From: Thomas Gleixner <tglx@linutronix.de>
To: Kees Cook <keescook@chromium.org>
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,
Gabriel Krisman Bertazi <krisman@collabora.com>
Subject: Re: [patch V4 10/15] x86/entry: Use generic syscall entry function
Date: Wed, 22 Jul 2020 20:25:55 +0200 [thread overview]
Message-ID: <87wo2vz9sc.fsf@nanos.tec.linutronix.de> (raw)
In-Reply-To: <202007211440.BEF76E2@keescook>
Kees,
Kees Cook <keescook@chromium.org> writes:
> On Tue, Jul 21, 2020 at 12:57:16PM +0200, Thomas Gleixner wrote:
>
> This doesn't look very expensive, and they certain indicate really bad
> conditions. Does this need to be behind a CONFIG? (Whatever the answer,
> we can probably make those changes in a later series -- some of these
> also look not arch-specific...)
The most expensive part is native_save_flags(). The extra branches could
be visible in benchmarks, but its a good question whether this should be
just enabled.
I just keep it as is for now as I would need to make the flags and the
on_thread_stack() part x86 specific anyway, but yes we can revisit that
once we agreed on the general direction of this.
Thanks,
tglx
next prev parent reply other threads:[~2020-07-22 18:25 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-21 10:57 [patch V4 00/15] entry, x86, kvm: Generic entry/exit functionality for host and guest Thomas Gleixner
2020-07-21 10:57 ` [patch V4 01/15] seccomp: Provide stub for __secure_computing() Thomas Gleixner
2020-07-21 21:21 ` Kees Cook
2020-07-21 10:57 ` [patch V4 02/15] entry: Provide generic syscall entry functionality Thomas Gleixner
2020-07-21 21:38 ` Kees Cook
2020-07-22 7:34 ` Thomas Gleixner
2020-07-22 7:54 ` peterz
2020-07-21 10:57 ` [patch V4 03/15] entry: Provide generic syscall exit function Thomas Gleixner
2020-07-27 22:37 ` Andy Lutomirski
2020-07-21 10:57 ` [patch V4 04/15] entry: Provide generic interrupt entry/exit code Thomas Gleixner
2020-07-27 22:39 ` Andy Lutomirski
2020-07-29 12:18 ` Thomas Gleixner
2020-07-21 10:57 ` [patch V4 05/15] entry: Provide infrastructure for work before exiting to guest mode Thomas Gleixner
2020-07-21 10:57 ` [patch V4 06/15] x86/entry: Consolidate check_user_regs() Thomas Gleixner
2020-07-27 22:39 ` Andy Lutomirski
2020-07-21 10:57 ` [patch V4 07/15] x86/entry: Consolidate 32/64 bit syscall entry Thomas Gleixner
2020-07-21 10:57 ` [patch V4 08/15] x86/entry: Move user return notifier out of loop Thomas Gleixner
2020-07-21 10:57 ` [patch V4 09/15] x86/ptrace: Provide pt_regs helper for entry/exit Thomas Gleixner
2020-07-21 10:57 ` [patch V4 10/15] x86/entry: Use generic syscall entry function Thomas Gleixner
2020-07-21 21:47 ` Kees Cook
2020-07-22 18:25 ` Thomas Gleixner [this message]
2020-07-21 10:57 ` [patch V4 11/15] x86/entry: Use generic syscall exit functionality Thomas Gleixner
2020-07-21 21:47 ` Kees Cook
2020-07-21 10:57 ` [patch V4 12/15] x86/entry: Cleanup idtentry_entry/exit_user Thomas Gleixner
2020-07-21 21:48 ` Kees Cook
2020-07-21 10:57 ` [patch V4 13/15] x86/entry: Use generic interrupt entry/exit code Thomas Gleixner
2020-07-21 10:57 ` [patch V4 14/15] x86/entry: Cleanup idtentry_enter/exit Thomas Gleixner
2020-07-21 21:48 ` Kees Cook
2020-07-21 10:57 ` [patch V4 15/15] x86/kvm: Use generic exit to guest work function Thomas Gleixner
2020-07-21 20:27 ` Sean Christopherson
2020-07-22 7:40 ` Thomas Gleixner
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