linux-kernel - Re: [PATCH/RFC] signal races/bugs, losing TIF

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Tue, 5 Jun 2007 17:37:33 -0700 (PDT)
From:	Davide Libenzi <davidel@...ilserver.org>
To:	Nicholas Miell <nmiell@...cast.net>
cc:	Benjamin Herrenschmidt <benh@...nel.crashing.org>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Linux Kernel list <linux-kernel@...r.kernel.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Paul Mackerras <paulus@...ba.org>
Subject: Re: [PATCH/RFC] signal races/bugs, losing TIF_SIGPENDING and other
 woes

On Tue, 5 Jun 2007, Nicholas Miell wrote:

> On Tue, 2007-06-05 at 17:11 -0700, Davide Libenzi wrote:
> > On Tue, 5 Jun 2007, Nicholas Miell wrote:
> > 
> > > Yes, that's certainly wrong, but that's an implementation issue. I was
> > > more concerned about the design of the API.
> > > 
> > > Naively, I would expect a reads on a signalfd to return either process
> > > signals or thread signals targeted towards the thread doing the read.
> > > 
> > > What it actually does (delivering process signals or thread signals
> > > targeted towards the thread that created the signalfd) is weird.
> > > 
> > > For one, it means you can't create a single signalfd, stick it in an
> > > epoll set, and then wait on that set from multiple threads.
> > 
> > In your box threads do share the sighand, don't they? :)
> > 
> 
> I have no idea what you're trying to say, but it doesn't appear to
> address the issue I raise.

"For one, it means you can't create a single signalfd, stick it in an
 epoll set, and then wait on that set from multiple threads."

Why not?
A signalfd, like I said, is attached to the sighand, that is shared by the 
threads.



- Davide


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/