From: Pavel Machek <pavel@ucw.cz>
To: Linus Torvalds <torvalds@transmeta.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: [PATCH] Futexes IV (Fast Lightweight Userspace Semaphores)
Date: Mon, 11 Mar 2002 21:49:55 +0100 [thread overview]
Message-ID: <20020311204955.GE332@elf.ucw.cz> (raw)
In-Reply-To: <a6bjgl$a0j$1@cesium.transmeta.com> <E16jVSZ-0008FH-00@the-village.bc.nu> <a6gctg$eb6$1@penguin.transmeta.com>
In-Reply-To: <a6gctg$eb6$1@penguin.transmeta.com>
Hi!
> >So if anything its just not worth the effort of breaking the 386 setup
> >either 8). 386 SMP is a different issue but I don't see any lunatics doing
> >a 386 based sequent port thankfully.
>
> Since the only person that comes to mind that would be crazy enough to
> even _try_ to use Linux on 386-SMP is you, Alan, I'm really relieved to
> hear you say that ;)
>
> And no, it's not worth discontinuing i386 support. It just isn't
> painful enough to maintain.
>
> Note that the i386 has _long_ been a "stepchild", though: because of the
> lack of WP, the kernel simply doesn't do threaded MM correctly on a 386.
> Never has, and never will.
>
> However, the known "incorrect" case is so obscure that it's not even an
> issue - although I suspect that it means that you should not let
> untrusted users run on a i386 server machine that contains any sensitive
> data. I could cerrtainly come up with exploits that would work at least
> in theory (whether they are workable in practice I don't know).
That should mean at least warning during bootup. Checking for WP
bit... message does not suggest that WP not present means security
hole.
--- clean.2.5//arch/i386/mm/init.c Sun Mar 10 20:06:31 2002
+++ linux/arch/i386/mm/init.c Mon Mar 11 21:49:14 2002
@@ -383,7 +383,7 @@
local_flush_tlb();
if (!boot_cpu_data.wp_works_ok) {
- printk("No.\n");
+ printk("No (that's security hole).\n");
#ifdef CONFIG_X86_WP_WORKS_OK
panic("This kernel doesn't support CPU's with broken WP. Recompile it for a 386!");
#endif
Pavel
--
(about SSSCA) "I don't say this lightly. However, I really think that the U.S.
no longer is classifiable as a democracy, but rather as a plutocracy." --hpa
next prev parent reply other threads:[~2002-03-12 14:27 UTC|newest]
Thread overview: 95+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-03-05 7:01 [PATCH] Futexes IV (Fast Lightweight Userspace Semaphores) Rusty Russell
2002-03-05 21:23 ` Futexes III : performance numbers Hubertus Franke
2002-03-06 2:08 ` Rusty Russell
2002-03-06 14:28 ` Hubertus Franke
2002-03-06 17:23 ` [Lse-tech] " george anzinger
2002-03-07 0:25 ` Hubertus Franke
2002-03-07 0:35 ` Hubertus Franke
2002-03-05 22:39 ` [PATCH] Futexes IV (Fast Lightweight Userspace Semaphores) Davide Libenzi
2002-03-05 23:16 ` Hubertus Franke
2002-03-05 23:26 ` Davide Libenzi
2002-03-05 23:37 ` Peter Svensson
2002-03-05 23:50 ` Davide Libenzi
2002-03-08 0:07 ` Richard Henderson
2002-03-06 1:46 ` Rusty Russell
2002-03-06 2:03 ` Davide Libenzi
2002-03-06 7:54 ` Futexes III : performance numbers Rusty Russell
2002-03-06 14:46 ` Hubertus Franke
2002-03-06 16:13 ` Hubertus Franke
2002-03-06 20:36 ` Futexes V : Hubertus Franke
2002-03-07 4:21 ` Rusty Russell
2002-03-08 18:07 ` [PATCH] Futexes IV (Fast Lightweight Userspace Semaphores) Linus Torvalds
2002-03-08 19:03 ` Hubertus Franke
2002-03-08 19:22 ` Linus Torvalds
2002-03-08 20:29 ` Hubertus Franke
2002-03-08 20:48 ` Matthew Kirkwood
2002-03-08 21:02 ` Linus Torvalds
2002-03-08 23:15 ` Hubertus Franke
2002-03-08 23:36 ` Alan Cox
2002-03-08 23:41 ` Linus Torvalds
2002-03-08 23:56 ` Hubertus Franke
2002-03-09 2:12 ` Linus Torvalds
2002-03-11 14:14 ` Hubertus Franke
2002-03-09 0:03 ` H. Peter Anvin
2002-03-09 1:15 ` Alan Cox
2002-03-10 19:41 ` Linus Torvalds
2002-03-11 20:49 ` Pavel Machek [this message]
2002-03-10 19:58 ` Martin J. Bligh
2002-03-10 20:40 ` Alan Cox
2002-03-10 20:28 ` Martin J. Bligh
2002-03-10 21:05 ` Alan Cox
2002-03-13 7:40 ` Rusty Russell
2002-03-13 16:37 ` Alan Cox
2002-03-12 9:35 ` Helge Hafting
2002-03-08 20:40 ` Alan Cox
2002-03-08 20:57 ` Linus Torvalds
2002-03-08 23:43 ` H. Peter Anvin
2002-03-08 22:55 ` Hubertus Franke
2002-03-08 23:38 ` Alan Cox
2002-03-08 23:44 ` H. Peter Anvin
2002-03-08 20:47 ` george anzinger
2002-03-08 23:02 ` Hubertus Franke
2002-03-08 23:47 ` george anzinger
2002-03-09 1:11 ` Alan Cox
2002-03-09 1:20 ` Linus Torvalds
2002-03-09 4:49 ` Rusty Russell
2002-03-11 22:45 ` Linus Torvalds
2002-03-11 23:12 ` Hubertus Franke
2002-03-12 7:20 ` Rusty Russell
2002-03-12 14:56 ` Hubertus Franke
2002-03-13 4:02 ` Rusty Russell
2002-03-12 17:17 ` Linus Torvalds
2002-03-13 2:57 ` Rusty Russell
2002-03-09 4:51 ` Rusty Russell
2002-03-13 9:12 Martin Wirth
2002-03-13 19:41 ` Bill Davidsen
2002-03-13 19:52 ` Dave McCracken
2002-03-13 22:17 ` Bill Davidsen
2002-03-13 20:06 ` Alan Cox
2002-03-15 7:31 ` Rusty Russell
2002-03-15 8:41 ` Martin Wirth
2002-03-15 15:29 ` Hubertus Franke
2002-03-15 16:23 ` Peter Wächtler
2002-03-16 0:12 ` Rusty Russell
2002-03-16 11:23 ` Martin Wirth
2002-03-18 0:52 ` Ulrich Drepper
2002-03-19 3:28 ` Rusty Russell
2002-03-19 4:05 ` Ulrich Drepper
2002-03-20 6:20 ` Rusty Russell
2002-03-20 10:42 ` Peter Wächtler
2002-03-20 17:20 ` Ulrich Drepper
2002-03-19 8:34 ` Martin Wirth
2002-03-20 6:45 ` Rusty Russell
2002-03-21 6:48 ` Martin Wirth
2002-03-24 18:25 ` Peter Wächtler
2002-03-25 2:28 ` Rusty Russell
2002-03-25 4:46 ` Rusty Russell
2002-03-25 11:56 ` Peter Wächtler
2002-03-26 1:02 ` Rusty Russell
2002-03-26 8:17 ` Martin Wirth
2002-03-26 23:10 ` Rusty Russell
2002-03-27 21:05 ` Hubertus Franke
2002-03-27 23:53 ` Rusty Russell
2002-03-25 9:47 ` Peter Wächtler
2002-03-16 19:48 ` Peter Wächtler
2002-03-17 6:50 ` Rusty Russell
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