleixner
2020-07-16 18:22 ` [patch V3 07/13] x86/ptrace: Provide pt_regs helpers for entry/exit Thomas Gleixner
2020-07-16 20:57 ` Kees Cook
2020-07-16 18:22 ` [patch V3 08/13] x86/entry: Use generic syscall entry function Thomas Gleixner
2020-07-16 21:13 ` Kees Cook
2020-07-16 21:33 ` Thomas Gleixner
2020-07-16 18:22 ` [patch V3 09/13] x86/entry: Use generic syscall exit functionality Thomas Gleixner
2020-07-16 18:22 ` [patch V3 10/13] x86/entry: Cleanup idtentry_entry/exit_user Thomas Gleixner
2020-07-16 18:22 ` [patch V3 11/13] x86/entry: Use generic interrupt entry/exit code Thomas Gleixner
2020-07-16 18:22 ` [patch V3 12/13] x86/entry: Cleanup idtentry_enter/exit Thomas Gleixner
2020-07-16 18:22 ` [patch V3 13/13] x86/kvm: Use generic exit to guest work function Thomas Gleixner
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