From: Ingo Molnar <mingo@elte.hu>
To: Andrew Lutomirski <luto@mit.edu>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
pageexec@freemail.hu, Andi Kleen <andi@firstfloor.org>,
x86@kernel.org, Thomas Gleixner <tglx@linutronix.de>,
linux-kernel@vger.kernel.org, Jesper Juhl <jj@chaosbits.net>,
Borislav Petkov <bp@alien8.de>,
Andrew Morton <akpm@linux-foundation.org>,
Arjan van de Ven <arjan@infradead.org>,
Jan Beulich <JBeulich@novell.com>,
richard -rw- weinberger <richard.weinberger@gmail.com>,
Mikael Pettersson <mikpe@it.uu.se>,
Brian Gerst <brgerst@gmail.com>,
Louis Rilling <Louis.Rilling@kerlabs.com>,
Valdis.Kletnieks@vt.edu
Subject: Re: [PATCH v5 9/9] x86-64: Add CONFIG_UNSAFE_VSYSCALLS to feature-removal-schedule
Date: Mon, 6 Jun 2011 23:54:21 +0200 [thread overview]
Message-ID: <20110606215421.GA12079@elte.hu> (raw)
In-Reply-To: <BANLkTim8mSoifxoN=b2Gpe+WLjJyuqBR8g@mail.gmail.com>
* Andrew Lutomirski <luto@mit.edu> wrote:
> > don't even bother making it a config option for now. If we can
> > replace the vsyscall page with a page fault or int3 or whatever,
> > and it's only used for the 'time()' system call, just do it.
>
> Really?
>
> I won't personally complain about the 200+ ns hit, but I'm sure
> someone will cc: me on a regression report if there's no option.
Well, for 0.2 usecs to show up one would have to do like a million of
them per second.
Why an application would want to query the *same value* from the
kernel a million times per second is beyond me. vgettimeofday()?
Sure. But vtime()?
Thanks,
Ingo
next prev parent reply other threads:[~2011-06-06 21:54 UTC|newest]
Thread overview: 112+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-06-05 17:50 [PATCH v5 0/9] Remove syscall instructions at fixed addresses Andy Lutomirski
2011-06-05 17:50 ` [PATCH v5 1/9] x86-64: Fix alignment of jiffies variable Andy Lutomirski
2011-06-06 8:31 ` [tip:x86/vdso] " tip-bot for Andy Lutomirski
2011-06-05 17:50 ` [PATCH v5 2/9] x86-64: Document some of entry_64.S Andy Lutomirski
2011-06-06 8:31 ` [tip:x86/vdso] " tip-bot for Andy Lutomirski
2011-06-05 17:50 ` [PATCH v5 3/9] x86-64: Give vvars their own page Andy Lutomirski
2011-06-06 8:32 ` [tip:x86/vdso] " tip-bot for Andy Lutomirski
2011-06-05 17:50 ` [PATCH v5 4/9] x86-64: Remove kernel.vsyscall64 sysctl Andy Lutomirski
2011-06-06 8:32 ` [tip:x86/vdso] " tip-bot for Andy Lutomirski
2011-12-05 18:27 ` [PATCH v5 4/9] " Matthew Maurer
2011-06-05 17:50 ` [PATCH v5 5/9] x86-64: Map the HPET NX Andy Lutomirski
2011-06-06 8:33 ` [tip:x86/vdso] " tip-bot for Andy Lutomirski
2011-06-05 17:50 ` [PATCH v5 6/9] x86-64: Remove vsyscall number 3 (venosys) Andy Lutomirski
2011-06-06 8:33 ` [tip:x86/vdso] " tip-bot for Andy Lutomirski
2011-06-05 17:50 ` [PATCH v5 7/9] x86-64: Fill unused parts of the vsyscall page with 0xcc Andy Lutomirski
2011-06-06 8:34 ` [tip:x86/vdso] " tip-bot for Andy Lutomirski
2011-06-05 17:50 ` [PATCH v5 8/9] x86-64: Emulate legacy vsyscalls Andy Lutomirski
2011-06-05 19:30 ` Ingo Molnar
2011-06-05 20:01 ` Andrew Lutomirski
2011-06-06 7:39 ` Ingo Molnar
2011-06-06 9:42 ` pageexec
2011-06-06 11:19 ` Andrew Lutomirski
2011-06-06 11:56 ` pageexec
2011-06-06 12:43 ` Andrew Lutomirski
2011-06-06 13:58 ` pageexec
2011-06-06 14:07 ` Brian Gerst
2011-06-07 23:32 ` pageexec
2011-06-07 23:49 ` Andrew Lutomirski
2011-06-08 6:32 ` pageexec
2011-06-06 15:26 ` Ingo Molnar
2011-06-06 15:48 ` pageexec
2011-06-06 15:59 ` Ingo Molnar
2011-06-06 16:19 ` pageexec
2011-06-06 16:47 ` Ingo Molnar
2011-06-06 22:49 ` pageexec
2011-06-06 22:57 ` david
2011-06-07 9:07 ` Ingo Molnar
2011-06-07 6:59 ` Pekka Enberg
2011-06-07 8:30 ` Ingo Molnar
2011-06-07 23:24 ` pageexec
2011-06-08 5:55 ` Pekka Enberg
2011-06-08 6:19 ` pageexec
2011-06-08 6:48 ` Ingo Molnar
2011-06-08 9:02 ` pageexec
2011-06-08 9:11 ` Andi Kleen
2011-06-08 9:35 ` pageexec
2011-06-08 10:06 ` Andi Kleen
2011-06-08 10:26 ` pageexec
2011-06-08 10:39 ` Ingo Molnar
2011-06-08 10:35 ` Ingo Molnar
2011-06-08 9:15 ` Ingo Molnar
2011-06-08 7:16 ` Ingo Molnar
2011-06-08 9:29 ` pageexec
2011-06-06 14:01 ` Linus Torvalds
2011-06-06 14:55 ` pageexec
2011-06-06 15:33 ` Ingo Molnar
2011-06-06 15:58 ` pageexec
2011-06-06 15:41 ` Ingo Molnar
2011-06-06 8:34 ` [tip:x86/vdso] " tip-bot for Andy Lutomirski
2011-06-06 8:35 ` [tip:x86/vdso] x86-64, vdso, seccomp: Fix !CONFIG_SECCOMP build tip-bot for Ingo Molnar
2011-06-07 7:49 ` [tip:x86/vdso] x86-64: Emulate legacy vsyscalls tip-bot for Andy Lutomirski
2011-06-07 8:03 ` tip-bot for Andy Lutomirski
2011-06-05 17:50 ` [PATCH v5 9/9] x86-64: Add CONFIG_UNSAFE_VSYSCALLS to feature-removal-schedule Andy Lutomirski
2011-06-06 8:34 ` [tip:x86/vdso] " tip-bot for Andy Lutomirski
2011-06-06 8:46 ` [PATCH v5 9/9] " Linus Torvalds
2011-06-06 9:31 ` Andi Kleen
2011-06-06 10:39 ` pageexec
2011-06-06 13:56 ` Linus Torvalds
2011-06-06 18:46 ` pageexec
2011-06-06 20:40 ` Linus Torvalds
2011-06-06 20:51 ` Andrew Lutomirski
2011-06-06 21:54 ` Ingo Molnar [this message]
2011-06-06 21:45 ` Ingo Molnar
2011-06-06 21:48 ` Ingo Molnar
[not found] ` <BANLkTi==uw_h78oaep1cCOCzwY0edLUU_Q@mail.gmail.com>
2011-06-07 8:03 ` [PATCH, v6] x86-64: Emulate legacy vsyscalls Ingo Molnar
2011-06-06 21:53 ` [PATCH v5 9/9] x86-64: Add CONFIG_UNSAFE_VSYSCALLS to feature-removal-schedule pageexec
2011-06-06 14:44 ` Ingo Molnar
2011-06-06 15:01 ` pageexec
2011-06-06 15:15 ` Ingo Molnar
2011-06-06 15:29 ` pageexec
2011-06-06 16:54 ` Ingo Molnar
2011-06-06 18:59 ` pageexec
2011-06-06 19:25 ` Ingo Molnar
2011-06-07 0:34 ` pageexec
2011-06-07 9:51 ` Ingo Molnar
2011-06-07 23:24 ` pageexec
2011-06-10 11:19 ` Ingo Molnar
2011-06-14 0:48 ` pageexec
2011-06-15 19:42 ` Valdis.Kletnieks
2011-06-06 14:52 ` Ingo Molnar
2011-06-06 10:24 ` [PATCH] x86-64, vsyscalls: Rename UNSAFE_VSYSCALLS to COMPAT_VSYSCALLS Ingo Molnar
2011-06-06 11:20 ` pageexec
2011-06-06 12:47 ` Ingo Molnar
2011-06-06 12:48 ` Ingo Molnar
2011-06-06 18:04 ` pageexec
2011-06-06 19:12 ` Ingo Molnar
2011-06-07 0:02 ` pageexec
2011-06-07 9:56 ` Ingo Molnar
2011-06-07 23:24 ` pageexec
2011-06-09 6:48 ` Ingo Molnar
2011-06-09 23:33 ` pageexec
2011-06-07 10:05 ` Ingo Molnar
2011-06-07 23:24 ` pageexec
2011-06-09 7:02 ` Ingo Molnar
2011-06-09 23:33 ` pageexec
2011-06-07 10:13 ` Ingo Molnar
2011-06-07 23:24 ` pageexec
2011-06-06 12:19 ` Ted Ts'o
2011-06-06 12:33 ` Andrew Lutomirski
2011-06-06 12:37 ` Ingo Molnar
2011-06-06 14:34 ` [tip:x86/vdso] " tip-bot for Ingo Molnar
2011-06-05 20:05 ` [PATCH v5 0/9] Remove syscall instructions at fixed addresses Andrew Lutomirski
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