From: Pavel Machek <pavel@ucw.cz>
To: Stas Sergeev <stsp@aknet.ru>
Cc: Alan Cox <alan@redhat.com>,
Linux kernel <linux-kernel@vger.kernel.org>,
Linus Torvalds <torvalds@osdl.org>,
Petr Vandrovec <vandrove@vc.cvut.cz>,
Denis Vlasenko <vda@port.imtp.ilyichevsk.odessa.ua>
Subject: Re: [patch] x86: fix ESP corruption CPU bug
Date: Sun, 13 Mar 2005 21:10:20 +0100 [thread overview]
Message-ID: <20050313201020.GB8231@elf.ucw.cz> (raw)
In-Reply-To: <42348474.7040808@aknet.ru>
Hi!
> @@ -257,8 +265,31 @@
> movl TI_flags(%ebp), %ecx
> testw $_TIF_ALLWORK_MASK, %cx # current->work
> jne syscall_exit_work
> +
> restore_all:
> - RESTORE_ALL
> + movl EFLAGS(%esp), %eax # mix EFLAGS, SS and CS
> + movb OLDSS(%esp), %ah
> + movb CS(%esp), %al
> + andl $(VM_MASK | (4 << 8) | 3), %eax
> + cmpl $((4 << 8) | 3), %eax
> + je ldt_ss # returning to user-space with LDT SS
All common linux apps use same %ss, no? Perhaps it would be more
efficient to just check if %ss == 0x7b, and proceed directly to
restore_nocheck if not?
Or perhaps we could only enable this code after application loads
custom ldt?
Pavel
--
People were complaining that M$ turns users into beta-testers...
...jr ghea gurz vagb qrirybcref, naq gurl frrz gb yvxr vg gung jnl!
next prev parent reply other threads:[~2005-03-13 20:10 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-03-13 18:20 [patch] x86: fix ESP corruption CPU bug Stas Sergeev
2005-03-13 18:52 ` Grzegorz Kulewski
2005-03-13 19:11 ` Stas Sergeev
2005-03-13 19:37 ` Ondrej Zary
2005-03-13 19:46 ` Stas Sergeev
2005-03-13 20:02 ` Pavel Machek
2005-03-13 20:10 ` Pavel Machek [this message]
2005-03-13 20:55 ` Stas Sergeev
2005-03-13 21:13 ` Linus Torvalds
2005-03-13 22:06 ` [patch] x86: fix ESP corruption CPU bug (take 2) Stas Sergeev
2005-03-14 19:29 ` Alan Cox
2005-03-14 19:59 ` Stas Sergeev
2005-03-15 3:34 ` Andrew Morton
2005-03-15 10:48 ` x86: spin_unlock(), spin_unlock_irq() & others are out of line ? Eric Dumazet
2005-03-15 19:44 ` Lee Revell
2005-03-15 19:48 ` [patch] x86: fix ESP corruption CPU bug (take 2) Stas Sergeev
2005-03-13 23:17 ` [patch] x86: fix ESP corruption CPU bug Pavel Machek
2005-03-13 23:54 ` Linus Torvalds
2005-03-14 0:16 ` Linus Torvalds
2005-03-14 4:52 ` Stas Sergeev
2005-03-14 9:34 ` Andi Kleen
2005-03-14 10:37 ` [BUG?] x86_64 : Can not read /dev/kmem ? Eric Dumazet
2005-03-21 19:37 ` Andi Kleen
2005-03-22 15:24 ` Andi Kleen
2005-03-14 15:21 ` [patch] x86: fix ESP corruption CPU bug Jakob Eriksson
2005-03-14 17:03 ` linux-os
2005-03-14 17:10 ` Pavel Machek
2005-03-14 19:24 ` Brian Gerst
2005-03-14 20:21 ` Stas Sergeev
2005-03-14 18:02 ` Stas Sergeev
2005-03-14 17:29 ` Stas Sergeev
-- strict thread matches above, loose matches on Subject: below --
2005-03-14 11:10 Zoltan Boszormenyi
2005-01-03 23:39 Stas Sergeev
2005-01-04 0:01 ` Linus Torvalds
2005-01-04 1:58 ` Stas Sergeev
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