From: Matthew Maurer <maurer@ugcs.caltech.edu>
To: linux-kernel@vger.kernel.org
Subject: Re: [PATCH v5 4/9] x86-64: Remove kernel.vsyscall64 sysctl
Date: Mon, 5 Dec 2011 18:27:09 +0000 (UTC) [thread overview]
Message-ID: <loom.20111205T192515-288@post.gmane.org> (raw)
In-Reply-To: 973ae803fe76f712da4b2740e66dccf452d3b1e4.1307292171.git.luto@mit.edu
Andy Lutomirski <luto <at> MIT.EDU> writes:
>
> It's unnecessary overhead in code that's supposed to be highly
> optimized. Removing it allows us to remove one of the two syscall
> instructions in the vsyscall page.
>
> The only sensible use for it is for UML users, and it doesn't fully
> address inconsistent vsyscall results on UML. The real fix for UML
> is to stop using vsyscalls entirely.
UML is not the only use case for this. Anybody who wants to be able to
trace _all_ system calls (for debugging, ptrace-based sandboxing, or a
number of other purposes) needs this.
We either need this back, or need another way to make it possible to
trace these system calls.
Apologies for the late reply, I didn't notice this change until it got
into my distribution's kernel.
--Matthew Maurer
next prev parent reply other threads:[~2011-12-05 18:30 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 ` Matthew Maurer [this message]
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
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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