From: Samuel Thibault <samuel.thibault@inria.fr>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: linux-kernel@vger.kernel.org,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
x86@kernel.org, olivier.aumage@inria.fr, yannick.martin@inria.fr
Subject: Re: X86_64 BUG: missing FS/GS LDT reload on fork()
Date: Sat, 24 Apr 2010 01:01:21 +0200 [thread overview]
Message-ID: <20100423230121.GA4563@const.famille.thibault.fr> (raw)
In-Reply-To: <4BD1E061.8030605@zytor.com>
Hello,
H. Peter Anvin, le Fri 23 Apr 2010 11:01:05 -0700, a écrit :
> On 04/23/2010 10:04 AM, Samuel Thibault wrote:
> > I have an issue with FS/GS LDT reload in the child of fork(). The
> > attached testcase fails quite often. It sets an LDT entry up, uses
> > prctl to set gs's base to a 64bit value, then loads gs with the LDT
> > entry. The LDT entry is now in effect. After a fork call, the LDT entry
> > is not in effect any more, the 64bit base is back!
>
> Okay... I have to say that I'm more than a bit confused why you're doing
> this,
:D
I'm fixing a user-level thread library with TLS support.
> The following patch looks like it should address that.
Indeed, it fixes the issue here.
Samuel
next prev parent reply other threads:[~2010-04-23 23:01 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-23 17:04 Samuel Thibault
2010-04-23 18:01 ` H. Peter Anvin
2010-04-23 23:01 ` Samuel Thibault [this message]
2010-04-23 23:42 ` [tip:x86/urgent] x86-64: Clear a 64-bit FS/GS base on fork if selector is nonzero tip-bot for H. Peter Anvin
2010-04-23 23:51 ` tip-bot for H. Peter Anvin
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