From: Chris Metcalf <cmetcalf@tilera.com>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>,
linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: situation with signals
Date: Wed, 27 Oct 2010 17:02:10 -0400 [thread overview]
Message-ID: <4CC89352.7020808@tilera.com> (raw)
In-Reply-To: <9lYpY1#WLHA.1516@exchange1.tad.internal.tilera.com>
On 9/24/2010 9:33 AM, Arnd Bergmann wrote:
> On Friday 24 September 2010, Al Viro wrote:
>> There are several interesting issues in arch/*/*/*signal* (besides
>> shoggoths starting to show up when one reads that code) and I'd been crawling
>> through that area for the last few weeks. Here are more or less common
>> issues; there are really arch-specific bugs (e.g. roothole on frv that
>> used to allow reading kernel memory by setting the right sa_handler), but
>> that's a separate story.
>
> I still plan to make a counterpart to the asm-generic headers with an
> example architecture that new architectures can copy from. Signal handling
> is one of the areas that I have very limited understanding of. Did you
> encounter any architecture that basically gets signal handling right and that
> can serve as a positive example to others?
>
> arch/tile/kernel/signal.c was the last one that got merged and I tried
> to direct the maintainer in the right direction as much as I could, but
> there are a lot of things I didn't know about.
(Sorry for the belated reply.)
I set aside this thread to look at when I had a minute, and I believe there
is just one of the signal issues present in the tile code. The fix is to
reset regs->fault to something other than the "syscall" fault type when
exiting from do_signal(), so I'll submit that up for 2.6.37 shortly.
Otherwise I think tile is doing things right, though I admit, the signal
support is pretty deep magic generally.
--
Chris Metcalf, Tilera Corp.
http://www.tilera.com
WARNING: multiple messages have this Message-ID (diff)
From: Chris Metcalf <cmetcalf@tilera.com>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>, <linux-arch@vger.kernel.org>,
<linux-kernel@vger.kernel.org>
Subject: Re: situation with signals
Date: Wed, 27 Oct 2010 17:02:10 -0400 [thread overview]
Message-ID: <4CC89352.7020808@tilera.com> (raw)
In-Reply-To: <9lYpY1#WLHA.1516@exchange1.tad.internal.tilera.com>
On 9/24/2010 9:33 AM, Arnd Bergmann wrote:
> On Friday 24 September 2010, Al Viro wrote:
>> There are several interesting issues in arch/*/*/*signal* (besides
>> shoggoths starting to show up when one reads that code) and I'd been crawling
>> through that area for the last few weeks. Here are more or less common
>> issues; there are really arch-specific bugs (e.g. roothole on frv that
>> used to allow reading kernel memory by setting the right sa_handler), but
>> that's a separate story.
>
> I still plan to make a counterpart to the asm-generic headers with an
> example architecture that new architectures can copy from. Signal handling
> is one of the areas that I have very limited understanding of. Did you
> encounter any architecture that basically gets signal handling right and that
> can serve as a positive example to others?
>
> arch/tile/kernel/signal.c was the last one that got merged and I tried
> to direct the maintainer in the right direction as much as I could, but
> there are a lot of things I didn't know about.
(Sorry for the belated reply.)
I set aside this thread to look at when I had a minute, and I believe there
is just one of the signal issues present in the tile code. The fix is to
reset regs->fault to something other than the "syscall" fault type when
exiting from do_signal(), so I'll submit that up for 2.6.37 shortly.
Otherwise I think tile is doing things right, though I admit, the signal
support is pretty deep magic generally.
--
Chris Metcalf, Tilera Corp.
http://www.tilera.com
next prev parent reply other threads:[~2010-10-27 21:02 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-09-23 22:11 situation with signals Al Viro
2010-09-24 13:33 ` Arnd Bergmann
[not found] ` <9lYpY1#WLHA.1516@exchange1.tad.internal.tilera.com>
2010-10-27 21:02 ` Chris Metcalf [this message]
2010-10-27 21:02 ` Chris Metcalf
2010-10-27 21:37 ` Al Viro
2010-10-27 22:51 ` Chris Metcalf
2010-10-27 22:51 ` Chris Metcalf
2010-10-27 23:30 ` Al Viro
2010-10-28 19:47 ` [PATCH] arch/tile: don't allow user code to set the PL via ptrace or signal return Chris Metcalf
2010-10-28 19:47 ` Chris Metcalf
2010-10-28 19:03 ` [PATCH] arch/tile: correct double syscall restart for nested signals Chris Metcalf
2010-10-28 19:03 ` Chris Metcalf
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